:root {
  --primary-red: #9f1c22;
  --primary-red-deep: #6d0f15;
  --primary-red-bright: #c7302c;
  --accent-gold: #d6a34a;
  --accent-gold-soft: #f2deb1;
  --paper-bg: #f8f0e1;
  --paper-strong: #fffaf2;
  --ink: #201718;
  --ink-soft: #5f4b4c;
  --line: rgba(118, 31, 31, 0.16);
  --panel-shadow: 0 24px 40px rgba(75, 17, 17, 0.12);
  --radius-xl: 30px;
  --radius-lg: 24px;
  --radius-md: 18px;
  --radius-sm: 14px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(214, 163, 74, 0.2), transparent 20%),
    radial-gradient(circle at top right, rgba(199, 48, 44, 0.2), transparent 28%),
    linear-gradient(180deg, #f4e7d3 0%, #f6eee1 38%, #efe2cf 100%);
  min-height: 100vh;
}

body::before,
body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}

body::before {
  background-image:
    linear-gradient(rgba(159, 28, 34, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(159, 28, 34, 0.05) 1px, transparent 1px);
  background-size: 36px 36px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.55), transparent 70%);
}

body::after {
  background:
    radial-gradient(circle at 10% 18%, rgba(159, 28, 34, 0.08), transparent 16%),
    radial-gradient(circle at 90% 8%, rgba(214, 163, 74, 0.1), transparent 18%);
}

.page-shell {
  position: relative;
  z-index: 1;
  width: min(1220px, calc(100vw - 30px));
  margin: 0 auto;
  padding: 24px 0 60px;
}

.eyebrow,
.section-heading__eyebrow,
.modal__eyebrow {
  margin: 0 0 12px;
  color: var(--primary-red);
  font-size: 0.82rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.hero-poster h1,
.section-heading h2,
.panel h3,
.panel h4,
.timeline-period h3,
.resource-card h3,
.reflection-card h3,
.modal__header h3,
.service-card h2 {
  font-family: "STZhongsong", "Noto Serif SC", "Songti SC", serif;
}

.hero-poster {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.46fr) minmax(320px, 0.74fr);
  gap: 22px;
  padding: 34px;
  border-radius: var(--radius-xl);
  overflow: hidden;
  background:
    linear-gradient(150deg, rgba(105, 13, 19, 0.98), rgba(159, 28, 34, 0.95) 46%, rgba(198, 53, 47, 0.92)),
    linear-gradient(180deg, rgba(255, 255, 255, 0.06), rgba(255, 255, 255, 0));
  box-shadow: 0 28px 54px rgba(63, 7, 11, 0.28);
  color: #fff7eb;
}

.hero-poster__texture {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 18% 18%, rgba(255, 255, 255, 0.14), transparent 18%),
    linear-gradient(130deg, rgba(255, 255, 255, 0.07), transparent 55%),
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='280' height='280' viewBox='0 0 280 280'%3E%3Cg fill='none' stroke='%23f6d698' stroke-opacity='.12'%3E%3Cpath d='M6 158c24-26 50-39 78-39 42 0 72 19 116 70'/%3E%3Cpath d='M28 212c18-17 32-25 44-25 22 0 39 8 75 43'/%3E%3Cpath d='M180 28c18 18 31 40 40 64'/%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.9;
}

.hero-poster__main,
.hero-poster__side {
  position: relative;
  z-index: 1;
}

.hero-poster .eyebrow {
  display: inline-flex;
  align-items: center;
  padding: 8px 14px;
  border-radius: 999px;
  background: rgba(255, 245, 223, 0.96);
  color: var(--primary-red-deep);
  box-shadow: 0 10px 18px rgba(52, 8, 10, 0.12);
}

.hero-ribbon {
  display: inline-flex;
  align-items: center;
  margin-bottom: 16px;
  padding: 10px 18px;
  border-radius: 999px;
  background: linear-gradient(135deg, rgba(255, 246, 220, 0.95), rgba(241, 214, 155, 0.92));
  color: var(--primary-red-deep);
  font-weight: 700;
  letter-spacing: 0.06em;
  box-shadow: 0 14px 26px rgba(52, 8, 10, 0.18);
}

.hero-poster h1 {
  margin: 0;
  font-size: clamp(2.5rem, 4.4vw, 4rem);
  line-height: 1.08;
  white-space: nowrap;
  letter-spacing: 0.01em;
}

