/* ==================== 02. 顶部导航：品牌、菜单、搜索和手机菜单按钮 ==================== */
.site-header {
  position: fixed; z-index: 100; top: 0; left: 0; right: 0; height: var(--layout-header-height); padding: 0 4.5vw;
  display: grid; grid-template-columns: minmax(13.75rem, 1fr) auto minmax(6.25rem, 1fr); align-items: center;
  background: var(--color-navigation-surface); border-bottom: 1px solid var(--color-rule); backdrop-filter: blur(0.875rem);
}
.brand { display: flex; align-items: center; gap: 0.75rem; width: max-content; }
.brand-seal { position: relative; width: 2.5rem; height: 2.5rem; display: grid; place-items: center; color: #f5eee2; background: #a8332a; border: 1.5px solid #f5eee2; border-radius: 3px; font: 700 1.4375rem var(--serif); }
.brand-seal::after { content: ""; position: absolute; inset: 0.22rem; border: 1px dashed rgba(245, 238, 226, .88); border-radius: 1px; pointer-events: none; }
.brand-logo-image { width: 100%; height: 100%; display: block; object-fit: contain; border: 0; border-radius: inherit; }
.brand-seal:has(.brand-logo-image:not([hidden])) { padding: 0; background: transparent; border: 0; }
.brand-seal:has(.brand-logo-image:not([hidden]))::after { display: none; }
.brand-logo-fallback[hidden] { display: none; }
.brand strong { display: block; font: 700 1.125rem var(--serif); }
.brand small { display: block; margin-top: 3px; color: var(--muted); font-size: 0.5625rem; }
.main-nav { display: flex; align-items: center; gap: clamp(.8rem, 1.35vw, 1.45rem); height: 100%; }
.main-nav a,
.footer-links a { font-family: var(--font-body); font-weight: 500; }
.main-nav a { position: relative; display: grid; place-items: center; height: 100%; color: #45423d; font-size: var(--text-nav); white-space: nowrap; }
.main-nav a::after { content: ""; position: absolute; bottom: 0; left: 50%; width: 0; height: 3px; background: var(--red); transform: translateX(-50%); transition: width .25s; }
.main-nav a:hover::after, .main-nav a.active::after { width: 1.75rem; }
.header-actions { justify-self: end; display: flex; align-items: center; gap: .25rem; }
.header-clock { min-width: 4.7rem; padding-inline: .45rem; color: var(--color-ink-muted); border-left: 1px solid var(--color-rule); font: 600 var(--text-header-clock)/1 var(--font-body); text-align: center; white-space: nowrap; font-variant-numeric: tabular-nums; }
.search-button, .music-button, .settings-button { min-height: 2.75rem; color: var(--color-ink); border: 1px solid transparent; background: transparent; cursor: var(--cursor-pointer) !important; transition: color var(--motion-header-tool-hover) var(--ease-out), border-color var(--motion-header-tool-hover) var(--ease-out), background-color var(--motion-header-tool-hover) var(--ease-out); }
.search-button { padding: 0 .7rem; display: flex; align-items: center; gap: 0.3125rem; }
.search-button span:first-child { font: 1.625rem Georgia, serif; transform: rotate(-18deg); }
.music-button { width: 2.75rem; height: 2.75rem; display: grid; place-items: center; padding: 0; color: var(--color-ink-muted); font: 1.45rem/1 Georgia, serif; }
.settings-button { width: 2.75rem; height: 2.75rem; display: grid; place-items: center; padding: 0; }
.search-button:hover, .settings-button:hover, .settings-button[aria-expanded="true"] { color: var(--color-accent); }
.music-button[data-playing="true"] { color: var(--color-accent); border-color: var(--color-rule); background: var(--color-paper-deep); }
.music-button[data-video-paused="true"] { color: var(--color-ink-muted); opacity: .7; }
.search-button:active, .music-button:active, .settings-button:active { color: var(--color-accent-dark); background: var(--color-paper-deep); }
.search-button:focus-visible, .music-button:focus-visible, .settings-button:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 2px; }
.menu-toggle { display: none; }

/* ==================== 03. 首页首屏：标题、按钮、统计数字和封泥主视觉 ==================== */
.hero { min-height: 100vh; padding: 7.75rem 8vw 5.25rem; display: grid; grid-template-columns: .9fr 1.1fr; align-items: center; position: relative; overflow: hidden; background: var(--section-bg); border-bottom: 1px solid var(--line); }
.hero::after { content: ""; position: absolute; inset: 4.75rem 0 0 49%; opacity: .22; background-image: linear-gradient(rgba(36,35,33,.16) 1px, transparent 1px), linear-gradient(90deg, rgba(36,35,33,.12) 1px, transparent 1px); background-size: 3.25rem 3.25rem; mask-image: linear-gradient(90deg, transparent, black 18%, black); }
.hero-copy { position: relative; z-index: 2; max-width: 36.875rem; padding-right: 6vw; }
.eyebrow { margin: 0 0 1.125rem; color: var(--red); font-weight: 700; font-size: clamp(.95rem, .25vw + .88rem, 1.08rem); line-height: 1.5; letter-spacing: 0; }
.eyebrow::before { content: ""; display: inline-block; width: 1.75rem; height: 1px; margin-right: 0.625rem; vertical-align: middle; background: currentColor; }
.eyebrow.light { color: #d4b09a; }
.hero h1 { margin: 0; font: 700 clamp(4rem, 7vw, 7rem)/1 var(--serif); }
.hero-lead { max-width: 32.1875rem; margin: 1.875rem 0; color: #55514b; font: 500 1.125rem/1.9 var(--serif); }
.hero-actions { display: flex; align-items: center; gap: 1.5rem; }
.button { min-height: 3rem; padding: 0 1.375rem; display: inline-flex; align-items: center; justify-content: center; gap: 1.875rem; border: 0; border-radius: 2px; cursor: pointer; font-weight: 600; font-size: 0.875rem; transition: transform .25s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow .25s ease; }
.button.primary { color: #fff; background: var(--red); box-shadow: 0 0.75rem 1.625rem rgba(116,35,31,.2); transition: background .25s ease, transform .25s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow .25s ease; }
.button.primary:hover {
  background: var(--red-dark);
  transform: translateY(-2px);
  box-shadow: 0 1rem 2rem rgba(116,35,31,.3), 0 0.25rem 0.5rem rgba(0, 0, 0, 0.1);
}
.button.primary:active {
  transform: translateY(0);
  box-shadow: 0 0.5rem 1rem rgba(116,35,31,.2);
}
.text-button { padding: 0; border-bottom: 1px solid var(--ink); }
.hero-stats { display: flex; gap: 2.25rem; margin: 3rem 0 0; }
.hero-stats div { min-width: 4.875rem; padding-left: 0.875rem; border-left: 1px solid var(--line); }
.hero-stats dt { font: 600 1.5625rem var(--serif); }
.hero-stats dd { margin: 0.25rem 0 0; color: var(--muted); font-size: 0.6875rem; }
.hero-object { position: relative; z-index: 2; height: min(66vw, 40.625rem); display: grid; place-items: center; }
.relic-disc { position: relative; display: grid; place-items: center; background: #8d5948; clip-path: polygon(6% 24%, 13% 9%, 31% 4%, 46% 8%, 63% 3%, 82% 11%, 96% 29%, 94% 50%, 99% 69%, 85% 90%, 68% 96%, 49% 91%, 30% 98%, 11% 86%, 4% 66%, 8% 48%); box-shadow: inset 1.375rem 1.125rem 1.5625rem rgba(255,225,190,.14), inset -1.375rem -1.125rem 1.875rem rgba(54,24,18,.25); }
.relic-disc::before { content: ""; position: absolute; inset: 13%; border: 0.3125rem ridge rgba(58,26,20,.45); }
.mini-inscription { position: relative; z-index: 2; width: 57%; display: grid; grid-template-columns: 1fr 1fr; gap: 3px; color: rgba(60,24,18,.72); font: 700 clamp(2.625rem, 5vw, 4.5rem)/1 var(--serif); text-shadow: 1px 1px rgba(255,210,180,.18); }
.mini-inscription span { display: grid; place-items: center; aspect-ratio: 1; }
.scroll-cue { position: absolute; z-index: 3; left: 8vw; bottom: 1.75rem; display: flex; align-items: center; gap: .9rem; color: #6f6961; font-size: .78rem; }
.scroll-cue i { position: relative; width: 1rem; height: 2.75rem; border: 0; border-radius: 0; }
.scroll-cue i::before { content: ""; position: absolute; left: 50%; top: 0; width: 1px; height: 2.15rem; background: rgba(36,35,33,.48); transform: translateX(-50%); }
.scroll-cue i::after { content: ""; position: absolute; left: 50%; bottom: .2rem; width: .55rem; height: .55rem; border-right: 1px solid rgba(36,35,33,.62); border-bottom: 1px solid rgba(36,35,33,.62); transform: translateX(-50%) rotate(45deg); }

