/* ============================================================
   凤凰体育主站 · 共享样式表 /assets/site.css
   夜场黑底 · 炽金主线 · 电光青数据 · 霓虹紫标签
   ============================================================ */

/* ---------- 1. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h, 78px) + 20px);
}

body,
h1, h2, h3, h4, h5, p, ul, ol, li, figure, blockquote, dl, dd { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; width: 100%; }

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 3px;
}

/* ---------- 2. 设计变量 ---------- */
:root {
  --night: #07090C;
  --char: #10141A;
  --char-2: #161C24;

  --gold: #F2A93B;
  --gold-lift: #FFD98A;
  --gold-deep: #8A5A18;
  --cyan: #38E1D0;
  --violet: #A46BFF;
  --paper: #F5F1E8;
  --silver: #A7B0BD;
  --alert: #FF5A3C;

  --gold-line: rgba(242, 169, 59, 0.26);
  --gold-soft: rgba(242, 169, 59, 0.08);
  --hair: rgba(245, 241, 232, 0.10);

  --font-sans: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo,
    Consolas, monospace;

  --shell: 1320px;
  --gutter: clamp(18px, 4.4vw, 56px);
  --header-h: 78px;

  --step-cover: clamp(2.4rem, 7vw, 7.5rem);
  --step-section: clamp(1.6rem, 3.2vw, 2.6rem);
  --step-body: 1.05rem;
  --step-note: 0.8rem;

  --radius-lg: 22px;
  --radius-md: 14px;
  --radius-sm: 8px;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

@media (max-width: 1080px) {
  :root { --header-h: 64px; }
}

/* ---------- 3. 页面基底 ---------- */
body {
  min-height: 100dvh;
  background: var(--night);
  color: var(--paper);
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.75;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(920px 640px at 84% -10%, rgba(242, 169, 59, 0.11), transparent 62%),
    radial-gradient(780px 540px at 4% 6%, rgba(164, 107, 255, 0.075), transparent 60%),
    linear-gradient(180deg, #07090C 0%, #080B10 48%, #07090C 100%);
}

body[data-nav-open="true"] { overflow: hidden; }

/* ---------- 4. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  left: 14px;
  top: -80px;
  z-index: 200;
  padding: 10px 18px;
  border-radius: 0 0 12px 12px;
  background: var(--gold);
  color: #1A1104;
  font-weight: 700;
  font-size: 0.9rem;
  transition: top 0.18s var(--ease);
}
.skip-link:focus { top: 0; }

/* ---------- 5. 头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  background: linear-gradient(180deg, rgba(10, 13, 18, 0.97), rgba(7, 9, 12, 0.93));
  border-bottom: 1px solid var(--gold-line);
  transition: background 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.site-header[data-scrolled="true"] {
  background: rgba(7, 9, 12, 0.985);
  box-shadow: 0 26px 48px -34px #000;
}

.header-rail {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 28px);
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
  min-height: var(--header-h);
  transition: min-height 0.3s var(--ease);
}
.site-header[data-scrolled="true"] .header-rail {
  min-height: calc(var(--header-h) - 14px);
}

.brand-cluster {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.4vw, 20px);
  min-width: 0;
}

.brand-mark {
  display: flex;
  align-items: center;
  gap: 11px;
  min-width: 0;
}

.brand-glyph {
  position: relative;
  flex: none;
  width: 34px;
  height: 34px;
  border-radius: 12px 12px 12px 2px;
  transform: rotate(-45deg);
  background: conic-gradient(from 210deg, var(--gold-deep), var(--gold), var(--gold-lift), var(--gold-deep));
  box-shadow: 0 0 0 1px rgba(255, 217, 138, 0.35), 0 14px 28px -16px rgba(242, 169, 59, 0.9);
}
.brand-glyph::after {
  content: "";
  position: absolute;
  inset: 10px;
  border-radius: 50%;
  background: var(--night);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
  min-width: 0;
}
.brand-name {
  font-size: 1.06rem;
  font-weight: 900;
  letter-spacing: 0.01em;
  color: var(--paper);
}
.brand-sub {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--silver);
  white-space: nowrap;
}

.status-dot {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px 6px 10px;
  border: 1px solid var(--hair);
  border-radius: 999px;
  background: rgba(56, 225, 208, 0.05);
  color: var(--silver);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  white-space: nowrap;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease), background 0.2s var(--ease);
}
.status-dot:hover { border-color: rgba(56, 225, 208, 0.42); color: var(--paper); }
.status-dot[aria-expanded="true"] {
  border-color: rgba(56, 225, 208, 0.6);
  background: rgba(56, 225, 208, 0.12);
  color: var(--paper);
}

