/* ====== RESET & BASE ====== */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/**
 * 浅色模式主题变量（默认）
 */
:root {
  --bg: #f3f4f6;
  --bg2: #fff;
  --bg3: #e5e7eb;
  --bg4: #d1d5db;
  --bg5: #9ca3af;
  --card: #fff;
  --card2: #f9fafb;
  --card-result: #fff;
  --border: #e5e7eb;
  --border2: #d1d5db;
  --accent: #1e40af;
  --accent2: #3b82f6;
  --accent-glow: rgb(30 64 175 / 12%);
  --text: #1f2937;
  --text2: #5b6370;
  --text3: #6b7280;
  --yellow: #fbbf24;
  --green: #10b981;
  --blue: #3b82f6;
  --purple: #8b5cf6;
  --orange: #f59e0b;
  --teal: #14b8a6;
  --red: #ef4444;
  --font: "Noto Sans SC", system-ui, sans-serif;
  --transition-theme: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

/**
 * 深色模式主题变量
 */
:root[data-theme="dark"] {
  --bg: #06080f;
  --bg2: #0c1220;
  --bg3: #111827;
  --bg4: #1a2332;
  --bg5: #1e2a3a;
  --card: #0f1923;
  --card2: #141f2e;
  --card-result: #1a2332;
  --border: #1e2d42;
  --border2: #243550;
  --accent: #e94560;
  --accent2: #ff6b8a;
  --accent-glow: rgb(233 69 96 / 12%);
  --text: #e8eaf0;
  --text2: #b0b8c8;
  --text3: #8b95a8;
  --yellow: #ffd166;
  --green: #06d6a0;
  --blue: #4cc9f0;
  --purple: #c77dff;
  --orange: #ff9f43;
  --teal: #00b4d8;
  --red: #ef476f;
}

html {
  scroll-behavior: smooth;
}

/* Skip link for accessibility */
.skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  background: var(--accent);
  color: #fff;
  padding: 8px 16px;
  z-index: 9999;
  font-size: 0.9rem;
  border-radius: 0 0 4px;
  text-decoration: none;
}

.skip-link:focus {
  top: 0;
}

/* Screen reader only */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  transition: var(--transition-theme);
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: var(--font);
  cursor: pointer;
}

img {
  max-width: 100%;
}

/* ====== SCROLLBAR ====== */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--border2);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent);
}

/* ====== LAYOUT ====== */
.container {
  max-width: 1060px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 56px 0;
}

.section-sm {
  padding: 48px 0;
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 14px;
}

.section-label .dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%,
  100% {
    opacity: 1;
    transform: scale(1);
  }

  50% {
    opacity: 0.4;
    transform: scale(0.7);
  }
}

.section-title {
  font-size: clamp(1.5rem, 3.5vw, 2.1rem);
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 12px;
  color: var(--text);
}

.section-desc {
  color: var(--text2);
  font-size: 0.95rem;
  max-width: 560px;
  line-height: 1.7;
}

/* ====== NAV ====== */
#nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--card);
  backdrop-filter: blur(16px) saturate(1.8);
  -webkit-backdrop-filter: blur(16px) saturate(1.8);
  border-bottom: 1px solid var(--border);
  transition:
    var(--transition-theme),
    box-shadow 0.3s ease;
}

#nav .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 13px;
  padding-bottom: 13px;
}

.nav-logo {
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

.nav-links a {
  color: var(--text3);
  font-size: 0.85rem;
  transition: color 0.2s;
  padding: 4px 0;
  position: relative;
}

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transition: transform 0.25s;
}

.nav-links a:hover {
  color: var(--text);
}

.nav-links a:hover::after {
  transform: scaleX(1);
}

.nav-cta {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 8px 20px;
  font-size: 0.85rem;
  font-weight: 600;
  transition: all 0.2s;
  letter-spacing: 0.02em;
}

.nav-cta:hover {
  background: var(--accent2);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px var(--accent-glow);
}

