/* ==========================================================================
   完美体育看台 · /assets/site.css
   共享外壳：reset / 变量 / 中文排版 / 页头 / 页脚 / 通用组件
   母题：夜场看台 + 数据指挥中心
   ========================================================================== */

/* ---------- 01 reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

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

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

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

button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; padding: 0; }

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

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

#main-content { scroll-margin-top: 92px; }

/* ---------- 02 变量 ---------- */
:root {
  /* 色彩系统 */
  --c-void: #0B1B34;
  --c-void-deep: #071223;
  --c-void-raise: #0A1729;
  --c-steel: #132B4C;
  --c-line: #2C4A73;
  --c-cyan: #34E0D0;
  --c-amber: #FFA23A;
  --c-violet: #7B5BFF;
  --c-violet-soft: #A995FF;
  --c-ink: #E8EDF4;
  --c-mist: #9AA9BF;
  --c-wine: #6E1B38;
  --c-teal: #0E3B3A;
  --c-green: #5BE0A0;
  --c-ink-dark: #06121F;

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

  /* 结构 */
  --w: 1320px;
  --pad-x: clamp(1rem, 3vw, 2rem);
  --gap-y: clamp(2rem, 5vw, 3.5rem);
  --notch-lg: 24px;
  --notch-sm: 10px;

  /* 语义 */
  --z-header: 90;
  --z-skip: 200;
}

/* ---------- 03 基础排版 ---------- */
body {
  background-color: var(--c-void);
  color: var(--c-ink);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  letter-spacing: 0;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 斜向轨迹底纹：承载视线引导，不做纯装饰 */
body::before {
  content: "";
  position: fixed;
  inset: -10% -10% -10% -10%;
  z-index: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(115deg,
      rgba(44, 74, 115, 0.24) 0 1px,
      transparent 1px 96px);
  opacity: 0.55;
}

body > * { position: relative; z-index: 1; }

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 900;
  font-stretch: condensed;
  letter-spacing: -0.02em;
  line-height: 1.16;
  text-wrap: balance;
}

h2 { font-size: clamp(1.5rem, 3vw, 2rem); }
h3 { font-size: clamp(1.125rem, 2vw, 1.5rem); }
h4 { font-size: 1rem; }

p { text-wrap: pretty; }

::selection { background: var(--c-cyan); color: var(--c-ink-dark); }

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

.skip-link {
  position: fixed;
  top: 0;
  left: clamp(1rem, 3vw, 2rem);
  z-index: var(--z-skip);
  padding: 0.6rem 1.1rem;
  background: var(--c-cyan);
  color: var(--c-ink-dark);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  transform: translateY(-130%);
  transition: transform 0.18s ease;
  clip-path: polygon(0 0, 100% 0, 100% 100%, 12px 100%, 0 calc(100% - 12px));
}

.skip-link:focus-visible {
  transform: translateY(0);
  outline-offset: -4px;
}

/* ---------- 04 布局容器 ---------- */
.wrap {
  width: 100%;
  max-width: var(--w);
  margin: 0 auto;
  padding-left: var(--pad-x);
  padding-right: var(--pad-x);
}

.grid {
  display: grid;
  gap: clamp(1rem, 2.4vw, 1.75rem);
}

.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--split { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); }
.grid--split-rev { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); }

.prose {
  max-width: 72ch;
  font-size: clamp(1rem, 0.95rem + 0.2vw, 1.0625rem);
  color: var(--c-ink);
}

.prose > * + * { margin-top: 1.05em; }
.prose h2 { margin-top: 1.8em; }
.prose h3 { margin-top: 1.5em; }
.prose p { color: #DCE4EF; }
.prose ul, .prose ol { padding-left: 1.15em; }
.prose ul li { list-style: none; position: relative; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: -1.05em;
  top: 0.72em;
  width: 8px;
  height: 2px;
  background: var(--c-cyan);
}
.prose ol { list-style: decimal; }
.prose a {
  color: var(--c-cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}
.prose strong { color: #fff; font-weight: 700; }

/* ---------- 05 页头：紧凑命令栏 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  background: rgba(9, 22, 43, 0.94);
  border-bottom: 1px solid var(--c-line);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  transition: box-shadow 0.22s ease;
}

