/* ==========================================================================
   火博体育 · 共享站点套件 /assets/site.css
   赛场夜灯 × 技术蓝图：深炭黑底、坐标网格、侧轨索引
   ========================================================================== */

/* ---------- 1. 设计变量 ---------- */
:root {
  --ink: #0B0D10;
  --deep: #050607;
  --panel: #171A1F;
  --rock: #2A2E34;
  --flame: #FF5A1F;
  --lava: #D7261E;
  --silver: #A8B0B8;
  --cyan: #3DE0FF;
  --moss: #5B7A5A;
  --clay: #B86B4B;
  --cream: #F3EFE6;

  --text: #E4E1D9;
  --line: rgba(168, 176, 184, 0.16);
  --line-2: rgba(168, 176, 184, 0.34);
  --grid: rgba(168, 176, 184, 0.055);

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

  --rail: 154px;
  --bar: 64px;
  --wrap: 1240px;

  --r-xl: 32px;
  --r-lg: 22px;
  --r-md: 14px;
  --r-sm: 10px;
  --pill: 999px;

  --ease: cubic-bezier(0.2, 0.7, 0.3, 1);
  --shadow: 0 30px 70px -42px rgba(0, 0, 0, 0.9);
}

/* ---------- 2. reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  min-height: 100vh;
  background-color: var(--ink);
  background-image:
    repeating-linear-gradient(90deg, var(--grid) 0 1px, transparent 1px 96px),
    repeating-linear-gradient(0deg, var(--grid) 0 1px, transparent 1px 96px);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg, video { max-width: 100%; }
img { height: auto; }

button { font: inherit; color: inherit; }

a { color: inherit; }

ul, ol { margin: 0; }

[hidden] { display: none !important; }

/* ---------- 3. 中文排版基线 ---------- */
h1, h2, h3, h4 {
  margin: 0 0 0.5em;
  font-family: var(--sans);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
  color: var(--cream);
}

h1 { font-size: clamp(34px, 5.6vw, 64px); line-height: 1.04; }
h2 { font-size: clamp(25px, 3.4vw, 40px); }
h3 { font-size: clamp(20px, 2.2vw, 28px); }
h4 { font-size: clamp(17px, 1.6vw, 20px); }

p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

.tilt { display: inline-block; transform: skewX(-2deg); }

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

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

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

::selection {
  background: rgba(255, 90, 31, 0.35);
  color: var(--cream);
}

/* ---------- 4. 布局容器与分区 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: clamp(16px, 4vw, 48px);
}

.zone {
  padding-block: clamp(48px, 7vw, 96px);
}

.zone--cream {
  background: var(--cream);
  color: #1A1D21;
  border-radius: var(--r-xl);
}

.zone--cream h1,
.zone--cream h2,
.zone--cream h3,
.zone--cream h4 { color: #12151A; }

.zone--cream .eyebrow { color: #6B7079; }
.zone--cream .panel { background: #FFFFFF; border-color: rgba(11, 13, 16, 0.12); }
.zone--cream .stat__value { color: #12151A; }
.zone--cream .stat__label { color: #6B7079; }
.zone--cream .prose { color: #20242A; }

.rule {
  height: 1px;
  border: 0;
  margin: 0;
  background: var(--line);
}

.blueprint {
  position: relative;
  background-image:
    repeating-linear-gradient(90deg, var(--grid) 0 1px, transparent 1px 72px),
    repeating-linear-gradient(0deg, var(--grid) 0 1px, transparent 1px 72px);
}

/* ---------- 5. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: var(--pill);
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease),
    border-color 0.2s var(--ease), box-shadow 0.2s var(--ease),
    transform 0.2s var(--ease);
}

.btn--primary {
  background: var(--flame);
  color: #120804;
  border-color: var(--flame);
  box-shadow: 0 14px 34px -22px rgba(255, 90, 31, 0.9);
}

.btn--primary:hover,
.btn--primary:focus-visible {
  background: #FF7A45;
  border-color: #FF7A45;
  box-shadow: 0 0 0 4px rgba(255, 90, 31, 0.18);
}

.btn--ghost {
  background: transparent;
  color: var(--cream);
  border-color: var(--line-2);
}