/* ====== THEME TOGGLE ====== */
.theme-toggle {
  background: transparent;
  border: 1px solid var(--border2);
  border-radius: 8px;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s ease;
  margin-right: 12px;
  flex-shrink: 0;
}

.theme-toggle:hover {
  border-color: var(--accent);
  background: var(--accent-glow);
  transform: rotate(15deg);
}

.theme-icon {
  font-size: 1.2rem;
  line-height: 1;
  transition: transform 0.3s ease;
}

.theme-toggle:active .theme-icon {
  transform: rotate(180deg);
}

/* ====== HERO ====== */
#hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding: 100px 0 80px;
}

.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(ellipse 80% 60% at 50% -10%, var(--accent-glow) 0%, transparent 70%),
    radial-gradient(ellipse 50% 40% at 80% 60%, rgb(76 201 240 / 4%) 0%, transparent 60%),
    radial-gradient(ellipse 40% 30% at 20% 80%, rgb(199 125 255 / 3%) 0%, transparent 60%);
}

.hero-grid {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, black 30%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse 80% 80% at 50% 50%, black 30%, transparent 80%);
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 820px;
  margin: 0 auto;
  text-align: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--accent-glow);
  border: 1px solid var(--accent);
  border-radius: 100px;
  padding: 6px 16px;
  font-size: 0.78rem;
  color: var(--accent2);
  font-weight: 500;
  margin-bottom: 28px;
  letter-spacing: 0.02em;
}

.hero-badge .badge-dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse-dot 1.5s ease-in-out infinite;
}

.hero-title {
  font-size: clamp(2.2rem, 7vw, 4rem);
  font-weight: 800;
  line-height: 1.12;
  margin-bottom: 22px;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--text) 30%, var(--accent) 70%, var(--accent2) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  font-size: 1.05rem;
  color: var(--text2);
  margin-bottom: 36px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.92rem;
  transition: all 0.25s;
  border: none;
  letter-spacing: 0.01em;
}

.btn-p {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 4px 20px var(--accent-glow);
}

.btn-p:hover {
  background: var(--accent2);
  transform: translateY(-2px);
  box-shadow: 0 8px 28px var(--accent-glow);
}

.btn-s {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border2);
}

.btn-s:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-glow);
}

.hero-stats {
  display: flex;
  gap: 32px;
  justify-content: center;
  margin-top: 56px;
  flex-wrap: wrap;
}

.hero-stat {
  text-align: center;
}

.hero-stat .num {
  font-size: 1.8rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: block;
}

.hero-stat .lbl {
  font-size: 0.78rem;
  color: var(--text3);
  letter-spacing: 0.05em;
}

/* ====== CARD ====== */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px;
  opacity: 0;
  transform: translateY(20px);
  transition:
    opacity 0.5s ease,
    transform 0.5s ease,
    var(--transition-theme),
    box-shadow 0.3s;
}

.card:hover {
  border-color: var(--accent);
  box-shadow: 0 8px 24px var(--accent-glow);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  cursor: pointer;
  user-select: none;
  margin: -4px -4px 0;
  padding: 16px 20px;
  border-radius: 12px;
  transition: background 0.2s;
}

.card-header:hover {
  background: var(--accent-glow);
}

.card-header h2 {
  font-size: 1.2rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 10px;
}

.card-header .card-icon {
  font-size: 1.4rem;
}

.card-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  border-radius: 20px;
  background: var(--accent-glow);
  color: var(--accent2);
  font-size: 0.78rem;
  border: 1px solid var(--accent);
  transition: all 0.25s;
  white-space: nowrap;
  align-self: center;
  flex-shrink: 0;
}

.card-toggle:hover {
  background: var(--accent);
  color: #fff;
}

.card-toggle .arr {
  font-size: 0.7rem;
  transition: transform 0.3s;
}

.card-toggle.open .arr {
  transform: rotate(180deg);
}

.card-body {
  display: none;
  padding: 4px;
}

.card-body.open {
  display: block;
}

/* ====== MODULE DIVIDER ====== */
.mod-sep {
  border: none;
  border-top: 1px solid var(--border);
  margin: 0 auto;
  max-width: 1060px;
}