.site-header[data-shrink="true"] {
  box-shadow: 0 14px 34px rgba(3, 9, 20, 0.55);
}

.header-inner {
  width: 100%;
  max-width: var(--w);
  margin: 0 auto;
  padding: 0 var(--pad-x);
  min-height: 66px;
  display: flex;
  align-items: center;
  gap: clamp(0.6rem, 1.6vw, 1.25rem);
  transition: min-height 0.22s ease;
}

.site-header[data-shrink="true"] .header-inner { min-height: 56px; }

/* 品牌 */
.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  flex: 0 0 auto;
  padding: 0.5rem 0;
}

.brand__index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 26px;
  background: var(--c-cyan);
  color: var(--c-ink-dark);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  clip-path: polygon(0 0, 100% 0, 100% 62%, 76% 100%, 0 100%);
}

.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand__name {
  font-family: var(--font-head);
  font-weight: 900;
  font-stretch: condensed;
  font-size: 1.0625rem;
  letter-spacing: -0.01em;
  color: var(--c-ink);
}

.brand__sub {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.08em;
  color: var(--c-mist);
}

/* 移动端按钮 */
.nav-toggle {
  display: none;
  margin-left: auto;
  align-items: center;
  gap: 0.5rem;
  padding: 0.45rem 0.7rem;
  border: 1px solid var(--c-line);
  background: rgba(19, 43, 76, 0.6);
  color: var(--c-ink);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  cursor: pointer;
  clip-path: polygon(0 0, calc(100% - var(--notch-sm)) 0, 100% var(--notch-sm), 100% 100%, var(--notch-sm) 100%, 0 calc(100% - var(--notch-sm)));
}

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  width: 14px;
}

.nav-toggle__bars i {
  display: block;
  height: 2px;
  background: var(--c-cyan);
  transition: transform 0.18s ease, opacity 0.18s ease;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

/* 导航 */
.site-nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 0.1rem;
}

.nav-link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.36rem;
  padding: 0.5rem 0.58rem;
  font-size: 0.8125rem;
  line-height: 1.4;
  color: var(--c-mist);
  border-bottom: 2px solid transparent;
  transition: color 0.16s ease, background-color 0.16s ease, border-color 0.16s ease;
}

.nav-link__id {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.06em;
  color: var(--c-line);
  font-variant-numeric: tabular-nums;
  transition: color 0.16s ease;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--c-ink);
  background: rgba(52, 224, 208, 0.07);
}

.nav-link:hover .nav-link__id,
.nav-link:focus-visible .nav-link__id { color: var(--c-cyan); }

.nav-link[aria-current="page"] {
  color: var(--c-cyan);
  border-bottom-color: var(--c-cyan);
  background: rgba(52, 224, 208, 0.08);
}

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-left: 0.6rem;
}

.nav-actions .btn--ghost { display: none; }

/* command strip */
.header-strip {
  width: 100%;
  max-width: var(--w);
  margin: 0 auto;
  padding: 0 var(--pad-x) 0.5rem;
  display: flex;
  align-items: center;
  gap: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.05em;
  color: var(--c-mist);
  max-height: 34px;
  overflow: hidden;
  transition: max-height 0.22s ease, opacity 0.22s ease, padding-bottom 0.22s ease;
}

.header-strip__link {
  margin-right: auto;
  color: var(--c-cyan);
  border-bottom: 1px dashed rgba(52, 224, 208, 0.5);
}

.header-strip__link:hover,
.header-strip__link:focus-visible { border-bottom-style: solid; }

.header-strip__meta { white-space: nowrap; }

.site-header[data-shrink="true"] .header-strip {
  max-height: 0;
  opacity: 0;
  padding-bottom: 0;
}

/* 滚动进度 */
.scroll-meter {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  pointer-events: none;
}

.scroll-meter__bar {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--c-cyan) 0%, var(--c-violet) 70%, var(--c-amber) 100%);
}

/* ---------- 06 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.6rem 1.05rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.03em;
  line-height: 1.35;
  border: 1px solid transparent;
  cursor: pointer;
  text-align: center;
  clip-path: polygon(0 0, calc(100% - var(--notch-sm)) 0, 100% var(--notch-sm), 100% 100%, var(--notch-sm) 100%, 0 calc(100% - var(--notch-sm)));
  transition: background-color 0.16s ease, color 0.16s ease, border-color 0.16s ease, transform 0.16s ease;
}

