/* =========================================================
   博鱼体育 · 全站共享样式表 /assets/site.css
   令牌 → 重置 → 中文排版 → 工具 → 零件 → 头部 → 页脚 → 响应式
   ========================================================= */

/* ---------- 1. 设计令牌 ---------- */
:root {
  --navy-950: #050F1A;
  --navy-800: #0C2338;
  --navy-600: #16456B;
  --orange-500: #FF5A1F;
  --orange-200: #FFB48C;
  --sand-100: #F1EEE7;
  --sand-300: #CFC9BC;
  --grass-600: #2E6B4F;
  --mist-400: #8C9BAB;
  --white: #FFFFFF;

  --font-heading: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-body: var(--font-heading);
  --font-mono: "IBM Plex Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;

  --header-h: 56px;
  --shell-max: 1320px;
  --gutter: clamp(16px, 3.6vw, 48px);
  --read-max: 68ch;

  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
  --t-fast: 0.18s;
  --t-base: 0.28s;
  --t-slow: 0.4s;

  --line-on-dark: rgba(140, 155, 171, 0.22);
  --line-on-light: rgba(5, 15, 26, 0.14);

  --radius-1: 3px;
  --radius-2: 6px;

  --shadow-card: 0 12px 32px -22px rgba(5, 15, 26, 0.55);
}

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

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

body {
  margin: 0;
  background: var(--sand-100);
  color: var(--navy-950);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body,
button,
input,
select,
textarea { font-family: inherit; }

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

img { height: auto; }

a { color: inherit; }

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

button { font: inherit; color: inherit; }

hr {
  border: 0;
  border-top: 1px solid var(--line-on-light);
  margin: 2.4rem 0;
}

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

::selection {
  background: var(--orange-500);
  color: var(--navy-950);
}

/* ---------- 3. 中文排版与标题 ---------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.14;
  margin: 0 0 0.6em;
  text-wrap: balance;
}

h1 { font-size: clamp(34px, 5.4vw, 66px); }
h2 { font-size: clamp(26px, 3.4vw, 44px); }
h3 { font-size: clamp(20px, 2.2vw, 28px); }
h4 { font-size: clamp(17px, 1.5vw, 20px); letter-spacing: -0.01em; }
h5 { font-size: 16px; letter-spacing: 0; }
h6 { font-size: 14px; letter-spacing: 0.02em; }

p { margin: 0 0 1.1em; }
p:last-child { margin-bottom: 0; }

strong, b { font-weight: 700; }

small { font-size: 13px; line-height: 1.6; }

.prose,
.u-prose {
  max-width: var(--read-max);
  font-size: 16px;
  line-height: 1.85;
}

.prose > h2,
.u-prose > h2 { margin-top: 1.6em; }

.prose ul,
.prose ol,
.u-prose ul,
.u-prose ol {
  margin: 0 0 1.2em;
  padding-left: 1.25em;
}

.prose li,
.u-prose li { margin-bottom: 0.4em; }

blockquote {
  margin: 1.8em 0;
  padding: 4px 0 4px 20px;
  border-left: 3px solid var(--orange-500);
  color: var(--navy-800);
  font-size: 17px;
}

code,
kbd,
samp {
  font-family: var(--font-mono);
  font-size: 0.92em;
  font-variant-numeric: tabular-nums;
}

/* ---------- 4. 工具类 ---------- */
.u-visually-hidden {
  position: absolute !important;
  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;
}

.u-text-mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.u-accent { color: var(--orange-500); }

.u-stack { display: grid; gap: clamp(14px, 2vw, 24px); }

.container {
  width: 100%;
  max-width: var(--shell-max);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: clamp(20px, 3vw, 36px);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--orange-500);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 2px;
  background: var(--orange-500);
  flex: none;
}

/* ---------- 5. 分屏骨架与斜切 ---------- */
.split {
  display: grid;
  grid-template-columns: minmax(260px, 34%) minmax(0, 1fr);
  align-items: stretch;
}

.split--wide-struct { grid-template-columns: minmax(300px, 40%) minmax(0, 1fr); }
.split--narrow-struct { grid-template-columns: minmax(240px, 28%) minmax(0, 1fr); }

.split__struct {
  position: relative;
  background: var(--navy-950);
  color: var(--sand-100);
  padding: clamp(28px, 4vw, 60px) clamp(20px, 3vw, 46px);
  overflow: hidden;
}

.split__struct::after {
  content: "";
  position: absolute;
  top: 0;
  right: -1px;
  bottom: 0;
  width: clamp(20px, 3.4vw, 56px);
  background: var(--navy-950);
  clip-path: polygon(0 0, 100% 0, 0 100%);
  z-index: 2;
  pointer-events: none;
}