.hero-lead {
  max-width: 54ch;
  margin: 18px 0 0;
  color: rgba(255, 247, 235, 0.9);
  font-size: 1.05rem;
  line-height: 1.85;
}

.hero-quote {
  position: relative;
  margin-top: 24px;
  max-width: 620px;
  padding: 18px 20px 18px 22px;
  border-radius: var(--radius-md);
  background: rgba(255, 246, 230, 0.12);
  border: 1px solid rgba(255, 229, 182, 0.24);
  backdrop-filter: blur(8px);
}

.hero-quote::after {
  content: "★";
  position: absolute;
  right: 18px;
  top: 18px;
  color: rgba(255, 232, 186, 0.45);
  font-size: 1.5rem;
}

.hero-quote__label {
  display: inline-block;
  margin-bottom: 8px;
  color: rgba(255, 237, 193, 0.88);
  font-size: 0.86rem;
}

.hero-quote p {
  margin: 0;
  font-size: 1.08rem;
  line-height: 1.85;
}

.hero__meta,
.source-tags,
.resource-tags,
.timeline-badges,
.period-card__tags,
.hero-points {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.hero__meta {
  margin-top: 24px;
}

.meta-chip,
.tag,
.badge,
.theme-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border-radius: 999px;
  font-size: 0.9rem;
}

.meta-chip {
  background: rgba(255, 248, 233, 0.94);
  color: var(--primary-red-deep);
  border: 1px solid rgba(214, 163, 74, 0.28);
}

.meta-chip strong {
  color: var(--primary-red);
}

.hero-points {
  margin-top: 18px;
}

.theme-chip {
  background: rgba(255, 245, 217, 0.16);
  color: #fff2cf;
  border: 1px solid rgba(255, 223, 158, 0.22);
}

.hero__actions,
.modal__actions,
.resource-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.hero__actions {
  margin-top: 24px;
}

.action-pill,
.ghost-button,
.ai-action button,
.resource-actions button,
.resource-actions a,
.slide-nav button,
.slide-thumb {
  appearance: none;
  border: 1px solid rgba(159, 28, 34, 0.16);
  border-radius: 999px;
  background: rgba(255, 251, 245, 0.95);
  color: var(--ink);
  cursor: pointer;
  font: inherit;
  text-decoration: none;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.action-pill,
.ghost-button,
.resource-actions button,
.resource-actions a,
.slide-nav button {
  padding: 12px 18px;
}

.action-pill:hover,
.ghost-button:hover,
.ai-action button:hover,
.resource-actions button:hover,
.resource-actions a:hover,
.slide-nav button:hover,
.slide-thumb:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 24px rgba(98, 18, 18, 0.14);
  border-color: rgba(159, 28, 34, 0.34);
}

.action-pill--solid,
.resource-actions a.resource-actions__download,
.ai-action.is-active button,
.slide-nav button {
  border-color: transparent;
  background: linear-gradient(135deg, var(--primary-red), var(--primary-red-bright));
  color: #fff8ef;
}

.hero-poster__side {
  display: grid;
  gap: 16px;
}

.poster-stamp,
.route-card,
.service-card,
.panel,
.resource-card,
.reflection-card,
.timeline-period,
.ai-action,
.modal__dialog,
.section-nav,
.period-card,
.extension-item {
  background: rgba(255, 250, 242, 0.98);
  border: 1px solid var(--line);
  box-shadow: var(--panel-shadow);
}

.poster-stamp,
.route-card,
.service-card {
  padding: 22px;
  border-radius: var(--radius-lg);
}

.poster-stamp {
  position: relative;
  overflow: hidden;
}

.poster-stamp::before {
  content: "★";
  position: absolute;
  right: 18px;
  top: 10px;
  font-size: 3.2rem;
  color: rgba(159, 28, 34, 0.12);
}

.poster-stamp__title,
.route-card__label {
  display: block;
  margin-bottom: 10px;
  color: var(--primary-red);
  font-size: 0.82rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.poster-stamp strong {
  display: block;
  color: var(--primary-red-deep);
  font-family: "STZhongsong", "Noto Serif SC", "Songti SC", serif;
  font-size: 1.24rem;
  line-height: 1.6;
}

.poster-stamp p,
.service-card li,
.route-step p,
.route-step small,
.section-heading p,
.panel__subhead,
.page-footer p,
.resource-card p,
.timeline-activity__aside p,
.preview-section p,
.preview-callout p,
.preview-links p,
.reflection-card p,
.extension-item p {
  color: var(--ink-soft);
  line-height: 1.78;
}

