/* ==========================================================================
   乐竞体育官网 · 共享样式表 /assets/site.css
   深夜数据演播室 × 草原看台：夜空深蓝底色 + 电光青锚点 + 暖金层级
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body,
h1, h2, h3, h4, h5, h6,
p, figure, blockquote, dl, dd { margin: 0; }

ul, ol { margin: 0; padding: 0; list-style: none; }

img, svg, video { display: block; max-width: 100%; }

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}

[hidden] { display: none !important; }

/* ------------------------------ 2. Tokens ----------------------------- */
:root {
  --night: #070C1C;
  --ink-900: #05070F;
  --panel: #0E1730;
  --panel-2: #16224A;

  --cyan: #2BE0D6;
  --cyan-soft: #7FF3EC;
  --gold: #FFB43C;
  --paper: #F4F7FB;
  --index: #8A94AE;
  --ok: #35D07F;
  --live: #FF5A6E;

  --font-display: "Barlow Condensed", "Oswald", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;

  --maxw: 1280px;
  --radius-lg: 28px;
  --radius-md: 18px;
  --radius-sm: 12px;
  --radius-pill: 999px;

  --gap: clamp(16px, 2vw, 28px);
  --pad-inline: clamp(16px, 4vw, 32px);

  --line: rgba(127, 243, 236, 0.16);
  --line-strong: rgba(43, 224, 214, 0.45);
  --shadow-float: 0 20px 45px -28px rgba(0, 0, 0, 0.95);
}

/* --------------------------- 3. 基础排版 ------------------------------- */
body {
  min-height: 100vh;
  background-color: var(--night);
  background-image:
    radial-gradient(1100px 620px at 82% -12%, rgba(43, 224, 214, 0.14), transparent 68%),
    radial-gradient(760px 520px at 4% 10%, rgba(255, 180, 60, 0.10), transparent 70%),
    linear-gradient(180deg, #070C1C 0%, #050914 100%);
  background-attachment: fixed;
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

::selection { background: var(--cyan); color: #04121A; }

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 6px;
}

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 200;
  padding: 10px 18px;
  border-radius: var(--radius-pill);
  background: var(--cyan);
  color: #04121A;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  transform: translateY(-160%);
  transition: transform 200ms ease-out;
}
.skip-link:focus { transform: translateY(0); }

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* --------------------------- 4. 布局容器 ------------------------------- */
.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--pad-inline);
}

.section { padding-block: clamp(36px, 5vw, 72px); }

.section__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 3.2vw, 36px);
  line-height: 1.15;
  letter-spacing: -0.015em;
}

.section__lead {
  max-width: 44em;
  margin-top: 10px;
  color: rgba(244, 247, 251, 0.72);
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gap);
}

.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-6 { grid-column: span 6; }
.col-8 { grid-column: span 8; }
.col-9 { grid-column: span 9; }
.col-12 { grid-column: span 12; }

/* ------------------------ 5. 索引与正文文本 ---------------------------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}
.eyebrow::before {
  content: "";
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: var(--cyan);
}

.index-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  padding: 12px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: rgba(14, 23, 48, 0.72);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--index);
}

.index-bar__item { display: inline-flex; align-items: center; gap: 8px; }
.index-bar__item + .index-bar__item::before {
  content: "";
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--line-strong);
}

.prose {
  max-width: 38em;
  color: rgba(244, 247, 251, 0.86);
}
.prose > * + * { margin-top: 1em; }
.prose h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(22px, 2.6vw, 30px);
  line-height: 1.2;
  color: var(--paper);
}
.prose h3 { font-size: 18px; font-weight: 600; color: var(--paper); }
.prose strong { color: var(--cyan-soft); }
.prose a { color: var(--cyan); border-bottom: 1px solid var(--line-strong); }
.prose a:hover { color: var(--cyan-soft); border-color: var(--cyan-soft); }
.prose ul, .prose ol { padding-left: 1.3em; }
.prose li { margin-top: 0.4em; list-style: disc; }
.prose ol li { list-style: decimal; }
.prose code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  padding: 1px 6px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: rgba(22, 34, 74, 0.8);
}
.prose blockquote {
  padding-left: 16px;
  border-left: 2px solid var(--cyan);
  color: var(--index);
}

