/* ==========================================================================
   博业体育赛事 · 共享外壳样式 /assets/site.css
   深海蓝单色体系 + 竞技橙强调 + 等宽数据字体
   ========================================================================== */

:root {
  /* 色阶 */
  --ink-0: #061726;
  --ink-1: #0B2136;
  --ink-2: #16395C;
  --ink-3: #1C2733;
  --muted: #6E8296;
  --fg: #EEF3F8;
  --accent: #FF6A1A;
  --accent-2: #FF9A57;
  --signal: #B8FF4A;

  --line: rgba(238, 243, 248, .10);
  --line-strong: rgba(238, 243, 248, .20);
  --glass: rgba(22, 57, 92, .42);

  /* 字体 */
  --font-head: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  /* 尺度 */
  --wrap: 1400px;
  --gutter: clamp(1.1rem, 4vw, 3rem);
  --header-h: 72px;
  --radius: 4px;
  --ease: cubic-bezier(.2, .7, .2, 1);
}

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

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

body {
  margin: 0;
  background-color: var(--ink-0);
  background-image:
    radial-gradient(1100px 620px at 82% -8%, rgba(22, 57, 92, .55), transparent 62%),
    radial-gradient(760px 420px at 4% 14%, rgba(11, 33, 54, .85), transparent 68%);
  background-repeat: no-repeat;
  color: var(--fg);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  font-weight: 400;
  letter-spacing: .002em;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 900;
  line-height: 1.12;
  letter-spacing: -.02em;
  color: var(--fg);
}

p { margin: 0; }

ul, ol { margin: 0; padding: 0; }

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

button { font: inherit; color: inherit; }

a { color: inherit; }

hr { border: 0; border-top: 1px solid var(--line); margin: 0; }

table { border-collapse: collapse; width: 100%; }

/* ----------------------------------------------------------- 焦点与选择 -- */
:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 3px;
  border-radius: 2px;
}

::selection { background: var(--accent); color: var(--ink-0); }

/* ------------------------------------------------------------ 跳转链接 -- */
.skip-link {
  position: absolute;
  left: max(1rem, 3vw);
  top: -4rem;
  z-index: 200;
  padding: .6rem 1.05rem;
  background: var(--accent);
  color: var(--ink-0);
  font-weight: 800;
  font-size: .9rem;
  text-decoration: none;
  border-radius: 3px;
  transition: top .2s var(--ease);
}

.skip-link:focus { top: .8rem; }

/* =========================================================== 通用布局 == */
.container {
  width: min(var(--wrap), 100% - var(--gutter) * 2);
  margin-inline: auto;
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(.9rem, 2.4vw, 2rem);
}

.col-main { grid-column: span 7; }
.col-aside { grid-column: span 4; }
.col-ruler { grid-column: span 1; }
.col-full { grid-column: 1 / -1; }

/* ============================================================== 章节 == */
.chapter {
  position: relative;
  padding-block: clamp(3.25rem, 8vw, 7rem);
}

.chapter-band {
  display: block;
  width: clamp(88px, 16vw, 220px);
  height: 8px;
  border-radius: 2px;
  background-image: linear-gradient(90deg, var(--accent) 0%, rgba(255, 154, 87, .5) 45%, rgba(6, 23, 38, 0) 100%);
}

.chapter-head {
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
  gap: clamp(1rem, 4vw, 3.5rem);
  align-items: end;
  margin-block: clamp(1.5rem, 3.5vw, 2.6rem) clamp(1.6rem, 4vw, 3rem);
}

.chapter-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: .7rem;
}

.chapter-title {
  font-size: clamp(28px, 5.4vw, 62px);
  font-weight: 900;
  letter-spacing: -.02em;
}

.chapter-desc {
  font-size: clamp(.95rem, .5vw + .82rem, 1.05rem);
  line-height: 1.8;
  color: rgba(238, 243, 248, .74);
  max-width: 46ch;
}

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--muted);
}

.lead {
  font-size: clamp(1.02rem, .8vw + .85rem, 1.32rem);
  line-height: 1.7;
  color: rgba(238, 243, 248, .84);
  max-width: 40ch;
}

/* ============================================================== 文本 == */
.prose {
  max-width: 68ch;
  font-size: clamp(1rem, .3vw + .94rem, 1.12rem);
  line-height: 1.78;
  color: rgba(238, 243, 248, .86);
}

