:root {
  color-scheme: dark;
  --ink: #080b09;
  --ink-soft: #111713;
  --moss: #17231b;
  --paper: #e8e9e2;
  --paper-soft: #d5d8ce;
  --text: #f0f2ec;
  --text-dark: #111410;
  --muted: rgba(240, 242, 236, .68);
  --muted-dark: rgba(17, 20, 16, .62);
  --gold: #cba45f;
  --line: rgba(240, 242, 236, .19);
  --line-dark: rgba(17, 20, 16, .18);
  --sans: "Microsoft YaHei UI", "Noto Sans SC", "Source Han Sans SC", "PingFang SC", sans-serif;
  --ease: cubic-bezier(.22, 1, .36, 1);
  --header-height: 82px;
  --page-pad: clamp(22px, 5vw, 84px);
}

* {
  box-sizing: border-box;
}

html {
  background: var(--ink);
  color: var(--text);
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;
  background: var(--ink);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  font-synthesis: none;
}

body.viewer-open {
  overflow: hidden;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button {
  color: inherit;
  font: inherit;
}

button:focus-visible,
a:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 4px;
}

[hidden] {
  display: none !important;
}

.page-progress {
  position: fixed;
  z-index: 300;
  inset: 0 0 auto;
  height: 3px;
  background: transparent;
}

.page-progress span {
  display: block;
  width: 100%;
  height: 100%;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left;
  will-change: transform;
}

.site-header {
  position: fixed;
  z-index: 100;
  inset: 3px 0 auto;
  height: var(--header-height);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 26px;
  padding: 0 var(--page-pad);
  border-bottom: 1px solid rgba(240, 242, 236, .16);
  background: rgba(8, 11, 9, .62);
  backdrop-filter: blur(18px) saturate(1.1);
  transition: background 260ms ease, border-color 260ms ease, opacity 260ms ease;
}

.site-header.is-solid {
  background: rgba(8, 11, 9, .94);
  border-color: rgba(240, 242, 236, .1);
}

.brand {
  width: max-content;
  display: flex;
  align-items: baseline;
  gap: 16px;
  color: var(--text);
  text-decoration: none;
}

.brand strong {
  font-size: clamp(25px, 2.2vw, 36px);
  font-weight: 800;
  letter-spacing: .06em;
  line-height: 1;
  text-shadow: 0 4px 20px rgba(0, 0, 0, .36);
}

.brand span {
  color: var(--gold);
  font-size: 9px;
  font-weight: 700;
  letter-spacing: .16em;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.site-nav button,
.edit-link {
  min-height: 44px;
  padding: 0 14px;
  border: 1px solid transparent;
  border-radius: 2px;
  background: transparent;
  color: rgba(240, 242, 236, .72);
  cursor: pointer;
  font-size: 13px;
  font-weight: 700;
  text-decoration: none;
  transition: color 180ms ease, border-color 180ms ease, background 180ms ease;
}

.site-nav button:hover,
.site-nav button[aria-current="true"] {
  color: var(--text);
  border-color: rgba(240, 242, 236, .22);
  background: rgba(240, 242, 236, .07);
}

.header-actions {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 10px;
}

.contact-button {
  min-height: 44px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0;
  border: 0;
  background: transparent;
  cursor: pointer;
  font-size: 12px;
}

.contact-button span {
  color: var(--muted);
}

.contact-button strong {
  color: var(--text);
  font-weight: 700;
  letter-spacing: .04em;
}

.edit-link {
  display: inline-flex;
  align-items: center;
  border-color: var(--gold);
  background: var(--gold);
  color: var(--ink);
}

.hero {
  position: relative;
  min-height: 100svh;
  height: max(720px, 100svh);
  overflow: hidden;
  background: var(--moss);
}

.ambient-video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(8, 11, 9, .84) 0%, rgba(8, 11, 9, .28) 56%, rgba(8, 11, 9, .36) 100%),
    linear-gradient(0deg, rgba(8, 11, 9, .66), transparent 48%);
}

.hero-content {
  position: absolute;
  z-index: 2;
  left: var(--page-pad);
  bottom: clamp(100px, 15vh, 170px);
  width: min(760px, 66vw);
}

.hero-kicker,
.section-index,
.course-intro > p:first-child {
  margin: 0 0 24px;
  color: var(--gold);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .13em;
}

.hero h1 {
  max-width: 780px;
  margin: 0;
  font-size: clamp(26px, 3.55vw, 50px);
  font-weight: 800;
  line-height: 1.03;
  letter-spacing: -.055em;
  text-wrap: pretty;
  text-shadow: 0 16px 48px rgba(0, 0, 0, .35);
}

.hero-description {
  max-width: 610px;
  margin: 28px 0 0;
  color: rgba(240, 242, 236, .8);
  font-size: clamp(17px, 1.25vw, 21px);
  line-height: 1.75;
  text-wrap: pretty;
}

.primary-action {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  gap: 22px;
  margin-top: 34px;
  padding: 0 0 8px;
  border: 0;
  border-bottom: 1px solid currentColor;
  background: transparent;
  color: var(--text);
  cursor: pointer;
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  transition: gap 220ms var(--ease), color 220ms ease;
}

.primary-action:hover {
  gap: 32px;
  color: var(--gold);
}

.course-intro .primary-action {
  position: relative;
  isolation: isolate;
  min-height: 54px;
  gap: 18px;
  padding: 0 18px 0 22px;
  border: 1px solid rgba(203, 164, 95, .82);
  border-radius: 999px;
  background: rgba(203, 164, 95, .12);
  color: var(--gold);
  font-size: 15px;
  letter-spacing: .04em;
  backdrop-filter: blur(10px);
  box-shadow: 0 12px 32px rgba(0, 0, 0, .18);
  transition: gap 220ms var(--ease), color 220ms ease, background-color 220ms ease, transform 220ms var(--ease), box-shadow 220ms ease;
}

.course-intro .primary-action::before {
  content: "";
  position: absolute;
  z-index: 0;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(110deg, transparent 18%, rgba(255, 237, 177, .08) 34%, rgba(255, 246, 211, .9) 49%, rgba(255, 220, 130, .18) 61%, transparent 78%);
  background-position: 160% 0;
  background-repeat: no-repeat;
  background-size: 280% 100%;
  clip-path: inset(0 round 999px);
  animation: course-cta-reflection 3.8s ease-in-out infinite;
  pointer-events: none;
}

.course-intro .primary-action span {
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border: 1px solid currentColor;
  border-radius: 50%;
}

.course-intro .primary-action:hover {
  gap: 24px;
  background: var(--gold);
  color: var(--ink);
  transform: translateY(-2px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, .28);
}

.course-intro .primary-action:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 4px;
}

.course-cta-sparkle {
  position: absolute;
  z-index: 2;
  top: var(--spark-top-0);
  left: var(--spark-left-0);
  color: #fff2bd;
  font-size: 13px;
  font-style: normal;
  line-height: 1;
  text-shadow: 0 0 5px #fff8db, 0 0 12px #ffd976, 0 0 24px rgba(203, 164, 95, .98);
  filter: drop-shadow(0 0 6px rgba(255, 244, 201, .95)) drop-shadow(0 0 14px rgba(203, 164, 95, .92));
  animation: course-cta-sparkle-random var(--spark-duration, 5.6s) ease-in-out infinite;
  pointer-events: none;
}

.course-cta-sparkle--one {
  --spark-duration: 5.3s;
  --spark-left-0: 12%; --spark-top-0: 24%;
  --spark-left-1: 74%; --spark-top-1: 18%;
  --spark-left-2: 39%; --spark-top-2: 63%;
  --spark-left-3: 87%; --spark-top-3: 46%;
}

.course-cta-sparkle--two {
  font-size: 11px;
  --spark-duration: 6.15s;
  --spark-left-0: 83%; --spark-top-0: 62%;
  --spark-left-1: 27%; --spark-top-1: 16%;
  --spark-left-2: 61%; --spark-top-2: 54%;
  --spark-left-3: 10%; --spark-top-3: 69%;
  animation-delay: -1.7s;
}

.course-cta-sparkle--three {
  font-size: 10px;
  --spark-duration: 7.05s;
  --spark-left-0: 48%; --spark-top-0: 17%;
  --spark-left-1: 14%; --spark-top-1: 51%;
  --spark-left-2: 86%; --spark-top-2: 27%;
  --spark-left-3: 54%; --spark-top-3: 70%;
  animation-delay: -3.2s;
}

@keyframes course-cta-reflection {
  0%, 54% { background-position: 160% 0; opacity: 0; }
  62% { opacity: .9; }
  82%, 100% { background-position: -60% 0; opacity: 0; }
}

@keyframes course-cta-sparkle-random {
  0%, 4% { top: var(--spark-top-0); left: var(--spark-left-0); opacity: 0; transform: translate(-50%, -50%) scale(.55); }
  8% { top: var(--spark-top-0); left: var(--spark-left-0); opacity: 1; transform: translate(-50%, -50%) scale(1.3); }
  14% { top: var(--spark-top-0); left: var(--spark-left-0); opacity: 0; transform: translate(-50%, -50%) scale(.7); }
  15%, 29% { top: var(--spark-top-1); left: var(--spark-left-1); opacity: 0; transform: translate(-50%, -50%) scale(.55); }
  33% { top: var(--spark-top-1); left: var(--spark-left-1); opacity: 1; transform: translate(-50%, -50%) scale(1.25); }
  39% { top: var(--spark-top-1); left: var(--spark-left-1); opacity: 0; transform: translate(-50%, -50%) scale(.7); }
  40%, 54% { top: var(--spark-top-2); left: var(--spark-left-2); opacity: 0; transform: translate(-50%, -50%) scale(.55); }
  58% { top: var(--spark-top-2); left: var(--spark-left-2); opacity: 1; transform: translate(-50%, -50%) scale(1.35); }
  64% { top: var(--spark-top-2); left: var(--spark-left-2); opacity: 0; transform: translate(-50%, -50%) scale(.7); }
  65%, 79% { top: var(--spark-top-3); left: var(--spark-left-3); opacity: 0; transform: translate(-50%, -50%) scale(.55); }
  83% { top: var(--spark-top-3); left: var(--spark-left-3); opacity: 1; transform: translate(-50%, -50%) scale(1.28); }
  89% { top: var(--spark-top-3); left: var(--spark-left-3); opacity: 0; transform: translate(-50%, -50%) scale(.7); }
  90%, 100% { top: var(--spark-top-0); left: var(--spark-left-0); opacity: 0; transform: translate(-50%, -50%) scale(.55); }
}

@media (prefers-reduced-motion: reduce) {
  .course-intro .primary-action::before,
  .course-cta-sparkle {
    animation: none;
  }
}

.hero-facts {
  position: absolute;
  z-index: 2;
  right: var(--page-pad);
  bottom: clamp(52px, 8vh, 90px);
  display: grid;
  grid-template-columns: repeat(3, minmax(100px, 1fr));
  border-top: 1px solid rgba(240, 242, 236, .28);
}

.hero-facts div {
  min-width: 126px;
  display: grid;
  gap: 4px;
  padding: 18px 20px 0 0;
}

.hero-facts strong {
  font-size: clamp(24px, 2.2vw, 36px);
  font-weight: 800;
}

.hero-facts span {
  color: var(--muted);
  font-size: 11px;
}

.section-light {
  background: var(--paper);
  color: var(--text-dark);
}

.section-dark {
  background: var(--ink);
  color: var(--text);
}

.featured,
.portfolio-section,
.course-library {
  padding: clamp(96px, 12vw, 170px) var(--page-pad);
}

.section-heading {
  max-width: 970px;
  margin-bottom: clamp(48px, 6vw, 86px);
}

.split-heading {
  max-width: none;
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(260px, .55fr);
  gap: clamp(36px, 8vw, 140px);
  align-items: end;
}

.section-heading h2 {
  max-width: 980px;
  margin: 0;
  font-size: clamp(43px, 5.8vw, 82px);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -.045em;
  text-wrap: pretty;
}

.section-heading > p:last-child,
.split-heading > p {
  max-width: 560px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
  text-wrap: pretty;
}

.section-light .section-index {
  color: #84611f;
}

.section-light .section-heading > p:last-child,
.section-light .split-heading > p {
  color: var(--muted-dark);
}

.featured-grid {
  display: grid;
  grid-template-columns: 1.15fr .85fr;
  gap: 14px;
}

.featured-card {
  position: relative;
  min-height: clamp(480px, 62vw, 760px);
  overflow: hidden;
  border: 0;
  border-radius: 2px;
  background: var(--moss);
  color: var(--text);
  cursor: pointer;
  text-align: left;
}

.featured-card img,
.media-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 800ms var(--ease), filter 500ms ease;
}

.featured-card img {
  position: absolute;
  inset: 0;
}

.featured-card::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(0deg, rgba(8, 11, 9, .88), transparent 58%);
}

.featured-card[data-kind="image"]:hover img,
.featured-card[data-kind="image"]:focus-visible img,
.media-card[data-kind="image"]:hover img,
.media-card[data-kind="image"]:focus-visible img {
  transform: scale(1.025);
  filter: saturate(1.06) contrast(1.02);
}

