:root {
  --header-h: 64px;
  --bg: #0f1115;
  --panel: rgba(14, 18, 28, 0.68);
  --panel-strong: rgba(12, 16, 24, 0.86);
  --text: #eef2f7;
  --muted: #b8c3d1;
  --line: rgba(255,255,255,0.16);
  --china: #d8a45f;
  --world: #71c8ff;
  --accent: #c7a56d;
  --shadow: 0 18px 48px rgba(0, 0, 0, 0.32);
  --hero-overlay: linear-gradient(90deg, rgba(71,33,14,0.72) 0%, rgba(17,20,29,0.18) 45%, rgba(3,30,51,0.72) 100%);
  --card-bg: rgba(250, 248, 243, 0.92);
  --card-text: #1f232b;
  --card-muted: #4c5563;
  --card-border: rgba(255,255,255,0.14);
  --tag-bg: rgba(255,255,255,0.08);
  --glow: rgba(199,165,109,0.34);
  --section-mask: linear-gradient(180deg, rgba(4,8,13,0.18), rgba(4,8,13,0.72));
}

* { box-sizing: border-box; }
html {
  scroll-behavior: smooth;
  scroll-snap-type: y mandatory;
  scroll-padding-top: var(--header-h);
}
body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans CJK SC", "Source Han Sans SC", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  transition: background 0.45s ease, color 0.45s ease;
  overflow-x: hidden;
}
body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(circle at 15% 10%, rgba(255,255,255,0.06), transparent 26%),
    radial-gradient(circle at 80% 18%, rgba(255,255,255,0.04), transparent 22%),
    linear-gradient(180deg, rgba(255,255,255,0.02), transparent 22%);
  mix-blend-mode: screen;
  opacity: 0.55;
  z-index: 0;
}

body.theme-ancient {
  --bg: #1c130f;
  --panel: rgba(37, 24, 17, 0.72);
  --panel-strong: rgba(32, 20, 14, 0.9);
  --muted: #dcc9b4;
  --accent: #d0ab73;
  --glow: rgba(201, 145, 72, 0.35);
  --hero-overlay: linear-gradient(90deg, rgba(82,41,19,0.74) 0%, rgba(43,28,18,0.22) 46%, rgba(21,43,60,0.72) 100%);
  --section-mask: linear-gradient(180deg, rgba(22,14,10,0.18), rgba(22,14,10,0.8));
}
body.theme-industrial {
  --bg: #1a1714;
  --panel: rgba(32, 24, 19, 0.72);
  --panel-strong: rgba(26, 20, 16, 0.9);
  --muted: #d7c9ba;
  --accent: #d18c4f;
  --glow: rgba(225, 121, 36, 0.28);
  --section-mask: linear-gradient(180deg, rgba(17,13,11,0.14), rgba(17,13,11,0.84));
}
body.theme-twentieth {
  --bg: #17191d;
  --panel: rgba(21, 25, 31, 0.74);
  --panel-strong: rgba(15, 18, 24, 0.92);
  --muted: #c4ccd8;
  --accent: #df8e4d;
  --glow: rgba(255, 122, 43, 0.25);
  --section-mask: linear-gradient(180deg, rgba(8,10,14,0.18), rgba(8,10,14,0.82));
}
body.theme-contemporary {
  --bg: #09131f;
  --panel: rgba(10, 22, 36, 0.72);
  --panel-strong: rgba(9, 18, 30, 0.9);
  --muted: #bfd7ea;
  --accent: #67cfff;
  --glow: rgba(60, 199, 255, 0.26);
  --section-mask: linear-gradient(180deg, rgba(4,10,16,0.16), rgba(4,10,16,0.8));
}
body.theme-future {
  --bg: #070b17;
  --panel: rgba(14, 15, 34, 0.72);
  --panel-strong: rgba(11, 11, 28, 0.92);
  --muted: #ced7ff;
  --accent: #8fa8ff;
  --glow: rgba(133, 154, 255, 0.25);
  --section-mask: linear-gradient(180deg, rgba(4,6,12,0.12), rgba(4,6,12,0.82));
}