.poster-stamp p {
  margin: 12px 0 0;
}

.route-card__head {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.route-card__head strong {
  color: var(--primary-red-deep);
  font-family: "STZhongsong", "Noto Serif SC", serif;
}

.hero-route {
  display: grid;
  gap: 14px;
  margin-top: 16px;
}

.route-step {
  position: relative;
  padding: 16px 16px 16px 52px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, rgba(255, 248, 235, 0.98), rgba(247, 236, 217, 0.94));
  border: 1px solid rgba(214, 163, 74, 0.24);
}

.route-step::before {
  content: attr(data-marker);
  position: absolute;
  left: 14px;
  top: 14px;
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  font-size: 0.92rem;
  font-weight: 700;
  color: #fff8ef;
}

.route-step--stream::before {
  background: linear-gradient(135deg, #2d7f98, #3aabc0);
}

.route-step--road::before {
  background: linear-gradient(135deg, var(--primary-red), var(--primary-red-bright));
}

.route-step strong {
  display: block;
  margin-bottom: 6px;
  color: var(--ink);
}

.service-card h2 {
  margin: 0 0 10px;
  font-size: 1.12rem;
  color: var(--primary-red-deep);
}

.service-card ul,
.check-list,
.focus-card ul,
.timeline-details ul,
.preview-list {
  margin: 0;
  padding-left: 20px;
}

.service-card li + li,
.check-list li + li,
.focus-card li + li,
.timeline-details li + li,
.preview-list li + li {
  margin-top: 10px;
}

.section-nav {
  position: sticky;
  top: 12px;
  z-index: 15;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 22px 0 26px;
  padding: 12px;
  border-radius: 999px;
}

.section-nav a {
  padding: 10px 16px;
  border-radius: 999px;
  text-decoration: none;
  color: var(--ink);
}

.section-nav a:hover {
  background: rgba(159, 28, 34, 0.08);
}

.section {
  margin-top: 28px;
}

.section-heading {
  margin-bottom: 18px;
}

.section-heading h2 {
  margin: 0;
  font-size: clamp(1.9rem, 4vw, 2.8rem);
  color: var(--primary-red-deep);
}

.overview-grid,
.period-overview,
.resource-grid,
.ai-layout,
.reflection-grid {
  display: grid;
  gap: 18px;
}

.overview-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.period-overview {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 18px;
}

.panel,
.period-card,
.timeline-period,
.resource-card,
.ai-action,
.reflection-card,
.extension-item {
  border-radius: var(--radius-lg);
}

.panel,
.timeline-period {
  padding: 24px;
}

.panel--order {
  background:
    linear-gradient(180deg, rgba(255, 250, 242, 0.98), rgba(251, 243, 231, 0.96)),
    linear-gradient(90deg, rgba(214, 163, 74, 0.1), transparent 36%);
}

.panel--focus {
  background:
    linear-gradient(180deg, rgba(255, 250, 242, 0.98), rgba(248, 238, 223, 0.96)),
    linear-gradient(90deg, rgba(159, 28, 34, 0.08), transparent 36%);
}

.panel__head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 18px;
}

.panel__head h3 {
  margin: 0;
  font-size: 1.24rem;
  color: var(--primary-red-deep);
}

.badge {
  font-size: 0.82rem;
}

.badge--gold {
  background: rgba(214, 163, 74, 0.16);
  color: #795616;
}

.badge--paper {
  background: rgba(159, 28, 34, 0.08);
  color: var(--primary-red);
}

.focus-stack {
  display: grid;
  gap: 14px;
}

.focus-card {
  padding: 18px;
  border-radius: var(--radius-md);
  background: rgba(255, 252, 247, 0.9);
  border: 1px solid rgba(159, 28, 34, 0.1);
}

.focus-card--accent {
  background: rgba(159, 28, 34, 0.06);
}

.focus-card h4,
.period-card h3,
.resource-card h3,
.reflection-card h3,
.extension-item h4,
.timeline-period h3,
.slide-stage__figure figcaption {
  margin: 0 0 12px;
}

.period-card {
  position: relative;
  padding: 22px;
  overflow: hidden;
}

.period-card::before {
  content: "";
  position: absolute;
  width: 130px;
  height: 130px;
  border-radius: 50%;
  inset: -42px auto auto -48px;
  background: radial-gradient(circle, rgba(214, 163, 74, 0.18), transparent 72%);
}