.featured-card-content {
  position: absolute;
  z-index: 1;
  inset: auto 30px 30px;
  display: grid;
  gap: 8px;
}

.featured-card-content span {
  color: var(--gold);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .12em;
}

.featured-card-content strong {
  font-size: clamp(37px, 4.6vw, 72px);
  font-weight: 800;
  letter-spacing: -.04em;
}

.featured-card-content small {
  color: var(--muted);
  font-size: 13px;
}

.collection {
  margin-top: clamp(58px, 8vw, 108px);
}

.collection:first-child {
  margin-top: 0;
}

.collection-header {
  min-height: 62px;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 28px;
  margin-bottom: 22px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
}

.section-light .collection-header {
  border-color: var(--line-dark);
}

.collection-title {
  display: flex;
  align-items: baseline;
  gap: 18px;
}

.collection-title h3 {
  margin: 0;
  font-size: clamp(24px, 2.6vw, 38px);
  font-weight: 800;
  letter-spacing: -.025em;
}

.collection-title span {
  color: var(--muted);
  font-size: 11px;
}

.section-light .collection-title span {
  color: var(--muted-dark);
}

.rail-controls {
  display: flex;
  align-items: center;
  gap: 10px;
}

.rail-progress {
  min-width: 52px;
  text-align: center;
  color: var(--muted);
  font-size: 11px;
  font-variant-numeric: tabular-nums;
}

.section-light .rail-progress {
  color: var(--muted-dark);
}

.rail-button,
.icon-button {
  min-width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: transparent;
  cursor: pointer;
  transition: color 180ms ease, background 180ms ease, border-color 180ms ease, opacity 180ms ease;
}

.section-light .rail-button {
  border-color: var(--line-dark);
}

.rail-button:hover:not(:disabled) {
  border-color: var(--gold);
  background: var(--gold);
  color: var(--ink);
}

.rail-button:disabled {
  cursor: default;
  opacity: .28;
}

.media-rail {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: calc((100% - 32px) / 3);
  gap: 16px;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x mandatory;
  scrollbar-width: none;
}

.media-rail::-webkit-scrollbar {
  display: none;
}

.media-card {
  min-width: 0;
  padding: 0;
  border: 0;
  border-radius: 2px;
  background: transparent;
  color: inherit;
  cursor: pointer;
  scroll-snap-align: start;
  text-align: left;
}

.media-card-visual {
  position: relative;
  width: 100%;
  display: block;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background: var(--moss);
}

.media-card-visual::after {
  content: "播放";
  position: absolute;
  right: 14px;
  bottom: 14px;
  min-width: 52px;
  height: 30px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(240, 242, 236, .55);
  border-radius: 2px;
  background: rgba(8, 11, 9, .56);
  color: var(--text);
  font-size: 11px;
  font-weight: 700;
  backdrop-filter: blur(10px);
  opacity: 0;
  transform: translateY(5px);
  transition: opacity 180ms ease, transform 220ms var(--ease);
}

.media-card[data-kind="image"] .media-card-visual::after {
  content: "查看";
}

.media-card:hover .media-card-visual::after,
.media-card:focus-visible .media-card-visual::after {
  opacity: 1;
  transform: none;
}

.media-card-copy {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 16px 0 4px;
}

.media-card-copy strong {
  overflow: hidden;
  font-size: 17px;
  font-weight: 700;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.media-card-copy span {
  flex: none;
  color: var(--muted);
  font-size: 11px;
  font-variant-numeric: tabular-nums;
}

.section-light .media-card-copy span {
  color: var(--muted-dark);
}

.cinematic-break {
  position: relative;
  height: min(76vw, 820px);
  min-height: 560px;
  overflow: hidden;
  background: var(--moss);
}

.cinematic-break--tall {
  height: min(88vw, 940px);
}

.cinematic-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(8, 11, 9, .68), transparent 70%);
}

.cinematic-overlay--forest {
  background: linear-gradient(270deg, rgba(8, 11, 9, .7), transparent 70%);
}

.cinematic-copy {
  position: absolute;
  z-index: 1;
  left: var(--page-pad);
  bottom: clamp(40px, 7vw, 100px);
  display: grid;
  gap: 12px;
}

.cinematic-copy--right {
  right: var(--page-pad);
  left: auto;
  text-align: right;
}

.cinematic-copy span {
  color: var(--gold);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: .18em;
}

.cinematic-copy strong {
  font-size: clamp(42px, 7vw, 104px);
  font-weight: 800;
  letter-spacing: -.045em;
}

.project-collections .collection:first-child {
  margin-top: 0;
}

.course-hero {
  position: relative;
  min-height: max(760px, 94svh);
  overflow: hidden;
  background: var(--moss);
}

.course-overlay {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(8, 11, 9, .88) 0%, rgba(8, 11, 9, .28) 62%, rgba(8, 11, 9, .52) 100%),
    linear-gradient(0deg, rgba(8, 11, 9, .7), transparent 50%);
}

.course-intro {
  position: absolute;
  z-index: 1;
  left: var(--page-pad);
  bottom: clamp(90px, 13vh, 150px);
  width: min(820px, 64vw);
}

.course-intro h2 {
  margin: 0;
  font-size: clamp(23px, 3.2vw, 45px);
  font-weight: 800;
  line-height: 1.06;
  letter-spacing: -.05em;
  text-wrap: pretty;
}

.course-description {
  max-width: 700px;
  margin: 26px 0 0;
  color: rgba(240, 242, 236, .78);
  font-size: 18px;
  line-height: 1.8;
  text-wrap: pretty;
}

.course-facts {
  position: absolute;
  z-index: 1;
  right: var(--page-pad);
  bottom: clamp(74px, 11vh, 130px);
  width: min(420px, 31vw);
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid rgba(240, 242, 236, .28);
}

.course-facts div {
  display: grid;
  gap: 6px;
  padding: 18px 8px 0 0;
}

.course-facts strong {
  font-size: clamp(20px, 2.1vw, 32px);
  font-weight: 800;
}

.course-facts span {
  color: var(--muted);
  font-size: 11px;
}

.site-footer {
  min-height: 68svh;
  display: grid;
  place-content: center;
  justify-items: center;
  gap: 28px;
  padding: 90px var(--page-pad) 50px;
  background: var(--gold);
  color: var(--ink);
  text-align: center;
}

.site-footer > p {
  margin: 0;
  font-size: clamp(22px, 2.6vw, 38px);
  font-weight: 700;
}

.site-footer button {
  display: grid;
  justify-items: center;
  gap: 4px;
  padding: 0;
  border: 0;
  background: transparent;
  cursor: pointer;
}

.site-footer button span {
  font-size: clamp(22px, 2.1vw, 32px);
  font-weight: 800;
}

.site-footer button strong {
  font-size: clamp(56px, 10vw, 150px);
  font-weight: 800;
  letter-spacing: -.055em;
}

.site-footer button b {
  margin-top: 16px;
  border-bottom: 1px solid currentColor;
  font-size: clamp(16px, 1.35vw, 21px);
  font-weight: 800;
}

.site-footer small {
  align-self: end;
  margin-top: 70px;
  font-size: 11px;
}

.site-footer .site-filing {
  display: block;
  margin-top: 10px;
}

.site-footer .site-filing a {
  color: inherit;
  text-decoration: none;
  opacity: .72;
}

.site-footer .site-filing a:hover,
.site-footer .site-filing a:focus-visible {
  color: var(--gold);
  opacity: 1;
}

.viewer {
  position: fixed;
  z-index: 400;
  inset: 0;
  display: grid;
  place-items: center;
  padding: clamp(12px, 4vw, 66px);
}

.viewer-backdrop {
  position: absolute;
  inset: 0;
  border: 0;
  background: rgba(3, 5, 3, .88);
  backdrop-filter: blur(18px);
  cursor: zoom-out;
}

.viewer-shell {
  position: relative;
  width: min(1320px, 100%);
  max-height: calc(100svh - 30px);
  overflow: auto;
  border: 1px solid rgba(240, 242, 236, .2);
  border-radius: 2px;
  background: var(--ink);
  box-shadow: 0 32px 110px rgba(0, 0, 0, .65);
  animation: viewer-enter 420ms var(--ease) both;
}

@keyframes viewer-enter {
  from { opacity: 0; transform: translateY(20px) scale(.988); }
  to { opacity: 1; transform: none; }
}

.viewer-header {
  min-height: 84px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  padding: 18px 24px;
  border-bottom: 1px solid var(--line);
}

.viewer-header > div {
  display: flex;
  align-items: baseline;
  gap: 18px;
}

.viewer-header > div > span {
  color: var(--gold);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: .12em;
}

.viewer-header h2 {
  margin: 0;
  font-size: clamp(24px, 3vw, 42px);
  font-weight: 800;
  letter-spacing: -.025em;
}

.icon-button {
  width: auto;
  padding: 0 0 0 12px;
  border: 0;
  border-radius: 0;
  font-size: 12px;
  font-weight: 700;
}

.icon-button span {
  width: 40px;
  height: 40px;
  display: inline-grid;
  margin-left: 10px;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 50%;
  font-size: 20px;
  font-weight: 400;
  transition: transform 220ms var(--ease), background 180ms ease, color 180ms ease;
}

.icon-button:hover span {
  background: var(--text);
  color: var(--ink);
  transform: rotate(90deg);
}

.viewer-media {
  position: relative;
  min-height: 280px;
  display: grid;
  place-items: center;
  background: #020302;
}

.viewer-media video,
.viewer-media img {
  width: 100%;
  max-height: min(74svh, 840px);
  object-fit: contain;
}

.viewer-status {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  margin: 0;
  background: #020302;
  color: var(--muted);
  font-size: 13px;
}

.viewer-media[data-state="ready"] .viewer-status {
  display: none;
}

.viewer-media[data-state="error"] .viewer-status {
  color: var(--gold);
}

.viewer-footer {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 34px;
  padding: 24px;
}

.viewer-footer > p {
  max-width: 760px;
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
  text-wrap: pretty;
}

.viewer-footer dl {
  display: flex;
  gap: 22px;
  margin: 0;
}

.viewer-footer dl div {
  display: grid;
  gap: 5px;
}

.viewer-footer dt {
  color: var(--muted);
  font-size: 9px;
  letter-spacing: .1em;
}

.viewer-footer dd {
  margin: 0;
  font-size: 12px;
  font-variant-numeric: tabular-nums;
}

.toast {
  position: fixed;
  z-index: 500;
  right: 24px;
  bottom: 24px;
  padding: 14px 18px;
  border: 1px solid rgba(240, 242, 236, .2);
  border-radius: 2px;
  background: rgba(8, 11, 9, .92);
  color: var(--text);
  box-shadow: 0 16px 54px rgba(0, 0, 0, .35);
  font-size: 13px;
}

.page-loading {
  position: fixed;
  z-index: 350;
  inset: 0;
  display: grid;
  place-content: center;
  justify-items: center;
  gap: 18px;
  background: var(--ink);
  transition: opacity 350ms ease, visibility 350ms ease;
}

.page-loading.is-done {
  opacity: 0;
  visibility: hidden;
}

.page-loading span {
  width: 40px;
  height: 40px;
  border: 2px solid rgba(240, 242, 236, .16);
  border-top-color: var(--gold);
  border-radius: 50%;
  animation: loading-spin .8s linear infinite;
}

@keyframes loading-spin {
  to { transform: rotate(360deg); }
}

.page-loading p {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

@media (max-width: 1050px) {
  .site-header {
    grid-template-columns: 1fr auto;
  }

  .site-nav {
    display: none;
  }

  .hero-content,
  .course-intro {
    width: min(760px, 78vw);
  }

  .hero-facts,
  .course-facts {
    right: var(--page-pad);
    width: auto;
  }

  .hero-facts {
    bottom: 36px;
  }

  .course-facts {
    bottom: 46px;
  }

  .media-rail {
    grid-auto-columns: calc((100% - 16px) / 2);
  }
}

@media (max-width: 720px) {
  :root {
    --header-height: 70px;
    --page-pad: 18px;
  }

  .site-header {
    gap: 10px;
  }

  .brand {
    gap: 9px;
  }

  .brand strong {
    font-size: 25px;
  }

  .brand span,
  .contact-button span {
    display: none;
  }

  .contact-button strong {
    font-size: 11px;
  }

  .edit-link {
    width: 44px;
    overflow: hidden;
    justify-content: center;
    padding: 0;
    font-size: 0;
  }

  .edit-link::after {
    content: "编辑";
    font-size: 11px;
  }

  .hero {
    min-height: 760px;
  }

  .hero-content {
    bottom: 190px;
    width: calc(100% - 36px);
  }

  .hero h1 {
    max-width: 560px;
    font-size: clamp(23px, 7.55vw, 34px);
    line-height: 1.05;
  }

