/* ==========================================================================
   球友会中心 · 全站共享样式 /assets/site.css
   01 令牌  02 基础重置  03 排版  04 头部与轨道  05 导览
   06 页脚  07 按钮  08 面板与切角  09 编号与条款
   10 索引 / 折叠 / 滑选条  11 媒体容器  12 容器与网格  13 工具与动效
   ========================================================================== */

/* ---------- 01 令牌 ---------- */
:root {
  --ink-900: #08131A;
  --ink-800: #0B1B22;
  --pine-900: #0E2F2A;
  --pine-700: #123A33;
  --moss-600: #1E5348;
  --ice-600: #2E8FA8;
  --ice-300: #8AD4E3;
  --amber-400: #E8B14A;
  --coral-500: #E4593F;
  --stone-400: #8D9A99;
  --paper-100: #EDE7DA;

  --text: #D9E2E0;
  --text-dim: #9FB0AE;
  --line: rgba(138, 212, 227, 0.15);
  --line-2: rgba(138, 212, 227, 0.30);

  --rail-w: 276px;
  --pad: clamp(18px, 4.2vw, 60px);
  --gap: clamp(14px, 1.6vw, 24px);
  --cut: 12px;
  --cut-lg: 22px;

  --font-head: "Archivo Narrow", "Oswald", "Noto Sans SC", "Source Han Sans SC", "PingFang SC", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", "Roboto Mono", ui-monospace, "SFMono-Regular", Consolas, monospace;

  --t: 220ms;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 02 基础重置 ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 88px;
}

body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0.012em;
  background-color: var(--ink-800);
  background-image:
    linear-gradient(rgba(138, 212, 227, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(138, 212, 227, 0.045) 1px, transparent 1px),
    radial-gradient(120% 78% at 78% -12%, rgba(46, 143, 168, 0.18), transparent 62%);
  background-size: 72px 72px, 72px 72px, 100% 100%;
  background-repeat: repeat, repeat, no-repeat;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

img, svg, video { display: block; max-width: 100%; }
button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; padding: 0; cursor: pointer; }
ul, ol { margin: 0; padding: 0; list-style: none; }
h1, h2, h3, h4, p, figure, blockquote, dl, dd { margin: 0; }

a {
  color: var(--ice-300);
  text-decoration: none;
  transition: color var(--t) var(--ease), border-color var(--t) var(--ease);
}
a:hover { color: #FFFFFF; text-decoration: underline; text-underline-offset: 0.25em; }

:focus-visible {
  outline: 2px solid var(--ice-300);
  outline-offset: 2px;
  border-radius: 2px;
}
:focus:not(:focus-visible) { outline: none; }

::selection { background: var(--ice-600); color: var(--ink-900); }

/* ---------- 03 排版 ---------- */
.h-display {
  font-family: var(--font-head);
  font-weight: 300;
  font-size: clamp(40px, 7.4vw, 88px);
  line-height: 0.98;
  letter-spacing: -0.012em;
  color: var(--paper-100);
}

.h1 {
  font-family: var(--font-head);
  font-weight: 400;
  font-size: clamp(30px, 4.4vw, 52px);
  line-height: 1.1;
  letter-spacing: -0.005em;
  color: var(--paper-100);
}

.h2 {
  font-family: var(--font-head);
  font-weight: 500;
  font-size: clamp(22px, 2.6vw, 32px);
  line-height: 1.22;
  color: var(--paper-100);
}

.h3 {
  font-size: 19px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--paper-100);
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ice-300);
}

.lede {
  font-size: clamp(16.5px, 1.4vw, 18px);
  line-height: 1.8;
  color: rgba(237, 231, 218, 0.86);
  max-width: 38em;
}

.num { font-family: var(--font-mono); font-weight: 600; font-variant-numeric: tabular-nums; letter-spacing: 0.02em; }
.num--amber { color: var(--amber-400); }
.num--ice { color: var(--ice-300); }
.num--coral { color: var(--coral-500); }

.prose {
  max-width: 38em;
  font-size: 16.5px;
  line-height: 1.85;
  color: rgba(237, 231, 218, 0.86);
}
.prose > * + * { margin-top: 1.05em; }
.prose h2, .prose h3 { color: var(--paper-100); }
.prose ul, .prose ol { padding-left: 1.3em; list-style: disc; }
.prose ol { list-style: decimal; }
.prose li + li { margin-top: 0.4em; }
.prose strong { color: var(--paper-100); }
.prose blockquote {
  border-left: 2px solid var(--amber-400);
  padding: 4px 0 4px 18px;
  color: var(--text-dim);
}