.split__content {
  position: relative;
  background: var(--sand-100);
  color: var(--navy-950);
  padding: clamp(28px, 4vw, 60px) clamp(20px, 4vw, 68px);
}

.slant-divider {
  height: clamp(26px, 4.5vw, 58px);
  background: var(--navy-950);
  clip-path: polygon(0 0, 100% 0, 100% 100%, 0 46%);
}

.grid { display: grid; gap: clamp(16px, 2.4vw, 32px); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid--asym { grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr); }
.grid--sticker { grid-template-columns: repeat(12, minmax(0, 1fr)); }

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 38px;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: var(--radius-1);
  background: transparent;
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1;
  white-space: nowrap;
  text-decoration: none;
  cursor: pointer;
  transition: background-color var(--t-fast) var(--ease), color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease), transform var(--t-fast) var(--ease);
}

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

.btn--primary {
  background: var(--orange-500);
  color: var(--navy-950);
}

.btn--primary:hover { background: var(--orange-200); }

.btn--ghost {
  border-color: var(--line-on-dark);
  color: var(--sand-100);
}

.btn--ghost:hover {
  border-color: var(--orange-500);
  color: var(--orange-200);
}

.btn--outline {
  border-color: var(--line-on-light);
  color: var(--navy-950);
}

.btn--outline:hover {
  border-color: var(--navy-950);
  background: var(--navy-950);
  color: var(--sand-100);
}

.btn--sm { height: 32px; padding: 0 13px; font-size: 13px; }
.btn--lg { height: 48px; padding: 0 26px; font-size: 16px; }

/* ---------- 7. 通用零件 ---------- */

/* 比分牌 */
.scoreboard {
  position: relative;
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  padding: clamp(14px, 1.8vw, 24px) clamp(18px, 2.2vw, 30px) clamp(14px, 1.8vw, 22px) clamp(22px, 2.6vw, 34px);
  background: var(--navy-950);
  color: var(--white);
  border-radius: var(--radius-1);
  overflow: hidden;
}

.scoreboard::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  width: 4px;
  background: var(--orange-500);
}

.scoreboard--flush { background: var(--navy-800); }

.scoreboard__label {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist-400);
}

.scoreboard__row {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.scoreboard__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(34px, 5vw, 66px);
  line-height: 0.94;
  letter-spacing: -0.035em;
}

.scoreboard__unit {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--orange-500);
}

.scoreboard__note {
  font-size: 12px;
  color: var(--mist-400);
  line-height: 1.5;
}

/* 索引签 */
.index-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: 1px solid currentColor;
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  line-height: 1.6;
  white-space: nowrap;
}

.index-tag--round { color: var(--orange-500); }
.index-tag--city { color: var(--navy-600); }
.index-tag--ok { color: var(--grass-600); }
.index-tag--neutral { color: var(--mist-400); }

.split__struct .index-tag--city,
.site-footer .index-tag--city { color: var(--mist-400); }

/* 数据条 */
.data-bar {
  display: grid;
  gap: 7px;
  width: 100%;
}

.data-bar__track {
  position: relative;
  height: 8px;
  background: rgba(22, 69, 107, 0.18);
  border-radius: 99px;
  overflow: hidden;
}

.data-bar__fill {
  position: absolute;
  inset: 0 auto 0 0;
  width: 0;
  background: var(--orange-500);
  border-radius: 99px;
  transition: width var(--t-slow) var(--ease);
}

.data-bar__fill--green { background: var(--grass-600); }
.data-bar__fill--navy { background: var(--navy-600); }

.data-bar__meta {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  color: var(--navy-600);
}

.split__struct .data-bar__track { background: rgba(140, 155, 171, 0.2); }
.split__struct .data-bar__meta,
.site-footer .data-bar__meta { color: var(--mist-400); }

/* 记录卡 */
.record-card {
  position: relative;
  padding: clamp(18px, 2vw, 26px);
  background: var(--white);
  border: 1px solid var(--sand-300);
  border-radius: var(--radius-1);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  transition: border-color var(--t-fast) var(--ease), transform var(--t-fast) var(--ease);
}

.record-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--orange-500);
}

.record-card:hover {
  border-color: var(--navy-600);
  transform: translateY(-2px);
}

.record-card--ok::before { background: var(--grass-600); }
.record-card--quiet::before { background: var(--navy-600); }