/* ==================== 04. 公共内容容器和“我们的工作”板块 ==================== */
.section-shell { width: min(var(--layout-content-max), var(--layout-content-width)); margin: 0 auto; }
.intro { padding: 6.875rem 0 6.25rem; background: var(--section-bg); }
.section-heading h2 { margin: 0; font: 600 clamp(2.125rem, 4vw, 3.4375rem)/1.38 var(--serif); }
.compact-heading { max-width: none; }
.compact-heading h2 { white-space: nowrap; }

/* ==================== 05. 认识封泥与封泥故事板块 ==================== */
/* 两个板块共用纸本文字和编号风格。数字手卷的详细样式在文件后部。 */
.knowledge, .stories { padding: 7rem 0; background: var(--section-bg); }
.story-grid { margin-top: 3.25rem; display: grid; grid-template-columns: repeat(2, 1fr); border-top: 1px solid var(--line); border-left: 1px solid var(--line); }
.story-card { min-width: 0; min-height: 16rem; padding: 1.8rem; display: grid; grid-template-columns: 3.2rem 1fr; gap: 1.25rem; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); background: var(--color-paper-soft); }
.story-card small { color: var(--red); font-size: .75rem; font-weight: 700; }
.story-card h3 { margin: .8rem 0 .7rem; font: 600 clamp(1.4rem, 2vw, 1.8rem)/1.5 var(--serif); }
.story-card p { margin: 0; color: var(--muted); font-size: .88rem; line-height: 1.9; }

/* ==================== 07. 文化地图、地点详情和资料索引板块 ==================== */
.map-section { padding: 6.5625rem 0; color: var(--ink); background: var(--color-paper); }
.map-heading { display: flex; align-items: end; justify-content: space-between; gap: 2.5rem; }
.map-heading h2 { color: var(--ink); }
.map-heading > p { max-width: 24rem; margin: 0 0 0.5rem; color: var(--muted); font-size: .95rem; line-height: 1.8; }
.map-toolbar { display: flex; align-items: center; gap: 0.5625rem; margin: 2rem 0 1.25rem; padding: .3rem; background: rgba(53,95,87,.075); }
.map-toolbar-spacer { position: relative; flex: 1 1 auto; min-width: 1rem; }
/* 桌面端把分隔线放在两组按钮之间的空白正中，左右视觉留白保持一致。 */
.map-toolbar-spacer::after { content: ""; position: absolute; left: 50%; top: 0; width: 1px; height: 100%; background: var(--line); transform: translateX(-50%); }
.map-mode-switch { display: flex; flex: 0 0 auto; gap: .35rem; }
.map-mode-button { white-space: nowrap; }
.filter-chip { padding: .65rem 1.15rem; color: var(--green-dark); border: 1px solid rgba(41,62,56,.25); border-radius: 2px; background: transparent; cursor: pointer; font-size: .9rem; }
.filter-chip.active, .filter-chip:hover { color: #302821; background: #d8c6ae; border-color: #d8c6ae; }
/* 桌面端地图与介绍框固定同高，地点说明长短不会再改变整个模块尺寸。 */
.map-layout { height: var(--layout-map-panel-height); min-height: 0; display: grid; grid-template-columns: 1.65fr .7fr; margin-top: .4rem; border: 1px solid rgba(36,59,53,.2); box-shadow: 0 2rem 4.5rem rgba(35,48,42,.12); }
.shandong-map { position: relative; height: 100%; min-height: 0; overflow: hidden; background-color: #183a34; background-image: radial-gradient(circle at 50% 45%, rgba(103,145,132,.12), transparent 42%), linear-gradient(135deg, #244941, #132f2b); background-size: 2.75rem 2.75rem; }
.shandong-terrain-canvas { position: absolute; z-index: 1; inset: 0; width: 100%; height: 100%; display: block; pointer-events: none; }
.shandong-flat-map-image { position: absolute; z-index: 1; inset: 0; width: 100%; height: 100%; display: none; object-fit: contain; object-position: center; }
.shandong-map[data-map-mode="flat"] .shandong-flat-map-image { display: block; }
.shandong-map[data-map-mode="flat"] .shandong-terrain-canvas { visibility: hidden; }
.shandong-map[data-map-mode="flat"] .map-terrain-controls,
.shandong-map[data-map-mode="flat"] .map-rotation-control,
.shandong-map[data-map-mode="flat"] .map-terrain-status { display: none; }
.shandong-map[data-map-mode="flat"] { background: transparent; background-image: none; }
.shandong-map[data-map-mode="flat"]::before,
.shandong-map[data-map-mode="flat"] .map-watermark,
.shandong-map[data-map-mode="flat"] .map-routes { display: none; }
.shandong-map[data-map-mode="flat"] .map-legend { display: none; }
.shandong-map[data-map-mode="flat"] .map-legend { color: rgba(55,45,38,.76); text-shadow: 0 1px 2px rgba(255,255,255,.7); }
.shandong-map[data-map-mode="flat"] .map-legend span:first-child i { background: #a8332a; }
.shandong-map.has-three-terrain { cursor: grab; touch-action: none; }
.shandong-map.has-three-terrain.is-dragging { cursor: grabbing; }
.shandong-map.has-three-terrain::before,
.shandong-map.has-three-terrain .map-watermark,
.shandong-map.has-three-terrain .map-routes { opacity: 0; }
.map-terrain-status { position: absolute; z-index: 4; top: 1rem; left: 1.25rem; margin: 0; color: var(--color-dark-muted); font-size: var(--text-xs); pointer-events: none; }
.map-terrain-controls { position: absolute; z-index: 6; top: 1rem; right: 1rem; display: grid; border: var(--rule-hairline) solid color-mix(in oklch, var(--color-dark-ink) 22%, transparent); background: color-mix(in oklch, var(--color-dark-surface) 88%, transparent); }
.map-terrain-controls button { width: 2.75rem; height: 2.75rem; padding: 0; color: var(--color-dark-ink); border: 0; background: transparent; font-size: 1.15rem; }
.map-terrain-controls button:hover { color: var(--color-accent-ink); background: var(--color-accent); }
.map-rotation-control {
  position: absolute; z-index: 6; right: 1rem; top: 50%; width: 2.75rem; height: 12rem;
  padding: .55rem .35rem; display: grid; grid-template-rows: auto minmax(0, 1fr) auto; justify-items: center; gap: .35rem;
  color: var(--color-dark-muted); border: 1px solid rgba(238,232,221,.18); background: rgba(24,48,43,.82);
  font-size: .625rem; transform: translateY(-50%);
}
.map-rotation-control input {
  width: 1rem; height: 100%; margin: 0; padding: 0;
  writing-mode: vertical-lr; direction: rtl; accent-color: var(--color-map-marker); cursor: ns-resize;
}
.map-rotation-control output { min-width: 2rem; color: var(--color-dark-ink); text-align: center; font-variant-numeric: tabular-nums; }
.shandong-map::before { content: ""; position: absolute; inset: 13% 11%; background: #5e766d; clip-path: polygon(3% 54%, 9% 34%, 24% 33%, 29% 18%, 43% 24%, 53% 12%, 66% 20%, 75% 11%, 83% 27%, 98% 35%, 87% 47%, 91% 61%, 74% 66%, 67% 82%, 51% 77%, 42% 92%, 30% 77%, 15% 80%, 17% 65%); box-shadow: inset 0 0 3.75rem rgba(0,0,0,.16); }
.map-watermark { position: absolute; z-index: 1; left: 32%; top: 39%; color: rgba(255,255,255,.05); font: 700 5.375rem var(--serif); }
.map-routes i { position: absolute; z-index: 2; height: 1px; transform-origin: left; background: rgba(224,211,190,.22); }
.map-routes i:nth-child(1) { width: 30%; left: 38%; top: 42%; transform: rotate(18deg); }
.map-routes i:nth-child(2) { width: 24%; left: 35%; top: 60%; transform: rotate(-32deg); }
.map-routes i:nth-child(3) { width: 37%; left: 48%; top: 50%; transform: rotate(-24deg); }
.map-marker { position: absolute; z-index: 4; width: 1.25rem; height: 1.25rem; margin: -0.625rem 0 0 -0.625rem; border: 0; border-radius: 50%; background: rgba(211,183,147,.26); cursor: pointer; }
.map-marker i { position: absolute; inset: 0.375rem; border-radius: 50%; background: #ead3b4; transition: transform .2s; }
.map-marker::before { content: ""; position: absolute; inset: 1px; border: 1px solid #d8b990; border-radius: 50%; }
.map-marker span { position: absolute; left: 1.0625rem; top: -3px; width: max-content; color: #eef1ef; font-size: 0.6875rem; text-shadow: 0 1px 0.25rem #20312c; }
.map-marker.active i, .map-marker:hover i { background: #d55a48; transform: scale(1.5); }
.shandong-map[data-map-mode="flat"] .map-marker {
  background: rgba(190, 151, 99, .28);
}
.shandong-map[data-map-mode="flat"] .map-marker::before { border-color: #c4a275; }
.shandong-map[data-map-mode="flat"] .map-marker i { background: #d4b17a; }
.shandong-map[data-map-mode="flat"] .map-marker:is(.active, :hover, :focus-visible) { z-index: 8; }
.shandong-map[data-map-mode="flat"] .map-marker:is(.active, :hover, :focus-visible) i { background: #c87964; }
.shandong-map[data-map-mode="flat"] .map-marker span {
  left: 50%; top: auto; bottom: calc(100% + 6px); transform: translateX(-50%);
  color: #77614d; font-size: 12px; line-height: 1.5;
  text-shadow: 0 1px 2px #ffffff;
  pointer-events: none;
}
@media (max-width: 640px) {
  .shandong-map[data-map-mode="flat"] .map-marker {
    width: 12px; height: 12px; margin: -6px 0 0 -6px;
  }
  .shandong-map[data-map-mode="flat"] .map-marker i { inset: 2px; }
}
.map-legend { position: absolute; z-index: 4; left: 1.25rem; right: 1.25rem; bottom: 1.125rem; display: flex; flex-wrap: wrap; align-items: end; justify-content: space-between; gap: .35rem .75rem; color: #aebbb6; font-size: 0.625rem; }
.map-caption { margin-left: auto; text-align: right; }
/* 精度说明独占一行，窄屏可自然换行，不挤压点位图例和图谱名称。 */
.map-accuracy-note { flex-basis: 100%; font: inherit; line-height: 1.5; text-align: right; }
.map-legend span:first-child i { display: inline-block; width: 0.4375rem; height: 0.4375rem; margin-right: 0.4375rem; border-radius: 50%; background: #ead3b4; }
.site-panel { height: 100%; min-height: 0; padding: 2.375rem 2.125rem; display: grid; grid-template-rows: auto auto auto minmax(0, 1fr) auto auto; background: var(--color-paper); color: var(--ink); overflow: hidden; }
.panel-kicker { display: flex; align-items: center; justify-content: space-between; padding-bottom: 1.25rem; border-bottom: 1px solid var(--line); color: var(--red); font-size: .9rem; }
.panel-kicker span:first-child { font: 700 2.25rem Georgia, serif; }
.site-city { margin: 3.125rem 0 0.625rem; color: var(--red); font-weight: 700; font-size: 0.75rem; }
.site-panel h3 { margin: 0; font: 600 clamp(1.75rem, 2vw, 2.15rem)/1.42 var(--serif); }
#siteDescription { min-height: 0; margin: 1rem 0; padding-right: .5rem; color: var(--muted); font-size: .95rem; line-height: 1.9; overflow-y: auto; overscroll-behavior: contain; scrollbar-width: thin; scrollbar-color: var(--color-rule-strong) transparent; }
#siteDescription::-webkit-scrollbar { width: .35rem; }
#siteDescription::-webkit-scrollbar-thumb { background: var(--color-rule-strong); }
.site-meta { margin: 1.25rem 0 1.75rem; }
.site-meta div { display: flex; justify-content: space-between; padding: 0.6875rem 0; border-bottom: 1px solid var(--line); font-size: 0.75rem; }
.site-meta dt { color: var(--muted); }
.site-meta dd { margin: 0; font-weight: 600; }
.panel-link { padding: 0.8125rem 0; display: flex; justify-content: space-between; border: 0; border-bottom: 1px solid var(--ink); background: transparent; cursor: pointer; font-weight: 600; }