.font-title {
  font-family: "STSong", "Songti SC", "SimSun", "Noto Serif CJK SC", "Source Han Serif SC", serif;
  letter-spacing: 0;
}

.hero-title-wrap {
  width: min(1040px, 100%);
  margin: 0 auto 20px;
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: 18px;
}
.hero-title-main {
  margin: 0;
  width: 100%;
  text-align: center;
  color: #fdfbf7;
  font-family: "STSong", "Songti SC", "SimSun", "Noto Serif CJK SC", "Source Han Serif SC", serif;
  font-size: 5.2rem;
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: 0;
  text-shadow:
    0 3px 10px rgba(0,0,0,0.28),
    0 12px 30px rgba(0,0,0,0.3);
  white-space: nowrap;
}
.hero-title-subtitle {
  margin: 0;
  width: 100%;
  text-align: right;
  color: #ecdcc0;
  font-family: "KaiTi", "STKaiti", "Kaiti SC", "FangSong", serif;
  font-size: 2.2rem;
  line-height: 1.3;
  letter-spacing: 0;
  text-shadow: 0 2px 10px rgba(0,0,0,0.28);
  padding-right: 12px;
}
.hero-supporting-text {
  margin: 16px auto 0;
  max-width: 820px;
  color: #e5d9c5;
  font-size: 1.08rem;
  line-height: 1.8;
  letter-spacing: 0;
  text-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.topbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  background: linear-gradient(180deg, rgba(8, 12, 18, 0.88), rgba(8, 12, 18, 0.54));
  border-bottom: 1px solid rgba(255,255,255,0.08);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  z-index: 100;
}
.topbar-left {
  display: flex;
  align-items: center;
  gap: 14px;
  min-width: 0;
}
.logo-box {
  width: 34px;
  height: 34px;
  border: 1px solid rgba(255,255,255,0.18);
  transform: rotate(45deg);
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  box-shadow: 0 0 22px var(--glow);
}
.logo-box span {
  transform: rotate(-45deg);
  font-family: "STSong", "Songti SC", "SimSun", "Noto Serif CJK SC", "Source Han Serif SC", serif;
  font-weight: 700;
  font-size: 18px;
  color: var(--accent);
}
.top-title-wrap {
  min-width: 0;
}
.top-title {
  font-size: 17px;
  font-weight: 700;
  line-height: 1.2;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.top-subtitle {
  font-size: 12px;
  color: var(--muted);
  margin-top: 2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.topbar-right {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font-size: 12px;
  text-align: right;
  flex: 0 0 auto;
}
.keycap {
  min-width: 28px;
  height: 28px;
  padding: 0 8px;
  border-radius: 8px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(255,255,255,0.14);
  background: rgba(255,255,255,0.05);
  color: #f2f5fa;
  font-size: 13px;
  font-weight: 700;
}

.progress-rail {
  position: fixed;
  top: 50%;
  transform: translateY(-50%);
  z-index: 70;
  width: 146px;
  padding: 14px 12px;
  border-radius: 18px;
  background: rgba(8, 12, 18, 0.42);
  border: 1px solid rgba(255,255,255,0.08);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: var(--shadow);
  pointer-events: none;
  user-select: none;
}
.progress-rail-left {
  left: 18px;
  right: auto;
}
.progress-rail-right {
  right: 18px;
  left: auto;
}
.progress-rail-left .progress-title {
  color: #f0dcc0;
}
.progress-rail-right .progress-title {
  color: #d4eefc;
}
.progress-title {
  font-size: 11px;
  color: var(--muted);
  letter-spacing: 0;
  text-transform: uppercase;
  margin-bottom: 10px;
}

.progress-rail::before {
  content: '';
  position: absolute;
  left: 16px;
  top: 42px;
  bottom: 18px;
  width: 2px;
  border-radius: 999px;
  background: linear-gradient(180deg, rgba(255,255,255,0.06), rgba(255,255,255,0.24), rgba(255,255,255,0.06));
  z-index: 0;
}