.period-card__index,
.timeline-period__index {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  color: #fff9ef;
  font-family: "STZhongsong", "Noto Serif SC", serif;
}

.period-card__index {
  margin-bottom: 14px;
  background: linear-gradient(135deg, var(--primary-red), var(--primary-red-bright));
}

.period-card__goal {
  color: var(--ink-soft);
  line-height: 1.8;
}

.tag {
  background: rgba(255, 248, 233, 0.96);
  color: var(--primary-red-deep);
  border: 1px solid rgba(214, 163, 74, 0.22);
  font-size: 0.82rem;
}

.timeline {
  display: grid;
  gap: 22px;
}

.timeline-period {
  position: relative;
  overflow: hidden;
}

.timeline-period::after {
  content: "";
  position: absolute;
  inset: auto 24px 0 24px;
  height: 4px;
  border-radius: 999px;
  background: linear-gradient(90deg, rgba(214, 163, 74, 0.28), transparent);
}

.timeline-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
}

.timeline-period__index {
  margin-bottom: 10px;
  background: linear-gradient(135deg, #9d2d2f, #cb5a3e);
}

.timeline-grid {
  display: grid;
  gap: 16px;
}

.timeline-activity {
  display: grid;
  grid-template-columns: minmax(180px, 220px) minmax(0, 1fr);
  gap: 18px;
  padding: 18px;
  border-radius: var(--radius-md);
  background: rgba(255, 252, 246, 0.92);
  border: 1px solid rgba(214, 163, 74, 0.16);
}

.timeline-activity__aside h4 {
  margin: 0 0 8px;
  color: var(--primary-red-deep);
  font-size: 1rem;
}

.timeline-details {
  display: grid;
  gap: 14px;
}

.timeline-details section {
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  background: rgba(248, 240, 226, 0.84);
}

.timeline-details section h5 {
  margin: 0 0 10px;
  color: var(--primary-red);
  font-size: 0.94rem;
}

.resource-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.resource-card {
  position: relative;
  overflow: hidden;
  padding: 22px;
}

.resource-card::before {
  content: "";
  position: absolute;
  inset: 0 auto auto 0;
  width: 100%;
  height: 6px;
  background: linear-gradient(90deg, var(--primary-red), var(--accent-gold));
}

.resource-card__top {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 14px;
}

.resource-type {
  display: inline-flex;
  align-items: center;
  white-space: nowrap;
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(159, 28, 34, 0.08);
  color: var(--primary-red);
  font-size: 0.84rem;
}

.resource-stage {
  margin-top: 10px;
  color: #7c6162;
  font-size: 0.92rem;
}

.resource-preview-note {
  margin-top: 14px;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  background: rgba(214, 163, 74, 0.12);
  color: #7b5818;
  font-size: 0.92rem;
  line-height: 1.7;
}

.inline-audio-list {
  display: grid;
  gap: 12px;
  margin-top: 16px;
}

.inline-audio-item {
  padding: 14px 16px;
  border-radius: var(--radius-md);
  background: rgba(255, 252, 247, 0.88);
  border: 1px solid rgba(159, 28, 34, 0.08);
}

.inline-audio-item strong {
  display: block;
  margin-bottom: 8px;
  color: var(--primary-red-deep);
}

.inline-audio-item audio {
  width: 100%;
}

.ai-layout {
  grid-template-columns: minmax(320px, 0.76fr) minmax(0, 1.24fr);
  align-items: start;
}

.ai-actions {
  display: grid;
  gap: 14px;
}

.ai-action {
  position: relative;
  padding: 18px;
  overflow: hidden;
}

.ai-action::before {
  content: "★";
  position: absolute;
  right: 16px;
  top: 12px;
  color: rgba(159, 28, 34, 0.08);
  font-size: 2rem;
}

.ai-action h3 {
  margin: 0 0 10px;
  color: var(--primary-red-deep);
  font-size: 1.06rem;
}

.ai-action p,
.ai-action ul {
  color: var(--ink-soft);
  line-height: 1.7;
}

.ai-action ul {
  margin: 0 0 18px;
  padding-left: 18px;
}

.ai-action button {
  width: 100%;
  padding: 12px 16px;
}

.ai-output textarea {
  width: 100%;
  min-height: 320px;
  resize: vertical;
  padding: 18px;
  border-radius: var(--radius-md);
  border: 1px solid rgba(159, 28, 34, 0.16);
  background: rgba(255, 253, 249, 0.98);
  font: inherit;
  line-height: 1.8;
}

