/* ==========================================================================
   HAIOU 海鸥体育 · 共享样式表  /assets/site.css
   内容：重置 / 设计变量 / 中文排版 / 命令栏头部 / 四列页脚 / 通用组件
   页面特色布局请写入页面专属 CSS，不要覆盖本文件的变量语义
   ========================================================================== */

/* ---------- 1. 重置 ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--haiou-white);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.8;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
table { border-collapse: collapse; border-spacing: 0; }
main { display: block; }

/* ---------- 2. 设计变量 ---------- */
:root {
  /* 色彩 */
  --haiou-white: #F7FAFC;
  --deep-sea: #062A4A;
  --voyage-blue: #0E5A8A;
  --wave-teal: #1FB6C1;
  --pale-teal: #D8F1F4;
  --wing-orange: #FF7A2F;
  --orange-ink: #B24A0E;
  --signal-red: #E03A3E;
  --tide-gray: #7C96A8;
  --ink: #0A171F;
  --mist-white: #FFFFFF;

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

  /* 尺度 */
  --maxw: 1280px;
  --gutter: clamp(20px, 4.5vw, 64px);
  --bar-h: 84px;
  --bar-h-min: 44px;
  --cut: 22px;
  --hairline: rgba(124, 150, 168, .34);
  --hairline-teal: rgba(31, 182, 193, .38);
  --ease: cubic-bezier(.22, .61, .36, 1);

  /* 由 JS 写入的滚动位移，供轨迹线使用 */
  --scroll-y: 0px;
}

@media (max-width: 1080px) {
  :root { --bar-h: 76px; --bar-h-min: 42px; }
}
@media (max-width: 720px) {
  :root { --bar-h: 64px; --bar-h-min: 40px; --cut: 18px; }
}

/* ---------- 3. 中文排版基线 ---------- */
p { max-width: 42em; }

strong, b { font-weight: 700; }

::selection {
  background: var(--wave-teal);
  color: var(--deep-sea);
}

:focus-visible {
  outline: 2px solid var(--wing-orange);
  outline-offset: 3px;
  border-radius: 2px;
}

#main-content {
  scroll-margin-top: calc(var(--bar-h-min) + 14px);
}

/* ---------- 4. 跳至主要内容 ---------- */
.skip-link {
  position: fixed;
  top: -140px;
  left: 16px;
  z-index: 300;
  padding: 12px 20px;
  background: var(--wing-orange);
  color: var(--ink);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .02em;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 0 100%);
  transition: top .2s var(--ease);
}
.skip-link:focus { top: 14px; }

/* ---------- 5. 命令栏头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  background:
    linear-gradient(104deg,
      var(--deep-sea) 0%,
      var(--deep-sea) 48%,
      #0B4470 78%,
      var(--voyage-blue) 100%);
  color: var(--haiou-white);
  border-bottom: 1px solid var(--hairline-teal);
}

.site-header::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: min(38%, 460px);
  background: linear-gradient(104deg, rgba(31, 182, 193, .22), rgba(31, 182, 193, 0) 72%);
  pointer-events: none;
}

.cmd-bar {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: clamp(14px, 2.4vw, 34px);
  width: min(100% - (var(--gutter) * 2), var(--maxw));
  height: var(--bar-h);
  margin-inline: auto;
  transition: height .28s var(--ease);
}

.site-header.is-condensed .cmd-bar { height: var(--bar-h-min); }

/* 品牌 */
.brand {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 4px 0;
}

.brand-mark {
  flex: 0 0 auto;
  width: 30px;
  height: 30px;
  background: linear-gradient(140deg, var(--wave-teal) 0%, var(--wing-orange) 100%);
  clip-path: polygon(0 100%, 50% 0, 100% 100%, 78% 100%, 50% 46%, 22% 100%);
  transition: transform .24s var(--ease);
}
.brand:hover .brand-mark { transform: translateY(-3px); }

.brand-text { display: grid; gap: 2px; }

.brand-name {
  font-size: 18px;
  font-weight: 900;
  line-height: 1;
  letter-spacing: .18em;
  color: var(--mist-white);
}

.brand-sub {
  font-family: var(--font-mono);
  font-size: 10.5px;
  line-height: 1.2;
  letter-spacing: .1em;
  color: rgba(247, 250, 252, .62);
  transition: opacity .2s var(--ease);
}

.site-header.is-condensed .brand-sub { opacity: 0; }

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  padding: 9px 12px;
  border: 1px solid var(--hairline-teal);
  color: var(--haiou-white);
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: .1em;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}
.nav-toggle:hover { color: var(--wing-orange); border-color: var(--wing-orange); }

.nav-toggle-bars { display: grid; gap: 4px; width: 18px; }
.nav-toggle-bars i {
  display: block;
  height: 2px;
  background: currentColor;
  transition: transform .22s var(--ease), opacity .18s var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars i:nth-child(1) { transform: translateY(6px) 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(-6px) rotate(-45deg); }