  .hero-description {
    margin-top: 20px;
    font-size: 16px;
  }

  .hero-facts {
    right: 18px;
    left: 18px;
    bottom: 34px;
  }

  .hero-facts div {
    min-width: 0;
  }

  .split-heading {
    display: block;
  }

  .section-heading h2 {
    font-size: clamp(40px, 12vw, 58px);
  }

  .featured-grid {
    grid-template-columns: 1fr;
  }

  .featured-card {
    min-height: 58vh;
  }

  .media-rail {
    grid-auto-columns: 84%;
  }

  .collection-header {
    align-items: center;
  }

  .collection-title {
    display: grid;
    gap: 4px;
  }

  .rail-progress {
    display: none;
  }

  .cinematic-break,
  .cinematic-break--tall {
    height: 72svh;
    min-height: 520px;
  }

  .course-hero {
    min-height: 820px;
  }

  .course-intro {
    top: 140px;
    bottom: auto;
    width: calc(100% - 36px);
  }

  .course-intro h2 {
    font-size: clamp(21px, 6.22vw, 30px);
  }

  .course-description {
    font-size: 16px;
  }

  .course-facts {
    right: 18px;
    bottom: 42px;
    left: 18px;
  }

  .site-footer {
    min-height: 62svh;
  }

  .site-footer button strong {
    font-size: clamp(48px, 17vw, 82px);
  }

  .viewer {
    padding: 8px;
  }

  .viewer-shell {
    max-height: calc(100svh - 16px);
  }

  .viewer-header {
    padding: 14px 16px;
  }

  .viewer-header > div {
    display: grid;
    gap: 4px;
  }

  .icon-button {
    font-size: 0;
  }

  .icon-button span {
    margin: 0;
  }

  .viewer-footer {
    grid-template-columns: 1fr;
    padding: 18px 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }

  .media-card img,
  .featured-card img {
    transform: none !important;
  }
}

/* v2 — focused video presentation and clearer navigation */
.site-nav {
  gap: 10px;
}

.site-nav button {
  min-height: 48px;
  padding-inline: 18px;
  font-size: 16px;
  letter-spacing: .01em;
}

.section-index,
.course-intro > p:first-child {
  width: max-content;
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  margin-bottom: 28px;
  padding: 0 18px;
  border: 1px solid rgba(203, 164, 95, .46);
  border-radius: 2px;
  background: rgba(8, 11, 9, .88);
  color: var(--gold) !important;
  font-size: 16px;
  letter-spacing: .035em;
}

.section-light .section-index {
  border-color: rgba(8, 11, 9, .18);
  background: var(--ink);
}

.featured-grid {
  display: block;
}

.featured-grid .collection {
  margin-top: 0;
}

.collection-header {
  min-height: 72px;
  align-items: center;
  margin-bottom: 26px;
  padding-bottom: 20px;
}

.collection-title {
  align-items: center;
  gap: 16px;
}

.collection-title h3 {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  margin: 0;
  padding: 0 18px;
  border: 1px solid rgba(203, 164, 95, .42);
  border-radius: 2px;
  background: var(--ink-soft);
  color: var(--gold);
  font-size: clamp(17px, 1.35vw, 20px);
  font-weight: 800;
  letter-spacing: .015em;
}

.section-light .collection-title h3 {
  background: var(--ink);
  color: var(--gold);
}

.collection-title span {
  font-size: 13px;
}

.collection--video .media-rail,
.featured-rail {
  grid-auto-columns: 100%;
  gap: 24px;
}

.collection--video .media-card-visual,
.featured-card,
.featured-card-visual {
  aspect-ratio: 16 / 9;
}

.collection--video .media-card-visual {
  max-height: min(78svh, 940px);
}

.featured-card {
  min-height: 0;
  display: block;
  scroll-snap-align: start;
}

.featured-card-visual {
  position: absolute;
  inset: 0;
  display: block;
  overflow: hidden;
}

.media-card-visual > img,
.media-card-visual > video,
.featured-card-visual > img,
.featured-card-visual > video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-preview {
  z-index: 1;
  opacity: 0;
  background: var(--moss);
  transition: opacity 420ms ease;
}

.media-preview.is-playing {
  opacity: 1;
}

.preview-label {
  position: absolute;
  z-index: 3;
  top: 18px;
  right: 18px;
  min-height: 34px;
  display: inline-flex;
  align-items: center;
  padding: 0 12px;
  border: 1px solid rgba(240, 242, 236, .38);
  border-radius: 2px;
  background: rgba(8, 11, 9, .64);
  color: rgba(240, 242, 236, .9);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .04em;
  pointer-events: none;
  backdrop-filter: blur(10px);
}

.featured-card::after {
  z-index: 2;
}

.featured-card-content {
  z-index: 3;
}

.collection--video .media-card-copy {
  padding-top: 20px;
}

.collection--video .media-card-copy strong {
  font-size: clamp(22px, 2vw, 32px);
}

.rail-controls {
  min-height: 92px;
  display: grid;
  grid-template-columns: minmax(150px, 1fr) minmax(240px, 420px) minmax(150px, 1fr);
  align-items: center;
  gap: clamp(18px, 4vw, 56px);
  margin-top: 24px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.section-light .rail-controls {
  border-color: var(--line-dark);
}

.rail-button {
  width: max-content;
  min-width: 156px;
  height: 52px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  padding: 0 18px;
  border-radius: 2px;
  font-size: 14px;
  font-weight: 700;
}

.rail-button--previous {
  justify-self: start;
}

.rail-button--next {
  justify-self: end;
}

.rail-button span {
  color: var(--gold);
  font-size: 18px;
}

.rail-button:hover:not(:disabled) span {
  color: var(--ink);
}

.rail-status {
  min-width: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 9px 16px;
}

.rail-current-title {
  overflow: hidden;
  font-size: 14px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.rail-progress {
  min-width: 58px;
  color: var(--gold);
  font-size: 13px;
  font-weight: 800;
}

.rail-progress-track {
  grid-column: 1 / -1;
  height: 3px;
  overflow: hidden;
  background: var(--line);
}

.section-light .rail-progress-track {
  background: var(--line-dark);
}

.rail-progress-track i {
  display: block;
  width: 100%;
  height: 100%;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 320ms var(--ease);
}

.rail-hint {
  grid-column: 1 / -1;
  color: var(--muted);
  font-size: 11px;
}

.section-light .rail-hint {
  color: var(--muted-dark);
}

.hero-video,
.cinematic-break .ambient-video,
.course-hero .ambient-video {
  object-fit: contain;
  background: #050705;
}

.cinematic-break,
.cinematic-break--tall {
  height: auto;
  min-height: 0;
  aspect-ratio: 16 / 9;
  background: #050705;
}

@media (max-width: 1050px) {
  .collection--video .media-rail,
  .featured-rail {
    grid-auto-columns: 100%;
  }

  .rail-controls {
    grid-template-columns: auto minmax(180px, 1fr) auto;
    gap: 18px;
  }

  .rail-button {
    min-width: 52px;
  }

  .rail-button strong {
    display: none;
  }
}

@media (max-width: 720px) {
  .section-index,
  .course-intro > p:first-child {
    min-height: 44px;
    padding-inline: 15px;
    font-size: 15px;
  }

  .collection-header {
    margin-bottom: 18px;
  }

  .collection-title {
    display: flex;
    gap: 12px;
  }

  .collection-title h3 {
    min-height: 44px;
    padding-inline: 14px;
    font-size: 16px;
  }

  .collection--video .media-rail,
  .featured-rail {
    grid-auto-columns: 100%;
  }

  .collection--video .media-card-visual,
  .featured-card,
  .featured-card-visual {
    aspect-ratio: 16 / 10;
  }

  .featured-card-content {
    inset: auto 20px 20px;
  }

  .featured-card-content strong {
    font-size: clamp(34px, 11vw, 52px);
  }

  .preview-label {
    top: 10px;
    right: 10px;
    min-height: 30px;
    font-size: 10px;
  }

  .rail-controls {
    min-height: 84px;
    grid-template-columns: 52px minmax(0, 1fr) 52px;
    gap: 12px;
    margin-top: 18px;
    padding-top: 18px;
  }

  .rail-button {
    min-width: 52px;
    width: 52px;
    height: 48px;
    padding: 0;
  }

  .rail-status {
    gap: 7px 10px;
  }

  .rail-current-title {
    font-size: 12px;
  }

  .rail-progress {
    display: block;
    min-width: 48px;
    font-size: 11px;
  }

  .rail-hint {
    display: none;
  }

  .cinematic-break,
  .cinematic-break--tall {
    height: auto;
    min-height: 0;
    aspect-ratio: 16 / 9;
  }

  .cinematic-copy {
    bottom: 24px;
  }

  .cinematic-copy strong {
    font-size: clamp(34px, 11vw, 54px);
  }

  .course-hero .ambient-video {
    object-position: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  .media-preview {
    display: none;
  }
}

/* v3 — independent chapter routes */
body {
  animation: page-enter 420ms var(--ease) both;
}

html.is-leaving body {
  opacity: 0;
  transition: opacity 220ms ease;
}

@keyframes page-enter {
  from { opacity: 0; }
  to { opacity: 1; }
}

.chapter-header {
  position: absolute;
  border-bottom: 0;
  background: linear-gradient(180deg, rgba(8, 11, 9, .72), rgba(8, 11, 9, 0));
  backdrop-filter: none;
}

.chapter-header.is-solid {
  border-color: transparent;
  background: linear-gradient(180deg, rgba(8, 11, 9, .96), rgba(8, 11, 9, .72) 66%, rgba(8, 11, 9, 0));
}

.chapter-header .contact-button {
  justify-self: end;
}

.chapter-nav {
  position: fixed;
  z-index: 420;
  top: 14px;
  left: 50%;
  transform: translateX(-50%);
  min-height: 58px;
  display: flex;
  gap: 2px;
  padding: 6px 10px;
  border: 1px solid rgb(126, 132, 127);
  border-radius: 999px;
  background: rgba(8, 11, 9, .2);
  box-shadow: 0 18px 44px rgba(0, 0, 0, .2);
  backdrop-filter: blur(32px) saturate(1.12);
  -webkit-backdrop-filter: blur(32px) saturate(1.12);
  transition: opacity 260ms ease, transform 320ms var(--ease);
}

.chapter-nav a {
  position: relative;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 18px;
  border-radius: 999px;
  color: rgba(240, 242, 236, .62);
  font-size: 16px;
  font-weight: 650;
  letter-spacing: .025em;
  text-decoration: none;
  transition: color 180ms ease, background 180ms ease;
}

.chapter-nav a:hover,
.chapter-nav a:focus-visible {
  color: var(--text);
  background: rgba(240, 242, 236, .06);
}

.chapter-nav a[aria-current="page"] {
  color: var(--text);
  font-weight: 800;
}

.chapter-nav a[aria-current="page"]::after {
  content: "";
  position: absolute;
  right: 19px;
  bottom: 5px;
  left: 19px;
  height: 2px;
  border-radius: 50%;
  background: var(--gold);
  transform: rotate(-2deg);
  box-shadow: 5px 1px 0 -1px var(--gold);
}

.chapter-directory {
  padding: clamp(96px, 11vw, 160px) var(--page-pad) clamp(110px, 13vw, 190px);
}

.chapter-card-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.chapter-card {
  position: relative;
  min-height: clamp(420px, 42vw, 650px);
  overflow: hidden;
  border-radius: 2px;
  background: var(--moss);
  color: var(--text);
  text-decoration: none;
}

.chapter-card::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(0deg, rgba(8, 11, 9, .92), rgba(8, 11, 9, .05) 66%);
}

.chapter-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 700ms var(--ease), filter 450ms ease;
}

.chapter-card:hover img,
.chapter-card:focus-visible img {
  transform: scale(1.035);
  filter: saturate(1.08) contrast(1.02);
}

.chapter-card > span {
  position: absolute;
  z-index: 1;
  right: 24px;
  bottom: 26px;
  left: 24px;
  display: grid;
  gap: 9px;
}

.chapter-card small {
  color: var(--gold);
  font-size: 10px;
  font-weight: 800;
  letter-spacing: .13em;
}

.chapter-card strong {
  font-size: clamp(30px, 3.4vw, 56px);
  font-weight: 800;
  letter-spacing: -.035em;
}

.chapter-card b {
  width: max-content;
  padding-bottom: 5px;
  border-bottom: 1px solid rgba(240, 242, 236, .6);
  font-size: 12px;
  transition: color 180ms ease, border-color 180ms ease;
}

.chapter-card:hover b {
  border-color: var(--gold);
  color: var(--gold);
}

.chapter-content {
  min-height: 100svh;
  padding-top: calc(var(--header-height) + clamp(72px, 8vw, 128px));
}

.chapter-breadcrumb {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: clamp(48px, 7vw, 92px);
  color: var(--muted);
  font-size: 12px;
}

.chapter-breadcrumb a {
  color: inherit;
  text-decoration: none;
}

.chapter-breadcrumb a:hover {
  color: var(--gold);
}

.chapter-breadcrumb strong {
  color: var(--gold);
  font-weight: 700;
}

.chapter-page--light .chapter-breadcrumb {
  color: var(--muted-dark);
}

.chapter-heading h1 {
  max-width: 980px;
  margin: 0;
  font-size: clamp(43px, 5.8vw, 82px);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -.045em;
  text-wrap: pretty;
}