/* ---------- 04 头部与轨道 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: transparent;
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -60px;
  z-index: 90;
  padding: 10px 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--ink-900);
  background: var(--amber-400);
  border-radius: 2px;
  transition: top var(--t) var(--ease);
}
.skip-link:focus { top: 12px; text-decoration: none; }

.site-header__bar {
  position: relative;
  z-index: 3;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 64px;
  padding: 10px var(--pad);
  background: rgba(11, 27, 34, 0.42);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
  transition: background var(--t) var(--ease), border-color var(--t) var(--ease);
}

.site-header[data-scrolled="true"] .site-header__bar {
  background: var(--pine-700);
  border-bottom-color: var(--line-2);
  -webkit-backdrop-filter: none;
  backdrop-filter: none;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  min-width: 0;
  color: var(--paper-100);
}
.brand:hover { text-decoration: none; color: var(--paper-100); }

.brand__mark {
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 600;
  line-height: 1;
  color: var(--ink-900);
  background: linear-gradient(150deg, var(--ice-300), var(--ice-600));
  clip-path: polygon(8px 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%, 0 8px);
  transition: background var(--t) var(--ease);
}
.brand:hover .brand__mark { background: linear-gradient(150deg, var(--amber-400), var(--ice-600)); }

.brand__text { display: flex; flex-direction: column; gap: 1px; min-width: 0; }

.brand__name {
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: 0.07em;
  color: var(--paper-100);
}

.brand__line {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  line-height: 1.3;
  color: var(--stone-400);
  white-space: nowrap;
}

.brand--lg .brand__mark { width: 42px; height: 42px; font-size: 23px; }
.brand--lg .brand__name { font-size: 20px; letter-spacing: 0.08em; }

.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 9px 13px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--paper-100);
  background: rgba(46, 143, 168, 0.16);
  border: 1px solid var(--line-2);
  border-radius: 2px;
  transition: background var(--t) var(--ease), border-color var(--t) var(--ease);
}
.nav-toggle:hover { background: rgba(46, 143, 168, 0.3); border-color: var(--ice-300); }

.nav-toggle__bars {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  width: 17px;
  height: 12px;
}
.nav-toggle__bars span {
  display: block;
  height: 1.5px;
  width: 100%;
  background: var(--ice-300);
  transition: transform var(--t) var(--ease), opacity var(--t) var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) { transform: translateY(5.2px) rotate(38deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) { transform: translateY(-5.2px) rotate(-38deg); }

.site-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: rgba(138, 212, 227, 0.12);
  pointer-events: none;
}
.site-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, var(--ice-600), var(--amber-400));
  transform: scaleX(var(--p, 0));
  transform-origin: 0 50%;
}

.rail-track { display: none; }

/* ---------- 05 导览 ---------- */
.site-nav {
  position: fixed;
  inset: 0;
  z-index: 2;
  display: flex;
  flex-direction: column;
  gap: 20px;
  padding: 96px var(--pad) 40px;
  overflow-y: auto;
  background: linear-gradient(180deg, var(--pine-900) 0%, var(--ink-800) 82%);
  border-right: 1px solid var(--line-2);
  opacity: 0;
  visibility: hidden;
  transform: translateX(-14px);
  transition: opacity var(--t) var(--ease), transform var(--t) var(--ease), visibility 0s linear var(--t);
}
.site-nav[data-open="true"] {
  opacity: 1;
  visibility: visible;
  transform: none;
  transition: opacity var(--t) var(--ease), transform var(--t) var(--ease), visibility 0s;
}

.site-nav__eyebrow {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--stone-400);
}