.btn--ghost:hover,
.btn--ghost:focus-visible {
  border-color: var(--flame);
  color: var(--flame);
}

.btn--sm {
  min-height: 38px;
  padding: 0 16px;
  font-size: 13px;
}

.btn:active { transform: translateY(1px); }

/* ---------- 6. 胶囊标签 ---------- */
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 13px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  background: rgba(42, 46, 52, 0.55);
  color: var(--silver);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  line-height: 1.5;
  white-space: nowrap;
}

.chip--flame {
  color: var(--flame);
  border-color: rgba(255, 90, 31, 0.42);
  background: rgba(255, 90, 31, 0.1);
}

.chip--cyan {
  color: var(--cyan);
  border-color: rgba(61, 224, 255, 0.36);
  background: rgba(61, 224, 255, 0.08);
}

.chip--moss {
  color: #93B592;
  border-color: rgba(91, 122, 90, 0.55);
  background: rgba(91, 122, 90, 0.18);
}

.chip--clay {
  color: #DA9679;
  border-color: rgba(184, 107, 75, 0.48);
  background: rgba(184, 107, 75, 0.15);
}

/* ---------- 7. 索引小标 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 14px;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--silver);
}

.eyebrow::after {
  content: "";
  width: clamp(28px, 8vw, 64px);
  height: 1px;
  background: var(--line-2);
}

.eyebrow__num { color: var(--flame); }

/* ---------- 8. 面板与统计 ---------- */
.panel {
  position: relative;
  padding: clamp(20px, 3vw, 32px);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--panel);
  box-shadow: var(--shadow);
}

.panel--stat { overflow: hidden; }

.panel--stat::after {
  content: "";
  position: absolute;
  inset: 0 auto auto 0;
  width: 46%;
  height: 2px;
  background: linear-gradient(90deg, var(--flame), transparent);
}

.panel--cream {
  background: var(--cream);
  color: #16130F;
  border-color: rgba(0, 0, 0, 0.1);
}

.stat { display: grid; gap: 6px; }

.stat__value {
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(40px, 6vw, 72px);
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--cream);
}

.stat--accent .stat__value { color: var(--flame); }

.stat__label {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--silver);
}

.stat__hint {
  font-size: 13px;
  line-height: 1.7;
  color: rgba(168, 176, 184, 0.78);
}

/* ---------- 9. 面包屑 ---------- */
.breadcrumb { padding-block: 18px; }

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 13px;
  font-family: var(--mono);
  letter-spacing: 0.04em;
}

.breadcrumb__item { display: inline-flex; align-items: center; gap: 8px; }

.breadcrumb__item:not(:first-child)::before {
  content: "/";
  color: rgba(168, 176, 184, 0.45);
}

.breadcrumb__link {
  color: var(--silver);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.breadcrumb__link:hover,
.breadcrumb__link:focus-visible {
  color: var(--cyan);
  border-color: var(--cyan);
}

.breadcrumb__current { color: var(--cream); }

/* ---------- 10. 正文容器 ---------- */
.prose {
  max-width: 72ch;
  font-size: 17px;
  line-height: 1.85;
  color: var(--text);
}

.prose h2 { margin-top: 1.8em; }
.prose h3 { margin-top: 1.5em; }

.prose ul,
.prose ol { padding-left: 1.25em; margin: 0 0 1em; }
.prose li { margin-bottom: 0.4em; }

.prose a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(61, 224, 255, 0.4);
}

.prose a:hover,
.prose a:focus-visible { border-color: var(--cyan); }

.prose blockquote {
  margin: 1.6em 0;
  padding: 4px 0 4px 20px;
  border-left: 3px solid var(--flame);
  color: var(--silver);
}

.prose code {
  font-family: var(--mono);
  font-size: 0.92em;
  padding: 0.1em 0.4em;
  border-radius: var(--r-sm);
  background: rgba(42, 46, 52, 0.7);
  color: var(--cyan);
}

/* ---------- 11. 图片容器基础规则 ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 4 / 3;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background:
    repeating-linear-gradient(135deg, rgba(168, 176, 184, 0.06) 0 1px, transparent 1px 14px),
    linear-gradient(150deg, #1B1F25, #10141A 70%);
}