.progress-item {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 10px 0;
  opacity: 0.54;
  transition: opacity 0.35s ease, transform 0.35s ease;
}
.progress-item.active {
  opacity: 1;
  transform: translateX(-4px);
}
.progress-item.past {
  opacity: 0.76;
}
.progress-item.upcoming {
  opacity: 0.44;
}

.progress-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255,255,255,0.18);
  border: 1px solid rgba(255,255,255,0.16);
  box-shadow: 0 0 0 0 rgba(255,255,255,0.18);
  transition: background 0.35s ease, box-shadow 0.35s ease, transform 0.35s ease, filter 0.35s ease;
  flex: 0 0 auto;
}
.progress-item.active .progress-dot {
  background: var(--accent);
  box-shadow: 0 0 0 7px var(--glow);
  animation: progressPulse 1.7s ease-in-out infinite;
}
.progress-rail-left .progress-item.active .progress-dot {
  background: var(--china);
  box-shadow: 0 0 0 7px rgba(216,164,95,0.22);
}
.progress-rail-right .progress-item.active .progress-dot {
  background: var(--world);
  box-shadow: 0 0 0 7px rgba(113,200,255,0.22);
}
.progress-rail-left .progress-item.past .progress-dot {
  background: rgba(216,164,95,0.55);
  box-shadow: 0 0 0 4px rgba(216,164,95,0.08);
}
.progress-rail-right .progress-item.past .progress-dot {
  background: rgba(113,200,255,0.58);
  box-shadow: 0 0 0 4px rgba(113,200,255,0.08);
}

.progress-text {
  min-width: 0;
}
.progress-text strong {
  display: block;
  font-size: 13px;
  color: #f2f6fb;
  font-weight: 700;
  line-height: 1.2;
  transition: color 0.35s ease, text-shadow 0.35s ease;
}
.progress-text span {
  display: block;
  font-size: 11px;
  color: var(--muted);
  margin-top: 2px;
  line-height: 1.3;
  transition: color 0.35s ease;
}
.progress-item.active .progress-text strong {
  color: #ffffff;
  text-shadow: 0 0 12px rgba(255,255,255,0.14);
}
.progress-item.active .progress-text span {
  color: rgba(255,255,255,0.92);
}

@keyframes progressPulse {
  0%, 100% {
    transform: scale(1);
    filter: brightness(1);
  }
  50% {
    transform: scale(1.18);
    filter: brightness(1.18);
  }
}

main { position: relative; z-index: 1; }

.hero {
  min-height: 100vh;
  scroll-snap-align: start;
  position: relative;
  display: flex;
  align-items: center;
  padding: calc(var(--header-h) + 30px) 6vw 48px;
  background:
    var(--hero-overlay),
    url('../images/0_header_bg.webp') center/cover no-repeat;
  overflow: hidden;
}
.hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(4,8,12,0.1), rgba(4,8,12,0.58));
  pointer-events: none;
}
.hero-inner {
  position: relative;
  z-index: 2;
  width: min(1220px, calc(100vw - 360px));
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 24px;
  align-items: end;
}
.hero-copy {
  max-width: 760px;
}
.hero-kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 14px;
  border-radius: 999px;
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.12);
  color: #f4dcc3;
  font-size: 13px;
  margin-bottom: 14px;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.hero-kicker::before {
  content: '◉';
  color: var(--accent);
  font-size: 10px;
}
.hero h1 {
  margin: 0;
  font-size: 4.75rem;
  line-height: 1.08;
  text-shadow: 0 6px 20px rgba(0,0,0,0.36);
}
.hero p {
  margin: 14px 0 0;
  font-size: 1.08rem;
  line-height: 1.82;
  color: #edf0f5;
  max-width: 720px;
}
.hero-side {
  justify-self: end;
  width: min(440px, 100%);
  padding: 16px;
  border-radius: 24px;
  background: rgba(10, 14, 22, 0.44);
  border: 1px solid rgba(255,255,255,0.12);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: var(--shadow);
}
.hero-side-title {
  margin: 0 0 12px;
  font-size: 1.44rem;
  line-height: 1.2;
  color: #fff0db;
  text-shadow: 0 4px 16px rgba(0,0,0,0.28);
}
.legend-grid {
  display: grid;
  gap: 10px;
}
.legend-card {
  padding: 14px 16px;
  border-radius: 18px;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.08);
}
.legend-card strong {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  margin-bottom: 6px;
}
.legend-card strong::before {
  content: '';
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex: 0 0 auto;
  background: var(--accent);
  box-shadow: 0 0 14px var(--glow);
}
.legend-card.china strong::before { background: var(--china); box-shadow: 0 0 14px rgba(216,164,95,0.55); }
.legend-card.world strong::before { background: var(--world); box-shadow: 0 0 14px rgba(113,200,255,0.55); }
.legend-card p {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: #e7edf5;
}