.status-pulse {
  position: relative;
  flex: none;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--cyan);
  animation: status-breathe 2s ease-in-out infinite;
}
@keyframes status-breathe {
  0%   { box-shadow: 0 0 0 0 rgba(56, 225, 208, 0.55); }
  70%  { box-shadow: 0 0 0 9px rgba(56, 225, 208, 0); }
  100% { box-shadow: 0 0 0 0 rgba(56, 225, 208, 0); }
}

.header-end {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.8vw, 26px);
  margin-left: auto;
  min-width: 0;
}

.primary-nav { position: relative; }

.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(6px, 1.4vw, 20px);
}

.nav-link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 8px 2px;
  font-size: 0.92rem;
  font-weight: 700;
  color: rgba(245, 241, 232, 0.72);
  transition: color 0.18s var(--ease);
}
.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 100%;
  bottom: 2px;
  height: 2px;
  background: var(--gold);
  transition: right 0.24s var(--ease);
}
.nav-link:hover { color: var(--gold-lift); }
.nav-link:hover::after { right: 0; }
.nav-link[aria-current="page"] { color: var(--gold); }
.nav-link[aria-current="page"]::after {
  right: 0;
  background: linear-gradient(90deg, var(--gold), var(--gold-lift));
}

.nav-index {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.6rem;
  letter-spacing: 0.06em;
  color: var(--gold-deep);
}
.nav-link[aria-current="page"] .nav-index { color: var(--gold); }
.nav-label { white-space: nowrap; }

.header-tools {
  display: flex;
  align-items: center;
  gap: clamp(8px, 1.2vw, 16px);
  padding-left: clamp(12px, 1.6vw, 22px);
  border-left: 1px solid var(--hair);
}

.tool-link {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  color: var(--silver);
  white-space: nowrap;
  padding: 6px 2px;
  transition: color 0.18s var(--ease);
}
.tool-link:hover { color: var(--cyan); }

.header-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  padding: 0.6em 1.15em;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--gold-lift), var(--gold));
  color: #1A1104;
  font-size: 0.86rem;
  font-weight: 700;
  white-space: nowrap;
  transition: transform 0.18s var(--ease), box-shadow 0.18s var(--ease);
}
.header-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 18px 34px -18px rgba(242, 169, 59, 0.9);
}

.nav-toggle {
  display: none;
  position: relative;
  flex: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--gold-line);
  border-radius: 12px;
  background: var(--gold-soft);
  transition: border-color 0.2s var(--ease), background 0.2s var(--ease);
}
.nav-toggle:hover { border-color: var(--gold); }
.nav-toggle-bar {
  position: absolute;
  left: 11px;
  right: 11px;
  height: 2px;
  border-radius: 2px;
  background: var(--paper);
  transition: transform 0.24s var(--ease), opacity 0.2s var(--ease);
}
.nav-toggle-bar:nth-child(1) { top: 14px; }
.nav-toggle-bar:nth-child(2) { top: 20px; }
.nav-toggle-bar:nth-child(3) { top: 26px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* 头部面板 */
.header-panel {
  position: absolute;
  top: calc(100% + 1px);
  left: 50%;
  transform: translateX(-50%);
  width: min(680px, calc(100vw - 32px));
  padding: clamp(18px, 2.4vw, 28px);
  border: 1px solid var(--gold-line);
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  background: linear-gradient(180deg, rgba(16, 20, 26, 0.99), rgba(7, 9, 12, 0.99));
  box-shadow: 0 46px 84px -52px #000;
  animation: panel-in 0.22s var(--ease);
}
.header-panel[hidden] { display: none; }
@keyframes panel-in {
  from { opacity: 0; transform: translateX(-50%) translateY(-6px); }
  to   { opacity: 1; transform: translateX(-50%) translateY(0); }
}

.panel-kicker {
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold);
}

.panel-list { display: grid; gap: 10px; }
.panel-list--grid { grid-template-columns: repeat(auto-fit, minmax(148px, 1fr)); }

.panel-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.86rem;
  line-height: 1.65;
  color: rgba(245, 241, 232, 0.8);
}