.ai-output textarea:focus {
  outline: 2px solid rgba(159, 28, 34, 0.18);
  outline-offset: 2px;
}

.ai-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 16px 0 14px;
}

.ai-meta__item {
  min-width: 140px;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  background: rgba(214, 163, 74, 0.14);
}

.ai-meta__item span {
  display: block;
  margin-bottom: 6px;
  color: #7b5818;
  font-size: 0.84rem;
}

.prompt-box {
  margin-top: 16px;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  background: rgba(245, 236, 220, 0.82);
}

.prompt-box summary {
  cursor: pointer;
  color: var(--primary-red);
}

.prompt-box pre {
  margin: 14px 0 0;
  white-space: pre-wrap;
  font-family: "Cascadia Code", "Consolas", monospace;
  line-height: 1.7;
}

.reflection-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.reflection-card,
.extension-item {
  padding: 22px;
}

.reflection-card {
  position: relative;
  overflow: hidden;
}

.reflection-card::before {
  content: "";
  position: absolute;
  inset: 0 auto auto 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--accent-gold), transparent);
}

.extension-panel {
  margin-top: 18px;
}

.extension-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.extension-item {
  list-style: none;
}

.page-footer {
  margin-top: 28px;
  padding: 18px 22px;
  border-radius: var(--radius-lg);
  background: rgba(255, 250, 242, 0.96);
  border: 1px solid var(--line);
}

.music-dock {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 40;
  display: grid;
  gap: 10px;
  min-width: 248px;
  padding: 14px 16px;
  border-radius: 20px;
  background: rgba(255, 250, 242, 0.97);
  border: 1px solid rgba(159, 28, 34, 0.14);
  box-shadow: 0 20px 38px rgba(63, 7, 11, 0.18);
}

.music-dock__meta span {
  display: block;
  margin-bottom: 4px;
  color: var(--primary-red);
  font-size: 0.84rem;
}

.music-dock__meta strong {
  color: var(--ink);
  font-family: "STZhongsong", "Noto Serif SC", serif;
  font-size: 1rem;
}

.music-dock__buttons {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.music-dock__button {
  appearance: none;
  border: 1px solid rgba(159, 28, 34, 0.16);
  border-radius: 999px;
  padding: 10px 14px;
  background: rgba(255, 251, 245, 0.96);
  color: var(--ink);
  cursor: pointer;
  font: inherit;
}

.music-dock__button--primary {
  border-color: transparent;
  background: linear-gradient(135deg, var(--primary-red), var(--primary-red-bright));
  color: #fff8ef;
}

.music-dock__button:hover {
  box-shadow: 0 10px 20px rgba(98, 18, 18, 0.12);
}

.modal[hidden] {
  display: none;
}

.modal {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: grid;
  place-items: center;
}

.modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(24, 13, 13, 0.58);
  backdrop-filter: blur(4px);
}

.modal__dialog {
  position: relative;
  z-index: 1;
  width: min(1180px, calc(100vw - 24px));
  max-height: min(90vh, 960px);
  overflow: auto;
  padding: 26px;
  border-radius: var(--radius-xl);
}

.modal__close {
  position: absolute;
  top: 14px;
  right: 16px;
  width: 40px;
  height: 40px;
  border: none;
  border-radius: 50%;
  background: rgba(159, 28, 34, 0.08);
  color: var(--primary-red-deep);
  font-size: 1.4rem;
  cursor: pointer;
}

.modal__header {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 20px;
  padding-right: 48px;
}

.modal__body {
  display: grid;
  gap: 16px;
}

.preview-section,
.preview-callout,
.preview-links,
.preview-audio-card {
  padding: 18px;
  border-radius: var(--radius-md);
  background: rgba(255, 252, 246, 0.92);
  border: 1px solid rgba(159, 28, 34, 0.1);
}

.preview-section h4,
.preview-callout h4,
.preview-links h4,
.preview-audio-card h4 {
  margin: 0 0 12px;
  color: var(--primary-red-deep);
  font-size: 1rem;
}

.preview-links__grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.preview-audio-card audio {
  width: 100%;
  margin-top: 12px;
}