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

.btn:focus-visible { outline-offset: -3px; outline-color: var(--c-ink); }

.btn--primary {
  background: var(--c-cyan);
  color: var(--c-ink-dark);
  font-weight: 700;
}

.btn--primary:hover,
.btn--primary:focus-visible { background: #5BECE0; }

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

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

.btn--amber {
  background: var(--c-amber);
  color: #241305;
  font-weight: 700;
}

.btn--sm { padding: 0.45rem 0.8rem; font-size: 0.75rem; }

/* ---------- 07 通用组件 ---------- */
.display {
  font-family: var(--font-head);
  font-weight: 900;
  font-stretch: condensed;
  font-size: clamp(2.6rem, 7vw, 5.4rem);
  line-height: 1.02;
  letter-spacing: -0.02em;
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-mist);
}

.section-label::before {
  content: "";
  width: 16px;
  height: 2px;
  background: var(--c-cyan);
  flex: 0 0 auto;
}

.panel {
  position: relative;
  background: var(--c-steel);
  box-shadow: inset 0 0 0 1px var(--c-line);
  padding: clamp(1.25rem, 2.6vw, 2rem);
  clip-path: polygon(
    0 0,
    calc(100% - var(--notch-lg)) 0,
    100% var(--notch-lg),
    100% 100%,
    var(--notch-lg) 100%,
    0 calc(100% - var(--notch-lg))
  );
}

.panel--tight { padding: clamp(1rem, 2vw, 1.35rem); }

.panel__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.6rem 0.9rem;
  padding-bottom: 0.85rem;
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--c-line);
}

.panel__id {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: var(--c-cyan);
  font-variant-numeric: tabular-nums;
}

.panel__title {
  font-family: var(--font-head);
  font-weight: 900;
  font-stretch: condensed;
  font-size: clamp(1.0625rem, 1.6vw, 1.3125rem);
  letter-spacing: -0.01em;
}

.panel__text { font-size: 0.9375rem; color: #CBD6E4; }

.panel__note {
  font-size: 0.8125rem;
  color: var(--c-mist);
  line-height: 1.7;
}

.zone {
  padding: clamp(1.5rem, 3vw, 2.5rem);
  box-shadow: inset 0 0 0 1px var(--c-line);
  clip-path: polygon(
    0 0,
    calc(100% - var(--notch-lg)) 0,
    100% var(--notch-lg),
    100% 100%,
    var(--notch-lg) 100%,
    0 calc(100% - var(--notch-lg))
  );
}

.zone--wine { background: var(--c-wine); }
.zone--teal { background: var(--c-teal); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.22rem 0.55rem;
  border: 1px solid var(--c-line);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-mist);
  font-variant-numeric: tabular-nums;
}

.tag--cyan { color: var(--c-cyan); border-color: rgba(52, 224, 208, 0.45); background: rgba(52, 224, 208, 0.08); }
.tag--amber { color: var(--c-amber); border-color: rgba(255, 162, 58, 0.45); background: rgba(255, 162, 58, 0.08); }
.tag--violet { color: var(--c-violet-soft); border-color: rgba(123, 91, 255, 0.5); background: rgba(123, 91, 255, 0.12); }
.tag--green { color: var(--c-green); border-color: rgba(91, 224, 160, 0.45); background: rgba(91, 224, 160, 0.08); }

.index-list { display: grid; }

.index-item {
  display: grid;
  grid-template-columns: 4.5rem minmax(0, 1fr) auto;
  gap: 0.5rem 1rem;
  align-items: baseline;
  padding: 0.8rem 0;
  border-bottom: 1px dashed rgba(44, 74, 115, 0.75);
}

.index-item__id {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--c-cyan);
  font-variant-numeric: tabular-nums;
}

.index-item__text { font-size: 0.9375rem; color: var(--c-ink); }

.index-item__meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--c-mist);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.kpi { display: flex; flex-direction: column; gap: 0.25rem; }

.kpi__value {
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 3.4vw, 2.4rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--c-cyan);
  font-variant-numeric: tabular-nums;
}

.kpi__label {
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  color: var(--c-mist);
}