/* ====== VISUAL TIMELINE (SVG) ====== */
.visual-timeline-wrap {
  margin-top: 28px;
  overflow-x: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

.visual-timeline {
  min-width: 600px;
}

.vt-svg {
  width: 100%;
  height: auto;
  display: block;
}

.vt-axis {
  stroke: var(--border2);
  stroke-width: 2;
}

.vt-axis-label {
  fill: var(--text3);
  font-size: 10px;
  text-anchor: middle;
}

.vt-win-label {
  font-family: var(--font);
}

.vt-age-dot {
  cursor: pointer;
  transition:
    r 0.2s ease,
    opacity 0.2s ease;
}

.vt-age-dot:hover {
  opacity: 0.8;
  transform: scale(1.2);
}

.vt-tooltip-bg {
  fill: var(--card);
  stroke: var(--border);
}

.vt-tooltip-text {
  fill: var(--text);
  font-family: var(--font);
}

.vt-tooltip-sub {
  fill: var(--text2);
  font-family: var(--font);
}

/* Timeline detail panel */
.tl-detail-panel {
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}

/* ====== TIMELINE ====== */
.tl {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin-top: 24px;
}

.tl-item {
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: 0;
  position: relative;
}

.tl-age {
  padding: 18px 16px 18px 0;
  text-align: right;
  position: relative;
}

.tl-age::before {
  content: "";
  position: absolute;
  top: 22px;
  right: -5px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg);
  box-shadow: 0 0 0 3px var(--accent-glow);
  z-index: 1;
}

.tl-age .age-num {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--accent);
  line-height: 1;
  display: block;
}

.tl-age .age-lbl {
  font-size: 0.72rem;
  color: var(--text3);
  margin-top: 4px;
}

.tl-line {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 104px;
  width: 1px;
  background: var(--border);
}

.tl-item:first-child .tl-line {
  top: 22px;
}

.tl-item:last-child .tl-line {
  bottom: calc(100% - 22px);
}

.tl-content {
  padding: 16px 0 24px 24px;
}

.tl-tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 6px;
  font-size: 0.75rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.tag-red {
  background: rgb(239 71 111 / 15%);
  color: var(--red);
}

.tag-yellow {
  background: rgb(255 209 102 / 15%);
  color: var(--yellow);
}

.tag-green {
  background: rgb(6 214 160 / 12%);
  color: var(--green);
}

.tl-title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.tl-desc {
  font-size: 0.85rem;
  color: var(--text2);
  line-height: 1.7;
  margin-bottom: 8px;
}

.tl-detail-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-top: 12px;
}

.tl-detail-item {
  font-size: 0.8rem;
  padding: 8px 10px;
  background: var(--card2);
  border-radius: 8px;
  border: 1px solid var(--border);
}

.tl-detail-item strong {
  display: block;
  color: var(--text);
  margin-bottom: 2px;
}

.tl-detail-item span {
  color: var(--text3);
}

.tl-detail-item.danger {
  border-color: rgb(239 71 111 / 30%);
  background: rgb(239 71 111 / 5%);
  color: var(--red);
}

.tl-detail-item.warning {
  border-color: rgb(255 209 102 / 20%);
  background: rgb(255 209 102 / 5%);
  color: var(--yellow);
}

.tl-detail-item.ok {
  border-color: rgb(6 214 160 / 20%);
  background: rgb(6 214 160 / 5%);
  color: var(--green);
}

/* ====== 时间线简略版/详情版切换 ====== */
.tl-summary {
  transition: all 0.3s ease;
}

.tl-detail {
  display: none;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transform: translateY(-10px);
  transition:
    max-height 0.4s ease,
    opacity 0.4s ease,
    transform 0.4s ease;
  margin-top: 8px;
}

