/* ============================================================
   球盟会赛场 · 共享样式表 /assets/site.css
   夜墨绿纸场 × 数据屏幕：细线网格、坐标索引、斜切节奏
   ============================================================ */

:root {
  --ink: #071A17;
  --ink-2: #0B2B26;
  --paper: #F2E9D8;
  --sand: #DED0B6;
  --cyan: #3DF2C4;
  --orange: #FF6B3D;
  --violet: #8C5BFF;
  --mist: #9AC9BC;
  --white: #F7FBF8;
  --graphite: #233A34;
  --alert: #E5484D;

  --line: rgba(154, 201, 188, 0.22);
  --line-soft: rgba(154, 201, 188, 0.14);
  --line-paper: rgba(35, 58, 52, 0.18);

  --header-h: 100px;
  --gutter: clamp(18px, 4vw, 56px);
  --maxw: 1280px;

  --font-sans: "Noto Sans SC", system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "IBM Plex Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --dur: 240ms;
}

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--ink);
  color: var(--white);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
h1, h2, h3, h4, p, figure, blockquote, dl, dd { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
img, svg, video { max-width: 100%; display: block; }
a { color: inherit; }
button { font: inherit; color: inherit; }
main { display: block; }
table { border-collapse: collapse; width: 100%; }

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}
.section--paper :focus-visible,
.footer-cta:focus-visible { outline-color: var(--graphite); }
#main-content:focus-visible { outline: 2px solid var(--cyan); outline-offset: -2px; }

/* ---------- 中文排版 ---------- */
h1, h2, h3 { line-height: 1.16; font-weight: 500; letter-spacing: -0.01em; }
p { line-height: 1.78; }
strong { font-weight: 700; }

.display-xl {
  font-size: clamp(56px, 9vw, 160px);
  font-weight: 200;
  letter-spacing: -0.04em;
  line-height: 0.92;
  margin: 0;
}
.display-accent {
  font-style: italic;
  font-weight: 900;
  letter-spacing: -0.03em;
  color: var(--cyan);
}
.lede {
  font-size: clamp(16px, 1.4vw, 18px);
  line-height: 1.75;
  color: var(--mist);
  max-width: 56ch;
}
.section--paper .lede { color: var(--graphite); }
.prose { max-width: 68ch; font-size: 17px; line-height: 1.78; }
.prose > * + * { margin-top: 1em; }

.index-label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
  margin: 0;
}
.index-label::before {
  content: "";
  width: 20px;
  height: 1px;
  background: currentColor;
  flex: none;
}
.section--paper .index-label { color: var(--graphite); }

/* ---------- 布局骨架 ---------- */
.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.page-body { padding-top: calc(var(--header-h) + 28px); }

.section {
  position: relative;
  padding-block: clamp(48px, 7vw, 104px);
}
.section--ink { background: var(--ink); color: var(--white); --line: rgba(154, 201, 188, 0.22); }
.section--ink2 { background: var(--ink-2); color: var(--white); --line: rgba(154, 201, 188, 0.22); }
.section--paper {
  background: var(--paper);
  color: var(--graphite);
  --line: var(--line-paper);
}

.grid { display: grid; gap: clamp(16px, 2.4vw, 32px); }
.grid--7-5 { grid-template-columns: 7fr 5fr; }
.grid--8-4 { grid-template-columns: 8fr 4fr; }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6em;
  padding: 14px 24px;
  border: 1px solid transparent;
  border-radius: 0;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.02em;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 180ms var(--ease), color 180ms var(--ease),
              border-color 180ms var(--ease), transform 180ms var(--ease);
}
.btn--primary {
  background: var(--cyan);
  color: #04120F;
  border-color: var(--cyan);
  font-weight: 700;
}
.btn--primary:hover { background: #6BFFD6; border-color: #6BFFD6; }
.btn--ghost {
  background: transparent;
  color: var(--white);
  border-color: var(--line);
}
.btn--ghost:hover { border-color: var(--cyan); color: var(--cyan); }
.section--paper .btn--ghost { color: var(--graphite); border-color: var(--line-paper); }
.section--paper .btn--ghost:hover { border-color: var(--graphite); color: var(--graphite); }
.btn:active { transform: translateY(1px); }

/* ---------- 卡片 ---------- */
.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 28px);
  border: 1px solid var(--line);
  background: rgba(154, 201, 188, 0.04);
  transition: transform 180ms var(--ease), border-color 180ms var(--ease);
}
.card:hover { transform: translateY(-2px); border-color: var(--cyan); }
.section--paper .card { background: rgba(255, 255, 255, 0.5); }
.card__index {
  display: block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--orange);
}
.card__title {
  font-size: clamp(18px, 1.8vw, 22px);
  font-weight: 700;
  margin: 0.45em 0 0.4em;
  line-height: 1.3;
}
.card__text { font-size: 15px; line-height: 1.7; color: var(--mist); }
.section--paper .card__text { color: var(--graphite); }
.card__meta {
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