.site-nav__list { display: flex; flex-direction: column; gap: 2px; }

.site-nav__link {
  position: relative;
  display: grid;
  grid-template-columns: 38px 1fr;
  align-items: center;
  gap: 10px;
  padding: 11px 34px 11px 10px;
  font-size: 15.5px;
  letter-spacing: 0.02em;
  color: rgba(237, 231, 218, 0.82);
  border-left: 2px solid transparent;
  transition: color var(--t) var(--ease), background var(--t) var(--ease), border-color var(--t) var(--ease);
}
.site-nav__link::after {
  content: "";
  position: absolute;
  right: 12px;
  top: 50%;
  width: 12px;
  height: 1px;
  background: var(--ice-300);
  transform: scaleX(0);
  transform-origin: 100% 50%;
  transition: transform var(--t) var(--ease);
}
.site-nav__link:hover,
.site-nav__link:focus-visible {
  color: #FFFFFF;
  text-decoration: none;
  background: rgba(138, 212, 227, 0.1);
  border-left-color: var(--ice-600);
}
.site-nav__link:hover::after { transform: scaleX(1); }

.site-nav__link[aria-current="page"] {
  color: #FFFFFF;
  background: linear-gradient(90deg, rgba(46, 143, 168, 0.32), rgba(46, 143, 168, 0));
  border-left-color: var(--amber-400);
}
.site-nav__link[aria-current="page"]::after { transform: scaleX(1); background: var(--amber-400); }
.site-nav__link[aria-current="page"] .site-nav__num { color: var(--amber-400); }

.site-nav__num {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--stone-400);
  transition: color var(--t) var(--ease);
}

.site-nav__label { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.site-nav__foot {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-top: auto;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.site-nav__legend {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--stone-400);
}
.site-nav__legend b { font-weight: 600; color: var(--amber-400); }

/* ---------- 06 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 7vw, 96px);
  background: linear-gradient(180deg, var(--pine-900) 0%, var(--ink-800) 100%);
  border-top: 1px solid var(--line-2);
  color: var(--text-dim);
}

.footer__rule {
  height: 6px;
  background: repeating-linear-gradient(115deg, rgba(138, 212, 227, 0.55) 0 2px, transparent 2px 10px);
  opacity: 0.55;
}

.footer__inner {
  display: grid;
  gap: clamp(28px, 4vw, 52px);
  width: 100%;
  max-width: 1180px;
  margin-inline: auto;
  padding: clamp(36px, 5vw, 64px) var(--pad) clamp(28px, 3.4vw, 44px);
}

.footer__brand { min-width: 0; }

.footer__note {
  margin-top: 16px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-dim);
  max-width: 24em;
}

.stat-list { display: flex; flex-wrap: wrap; gap: 12px 24px; margin-top: 20px; }
.stat { display: flex; flex-direction: column; gap: 3px; min-width: 62px; }
.stat__k {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  color: var(--stone-400);
}
.stat__v {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 600;
  line-height: 1;
  color: var(--amber-400);
}

.footer__cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px var(--gap);
}

.footer__title {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ice-300);
}

.footer__list { display: flex; flex-direction: column; gap: 9px; margin-top: 16px; }

.footer__list a {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 1px 0;
  font-size: 14.5px;
  color: rgba(237, 231, 218, 0.8);
  border-bottom: 1px solid transparent;
}
.footer__list a::before {
  content: "";
  flex: 0 0 auto;
  width: 6px;
  height: 6px;
  background: var(--ice-600);
  transform: rotate(45deg);
  transition: background var(--t) var(--ease);
}
.footer__list a:hover {
  color: #FFFFFF;
  text-decoration: none;
  border-bottom-color: var(--line-2);
}
.footer__list a:hover::before { background: var(--amber-400); }

.footer__list--plain li {
  display: grid;
  grid-template-columns: 54px 1fr;
  gap: 10px;
  align-items: start;
  font-size: 14px;
}
.footer__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--stone-400);
  padding-top: 2px;
}
.footer__v { color: rgba(237, 231, 218, 0.84); word-break: break-word; }

.footer__reach { display: flex; flex-direction: column; align-items: flex-start; gap: 4px; }
.footer__reach .btn { margin-top: 20px; }

.footer__base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  max-width: 1180px;
  margin-inline: auto;
  padding: 18px var(--pad) 26px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--stone-400);
}
.footer__legal { display: flex; flex-wrap: wrap; gap: 6px 18px; }
.footer__legal a { color: var(--stone-400); }
.footer__legal a:hover { color: var(--ice-300); }
.footer__icp { color: var(--stone-400); }

/* ---------- 07 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  font-family: var(--font-body);
  font-size: 14.5px;
  font-weight: 600;
  letter-spacing: 0.04em;
  line-height: 1.2;
  color: var(--paper-100);
  background: transparent;
  border: 1px solid var(--line-2);
  border-radius: 2px;
  cursor: pointer;
  transition: background var(--t) var(--ease), color var(--t) var(--ease),
              border-color var(--t) var(--ease), transform var(--t) var(--ease);
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }

.btn--primary {
  background: var(--ice-600);
  border-color: var(--ice-600);
  color: #04141A;
}
.btn--primary:hover { background: var(--ice-300); border-color: var(--ice-300); color: var(--ink-900); }

.btn--ghost {
  background: rgba(46, 143, 168, 0.08);
  border-color: var(--line-2);
  color: var(--ice-300);
}
.btn--ghost:hover { background: rgba(46, 143, 168, 0.22); border-color: var(--ice-600); color: #FFFFFF; }

.btn--sm { padding: 9px 15px; font-size: 13px; }
.btn--block { width: 100%; }

/* ---------- 08 面板与切角 ---------- */
.cut { clip-path: polygon(12px 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%, 0 12px); }
.cut--lg { clip-path: polygon(22px 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%, 0 22px); }

.panel {
  position: relative;
  padding: clamp(18px, 2.6vw, 30px);
  background: rgba(11, 27, 34, 0.72);
  border: 1px solid var(--line);
  border-radius: 2px;
}
.panel--moss { background: linear-gradient(160deg, var(--moss-600), var(--pine-900)); }
.panel--rail { background: linear-gradient(180deg, rgba(18, 58, 51, 0.9), rgba(11, 27, 34, 0.9)); }
.panel--paper { background: var(--paper-100); border-color: rgba(8, 19, 26, 0.14); color: #17242A; }
.panel--paper .h1, .panel--paper .h2, .panel--paper .h3, .panel--paper .h-display { color: #0B1B22; }
.panel--paper .prose, .panel--paper .lede { color: #22303A; }
.panel--paper a { color: #14606F; }

.band {
  position: relative;
  padding-block: clamp(24px, 3.6vw, 44px);
  background: var(--moss-600);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.band--pine { background: linear-gradient(90deg, var(--pine-900), var(--pine-700)); }
.band--paper { background: var(--paper-100); color: #17242A; border-color: rgba(8, 19, 26, 0.14); }
.band--paper .h2, .band--paper .h1 { color: #0B1B22; }

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

/* ---------- 09 编号与条款 ---------- */
.no-block {
  display: inline-grid;
  place-items: center;
  min-width: 44px;
  padding: 7px 9px;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--ink-900);
  background: var(--ice-300);
  clip-path: polygon(7px 0, 100% 0, 100% calc(100% - 7px), calc(100% - 7px) 100%, 0 100%, 0 7px);
}
.no-block--amber { background: var(--amber-400); }
.no-block--coral { background: var(--coral-500); color: #FFFFFF; }
.no-block--sm { min-width: 34px; padding: 5px 7px; font-size: 12.5px; }

.algo-no {
  font-family: var(--font-mono);
  font-size: clamp(28px, 3.6vw, 44px);
  font-weight: 600;
  line-height: 1;
  color: var(--amber-400);
}

.clause {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 16px;
  padding: 16px 18px;
  background: rgba(11, 27, 34, 0.66);
  border: 1px solid var(--line);
  border-left: 3px solid var(--ice-600);
}
.clause__no {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--ice-300);
  padding-top: 2px;
}
.clause__body { font-size: 15.5px; line-height: 1.75; color: rgba(237, 231, 218, 0.86); }
.clause__body strong { color: var(--paper-100); }
.clause--forbid { border-left-color: var(--coral-500); background: rgba(228, 89, 63, 0.07); }
.clause--forbid .clause__no { color: var(--coral-500); }
.clause--score { border-left-color: var(--amber-400); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  border: 1px solid var(--line-2);
  border-radius: 2px;
  color: var(--ice-300);
}
.tag--amber { color: var(--amber-400); border-color: rgba(232, 177, 74, 0.4); }
.tag--coral { color: var(--coral-500); border-color: rgba(228, 89, 63, 0.45); }
.tag--ghost { color: var(--stone-400); border-color: var(--line); }

/* ---------- 10 索引 / 折叠 / 滑选条 ---------- */
.index-list { display: flex; flex-direction: column; gap: 2px; }