.panel-link {
  display: block;
  padding: 9px 12px;
  border: 1px solid transparent;
  border-radius: 10px;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--paper);
  transition: border-color 0.18s var(--ease), background 0.18s var(--ease), color 0.18s var(--ease);
}
.panel-link:hover {
  border-color: var(--gold-line);
  background: var(--gold-soft);
  color: var(--gold-lift);
}

.panel-note {
  margin-top: 14px;
  font-size: 0.78rem;
  line-height: 1.7;
  color: var(--silver);
}

.state-tag {
  flex: none;
  margin-top: 4px;
  padding: 0.2em 0.5em;
  border: 1px solid currentColor;
  border-radius: 6px;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.12em;
  line-height: 1.4;
}
.state-tag--live { color: var(--cyan); background: rgba(56, 225, 208, 0.09); }
.state-tag--gray { color: var(--violet); background: rgba(164, 107, 255, 0.09); }
.state-tag--warn { color: var(--alert); background: rgba(255, 90, 60, 0.09); }

.scroll-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--gold-deep), var(--gold), var(--gold-lift), var(--cyan));
  opacity: 0.9;
  pointer-events: none;
}

/* ---------- 6. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 8vw, 120px);
  overflow: hidden;
  border-top: 1px solid var(--gold-line);
  background: linear-gradient(180deg, var(--night) 0%, var(--char) 44%, #0B0F14 100%);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -150px;
  right: -120px;
  width: 440px;
  height: 440px;
  border-radius: 50%;
  background: radial-gradient(circle at 42% 42%, rgba(242, 169, 59, 0.16), transparent 68%);
  pointer-events: none;
}

.footer-shell {
  position: relative;
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(44px, 7vw, 88px) var(--gutter) 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
  gap: clamp(28px, 4vw, 64px);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 20px;
  min-width: 0;
}

.footer-contact { display: grid; gap: 12px; }

.contact-key {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--silver);
}
.contact-value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.86rem;
  line-height: 1.6;
  color: var(--paper);
  word-break: break-word;
}

.footer-note {
  max-width: 42ch;
  font-size: 0.78rem;
  line-height: 1.7;
  color: var(--silver);
}

.footer-index {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(18px, 2.4vw, 34px);
}

.footer-col { min-width: 0; }

.footer-col-title {
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gold);
}

.footer-list { display: grid; gap: 9px; }

.footer-link {
  display: inline-block;
  font-size: 0.9rem;
  color: rgba(245, 241, 232, 0.74);
  transition: color 0.18s var(--ease), transform 0.18s var(--ease);
}
.footer-link:hover { color: var(--gold-lift); transform: translateX(4px); }

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 26px;
  margin-top: clamp(30px, 4vw, 56px);
  padding: 22px 0 34px;
  border-top: 1px solid var(--hair);
}
.footer-legal-note {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--silver);
}

/* ---------- 7. 布局与通用排版 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  position: relative;
  padding-block: clamp(56px, 9vw, 132px);
}
.section--tight { padding-block: clamp(34px, 5vw, 72px); }
.section--char { background: var(--char); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 18px 32px;
  margin-bottom: clamp(24px, 3.4vw, 48px);
}

.kicker {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold);
}

.display-xl {
  font-size: var(--step-cover);
  font-weight: 900;
  line-height: 0.95;
  letter-spacing: -0.02em;
}
.display-lg {
  font-size: var(--step-section);
  font-weight: 900;
  line-height: 1.06;
  letter-spacing: -0.015em;
}

.lede {
  max-width: 62ch;
  font-size: clamp(1rem, 1.5vw, 1.18rem);
  line-height: 1.85;
  color: rgba(245, 241, 232, 0.78);
}

.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
  letter-spacing: -0.01em;
}

.rule {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, var(--gold-line), rgba(242, 169, 59, 0));
}

/* 栅格 */
.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2.4vw, 32px);
}
.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }
.span-7 { grid-column: span 7; }
.span-8 { grid-column: span 8; }
.span-9 { grid-column: span 9; }