.chapter-heading > p:last-child,
.chapter-heading.split-heading > p {
  max-width: 560px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
  text-wrap: pretty;
}

.section-light .chapter-heading > p:last-child,
.section-light .chapter-heading.split-heading > p {
  color: var(--muted-dark);
}

.course-intro h1 {
  margin: 0;
  font-size: clamp(23px, 3.2vw, 45px);
  font-weight: 800;
  line-height: 1.06;
  letter-spacing: -.05em;
  text-wrap: pretty;
}

@media (max-width: 1050px) {
  :root {
    --header-height: 122px;
  }

  .chapter-header {
    height: var(--header-height);
    grid-template-columns: 1fr auto;
    grid-template-rows: 48px 58px;
    align-content: center;
    gap: 2px 16px;
  }

  .chapter-header .brand,
  .chapter-header .contact-button {
    grid-row: 1;
  }

  .chapter-nav {
    top: 60px;
    grid-row: 2;
    grid-column: 1 / -1;
    justify-self: center;
  }

  .chapter-card-grid {
    grid-template-columns: 1fr 1fr;
  }

  .chapter-card:first-child {
    grid-column: 1 / -1;
    min-height: 56vw;
  }
}

@media (max-width: 720px) {
  :root {
    --header-height: 116px;
  }

  .chapter-header {
    padding-inline: 14px;
  }

  .chapter-nav {
    top: 58px;
    width: 100%;
    min-height: 52px;
    justify-content: center;
    padding: 4px;
  }

  .chapter-nav a {
    min-width: 0;
    min-height: 42px;
    flex: 1 1 auto;
    padding: 0 7px;
    font-size: 12px;
  }

  .chapter-nav a[aria-current="page"]::after {
    right: 12px;
    bottom: 4px;
    left: 12px;
  }

  .chapter-header .contact-button strong {
    font-size: 11px;
  }

  .chapter-card-grid {
    grid-template-columns: 1fr;
  }

  .chapter-card,
  .chapter-card:first-child {
    grid-column: auto;
    min-height: 118vw;
  }

  .chapter-content {
    padding-top: calc(var(--header-height) + 54px);
  }

  .chapter-heading h1 {
    font-size: clamp(40px, 12vw, 58px);
  }

  .course-intro h1 {
    font-size: clamp(21px, 6.22vw, 30px);
  }
}

@media (prefers-reduced-motion: reduce) {
  body {
    animation: none;
  }

  html.is-leaving body {
    opacity: 1;
    transform: none;
  }
}

/* v3.1 — controls above media and alternating slide surfaces */
.collection--video .media-card {
  padding: clamp(14px, 1.8vw, 28px);
  transition: background-color 360ms ease, color 360ms ease;
}

.collection--video .media-card:nth-child(odd) {
  background: #080b09;
  color: var(--text);
}

.collection--video .media-card:nth-child(even) {
  background: #252925;
  color: var(--text);
}

.collection--video .media-card-copy {
  padding: 0 0 clamp(16px, 2vw, 24px);
}

.collection--video .media-card-copy span {
  color: rgba(240, 242, 236, .62);
}

.collection .rail-controls {
  margin: 0 0 24px;
  padding: 0 0 22px;
  border-top: 0;
  border-bottom: 1px solid var(--line);
}

.section-light .collection .rail-controls {
  border-bottom-color: var(--line-dark);
}

.chapter-background {
  margin: 0;
  width: 100%;
  height: max(760px, 94svh);
  min-height: 0;
  aspect-ratio: auto;
}

.chapter-background + .chapter-content {
  padding-top: clamp(96px, 11vw, 160px);
}

.page-progress {
  display: none;
}

.section-index,
.course-intro > p:first-child {
  min-height: 0;
  padding: 0;
  border: 0;
  background: transparent;
}

.collection-title h3,
.section-light .collection-title h3 {
  min-height: 0;
  padding: 0;
  border: 0;
  background: transparent;
  color: var(--gold);
}

.collection--video .media-card[data-surface="black"] {
  background: #080b09;
  color: var(--text);
}

.collection--video .media-card[data-surface="gray"] {
  background: #252925;
  color: var(--text);
}

@media (max-width: 720px) {
  .collection--video .media-card {
    padding: 10px;
  }

  .collection .rail-controls {
    margin-bottom: 16px;
    padding-bottom: 16px;
  }

  .chapter-background {
    height: 820px;
    min-height: 820px;
  }
}

/* v3.2 — the complete active video module owns the alternating surface */
.collection--video .collection-stage {
  padding: clamp(16px, 2vw, 30px);
  color: var(--text);
  transition: background-color 420ms var(--ease), color 420ms ease;
}

.collection--video .collection-stage[data-surface="black"] {
  background: #080b09;
}

.collection--video .collection-stage[data-surface="gray"] {
  background: #252925;
}

.collection--video .collection-stage .media-card,
.collection--video .collection-stage .media-card[data-surface="black"],
.collection--video .collection-stage .media-card[data-surface="gray"] {
  padding: 0;
  background: transparent;
  color: inherit;
}

.collection--video .collection-stage .rail-controls {
  margin: 0 0 clamp(18px, 2.3vw, 30px);
  padding: 0 0 clamp(16px, 2vw, 24px);
  border-bottom-color: rgba(240, 242, 236, .2);
}

.collection--video .collection-stage .rail-button {
  border-color: rgba(240, 242, 236, .26);
  color: var(--text);
}

.collection--video .collection-stage .rail-button:hover:not(:disabled) {
  border-color: var(--gold);
  background: var(--gold);
  color: var(--ink);
}

.collection--video .collection-stage .rail-current-title {
  color: var(--text);
}

.collection--video .collection-stage .rail-progress {
  color: var(--gold);
}

.collection--video .collection-stage .rail-progress-track {
  background: rgba(240, 242, 236, .18);
}

.collection--video .collection-stage .rail-hint,
.collection--video .collection-stage .media-card-copy span {
  color: rgba(240, 242, 236, .62);
}

@media (max-width: 720px) {
  .collection--video .collection-stage {
    padding: 10px;
  }
}

/* v3.3 — alternate the full page-width video module, not an inner card */
.collection--video {
  margin-right: calc(var(--page-pad) * -1);
  margin-left: calc(var(--page-pad) * -1);
  padding: clamp(56px, 7vw, 104px) var(--page-pad);
  color: var(--text);
  transition: background-color 420ms var(--ease), color 420ms ease;
}

.collection--video + .collection--video {
  margin-top: 0;
}

.collection--video[data-surface="black"] {
  background: #080b09;
}

.collection--video[data-surface="gray"] {
  background: #252925;
}

.collection--video .collection-stage,
.collection--video .collection-stage[data-surface="black"],
.collection--video .collection-stage[data-surface="gray"] {
  padding: 0;
  background: transparent;
}

.collection--video .collection-header,
.section-light .collection--video .collection-header {
  border-bottom-color: rgba(240, 242, 236, .2);
}

.collection--video .collection-title h3,
.section-light .collection--video .collection-title h3 {
  color: var(--gold);
}

.collection--video .collection-title span,
.section-light .collection--video .collection-title span {
  color: rgba(240, 242, 236, .58);
}

@media (max-width: 720px) {
  .collection--video {
    padding-top: 48px;
    padding-bottom: 48px;
  }

  .collection--video .collection-stage {
    padding: 0;
  }
}

/* v3.4 — chapter hero typography and framed gold labels */
.chapter-hero-copy {
  position: absolute;
  z-index: 2;
  left: var(--page-pad);
  bottom: clamp(70px, 10vh, 124px);
  width: min(900px, 72vw);
}

.chapter-hero-label,
.collection--video .collection-title h3,
.section-light .collection--video .collection-title h3 {
  width: max-content;
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  padding: 0 18px;
  border: 1px solid rgba(203, 164, 95, .5);
  border-radius: 2px;
  background: rgba(8, 11, 9, .68);
  color: var(--gold);
  font-size: clamp(15px, 1.3vw, 19px);
  font-weight: 800;
  letter-spacing: .025em;
  backdrop-filter: blur(12px);
}

.chapter-hero-label {
  margin: 0 0 26px;
}

.chapter-hero-copy h1 {
  max-width: 900px;
  margin: 0;
  font-size: clamp(23px, 3.2vw, 45px);
  font-weight: 800;
  line-height: 1.06;
  letter-spacing: -.05em;
  text-wrap: pretty;
  text-shadow: 0 16px 48px rgba(0, 0, 0, .38);
}

.chapter-hero-description {
  max-width: 680px;
  margin: 24px 0 0;
  color: rgba(240, 242, 236, .78);
  font-size: 18px;
  line-height: 1.8;
  text-wrap: pretty;
}

.chapter-background + .chapter-content {
  padding-top: 0;
}

@media (max-width: 720px) {
  .chapter-hero-copy {
    bottom: 54px;
    width: calc(100% - 36px);
  }

  .chapter-hero-label,
  .collection--video .collection-title h3,
  .section-light .collection--video .collection-title h3 {
    min-height: 42px;
    padding: 0 14px;
    font-size: 14px;
  }

  .chapter-hero-label {
    margin-bottom: 20px;
  }

  .chapter-hero-copy h1 {
    font-size: clamp(20px, 5.78vw, 30px);
  }

  .chapter-hero-description {
    margin-top: 18px;
    font-size: 15px;
  }
}

/* v3.5 — every complete work group alternates white / black from its heading */
.collection[data-surface] {
  margin-right: calc(var(--page-pad) * -1);
  margin-left: calc(var(--page-pad) * -1);
  padding: clamp(56px, 7vw, 104px) var(--page-pad);
  color: var(--text);
  transition: background-color 420ms var(--ease), color 420ms ease;
}

.collection[data-surface] + .collection[data-surface] {
  margin-top: 0;
}

.collection[data-surface="white"] {
  background: var(--paper);
  color: var(--text-dark);
}

.collection[data-surface="black"] {
  background: #080b09;
}

.collection[data-surface] .collection-stage,
.collection[data-surface] .collection-stage[data-surface="white"],
.collection[data-surface] .collection-stage[data-surface="gray"],
.collection[data-surface] .collection-stage[data-surface="black"],
.collection[data-surface] .media-card,
.collection[data-surface] .media-card[data-surface="white"],
.collection[data-surface] .media-card[data-surface="gray"],
.collection[data-surface] .media-card[data-surface="black"] {
  background: transparent;
  color: inherit;
}

.collection[data-surface] .collection-header {
  border-bottom-color: rgba(240, 242, 236, .2);
}

.collection[data-surface] .collection-title h3 {
  color: var(--gold);
}

.collection[data-surface] .collection-title span,
.collection[data-surface] .media-card-copy span {
  color: rgba(240, 242, 236, .62);
}

.collection--image[data-surface] .rail-controls {
  border-color: rgba(240, 242, 236, .2);
}

.collection--image[data-surface] .rail-button,
.collection--image[data-surface] .rail-current-title {
  color: var(--text);
}

.collection--image[data-surface] .rail-button {
  border-color: rgba(240, 242, 236, .26);
}

.collection--image[data-surface] .rail-progress {
  color: var(--gold);
}

.collection[data-surface="white"] .collection-header,
.collection[data-surface="white"] .rail-controls {
  border-color: var(--line-dark);
}

.collection[data-surface="white"] .collection-title span,
.collection[data-surface="white"] .media-card-copy span,
.collection[data-surface="white"] .rail-hint {
  color: var(--muted-dark);
}

.collection[data-surface="white"] .rail-button,
.collection[data-surface="white"] .rail-current-title,
.collection[data-surface="white"] .media-card-copy strong {
  color: var(--text-dark);
}

.collection[data-surface="white"] .rail-button {
  border-color: rgba(15, 18, 16, .24);
}

.collection[data-surface="white"] .rail-button:hover:not(:disabled) {
  border-color: var(--gold);
  background: var(--gold);
  color: var(--ink);
}

.collection[data-surface="white"] .rail-progress-track {
  background: rgba(15, 18, 16, .16);
}

/* Remove the blank end-cap so the last work group meets the gold contact area. */
.chapter-page main > .portfolio-section,
.course-library--images {
  padding-bottom: 0;
}

/* v3.6 — surface-aware gold labels and more legible rail status */
.collection[data-surface="white"] .collection-title h3,
.section-light .collection[data-surface="white"] .collection-title h3 {
  border-color: rgba(203, 164, 95, .7);
  background: transparent;
  color: var(--gold);
  backdrop-filter: none;
}

.collection[data-surface="black"] .collection-title h3,
.section-light .collection[data-surface="black"] .collection-title h3 {
  border-color: rgba(203, 164, 95, .5);
  background: rgba(8, 11, 9, .68);
}

.rail-current-title {
  font-size: clamp(18px, 1.45vw, 23px);
  font-weight: 800;
}