.tl-detail.expanded {
  display: block;
  max-height: 1000px;
  opacity: 1;
  transform: translateY(0);
}

.tl-toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: 20px;
  background: var(--accent-glow);
  color: var(--accent2);
  font-size: 0.78rem;
  border: 1px solid var(--accent);
  transition: all 0.25s;
  cursor: pointer;
  margin-top: 8px;
}

.tl-toggle-btn:hover {
  background: var(--accent);
  color: #fff;
}

.tl-toggle-btn .tl-toggle-icon {
  font-size: 0.7rem;
  transition: transform 0.3s ease;
}

.tl-toggle-btn.expanded .tl-toggle-icon {
  transform: rotate(180deg);
}

/* ====== CALCULATOR ====== */
.calc-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-top: 20px;
}

.calc-box {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 22px;
}

.calc-box h3 {
  font-size: 0.92rem;
  font-weight: 700;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.calc-inputs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  align-items: center;
}

.calc-inputs input {
  padding: 10px 14px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font-size: 0.9rem;
  transition: border-color 0.2s;
  width: 120px;
}

.calc-inputs input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.calc-inputs input::placeholder {
  color: var(--text3);
}

.result-box {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px;
  margin-top: 14px;
  display: none;
}

.result-box.show {
  display: block;
}

.result-age {
  font-size: 2.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.result-phase {
  font-size: 0.9rem;
  color: var(--text2);
  margin-top: 6px;
}

.result-w {
  font-size: 0.78rem;
  color: var(--text3);
  margin-top: 8px;
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

/* ====== RACE FILTER ====== */
.race-tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}

.race-tab {
  padding: 7px 18px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text3);
  cursor: pointer;
  font-size: 0.82rem;
  transition: all 0.2s;
  font-weight: 500;
}

.race-tab:hover {
  border-color: var(--border2);
  color: var(--text2);
}

.race-tab.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

/* ====== RESEARCH ====== */
.research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
  margin-top: 20px;
}

.research-card {
  background: var(--card2);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 22px;
  transition: all 0.3s;
}

.research-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px var(--accent-glow);
  border-color: var(--accent);
}

.research-card-icon {
  font-size: 2rem;
  margin-bottom: 14px;
}

.research-card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 10px;
  line-height: 1.4;
}

.research-card p {
  font-size: 0.85rem;
  color: var(--text2);
  line-height: 1.7;
}

.research-card .src {
  font-size: 0.75rem;
  color: var(--text3);
  margin-top: 10px;
  display: flex;
  align-items: center;
  gap: 5px;
}

/* ====== ACTIONS ====== */
.action-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 20px;
}

.action-card {
  background: var(--card2);
  border-radius: 14px;
  padding: 22px;
  border: 1px solid transparent;
}

.action-card.urg {
  border-left: 4px solid var(--red);
  background: rgb(239 71 111 / 6%);
}

.action-card.med {
  border-left: 4px solid var(--yellow);
  background: rgb(255 209 102 / 5%);
}

.action-card.low {
  border-left: 4px solid var(--green);
  background: rgb(6 214 160 / 5%);
}

.action-card-badge {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 20px;
  font-size: 0.72rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.action-card.urg .action-card-badge {
  background: rgb(239 71 111 / 15%);
  color: var(--red);
}

.action-card.med .action-card-badge {
  background: rgb(255 209 102 / 15%);
  color: var(--yellow);
}

.action-card.low .action-card-badge {
  background: rgb(6 214 160 / 12%);
  color: var(--green);
}

.action-card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 14px;
}

.action-list {
  list-style: none;
}

.action-list li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.85rem;
}

.action-list li:last-child {
  border-bottom: none;
}

.action-list .act-name {
  color: var(--text2);
}

.action-list .act-deadline {
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 600;
  white-space: nowrap;
}

/* ====== INSIGHT BOX ====== */
.insight-box {
  background: var(--accent-glow);
  border: 1px solid var(--accent);
  border-radius: 14px;
  padding: 28px;
  margin-top: 20px;
  text-align: center;
}