/* ---------- 8. 按钮与标记 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6em;
  padding: 0.82em 1.5em;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 0.95rem;
  font-weight: 700;
  line-height: 1.2;
  transition: transform 0.18s var(--ease), box-shadow 0.18s var(--ease),
    border-color 0.18s var(--ease), background 0.18s var(--ease), color 0.18s var(--ease);
}
.btn--primary {
  background: linear-gradient(135deg, var(--gold-lift), var(--gold));
  color: #1A1104;
  box-shadow: 0 16px 36px -22px rgba(242, 169, 59, 0.9);
}
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 22px 44px -20px rgba(242, 169, 59, 0.95); }
.btn--ghost {
  border-color: var(--gold-line);
  background: var(--gold-soft);
  color: var(--gold-lift);
}
.btn--ghost:hover { border-color: var(--gold); background: rgba(242, 169, 59, 0.16); }
.btn--quiet {
  border-color: var(--hair);
  color: var(--paper);
}
.btn--quiet:hover { border-color: var(--cyan); color: var(--cyan); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  padding: 0.34em 0.72em;
  border: 1px solid var(--gold-line);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--gold);
}
.tag--cyan { border-color: rgba(56, 225, 208, 0.36); color: var(--cyan); }
.tag--violet { border-color: rgba(164, 107, 255, 0.36); color: var(--violet); }

/* ---------- 9. 卡片与数据 ---------- */
.card {
  position: relative;
  padding: clamp(20px, 2.6vw, 32px);
  border: 1px solid var(--hair);
  border-radius: var(--radius-lg);
  background: linear-gradient(180deg, rgba(22, 28, 36, 0.92), rgba(16, 20, 26, 0.94));
}
.card--gold {
  border-color: var(--gold-line);
  background: linear-gradient(160deg, rgba(242, 169, 59, 0.12), rgba(16, 20, 26, 0.94) 58%);
}
.card--floating { box-shadow: 0 42px 86px -54px rgba(0, 0, 0, 0.95); }

.stat { display: flex; flex-direction: column; gap: 0.3em; }

.stat-value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(2rem, 5vw, 3.4rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--paper);
}
.stat-value--gold { color: var(--gold); }
.stat-value--cyan { color: var(--cyan); }

.stat-label {
  font-family: var(--font-mono);
  font-size: var(--step-note);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--silver);
}

/* ---------- 10. 坐标索引轨道 ---------- */
.index-rail {
  display: flex;
  flex-direction: column;
  padding-left: 18px;
  border-left: 1px solid var(--gold-line);
}
.index-step {
  display: flex;
  gap: 14px;
  padding: 12px 0;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  color: var(--silver);
  border-bottom: 1px solid var(--hair);
}
.index-step:last-child { border-bottom: 0; }

/* ---------- 11. 面包屑 ---------- */
.breadcrumb { margin-bottom: clamp(20px, 3vw, 34px); }

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5em;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.14em;
  color: var(--silver);
}
.breadcrumb-list li + li::before {
  content: "/";
  margin-right: 0.5em;
  color: var(--gold-deep);
}
.breadcrumb-list a:hover { color: var(--gold-lift); }
.breadcrumb-list [aria-current="page"] { color: var(--paper); }

/* ---------- 12. 正文 ---------- */
.prose {
  max-width: 72ch;
  font-size: var(--step-body);
  line-height: 1.85;
  color: rgba(245, 241, 232, 0.82);
}
.prose > * + * { margin-top: 1.35em; }
.prose h2 {
  font-size: clamp(1.3rem, 2.2vw, 1.75rem);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--paper);
}
.prose h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--paper);
}
.prose strong { font-weight: 700; color: var(--paper); }
.prose a {
  color: var(--gold-lift);
  border-bottom: 1px solid var(--gold-line);
}
.prose a:hover { border-bottom-color: var(--gold); }
.prose li { position: relative; padding-left: 1.4em; }
.prose li + li { margin-top: 0.6em; }
.prose li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--gold-deep);
}
.prose ul, .prose ol { padding-left: 0; }

/* ---------- 13. 可展开内容组 ---------- */
.expand-group { border-top: 1px solid var(--hair); }

.expand-item { border-bottom: 1px solid var(--hair); }

.expand-trigger {
  display: flex;
  align-items: center;
  gap: 18px;
  width: 100%;
  padding: clamp(16px, 2vw, 22px) 0;
  text-align: left;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--paper);
  transition: color 0.18s var(--ease);
}
.expand-trigger:hover { color: var(--gold-lift); }
.expand-trigger[aria-expanded="true"] { color: var(--gold); }

.expand-sign {
  position: relative;
  flex: none;
  margin-left: auto;
  width: 20px;
  height: 20px;
  border: 1px solid var(--gold-line);
  border-radius: 50%;
  transition: transform 0.24s var(--ease), border-color 0.24s var(--ease);
}
.expand-sign::before,
.expand-sign::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 9px;
  height: 1.5px;
  background: var(--gold);
  transform: translate(-50%, -50%);
}
.expand-sign::after { transform: translate(-50%, -50%) rotate(90deg); }
.expand-trigger[aria-expanded="true"] .expand-sign { transform: rotate(135deg); border-color: var(--gold); }