.rail-progress {
  min-width: 72px;
  font-size: clamp(15px, 1.1vw, 18px);
}

.rail-hint {
  font-size: clamp(13px, .95vw, 16px);
  line-height: 1.5;
}

.chapter-directory .section-index,
.chapter-directory.section-light .section-index {
  min-height: 46px;
  padding: 0 18px;
  border: 1px solid rgba(203, 164, 95, .72);
  background: transparent;
  color: #84611f !important;
}

@media (max-width: 720px) {
  .collection[data-surface] {
    padding-top: 48px;
    padding-bottom: 48px;
  }

  .rail-current-title {
    font-size: 15px;
  }

  .rail-progress {
    min-width: 54px;
    font-size: 13px;
  }

  .chapter-directory .section-index,
  .chapter-directory.section-light .section-index {
    min-height: 42px;
    padding-inline: 14px;
    font-size: 14px;
  }
}

/* v3.7 — personal/project hero video plus a black tail equal to 1/5 video height */
body[data-page="personal"] .chapter-background,
body[data-page="projects"] .chapter-background {
  height: max(912px, 112.8svh);
  min-height: 0;
  background: #050705;
}

body[data-page="personal"] .chapter-background .ambient-video,
body[data-page="projects"] .chapter-background .ambient-video,
body[data-page="personal"] .chapter-background .cinematic-overlay,
body[data-page="projects"] .chapter-background .cinematic-overlay {
  inset: 0 0 auto;
  height: 83.333333%;
}

body[data-page="personal"] .chapter-background .chapter-hero-copy,
body[data-page="projects"] .chapter-background .chapter-hero-copy {
  bottom: calc(16.666667% + clamp(70px, 10vh, 124px));
}

@media (max-width: 720px) {
  body[data-page="personal"] .chapter-background,
  body[data-page="projects"] .chapter-background {
    height: 984px;
    min-height: 984px;
  }

  body[data-page="personal"] .chapter-background .chapter-hero-copy,
  body[data-page="projects"] .chapter-background .chapter-hero-copy {
    bottom: calc(16.666667% + 54px);
  }

  .collection-title {
    max-width: 100%;
    flex-wrap: wrap;
  }

  .collection-title h3,
  .collection--video .collection-title h3,
  .section-light .collection--video .collection-title h3 {
    width: fit-content;
    max-width: 100%;
    height: auto;
    padding-block: 10px;
    line-height: 1.35;
    white-space: normal;
    text-wrap: pretty;
  }
}

/* v3.8 — homepage-scale chapter heroes, soft side masks, uncropped project previews */
body[data-page="personal"] .chapter-background,
body[data-page="projects"] .chapter-background {
  height: max(864px, 120svh);
  min-height: 0;
}

body[data-page="course"] .course-hero {
  height: max(720px, 100svh);
  min-height: 0;
}

.hero-video,
body[data-page="personal"] .chapter-background .ambient-video,
body[data-page="projects"] .chapter-background .ambient-video,
body[data-page="course"] .course-hero .ambient-video {
  -webkit-mask-image: none;
  mask-image: none;
}

body[data-page="projects"] .collection--video .media-card-visual {
  max-height: none;
  aspect-ratio: 15 / 8;
  background: #050705;
}

body[data-page="projects"] .collection--video .media-card-visual > img,
body[data-page="projects"] .collection--video .media-card-visual > video {
  object-fit: contain;
}

/* v3.9 — blended hero edges and circular side navigation */
.hero-overlay {
  background:
    linear-gradient(90deg, rgba(8, 11, 9, .84) 0%, rgba(8, 11, 9, .28) 56%, rgba(8, 11, 9, .36) 100%),
    linear-gradient(0deg, rgba(8, 11, 9, .66), transparent 48%);
}

.chapter-background .cinematic-overlay {
  background:
    linear-gradient(90deg, rgba(8, 11, 9, .68), transparent 70%),
    linear-gradient(0deg, rgba(8, 11, 9, .68), transparent 52%);
}

.course-hero .course-overlay {
  background:
    linear-gradient(90deg, rgba(8, 11, 9, .88) 0%, rgba(8, 11, 9, .28) 62%, rgba(8, 11, 9, .52) 100%),
    linear-gradient(0deg, rgba(8, 11, 9, .7), transparent 50%);
}

/* v4.0 — foreground edge masks aligned to the rendered video picture */
.hero-overlay,
.chapter-background .cinematic-overlay,
.course-hero .course-overlay {
  --video-content-left: 0px;
  --video-content-right: 0px;
  --video-edge-fade: 3.5vw;
  --video-edge-overlap: 4px;
  pointer-events: none;
}

.hero-overlay::before,
.hero-overlay::after,
.chapter-background .cinematic-overlay::before,
.chapter-background .cinematic-overlay::after,
.course-hero .course-overlay::before,
.course-hero .course-overlay::after {
  content: "";
  position: absolute;
  z-index: 1;
  top: 0;
  bottom: 0;
  width: var(--video-edge-fade);
  background-color: #050705;
  pointer-events: none;
}

.hero-overlay::before,
.chapter-background .cinematic-overlay::before,
.course-hero .course-overlay::before {
  left: var(--video-content-left);
  -webkit-mask-image: linear-gradient(90deg,
    #050705 0%,
    rgba(5, 7, 5, .531) 25%,
    rgba(5, 7, 5, .218) 50%,
    rgba(5, 7, 5, .047) 75%,
    transparent 100%);
  mask-image: linear-gradient(90deg,
    #000 0%,
    rgba(0, 0, 0, .531) 25%,
    rgba(0, 0, 0, .218) 50%,
    rgba(0, 0, 0, .047) 75%,
    transparent 100%);
}

.hero-overlay::after,
.chapter-background .cinematic-overlay::after,
.course-hero .course-overlay::after {
  right: calc(var(--video-content-right) - var(--video-edge-overlap));
  width: calc(var(--video-edge-fade) + var(--video-edge-overlap));
  -webkit-mask-image: linear-gradient(270deg,
    #000 0%,
    rgba(0, 0, 0, .531) 25%,
    rgba(0, 0, 0, .218) 50%,
    rgba(0, 0, 0, .047) 75%,
    transparent 100%);
  mask-image: linear-gradient(270deg,
    #000 0%,
    rgba(0, 0, 0, .531) 25%,
    rgba(0, 0, 0, .218) 50%,
    rgba(0, 0, 0, .047) 75%,
    transparent 100%);
}

/* Personal hero uses a wider smoothstep fade to eliminate the visible video seam. */
body[data-page="personal"] .chapter-background .cinematic-overlay::before {
  -webkit-mask-image: linear-gradient(90deg,
    #000 0%,
    rgba(0, 0, 0, .97) 12%,
    rgba(0, 0, 0, .84) 30%,
    rgba(0, 0, 0, .58) 52%,
    rgba(0, 0, 0, .3) 72%,
    rgba(0, 0, 0, .11) 88%,
    rgba(0, 0, 0, .025) 96%,
    transparent 100%);
  mask-image: linear-gradient(90deg,
    #000 0%,
    rgba(0, 0, 0, .97) 12%,
    rgba(0, 0, 0, .84) 30%,
    rgba(0, 0, 0, .58) 52%,
    rgba(0, 0, 0, .3) 72%,
    rgba(0, 0, 0, .11) 88%,
    rgba(0, 0, 0, .025) 96%,
    transparent 100%);
}

body[data-page="personal"] .chapter-background .cinematic-overlay::after {
  -webkit-mask-image: linear-gradient(270deg,
    #000 0%,
    rgba(0, 0, 0, .97) 12%,
    rgba(0, 0, 0, .84) 30%,
    rgba(0, 0, 0, .58) 52%,
    rgba(0, 0, 0, .3) 72%,
    rgba(0, 0, 0, .11) 88%,
    rgba(0, 0, 0, .025) 96%,
    transparent 100%);
  mask-image: linear-gradient(270deg,
    #000 0%,
    rgba(0, 0, 0, .97) 12%,
    rgba(0, 0, 0, .84) 30%,
    rgba(0, 0, 0, .58) 52%,
    rgba(0, 0, 0, .3) 72%,
    rgba(0, 0, 0, .11) 88%,
    rgba(0, 0, 0, .025) 96%,
    transparent 100%);
}

/* Final page-specific title sizing prevents chapter/course cascade regressions. */
body[data-page="projects"] #projects-title,
body[data-page="course"] #course-title {
  font-size: clamp(23px, 3.2vw, 45px);
}

@media (max-width: 720px) {
  body[data-page="projects"] #projects-title,
  body[data-page="course"] #course-title {
    font-size: clamp(20px, 5.78vw, 30px);
  }
}

.collection-stage {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  grid-template-rows: auto auto;
}

.collection-stage > .rail-controls {
  grid-column: 1;
  grid-row: 1;
  display: flex;
  justify-content: center;
}

.collection-stage > .rail-controls .rail-status {
  width: min(420px, 100%);
}

.collection-stage > .rail-controls[hidden] {
  display: none;
}

.collection-stage > .media-rail,
.collection-stage > .rail-side-navigation {
  grid-column: 1;
  grid-row: 2;
}

.rail-side-navigation {
  z-index: 5;
  min-width: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: clamp(56px, 5vw, 76px);
  margin-inline: clamp(8px, 1.6vw, 26px);
  pointer-events: none;
}

.rail-side-navigation[hidden] {
  display: none;
}

.collection-stage .rail-side-navigation .rail-button {
  width: clamp(52px, 4.4vw, 66px);
  min-width: clamp(52px, 4.4vw, 66px);
  height: clamp(52px, 4.4vw, 66px);
  padding: 0;
  border: 1px solid rgba(255, 255, 255, .86);
  border-radius: 50%;
  background: rgba(5, 7, 5, .58);
  color: #fff;
  box-shadow: 0 12px 34px rgba(0, 0, 0, .28);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  pointer-events: auto;
  transition: color 180ms ease, background 180ms ease, border-color 180ms ease, opacity 180ms ease, transform 180ms var(--ease);
}

.collection-stage .rail-side-navigation .rail-button:hover:not(:disabled),
.collection[data-surface="white"] .collection-stage .rail-side-navigation .rail-button:hover:not(:disabled) {
  border-color: var(--gold);
  background: var(--gold);
  color: var(--ink);
  transform: scale(1.06);
}

.collection-stage .rail-side-navigation .rail-button:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 4px;
}

.rail-side-navigation .rail-arrow-glyph {
  color: currentColor;
  font-size: clamp(24px, 2vw, 31px);
  font-weight: 400;
  line-height: 1;
}

@media (max-width: 720px) {
  .rail-side-navigation {
    padding-top: 58px;
    margin-inline: 6px;
  }

  .collection-stage .rail-side-navigation .rail-button {
    width: 48px;
    min-width: 48px;
    height: 48px;
  }
}

/* v4.3 — preserve the full frame for every non-hero video and poster */
.collection--video .media-card-visual {
  aspect-ratio: 15 / 8;
  background: transparent;
}

.featured-card-visual {
  aspect-ratio: 16 / 9;
  background: transparent;
}

.collection--video .media-card-visual > img,
.collection--video .media-card-visual > video,
.featured-card-visual > img,
.featured-card-visual > video {
  object-fit: contain;
}

.collection--video .media-preview,
.featured-card-visual .media-preview {
  background: transparent;
}

/* v4.4 — unified non-hero media scale and duration-only card heading */
.collection--video .media-card-visual,
.featured-card-visual {
  max-height: min(96svh, 1080px);
}

.collection--video .media-card-copy {
  justify-content: flex-end;
}

.collection--video .media-card-copy strong {
  display: none;
}

@media (max-width: 720px) {
  .collection--video .media-card-visual,
  .featured-card-visual {
    max-height: none;
  }

  .collection--video .media-card-visual {
    aspect-ratio: 15 / 8;
  }

  .featured-card-visual {
    aspect-ratio: 16 / 9;
  }
}

/* v4.5 — project previews use the same frame as Personal / Night Forest 01 */
body[data-page="projects"] .collection--video .media-rail {
  grid-auto-columns: 100%;
}

body[data-page="projects"] .collection--video .media-card,
body[data-page="projects"] .collection--video .media-card-visual {
  width: 100%;
  min-width: 0;
}

body[data-page="projects"] .collection--video .media-card-visual {
  aspect-ratio: 15 / 8;
  max-height: min(96svh, 1080px);
  background: transparent;
}

body[data-page="projects"] .collection--video .media-card-visual > img,
body[data-page="projects"] .collection--video .media-card-visual > video {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

@media (max-width: 720px) {
  body[data-page="projects"] .collection--video .media-card-visual {
    max-height: none;
  }
}
/* v4.9 — surface-aware navigation with a visual marker */
.page-group-nav {
  position: fixed;
  z-index: 84;
  top: 50%;
  right: clamp(8px, 1.25vw, 24px);
  left: auto;
  width: min(200px, 19vw);
  max-height: calc(100vh - 176px);
  padding: 8px 22px 8px 10px;
  border: 0;
  background: transparent;
  box-shadow: none;
  transform: translateY(-50%);
  transition: opacity .22s ease, transform .3s var(--ease);
}