.collection { padding: 6.875rem 0; background: var(--section-bg); }
.split-heading { display: flex; align-items: end; justify-content: space-between; gap: 1.875rem; }
.split-heading h2 { max-width: 42.5rem; }
.split-heading > a { padding-bottom: 0.5rem; border-bottom: 1px solid var(--ink); font-size: 0.8125rem; }
.heading-note { max-width: 25rem; margin: 0 0 .5rem; color: var(--muted); font-size: .78rem; line-height: 1.8; }
.collection-grid { margin-top: 3.25rem; display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.125rem; }
.relic-card { min-width: 0; background: var(--color-paper-soft); border-bottom: 2px solid transparent; transition: transform .35s cubic-bezier(0.34, 1.56, 0.64, 1), border-color .35s ease, box-shadow .35s ease; }
.relic-card:hover {
  transform: translateY(-0.5rem);
  border-color: var(--red);
  box-shadow: 0 1.25rem 2.5rem rgba(168, 51, 42, 0.15), 0 0.5rem 1rem rgba(0, 0, 0, 0.1);
}
.relic-visual { position: relative; height: 17.8125rem; display: grid; place-items: center; overflow: hidden; background-color: #d4cabb; background-image: radial-gradient(rgba(255,255,255,.25) 1px, transparent 1px); background-size: 0.4375rem 0.4375rem; }
.relic-visual.ink { background-color: #b8c0b8; }
.relic-visual.bronze { background-color: #aebbb1; }
.relic-visual.sand { background-color: #d0bca8; }
.relic-disc { width: 68%; aspect-ratio: 1; transform: rotate(-5deg); filter: drop-shadow(0.625rem 0.875rem 0.75rem rgba(44,31,25,.25)); }
.ink .relic-disc { background: #6b5d54; transform: rotate(8deg); }
.bronze .relic-disc { background: #765f4d; }
.sand .relic-disc { background: #9a6751; transform: rotate(5deg); }
.mini-inscription { width: 56%; font-size: 2.125rem; }
.relic-code { position: absolute; left: 1rem; bottom: .85rem; color: rgba(36,35,33,.7); font: 700 .88rem Georgia, serif; }
.relic-info { padding: 1.25rem; }
.relic-info > div { display: flex; gap: .65rem; color: var(--red); font-size: .82rem; font-weight: 700; }
.relic-info h3 { margin: .8rem 0 .65rem; font: 600 clamp(1.35rem, 1.35vw, 1.6rem) var(--serif); }
.relic-info p { min-height: 5.3rem; margin: 0; color: var(--muted); font-size: .88rem; line-height: 1.8; }
.relic-info button { width: 100%; margin-top: 0.875rem; padding: 0.75rem 0 0; display: flex; justify-content: space-between; border: 0; border-top: 1px solid var(--line); background: transparent; cursor: pointer; font-size: 0.6875rem; }
.empty-state { grid-column: 1/-1; padding: 4.375rem; text-align: center; border: 1px solid var(--line); }

main > section + section { border-top: 1px solid rgba(36, 35, 33, .14); }

.site-footer { padding: 3.125rem 5vw 1.875rem; display: grid; grid-template-columns: 1fr auto; gap: 2.8125rem; color: var(--color-ink); background: var(--color-navigation-surface); border-top: var(--rule-hairline) solid var(--color-rule); }
.footer-brand { display: flex; align-items: center; gap: 0.9375rem; }
.footer-brand strong { font: 600 1.25rem var(--serif); }
.footer-brand p { margin: 0.3125rem 0 0; color: var(--color-ink-muted); font-size: 0.6875rem; }
.footer-links { display: flex; align-items: center; gap: 1.875rem; color: var(--color-ink-muted); font-size: 0.75rem; }
.footer-compliance { grid-column: 1/-1; display: grid; gap: .4rem; }
.footer-contact,
.footer-icp,
.copyright { margin: 0; color: var(--color-ink-muted); font-size: .75rem; }
.footer-contact a,
.footer-icp a { color: var(--color-accent-dark); font-weight: 600; text-decoration: underline; text-underline-offset: .2em; }
.footer-contact a:hover,
.footer-icp a:hover { color: var(--color-accent); }
.footer-icp a:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 2px; }
.copyright { margin: 0; padding-top: .15rem; color: var(--color-ink-muted); font-size: 0.6875rem; }