.kpi--amber .kpi__value { color: var(--c-amber); }
.kpi--violet .kpi__value { color: var(--c-violet-soft); }

.data-table { font-size: 0.9375rem; }

.data-table caption {
  text-align: left;
  padding-bottom: 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--c-mist);
}

.data-table th,
.data-table td {
  padding: 0.6rem 0.75rem;
  border-bottom: 1px solid rgba(44, 74, 115, 0.55);
  text-align: left;
  vertical-align: baseline;
}

.data-table th {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-mist);
  white-space: nowrap;
}

.data-table td.num {
  font-family: var(--font-mono);
  color: var(--c-cyan);
  font-variant-numeric: tabular-nums;
}

.data-table tbody tr:hover { background: rgba(52, 224, 208, 0.05); }

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem;
  padding: 0.9rem 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  color: var(--c-mist);
}

.breadcrumbs a:hover,
.breadcrumbs a:focus-visible { color: var(--c-cyan); }
.breadcrumbs__sep { color: var(--c-line); }

.slash-rule {
  height: 1px;
  border: 0;
  margin: clamp(2rem, 5vw, 3.5rem) 0;
  background: linear-gradient(90deg, var(--c-cyan) 0%, rgba(44, 74, 115, 0.9) 45%, transparent 100%);
  opacity: 0.7;
}

.slash-divider {
  height: 2px;
  margin: clamp(2rem, 5vw, 3.5rem) 0;
  transform: skewY(-1.2deg);
  background: linear-gradient(90deg, transparent 0%, var(--c-line) 16%, var(--c-cyan) 50%, var(--c-line) 84%, transparent 100%);
  opacity: 0.8;
}

/* 图像容器：页面阶段放图用 */
.media-frame {
  position: relative;
  overflow: hidden;
  background-color: var(--c-steel);
  background-image:
    linear-gradient(135deg, rgba(52, 224, 208, 0.08), rgba(123, 91, 255, 0.08)),
    repeating-linear-gradient(115deg, rgba(44, 74, 115, 0.55) 0 1px, transparent 1px 24px);
  box-shadow: inset 0 0 0 1px var(--c-line);
  aspect-ratio: 16 / 9;
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--cinema { aspect-ratio: 2.35 / 1; }

.media-frame__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.92) contrast(1.06) brightness(0.94);
}

.media-frame__label {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 0.4rem 0.7rem;
  background: rgba(7, 18, 35, 0.86);
  border-top: 1px solid var(--c-line);
  border-right: 1px solid var(--c-line);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  color: var(--c-cyan);
  font-variant-numeric: tabular-nums;
}

/* 滚动显现 */
.reveal { transition: opacity 0.55s ease, transform 0.55s ease; }

html.js-motion .reveal:not(.is-visible) {
  opacity: 0;
  transform: translateY(14px);
}

/* ---------- 08 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(4rem, 9vw, 8rem);
  background: linear-gradient(180deg, var(--c-void-raise) 0%, var(--c-void-deep) 100%);
  border-top: 1px solid var(--c-line);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: min(48%, 540px);
  height: 180px;
  pointer-events: none;
  background: linear-gradient(115deg, rgba(52, 224, 208, 0.11), transparent 72%);
}

.footer-inner {
  position: relative;
  width: 100%;
  max-width: var(--w);
  margin: 0 auto;
  padding: clamp(2.5rem, 5vw, 4rem) var(--pad-x) clamp(1.75rem, 4vw, 2.75rem);
  display: grid;
  grid-template-columns: minmax(240px, 1.1fr) minmax(0, 2.4fr);
  gap: clamp(2rem, 4vw, 3.5rem);
}

.footer-brand { display: flex; flex-direction: column; gap: 0.55rem; }

.footer-brand__name {
  font-family: var(--font-head);
  font-weight: 900;
  font-stretch: condensed;
  font-size: 1.375rem;
  letter-spacing: -0.01em;
  color: var(--c-ink);
}

.footer-brand__sub {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: var(--c-cyan);
}

.footer-brand__note {
  max-width: 34ch;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--c-mist);
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(1.25rem, 2.5vw, 2rem);
}

.footer-col__title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding-bottom: 0.6rem;
  margin-bottom: 0.85rem;
  border-bottom: 1px solid var(--c-line);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--c-mist);
}