.page-group-nav::before {
  content: "";
  position: absolute;
  top: 4px;
  bottom: 4px;
  right: 5px;
  left: auto;
  width: 1px;
  background: linear-gradient(to bottom, transparent, var(--gold) 12%, var(--gold) 88%, transparent);
}

.page-group-nav::after {
  content: "";
  position: absolute;
  top: 0;
  right: 1px;
  left: auto;
  width: 9px;
  height: 9px;
  border: 1px solid var(--gold);
  background: transparent;
  transform: rotate(45deg);
}

.page-group-nav-title {
  margin: 0 0 18px;
  color: rgba(240, 242, 236, .4);
  font-size: 12px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: .2em;
  text-align: right;
  opacity: 1;
}

.page-group-nav-list {
  display: grid;
  gap: 5px;
}

.page-group-nav button {
  position: relative;
  min-height: 30px;
  margin-block: 0;
  padding: 4px 0;
  border: 0;
  background: transparent;
  color: rgba(240, 242, 236, .72);
  font: inherit;
  font-size: 14px;
  font-weight: 750;
  line-height: 1.25;
  letter-spacing: .025em;
  text-align: right;
  text-wrap: pretty;
  cursor: pointer;
  transform-origin: right center;
  transition: color .18s ease, font-size .18s ease, margin .18s ease, transform .18s ease;
}

.page-group-nav-title[data-tone="light"] {
  color: rgba(8, 11, 9, .4);
}

.page-group-nav button[data-tone="light"] {
  color: rgba(8, 11, 9, .72);
}

.page-group-nav-title[data-tone="dark"] {
  color: rgba(240, 242, 236, .4);
}

.page-group-nav button[data-tone="dark"] {
  color: rgba(240, 242, 236, .72);
}

.page-group-nav button::before {
  content: none;
}

.page-group-nav button[aria-current="location"] {
  margin-block: 8px;
  font-size: 22px;
  transform: translateX(-2px);
}

.page-group-nav button:hover {
  color: var(--gold);
  margin-block: 8px;
  font-size: 22px;
  transform: translateX(-2px);
}

.page-group-nav button:focus-visible {
  outline: 0;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
}

body.viewer-open .page-group-nav {
  opacity: 0;
  pointer-events: none;
}

@media (max-width: 900px) {
  .page-group-nav {
    right: 5px;
    left: auto;
    width: 148px;
    max-height: 64vh;
    padding: 8px 18px 8px 6px;
    overflow-y: auto;
    background: transparent;
  }

  .page-group-nav-title {
    margin-bottom: 14px;
    font-size: 10px;
  }

  .page-group-nav button {
    min-height: 27px;
    padding-left: 0;
    font-size: 12px;
  }

  .page-group-nav button:hover {
    margin-block: 5px;
    font-size: 18px;
  }

  .page-group-nav button[aria-current="location"] {
    margin-block: 5px;
    font-size: 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-group-nav,
  .page-group-nav button {
    transition: none;
  }
}

/* V01 background music library and persistent player */
body.music-enabled { padding-bottom: 92px; }
body.music-enabled.music-player-collapsed { padding-bottom: 22px; }

.music-dock {
  --music-dock-offset: 18px;
  --music-drag-y: 0px;
  --music-idle-y: 0px;
  position: fixed;
  z-index: 350;
  right: 18px;
  bottom: 18px;
  left: 18px;
  width: min(940px, calc(100vw - 36px));
  margin-inline: auto;
  color: #f0f2ec;
  font-family: var(--sans);
  opacity: 1;
  transform: translateY(calc(var(--music-drag-y) + var(--music-idle-y)));
  transition: transform .36s var(--ease), opacity .28s ease;
  touch-action: none;
}

.music-dock.is-collapsed { --music-drag-y: calc(100% + var(--music-dock-offset)); }
.music-dock.is-dragging { transition: none; }

body.ui-idle .site-header {
  opacity: 0;
  pointer-events: none;
}

body.ui-idle .chapter-nav {
  transform: translate(-50%, calc(-100% - 24px));
}

body.ui-idle .page-group-nav {
  opacity: 0;
  pointer-events: none;
  transform: translate(36px, -50%);
}

body.ui-idle .music-dock {
  --music-idle-y: calc(100% + 28px);
  opacity: 0;
  pointer-events: none;
}

.music-dock__bar {
  min-height: 66px;
  display: grid;
  grid-template-columns: minmax(210px, 1fr) auto minmax(260px, 1.25fr);
  align-items: center;
  gap: 18px;
  padding: 9px 14px;
  border: 1px solid rgba(203, 164, 95, .82);
  border-radius: 999px;
  background: rgba(232, 233, 226, .12);
  box-shadow: 0 14px 46px rgba(0, 0, 0, .2), inset 0 0 0 1px rgba(255, 255, 255, .08);
  backdrop-filter: blur(24px) saturate(115%);
}

.music-dock__grip {
  position: absolute;
  z-index: 2;
  bottom: calc(100% + 5px);
  left: 50%;
  width: 92px;
  height: 22px;
  display: grid;
  place-items: center;
  padding: 0;
  border: 1px solid rgba(203, 164, 95, .72);
  border-radius: 999px;
  background: rgba(232, 233, 226, .16);
  box-shadow: 0 8px 28px rgba(0, 0, 0, .18);
  backdrop-filter: blur(18px);
  cursor: ns-resize;
  transform: translateX(-50%);
}

.music-dock__grip span {
  width: 54px;
  height: 4px;
  border-radius: 999px;
  background: var(--gold);
  box-shadow: 0 0 12px rgba(203, 164, 95, .32);
  transition: width .18s ease, background .18s ease;
}

.music-dock__grip:hover span,
.music-dock__grip:focus-visible span {
  width: 64px;
  background: #e1c17e;
}

.music-now {
  min-width: 0;
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr) 18px;
  align-items: center;
  gap: 10px;
  padding: 5px 4px;
  border: 0;
  background: transparent;
  text-align: left;
  cursor: pointer;
}

.music-now__pulse {
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 3px;
  border: 1px solid rgba(203, 164, 95, .72);
  border-radius: 50%;
}

.music-now__pulse i {
  width: 2px;
  height: 7px;
  background: var(--gold);
  transform-origin: center;
}

.music-dock.is-playing .music-now__pulse i { animation: music-equalizer .8s ease-in-out infinite alternate; }
.music-dock.is-playing .music-now__pulse i:nth-child(2) { animation-delay: -.32s; }
.music-dock.is-playing .music-now__pulse i:nth-child(3) { animation-delay: -.58s; }

@keyframes music-equalizer {
  from { transform: scaleY(.55); }
  to { transform: scaleY(1.75); }
}

.music-now__copy {
  min-width: 0;
  display: grid;
  gap: 3px;
}

.music-now__copy small {
  color: rgba(240, 242, 236, .52);
  font-size: 9px;
  font-weight: 800;
  letter-spacing: .14em;
}

.music-now__copy strong {
  overflow: hidden;
  color: #f0f2ec;
  font-size: 14px;
  font-weight: 760;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.music-now__chevron {
  color: var(--gold);
  font-size: 16px;
  transition: transform .24s var(--ease);
}

.music-dock[data-open="true"] .music-now__chevron { transform: rotate(180deg); }

.music-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}

.music-icon-button {
  width: 40px;
  height: 40px;
  display: inline-grid;
  place-items: center;
  padding: 0;
  border: 1px solid rgba(240, 242, 236, .3);
  border-radius: 50%;
  background: rgba(240, 242, 236, .04);
  cursor: pointer;
  transition: border-color .18s ease, color .18s ease, background .18s ease, transform .18s ease;
}

.music-icon-button:hover {
  border-color: var(--gold);
  color: var(--gold);
  background: rgba(203, 164, 95, .1);
  transform: translateY(-1px);
}

.music-icon-button svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
}

.music-play {
  border-color: var(--gold);
  color: var(--ink);
  background: var(--gold);
}

.music-play:hover { color: var(--ink); background: #ddbd7b; }
.music-icon-pause, .music-dock.is-playing .music-icon-play { display: none; }
.music-dock.is-playing .music-icon-pause { display: block; }

.music-timeline {
  min-width: 0;
  display: grid;
  gap: 5px;
}

.music-timeline input[type="range"] {
  --music-progress: 0%;
  width: 100%;
  height: 18px;
  margin: 0;
  appearance: none;
  background: transparent;
  cursor: pointer;
}

.music-timeline input[type="range"]::-webkit-slider-runnable-track {
  height: 2px;
  background: linear-gradient(to right, var(--gold) var(--music-progress), rgba(240, 242, 236, .2) var(--music-progress));
}

.music-timeline input[type="range"]::-webkit-slider-thumb {
  width: 11px;
  height: 11px;
  margin-top: -4.5px;
  appearance: none;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 1px var(--gold);
}

.music-timeline input[type="range"]::-moz-range-track { height: 2px; background: rgba(240, 242, 236, .2); }
.music-timeline input[type="range"]::-moz-range-progress { height: 2px; background: var(--gold); }
.music-timeline input[type="range"]::-moz-range-thumb {
  width: 9px;
  height: 9px;
  border: 2px solid var(--ink);
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 1px var(--gold);
}

.music-time {
  display: flex;
  justify-content: space-between;
  color: rgba(240, 242, 236, .5);
  font-size: 9px;
  font-variant-numeric: tabular-nums;
  letter-spacing: .08em;
}

.music-library {
  position: absolute;
  right: 0;
  bottom: calc(100% + 10px);
  left: 0;
  max-height: min(570px, calc(100vh - 116px));
  overflow-y: auto;
  padding: 24px;
  border: 1px solid rgba(203, 164, 95, .58);
  border-radius: 26px;
  background: rgba(8, 11, 9, .97);
  box-shadow: 0 24px 80px rgba(0, 0, 0, .46);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity .22s ease, visibility .22s ease, transform .22s var(--ease);
}

.music-dock[data-open="true"] .music-library {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.music-library__header {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 18px;
  padding-bottom: 16px;
  border-bottom: 1px solid rgba(240, 242, 236, .16);
}

.music-library__header span {
  color: var(--gold);
  font-size: 9px;
  font-weight: 800;
  letter-spacing: .22em;
}

.music-library__header h2 {
  margin: 5px 0 0;
  font-size: clamp(24px, 4vw, 42px);
  line-height: 1;
}

.music-library__close { flex: 0 0 auto; }
.music-library__list { display: grid; }

.music-library__item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  border-bottom: 1px solid rgba(240, 242, 236, .11);
}

.music-library__item > button {
  min-width: 0;
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  padding: 14px 12px 14px 0;
  border: 0;
  background: transparent;
  text-align: left;
  cursor: pointer;
}

.music-library__item > button:hover strong,
.music-library__item > button.is-current strong { color: var(--gold); }

.music-library__item > button.is-current .music-library__number {
  border-color: var(--gold);
  color: var(--gold);
}

.music-library__number {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(240, 242, 236, .22);
  border-radius: 50%;
  color: rgba(240, 242, 236, .52);
  font-size: 9px;
  font-variant-numeric: tabular-nums;
}

.music-library__names {
  min-width: 0;
  display: grid;
  gap: 3px;
}

.music-library__names strong {
  overflow: hidden;
  color: #f0f2ec;
  font-size: 15px;
  text-overflow: ellipsis;
  white-space: nowrap;
  transition: color .18s ease;
}

.music-library__names small,
.music-library__duration {
  color: rgba(240, 242, 236, .48);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: .04em;
}

.music-library__duration { font-variant-numeric: tabular-nums; }
.music-library__source {
  padding: 10px 5px 10px 15px;
  color: rgba(240, 242, 236, .48);
  font-size: 10px;
  text-decoration: none;
}

.music-library__source:hover { color: var(--gold); }
.music-library__credit {
  margin: 18px 0 0;
  color: rgba(240, 242, 236, .45);
  font-size: 10px;
  line-height: 1.6;
}

.music-library__credit a { color: var(--gold); }

@media (max-width: 700px) {
  body.music-enabled { padding-bottom: 110px; }
  body.music-enabled.music-player-collapsed { padding-bottom: 16px; }
  .music-dock { --music-dock-offset: 8px; right: 8px; bottom: 8px; left: 8px; width: calc(100vw - 16px); }
  .music-dock__bar {
    min-height: 88px;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 7px 12px;
    padding: 8px 10px;
    border-radius: 25px;
  }
  .music-now { grid-template-columns: 30px minmax(0, 1fr) 14px; gap: 8px; }
  .music-now__pulse { width: 30px; height: 30px; }
  .music-controls { gap: 5px; }
  .music-icon-button { width: 36px; height: 36px; }
  .music-timeline { grid-column: 1 / -1; }
  .music-library { bottom: calc(100% + 7px); max-height: calc(100vh - 112px); padding: 18px 14px; }
  .music-library__item > button { grid-template-columns: 34px minmax(0, 1fr) auto; gap: 9px; padding-block: 12px; }
  .music-library__number { width: 28px; height: 28px; }
  .music-library__source { padding-left: 8px; }
}