.prose > * + * { margin-top: 1.05em; }

.prose h2 { font-size: clamp(1.5rem, 3vw, 2.1rem); }
.prose h3 { font-size: clamp(1.15rem, 2vw, 1.42rem); font-weight: 800; letter-spacing: -.01em; }

.prose a {
  color: var(--accent-2);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 154, 87, .45);
}

.prose a:hover { color: var(--fg); border-bottom-color: var(--fg); }

.prose ul, .prose ol { padding-left: 1.15em; }
.prose li + li { margin-top: .45em; }
.prose li::marker { color: var(--accent); }
.prose strong { color: var(--fg); font-weight: 800; }

.mono, .data-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .01em;
}

.data-num {
  font-size: clamp(28px, 5vw, 56px);
  font-weight: 700;
  color: var(--fg);
  line-height: 1.05;
}

/* ============================================================ 面包屑 == */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .35rem;
  margin-bottom: clamp(1.2rem, 3vw, 2rem);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
}

.crumb { display: inline-flex; align-items: center; }

.crumb a {
  color: rgba(238, 243, 248, .74);
  text-decoration: none;
  padding-bottom: 1px;
  border-bottom: 1px solid transparent;
}

.crumb a:hover { color: var(--accent-2); border-bottom-color: rgba(255, 106, 26, .55); }

.crumb + .crumb::before {
  content: "/";
  margin-right: .45rem;
  color: rgba(238, 243, 248, .28);
}

.crumb[aria-current="page"] { color: var(--fg); }

/* ============================================================== 按钮 == */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  padding: .78rem 1.35rem;
  border: 1px solid transparent;
  border-radius: 3px;
  font-family: var(--font-head);
  font-size: .95rem;
  font-weight: 800;
  letter-spacing: .01em;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition: background-color .22s var(--ease), border-color .22s var(--ease), color .22s var(--ease), transform .22s var(--ease);
}

.btn--primary {
  background: var(--accent);
  color: var(--ink-0);
}

.btn--primary:hover { background: var(--accent-2); }
.btn--primary:active { transform: translateY(1px); }

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

.btn--ghost:hover { border-color: var(--accent); color: var(--accent-2); }

.btn--sm { padding: .5rem .9rem; font-size: .85rem; }

.btn[disabled], .btn[aria-disabled="true"] { opacity: .45; pointer-events: none; }

/* =========================================================== 标签 == */
.tag {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  padding: .22rem .55rem;
  border: 1px solid var(--line-strong);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--muted);
  white-space: nowrap;
}

.tag--accent {
  color: var(--accent-2);
  border-color: rgba(255, 106, 26, .42);
  background: rgba(255, 106, 26, .08);
}

.status-dot {
  display: inline-block;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--signal);
  flex: 0 0 auto;
}

.status-dot--pulse { animation: dot-pulse 2.4s ease-in-out infinite; }

@keyframes dot-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: .3; }
}

/* ============================================================== 卡片 == */
.card {
  position: relative;
  padding: clamp(1.1rem, 2.4vw, 1.8rem);
  border-radius: var(--radius);
  border: 1px solid var(--line);
  color: rgba(238, 243, 248, .84);
}

.card--solid {
  background: var(--ink-1);
  border-color: rgba(28, 39, 51, .9);
  box-shadow: 0 18px 42px -30px rgba(0, 0, 0, .9);
}

.card--glass {
  background: var(--glass);
  border-color: rgba(238, 243, 248, .14);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  backdrop-filter: blur(16px) saturate(140%);
}

.card-title {
  font-family: var(--font-head);
  font-size: clamp(1.05rem, 1.6vw, 1.32rem);
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--fg);
}

.card-meta {
  margin-top: .5rem;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted);
}

/* ============================================================== 数据 == */
.stat {
  display: flex;
  flex-direction: column;
  gap: .3rem;
  padding-block: .4rem;
}

.stat-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(28px, 5vw, 56px);
  font-weight: 700;
  line-height: 1;
  color: var(--accent);
}

.stat-label {
  font-size: .85rem;
  letter-spacing: .04em;
  color: var(--muted);
}

/* ========================================================== 筛选标签 == */
.filter-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: .45rem;
  align-items: center;
}

.filter-tab {
  padding: .42rem .85rem;
  background: transparent;
  border: 1px solid var(--line-strong);
  border-radius: 2px;
  color: rgba(238, 243, 248, .76);
  font-size: .85rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color .22s var(--ease), border-color .22s var(--ease), color .22s var(--ease);
}