/* ---------------------------- 6. 按钮胶囊 ------------------------------ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 10px 22px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.01em;
  transition: transform 180ms ease-out, background-color 180ms ease-out, border-color 180ms ease-out, color 180ms ease-out;
}
.btn--primary {
  background: var(--cyan);
  color: #04121A;
  box-shadow: 0 14px 32px -18px rgba(43, 224, 214, 0.95);
}
.btn--primary:hover { background: var(--cyan-soft); transform: translateY(-2px); }
.btn--gold { background: var(--gold); color: #2A1700; }
.btn--gold:hover { filter: brightness(1.08); transform: translateY(-2px); }
.btn--ghost { border-color: var(--line-strong); color: var(--cyan-soft); }
.btn--ghost:hover { background: rgba(43, 224, 214, 0.12); color: var(--paper); }

.pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 36px;
  padding: 0 14px;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  font-size: 13px;
  white-space: nowrap;
  transition: background-color 180ms ease-out, border-color 180ms ease-out, color 180ms ease-out, transform 180ms ease-out;
}
.pill--ghost {
  border-color: var(--line-strong);
  background: rgba(43, 224, 214, 0.06);
  color: var(--cyan-soft);
}
.pill--ghost:hover { background: rgba(43, 224, 214, 0.16); color: var(--paper); }
.pill--accent {
  background: var(--cyan);
  color: #04121A;
  font-weight: 700;
}
.pill--accent:hover { background: var(--cyan-soft); transform: translateY(-1px); }
.pill__key {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}
.pill--accent .pill__key { color: #04121A; }
.pill__text { font-weight: 600; }

/* ----------------------------- 7. 面包屑 ------------------------------- */
.breadcrumb { padding-block: 14px; }
.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--index);
}
.breadcrumb__item { display: inline-flex; align-items: center; gap: 8px; }
.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  color: rgba(138, 148, 174, 0.6);
}
.breadcrumb__item a { color: var(--cyan); }
.breadcrumb__item a:hover { color: var(--cyan-soft); }

/* ------------------------- 8. 卡片 / 标签 / 状态 ----------------------- */
.card {
  position: relative;
  padding: clamp(16px, 2vw, 24px);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--panel);
  transition: transform 180ms ease-out, border-color 180ms ease-out, box-shadow 180ms ease-out;
}
.card--lift:hover {
  transform: translateY(-4px);
  border-color: var(--line-strong);
  box-shadow: var(--shadow-float);
}
.card__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.25;
  letter-spacing: -0.01em;
}
.card__meta {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--index);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--cyan-soft);
  background: rgba(43, 224, 214, 0.07);
}
.tag--live {
  color: var(--live);
  border-color: rgba(255, 90, 110, 0.45);
  background: rgba(255, 90, 110, 0.1);
}
.tag--gold {
  color: var(--gold);
  border-color: rgba(255, 180, 60, 0.45);
  background: rgba(255, 180, 60, 0.1);
}

.status-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--index);
}
.status-dot--ok { background: var(--ok); box-shadow: 0 0 0 4px rgba(53, 208, 127, 0.16); }
.status-dot--live { background: var(--live); box-shadow: 0 0 0 4px rgba(255, 90, 110, 0.18); }

/* --------------------------- 9. 图片容器 ------------------------------- */
.media-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(120% 120% at 20% 0%, rgba(43, 224, 214, 0.18), transparent 60%),
    linear-gradient(150deg, var(--panel) 0%, var(--ink-900) 100%);
}
.media-frame > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame__caption {
  position: absolute;
  left: 14px;
  bottom: 12px;
  right: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(244, 247, 251, 0.82);
  text-shadow: 0 2px 12px rgba(5, 7, 15, 0.9);
}