.media > img,
.media > picture > img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media--wide { aspect-ratio: 16 / 9; }
.media--tall { aspect-ratio: 3 / 4; }
.media--square { aspect-ratio: 1 / 1; }

.media--glow {
  box-shadow:
    0 0 0 1px rgba(61, 224, 255, 0.2),
    0 26px 70px -38px rgba(255, 90, 31, 0.62);
}

/* ---------- 12. 标签页 ---------- */
.tabs { display: grid; gap: 22px; }

.tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tabs__tab {
  appearance: none;
  min-height: 40px;
  padding: 0 18px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  background: rgba(42, 46, 52, 0.5);
  color: var(--silver);
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease),
    border-color 0.2s var(--ease);
}

.tabs__tab:hover {
  color: var(--cream);
  border-color: var(--line-2);
}

.tabs__tab[aria-selected="true"] {
  background: var(--flame);
  border-color: var(--flame);
  color: #120804;
}

.tabs__panel { animation: hb-fade 0.22s var(--ease) both; }

@keyframes hb-fade {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 13. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 12px;
  z-index: 200;
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  padding: 0 18px;
  border-radius: var(--pill);
  background: var(--cream);
  color: var(--ink);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  transform: translateY(-160%);
  transition: transform 0.2s var(--ease);
}

.skip-link:focus-visible { transform: translateY(0); }

/* ---------- 14. 页头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
}

.header-strip {
  display: flex;
  align-items: center;
  gap: clamp(10px, 2vw, 28px);
  min-height: var(--bar);
  padding: 10px clamp(16px, 3vw, 36px);
  background: #0B0D10;
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  text-decoration: none;
  color: var(--cream);
}

.brand__mark {
  display: grid;
  place-items: center;
  flex: none;
  width: 38px;
  height: 38px;
  border-radius: 12px;
  background: linear-gradient(150deg, var(--flame), var(--lava));
  color: #12060A;
  font-size: 19px;
  font-weight: 800;
  line-height: 1;
  box-shadow: 0 10px 26px -16px rgba(255, 90, 31, 0.95);
  transition: transform 0.22s var(--ease);
}

.brand:hover .brand__mark,
.brand:focus-visible .brand__mark { transform: rotate(-6deg); }

.brand__text { display: grid; gap: 1px; min-width: 0; }

.brand__name {
  font-size: 17px;
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.2;
}

.brand__line {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  color: rgba(168, 176, 184, 0.86);
  white-space: nowrap;
}

.header-note {
  display: none;
  align-items: center;
  gap: 8px;
  margin: 0 auto 0 8px;
  font-size: 13px;
  line-height: 1.5;
  color: rgba(168, 176, 184, 0.85);
}

.header-note::before {
  content: "";
  flex: none;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(61, 224, 255, 0.16);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-left: auto;
}

.header-cta { display: none; }

/* 汉堡按钮 */
.nav-toggle {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0 11px;
  border: 1px solid var(--line-2);
  border-radius: var(--r-md);
  background: transparent;
  cursor: pointer;
  transition: border-color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.nav-toggle:hover { border-color: var(--flame); }

.nav-toggle__bar {
  display: block;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: var(--cream);
  transition: transform 0.22s var(--ease), opacity 0.18s var(--ease),
    width 0.22s var(--ease);
}

.nav-toggle__bar:nth-child(2) { width: 68%; }

.site-header[data-open] .nav-toggle__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.site-header[data-open] .nav-toggle__bar:nth-child(2) {
  opacity: 0;
  width: 0;
}

.site-header[data-open] .nav-toggle__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* 遮罩 */
.nav-scrim {
  position: fixed;
  inset: 0;
  z-index: 94;
  background: rgba(5, 6, 7, 0.7);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.24s var(--ease);
}

.site-header[data-open] .nav-scrim {
  opacity: 1;
  pointer-events: auto;
}

/* 导航本体 —— 移动端抽屉 */
.site-nav {
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  z-index: 95;
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: min(320px, 86vw);
  padding: 18px 16px 26px;
  overflow-y: auto;
  background: #0E1116;
  border-right: 1px solid var(--line-2);
  transform: translateX(-102%);
  transition: transform 0.24s var(--ease);
}