.filter-tab:hover { border-color: var(--accent); color: var(--fg); }

.filter-tab[aria-selected="true"] {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--ink-0);
  font-weight: 800;
}

/* ========================================================== 折叠面板 == */
.accordion {
  border-top: 1px solid var(--line);
}

.accordion-item { border-bottom: 1px solid var(--line); }

.acc-trigger {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  width: 100%;
  padding: clamp(.95rem, 2vw, 1.35rem) 0;
  background: transparent;
  border: 0;
  cursor: pointer;
  text-align: left;
  font-family: var(--font-head);
  font-size: clamp(1rem, 1.4vw, 1.16rem);
  font-weight: 800;
  letter-spacing: -.005em;
  color: rgba(238, 243, 248, .82);
  transition: color .22s var(--ease);
}

.acc-trigger:hover { color: var(--fg); }

.acc-trigger[aria-expanded="true"] { color: var(--fg); }

.acc-icon {
  flex: 0 0 auto;
  width: 18px;
  height: 18px;
  margin-top: .35rem;
  position: relative;
}

.acc-icon::before,
.acc-icon::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  background: var(--accent);
  transform: translate(-50%, -50%);
  transition: transform .26s var(--ease), opacity .26s var(--ease);
}

.acc-icon::before { width: 14px; height: 2px; }
.acc-icon::after { width: 2px; height: 14px; }

.acc-trigger[aria-expanded="true"] .acc-icon::after { transform: translate(-50%, -50%) scaleY(0); opacity: 0; }

.acc-panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows .3s var(--ease);
}

.acc-panel[data-open] { grid-template-rows: 1fr; }

.acc-panel-inner {
  overflow: hidden;
  font-size: .96rem;
  line-height: 1.78;
  color: rgba(238, 243, 248, .78);
  max-width: 68ch;
}

.acc-panel[data-open] .acc-panel-inner { padding-bottom: clamp(1rem, 2vw, 1.4rem); }

/* ========================================================== 复制按钮 == */
.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .3rem .6rem;
  background: transparent;
  border: 1px solid var(--line-strong);
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted);
  cursor: pointer;
  transition: border-color .22s var(--ease), color .22s var(--ease), background-color .22s var(--ease);
}

.copy-btn:hover { border-color: var(--accent); color: var(--fg); }

.copy-btn.is-copied {
  border-color: var(--signal);
  color: var(--signal);
  background: rgba(184, 255, 74, .08);
}

/* ========================================================== 图片容器 == */
.media-frame {
  position: relative;
  overflow: hidden;
  margin: 0;
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--ink-1);
  background-image: linear-gradient(152deg, var(--ink-2) 0%, var(--ink-0) 78%);
}

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

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }

.media-frame--diagonal::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: linear-gradient(118deg, rgba(255, 106, 26, .22) 0%, rgba(255, 106, 26, .05) 38%, rgba(6, 23, 38, 0) 62%);
}

.media-frame[data-placeholder]::before {
  content: attr(data-placeholder);
  position: absolute;
  inset: auto 0 0 0;
  padding: .85rem 1rem;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: rgba(238, 243, 248, .58);
  background: linear-gradient(0deg, rgba(6, 23, 38, .9), rgba(6, 23, 38, 0));
}

.media-caption {
  margin-top: .7rem;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  line-height: 1.6;
  color: var(--muted);
}

/* ========================================================== 页面刻度尺 == */
.in-page-ruler {
  position: sticky;
  top: calc(var(--header-h) + 1.6rem);
  display: grid;
  gap: .85rem;
  padding-top: .3rem;
}

.ruler-item {
  display: grid;
  grid-template-columns: 2.2ch minmax(0, 1fr);
  align-items: center;
  gap: .55rem;
  text-decoration: none;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--muted);
  transition: color .24s var(--ease);
}

.ruler-num { line-height: 1; }

.ruler-bar {
  display: block;
  height: 2px;
  background: currentColor;
  opacity: .35;
  transition: opacity .24s var(--ease), transform .24s var(--ease);
  transform-origin: left center;
}

.ruler-item:hover { color: rgba(238, 243, 248, .9); }

.ruler-item.is-current { color: var(--accent); }
.ruler-item.is-current .ruler-bar { opacity: 1; transform: scaleX(1.15); }

/* ============================================================== 显现 == */
.js-reveal [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
}

.js-reveal [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

[data-reveal] {
  transition:
    opacity .42s cubic-bezier(.2, .7, .2, 1),
    transform .42s cubic-bezier(.2, .7, .2, 1);
}