.era-panel {
  position: relative;
  min-height: 100vh;
  padding: calc(var(--header-h) + 36px) 5vw 48px;
  scroll-snap-align: start;
  display: flex;
  align-items: center;
  overflow: hidden;
}
.era-panel::before {
  content: '';
  position: absolute;
  inset: 0;
  background-position: center;
  background-size: cover;
  background-repeat: no-repeat;
  transform: scale(1.03);
  transition: transform 1.2s ease;
}
.era-panel[data-era="ancient"]::before {
  background-image: var(--section-mask), url('../images/bg_stage1.webp');
}
.era-panel[data-era="medieval"]::before {
  background-image: var(--section-mask), url('../images/bg_stage2.webp');
}
.era-panel[data-era="industrial"]::before {
  background-image: var(--section-mask), url('../images/bg_stage3.webp');
}
.era-panel[data-era="twentieth"]::before {
  background-image: var(--section-mask), url('../images/bg_stage4.webp');
}
.era-panel[data-era="contemporary"]::before {
  background-image: var(--section-mask), url('../images/bg_stage5.webp');
}
.era-panel[data-era="outlook"]::before {
  background-image: var(--section-mask), url('../images/bg_stage6.webp');
}
.era-panel.in-view::before {
  transform: scale(1);
}
.era-panel::after {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 16% 14%, rgba(255,255,255,0.08), transparent 22%),
    linear-gradient(90deg, rgba(8,10,14,0.08), rgba(8,10,14,0.18), rgba(8,10,14,0.08));
  pointer-events: none;
}

.era-inner {
  position: relative;
  z-index: 2;
  width: min(1340px, calc(100vw - 360px));
  margin: 0 auto;
}
.era-head {
  display: grid;
  grid-template-columns: 170px 1fr;
  gap: 24px;
  align-items: end;
  margin-bottom: 26px;
}
.era-year {
  font-size: 2.9rem;
  font-weight: 900;
  line-height: 1;
  color: var(--accent);
  font-family: "STSong", "Songti SC", "SimSun", "Noto Serif CJK SC", "Source Han Serif SC", serif;
  text-shadow: 0 0 22px var(--glow);
}
.era-heading h2 {
  margin: 0;
  font-size: 2.45rem;
  line-height: 1.15;
}
.era-heading p {
  margin: 10px 0 0;
  max-width: 900px;
  line-height: 1.9;
  color: #eef3fa;
  font-size: 1rem;
}
.era-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 14px;
}
.tag {
  padding: 8px 12px;
  border-radius: 999px;
  background: var(--tag-bg);
  border: 1px solid rgba(255,255,255,0.10);
  font-size: 12px;
  color: #f3f7fb;
  letter-spacing: 0;
  backdrop-filter: blur(6px);
}

.timeline-shell {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 88px minmax(0, 1fr);
  gap: 16px;
  align-items: stretch;
}
.timeline-axis {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100%;
}
.timeline-axis::before {
  content: '';
  position: absolute;
  top: 20px;
  bottom: 20px;
  width: 2px;
  background: linear-gradient(180deg, rgba(255,255,255,0.14), rgba(255,255,255,0.5), rgba(255,255,255,0.14));
  box-shadow: 0 0 18px rgba(255,255,255,0.08);
}
.axis-core {
  position: sticky;
  top: calc(var(--header-h) + 110px);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  z-index: 2;
}
.axis-core .axis-node {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: radial-gradient(circle, #fff 0%, var(--accent) 48%, rgba(255,255,255,0.2) 100%);
  box-shadow: 0 0 0 10px var(--glow), 0 0 24px rgba(255,255,255,0.22);
}
.axis-core .axis-text {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-size: 12px;
  letter-spacing: 0;
  color: rgba(255,255,255,0.85);
  padding: 12px 0;
  text-shadow: 0 2px 10px rgba(0,0,0,0.25);
}