.nav-toggle-label { white-space: nowrap; }

/* 栏目索引 */
.site-nav { flex: 1 1 auto; display: flex; justify-content: center; min-width: 0; }

.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(4px, 1.5vw, 22px);
}

.nav-item { display: flex; }

.nav-link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: .5em;
  padding: 8px 2px 9px;
  font-size: clamp(13px, 1.02vw, 15px);
  color: rgba(247, 250, 252, .8);
  white-space: nowrap;
  transition: color .2s var(--ease);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 2px;
  bottom: 2px;
  width: 0;
  height: 2px;
  background: var(--wing-orange);
  transition: width .25s var(--ease);
}

.nav-link:hover { color: var(--mist-white); }
.nav-link:hover::after { width: 100%; }

.nav-num {
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 500;
  letter-spacing: .06em;
  color: rgba(247, 250, 252, .5);
  transition: color .2s var(--ease);
}

.nav-link[aria-current="page"] { color: var(--wing-orange); }
.nav-link[aria-current="page"]::after { width: 22px; }
.nav-link[aria-current="page"]:hover::after { width: 22px; }
.nav-link[aria-current="page"] .nav-num { color: var(--wing-orange); }

/* 状态提示与主行动 */
.cmd-meta {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 14px;
}

.status-hint {
  display: inline-flex;
  align-items: center;
  gap: .55em;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .09em;
  color: rgba(247, 250, 252, .72);
  white-space: nowrap;
}

.status-hint::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--wave-teal);
  box-shadow: 0 0 0 3px rgba(31, 182, 193, .18);
}

/* 滚动进度 */
.scroll-progress {
  display: block;
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 2px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--wave-teal) 0%, var(--wing-orange) 100%);
  transition: transform .1s linear;
  pointer-events: none;
}

/* ---------- 6. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 8vw, 110px);
  padding: clamp(48px, 7vw, 88px) 0 28px;
  background: linear-gradient(160deg, var(--deep-sea) 0%, #072F52 46%, var(--voyage-blue) 100%);
  color: rgba(247, 250, 252, .85);
  border-top: 3px solid var(--wave-teal);
}

.footer-inner {
  width: min(100% - (var(--gutter) * 2), var(--maxw));
  margin-inline: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.3fr;
  gap: clamp(22px, 3vw, 48px);
}

.footer-col {
  padding-left: clamp(0px, 1.8vw, 28px);
  border-left: 1px solid rgba(31, 182, 193, .26);
}
.footer-col--brand { padding-left: 0; border-left: 0; }

.footer-brand {
  display: flex;
  align-items: baseline;
  gap: .5em;
  max-width: none;
  font-size: 22px;
  font-weight: 900;
  letter-spacing: .16em;
  line-height: 1.1;
  color: var(--mist-white);
}

.footer-brand-cn {
  font-size: 13.5px;
  font-weight: 700;
  letter-spacing: .1em;
  color: var(--wave-teal);
}

.footer-claim {
  margin-top: 14px;
  max-width: 24em;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(247, 250, 252, .7);
}

.footer-stamp {
  margin-top: 16px;
  max-width: none;
  font-size: 11.5px;
  letter-spacing: .14em;
  color: var(--wing-orange);
}

.footer-title {
  position: relative;
  margin-bottom: 16px;
  padding-left: 12px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .14em;
  color: var(--mist-white);
}
.footer-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: .28em;
  width: 3px;
  height: .9em;
  background: var(--wave-teal);
}

.footer-links { display: grid; gap: 9px; }

.footer-links a {
  display: inline-block;
  font-size: 14px;
  color: rgba(247, 250, 252, .78);
  transition: color .2s var(--ease), transform .2s var(--ease);
}
.footer-links a:hover { color: var(--wing-orange); transform: translateX(4px); }

.footer-text {
  max-width: 22em;
  font-size: 13.5px;
  line-height: 1.75;
  color: rgba(247, 250, 252, .68);
}
.footer-text + .footer-text { margin-top: 8px; }

.footer-contact {
  max-width: none;
  margin-top: 10px;
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--mist-white);
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px 28px;
  margin-top: clamp(36px, 5vw, 64px);
  padding-top: 20px;
  border-top: 1px solid rgba(31, 182, 193, .26);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: rgba(247, 250, 252, .6);
}

.footer-legal { max-width: none; }
.footer-copy { max-width: none; color: rgba(247, 250, 252, .78); }

/* ---------- 7. 通用布局件 ---------- */
.shell {
  width: min(100% - (var(--gutter) * 2), var(--maxw));
  margin-inline: auto;
}