/* ---------- 数据块 ---------- */
.stat { display: block; }
.stat__value {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(36px, 6vw, 72px);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}
.stat__label {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--mist);
}

/* ---------- 图像容器（页面阶段放 img） ---------- */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--line);
  background:
    linear-gradient(150deg, var(--ink-2) 0%, var(--ink) 58%, #0F3B33 100%);
  isolation: isolate;
}
.media-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  background-image:
    linear-gradient(rgba(154, 201, 188, 0.10) 1px, transparent 1px),
    linear-gradient(90deg, rgba(154, 201, 188, 0.10) 1px, transparent 1px);
  background-size: 40px 40px;
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  background:
    radial-gradient(120% 90% at 82% 8%, rgba(61, 242, 196, 0.22), transparent 62%),
    radial-gradient(90% 70% at 8% 92%, rgba(140, 91, 255, 0.20), transparent 62%);
}
.media-frame img {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
@media (max-width: 640px) {
  .media-frame, .media-frame--wide { aspect-ratio: 4 / 3; }
}

/* ---------- 标签页 ---------- */
.tabs { display: block; }
.tab-list {
  display: flex;
  flex-wrap: wrap;
  gap: 2px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 22px;
}
.tab {
  appearance: none;
  background: transparent;
  border: 0;
  border-bottom: 2px solid transparent;
  padding: 11px 16px;
  font-size: 14px;
  letter-spacing: 0.02em;
  color: var(--mist);
  cursor: pointer;
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}
.tab:hover { color: var(--white); }
.section--paper .tab { color: var(--graphite); }
.section--paper .tab:hover { color: var(--ink); }
.tab[aria-selected="true"] {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}
.section--paper .tab[aria-selected="true"] { color: var(--graphite); border-bottom-color: var(--ink); }
.tab-panel[hidden] { display: none; }

/* ---------- 折叠面板 ---------- */
.accordion { border-top: 1px solid var(--line); }
.accordion__item { border-bottom: 1px solid var(--line); }
.accordion__summary {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 0;
  cursor: pointer;
  list-style: none;
  font-weight: 500;
  font-size: 16px;
}
.accordion__summary::-webkit-details-marker { display: none; }
.accordion__summary::after {
  content: "+";
  font-family: var(--font-mono);
  color: var(--cyan);
  font-size: 16px;
  flex: none;
}
.accordion__item[open] > .accordion__summary::after { content: "–"; }
.accordion__body {
  padding: 0 0 18px;
  font-size: 15px;
  line-height: 1.78;
  color: var(--mist);
}
.section--paper .accordion__body { color: var(--graphite); }

/* ---------- 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--mist);
}
.breadcrumb li { display: inline-flex; align-items: center; gap: 8px; }
.breadcrumb li + li::before { content: "/"; color: rgba(154, 201, 188, 0.5); }
.breadcrumb a { text-decoration: none; border-bottom: 1px solid transparent; }
.breadcrumb a:hover { color: var(--cyan); border-bottom-color: currentColor; }
.breadcrumb [aria-current="page"] { color: var(--white); }
.section--paper .breadcrumb { color: var(--graphite); }
.section--paper .breadcrumb [aria-current="page"] { color: var(--ink); }

/* ---------- 显现 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease);
}
.reveal.is-visible { opacity: 1; transform: none; }

/* ============================================================
   头部
   ============================================================ */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 300;
  padding: 11px 18px;
  background: var(--cyan);
  color: #04120F;
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  transform: translateY(-180%);
  transition: transform 180ms var(--ease);
}
.skip-link:focus,
.skip-link:focus-visible { transform: none; }

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  color: var(--white);
  background: linear-gradient(
    180deg,
    rgba(7, 26, 23, 0.94) 0%,
    rgba(7, 26, 23, 0.62) 62%,
    rgba(7, 26, 23, 0) 100%
  );
  transition: background-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}
.site-header.is-scrolled {
  background-color: var(--ink-2);
  background-image: none;
  box-shadow: 0 1px 0 rgba(61, 242, 196, 0.28), 0 22px 44px -34px rgba(0, 0, 0, 0.95);
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  z-index: 140;
  background: linear-gradient(90deg, var(--cyan) 0%, var(--violet) 100%);
  transform: scaleX(var(--progress, 0));
  transform-origin: 0 50%;
  pointer-events: none;
}