.pdf-frame {
  width: 100%;
  min-height: 60vh;
  border: 1px solid rgba(159, 28, 34, 0.16);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.9);
}

.slide-viewer {
  display: grid;
  grid-template-columns: minmax(170px, 200px) minmax(0, 1fr);
  gap: 18px;
}

.slide-sidebar {
  display: grid;
  gap: 12px;
  align-content: start;
}

.slide-sidebar__head,
.slide-stage__toolbar,
.slide-stage__hint {
  padding: 12px 14px;
  border-radius: var(--radius-md);
  background: rgba(248, 240, 226, 0.86);
  border: 1px solid rgba(159, 28, 34, 0.08);
}

.slide-sidebar__head strong,
.slide-stage__toolbar strong {
  display: block;
  color: var(--primary-red-deep);
}

.slide-sidebar__head span,
.slide-stage__toolbar span,
.slide-stage__hint {
  color: var(--ink-soft);
  font-size: 0.92rem;
  line-height: 1.7;
}

.slide-thumbs {
  display: grid;
  gap: 10px;
  max-height: 62vh;
  overflow: auto;
  padding-right: 4px;
}

.slide-thumb {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  gap: 10px;
  align-items: center;
  width: 100%;
  padding: 8px;
  border-radius: var(--radius-md);
  text-align: left;
}

.slide-thumb img {
  width: 58px;
  height: 40px;
  object-fit: cover;
  border-radius: 8px;
  border: 1px solid rgba(159, 28, 34, 0.08);
}

.slide-thumb span {
  color: var(--ink);
  font-size: 0.92rem;
}

.slide-thumb.is-active {
  background: rgba(159, 28, 34, 0.12);
  border-color: rgba(159, 28, 34, 0.28);
}

.slide-stage {
  display: grid;
  gap: 14px;
}

.slide-stage__toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.slide-nav {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.slide-stage__figure {
  margin: 0;
  padding: 18px;
  border-radius: var(--radius-lg);
  background: rgba(255, 253, 248, 0.98);
  border: 1px solid rgba(159, 28, 34, 0.1);
  box-shadow: inset 0 0 0 1px rgba(214, 163, 74, 0.12);
}

.slide-stage__figure img {
  display: block;
  width: 100%;
  border-radius: var(--radius-md);
  background: #fff;
}

.slide-stage__figure figcaption {
  margin-top: 12px;
  color: var(--ink-soft);
}

.slide-empty {
  padding: 20px;
  border-radius: var(--radius-lg);
  background: rgba(248, 240, 226, 0.9);
  border: 1px solid rgba(159, 28, 34, 0.12);
}

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 1060px) {
  .hero-poster,
  .overview-grid,
  .period-overview,
  .resource-grid,
  .ai-layout,
  .reflection-grid,
  .slide-viewer {
    grid-template-columns: 1fr;
  }

  .timeline-activity {
    grid-template-columns: 1fr;
  }

  .slide-thumbs {
    grid-template-columns: repeat(5, minmax(120px, 1fr));
    max-height: none;
    overflow-x: auto;
    overflow-y: hidden;
  }
}

@media (max-width: 760px) {
  .page-shell {
    width: min(calc(100vw - 16px), 1220px);
    padding-top: 16px;
  }

  .hero-poster,
  .panel,
  .timeline-period,
  .resource-card,
  .reflection-card,
  .extension-item,
  .modal__dialog {
    padding: 18px;
  }

  .hero-poster h1 {
    font-size: 2.46rem;
    white-space: normal;
  }

  .hero__actions,
  .modal__actions,
  .resource-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .panel__head,
  .timeline-head,
  .modal__header,
  .slide-stage__toolbar {
    flex-direction: column;
    align-items: flex-start;
  }

  .extension-list,
  .resource-grid {
    grid-template-columns: 1fr;
  }

  .section-nav {
    border-radius: 22px;
  }

  .section-nav a {
    flex: 1 1 calc(50% - 10px);
    text-align: center;
  }

  .slide-thumbs {
    grid-template-columns: repeat(3, minmax(120px, 1fr));
  }

  .music-dock {
    left: 12px;
    right: 12px;
    bottom: 12px;
    min-width: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .reveal,
  .action-pill,
  .ghost-button,
  .resource-actions button,
  .resource-actions a,
  .ai-action button,
  .slide-nav button,
  .slide-thumb {
    transition: none;
  }
}