.section { padding-block: clamp(52px, 8vw, 124px); }
.section--tint { background: var(--pale-teal); }
.section--deep {
  background: linear-gradient(120deg, var(--deep-sea), var(--voyage-blue));
  color: var(--haiou-white);
}
.section--deep .lede { color: rgba(247, 250, 252, .78); }
.section--deep .sec-title { color: var(--mist-white); }

.grid { display: grid; gap: clamp(20px, 3vw, 44px); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--sidebar { grid-template-columns: minmax(180px, 236px) minmax(0, 1fr); gap: clamp(24px, 4vw, 68px); }

@media (max-width: 899px) {
  .grid--2, .grid--3, .grid--sidebar { grid-template-columns: minmax(0, 1fr); }
}

/* 切角面板 */
.panel {
  position: relative;
  padding: clamp(20px, 3vw, 36px);
  background: var(--mist-white);
  border: 1px solid var(--hairline);
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, 0 100%);
}
.panel--deep {
  background: linear-gradient(140deg, var(--deep-sea), #0B4772);
  border-color: var(--hairline-teal);
  color: var(--haiou-white);
}
.panel--pale {
  background: var(--pale-teal);
  border-color: var(--hairline-teal);
}
.panel--plain {
  padding: 0;
  background: none;
  border: 0;
  clip-path: none;
}

/* 图片容器基础件 */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: linear-gradient(135deg, var(--pale-teal) 0%, #E9F4F8 58%, var(--mist-white) 100%);
  border: 1px solid var(--hairline);
  clip-path: polygon(0 0, calc(100% - 26px) 0, 100% 26px, 100% 100%, 0 100%);
}
.media-frame > img {
  width: 100%;
  height: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}
.media-frame--wide > img { aspect-ratio: 21 / 9; }
.media-frame--tall > img { aspect-ratio: 4 / 5; }

.media-frame::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 3px;
  background: linear-gradient(90deg, var(--wave-teal) 0%, var(--wing-orange) 100%);
  opacity: .85;
  pointer-events: none;
}

.media-frame__caption {
  margin-top: 10px;
  max-width: 40em;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--tide-gray);
}

/* ---------- 8. 通用排版件 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: .6em;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--voyage-blue);
}
.eyebrow::before {
  content: "";
  width: 26px;
  height: 2px;
  background: var(--wave-teal);
}

.sec-title {
  position: relative;
  padding-left: 18px;
  max-width: 22em;
  font-size: clamp(23px, 3.1vw, 38px);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: .01em;
  color: var(--deep-sea);
}
.sec-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: .2em;
  width: 4px;
  height: .92em;
  background: var(--wave-teal);
}

.lede {
  max-width: 34em;
  font-size: clamp(16.5px, 1.5vw, 20px);
  line-height: 1.72;
  color: #22414F;
}

.mono,
[data-count] {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
}

.prose { max-width: 72ch; }
.prose > * + * { margin-top: 1.15em; }
.prose h2 {
  position: relative;
  padding-left: 18px;
  font-size: clamp(20px, 2.2vw, 26px);
  font-weight: 800;
  line-height: 1.35;
  color: var(--deep-sea);
}
.prose h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: .2em;
  width: 4px;
  height: .9em;
  background: var(--wave-teal);
}
.prose h3 { font-size: 18px; font-weight: 700; color: var(--deep-sea); }
.prose li { position: relative; padding-left: 20px; }
.prose li + li { margin-top: .5em; }
.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 9px;
  height: 2px;
  background: var(--wave-teal);
}
.prose a {
  color: var(--voyage-blue);
  border-bottom: 1px solid rgba(14, 90, 138, .42);
  transition: color .2s var(--ease), border-color .2s var(--ease);
}
.prose a:hover { color: var(--wing-orange); border-color: var(--wing-orange); }

/* ---------- 9. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5em;
  padding: .68em 1.15em;
  font-size: 15px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: .02em;
  white-space: nowrap;
  color: var(--deep-sea);
  background: transparent;
  border: 1.5px solid var(--deep-sea);
  clip-path: polygon(0 0, calc(100% - 11px) 0, 100% 11px, 100% 100%, 0 100%);
  transition: transform .22s var(--ease), background-color .22s var(--ease),
              color .22s var(--ease), border-color .22s var(--ease);
}
.btn:hover { transform: translateX(-6px); border-color: var(--wing-orange); }
.btn:active { border-color: var(--signal-red); color: var(--signal-red); }

.btn--solid {
  background: var(--deep-sea);
  border-color: var(--deep-sea);
  color: var(--haiou-white);
}
.btn--solid:hover {
  background: var(--wing-orange);
  border-color: var(--wing-orange);
  color: var(--ink);
}

.btn--ghost {
  color: var(--voyage-blue);
  border-color: var(--voyage-blue);
}
.btn--ghost:hover { color: var(--wing-orange); background: rgba(255, 122, 47, .08); }