.site-header[data-open] .site-nav {
  transform: none;
  box-shadow: 0 0 80px rgba(0, 0, 0, 0.75);
}

.nav-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 14px;
  margin-bottom: 6px;
  border-bottom: 1px solid var(--line);
}

.nav-head__label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: rgba(168, 176, 184, 0.72);
}

.nav-close {
  position: relative;
  flex: none;
  width: 40px;
  height: 40px;
  border: 1px solid var(--line-2);
  border-radius: var(--r-md);
  background: transparent;
  cursor: pointer;
  transition: border-color 0.2s var(--ease);
}

.nav-close:hover { border-color: var(--flame); }

.nav-close__bar {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: var(--cream);
}

.nav-close__bar:first-child { transform: translate(-50%, -50%) rotate(45deg); }
.nav-close__bar:last-child { transform: translate(-50%, -50%) rotate(-45deg); }

.nav-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-link {
  position: relative;
  display: flex;
  flex-direction: row;
  align-items: baseline;
  gap: 12px;
  padding: 13px 14px;
  border-radius: var(--r-md);
  text-decoration: none;
  color: var(--silver);
  transition: color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.nav-link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  bottom: 12px;
  width: 2px;
  border-radius: 2px;
  background: transparent;
  transition: background-color 0.2s var(--ease);
}

.nav-link__index {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  color: rgba(168, 176, 184, 0.55);
}

.nav-link__label {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 0.02em;
  line-height: 1.35;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--cream);
  background: rgba(255, 90, 31, 0.09);
}

.nav-link:hover::before,
.nav-link:focus-visible::before { background: var(--flame); }

.nav-link[aria-current="page"] {
  color: var(--cream);
  background: rgba(255, 90, 31, 0.15);
}

.nav-link[aria-current="page"]::before { background: var(--flame); }

.nav-link[aria-current="page"] .nav-link__index { color: var(--flame); }

.nav-drawer-cta {
  margin-top: 12px;
  width: 100%;
}

.rail-foot { display: none; }

/* ---------- 15. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(64px, 8vw, 120px);
  overflow: hidden;
  background-color: var(--deep);
  background-image:
    repeating-linear-gradient(90deg, rgba(168, 176, 184, 0.045) 0 1px, transparent 1px 96px),
    repeating-linear-gradient(0deg, rgba(168, 176, 184, 0.045) 0 1px, transparent 1px 96px);
  border-top: 1px solid var(--line-2);
  color: var(--silver);
}

.site-footer::before {
  content: "";
  position: absolute;
  left: -12%;
  top: -40%;
  width: 62%;
  height: 150%;
  background: radial-gradient(closest-side, rgba(255, 90, 31, 0.15), transparent);
  pointer-events: none;
}

.footer-top {
  position: relative;
  display: grid;
  gap: clamp(28px, 4vw, 56px);
  padding-top: clamp(48px, 7vw, 88px);
  padding-bottom: clamp(34px, 5vw, 62px);
}

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

.footer-wordmark {
  margin: 0 0 10px;
  font-size: clamp(36px, 6.6vw, 74px);
  font-weight: 800;
  letter-spacing: -0.035em;
  line-height: 1;
  color: var(--cream);
}

.footer-wordmark::after {
  content: "";
  display: inline-block;
  width: 0.16em;
  height: 0.16em;
  margin-left: 0.1em;
  border-radius: 50%;
  background: var(--flame);
  vertical-align: baseline;
}

.footer-tagline {
  margin: 0 0 16px;
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--flame);
}

.footer-note {
  max-width: 34em;
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: rgba(168, 176, 184, 0.82);
}

.footer-col__title {
  margin: 0 0 16px;
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  line-height: 1.4;
  color: rgba(168, 176, 184, 0.72);
}

.footer-list {
  display: grid;
  gap: 10px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-list__item { position: relative; }

.footer-link {
  display: inline-block;
  font-size: 14px;
  color: var(--silver);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.footer-link:hover,
.footer-link:focus-visible {
  color: var(--cream);
  border-color: var(--flame);
}

.footer-contact {
  display: grid;
  gap: 12px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-contact__row {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 10px;
  align-items: baseline;
  font-size: 14px;
  line-height: 1.7;
}