.record-card--dark {
  background: var(--navy-800);
  border-color: var(--line-on-dark);
  color: var(--sand-100);
}

.record-card__title {
  margin: 0 0 6px;
  font-size: clamp(17px, 1.5vw, 20px);
  font-weight: 800;
  letter-spacing: -0.015em;
  line-height: 1.3;
}

.record-card__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 14px;
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--navy-600);
}

.record-card--dark .record-card__meta { color: var(--mist-400); }

.record-card__body {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.75;
}

/* 图片容器（页面阶段放 <img>） */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border-radius: var(--radius-1);
  background: var(--navy-800);
  isolation: isolate;
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(135deg, rgba(140, 155, 171, 0.1) 0 2px, transparent 2px 13px);
  pointer-events: none;
  z-index: 0;
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--portrait { aspect-ratio: 4 / 5; }

.media-frame__img {
  position: relative;
  z-index: 1;
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame__caption {
  position: absolute;
  z-index: 2;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 26px 16px 14px;
  background: linear-gradient(0deg, rgba(5, 15, 26, 0.9), rgba(5, 15, 26, 0));
  color: var(--sand-100);
  font-size: 13px;
  line-height: 1.55;
}

.media-frame__tag {
  position: absolute;
  z-index: 2;
  top: 14px;
  left: 14px;
}

/* 玻璃层 */
.glass {
  background: rgba(12, 35, 56, 0.58);
  -webkit-backdrop-filter: blur(14px) saturate(1.1);
  backdrop-filter: blur(14px) saturate(1.1);
  border: 1px solid var(--line-on-dark);
  border-radius: var(--radius-1);
  color: var(--sand-100);
}

.glass--light {
  background: rgba(241, 238, 231, 0.74);
  border-color: var(--line-on-light);
  color: var(--navy-950);
}

/* 面包屑 */
.breadcrumbs {
  padding: 14px 0;
  font-size: 13px;
  color: var(--navy-600);
}

.breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  list-style: none;
}

.breadcrumbs__list > li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--sand-300);
}

.breadcrumbs__link {
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease);
}

.breadcrumbs__link:hover {
  color: var(--orange-500);
  border-bottom-color: var(--orange-500);
}

.breadcrumbs__current {
  font-family: var(--font-mono);
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--navy-950);
}

/* 显现动效协议 */
html.js [data-reveal] {
  opacity: 0;
  transform: translate3d(0, 18px, 0);
  transition: opacity 0.36s var(--ease), transform 0.36s var(--ease);
}

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

/* ---------- 8. 焦点与跳转 ---------- */
:focus-visible {
  outline: 2px solid var(--orange-500);
  outline-offset: 2px;
  border-radius: 2px;
}

.skip-link {
  position: fixed;
  top: -72px;
  left: 12px;
  z-index: 300;
  padding: 10px 18px;
  background: var(--orange-500);
  color: var(--navy-950);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  border-radius: 0 0 var(--radius-2) var(--radius-2);
  transition: top var(--t-base) var(--ease);
}

.skip-link:focus { top: 0; }

/* ---------- 9. 头部命令栏 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  background: var(--navy-950);
  color: var(--sand-100);
  border-bottom: 1px solid var(--line-on-dark);
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.6vw, 26px);
  width: 100%;
  max-width: var(--shell-max);
  margin: 0 auto;
  padding: 0 var(--gutter);
  height: var(--header-h);
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: none;
  color: var(--white);
  text-decoration: none;
}

.brand__mark {
  display: grid;
  place-items: center;
  flex: none;
  width: 30px;
  height: 30px;
  background: var(--orange-500);
  color: var(--navy-950);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1;
  clip-path: polygon(13% 0, 100% 0, 87% 100%, 0 100%);
}

.brand__text {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 1px;
}

.brand__name {
  font-family: var(--font-heading);
  font-size: 16px;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.brand__tagline {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--mist-400);
  line-height: 1.2;
}

.brand--footer .brand__mark { width: 34px; height: 34px; font-size: 14px; }
.brand--footer .brand__name { font-size: 18px; }

/* 主导航 */
.site-nav { margin-left: auto; }

.site-nav__list {
  display: flex;
  align-items: stretch;
  gap: 0;
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav__item { display: flex; }

.site-nav__link {
  position: relative;
  display: flex;
  align-items: center;
  gap: 7px;
  height: var(--header-h);
  padding: 0 clamp(8px, 1.05vw, 14px);
  color: var(--sand-300);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.01em;
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--t-fast) var(--ease), background-color var(--t-fast) var(--ease);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  background: var(--orange-500);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.22s var(--ease);
}