/* 搜索弹窗：限制最大高度，内容过多时只滚动弹窗内部。 */
.search-dialog { width: min(45rem, 90vw); max-height: min(42rem, 88vh); padding: 0; border: 0; background: transparent; overflow: visible; }
.search-dialog::backdrop { background: rgba(25,28,27,.75); }
.search-box { position: relative; max-height: min(42rem, 88vh); padding: 3.125rem; overflow: auto; background: var(--paper); will-change: transform, opacity; }
.search-dialog.is-closing .search-box { pointer-events: none; }
.dialog-close { position: absolute; z-index: 2; right: 1rem; top: 0.875rem; width: max(2.75rem, 44px); height: max(2.75rem, 44px); display: grid; place-items: center; border: 1px solid transparent; background: transparent; cursor: pointer; font-size: 1.5625rem; line-height: 1; transition: color var(--dur-short) var(--ease-out), border-color var(--dur-short) var(--ease-out), background-color var(--dur-short) var(--ease-out); }
.dialog-close:hover { color: var(--color-accent); border-color: var(--color-rule); background: var(--color-paper-deep); }
.search-box label { display: block; margin: 0 0 1.75rem; font: 600 1.875rem var(--serif); }
.search-row { display: grid; grid-template-columns: minmax(0, 1fr) 5rem; align-items: stretch; gap: .75rem; }
/* 输入框与清除按钮叠放；按钮只在存在搜索文字时显示。 */
.search-input-wrap { position: relative; min-width: 0; display: grid; align-items: center; border: 1px solid var(--color-rule-strong); border-radius: var(--radius-control); background: var(--color-paper-soft); transition: border-color var(--dur-short) var(--ease-out), box-shadow var(--dur-short) var(--ease-out); }
.search-input-wrap:focus-within { border-color: var(--color-focus); box-shadow: 0 0 0 2px color-mix(in oklch, var(--color-focus) 24%, transparent); }
.search-row input { width: 100%; min-width: 0; padding: 0.8125rem 3rem 0.8125rem 3px; border: 0; outline: 0; background: transparent; }
.search-row input::-webkit-search-cancel-button,
.source-index-head input::-webkit-search-cancel-button { display: none; }
.search-clear { position: absolute !important; right: 0.25rem; width: max(2.5rem, 44px); height: max(2.5rem, 44px); padding: 0; display: grid; place-items: center; color: var(--color-ink-muted) !important; border: 1px solid transparent !important; background: transparent !important; font-size: 1.25rem; line-height: 1; }
.search-clear[hidden],
.source-search-clear[hidden] { display: none; }
.search-clear:hover { color: var(--color-accent) !important; border-color: var(--color-rule) !important; background: var(--color-paper-deep) !important; }
.search-input-wrap.is-cleared,
.source-search-wrap.is-cleared { animation: search-cleared 420ms var(--ease-out); }
.search-row button { color: #fff; border: 0; background: var(--red); cursor: pointer; }
.search-results { max-height: 16.25rem; margin-top: 1.5625rem; overflow: auto; }
.search-results > p { color: var(--muted); font-size: 0.75rem; }
.search-results button { width: 100%; min-height: 3.5rem; padding: 0.8125rem 0.5rem; display: flex; align-items: center; justify-content: space-between; gap: 1rem; text-align: left; border: 0; border-bottom: 1px solid var(--line); background: transparent; cursor: pointer; transition: color var(--dur-short) var(--ease-out), background-color var(--dur-short) var(--ease-out); }
.search-results button:hover { color: var(--color-accent-dark); background: var(--color-paper-deep); }
.search-results button strong { min-width: 0; overflow-wrap: anywhere; }
.search-results button span { color: var(--muted); font-size: 0.6875rem; }
.search-result-group + .search-result-group { margin-top: var(--space-md); }
.search-result-group h3 { margin: 0; padding: 0.625rem 0; display: flex; justify-content: space-between; color: var(--color-ink-muted); border-bottom: 1px solid var(--color-rule); font: 600 0.75rem var(--font-body); }
.search-result-group h3 span { min-width: 1.5rem; text-align: right; color: var(--color-accent); }
.dialog-close:focus-visible, .search-clear:focus-visible, .search-row > button:focus-visible, .search-results button:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 2px; }
/* 点击搜索结果后，让对应藏品或图录条目短暂描边，帮助用户确认跳转位置。 */
.relic-card.search-target, .source-index article.search-target { animation: search-target var(--effect-search-highlight-duration) var(--ease-out); }
@keyframes search-cleared { 0% { background: var(--color-cinnabar-soft); } 100% { background: transparent; } }
@keyframes search-target { 0%, 35% { box-shadow: 0 0 0 4px var(--color-cinnabar-soft), 0 0 0 1px var(--color-accent); } 100% { box-shadow: none; } }
.toast { position: fixed; z-index: 300; left: 50%; bottom: 1.75rem; max-width: min(32.5rem, 86vw); padding: 0.75rem 1.125rem; color: #fff; background: #262c2a; box-shadow: 0 0.75rem 1.875rem rgba(0,0,0,.2); opacity: 0; pointer-events: none; transform: translate(-50%, 1.125rem); transition: .25s; font-size: 0.75rem; }
.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* 显示设置抽屉：从导航栏打开，所有修改即时预览。 */
.settings-dialog { width: 100%; max-width: none; height: 100%; max-height: none; margin: 0; padding: 0; border: 0; background: transparent; overflow: clip; pointer-events: none; }
.settings-dialog[open] { display: flex; justify-content: flex-end; pointer-events: auto; }
.settings-dialog::backdrop { background: rgba(25, 28, 27, .58); }
.settings-panel { width: min(28rem, 100vw); height: 100%; min-width: 0; padding: var(--space-lg); display: grid; grid-template-rows: auto minmax(0, 1fr) auto; color: var(--color-ink); background: var(--color-paper-soft); border-left: var(--rule-hairline) solid var(--color-rule-strong); box-shadow: -1.25rem 0 3rem var(--color-shadow-soft); overflow: clip; contain: paint; }
.settings-dialog.is-closing .settings-panel { pointer-events: none; }
.settings-head { min-height: 4.5rem; padding-bottom: var(--space-md); display: flex; align-items: center; justify-content: space-between; border-bottom: var(--rule-hairline) solid var(--color-rule); }
.settings-head small { display: block; color: var(--color-accent); font-size: var(--text-xs); font-weight: 700; }
.settings-head h2 { margin: var(--space-3xs) 0 0; font: 600 var(--text-xl)/1.2 var(--font-display); }
.settings-close { width: 2.75rem; height: 2.75rem; padding: 0; display: grid; place-items: center; border: var(--rule-hairline) solid transparent; background: transparent; cursor: pointer; font-size: 1.6rem; line-height: 1; }
.settings-close:hover { color: var(--color-accent); border-color: var(--color-rule); background: var(--color-paper-deep); }
.settings-close:active { background: var(--color-paper-deep); }
.settings-close:focus-visible, .settings-footer button:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 2px; }
.settings-form { min-width: 0; padding: var(--space-md) var(--space-3xs) var(--space-lg); overflow-x: clip; overflow-y: auto; overscroll-behavior: contain; }
.settings-group { margin: 0; padding: 0; border: 0; }
.settings-group + .settings-group { margin-top: var(--space-2xl); padding-top: 0; border-top: 0; }
.settings-group legend { width: 100%; margin-bottom: var(--space-md); padding: 0; color: var(--color-ink-muted); font: 600 var(--text-lg)/1.35 var(--font-display); }
.setting-control + .setting-control,
.range-setting + .range-setting,
.system-motion-note + .range-setting,
.setting-check + .setting-check { margin-top: var(--space-lg); }
.sound-toggle-row + .music-track-tabs,
.music-track-tabs + .range-setting { margin-top: var(--space-lg); }
.setting-check + .range-setting { margin-top: var(--space-lg); }
.setting-label,
.range-setting b,
.setting-check span { display: block; color: var(--color-ink-muted); font: 600 var(--text-md)/1.4 var(--font-display); }
.setting-check span { display: inline-flex; align-items: center; }
.setting-check { display: flex; align-items: center; gap: var(--space-xs); color: var(--color-ink-muted); cursor: var(--cursor-pointer) !important; }
.setting-check input { width: 1.15rem; height: 1.15rem; margin: 0; accent-color: var(--color-accent); cursor: var(--cursor-pointer) !important; }
.sound-toggle-row { display: flex; align-items: center; justify-content: flex-start; gap: var(--space-2xs); }
.music-track-tabs { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); margin-top: var(--space-md); border: var(--rule-hairline) solid var(--color-rule-strong); }
.music-track-tabs label { min-width: 0; cursor: var(--cursor-pointer) !important; }
.music-track-tabs input { position: absolute; width: 1px; height: 1px; opacity: 0; }
.music-track-tabs span { min-height: 2.75rem; display: grid; place-items: center; padding-inline: var(--space-2xs); color: var(--color-ink-muted); border-right: var(--rule-hairline) solid var(--color-rule); cursor: var(--cursor-pointer) !important; font: inherit; font-size: var(--text-sm); white-space: nowrap; transition: color var(--dur-short) var(--ease-out), background-color var(--dur-short) var(--ease-out); }
.music-track-tabs label:last-child span { border-right: 0; }
.music-track-tabs input:checked + span { color: var(--color-accent-ink); background: var(--color-accent); }
.music-track-tabs input:focus-visible + span { outline: 2px solid var(--color-focus); outline-offset: -3px; }
.music-action-buttons { display: flex; align-items: center; gap: var(--space-3xs); }
.music-restart-button,
.music-carousel-button,
.music-next-button { width: 2.75rem; height: 2.75rem; display: grid; place-items: center; padding: 0; color: var(--color-ink-muted); border: 1px solid transparent; background: transparent; cursor: var(--cursor-pointer) !important; font-size: 1.35rem; line-height: 1; }
.music-restart-button:hover:not(:disabled),
.music-carousel-button:hover:not(:disabled),
.music-next-button:hover:not(:disabled) { color: var(--color-accent); }
.music-carousel-button[data-enabled="true"] { color: var(--color-accent); border-color: var(--color-rule); background: var(--color-paper-deep); }
.music-restart-button:active:not(:disabled),
.music-carousel-button:active:not(:disabled),
.music-next-button:active:not(:disabled) { color: var(--color-accent-dark); background: var(--color-paper-deep); }
.music-restart-button:focus-visible,
.music-carousel-button:focus-visible,
.music-next-button:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 2px; }
.music-restart-button:disabled,
.music-carousel-button:disabled,
.music-next-button:disabled { cursor: not-allowed; opacity: .4; }
.setting-label { margin-bottom: var(--space-xs); }
.segmented-control { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); border: var(--rule-hairline) solid var(--color-rule-strong); }
.segmented-control label { min-width: 0; cursor: var(--cursor-pointer) !important; }
.segmented-control input { position: absolute; width: 1px; height: 1px; opacity: 0; cursor: var(--cursor-pointer) !important; }
.segmented-control span { min-height: 2.75rem; display: grid; place-items: center; color: var(--color-ink-muted); border-right: var(--rule-hairline) solid var(--color-rule); cursor: var(--cursor-pointer) !important; font-size: var(--text-sm); white-space: nowrap; transition: color var(--dur-short) var(--ease-out), background-color var(--dur-short) var(--ease-out); }
.segmented-control label:last-child span { border-right: 0; }
.segmented-control input:checked + span { color: var(--color-accent-ink); background: var(--color-accent); }
.segmented-control input:focus-visible + span { outline: 2px solid var(--color-focus); outline-offset: -3px; }
.range-setting { display: block; }
.range-setting > span, .range-setting > small { display: flex; align-items: center; justify-content: space-between; }
.range-setting output { color: var(--color-accent); font: 700 var(--text-md)/1.4 var(--font-body); }
.range-setting > small { color: var(--color-ink-muted); font-size: var(--text-xs); }
.range-setting input[type="range"] { width: 100%; height: 2.75rem; margin: var(--space-2xs) 0 0; accent-color: var(--color-accent); cursor: pointer; }
.range-setting input[type="range"]:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 1px; }
.system-motion-note { margin: var(--space-md) 0 0; padding: var(--space-xs); color: var(--color-ink-muted); border: var(--rule-hairline) solid var(--color-rule); font-size: var(--text-xs); line-height: 1.6; }
.settings-footer { padding-top: var(--space-md); display: flex; align-items: center; justify-content: space-between; gap: var(--space-sm); border-top: var(--rule-hairline) solid var(--color-rule); }
.settings-footer button { min-height: 2.75rem; padding: 0 var(--space-md); border: var(--rule-hairline) solid var(--color-rule-strong); background: transparent; cursor: pointer; font-weight: 600; white-space: nowrap; }
.settings-footer button:hover { border-color: var(--color-accent); }
.settings-footer button:active { background: var(--color-paper-deep); }
#doneSettings { color: var(--color-accent-ink); border-color: var(--color-accent); background: var(--color-accent); }
#doneSettings:hover { background: var(--color-accent-dark); }