.footer-contact__label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: rgba(168, 176, 184, 0.6);
}

.footer-contact__value {
  color: var(--cream);
  overflow-wrap: anywhere;
}

.footer-bottom {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 24px;
  padding-top: 20px;
  padding-bottom: 28px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: rgba(168, 176, 184, 0.78);
}

.footer-copyright {
  margin: 0;
  font-family: var(--mono);
  letter-spacing: 0.06em;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-icp {
  margin: 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: rgba(168, 176, 184, 0.62);
}

.to-top {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 38px;
  margin-left: auto;
  padding: 0 18px;
  border: 1px solid var(--line-2);
  border-radius: var(--pill);
  background: transparent;
  color: var(--cream);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease),
    background-color 0.2s var(--ease);
}

.to-top:hover,
.to-top:focus-visible {
  color: var(--flame);
  border-color: var(--flame);
  background: rgba(255, 90, 31, 0.08);
}

.to-top__arrow {
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1;
}

/* ---------- 16. 响应式 ---------- */
@media (min-width: 560px) {
  .header-cta { display: inline-flex; }
}

@media (min-width: 900px) {
  .header-note { display: flex; }
  .footer-top { grid-template-columns: 1.4fr 1fr 1.2fr; }
}

@media (min-width: 1024px) {
  body { padding-left: var(--rail); }

  .nav-toggle { display: none; }
  .nav-scrim { display: none; }
  .nav-drawer-cta { display: none; }

  .site-nav {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    width: var(--rail);
    transform: none;
    padding: calc(var(--bar) + 26px) 14px 22px;
    gap: 2px;
    overflow: visible;
    background: linear-gradient(180deg, #0B0D10 0%, #0E1117 55%, #0B0D10 100%);
    border-right: 1px solid var(--line);
    box-shadow: none;
  }

  .site-nav::before {
    content: "";
    position: absolute;
    left: 14px;
    right: 14px;
    top: calc(var(--bar) - 1px);
    height: 1px;
    background: var(--line-2);
  }

  .nav-head { display: none; }

  .nav-list { gap: 3px; }

  .nav-link {
    flex-direction: column;
    align-items: flex-start;
    gap: 1px;
    padding: 10px 12px 10px 14px;
    border-radius: var(--r-sm);
  }

  .nav-link::before { top: 10px; bottom: 10px; }

  .nav-link__label { font-size: 14px; font-weight: 600; }

  .rail-foot {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-top: auto;
    padding: 16px 12px 0;
    border-top: 1px solid var(--line);
  }

  .rail-foot__label {
    font-family: var(--mono);
    font-size: 9px;
    letter-spacing: 0.2em;
    color: rgba(168, 176, 184, 0.45);
  }

  .rail-foot__scale {
    display: flex;
    align-items: flex-end;
    gap: 5px;
    height: 20px;
  }

  .rail-foot__tick {
    display: block;
    width: 2px;
    border-radius: 2px;
    background: rgba(168, 176, 184, 0.3);
  }

  .rail-foot__tick:nth-child(1) { height: 6px; }
  .rail-foot__tick:nth-child(2) { height: 11px; background: var(--flame); }
  .rail-foot__tick:nth-child(3) { height: 8px; }
  .rail-foot__tick:nth-child(4) { height: 15px; background: rgba(61, 224, 255, 0.55); }
  .rail-foot__tick:nth-child(5) { height: 9px; }
  .rail-foot__tick:nth-child(6) { height: 13px; }
}

@media (max-width: 559px) {
  :root { --bar: 58px; }
  .brand__line { display: none; }
  .brand__mark { width: 34px; height: 34px; border-radius: 10px; font-size: 17px; }
  .brand__name { font-size: 16px; }
  .tabs__list {
    flex-wrap: nowrap;
    overflow-x: auto;
    padding-bottom: 4px;
    scrollbar-width: none;
  }
  .tabs__list::-webkit-scrollbar { display: none; }
  .to-top { margin-left: 0; }
}

@media (min-width: 768px) {
  .tabs__panel { padding-top: 2px; }
}

/* ---------- 17. 无障碍与动效偏好 ---------- */
@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;
  }
}