/* ============================================================== 头部 == */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background: rgba(6, 23, 38, .88);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  backdrop-filter: blur(16px) saturate(140%);
  border-bottom: 1px solid var(--line);
  color: var(--fg);
  transition: background-color .28s var(--ease), border-color .28s var(--ease);
}

.site-header.is-scrolled {
  background: rgba(6, 23, 38, .97);
  border-bottom-color: var(--line-strong);
}

.header-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  overflow: hidden;
  pointer-events: none;
}

.header-progress-bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: left center;
  background-image: linear-gradient(90deg, var(--accent) 0%, var(--accent-2) 100%);
}

.header-inner {
  width: min(var(--wrap), 100% - var(--gutter) * 2);
  margin-inline: auto;
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  gap: clamp(.75rem, 2.5vw, 2.5rem);
  padding-block: .6rem;
}

/* 品牌 */
.brand {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: .7rem;
  text-decoration: none;
  color: inherit;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: .42rem .5rem;
  border: 1px solid rgba(255, 106, 26, .5);
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .12em;
  color: var(--accent);
  background: rgba(255, 106, 26, .07);
}

.brand-text { display: block; }

.brand-name {
  display: block;
  font-family: var(--font-head);
  font-size: 1.04rem;
  font-weight: 900;
  letter-spacing: -.01em;
  line-height: 1.25;
  color: var(--fg);
}

.brand-tag {
  display: block;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--muted);
  line-height: 1.4;
}

/* 主导航 */
.nav-primary {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: clamp(.5rem, 1.8vw, 1.6rem);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(.3rem, 1.2vw, 1rem);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-item { display: block; }

.nav-link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: .38rem;
  padding: .55rem .25rem;
  font-size: .93rem;
  font-weight: 500;
  color: rgba(238, 243, 248, .74);
  text-decoration: none;
  white-space: nowrap;
  transition: color .22s var(--ease);
}

.nav-index {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .08em;
  color: var(--muted);
  transition: color .22s var(--ease);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .26s var(--ease);
}

.nav-link:hover { color: var(--fg); }
.nav-link:hover::after { transform: scaleX(1); }

.nav-link[aria-current="page"] {
  color: var(--fg);
  font-weight: 900;
}

.nav-link[aria-current="page"]::after { transform: scaleX(1); }
.nav-link[aria-current="page"] .nav-index { color: var(--accent); }

/* 右上角短入口 */
.nav-utility {
  display: flex;
  align-items: center;
  gap: .5rem;
  padding-left: clamp(.5rem, 1.6vw, 1.4rem);
  border-left: 1px solid var(--line-strong);
}

.util-link {
  display: inline-block;
  padding: .42rem .72rem;
  border: 1px solid var(--line-strong);
  border-radius: 3px;
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .02em;
  color: rgba(238, 243, 248, .82);
  text-decoration: none;
  white-space: nowrap;
  transition: border-color .22s var(--ease), color .22s var(--ease), background-color .22s var(--ease);
}

.util-link:hover { border-color: var(--accent); color: var(--fg); }

.util-link--accent {
  border-color: rgba(255, 106, 26, .55);
  color: var(--accent-2);
  background: rgba(255, 106, 26, .08);
}

.util-link--accent:hover { background: rgba(255, 106, 26, .16); color: var(--accent-2); }

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  margin-left: auto;
  align-items: center;
  gap: .55rem;
  padding: .5rem .75rem;
  background: transparent;
  border: 1px solid var(--line-strong);
  border-radius: 3px;
  color: var(--fg);
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  cursor: pointer;
}

.nav-toggle-box {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  width: 16px;
  height: 12px;
}

.nav-toggle-bar {
  display: block;
  height: 2px;
  width: 100%;
  background: currentColor;
  transition: transform .26s var(--ease), opacity .26s var(--ease);
}

.site-header[data-open] .nav-toggle-bar:nth-child(1) { transform: translateY(3px) rotate(45deg); }
.site-header[data-open] .nav-toggle-bar:nth-child(2) { transform: translateY(-3px) rotate(-45deg); }

/* ============================================================== 页脚 == */
.site-footer {
  position: relative;
  margin-top: clamp(4rem, 10vw, 8rem);
  background: var(--ink-0);
  border-top: 1px solid var(--line);
  color: rgba(238, 243, 248, .72);
}