/* 阅读设置仅作用于正文和说明，不缩放导航、按钮与展示标题。 */
html :is(.hero-lead, .heading-note, .intro-copy, .story-details p, .relic-info p, .map-heading > p, #siteDescription, .map-knowledge p, .source-findings p, .source-index p, .course-recap-copy p, .course-scroll-footer p, .ai-intro > p:not(.eyebrow), .ai-intro li) { font-size: .9rem; line-height: 1.8; }

/* 动效强度主要控制空间位移；0% 时保留内容但取消移动。 */
html[data-motion="0"] { scroll-behavior: auto; }
html[data-motion="0"] [data-reveal] { opacity: 1 !important; transform: none !important; transition: none !important; }
html[data-motion="0"] .collection-grid .relic-card,
html[data-motion="0"] .story-grid .story-card,
html[data-motion="0"] .knowledge-functions article,
html[data-motion="0"] .source-findings article,
html[data-motion="0"] .source-index article { opacity: 1; transform: none; transition: border-color var(--dur-short) var(--ease-out), box-shadow var(--dur-short) var(--ease-out); }
html[data-motion="0"] .hero-relic-main { animation: none; }
html[data-motion="0"] .hero-relic { transform: none !important; }

/* ==================== 08. 开源课程板块 ==================== */
.course-section { padding: 7rem 0; background: var(--section-bg); }
.course-browser { margin-top: 3.25rem; display: grid; grid-template-columns: minmax(0, 1.7fr) minmax(18rem, .75fr); gap: var(--space-lg); align-items: start; }
.course-browser-main { min-width: 0; }
.course-lesson-panel { min-width: 0; position: sticky; top: 6.5rem; }
.course-lesson-panel { padding: var(--space-md); border: var(--rule-hairline) solid var(--color-rule); background: color-mix(in srgb, var(--color-paper-soft) 74%, transparent); }
.course-lesson-panel-head { padding-bottom: var(--space-md); border-bottom: 1px solid var(--color-rule); }
.course-lesson-panel-label { margin: 0 0 .55rem; color: var(--color-accent); font-size: var(--text-xs); font-weight: 700; letter-spacing: .08em; }
.course-lesson-panel-intro { max-width: 18rem; margin: 0; color: var(--color-ink-muted); font-size: var(--text-sm); line-height: 1.8; }
.course-recap-feature { margin-top: 3.25rem; color: var(--color-ink); border: var(--rule-hairline) solid var(--color-rule); background: var(--color-paper-soft); }
.course-browser .course-recap-feature { margin-top: 0; }
.course-recap-media { aspect-ratio: 16 / 9; overflow: hidden; background: #101513; }
.course-recap-media video { width: 100%; height: 100%; display: block; object-fit: contain; background: #101513; }
.course-recap-copy { padding: var(--space-lg); }
.course-recap-copy > span { color: var(--color-accent); font-size: var(--text-sm); font-weight: 700; }
.course-recap-copy h3 { margin: .55rem 0 .65rem; font: 400 clamp(1.65rem, 3vw, 2.35rem) var(--font-display); }
.course-recap-copy p { max-width: 54rem; margin: 0; color: var(--color-ink-muted); line-height: 1.8; }