.site-nav__link:hover {
  color: var(--white);
  background: rgba(22, 69, 107, 0.38);
}

.site-nav__link:hover::after { transform: scaleX(1); }

.site-nav__link[aria-current="page"] {
  color: var(--white);
  font-weight: 700;
}

.site-nav__link[aria-current="page"]::after { transform: scaleX(1); }

.site-nav__index {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--mist-400);
  opacity: 0.62;
  transition: color var(--t-fast) var(--ease), opacity var(--t-fast) var(--ease);
}

.site-nav__link:hover .site-nav__index { opacity: 1; }

.site-nav__link[aria-current="page"] .site-nav__index {
  color: var(--orange-500);
  opacity: 1;
}

/* 右侧轮次状态条 */
.site-header__status {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: none;
  margin-left: clamp(8px, 1.4vw, 22px);
  padding-left: clamp(10px, 1.6vw, 22px);
  border-left: 1px solid var(--line-on-dark);
}

.round-status {
  display: flex;
  align-items: baseline;
  gap: 8px;
  text-decoration: none;
  color: var(--sand-100);
  transition: color var(--t-fast) var(--ease);
}

.round-status__label {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--mist-400);
}

.round-status__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--orange-500);
}

.round-status__time {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--mist-400);
}

.round-status:hover .round-status__value { color: var(--orange-200); }

.site-header__cta { flex: none; }

/* 移动菜单按钮 */
.nav-toggle {
  display: none;
  flex: none;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  margin-left: auto;
  padding: 0;
  background: transparent;
  border: 1px solid var(--line-on-dark);
  border-radius: var(--radius-1);
  color: var(--sand-100);
  cursor: pointer;
  transition: border-color var(--t-fast) var(--ease), color var(--t-fast) var(--ease);
}

.nav-toggle:hover { border-color: var(--orange-500); color: var(--orange-200); }

.nav-toggle__bars {
  display: block;
  position: relative;
  width: 18px;
  height: 2px;
  background: currentColor;
  box-shadow: 0 -6px 0 currentColor, 0 6px 0 currentColor;
  transition: transform var(--t-base) var(--ease), box-shadow var(--t-base) var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars {
  transform: rotate(45deg);
  box-shadow: 0 0 0 currentColor, 0 0 0 currentColor;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after {
  content: "";
  position: absolute;
  inset: 0;
  background: currentColor;
  transform: rotate(90deg);
}

/* 阅读进度线 */
.scroll-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  background: var(--orange-500);
  transform: scaleX(0);
  transform-origin: left center;
  will-change: transform;
  pointer-events: none;
}

/* ---------- 10. 返回顶部（JS 创建） ---------- */
.back-to-top {
  position: fixed;
  right: clamp(14px, 2vw, 28px);
  bottom: clamp(14px, 2vw, 28px);
  z-index: 110;
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  padding: 0;
  background: var(--navy-950);
  color: var(--sand-100);
  border: 1px solid var(--line-on-dark);
  border-radius: var(--radius-1);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(14px);
  transition: opacity var(--t-base) var(--ease), transform var(--t-base) var(--ease), visibility var(--t-base) var(--ease), background-color var(--t-fast) var(--ease), color var(--t-fast) var(--ease);
}

.back-to-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.back-to-top:hover {
  background: var(--orange-500);
  color: var(--navy-950);
  border-color: var(--orange-500);
}

.back-to-top__icon {
  display: block;
  width: 11px;
  height: 11px;
  margin-top: 4px;
  border-left: 2px solid currentColor;
  border-top: 2px solid currentColor;
  transform: rotate(45deg);
}

/* ---------- 11. 页脚 ---------- */
.site-footer {
  position: relative;
  background: var(--navy-950);
  color: var(--sand-300);
  border-top: 1px solid var(--line-on-dark);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: min(520px, 48%);
  height: 100%;
  background: linear-gradient(160deg, rgba(12, 35, 56, 0.95), rgba(5, 15, 26, 0) 72%);
  clip-path: polygon(0 0, 100% 0, 62% 100%, 0 100%);
  pointer-events: none;
}

.site-footer::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: clamp(80px, 12%, 180px);
  height: 3px;
  background: var(--orange-500);
  pointer-events: none;
}

.site-footer__inner {
  position: relative;
  z-index: 1;
  max-width: var(--shell-max);
  margin: 0 auto;
  padding: clamp(40px, 5.5vw, 76px) var(--gutter) clamp(22px, 3vw, 34px);
}