.index-list__item {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 14px;
  align-items: baseline;
  padding: 13px 14px;
  border-top: 1px solid var(--line);
  transition: background var(--t) var(--ease);
}
.index-list__item:last-child { border-bottom: 1px solid var(--line); }
.index-list__item:hover { background: rgba(138, 212, 227, 0.06); }

.index-list__num {
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--amber-400);
}
.index-list__body { font-size: 15.5px; color: rgba(237, 231, 218, 0.86); }
.index-list__meta { font-family: var(--font-mono); font-size: 11.5px; letter-spacing: 0.1em; color: var(--stone-400); }

.accordion { display: flex; flex-direction: column; gap: 2px; }

.accordion__item { border: 1px solid var(--line); background: rgba(11, 27, 34, 0.55); border-radius: 2px; }

.accordion__trigger {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 14px;
  align-items: center;
  width: 100%;
  padding: 15px 16px;
  text-align: left;
  font-size: 15.5px;
  font-weight: 600;
  color: var(--paper-100);
  transition: background var(--t) var(--ease), color var(--t) var(--ease);
}
.accordion__trigger:hover { background: rgba(138, 212, 227, 0.07); }
.accordion__trigger::after {
  content: "";
  width: 9px;
  height: 9px;
  border-right: 1.5px solid var(--ice-300);
  border-bottom: 1.5px solid var(--ice-300);
  transform: rotate(45deg);
  transition: transform var(--t) var(--ease), border-color var(--t) var(--ease);
}
.accordion__trigger[aria-expanded="true"] { background: rgba(46, 143, 168, 0.16); }
.accordion__trigger[aria-expanded="true"]::after { transform: rotate(-135deg); border-color: var(--amber-400); }

.accordion__num {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--ice-300);
}

.accordion__panel { padding: 4px 16px 18px; }
.accordion__panel[hidden] { display: none; }
.accordion__panel .prose { max-width: 44em; font-size: 15.5px; }

.strip {
  display: flex;
  gap: var(--gap);
  overflow-x: auto;
  scroll-snap-type: x proximity;
  padding-bottom: 10px;
  -webkit-overflow-scrolling: touch;
  scrollbar-color: var(--ice-600) transparent;
}
.strip__item { flex: 0 0 clamp(230px, 30vw, 320px); scroll-snap-align: start; }

/* ---------- 11 媒体容器 ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  width: 100%;
  background: linear-gradient(140deg, var(--pine-700), var(--ink-900));
  border: 1px solid var(--line);
  border-radius: 2px;
}
.media img,
.media picture img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 420ms var(--ease);
}
.media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(11, 27, 34, 0) 40%, rgba(11, 27, 34, 0.62) 100%);
}
.media:hover img { transform: scale(1.02); }

.media--21x9 { aspect-ratio: 21 / 9; }
.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--1x1 { aspect-ratio: 1 / 1; }
.media--3x4 { aspect-ratio: 3 / 4; }

.media__badge {
  position: absolute;
  z-index: 2;
  left: 12px;
  top: 12px;
  padding: 5px 9px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--ink-900);
  background: var(--amber-400);
  clip-path: polygon(6px 0, 100% 0, 100% calc(100% - 6px), calc(100% - 6px) 100%, 0 100%, 0 6px);
}
.media__badge--coral { background: var(--coral-500); color: #FFFFFF; }
.media__badge--ice { background: var(--ice-300); }

.media__cap {
  position: absolute;
  z-index: 2;
  left: 14px;
  right: 14px;
  bottom: 12px;
  font-size: 13px;
  line-height: 1.5;
  color: rgba(237, 231, 218, 0.9);
}

/* ---------- 12 容器与网格 ---------- */
.wrap {
  width: 100%;
  max-width: 1180px;
  margin-inline: auto;
  padding-inline: var(--pad);
}
.wrap--wide { max-width: 1400px; }

.section { padding-block: clamp(40px, 6vw, 80px); }
.section--tight { padding-block: clamp(26px, 3.4vw, 46px); }

.section__head { display: flex; flex-direction: column; gap: 12px; margin-bottom: clamp(20px, 3vw, 34px); }

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gap);
}
.grid > * { grid-column: 1 / -1; min-width: 0; }

.stack { display: flex; flex-direction: column; gap: var(--gap); }
.stack--sm { gap: 10px; }
.cluster { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 16px; }