/* ------------------------- 10. 轮次纵向时间轴 -------------------------- */
.axis {
  position: relative;
  padding-left: 34px;
}
.axis::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, rgba(43, 224, 214, 0.75), rgba(127, 243, 236, 0.06));
}
.axis__item {
  position: relative;
  padding-bottom: 22px;
}
.axis__item:last-child { padding-bottom: 0; }
.axis__marker {
  position: absolute;
  left: -34px;
  top: 6px;
  width: 16px;
  height: 16px;
  border: 2px solid var(--cyan);
  border-radius: 50%;
  background: var(--night);
  box-shadow: 0 0 0 4px rgba(43, 224, 214, 0.12);
}
.axis__item[data-state="live"] .axis__marker {
  border-color: var(--live);
  box-shadow: 0 0 0 4px rgba(255, 90, 110, 0.16);
}
.axis__item[data-state="done"] .axis__marker {
  border-color: rgba(138, 148, 174, 0.7);
  box-shadow: none;
}
.axis__body { padding-top: 0; }
.axis__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--index);
}

/* --------------------------- 11. 章节目录 ------------------------------ */
.toc {
  position: sticky;
  top: 96px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: rgba(14, 23, 48, 0.72);
}
.toc__title {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--index);
}
.toc__list { margin-top: 12px; display: grid; gap: 2px; }
.toc__link {
  display: block;
  padding: 8px 12px;
  border-left: 2px solid transparent;
  border-radius: 0 10px 10px 0;
  font-size: 14px;
  color: rgba(244, 247, 251, 0.66);
  transition: color 200ms ease-out, background-color 200ms ease-out, border-color 200ms ease-out;
}
.toc__link:hover { color: var(--paper); background: rgba(43, 224, 214, 0.08); }
.toc__link[aria-current="true"] {
  color: var(--cyan);
  border-left-color: var(--cyan);
  background: rgba(43, 224, 214, 0.12);
}

/* ---------------------------- 12. 手风琴 ------------------------------- */
.accordion {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--panel);
  overflow: hidden;
}
.accordion__item + .accordion__item { border-top: 1px solid var(--line); }
.accordion__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: 100%;
  padding: 16px 18px;
  text-align: left;
  font-size: 16px;
  font-weight: 600;
  color: var(--paper);
  transition: background-color 180ms ease-out, color 180ms ease-out;
}
.accordion__trigger:hover { background: rgba(43, 224, 214, 0.07); }
.accordion__trigger::after {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--cyan);
  transition: transform 200ms ease-out;
}
.accordion__item[data-open] .accordion__trigger { color: var(--cyan); }
.accordion__item[data-open] .accordion__trigger::after { content: "–"; }
.accordion__panel {
  display: none;
  padding: 0 18px 18px;
  color: rgba(244, 247, 251, 0.78);
}
.accordion__item[data-open] .accordion__panel { display: block; }

/* ---------------------------- 13. 标签筛选 ----------------------------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}
.filter-chip {
  padding: 7px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: rgba(244, 247, 251, 0.72);
  transition: background-color 180ms ease-out, border-color 180ms ease-out, color 180ms ease-out;
}
.filter-chip:hover { border-color: var(--line-strong); color: var(--paper); }
.filter-chip[aria-pressed="true"] {
  background: var(--cyan);
  border-color: var(--cyan);
  color: #04121A;
  font-weight: 700;
}
.filter-count {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gold);
}
.filter-count::after { content: " 条"; color: var(--index); }

/* --------------------------- 14. 显现与高亮 ---------------------------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 520ms ease-out, transform 520ms ease-out;
}
[data-reveal].is-visible { opacity: 1; transform: none; }

.is-flash {
  box-shadow: 0 0 0 3px rgba(43, 224, 214, 0.55), 0 0 40px -6px rgba(43, 224, 214, 0.5);
  transition: box-shadow 320ms ease-out;
}

/* ------------------------------ 15. 头部 ------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  padding: 14px clamp(12px, 3vw, 28px) 0;
}
.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(7, 12, 28, 0.94) 0%, rgba(7, 12, 28, 0.74) 58%, rgba(7, 12, 28, 0) 100%);
  pointer-events: none;
}