.site-footer__top {
  display: grid;
  grid-template-columns: minmax(240px, 1.1fr) minmax(0, 2fr);
  gap: clamp(28px, 5vw, 76px);
  padding-bottom: clamp(30px, 4vw, 52px);
  border-bottom: 1px solid var(--line-on-dark);
}

.site-footer__brand { display: grid; gap: 18px; align-content: start; }

.site-footer__intro {
  margin: 0;
  max-width: 34ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--mist-400);
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(20px, 3vw, 44px);
}

.footer-nav__title {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--orange-200);
}

.footer-nav__list {
  display: grid;
  gap: 11px;
  list-style: none;
}

.footer-nav__link {
  position: relative;
  display: inline-block;
  padding-left: 15px;
  color: var(--sand-300);
  font-size: 15px;
  line-height: 1.6;
  text-decoration: none;
  transition: color var(--t-fast) var(--ease);
}

.footer-nav__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 6px;
  height: 1px;
  background: var(--navy-600);
  transition: width var(--t-fast) var(--ease), background-color var(--t-fast) var(--ease);
}

.footer-nav__link:hover { color: var(--white); }
.footer-nav__link:hover::before { width: 11px; background: var(--orange-500); }

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: clamp(20px, 3vw, 48px);
  padding-top: clamp(22px, 3vw, 34px);
}

.site-footer__contact { display: grid; gap: 14px; max-width: 62ch; }

.footer-note {
  margin: 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--mist-400);
}

.footer-contact {
  display: grid;
  gap: 8px;
  list-style: none;
}

.footer-contact__item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  font-size: 13px;
  line-height: 1.7;
}

.footer-contact__key {
  flex: none;
  min-width: 34px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--navy-600);
  text-transform: uppercase;
}

.split__struct .footer-contact__key,
.site-footer .footer-contact__key { color: var(--mist-400); }

.footer-contact__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  color: var(--sand-100);
  word-break: break-word;
}

.site-footer__legal {
  display: grid;
  gap: 6px;
  justify-items: start;
  text-align: left;
}

.footer-meta {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--mist-400);
}

/* ---------- 12. 响应式 ---------- */
@media (max-width: 1180px) {
  .site-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    margin-left: 0;
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
    background: var(--navy-950);
    border-bottom: 1px solid var(--line-on-dark);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(-10px);
    transition: opacity 0.22s var(--ease), transform 0.22s var(--ease), visibility 0.22s var(--ease);
  }

  .site-nav[data-open] {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: none;
  }

  .site-nav__list {
    flex-direction: column;
    padding: 8px var(--gutter) 22px;
  }

  .site-nav__item { display: block; }

  .site-nav__link {
    height: auto;
    padding: 15px 4px;
    font-size: 16px;
    border-bottom: 1px solid rgba(140, 155, 171, 0.14);
  }

  .site-nav__link::after { display: none; }

  .site-nav__link[aria-current="page"] { color: var(--orange-500); }
  .site-nav__link[aria-current="page"] .site-nav__index { color: var(--orange-500); }

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

  html.is-nav-open,
  html.is-nav-open body { overflow: hidden; }
}

@media (max-width: 1080px) {
  .split,
  .split--wide-struct,
  .split--narrow-struct {
    grid-template-columns: minmax(0, 1fr);
  }

  .split__struct::after {
    top: auto;
    left: 0;
    right: 0;
    bottom: -1px;
    width: 100%;
    height: clamp(18px, 4vw, 42px);
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 0);
  }

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

@media (max-width: 900px) {
  .site-header__status { display: none; }
  .site-header__cta { display: none; }
}

@media (max-width: 760px) {
  :root { --header-h: 54px; }

  body { font-size: 15.5px; line-height: 1.78; }

  h1 { font-size: clamp(28px, 8.4vw, 40px); }
  h2 { font-size: clamp(23px, 6.4vw, 30px); }
  h3 { font-size: clamp(19px, 5vw, 23px); }

  .grid--2,
  .grid--3,
  .grid--4,
  .grid--asym { grid-template-columns: minmax(0, 1fr); }

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

  .scoreboard { width: 100%; }

  .brand__tagline { display: none; }

  .site-footer__bottom { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 480px) {
  .footer-nav { grid-template-columns: minmax(0, 1fr); }
  .site-nav__link { font-size: 15px; }
  .btn { padding: 0 15px; }
}

@media (min-width: 1181px) {
  .site-nav { display: block; }
}

/* ---------- 13. 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;
  }

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

  .scroll-progress { transition: none; }
}

@media print {
  .site-header,
  .site-footer,
  .back-to-top,
  .skip-link { display: none !important; }
}