.track-card {
  position: relative;
  background: linear-gradient(180deg, rgba(8,12,18,0.45), rgba(8,12,18,0.64));
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: 28px;
  overflow: hidden;
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  min-height: 100%;
}
.track-card::before {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 28px;
}
.track-banner {
  position: relative;
  height: 250px;
  overflow: hidden;
}
.track-banner img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transform: scale(1.02);
  transition: transform 0.8s ease, filter 0.8s ease;
  filter: saturate(0.92) contrast(1.02) brightness(0.86);
}
.track-card:hover .track-banner img {
  transform: scale(1.07);
  filter: saturate(1.02) contrast(1.04) brightness(0.96);
}
.track-banner::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(8,12,18,0.08), rgba(8,12,18,0.68));
}
.track-mark {
  position: absolute;
  left: 20px;
  bottom: 16px;
  z-index: 2;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 9px 14px;
  border-radius: 999px;
  background: rgba(5,10,16,0.46);
  border: 1px solid rgba(255,255,255,0.12);
  font-weight: 700;
  letter-spacing: 0;
  backdrop-filter: blur(6px);
}
.track-mark::before {
  content: '';
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex: 0 0 auto;
}
.track-card.china .track-mark::before { background: var(--china); box-shadow: 0 0 14px rgba(216,164,95,0.5); }
.track-card.world .track-mark::before { background: var(--world); box-shadow: 0 0 14px rgba(113,200,255,0.55); }

.track-content {
  display: grid;
  gap: 16px;
  padding: 22px 22px 24px;
}
.track-summary {
  display: grid;
  gap: 12px;
  padding: 18px 18px 16px;
  border-radius: 22px;
  background: var(--card-bg);
  color: var(--card-text);
}
.track-summary h3 {
  margin: 0;
  font-size: 1.18rem;
  line-height: 1.4;
}
.track-summary p {
  margin: 0;
  line-height: 1.85;
  font-size: 0.95rem;
  color: var(--card-muted);
}
.track-summary .line-title {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  letter-spacing: 0;
  color: #7b5e3b;
  font-weight: 700;
  text-transform: uppercase;
}
.track-card.world .track-summary .line-title { color: #2e6e99; }
.track-summary .line-title::before {
  content: '';
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex: 0 0 auto;
}
.track-card.china .track-summary .line-title::before { background: var(--china); }
.track-card.world .track-summary .line-title::before { background: var(--world); }

.event-list {
  display: grid;
  gap: 12px;
}
.event-item {
  position: relative;
  padding: 15px 16px 15px 18px;
  border-radius: 18px;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.08);
}
.event-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 14px;
  bottom: 14px;
  width: 3px;
  border-radius: 2px;
  background: linear-gradient(180deg, transparent, rgba(255,255,255,0.9), transparent);
}
.track-card.china .event-item::before { background: linear-gradient(180deg, transparent, var(--china), transparent); }
.track-card.world .event-item::before { background: linear-gradient(180deg, transparent, var(--world), transparent); }
.event-time {
  display: inline-block;
  margin-bottom: 6px;
  font-size: 12px;
  color: #f2efe9;
  opacity: 0.9;
  letter-spacing: 0;
}
.event-title {
  font-size: 16px;
  font-weight: 700;
  line-height: 1.45;
  margin-bottom: 6px;
}
.event-desc {
  font-size: 14px;
  color: #dce6f1;
  line-height: 1.8;
}

.era-note {
  margin-top: 22px;
  padding: 16px 18px;
  border-radius: 22px;
  background: rgba(7,10,16,0.46);
  border: 1px solid rgba(255,255,255,0.10);
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.04);
}
.era-note strong {
  display: block;
  margin-bottom: 8px;
  font-size: 14px;
  color: #fff6e7;
  letter-spacing: 0;
}
.era-note p {
  margin: 0;
  color: #d9e5ef;
  line-height: 1.9;
  font-size: 14px;
}