.course-scroll { margin-top: var(--space-xl); overflow: hidden; border: var(--rule-hairline) solid var(--color-rule); background: var(--color-paper-soft); scroll-margin-top: 6.5rem; }
.course-scroll-bar { min-height: 5.5rem; padding: var(--space-md) var(--space-lg); display: flex; align-items: center; justify-content: space-between; gap: var(--space-lg); border-bottom: var(--rule-hairline) solid var(--color-rule); }
.course-scroll-bar > div:first-child { min-width: 0; }
.course-scroll-bar > div:first-child span { display: block; color: var(--color-accent); font-size: var(--text-xs); }
.course-scroll-bar > div:first-child strong { display: block; margin-top: .35rem; overflow: hidden; text-overflow: ellipsis; font: 400 clamp(1.1rem, 2vw, 1.45rem) var(--font-display); white-space: nowrap; }
.course-scroll-controls { flex: 0 0 auto; display: flex; align-items: center; gap: var(--space-xs); }
.course-scroll-controls button { width: 2.75rem; height: 2.75rem; display: grid; place-items: center; color: var(--color-ink); border: var(--rule-hairline) solid var(--color-rule); background: transparent; cursor: var(--cursor-pointer); }
.course-scroll-controls button:disabled { cursor: not-allowed; opacity: .35; }
.course-scroll-controls p { min-width: 8rem; margin: 0; text-align: center; }
.course-scroll-controls p span,
.course-scroll-controls p b { display: block; }
.course-scroll-controls p span { color: var(--color-ink-muted); font-size: var(--text-xs); }
.course-scroll-controls p b { margin-top: .2rem; font-size: var(--text-sm); }
.course-lesson-tabs { position: relative; display: grid; gap: var(--space-sm); padding: var(--space-md) 0; }
.course-lesson-tabs button { min-width: 0; min-height: 8rem; padding: var(--space-md); display: grid; grid-template-columns: 2.1rem minmax(0, 1fr) 1.2rem; grid-template-rows: auto auto; align-items: center; gap: var(--space-sm); color: var(--color-ink-muted); border: var(--rule-hairline) solid var(--color-rule); background: var(--color-paper-soft); cursor: var(--cursor-pointer); text-align: left; transform: none; transition: border-color var(--dur-short) var(--ease-out), background-color var(--dur-short) var(--ease-out), box-shadow var(--dur-short) var(--ease-out); }
.course-lesson-tabs button strong { color: inherit; font: 400 clamp(1rem, 1.5vw, 1.25rem) var(--font-display); line-height: 1.55; }
.course-lesson-tabs button small { grid-column: 2 / 4; color: inherit; white-space: nowrap; }
.course-lesson-tabs button::after { content: "→"; grid-column: 3; grid-row: 1; color: var(--color-ink-muted); font-size: 1.15rem; }
.course-lesson-tabs button:hover { border-color: var(--color-accent); }
.course-lesson-tabs button.active { color: var(--color-ink); border-color: var(--color-accent); background: var(--color-cinnabar-soft); box-shadow: inset .2rem 0 0 var(--color-accent); }
.course-lesson-tabs button.active::after { color: var(--color-accent); }
.course-lesson-tabs button.is-switching { animation: course-tab-switch 220ms var(--ease-out) both; }
@keyframes course-tab-switch {
  0% { opacity: .72; transform: translateY(2px); }
  100% { opacity: 1; transform: translateY(0); }
}
.course-lesson-panel-foot { padding-top: var(--space-md); display: flex; justify-content: space-between; gap: var(--space-sm); border-top: 1px solid var(--color-rule); color: var(--color-ink-muted); font-size: var(--text-xs); }
.course-lesson-panel-foot strong { color: var(--color-accent); font-size: var(--text-sm); }
.course-scroll-progress { position: relative; height: 14px; overflow: hidden; background: linear-gradient(to bottom, var(--color-rule) 0 3px, transparent 3px); cursor: grab; touch-action: none; outline: 0; user-select: none; }
.course-scroll-progress::after { content: ""; position: absolute; inset: 0 0 auto; height: 3px; background: var(--color-rule); pointer-events: none; }
.course-scroll-progress:hover::after,
.course-scroll-progress:focus-visible::after { background: color-mix(in oklch, var(--color-accent) 35%, var(--color-rule)); }
.course-scroll-progress:focus-visible { box-shadow: inset 0 0 0 1px var(--color-focus); }
.course-scroll-progress.is-dragging { cursor: grabbing; }
.course-scroll-progress i { width: 100%; height: 3px; display: block; position: relative; z-index: 1; background: var(--color-accent); transform: scaleX(0); transform-origin: left; transition: transform 100ms var(--ease-out); pointer-events: none; }
.course-scroll-progress.is-dragging i { transition: none; }
.course-slide-viewport {
  overflow-x: auto;
  overflow-y: hidden;
  cursor: grab;
  scrollbar-width: thin;
  scrollbar-color: var(--theme-scrollbar-thumb) var(--theme-scrollbar-track);
  overscroll-behavior-inline: contain;
  touch-action: pan-x pan-y;
  user-select: none;
  -webkit-user-select: none;
}
.course-slide-viewport::-webkit-scrollbar { height: 12px; }
.course-slide-viewport::-webkit-scrollbar-track { background: var(--theme-scrollbar-track); }
.course-slide-viewport::-webkit-scrollbar-thumb { border: 3px solid var(--theme-scrollbar-track); border-radius: 999px; background: var(--theme-scrollbar-thumb); }
.course-slide-viewport::-webkit-scrollbar-thumb:hover { background: var(--theme-scrollbar-thumb-hover); }
.course-slide-viewport.is-dragging { cursor: grabbing; }
.course-slide-track { width: max-content; height: auto; display: flex; padding: 0; background: #101513; }
.course-slide { position: relative; width: min(100vw, var(--course-slide-width, 50rem)); height: auto; aspect-ratio: 16 / 9; flex: 0 0 var(--course-slide-width, 50rem); margin: 0; background: #101513; }
.course-slide img { width: 100%; height: 100%; display: block; object-fit: contain; background: #101513; cursor: inherit; image-rendering: auto; pointer-events: none; -webkit-user-drag: none; user-drag: none; }
.course-scroll-footer { padding: var(--space-lg); display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: var(--space-xl); border-top: var(--rule-hairline) solid var(--color-rule); }
.course-scroll-footer > div:first-child > span { color: var(--color-accent); font-size: var(--text-sm); font-weight: 700; }
.course-scroll-footer p { max-width: 50rem; margin: .6rem 0 0; color: var(--color-ink-muted); line-height: 1.75; }
.course-scroll-actions { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: var(--space-xs); }
.course-scroll-actions .button { min-height: 2.75rem; white-space: nowrap; }
.course-scroll-hint { margin: 0; padding: 0 var(--space-lg) var(--space-md); color: var(--color-ink-muted); font-size: var(--text-xs); }

.course-scroll button:focus-visible,
.course-scroll a:focus-visible,
.course-recap-media video:focus-visible { outline: 2px solid var(--color-accent); outline-offset: 3px; }
.course-scroll-controls button:hover:not(:disabled) { color: var(--color-accent-ink); background: var(--color-accent); }
.course-scroll-controls button:active:not(:disabled) { color: var(--color-accent-dark); background: var(--color-paper-deep); }
.course-lesson-tabs button:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 2px; }
.course-scroll-controls button.is-pressing:not(:disabled) { transform: scale(.95); }
.course-lesson-tabs button:active:not(:disabled) { background: var(--color-cinnabar-soft); }

@media (prefers-reduced-motion: reduce) {
  .course-lesson-tabs button.is-switching { animation: course-tab-switch-reduced 160ms ease-out both; }
  @keyframes course-tab-switch-reduced {
    from { opacity: .76; }
    to { opacity: 1; }
  }
}

@media (max-width: 47.5rem) {
  .course-browser { grid-template-columns: 1fr; gap: var(--space-md); }
  .course-lesson-panel { position: static; order: -1; }
  .course-lesson-panel { padding: var(--space-sm); }
  .course-lesson-panel-intro { max-width: none; }
  .course-recap-feature { margin-top: var(--space-xl); }
  .course-recap-copy { padding: var(--space-md); }
  .course-scroll-bar { align-items: flex-start; padding: var(--space-md); }
  .course-scroll-bar > div:first-child strong { max-width: 12rem; }
  .course-scroll-controls { gap: .25rem; }
  .course-scroll-controls p { min-width: 5.25rem; }
  .course-lesson-tabs { display: flex; overflow-x: auto; scrollbar-width: thin; }
  .course-lesson-tabs button { flex: 0 0 11rem; min-height: 6.5rem; grid-template-columns: auto 1fr; }
  .course-lesson-tabs button small { grid-column: 2; }
  .course-lesson-tabs button::after { display: none; }
  .course-slide { min-height: 15rem; }
  .course-scroll-footer { grid-template-columns: 1fr; gap: var(--space-md); padding: var(--space-md); }
  .course-scroll-actions { justify-content: flex-start; }
  .course-scroll-hint { padding-inline: var(--space-md); }
}

/* ==================== 09. 封泥牌具展示板块 ==================== */
.creative-section { padding: 7rem 0; color: var(--ink); background: var(--section-bg); }

/* 封泥牌具：Canvas 使用全宽展台，不再使用装饰卡片。 */
.product-3d-section { padding-bottom: 4rem !important; overflow: clip; }
.product-3d-heading { padding-bottom: var(--space-xl); }
.product-3d-showcase { width: min(var(--layout-content-max), var(--layout-content-width)); min-width: 0; margin-inline: auto; color: var(--color-dark-ink); background: var(--color-dark-surface); border: var(--rule-hairline) solid var(--color-rule-strong); }
.product-3d-stage { width: min(100%, 100rem); min-height: var(--layout-product-3d-height); margin: 0 auto; display: grid; grid-template-columns: minmax(0, 1fr) minmax(18rem, var(--layout-product-3d-caption-width)); }
.product-3d-viewport { position: relative; min-width: 0; height: var(--layout-product-3d-height); overflow: clip; outline: 0; touch-action: none; cursor: grab; background-color: #183a34; background-image: radial-gradient(circle at 50% 45%, rgba(103,145,132,.12), transparent 42%), linear-gradient(135deg, #244941, #132f2b); background-size: 2.75rem 2.75rem; }
.product-3d-viewport:active { cursor: grabbing; }
.product-3d-viewport:focus-visible { outline: 2px solid var(--color-map-marker); outline-offset: -3px; }
.product-3d-viewport:fullscreen { width: 100vw; height: 100vh; background-color: #183a34; background-image: radial-gradient(circle at 50% 45%, rgba(103,145,132,.12), transparent 42%), linear-gradient(135deg, #244941, #132f2b); background-size: 2.75rem 2.75rem; }
#product3dCanvas { width: 100%; height: 100%; display: block; }
.product-3d-status { position: absolute; z-index: 2; left: var(--space-md); top: var(--space-md); margin: 0; color: var(--color-dark-muted); font-size: var(--text-xs); pointer-events: none; }
.product-3d-mode { position: absolute; z-index: 3; right: var(--space-md); top: var(--space-md); display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); border: var(--rule-hairline) solid color-mix(in oklch, var(--color-dark-ink) 24%, transparent); background: color-mix(in oklch, var(--color-dark-surface) 88%, transparent); }
.product-3d-mode button { min-width: 5.5rem; min-height: 2.75rem; padding: 0 var(--space-sm); color: var(--color-dark-muted); border: 0; border-right: var(--rule-hairline) solid color-mix(in oklch, var(--color-dark-ink) 18%, transparent); background: transparent; cursor: var(--cursor-pointer) !important; white-space: nowrap; }
.product-3d-mode button:last-child { border-right: 0; }
.product-3d-mode button.active { color: var(--color-accent-ink); background: var(--color-accent); }
.product-3d-mode button:focus-visible, .product-3d-controls button:focus-visible { outline: 2px solid var(--color-map-marker); outline-offset: -3px; }
.product-3d-controls { position: absolute; z-index: 3; left: 50%; bottom: var(--space-md); width: min(46rem, calc(100% - 2rem)); min-height: 3rem; display: grid; grid-template-columns: 3rem minmax(6.5rem, 1fr) 3rem repeat(3, minmax(5.25rem, auto)); transform: translateX(-50%); border: var(--rule-hairline) solid color-mix(in oklch, var(--color-dark-ink) 20%, transparent); background: color-mix(in oklch, var(--color-dark-surface) 90%, transparent); }
.product-3d-controls button { min-width: 0; min-height: 3rem; padding: 0 var(--space-xs); color: var(--color-dark-ink); border: 0; border-right: var(--rule-hairline) solid color-mix(in oklch, var(--color-dark-ink) 16%, transparent); background: transparent; cursor: var(--cursor-pointer) !important; font-size: var(--text-xs); white-space: nowrap; }
.product-3d-controls button:last-child { border-right: 0; }
.product-3d-controls button:hover, .product-3d-controls button[aria-pressed="true"] { color: var(--color-accent-ink); background: var(--color-accent); }
.product-3d-caption { min-width: 0; height: var(--layout-product-3d-height); padding: var(--space-xl) var(--space-lg); display: flex; flex-direction: column; color: var(--color-ink); background: var(--color-paper-soft); border-left: var(--rule-hairline) solid var(--color-rule-strong); }
.product-3d-caption-head { padding-bottom: var(--space-md); display: flex; align-items: center; justify-content: space-between; gap: var(--space-sm); color: var(--color-accent); border-bottom: var(--rule-hairline) solid var(--color-rule); font-size: var(--text-xs); }
.product-3d-caption h3 { margin: var(--space-xl) 0 var(--space-sm); font: 600 var(--text-2xl)/1.25 var(--font-display); }
.product-3d-caption > p { margin: 0; color: var(--color-ink-muted); line-height: 1.9; }
.product-3d-caption dl { margin: auto 0 0; }
.product-3d-caption dl div { padding: var(--space-sm) 0; border-top: var(--rule-hairline) solid var(--color-rule); }
.product-3d-caption dt { color: var(--color-ink-muted); font-size: var(--text-xs); }
.product-3d-caption dd { margin: var(--space-2xs) 0 0; overflow-wrap: anywhere; font-size: var(--text-xs); line-height: 1.65; }