.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: min(360px, 52vw);
  height: 8px;
  background-image: linear-gradient(90deg, var(--accent) 0%, rgba(6, 23, 38, 0) 100%);
}

.footer-inner {
  width: min(var(--wrap), 100% - var(--gutter) * 2);
  margin-inline: auto;
  padding-block: clamp(2.6rem, 6vw, 4.5rem) 1.4rem;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 2fr);
  gap: clamp(1.8rem, 5vw, 4rem);
  align-items: start;
}

.footer-brand { max-width: 34ch; }

.footer-mark {
  display: block;
  font-family: var(--font-head);
  font-size: clamp(1.5rem, 3.4vw, 2.3rem);
  font-weight: 900;
  letter-spacing: -.02em;
  line-height: 1.1;
  color: var(--fg);
}

.footer-brand-line {
  margin-top: .55rem;
  font-size: .95rem;
  color: var(--accent-2);
  letter-spacing: .01em;
}

.footer-note {
  margin-top: .8rem;
  font-size: .82rem;
  line-height: 1.75;
  color: var(--muted);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(1.2rem, 3vw, 2.4rem);
}

.footer-col-title {
  margin: 0 0 .85rem;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--muted);
}

.footer-links {
  list-style: none;
  display: grid;
  gap: .5rem;
  margin: 0;
  padding: 0;
}

.footer-links a {
  display: inline-block;
  font-size: .92rem;
  color: rgba(238, 243, 248, .78);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
  transition: color .22s var(--ease), border-color .22s var(--ease);
}

.footer-links a:hover {
  color: var(--accent-2);
  border-bottom-color: rgba(255, 106, 26, .5);
}

.footer-contact {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem 1.8rem;
  margin-top: clamp(2rem, 5vw, 3rem);
  padding-top: 1.35rem;
  border-top: 1px solid var(--line);
  font-size: .88rem;
  line-height: 1.9;
  color: rgba(238, 243, 248, .74);
}

.footer-contact b {
  color: var(--muted);
  font-weight: 500;
  margin-right: .45rem;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .12em;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .5rem 1.6rem;
  margin-top: 1.3rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(238, 243, 248, .06);
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .04em;
  color: var(--muted);
}

.footer-copy, .footer-icp { margin: 0; }

/* ============================================================ 响应式 == */
@media (max-width: 1180px) {
  .nav-link { font-size: .88rem; }
  .nav-index { display: none; }
}

@media (max-width: 1023px) {
  .nav-toggle { display: inline-flex; }

  .nav-primary {
    position: fixed;
    top: var(--header-h);
    right: 0;
    bottom: 0;
    left: auto;
    width: min(360px, 88vw);
    margin-left: 0;
    padding: 1.35rem clamp(1.1rem, 4vw, 1.8rem) 2rem;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--ink-1);
    border-left: 1px solid var(--line);
    box-shadow: -30px 0 60px -40px rgba(0, 0, 0, .95);
    overflow-y: auto;
    transform: translateX(101%);
    transition: transform .3s var(--ease);
    z-index: 95;
  }

  .site-header[data-open] .nav-primary { transform: translateX(0); }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .nav-link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: .95rem .2rem;
    font-size: 1.02rem;
    border-bottom: 1px solid var(--line);
    white-space: normal;
  }

  .nav-index { display: inline; font-size: 11px; }

  .nav-link::after { display: none; }

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

  .nav-utility {
    flex-wrap: wrap;
    padding: 1.2rem .2rem 0;
    margin-top: auto;
    border-left: 0;
    border-top: 1px solid var(--line-strong);
  }

  .chapter-head { grid-template-columns: minmax(0, 1fr); align-items: start; }
  .chapter-desc { max-width: none; }

  .in-page-ruler { display: none; }
}

@media (max-width: 900px) {
  .col-main, .col-aside, .col-ruler { grid-column: 1 / -1; }

  .footer-top { grid-template-columns: minmax(0, 1fr); }
  .footer-brand { max-width: none; }
}

@media (max-width: 620px) {
  body { font-size: 16px; }

  .brand-tag { display: none; }
  .nav-toggle-text { display: none; }

  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.4rem 1rem; }
  .footer-contact { flex-direction: column; gap: .4rem; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }

  .btn { width: 100%; }
  .btn--sm { width: auto; }
}

/* ==================================================== 动效偏好兼容 == */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }

  .js-reveal [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .status-dot--pulse {
    animation: none;
    opacity: 1;
  }

  .header-progress-bar { transition: none; }
}