.footer-panel {
  position: relative;
  min-height: 78vh;
  padding: calc(var(--header-h) + 36px) 5vw 56px;
  scroll-snap-align: start;
  display: flex;
  align-items: center;
  overflow: hidden;
  background:
    linear-gradient(180deg, rgba(7,9,15,0.36), rgba(7,9,15,0.84)),
    url('../images/bg_footer.webp') center/cover no-repeat;
}
.footer-panel::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at center, rgba(146,173,255,0.10), transparent 34%);
  pointer-events: none;
}
.footer-inner {
  position: relative;
  z-index: 2;
  width: min(1200px, calc(100vw - 360px));
  margin: 0 auto;
  display: grid;
  grid-template-columns: 0.95fr 1.05fr;
  gap: 24px;
  align-items: center;
}
.footer-image {
  border-radius: 28px;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.12);
  box-shadow: var(--shadow);
  aspect-ratio: 16 / 9;
  min-height: 0;
  background: #081019;
}
.footer-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.footer-copy {
  padding: 20px 0;
}
.footer-copy h2 {
  margin: 0 0 14px;
  font-size: 2.8rem;
  line-height: 1.15;
}
.footer-copy p {
  margin: 0 0 16px;
  line-height: 1.95;
  color: #e7eff8;
  font-size: 1rem;
}
.footer-list {
  display: grid;
  gap: 12px;
  margin-top: 22px;
}
.footer-item {
  padding: 14px 16px;
  border-radius: 18px;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.08);
  line-height: 1.8;
  color: #dce6f4;
  font-size: 14px;
}

.stage-counter {
  display: inline-flex;
  align-items: baseline;
  gap: 4px;
  padding: 6px 10px;
  border-radius: 12px;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.12);
  color: #f7f9fc;
  font-weight: 800;
  min-width: 62px;
  justify-content: center;
  letter-spacing: 0;
}
.stage-counter span {
  font-size: 18px;
  line-height: 1;
  color: var(--accent);
  text-shadow: 0 0 16px var(--glow);
}
.stage-counter small {
  font-size: 11px;
  color: var(--muted);
  font-weight: 700;
}

.hero-copy p b {
  color: #fff0db;
  font-weight: 700;
}

.focus-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 20px;
  max-width: 880px;
}
.focus-card {
  padding: 16px 16px 14px;
  border-radius: 18px;
  background: rgba(8, 12, 18, 0.34);
  border: 1px solid rgba(255,255,255,0.12);
  box-shadow: 0 10px 24px rgba(0,0,0,0.18);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}
.focus-card strong {
  display: block;
  margin-bottom: 8px;
  font-size: 14px;
  color: var(--accent);
  letter-spacing: 0;
}
.focus-card span {
  display: block;
  font-size: 14px;
  line-height: 1.7;
  color: #eef3f8;
}
.speaker-tip {
  margin-top: 18px;
  padding: 14px 16px;
  border-radius: 18px;
  max-width: 860px;
  background: rgba(255,255,255,0.07);
  border: 1px solid rgba(255,255,255,0.12);
  color: #f0f4f8;
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.04);
}

.era-head {
  grid-template-columns: 140px 1fr;
  gap: 22px;
  margin-bottom: 22px;
}
.era-heading p {
  max-width: 860px;
  font-size: 0.98rem;
  line-height: 1.85;
}
.era-meta { margin-top: 12px; }

.timeline-shell { gap: 18px; }

.track-card {
  opacity: 0.78;
  transform: translateY(22px);
  transition: transform 0.6s ease, opacity 0.6s ease, box-shadow 0.4s ease;
}
.era-panel.in-view .track-card {
  opacity: 1;
  transform: translateY(0);
}
.era-panel.in-view .track-card:nth-child(1) { transition-delay: 0.04s; }
.era-panel.in-view .track-card:nth-child(3) { transition-delay: 0.14s; }