@media (prefers-reduced-motion: reduce) {
  .music-dock *, .music-library { animation: none !important; transition: none !important; }
}

/* Collapsible right chapter navigation */
.page-group-nav .page-group-nav-toggle {
  position: absolute;
  top: -42px;
  right: 0;
  left: auto;
  width: 28px;
  min-height: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  margin: 0;
  padding: 0;
  border: 1px solid currentColor;
  border-radius: 50%;
  background: transparent;
  color: #fff;
  opacity: .76;
  cursor: pointer;
  transform: translateX(35%);
  transition: color .18s ease, border-color .18s ease, opacity .18s ease, transform .26s var(--ease);
}

.page-group-nav .page-group-nav-toggle svg {
  width: 15px;
  height: 15px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: transform .26s var(--ease);
}

.page-group-nav .page-group-nav-toggle:hover {
  margin: 0;
  border-color: var(--gold);
  color: var(--gold);
  font-size: inherit;
  opacity: 1;
  transform: translateX(35%) scale(1.08);
}

.page-group-nav.is-collapsed {
  overflow: visible;
}

.page-group-nav.is-collapsed::before,
.page-group-nav.is-collapsed::after {
  display: none;
}

.page-group-nav.is-collapsed .page-group-nav-title,
.page-group-nav.is-collapsed .page-group-nav-list {
  visibility: hidden;
  opacity: 0;
  pointer-events: none;
}

.page-group-nav.is-collapsed .page-group-nav-toggle svg { transform: rotate(180deg); }
.page-group-nav.is-collapsed .page-group-nav-toggle:hover { transform: translateX(35%) scale(1.08); }

.page-group-nav .page-group-nav-toggle[data-tone="light"] { color: #080b09; }
.page-group-nav .page-group-nav-toggle[data-tone="dark"] { color: #fff; }

/* Minimal gold music controls */
body.music-enabled { padding-bottom: 68px; }
body.music-enabled.music-player-collapsed { padding-bottom: 18px; }

.music-dock { width: min(620px, calc(100vw - 36px)); }

.music-dock__bar {
  min-height: 50px;
  grid-template-columns: auto minmax(220px, 1fr);
  gap: 16px;
  padding: 4px 0;
  border: 0;
  border-radius: 0;
  background: transparent;
  box-shadow: none;
  backdrop-filter: none;
}

.music-now,
.music-library {
  display: none !important;
}

.music-dock__grip {
  bottom: calc(100% + 1px);
  width: 88px;
  height: 18px;
  border: 0;
  background: transparent;
  box-shadow: none;
  backdrop-filter: none;
}

.music-dock__grip svg {
  width: 18px;
  height: 18px;
  fill: var(--gold);
  stroke: none;
  transition: transform .24s var(--ease), opacity .18s ease;
}

.music-dock__grip:hover svg,
.music-dock__grip:focus-visible svg { opacity: .72; transform: translateY(2px); }

.music-dock.is-collapsed .music-dock__grip svg { transform: rotate(180deg); }
.music-dock.is-collapsed .music-dock__grip:hover svg,
.music-dock.is-collapsed .music-dock__grip:focus-visible svg { transform: rotate(180deg) translateY(2px); }

.music-controls { gap: 7px; }

.music-icon-button,
.music-play {
  width: 42px;
  height: 42px;
  border-color: var(--gold);
  color: var(--gold);
  background: transparent;
  box-shadow: none;
}

.music-icon-button:hover,
.music-play:hover {
  border-color: var(--gold);
  color: var(--gold);
  background: transparent;
  transform: scale(1.06);
}

.music-timeline { gap: 0; }
.music-time { display: none; }

.music-timeline input[type="range"]::-webkit-slider-runnable-track {
  height: 3px;
  background: linear-gradient(to right, var(--gold) var(--music-progress), rgba(203, 164, 95, .28) var(--music-progress));
}

.music-timeline input[type="range"]::-webkit-slider-thumb {
  width: 12px;
  height: 12px;
  margin-top: -4.5px;
  border-color: transparent;
  background: var(--gold);
  box-shadow: 0 0 0 1px var(--gold);
}

.music-timeline input[type="range"]::-moz-range-track { height: 3px; background: rgba(203, 164, 95, .28); }
.music-timeline input[type="range"]::-moz-range-progress { height: 3px; background: var(--gold); }
.music-timeline input[type="range"]::-moz-range-thumb { border-color: transparent; background: var(--gold); box-shadow: 0 0 0 1px var(--gold); }

@media (max-width: 700px) {
  body.music-enabled { padding-bottom: 62px; }
  body.music-enabled.music-player-collapsed { padding-bottom: 14px; }
  .music-dock { width: calc(100vw - 24px); }
  .music-dock__bar {
    min-height: 48px;
    grid-template-columns: auto minmax(0, 1fr);
    gap: 11px;
    padding: 3px 0;
    border-radius: 0;
  }
  .music-timeline { grid-column: auto; }
  .music-icon-button,
  .music-play { width: 38px; height: 38px; }
}

/* v5.1 — course image groups browse one still at a time, matching video rails. */
body[data-page="course"] #course-video-collections .collection--image .media-rail {
  grid-auto-columns: 100%;
  gap: 24px;
}

body[data-page="course"] #course-video-collections .collection--image .media-card,
body[data-page="course"] #course-video-collections .collection--image .media-card-visual {
  width: 100%;
  min-width: 0;
}

body[data-page="course"] #course-video-collections .collection--image .media-card-visual {
  aspect-ratio: 15 / 8;
  max-height: min(96svh, 1080px);
  background: transparent;
}

body[data-page="course"] #course-video-collections .collection--image .media-card-visual > img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

@media (max-width: 720px) {
  body[data-page="course"] #course-video-collections .collection--image .media-card-visual {
    max-height: none;
  }
}

/* v5.2 — remove redundant course framing and keep image labels in rail status only. */
body[data-page="course"] .course-library {
  padding-top: 0;
  padding-bottom: 0;
}

body[data-page="course"] #course-video-collections .collection--image .media-card-copy {
  justify-content: flex-end;
}

body[data-page="course"] #course-video-collections .collection--image .media-card-copy strong {
  display: none;
}

/* v5.3 — Tropical Forest stills use the same full-width stage as video groups. */
body[data-page="personal"] .collection--image[data-collection-label="热带森林"] .media-rail {
  grid-auto-columns: 100%;
  gap: 24px;
}

body[data-page="personal"] .collection--image[data-collection-label="热带森林"] .media-card,
body[data-page="personal"] .collection--image[data-collection-label="热带森林"] .media-card-visual {
  width: 100%;
  min-width: 0;
}

body[data-page="personal"] .collection--image[data-collection-label="热带森林"] .media-card-visual {
  aspect-ratio: 15 / 8;
  max-height: min(96svh, 1080px);
  background: transparent;
}

body[data-page="personal"] .collection--image[data-collection-label="热带森林"] .media-card-visual > img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

@media (max-width: 720px) {
  body[data-page="personal"] .collection--image[data-collection-label="热带森林"] .media-card-visual {
    max-height: none;
  }
}

/* v6 — guestbook extension */
.guestbook-page {
  background: var(--paper);
}

.guestbook-hero {
  position: relative;
  min-height: min(72svh, 760px);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: 22px;
  overflow: hidden;
  padding: calc(var(--header-height) + 88px) var(--page-pad) clamp(72px, 9vw, 126px);
  background:
    linear-gradient(90deg, transparent 0 24%, rgba(203, 164, 95, .12) 24% calc(24% + 1px), transparent calc(24% + 1px)),
    linear-gradient(0deg, rgba(203, 164, 95, .1) 0 1px, transparent 1px 100%),
    var(--ink);
  background-size: auto, 100% 25%, auto;
  color: var(--text);
}

.guestbook-hero::after {
  content: "";
  position: absolute;
  right: var(--page-pad);
  bottom: clamp(72px, 9vw, 126px);
  width: clamp(90px, 13vw, 190px);
  height: 1px;
  background: var(--gold);
  box-shadow: 30px -10px 0 rgba(203, 164, 95, .45);
}

.guestbook-hero > * {
  position: relative;
  z-index: 1;
}

.guestbook-hero > p {
  margin: 0;
  color: var(--gold);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: .18em;
}

.guestbook-hero h1 {
  max-width: 8ch;
  margin: 0;
  font-size: clamp(70px, 11vw, 150px);
  font-weight: 900;
  letter-spacing: -.075em;
  line-height: .88;
}

.guestbook-hero > div {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 34px;
  color: var(--muted);
  font-size: 13px;
}

.guestbook-board {
  min-height: 70svh;
  padding: clamp(72px, 9vw, 130px) var(--page-pad) clamp(110px, 13vw, 190px);
  color: var(--text-dark);
}

.guestbook-tabs {
  display: flex;
  gap: 34px;
  margin-bottom: clamp(54px, 7vw, 100px);
  border-bottom: 1px solid var(--line-dark);
}

.guestbook-tabs button {
  position: relative;
  min-height: 58px;
  padding: 0 2px;
  border: 0;
  background: transparent;
  color: var(--muted-dark);
  cursor: pointer;
  font-size: clamp(18px, 2vw, 28px);
  font-weight: 800;
  transition: color 180ms ease;
}

.guestbook-tabs button::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: -1px;
  left: 0;
  height: 2px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 220ms var(--ease);
}

.guestbook-tabs button:hover,
.guestbook-tabs button[aria-selected="true"] {
  color: var(--text-dark);
}

.guestbook-tabs button[aria-selected="true"]::after {
  transform: scaleX(1);
}

.guestbook-panel-heading {
  display: grid;
  grid-template-columns: minmax(260px, .8fr) minmax(280px, 1.2fr);
  gap: clamp(36px, 8vw, 150px);
  align-items: end;
  margin-bottom: clamp(52px, 7vw, 92px);
}

.guestbook-panel-heading p,
.guestbook-panel-heading h2 {
  margin: 0;
}

.guestbook-panel-heading > div > p {
  margin-bottom: 14px;
  color: #9a7538;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: .18em;
}

.guestbook-panel-heading h2 {
  font-size: clamp(38px, 5.5vw, 78px);
  font-weight: 900;
  letter-spacing: -.055em;
  line-height: .98;
}

.guestbook-panel-heading > p {
  max-width: 54ch;
  color: var(--muted-dark);
  font-size: clamp(14px, 1.25vw, 18px);
  line-height: 1.8;
  text-wrap: pretty;
}

.guestbook-form {
  max-width: 980px;
  display: grid;
  grid-template-columns: minmax(180px, .34fr) minmax(0, 1fr);
  gap: 28px;
  margin-bottom: clamp(82px, 10vw, 150px);
}

.guestbook-form label {
  display: grid;
  align-content: start;
  gap: 12px;
}

.guestbook-form label:nth-of-type(2) {
  grid-row: span 2;
}

.guestbook-form label > span {
  font-size: 13px;
  font-weight: 800;
}

.guestbook-form label small {
  color: var(--muted-dark);
  font-weight: 500;
}

.guestbook-form input,
.guestbook-form textarea {
  width: 100%;
  border: 1px solid var(--line-dark);
  border-radius: 0;
  background: rgba(255, 255, 255, .24);
  color: var(--text-dark);
  font: inherit;
  font-size: 16px;
  line-height: 1.7;
  transition: border-color 180ms ease, background 180ms ease;
}

.guestbook-form input {
  min-height: 54px;
  padding: 0 16px;
}

.guestbook-form textarea {
  min-height: 180px;
  resize: vertical;
  padding: 14px 16px;
}

.guestbook-form input:focus,
.guestbook-form textarea:focus {
  outline: none;
  border-color: var(--gold);
  background: rgba(255, 255, 255, .5);
}

.guestbook-form-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.guestbook-form-footer > span,
.guestbook-form-status {
  color: var(--muted-dark);
  font-size: 12px;
}

.guestbook-form-footer button,
.guestbook-list-heading button {
  min-height: 48px;
  padding: 0 18px;
  border: 1px solid var(--gold);
  background: transparent;
  color: var(--text-dark);
  cursor: pointer;
  font-size: 13px;
  font-weight: 800;
  transition: background 180ms ease, color 180ms ease;
}

.guestbook-form-footer button:hover,
.guestbook-list-heading button:hover {
  background: var(--gold);
}

.guestbook-form-footer button:disabled {
  cursor: wait;
  opacity: .45;
}

.guestbook-form-status {
  min-height: 20px;
  margin: 0;
}

.guestbook-list-heading {
  min-height: 74px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  border-bottom: 1px solid var(--line-dark);
}

.guestbook-list-heading h2 {
  margin: 0;
  font-size: clamp(24px, 3vw, 40px);
}

.guestbook-list-heading button {
  min-height: 40px;
  padding-inline: 14px;
}

.guestbook-message {
  display: grid;
  grid-template-columns: minmax(230px, .42fr) minmax(0, 1fr);
  gap: clamp(28px, 7vw, 130px);
  padding: clamp(30px, 4.4vw, 66px) 0;
  border-bottom: 1px solid var(--line-dark);
}

.guestbook-message header {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 7px 14px;
  align-content: start;
}