.expand-panel {
  padding-bottom: 20px;
  max-width: 72ch;
  font-size: var(--step-body);
  line-height: 1.85;
  color: rgba(245, 241, 232, 0.78);
  animation: panel-in-soft 0.24s var(--ease);
}
.expand-panel[hidden] { display: none; }
@keyframes panel-in-soft {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* ---------- 14. 图片容器 ---------- */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  border: 1px solid var(--hair);
  border-radius: var(--radius-lg);
  background: linear-gradient(140deg, var(--char-2), var(--night));
  isolation: isolate;
}
.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.92) contrast(1.06);
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(120% 84% at 12% 0%, rgba(242, 169, 59, 0.18), transparent 58%),
    linear-gradient(180deg, rgba(7, 9, 12, 0) 44%, rgba(7, 9, 12, 0.74) 100%);
}
.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--panorama { aspect-ratio: 21 / 9; }
.media-frame--portrait { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame__caption {
  position: absolute;
  left: 0;
  bottom: 0;
  z-index: 2;
  padding: clamp(14px, 2vw, 24px);
  font-family: var(--font-mono);
  font-size: var(--step-note);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gold-lift);
}

/* ---------- 15. 显现动效 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}
[data-reveal][data-reveal-state="in"] {
  opacity: 1;
  transform: none;
}

/* ---------- 16. 响应式：平板与手机 ---------- */
@media (max-width: 1080px) {
  .nav-toggle { display: block; }

  .header-tools .tool-link { display: none; }

  .primary-nav {
    position: fixed;
    left: 0;
    right: 0;
    top: var(--header-h);
    max-height: calc(100dvh - var(--header-h));
    overflow-y: auto;
    overscroll-behavior: contain;
    padding: clamp(14px, 4vw, 26px) var(--gutter) clamp(28px, 6vw, 48px);
    background: linear-gradient(180deg, rgba(12, 16, 21, 0.99), rgba(7, 9, 12, 1));
    border-top: 1px solid var(--gold-line);
    border-bottom: 1px solid var(--gold-line);
    transform: translateY(-10px);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.22s var(--ease), transform 0.22s var(--ease), visibility 0.22s;
  }
  .primary-nav[data-open="true"] {
    transform: none;
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }

  .nav-list { flex-direction: column; align-items: stretch; gap: 0; }
  .nav-item { border-bottom: 1px solid var(--hair); }
  .nav-item:last-child { border-bottom: 0; }
  .nav-link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 16px 4px;
    font-size: clamp(1.35rem, 6vw, 1.9rem);
    font-weight: 900;
    letter-spacing: -0.01em;
    color: var(--paper);
  }
  .nav-link::after { display: none; }
  .nav-link[aria-current="page"] { color: var(--gold); }
  .nav-index { font-size: 0.74rem; letter-spacing: 0.14em; color: var(--gold); }

  body[data-nav-open="true"] { overflow: hidden; }

  .header-panel {
    left: var(--gutter);
    right: var(--gutter);
    width: auto;
    transform: none;
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
    max-height: calc(100dvh - var(--header-h) - 20px);
    overflow-y: auto;
  }
  @keyframes panel-in {
    from { opacity: 0; transform: translateY(-6px); }
    to   { opacity: 1; transform: translateY(0); }
  }
}

@media (max-width: 900px) {
  .footer-grid { grid-template-columns: 1fr; }
}

@media (max-width: 860px) {
  .grid-12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }
  .span-3, .span-4, .span-5, .span-6, .span-7, .span-8, .span-9 { grid-column: 1 / -1; }
  .footer-index { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 720px) {
  .status-label { display: none; }
  .status-dot { padding: 7px 10px; }
}

@media (max-width: 640px) {
  .brand-sub { display: none; }
  .brand-glyph { width: 30px; height: 30px; }
  .header-cta { padding: 0.5em 0.9em; font-size: 0.78rem; }
  .header-panel { width: auto; }
  .media-frame--portrait { aspect-ratio: 4 / 5; }
  .footer-legal { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 380px) {
  .header-cta { display: none; }
}

/* ---------- 17. 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

  [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }

  .status-pulse { box-shadow: none !important; }
}