/* 速查条 */
.utility-bar {
  border-bottom: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
}
.utility-inner {
  display: flex;
  align-items: center;
  gap: 16px;
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding: 6px var(--gutter);
}
.utility-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--cyan);
  text-transform: uppercase;
  flex: none;
}
.utility-label::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--orange);
  display: block;
  flex: none;
}
.utility-list { display: flex; align-items: center; }
.utility-link {
  display: inline-block;
  padding: 2px 12px;
  color: var(--mist);
  text-decoration: none;
  border-left: 1px solid var(--line-soft);
  transition: color 160ms var(--ease);
}
.utility-link:hover { color: var(--white); }
.utility-cta {
  margin-left: auto;
  color: var(--cyan);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: 1px solid rgba(61, 242, 196, 0.42);
  white-space: nowrap;
}
.utility-cta:hover { border-bottom-color: var(--cyan); }

/* 品牌 + 导航 */
.header-main {
  display: flex;
  align-items: center;
  gap: 20px;
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding: 14px var(--gutter) 16px;
  transition: padding var(--dur) var(--ease);
}
.site-header.is-scrolled .header-main { padding-block: 8px; }

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--white);
  flex: none;
}
.brand-mark {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--cyan);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 16px;
  line-height: 1;
  transform: rotate(-3.5deg);
  flex: none;
}
.brand-text { display: block; }
.brand-name {
  display: block;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.2;
}
.brand-sub {
  display: block;
  margin-top: 3px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  color: var(--mist);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  margin-left: auto;
  padding: 9px 13px;
  background: transparent;
  border: 1px solid rgba(154, 201, 188, 0.36);
  color: var(--white);
  font-size: 13px;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: border-color 160ms var(--ease), color 160ms var(--ease);
}
.nav-toggle:hover { border-color: var(--cyan); color: var(--cyan); }
.nav-toggle-lines {
  position: relative;
  display: block;
  width: 20px;
  height: 2px;
  background: currentColor;
  transition: background-color 160ms var(--ease);
}
.nav-toggle-lines::before,
.nav-toggle-lines::after {
  content: "";
  position: absolute;
  left: 0;
  width: 20px;
  height: 2px;
  background: currentColor;
  transition: transform 180ms var(--ease), top 180ms var(--ease);
}
.nav-toggle-lines::before { top: -6px; }
.nav-toggle-lines::after { top: 6px; }
.site-header[data-open="true"] .nav-toggle-lines { background: transparent; }
.site-header[data-open="true"] .nav-toggle-lines::before { top: 0; transform: rotate(45deg); }
.site-header[data-open="true"] .nav-toggle-lines::after { top: 0; transform: rotate(-45deg); }
.nav-toggle-label { line-height: 1; }

.primary-nav {
  display: flex;
  align-items: center;
  gap: 22px;
  margin-left: auto;
}
.nav-list { display: flex; align-items: center; gap: 2px; }
.nav-link {
  position: relative;
  display: inline-block;
  padding: 9px 12px;
  font-size: 14.5px;
  letter-spacing: 0.02em;
  color: var(--mist);
  text-decoration: none;
  transition: color 160ms var(--ease);
}
.nav-link::after {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 2px;
  height: 1px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 180ms var(--ease);
}
.nav-link:hover { color: var(--white); }
.nav-link:hover::after { transform: scaleX(1); }
.nav-link[aria-current="page"] { color: var(--white); }
.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--orange);
  height: 2px;
}
.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  padding: 10px 18px;
  background: var(--cyan);
  color: #04120F;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-decoration: none;
  border: 1px solid var(--cyan);
  transition: background-color 160ms var(--ease), border-color 160ms var(--ease);
}
.nav-cta:hover { background: #6BFFD6; border-color: #6BFFD6; }

/* 侧边悬浮通道 */
.side-rail {
  position: fixed;
  top: 50%;
  right: 14px;
  z-index: 90;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 12px 7px;
  background: rgba(11, 43, 38, 0.88);
  border: 1px solid var(--line);
  box-shadow: 0 18px 40px -30px rgba(0, 0, 0, 0.9);
}
.side-rail-tag {
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.32em;
  color: var(--orange);
}
.side-rail-list { display: grid; gap: 2px; }
.side-rail-link {
  writing-mode: vertical-rl;
  padding: 8px 3px;
  font-size: 12.5px;
  letter-spacing: 0.16em;
  color: var(--mist);
  text-decoration: none;
  border-left: 1px solid transparent;
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}
.side-rail-link:hover { color: var(--cyan); border-left-color: var(--cyan); }