.header-shell {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.6vw, 20px);
  max-width: var(--maxw);
  margin-inline: auto;
  padding: 8px 8px 8px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: rgba(22, 34, 74, 0.76);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  box-shadow: var(--shadow-float);
  transition: padding 240ms ease-out, background-color 240ms ease-out, border-color 240ms ease-out;
}
.site-header[data-scrolled] .header-shell {
  padding: 6px 6px 6px 12px;
  background: rgba(20, 30, 64, 0.92);
  border-color: var(--line-strong);
}

.brand-island {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  padding: 4px 6px;
  border-radius: var(--radius-pill);
}
.brand-mark {
  position: relative;
  flex: 0 0 auto;
  width: 26px;
  height: 26px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--cyan) 0%, #14A6B4 100%);
  box-shadow: 0 0 0 1px rgba(43, 224, 214, 0.35), 0 0 20px -2px rgba(43, 224, 214, 0.55);
}
.brand-mark::after {
  content: "";
  position: absolute;
  right: -4px;
  bottom: -4px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 12px rgba(255, 180, 60, 0.85);
}
.brand-text { display: grid; gap: 1px; }
.brand-text__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  line-height: 1.1;
  letter-spacing: 0.01em;
  color: var(--paper);
}
.brand-text__line {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--index);
  max-height: 16px;
  transition: opacity 240ms ease-out, max-height 240ms ease-out;
}
.site-header[data-scrolled] .brand-text__line {
  opacity: 0;
  max-height: 0;
  overflow: hidden;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  height: 38px;
  margin-left: auto;
  padding: 0 14px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-pill);
  color: var(--cyan-soft);
  background: rgba(43, 224, 214, 0.07);
}
.nav-toggle__bars {
  position: relative;
  display: block;
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
}
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 200ms ease-out, top 200ms ease-out;
}
.nav-toggle__bars::before { top: -5px; }
.nav-toggle__bars::after { top: 5px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { top: 0; transform: rotate(-45deg); }
.nav-toggle__label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: auto;
  min-width: 0;
}
.site-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
}
.site-nav__item { display: inline-flex; }
.site-nav__link {
  display: inline-flex;
  align-items: center;
  height: 36px;
  padding: 0 13px;
  border-radius: var(--radius-pill);
  font-size: 14px;
  white-space: nowrap;
  color: rgba(244, 247, 251, 0.78);
  transition: background-color 180ms ease-out, color 180ms ease-out;
}
.site-nav__link:hover {
  color: var(--paper);
  background: rgba(43, 224, 214, 0.12);
}
.site-nav__link[aria-current="page"] {
  background: var(--cyan);
  color: #04121A;
  font-weight: 700;
}
.site-nav__actions {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-left: 10px;
  padding-left: 12px;
  border-left: 1px solid var(--line);
}

.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--cyan) 0%, var(--cyan-soft) 55%, var(--gold) 100%);
  transform: scaleX(0);
  transform-origin: 0 50%;
  opacity: 0.9;
  pointer-events: none;
}

/* ------------------------------ 16. 页脚 ------------------------------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 8vw, 96px);
  padding: clamp(40px, 6vw, 72px) var(--pad-inline) clamp(24px, 3vw, 36px);
  background: linear-gradient(180deg, rgba(5, 7, 15, 0) 0%, rgba(10, 16, 34, 0.9) 16%, var(--ink-900) 100%);
  border-top: 1px solid var(--line);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: min(38%, 420px);
  height: 3px;
  background: linear-gradient(90deg, var(--cyan), rgba(43, 224, 214, 0));
}

.footer-shell {
  max-width: var(--maxw);
  margin-inline: auto;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(260px, 5fr) 7fr;
  gap: clamp(28px, 4vw, 64px);
  padding-bottom: clamp(28px, 4vw, 44px);
  border-bottom: 1px solid var(--line);
}

.footer-brand { display: grid; gap: 16px; align-content: start; }
.footer-brand__tag {
  max-width: 22em;
  font-size: 15px;
  color: rgba(244, 247, 251, 0.72);
}
.footer-brand .btn { justify-self: start; }