.track-banner { height: 215px; }
.track-content {
  gap: 12px;
  padding: 18px 18px 20px;
}
.track-summary {
  padding: 16px 16px 14px;
  border-radius: 20px;
}
.track-summary h3 {
  font-size: 1.08rem;
  line-height: 1.5;
}
.track-summary p {
  font-size: 0.92rem;
  line-height: 1.75;
}
.event-list { gap: 10px; }
.event-item {
  padding: 13px 14px 13px 16px;
  border-radius: 16px;
}
.event-time {
  margin-bottom: 4px;
  font-size: 11px;
}
.event-title {
  font-size: 15px;
  margin-bottom: 4px;
}
.event-desc {
  font-size: 13px;
  line-height: 1.72;
}

.era-note {
  margin-top: 18px;
  padding: 14px 16px;
  border-radius: 18px;
}
.era-note strong {
  margin-bottom: 6px;
  font-size: 13px;
}
.era-note p {
  font-size: 13px;
  line-height: 1.78;
}

.mobile-indicator {
  display: none;
}

/* =========================================
   移动端深度适配优化
   ========================================= */

@media (max-width: 1200px) {
  .progress-rail { width: 140px; }
  .era-inner, .hero-inner, .footer-inner { width: 100%; }
}

@media (max-width: 980px) {
  :root { --header-h: 60px; }

  html { scroll-snap-type: none; }

  .topbar { padding: 0 16px; }
  .top-subtitle, .topbar-right .hint-text, .progress-rail { display: none; }
  .stage-counter { min-width: 50px; padding: 4px 8px; }
  .stage-counter span { font-size: 16px; }

  .hero, .era-panel, .footer-panel {
    min-height: auto;
    height: auto;
    padding: calc(var(--header-h) + 24px) 20px 40px;
    display: block;
  }

  .hero-inner, .footer-inner, .focus-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .era-head {
    grid-template-columns: 1fr;
    gap: 12px;
    margin-bottom: 24px;
  }

  .era-year {
    font-size: 2.8rem;
    text-align: left;
    text-shadow: 0 0 16px var(--glow);
  }

  .timeline-shell {
    display: flex;
    flex-direction: column;
    gap: 16px;
  }

  .timeline-axis {
    order: 0;
    min-height: auto;
    padding: 10px 0;
    display: flex;
    flex-direction: row;
    align-items: center;
  }

  .timeline-axis::before,
  .timeline-axis::after {
    content: '';
    flex: 1;
    height: 1px;
    background: linear-gradient(90deg, rgba(255,255,255,0.05), rgba(255,255,255,0.3), rgba(255,255,255,0.05));
    box-shadow: none;
    position: static;
    width: auto;
  }
  .timeline-axis::after { display: block; }

  .axis-core {
    flex: 0 0 auto;
    position: relative;
    top: auto;
    flex-direction: row;
    padding: 0 14px;
  }

  .axis-core .axis-text {
    writing-mode: horizontal-tb;
    letter-spacing: 0;
    padding: 0 0 0 8px;
    font-size: 13px;
  }

  .footer-inner { display: flex; flex-direction: column; }
  .footer-image { width: 100%; min-height: 0; flex: none; }
}

@media (max-width: 680px) {
  .hero h1 { font-size: 2.2rem; white-space: normal; line-height: 1.25; }
  .hero-title-subtitle { font-size: 1.3rem; text-align: left; padding: 0; }
  .hero p, .era-heading p, .footer-copy p, .focus-card span, .speaker-tip { font-size: 0.95rem; line-height: 1.7; }

  .era-heading h2 { font-size: 1.5rem; }

  .track-banner { height: 180px; }
  .track-content { padding: 16px; gap: 12px; }
  .track-summary { padding: 14px; border-radius: 16px; }
  .event-item { padding: 12px 14px; border-radius: 14px; }
  .event-title { font-size: 15px; }
  .event-desc { font-size: 13.5px; }

  .track-card, .hero-side, .footer-image { border-radius: 20px; }
  .top-title { font-size: 14px; }
  .keycap { min-width: 24px; height: 24px; font-size: 12px; }
}