.footer-col__title::before {
  content: "";
  width: 14px;
  height: 2px;
  background: var(--c-cyan);
  flex: 0 0 auto;
}

.footer-list { display: flex; flex-direction: column; }

.footer-link {
  display: block;
  padding: 0.32rem 0;
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--c-mist);
  transition: color 0.16s ease, transform 0.16s ease;
}

.footer-link--mono {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-variant-numeric: tabular-nums;
  word-break: break-all;
}

.footer-link:hover,
.footer-link:focus-visible {
  color: var(--c-cyan);
  transform: translateX(3px);
}

.footer-base {
  position: relative;
  width: 100%;
  max-width: var(--w);
  margin: 0 auto;
  padding: 1rem var(--pad-x) 2rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  border-top: 1px solid var(--c-line);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.03em;
  color: var(--c-mist);
  font-variant-numeric: tabular-nums;
}

.footer-base__icp { color: var(--c-line); }
.footer-base__icp::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  margin-right: 0.5rem;
  background: var(--c-amber);
  vertical-align: middle;
}

/* 返回顶部 */
.to-top {
  position: fixed;
  right: clamp(0.75rem, 2vw, 1.5rem);
  bottom: clamp(0.75rem, 2vw, 1.5rem);
  z-index: 70;
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--c-steel);
  border: 1px solid var(--c-line);
  color: var(--c-cyan);
  font-family: var(--font-mono);
  font-size: 1rem;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease, border-color 0.2s ease;
}

.to-top[data-visible="true"] {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.to-top:hover { border-color: var(--c-cyan); }

/* ---------- 09 响应式 ---------- */
@media (max-width: 1080px) {
  .footer-inner { grid-template-columns: minmax(0, 1fr); }
  .footer-nav { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

@media (max-width: 980px) {
  .grid--split,
  .grid--split-rev { grid-template-columns: minmax(0, 1fr); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 900px) {
  :root { --notch-lg: 18px; }

  .header-strip { display: none; }

  .nav-toggle { display: inline-flex; }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    margin-left: 0;
    padding: 0.4rem var(--pad-x) 1.15rem;
    background: var(--c-steel);
    border-top: 1px solid var(--c-line);
    border-bottom: 1px solid var(--c-line);
    box-shadow: 0 26px 52px rgba(3, 9, 20, 0.6);
    max-height: calc(100vh - 66px);
    overflow-y: auto;
    overscroll-behavior: contain;
  }

  .site-nav[data-open="true"] { display: flex; }

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

  .nav-link {
    justify-content: flex-start;
    padding: 0.85rem 0.2rem;
    font-size: 0.9375rem;
    border-bottom: 1px solid rgba(44, 74, 115, 0.6);
  }

  .nav-link__id { width: 2.1rem; flex: 0 0 auto; }

  .nav-link[aria-current="page"] {
    border-bottom-color: var(--c-cyan);
    background: rgba(52, 224, 208, 0.06);
  }

  .nav-actions {
    flex-direction: column;
    align-items: stretch;
    gap: 0.5rem;
    margin: 0.9rem 0 0;
  }

  .nav-actions .btn { width: 100%; }
  .nav-actions .btn--ghost { display: inline-flex; }

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

@media (max-width: 620px) {
  .grid--2,
  .grid--3 { grid-template-columns: minmax(0, 1fr); }

  .brand__sub { display: none; }

  .index-item {
    grid-template-columns: 3.6rem minmax(0, 1fr);
  }

  .index-item__meta {
    grid-column: 2 / -1;
    white-space: normal;
  }

  .footer-nav { grid-template-columns: minmax(0, 1fr); }

  .footer-base { justify-content: flex-start; }
}

@media (max-width: 380px) {
  .nav-toggle__label { display: none; }
  .brand__index { width: 26px; height: 23px; font-size: 0.625rem; }
}

/* ---------- 10 降低动效 ---------- */
@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;
    transition-delay: 0ms !important;
  }

  .reveal,
  html.js-motion .reveal:not(.is-visible) {
    opacity: 1 !important;
    transform: none !important;
  }

  .skip-link { transition: none; }
  .to-top { transition: opacity 0.001ms, visibility 0.001ms; }
}