.guestbook-message header span {
  color: var(--gold);
  font-size: 11px;
  font-weight: 800;
}

.guestbook-message header strong {
  font-size: 18px;
}

.guestbook-message time {
  grid-column: 2;
  color: var(--muted-dark);
  font-size: 12px;
}

.guestbook-message > p {
  margin: 0;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  font-size: clamp(16px, 1.45vw, 21px);
  line-height: 1.8;
}

.visitor-list article {
  min-height: 76px;
  display: grid;
  grid-template-columns: minmax(170px, 1fr) minmax(130px, .7fr) minmax(130px, .7fr);
  gap: 24px;
  align-items: center;
  border-bottom: 1px solid var(--line-dark);
}

.visitor-list time,
.visitor-list span {
  color: var(--muted-dark);
  font-size: 14px;
}

.visitor-list strong {
  font-size: 15px;
}

.guestbook-empty {
  margin: 0;
  padding: 42px 0;
  border-bottom: 1px solid var(--line-dark);
  color: var(--muted-dark);
}

@media (max-width: 720px) {
  .guestbook-hero {
    min-height: 620px;
    padding-bottom: 70px;
  }

  .guestbook-hero::after {
    right: 18px;
    bottom: 70px;
  }

  .guestbook-hero h1 {
    font-size: clamp(64px, 24vw, 104px);
  }

  .guestbook-panel-heading,
  .guestbook-form,
  .guestbook-message {
    grid-template-columns: 1fr;
  }

  .guestbook-form label:nth-of-type(2) {
    grid-row: auto;
  }

  .guestbook-message {
    gap: 22px;
  }

  .visitor-list article {
    grid-template-columns: 1fr 1fr;
    gap: 8px 18px;
    padding: 20px 0;
  }

  .visitor-list span {
    grid-column: 1 / -1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .guestbook-tabs button::after,
  .guestbook-form input,
  .guestbook-form textarea,
  .guestbook-form-footer button,
  .guestbook-list-heading button {
    transition: none;
  }
}

/* v7 — editorial guestbook */
.guestbook-page .guestbook-intro {
  position: relative;
  min-height: min(58svh, 620px);
  display: grid;
  grid-template-columns: 90px minmax(0, 1fr) minmax(250px, 330px);
  gap: clamp(28px, 5vw, 86px);
  align-items: end;
  padding: calc(var(--header-height) + 84px) var(--page-pad) clamp(64px, 7vw, 104px);
  overflow: hidden;
  background: var(--ink);
  color: var(--text);
}

.guestbook-page .guestbook-intro::before {
  content: "";
  position: absolute;
  top: var(--header-height);
  right: var(--page-pad);
  bottom: 0;
  left: var(--page-pad);
  border-top: 1px solid rgba(240, 242, 236, .12);
  border-bottom: 1px solid rgba(203, 164, 95, .34);
  pointer-events: none;
}

.guestbook-intro__index,
.guestbook-intro__title,
.guestbook-identity {
  position: relative;
  z-index: 1;
}

.guestbook-intro__index {
  min-height: 154px;
  display: grid;
  grid-template-rows: auto 1fr auto;
  justify-items: center;
  gap: 12px;
  color: var(--gold);
  font-size: 10px;
  font-weight: 800;
  letter-spacing: .16em;
}

.guestbook-intro__index i {
  width: 1px;
  height: 100%;
  background: rgba(203, 164, 95, .5);
}

.guestbook-intro__index span:last-child {
  writing-mode: vertical-rl;
}

.guestbook-intro__title > p {
  margin: 0 0 18px;
  color: var(--gold);
  font-size: 10px;
  font-weight: 800;
  letter-spacing: .2em;
}

.guestbook-intro__title h1 {
  max-width: none;
  margin: 0;
  font-size: clamp(54px, 7.2vw, 104px);
  font-weight: 900;
  letter-spacing: -.07em;
  line-height: .92;
}

.guestbook-identity {
  display: grid;
  gap: 10px;
  padding: 22px 0;
  border-top: 1px solid rgba(240, 242, 236, .18);
  border-bottom: 1px solid rgba(240, 242, 236, .18);
}

.guestbook-identity small {
  color: var(--gold);
  font-size: 9px;
  font-weight: 800;
  letter-spacing: .18em;
}

.guestbook-identity strong {
  font-size: clamp(19px, 2vw, 28px);
  letter-spacing: .04em;
}

.guestbook-identity span {
  color: var(--muted);
  font-size: 11px;
}

.guestbook-page .guestbook-board {
  padding-top: 0;
}

.guestbook-board-head {
  min-height: 112px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  border-bottom: 1px solid var(--line-dark);
}

.guestbook-board-head > p {
  margin: 0;
  color: var(--muted-dark);
  font-size: 11px;
  letter-spacing: .08em;
}

.guestbook-page .guestbook-tabs {
  align-self: stretch;
  gap: 36px;
  margin: 0;
  border: 0;
}

.guestbook-page .guestbook-tabs button {
  min-height: 100%;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 2px;
  font-size: 18px;
}

.guestbook-page .guestbook-tabs button span {
  color: #9a7538;
  font-size: 9px;
  letter-spacing: .08em;
}

.guestbook-page .guestbook-tabs button::after {
  height: 3px;
}

.guestbook-page .guestbook-panel {
  padding-top: clamp(76px, 8vw, 118px);
}

.guestbook-page .guestbook-panel-heading {
  grid-template-columns: minmax(260px, .8fr) minmax(300px, 1fr);
  align-items: start;
  margin-bottom: clamp(54px, 7vw, 96px);
}

.guestbook-page .guestbook-panel-heading h2 {
  font-size: clamp(38px, 4.6vw, 66px);
}

.guestbook-page .guestbook-form {
  max-width: none;
  display: grid;
  grid-template-columns: minmax(230px, 300px) minmax(0, 1fr);
  gap: 0;
  margin-bottom: clamp(94px, 11vw, 166px);
  border-top: 1px solid var(--line-dark);
  border-bottom: 1px solid var(--line-dark);
}

.guestbook-form-rail {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 42px;
  padding: 28px 28px 28px 0;
  border-right: 1px solid var(--line-dark);
}

.guestbook-page .guestbook-name-field {
  gap: 14px;
}

.guestbook-page .guestbook-name-field > span,
.guestbook-page .guestbook-message-field > span {
  color: #8e6a31;
  font-size: 10px;
  font-weight: 800;
  letter-spacing: .16em;
}

.guestbook-page .guestbook-name-field input {
  min-height: 54px;
  padding: 0;
  border: 0;
  border-bottom: 1px solid var(--line-dark);
  background: transparent;
  font-size: 18px;
  font-weight: 750;
}

.guestbook-name-field > small {
  color: var(--muted-dark);
  font-size: 11px;
  line-height: 1.6;
}

.guestbook-name-field > small b {
  color: var(--text-dark);
  font-weight: 750;
}

.guestbook-page .guestbook-submit {
  width: 100%;
  min-height: 94px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 22px;
  border: 1px solid var(--gold);
  background: transparent;
  color: var(--text-dark);
  cursor: pointer;
  font-size: 15px;
  font-weight: 850;
  transition: background 220ms ease, color 220ms ease;
}

.guestbook-page .guestbook-submit b {
  font-size: 24px;
  font-weight: 400;
  transition: transform 220ms var(--ease);
}

.guestbook-page .guestbook-submit:hover {
  background: var(--gold);
}

.guestbook-page .guestbook-submit:hover b {
  transform: translate(4px, -4px);
}

.guestbook-page .guestbook-submit:disabled {
  cursor: wait;
  opacity: .45;
}

.guestbook-page .guestbook-message-field {
  position: relative;
  min-height: 330px;
  display: grid;
  grid-template-rows: auto 1fr auto;
  gap: 20px;
  padding: 30px 0 24px 42px;
}

.guestbook-page .guestbook-message-field textarea {
  min-height: 230px;
  padding: 0;
  border: 0;
  background: transparent;
  font-size: clamp(18px, 1.65vw, 24px);
  line-height: 1.75;
}

.guestbook-page .guestbook-message-field textarea:focus,
.guestbook-page .guestbook-name-field input:focus {
  background: transparent;
  box-shadow: none;
}

.guestbook-message-field > small {
  justify-self: end;
  color: var(--muted-dark);
  font-size: 11px;
  letter-spacing: .08em;
}

.guestbook-page .guestbook-form-status {
  grid-column: 2;
  min-height: 24px;
  margin: 0;
  padding: 14px 0 0 42px;
}

.guestbook-form-status[data-state="success"] {
  color: #6c7735;
}

.guestbook-form-status[data-state="error"] {
  color: #9c463b;
}

.guestbook-page .guestbook-list-heading {
  min-height: 104px;
}

.guestbook-list-heading > div {
  display: grid;
  gap: 8px;
}

.guestbook-list-heading small {
  color: #9a7538;
  font-size: 9px;
  font-weight: 800;
  letter-spacing: .16em;
}

.guestbook-page .guestbook-list-heading h2 {
  font-size: clamp(26px, 3vw, 42px);
}

.guestbook-page .guestbook-list-heading button {
  min-height: 42px;
  border-color: var(--line-dark);
  font-size: 11px;
}

.guestbook-page .guestbook-list-heading button:hover {
  border-color: var(--gold);
}

.guestbook-page .guestbook-message {
  grid-template-columns: 46px minmax(130px, .55fr) minmax(260px, 1.5fr) minmax(145px, .55fr);
  gap: clamp(20px, 3vw, 52px);
  align-items: baseline;
  padding: clamp(34px, 4.4vw, 62px) 0;
}

.guestbook-page .guestbook-message > span {
  color: var(--gold);
  font-size: 10px;
  font-weight: 800;
}

.guestbook-page .guestbook-message > strong {
  font-size: 16px;
  overflow-wrap: anywhere;
}

.guestbook-page .guestbook-message > p {
  font-size: clamp(16px, 1.3vw, 19px);
}

.guestbook-page .guestbook-message > time {
  justify-self: end;
  color: var(--muted-dark);
  font-size: 11px;
}

.visitor-day {
  border-bottom: 1px solid var(--line-dark);
}

.visitor-day > header {
  min-height: 78px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  border-bottom: 1px solid var(--line-dark);
}

.visitor-day > header h3 {
  margin: 0;
  font-size: clamp(20px, 2vw, 28px);
}

.visitor-day > header span {
  color: #9a7538;
  font-size: 11px;
  font-weight: 750;
}

.guestbook-page .visitor-day article {
  min-height: 68px;
  display: grid;
  grid-template-columns: minmax(110px, .5fr) minmax(160px, 1fr) minmax(160px, 1fr);
  gap: 24px;
  align-items: center;
  border-bottom: 1px solid rgba(17, 20, 16, .1);
}

.guestbook-page .visitor-day article:last-child {
  border-bottom: 0;
}

@media (max-width: 900px) {
  .guestbook-page .guestbook-intro {
    grid-template-columns: 62px minmax(0, 1fr);
  }

  .guestbook-identity {
    grid-column: 2;
    width: min(100%, 420px);
  }

  .guestbook-page .guestbook-panel-heading {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .guestbook-page .guestbook-message {
    grid-template-columns: 34px minmax(120px, .5fr) minmax(0, 1fr);
  }

  .guestbook-page .guestbook-message > time {
    grid-column: 2;
    justify-self: start;
  }
}

@media (max-width: 720px) {
  .guestbook-page .guestbook-intro {
    min-height: 590px;
    grid-template-columns: 34px minmax(0, 1fr);
    gap: 20px;
    padding-right: 20px;
    padding-left: 20px;
  }

  .guestbook-intro__title h1 {
    font-size: clamp(48px, 16vw, 72px);
  }

  .guestbook-board-head {
    min-height: 96px;
  }

  .guestbook-board-head > p {
    display: none;
  }

  .guestbook-page .guestbook-tabs {
    width: 100%;
  }

  .guestbook-page .guestbook-tabs button {
    flex: 1;
    justify-content: center;
  }

  .guestbook-page .guestbook-form {
    grid-template-columns: 1fr;
  }

  .guestbook-form-rail {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 128px;
    gap: 22px;
    padding: 24px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line-dark);
  }

  .guestbook-page .guestbook-submit {
    min-height: 100%;
  }

  .guestbook-page .guestbook-message-field {
    min-height: 300px;
    padding: 26px 0;
  }

  .guestbook-page .guestbook-form-status {
    grid-column: 1;
    padding-left: 0;
  }

  .guestbook-page .guestbook-message {
    grid-template-columns: 34px minmax(0, 1fr);
    gap: 10px 18px;
  }

  .guestbook-page .guestbook-message > p {
    grid-column: 1 / -1;
    padding-top: 14px;
  }

  .guestbook-page .guestbook-message > time {
    grid-column: 2;
  }

  .guestbook-page .visitor-day article {
    grid-template-columns: 90px minmax(0, 1fr);
    gap: 8px 16px;
    padding: 16px 0;
  }

  .guestbook-page .visitor-day article span {
    grid-column: 2;
  }
}