.insight-box p {
  font-size: 0.95rem;
  color: var(--text2);
  line-height: 1.8;
  max-width: 520px;
  margin: 0 auto 16px;
}

.insight-box ul {
  list-style: none;
  text-align: left;
  max-width: 480px;
  margin: 0 auto;
  display: inline-block;
}

.insight-box li {
  padding: 6px 0;
  font-size: 0.88rem;
  color: var(--text2);
  display: flex;
  gap: 10px;
}

.insight-box li::before {
  content: "•";
  color: var(--accent);
  flex-shrink: 0;
}

/* ====== FOOTER ====== */
footer {
  background: var(--bg2);
  border-top: 1px solid var(--border);
  padding: 56px 0;
  text-align: center;
  margin-top: 60px;
}

footer .quote {
  font-style: italic;
  color: var(--text2);
  max-width: 520px;
  margin: 0 auto 14px;
  font-size: 0.92rem;
}

footer p {
  color: var(--text3);
  font-size: 0.82rem;
  margin-bottom: 6px;
}

footer .copy {
  margin-top: 18px;
  font-size: 0.78rem;
}

/* ====== ANIMATIONS ====== */
.fade-up {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity 0.6s ease,
    transform 0.6s ease;
}

.fade-up.vis {
  opacity: 1;
  transform: translateY(0);
}

.card.vis {
  opacity: 1;
  transform: translateY(0);
}

/* ====== RESPONSIVE ====== */
@media (width <= 768px) {
  .nav-links {
    display: none;
  }

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

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

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

  .tl-item {
    grid-template-columns: 80px 1fr;
  }

  .tl-line {
    left: 84px;
  }
}

/* ====== REDUCED MOTION ====== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms;
    animation-iteration-count: 1;
    transition-duration: 0.01ms;
    scroll-behavior: auto;
  }

  .fade-up {
    opacity: 1;
    transform: none;
  }

  .card {
    opacity: 1;
    transform: none;
  }

  .research-card:hover {
    transform: none;
  }
}

/* ====== FOCUS VISIBLE ====== */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ====== IMPROVED MOBILE ====== */
@media (width <= 480px) {
  .hero-stats {
    gap: 20px;
  }

  .hero-stat .num {
    font-size: 1.5rem;
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    justify-content: center;
  }

  .section {
    padding: 40px 0;
  }

  .section-sm {
    padding: 32px 0;
  }

  .card {
    padding: 20px;
  }

  .race-tabs {
    gap: 6px;
  }

  .race-tab {
    padding: 6px 12px;
    font-size: 0.78rem;
  }
}

/* ====== UX IMPROVEMENTS 2026-04-20 ====== */

/* Hero CTA居中 + 大按钮 */
.hero-actions-centered {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  margin: 28px 0 20px;
}

.btn-large {
  font-size: 1.05rem;
  padding: 14px 32px;
  border-radius: 10px;
  font-weight: 600;
  letter-spacing: 0.02em;
  box-shadow: 0 4px 20px rgb(6 214 160 / 30%);
}

/* 滚动进度条已内联在HTML */

/* Quiz区域醒目样式 */
#quiz {
  border-top: 3px solid var(--accent);
  position: relative;
}

#quiz::before {
  content: "👇 从这里开始";
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 3px 12px;
  border-radius: 20px;
  white-space: nowrap;
  letter-spacing: 0.05em;
}

/* 导航栏滚动时加深阴影 */
#nav.scrolled {
  box-shadow: 0 2px 20px rgb(0 0 0 / 12%);
}

/* Timeline内间距收紧 */
#timeline .card {
  margin-bottom: 8px;
}

/* ============================================
   UNIVERSAL WINDOWS CARDS
   人类通用窗口 - 卡片样式
   ============================================ */
.univ-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-6);
  margin-top: var(--space-8);
}