.footer-index {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(18px, 2.4vw, 32px);
}
.footer-col { display: grid; gap: 12px; align-content: start; }
.footer-col__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: 0.01em;
  color: var(--paper);
}
.footer-col__title::before {
  content: "";
  display: block;
  width: 22px;
  height: 2px;
  margin-bottom: 10px;
  border-radius: 2px;
  background: var(--cyan);
}
.footer-col__list { display: grid; gap: 8px; }
.footer-link {
  font-size: 14px;
  color: rgba(244, 247, 251, 0.7);
  transition: color 180ms ease-out, padding-left 180ms ease-out;
}
.footer-link:hover {
  color: var(--cyan);
  padding-left: 4px;
}

.footer-contact {
  display: grid;
  gap: 10px;
  padding-block: clamp(20px, 3vw, 30px);
  border-bottom: 1px solid var(--line);
}
.contact-item {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 16px;
}
.contact-item__k {
  flex: 0 0 auto;
  min-width: 52px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--cyan);
}
.contact-item__v {
  font-size: 14px;
  color: rgba(244, 247, 251, 0.82);
  word-break: break-word;
}

.copy-btn {
  flex: 0 0 auto;
  padding: 4px 12px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--cyan-soft);
  transition: background-color 180ms ease-out, color 180ms ease-out, border-color 180ms ease-out;
}
.copy-btn:hover { background: rgba(43, 224, 214, 0.16); color: var(--paper); }

.footer-note {
  padding-top: clamp(18px, 2.4vw, 26px);
  font-size: 13px;
  color: var(--index);
}

.legal-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  justify-content: space-between;
  margin-top: clamp(20px, 3vw, 32px);
  padding-top: 18px;
  border-top: 1px solid var(--line);
}
.legal-bar__text {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--index);
}

.to-top {
  position: fixed;
  right: clamp(14px, 3vw, 28px);
  bottom: clamp(14px, 3vw, 28px);
  z-index: 80;
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-pill);
  background: rgba(22, 34, 74, 0.94);
  color: var(--cyan);
  font-size: 18px;
  line-height: 1;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 200ms ease-out, transform 200ms ease-out, visibility 200ms ease-out, background-color 200ms ease-out, color 200ms ease-out;
}
.to-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: none;
}
.to-top:hover { background: var(--cyan); color: #04121A; }

/* --------------------------- 17. 响应式断点 ---------------------------- */
@media (max-width: 1119px) {
  .nav-toggle { display: inline-flex; }

  .site-nav {
    display: none;
    position: absolute;
    top: calc(100% + 10px);
    left: 0;
    right: 0;
    z-index: 95;
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
    margin-left: 0;
    padding: 14px;
    border: 1px solid var(--line-strong);
    border-radius: 26px;
    background: rgba(14, 23, 48, 0.97);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    box-shadow: var(--shadow-float);
  }
  .site-nav[data-open] { display: flex; }

  .site-nav__list { flex-direction: column; align-items: stretch; gap: 4px; }
  .site-nav__item { display: block; }
  .site-nav__link {
    justify-content: flex-start;
    height: 44px;
    padding: 0 16px;
    font-size: 15px;
    border-radius: var(--radius-sm);
  }
  .site-nav__link[aria-current="page"] { border-radius: var(--radius-sm); }

  .site-nav__actions {
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    margin: 0;
    padding: 12px 0 0;
    border-left: 0;
    border-top: 1px solid var(--line);
  }
  .pill { height: 44px; justify-content: center; }

  .brand-text__line { display: none; }

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

@media (max-width: 900px) {
  .col-3, .col-4, .col-6, .col-8, .col-9 { grid-column: span 12; }
  .toc { position: static; }
  .axis { padding-left: 28px; }
  .axis__marker { left: -28px; width: 14px; height: 14px; }
  .axis::before { left: 6px; }
}

@media (max-width: 560px) {
  .site-header { padding: 10px 10px 0; }
  .header-shell { padding: 6px 6px 6px 12px; }
  .brand-text__name { font-size: 16px; }
  .footer-index { grid-template-columns: 1fr; }
  .legal-bar { flex-direction: column; }
  .contact-item { align-items: flex-start; }
  .to-top { width: 42px; height: 42px; }
}

/* ------------------------- 18. 减少动态效果 ---------------------------- */
@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;
    scroll-behavior: auto !important;
  }

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

  .axis__marker { box-shadow: none; }
}