/* ---------- 面包屑 ---------- */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--stone-400);
}
.crumbs__item { color: var(--stone-400); }
.crumbs__item a { color: var(--ice-300); }
.crumbs__sep { color: rgba(141, 154, 153, 0.6); }
.crumbs__item:last-child { color: var(--paper-100); }

/* ---------- 13 工具与动效 ---------- */
.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.has-js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 420ms var(--ease), transform 420ms var(--ease);
}
.has-js [data-reveal].is-visible { opacity: 1; transform: none; }

/* ---------- 14 大屏：左侧常驻轨道 ---------- */
@media (min-width: 1080px) {
  body { padding-left: var(--rail-w); }

  .site-header {
    position: fixed;
    inset: 0 auto 0 0;
    display: flex;
    flex-direction: column;
    width: var(--rail-w);
    overflow-y: auto;
    padding: 30px 24px 22px;
    background: transparent;
    border-right: 1px solid var(--line);
    border-bottom: 0;
    transition: background var(--t) var(--ease), box-shadow var(--t) var(--ease), border-color var(--t) var(--ease);
  }
  .site-header[data-scrolled="true"] {
    background: linear-gradient(180deg, var(--pine-700) 0%, var(--pine-900) 62%, var(--ink-800) 100%);
    border-right-color: transparent;
    box-shadow: 1px 0 0 rgba(138, 212, 227, 0.18), 30px 0 70px -40px rgba(0, 0, 0, 0.95);
  }

  .site-header__bar {
    flex-direction: column;
    align-items: flex-start;
    gap: 18px;
    min-height: 0;
    padding: 0;
    background: none;
    border: 0;
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
  }
  .site-header[data-scrolled="true"] .site-header__bar { background: none; border: 0; }

  .nav-toggle { display: none; }

  .site-nav,
  .site-nav[data-open="false"],
  .site-nav[data-open="true"] {
    position: static;
    inset: auto;
    z-index: auto;
    flex: 1 1 auto;
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding: 0;
    margin-top: 28px;
    overflow: visible;
    background: none;
    border: 0;
    opacity: 1;
    visibility: visible;
    transform: none;
    transition: none;
  }

  .site-nav__link { padding: 10px 30px 10px 10px; font-size: 15px; }

  .site-progress {
    left: auto;
    right: 0;
    bottom: 0;
    top: 0;
    width: 2px;
    height: auto;
    background: rgba(138, 212, 227, 0.1);
  }
  .site-progress__bar {
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, var(--ice-600), var(--amber-400));
    transform: scaleY(var(--p, 0));
    transform-origin: 50% 0;
  }

  .rail-track {
    display: block;
    position: relative;
    height: 26px;
    margin-top: 18px;
  }
  .rail-track span {
    position: absolute;
    left: 0;
    height: 1px;
    transform-origin: 0 50%;
  }
  .rail-track span:nth-child(1) { top: 0; width: 100%; background: linear-gradient(90deg, var(--ice-600), transparent); }
  .rail-track span:nth-child(2) { top: 7px; width: 62%; background: linear-gradient(90deg, var(--amber-400), transparent); opacity: 0.75; }
  .rail-track span:nth-child(3) { top: 14px; width: 38%; background: linear-gradient(90deg, var(--stone-400), transparent); opacity: 0.6; }

  .footer__inner { grid-template-columns: minmax(0, 1.05fr) minmax(0, 1.35fr) minmax(0, 1fr); }
  .footer__cols { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

/* ---------- 15 平板 ---------- */
@media (min-width: 760px) {
  .span-3 { grid-column: span 3; }
  .span-4 { grid-column: span 4; }
  .span-5 { grid-column: span 5; }
  .span-6 { grid-column: span 6; }
  .span-7 { grid-column: span 7; }
  .span-8 { grid-column: span 8; }
  .span-9 { grid-column: span 9; }
  .span-12 { grid-column: span 12; }

  .footer__inner { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer__reach { grid-column: 1 / -1; }
}

/* ---------- 16 手机细节 ---------- */
@media (max-width: 420px) {
  .brand__line { display: none; }
  .footer__base { justify-content: flex-start; }
  .footer__list--plain li { grid-template-columns: 1fr; gap: 2px; }
}

/* ---------- 17 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;
  }
  .has-js [data-reveal] { opacity: 1; transform: none; }
  .btn:hover { transform: none; }
  .media:hover img { transform: none; }
}

@media (min-width: 1080px) {
  html { scroll-behavior: smooth; }
}