/* ============================================================
   页脚
   ============================================================ */
.site-footer {
  position: relative;
  background: var(--ink);
  color: var(--white);
  border-top: 1px solid rgba(61, 242, 196, 0.24);
  overflow: hidden;
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(154, 201, 188, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(154, 201, 188, 0.07) 1px, transparent 1px);
  background-size: 64px 64px;
  pointer-events: none;
}
.footer-inner {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding: clamp(40px, 6vw, 80px) var(--gutter) 26px;
}
.footer-top {
  display: grid;
  grid-template-columns: minmax(240px, 1.15fr) minmax(240px, 1.35fr);
  gap: clamp(28px, 5vw, 64px);
  padding-bottom: 34px;
  border-bottom: 1px solid var(--line-soft);
}
.footer-brand { display: grid; gap: 10px; justify-items: start; }
.footer-mark {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border: 1px solid var(--cyan);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 14px;
  transform: rotate(3.5deg);
}
.footer-title {
  font-size: clamp(20px, 2.2vw, 26px);
  font-weight: 700;
  letter-spacing: 0.03em;
  line-height: 1.25;
}
.footer-note {
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--mist);
  max-width: 34ch;
}
.footer-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  margin-top: 4px;
  padding-bottom: 3px;
  font-size: 14.5px;
  font-weight: 500;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(61, 242, 196, 0.42);
  transition: border-color 160ms var(--ease), color 160ms var(--ease);
}
.footer-cta::after { content: "→"; font-family: var(--font-mono); }
.footer-cta:hover { color: #6BFFD6; border-bottom-color: #6BFFD6; }

.footer-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px 28px;
}
.footer-col-title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--orange);
}
.footer-list { display: grid; gap: 9px; }
.footer-link {
  font-size: 14.5px;
  color: var(--mist);
  text-decoration: none;
  transition: color 160ms var(--ease);
}
.footer-link:hover { color: var(--white); }

.footer-contact {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px 32px;
  margin-top: 30px;
  padding-top: 26px;
  border-top: 1px solid var(--line-soft);
}
.contact-item { display: flex; flex-direction: column; gap: 5px; }
.contact-label {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist);
}
.contact-value {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--white);
  word-break: break-word;
}
.copy-btn {
  padding: 3px 9px;
  background: transparent;
  border: 1px solid rgba(154, 201, 188, 0.34);
  color: var(--mist);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}
.copy-btn:hover { color: var(--cyan); border-color: var(--cyan); }
.copy-btn.is-copied { color: #04120F; background: var(--cyan); border-color: var(--cyan); }

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px 24px;
  margin-top: 30px;
  padding-top: 20px;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--mist);
}
.footer-legal, .footer-meta { margin: 0; }
.footer-meta { color: rgba(154, 201, 188, 0.7); }

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1200px) {
  .side-rail { display: none; }
  .primary-nav { gap: 12px; }
  .nav-link { padding-inline: 9px; font-size: 14px; }
  .nav-link::after { left: 9px; right: 9px; }
}

@media (max-width: 1080px) {
  .grid--7-5, .grid--8-4 { grid-template-columns: 1fr; }
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 900px) {
  :root { --header-h: 94px; }

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

  .primary-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    z-index: 95;
    display: grid;
    gap: 0;
    margin-left: 0;
    padding: 6px var(--gutter) 24px;
    background: var(--ink-2);
    border-top: 1px solid var(--line);
    border-bottom: 1px solid rgba(61, 242, 196, 0.28);
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-6px);
    transition: max-height var(--dur) var(--ease), opacity 180ms var(--ease),
                transform 180ms var(--ease), visibility var(--dur) linear;
  }
  .site-header[data-open="true"] .primary-nav {
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
    opacity: 1;
    visibility: visible;
    transform: none;
  }
  .nav-list { display: grid; gap: 0; width: 100%; }
  .nav-link {
    display: block;
    padding: 14px 0;
    font-size: 16px;
    color: var(--white);
    border-bottom: 1px solid var(--line-soft);
  }
  .nav-link::after { display: none; }
  .nav-link[aria-current="page"] { color: var(--cyan); }
  .nav-link[aria-current="page"]::before {
    content: "▍";
    color: var(--orange);
    margin-right: 6px;
  }
  .nav-cta {
    width: 100%;
    justify-content: center;
    margin-top: 18px;
    padding-block: 13px;
  }

  .grid--3 { grid-template-columns: 1fr; }
  .footer-top { grid-template-columns: 1fr; }
  .brand-sub { display: none; }
}

@media (max-width: 720px) {
  .utility-list { display: none; }
  .utility-inner { justify-content: space-between; gap: 10px; }
  .utility-label { font-size: 10.5px; letter-spacing: 0.1em; }
  .utility-cta { font-size: 10.5px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-bottom { flex-direction: column; }
}

@media (max-width: 520px) {
  .grid--4 { grid-template-columns: 1fr; }
  .utility-label::before { display: none; }
  .card { padding: 18px; }
}

/* ============================================================
   动效偏好
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .reveal { opacity: 1; transform: none; }
  .card:hover { transform: none; }
  .btn:active { transform: none; }
  .scroll-progress { transition: none; }
}