@media (max-width: 62rem) {
  .product-3d-stage { grid-template-columns: minmax(0, 1fr); }
  .product-3d-viewport { height: var(--layout-product-3d-height-mobile); }
  .product-3d-caption { width: 100%; height: auto; min-height: 23rem; border-left: 0; border-top: var(--rule-hairline) solid var(--color-rule-strong); }
}

@media (max-width: 47.5rem) {
  .product-3d-heading { padding-bottom: var(--space-lg); }
  .product-3d-status { left: var(--space-sm); top: var(--space-sm); max-width: 11rem; }
  .product-3d-mode { right: var(--space-sm); top: var(--space-sm); }
  .product-3d-mode button { min-width: 4.75rem; padding-inline: var(--space-xs); }
  .product-3d-controls { bottom: var(--space-sm); width: calc(100% - 1rem); grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .product-3d-controls button { min-height: 2.75rem; border-bottom: var(--rule-hairline) solid color-mix(in oklch, var(--color-dark-ink) 16%, transparent); }
  .product-3d-controls button:nth-child(3n) { border-right: 0; }
  .product-3d-controls button:nth-last-child(-n+3) { border-bottom: 0; }
  .product-3d-caption { min-height: 25rem; padding: var(--space-lg) var(--space-md); }
  .product-3d-caption h3 { margin-top: var(--space-lg); font-size: var(--text-xl); }
}

/* ==================== 10. AI 助手：介绍文字、聊天窗口、上传和快捷问题 ==================== */
.ai-section { padding: 7.5rem 0; display: grid; grid-template-columns: minmax(0, .85fr) minmax(24rem, 1.15fr); align-items: center; gap: clamp(3rem, 8vw, 8rem); background: var(--section-bg); }
.ai-intro h2 { margin: 0; font: 600 clamp(2.25rem, 4vw, 3.5rem)/1.45 var(--serif); }
.ai-intro > p:not(.eyebrow) { margin: 1.5rem 0; color: var(--muted); font-size: .85rem; line-height: 1.9; }
.ai-intro ul { padding: 0; list-style: none; color: #55514b; font-size: .78rem; }
.ai-intro li { padding: .75rem 0; border-bottom: 1px solid var(--line); }
.ai-intro li::before { content: "＋"; margin-right: .75rem; color: var(--red); }
.ai-console { min-height: 38rem; padding: 1.3rem; display: flex; flex-direction: column; background: var(--color-paper-soft); border: 1px solid var(--line); }
.ai-console-head { display: grid; grid-template-columns: 3.1rem 1fr 2.5rem; align-items: center; gap: .85rem; padding-bottom: 1rem; border-bottom: 1px solid var(--line); }
.mascot-mark { width: 3rem; aspect-ratio: 1; position: relative; overflow: hidden; border: 1px solid rgba(168, 51, 42, .35); border-radius: 50%; background: #f4dfb1; }
/* The source canvas includes the body and tail, so align the face instead of the full PNG. */
.mascot-mark img { position: absolute; width: 235%; max-width: none; left: 62%; top: 73%; transform: translate(-50%, -50%); }
.ai-console-head strong, .ai-console-head small { display: block; }
.ai-console-head strong { font: 600 1rem var(--serif); }
.ai-console-head small { margin-top: .25rem; color: var(--muted); font-size: .62rem; }
.ai-console-head small i { display: inline-block; width: .4rem; height: .4rem; margin-right: .35rem; border-radius: 50%; background: #4d8b61; }
.ai-console-head small.checking i { background: #b08a3e; }
.ai-console-head small.disconnected i { background: var(--red); }
.ai-console-head button { width: 2.3rem; height: 2.3rem; border: 0; background: transparent; cursor: pointer; font-size: 1.2rem; }
.chat-messages { min-height: 18rem; max-height: 22rem; padding: 1.25rem .25rem; flex: 1; overflow: auto; }
.chat-message {
  width: fit-content;
  max-width: 82%;
  margin-bottom: .75rem;
  padding: .8rem 1rem;
  border-radius: .75rem;
  font-size: .76rem;
  line-height: 1.7;
  background: #f2eee5;
}
.chat-message p { margin: 0 0 .65rem; }
.chat-message p:last-child { margin-bottom: 0; }
.chat-message h1, .chat-message h2, .chat-message h3 { margin: .15rem 0 .65rem; font-family: var(--serif); line-height: 1.45; }
.chat-message h1 { font-size: 1.15rem; }.chat-message h2 { font-size: 1.05rem; }.chat-message h3 { font-size: .95rem; }
.chat-message ul, .chat-message ol { margin: .35rem 0 .65rem; padding-left: 1.35rem; }
.chat-message li + li { margin-top: .25rem; }
.chat-message code { padding: .08rem .3rem; color: #733029; background: rgba(157,47,38,.08); font-family: Consolas, monospace; font-size: .72rem; }
.chat-message pre { max-width: 100%; margin: .5rem 0; padding: .7rem; overflow-x: auto; color: #eee9df; background: #2e3532; }
.chat-message pre code { padding: 0; color: inherit; background: transparent; white-space: pre-wrap; }
.chat-message.user {
  margin-left: auto;
  color: #fff;
  background: var(--green);
  animation-name: chat-message-send;
}
.chat-message.assistant { animation-name: chat-message-answer; }
.chat-message.pending {
  color: var(--muted);
  animation: chat-message-answer .32s var(--ease-out) both, chat-pending-breathe 1.35s ease-in-out .32s infinite;
}

@keyframes chat-message-send {
  from { opacity: 0; transform: translate3d(.8rem, .15rem, 0) scale(.98); }
  to { opacity: 1; transform: translate3d(0, 0, 0) scale(1); }
}

@keyframes chat-message-answer {
  from { opacity: 0; transform: translate3d(-.8rem, .15rem, 0) scale(.98); }
  to { opacity: 1; transform: translate3d(0, 0, 0) scale(1); }
}