.univ-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-top: 3px solid var(--accent);
  border-radius: var(--radius-lg);
  padding: 0;
  overflow: hidden;
  transition: all 0.3s var(--ease-out);
  opacity: 0;
  transform: translateY(16px);
  display: flex;
  flex-direction: column;
}

.univ-card.in-view {
  opacity: 1;
  transform: translateY(0);
}

.univ-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px var(--accent-glow);
  border-color: var(--accent);
}

.univ-card:nth-child(2) {
  border-top-color: var(--accent-2);
}
.univ-card:nth-child(3) {
  border-top-color: var(--accent-3);
}
.univ-card:nth-child(4) {
  border-top-color: var(--accent);
}
.univ-card:nth-child(5) {
  border-top-color: var(--accent-2);
}
.univ-card:nth-child(6) {
  border-top-color: var(--accent-3);
}

.univ-card-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  padding: 24px 24px 16px;
  cursor: pointer;
  transition: background 0.2s;
}

.univ-card-header:hover {
  background: var(--bg-hover);
}

.univ-card-emoji {
  font-size: 32px;
  line-height: 1;
  margin-bottom: 12px;
}

.univ-card h3 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
  letter-spacing: 0.02em;
  line-height: 1.35;
}

.univ-age-badge {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: 999px;
  white-space: nowrap;
  letter-spacing: 0.05em;
}

.univ-age-badge.early {
  background: var(--status-closed-bg);
  color: var(--status-closed);
  border: 1px solid var(--status-closed-border);
}

.univ-age-badge.mid {
  background: var(--status-closing-bg);
  color: var(--status-closing);
  border: 1px solid var(--status-closing-border);
}

.univ-age-badge.late {
  background: var(--status-open-bg);
  color: var(--status-open);
  border: 1px solid var(--status-open-border);
}

.univ-desc {
  font-size: 15px;
  line-height: 1.65;
  color: var(--text-secondary);
  padding: 0 24px 16px;
}

.univ-expand-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin: 0 24px 20px;
  padding: 6px 14px;
  font-family: var(--font-main);
  font-size: 13px;
  color: var(--accent);
  background: var(--accent-bg);
  border: 1px solid var(--accent);
  border-radius: 999px;
  cursor: pointer;
  align-self: flex-start;
  transition: all 0.2s;
}

.univ-expand-btn:hover {
  background: var(--accent);
  color: var(--text-inverse);
}

.univ-expand-btn .arr {
  display: inline-block;
  font-size: 10px;
  transition: transform 0.3s;
}

.univ-expand-btn.expanded .arr {
  transform: rotate(180deg);
}

.univ-detail {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s var(--ease-out);
  border-top: 1px solid transparent;
}

.univ-detail.open {
  max-height: 1200px;
  border-top-color: var(--border);
}

.univ-detail-inner {
  padding: 20px 24px 24px;
  background: var(--bg2);
}

.univ-detail-grid {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.univ-detail-item {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 12px;
  padding: 10px 14px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-left: 3px solid var(--border-strong);
  border-radius: var(--radius-md);
  font-size: 14px;
  line-height: 1.6;
}

.univ-detail-item.danger {
  border-left-color: var(--status-closed);
  background: var(--status-closed-bg);
}

.univ-detail-item.warning {
  border-left-color: var(--status-closing);
  background: var(--status-closing-bg);
}

.univ-detail-item.ok {
  border-left-color: var(--status-open);
  background: var(--status-open-bg);
}

.univ-detail-item.blue {
  border-left-color: var(--accent-2);
  background: rgb(46 139 87 / 5%);
}

.univ-detail-item.full {
  grid-template-columns: 1fr;
}

.univ-detail-item strong {
  color: var(--text-primary);
  font-weight: 600;
}

.univ-detail-item span {
  color: var(--text-secondary);
}

@media (width <= 768px) {
  .univ-grid {
    grid-template-columns: 1fr;
  }
  .univ-detail-item {
    grid-template-columns: 1fr;
  }
}