@keyframes chat-pending-breathe {
  0%, 100% { opacity: .62; }
  50% { opacity: 1; }
}
.quick-prompts { display: flex; flex-wrap: wrap; gap: .5rem; margin-bottom: .75rem; }
.quick-prompts button { padding: .5rem .75rem; color: var(--green-dark); border: 1px solid rgba(41,62,56,.25); border-radius: 2rem; background: transparent; cursor: pointer; font-size: .65rem; }
.upload-preview { margin-bottom: .75rem; padding: .75rem; background: rgba(242, 238, 229, .72); border: 1px solid var(--line); }
.upload-summary { display: flex; align-items: center; justify-content: space-between; gap: 1rem; margin-bottom: .65rem; }
.upload-summary strong { font-size: .72rem; }
.upload-summary button { padding: 0; color: var(--red); border: 0; background: transparent; cursor: pointer; font-size: .68rem; }
.upload-thumbnails { display: flex; gap: .6rem; overflow-x: auto; padding-bottom: .2rem; }
.upload-item { position: relative; width: 4.5rem; min-width: 4.5rem; max-width: 4.5rem; flex: 0 0 4.5rem; }
.upload-item img { width: 4.5rem; height: 4.5rem; display: block; object-fit: cover; border: 1px solid rgba(36,35,33,.15); }
.upload-item button { position: absolute; z-index: 2; right: 0; top: 0; width: 1.3rem; height: 1.3rem; display: grid; place-items: center; padding: 0; color: #fff; border: 0; border-radius: 50%; background: var(--red); cursor: pointer; font-size: .8rem; line-height: 1; transform: translate(35%, -35%); }
.upload-item span { width: 100%; display: block; margin-top: .3rem; overflow: hidden; color: var(--muted); font-size: .58rem; text-overflow: ellipsis; white-space: nowrap; }
.chat-form { display: grid; grid-template-columns: 2.8rem 1fr 3rem; min-height: 3.25rem; background: var(--color-paper); border: 1px solid var(--line); }
.chat-form input[type="text"] { min-width: 0; border: 0; outline: 0; background: transparent; }
.upload-control { display: grid; place-items: center; cursor: pointer; font-size: 1.3rem; }.upload-control input { display: none; }
.chat-form button { color: #fff; border: 0; background: var(--red); cursor: pointer; font-size: 1.2rem; }
.chat-form button:disabled { cursor: wait; opacity: .55; }
.ai-disclaimer { margin: .65rem 0 0; color: var(--muted); text-align: center; font-size: .58rem; }
.map-source-image { position: absolute; z-index: 1; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.shandong-map.has-source-image::before, .shandong-map.has-source-image .map-watermark { display: none; }

/* ==================== 11. 第一组响应式规则：平板和手机基础布局 ==================== */
@media (max-width: 75rem) {
  .course-layout { grid-template-columns: minmax(0, 1.15fr) minmax(17rem, .85fr); }
  .ai-section { gap: 3.5rem; }
}

@media (max-width: 62rem) {
  .course-layout, .ai-section { grid-template-columns: 1fr; }
  .course-list { display: grid; grid-template-columns: repeat(3, 1fr); }
  .course-list button { grid-template-columns: 1.7rem 1fr; align-items: start; }
  .course-list button i { display: none; }
}

@media (max-width: 47.5rem) {
  .heading-note { max-width: none; }
  .compact-heading h2 { white-space: normal; }
  .course-section, .creative-section, .ai-section { padding: 4.7rem 0; }
  .course-layout { margin-top: 2.25rem; }
  .video-shell { min-height: 15rem; }
  .course-video { min-height: 15rem; }
  .course-list { grid-template-columns: 1fr; }
  .course-list button { min-height: 6rem; grid-template-columns: 2rem 1fr 1.2rem; }
  .course-list button i { display: block; }
  .ai-section { width: calc(100% - 2.25rem); gap: 2.5rem; }
  .ai-console { min-height: 35rem; padding: 1rem; }
  .chat-message { max-width: 92%; }
  .quick-prompts { flex-wrap: nowrap; overflow-x: auto; }
  .quick-prompts button { flex: 0 0 auto; }
  .knowledge, .stories { padding: 4.7rem 0; }
  .story-grid { grid-template-columns: 1fr; }
  .story-card { min-height: 0; padding: 1.5rem 1rem; grid-template-columns: 2.4rem 1fr; }
  .search-results button { align-items: flex-start; flex-direction: column; gap: 0.25rem; }
  .search-results button span { text-align: left; }
  .music-button[data-playing="true"] { border-color: transparent; background: transparent; }
}

@media (max-width: 25rem) {
  .site-header { padding-inline: .8rem; }
  .brand strong { font-size: .9rem; }
  .hero { padding-inline: 1rem; }
  .hero-stats { gap: .5rem; }
  .hero-stats div { min-width: 0; padding-left: .55rem; }
  .map-toolbar { overflow-x: auto; }
  .map-toolbar-spacer { display: none; }
  .map-mode-switch { margin-left: .25rem; padding-left: .65rem; border-left: 1px solid var(--line); }
  .filter-chip { flex: 0 0 auto; }
}

/* 中等宽度以下恢复折叠菜单；菜单按钮固定在导航栏水平中心。 */
@media (max-width: 82rem) {
  .site-header { grid-template-columns: minmax(0, 1fr) auto; }
  .menu-toggle {
    position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%);
    width: 2.75rem; height: 2.75rem; display: grid; place-content: center; gap: 0.25rem;
    border: 0; background: transparent;
  }
  .menu-toggle span { width: 1.3125rem; height: 1px; background: var(--ink); }
  .main-nav {
    position: absolute; top: var(--layout-nav-menu-top); left: 0; right: 0;
    height: auto; max-height: calc(100dvh - var(--layout-nav-menu-top)); padding: 1rem 5vw;
    display: none; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0;
    overflow-x: hidden; overflow-y: auto; overscroll-behavior: contain;
    background: var(--color-navigation-surface); border-bottom: 1px solid var(--line);
  }
  .main-nav.open { display: grid; }
  .main-nav a { min-width: 0; min-height: 2.8125rem; height: auto; padding: .5rem; text-align: center; white-space: normal; }
  .hero { grid-template-columns: 1fr 1fr; padding-left: 6vw; padding-right: 5vw; }
  .collection-grid { grid-template-columns: repeat(2, 1fr); }
  .relic-visual { height: 20.625rem; }
}

@media (max-width: 47.5rem) {
  main > section[id] { scroll-margin-top: calc(var(--layout-header-height-mobile) - 0.5rem); }
  .site-header { height: var(--layout-header-height-mobile); padding: 0 1.125rem; }
  .brand small, .search-button span:last-child { display: none; }
  .header-actions { gap: 0; }
  .header-clock { min-width: 4.25rem; padding-inline: .25rem; font-size: .68rem; }
  .search-button, .music-button, .settings-button { width: 2.75rem; min-width: 2.75rem; height: 2.75rem; justify-content: center; padding: 0; }
  .brand-seal { width: 2.1875rem; height: 2.1875rem; }
  .site-header { grid-template-columns: minmax(0, 1fr) auto; }
  .main-nav {
    position: absolute; top: var(--layout-nav-menu-top-mobile); left: 0; right: 0;
    height: auto; max-height: calc(100dvh - var(--layout-nav-menu-top-mobile)); padding: 1rem 5vw;
    display: none; grid-template-columns: 1fr 1fr; gap: 0;
    overflow-x: hidden; overflow-y: auto; overscroll-behavior: contain;
    background: var(--color-navigation-surface); border-bottom: 1px solid var(--line);
  }
  .main-nav.open { display: grid; }
  .main-nav a { min-width: 0; min-height: 2.8125rem; height: auto; padding: .5rem; text-align: center; white-space: normal; }
  .hero { min-height: auto; padding: 6.5625rem 1.375rem 4.5rem; display: flex; flex-direction: column; align-items: stretch; background: #ece8df; }
  .hero::after { inset: 48% 0 0; mask-image: linear-gradient(transparent, black 20%); }
  .hero-copy { padding: 0; }
  .hero h1 { font-size: clamp(3.625rem, 18vw, 4.875rem); }
  .hero-lead { margin: 1.375rem 0; font-size: 0.9375rem; }
  .hero-actions { align-items: flex-start; flex-direction: column; gap: 0.625rem; }
  .hero-stats { margin-top: 2rem; gap: 1rem; }
  .hero-stats div { min-width: 4.375rem; }
  .hero-object { height: 26.25rem; margin-top: 0.9375rem; }
  .scroll-cue { display: none; }
  .section-shell { width: calc(100% - 2.25rem); }
  .intro, .collection { padding: 4.6875rem 0; }
  .section-heading h2 { font-size: 2.1875rem; }
  .map-section { padding: 4.6875rem 0; }
  .map-heading { align-items: start; flex-direction: column; gap: 1.125rem; }
  .map-layout { height: auto; grid-template-columns: 1fr; }
  .shandong-map { height: var(--layout-map-height-mobile); }
  .site-panel { height: var(--layout-site-panel-height-mobile); padding: 1.875rem 1.5625rem; }
  .site-city { margin-top: 1.75rem; }
  .split-heading { align-items: start; flex-direction: column; }
  .collection-grid { grid-template-columns: 1fr; }
  .relic-visual { height: 22.5rem; }
  .site-footer { grid-template-columns: 1fr; }
  .footer-links { flex-wrap: wrap; gap: 1rem 1.5625rem; }
  .search-box { padding: 2.8125rem 1.5rem 1.875rem; }
  .search-box label { font-size: 1.5rem; }
}

/* 极窄屏隐藏非必要时钟，优先保留品牌、菜单、搜索和设置操作。 */
@media (max-width: 35rem) {
  .header-clock { display: none; }
  .site-header { grid-template-columns: minmax(0, 1fr) auto; }
}

@media (max-width: 30rem) {
  .settings-panel { width: 100%; padding: var(--space-md); border-left: 0; }
  .settings-head h2 { font-size: var(--text-lg); }
}