.btn--cta {
  color: var(--wing-orange);
  border-color: var(--wing-orange);
  background: rgba(255, 122, 47, .06);
}
.btn--cta:hover {
  background: var(--wing-orange);
  border-color: var(--wing-orange);
  color: var(--ink);
}

/* ---------- 10. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--tide-gray);
}
.breadcrumb ol { display: flex; flex-wrap: wrap; align-items: center; }
.breadcrumb li + li::before {
  content: "/";
  margin: 0 .7em;
  color: var(--tide-gray);
}
.breadcrumb a {
  color: var(--voyage-blue);
  transition: color .2s var(--ease);
}
.breadcrumb a:hover { color: var(--wing-orange); }

/* ---------- 11. 粘性窄栏索引 ---------- */
.side-index {
  position: sticky;
  top: calc(var(--bar-h-min) + 24px);
  align-self: start;
  display: grid;
  gap: 2px;
  padding-left: 1px;
  border-left: 1px solid var(--hairline);
}

.side-index__link {
  position: relative;
  display: block;
  padding: 8px 14px;
  font-size: 14px;
  color: var(--voyage-blue);
  transition: color .2s var(--ease), transform .2s var(--ease);
}
.side-index__link::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 14px;
  width: 0;
  height: 2px;
  background: var(--wing-orange);
  transition: width .22s var(--ease);
}
.side-index__link:hover { color: var(--wing-orange); transform: translateX(4px); }
.side-index__link[aria-current="true"] { color: var(--ink); font-weight: 600; }
.side-index__link[aria-current="true"]::before { width: 16px; }

/* ---------- 12. 折叠区 ---------- */
.fold { border-top: 1px solid var(--hairline); }
.fold:last-of-type { border-bottom: 1px solid var(--hairline); }

.fold summary {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 18px 0;
  font-size: 16.5px;
  font-weight: 600;
  line-height: 1.6;
  color: var(--deep-sea);
  cursor: pointer;
  list-style: none;
  transition: color .2s var(--ease);
}
.fold summary::-webkit-details-marker { display: none; }
.fold summary::before {
  content: "";
  flex: 0 0 auto;
  margin-top: .55em;
  border-left: 6px solid var(--wave-teal);
  border-top: 5px solid transparent;
  border-bottom: 5px solid transparent;
  transition: transform .2s var(--ease);
}
.fold[open] summary::before { transform: rotate(90deg); }
.fold summary:hover { color: var(--voyage-blue); }

.fold__body {
  padding: 0 0 22px 20px;
  max-width: 70ch;
  font-size: 15.5px;
  line-height: 1.8;
  color: #2B4351;
}

/* ---------- 13. 对照表 ---------- */
.spec-table {
  width: 100%;
  font-size: 15px;
  text-align: left;
}
.spec-table th,
.spec-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--hairline);
  vertical-align: top;
}
.spec-table thead th {
  background: var(--pale-teal);
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: .08em;
  color: var(--voyage-blue);
  white-space: nowrap;
}
.spec-table tbody tr:nth-child(even) { background: rgba(216, 241, 244, .42); }
.spec-table td:first-child { color: var(--deep-sea); font-weight: 600; }

/* ---------- 14. 状态标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: .4em;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  border: 1px solid var(--wave-teal);
  color: var(--voyage-blue);
  white-space: nowrap;
}
.tag--good { border-color: var(--wing-orange); color: var(--orange-ink); }
.tag--warn { border-color: var(--signal-red); color: var(--signal-red); }

/* ---------- 15. 分隔线 ---------- */
.wave-rule {
  display: block;
  width: 100%;
  height: 2px;
  border: 0;
  background: linear-gradient(90deg, var(--wave-teal) 0%, rgba(31, 182, 193, .12) 56%, var(--wing-orange) 100%);
}

.wave-rule--drift {
  height: 3px;
  background-image: repeating-linear-gradient(90deg,
    var(--wave-teal) 0 26px,
    rgba(31, 182, 193, .12) 26px 52px);
  background-size: 52px 100%;
  background-position-x: calc(var(--scroll-y) * -0.25);
}

/* ---------- 16. 显现与计数 ---------- */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .52s var(--ease), transform .52s var(--ease);
}
html.js [data-reveal].is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 17. 响应式：头部 ---------- */
@media (max-width: 1200px) {
  .status-hint { display: none; }
}

@media (max-width: 959px) {
  .nav-toggle { display: inline-flex; }
  .cmd-bar { justify-content: space-between; gap: 12px; }
  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    justify-content: flex-start;
    background: linear-gradient(180deg, var(--deep-sea) 0%, var(--voyage-blue) 100%);
    border-top: 1px solid var(--hairline-teal);
    border-bottom: 1px solid var(--hairline-teal);
    max-height: calc(100vh - var(--bar-h));
    overflow-y: auto;
  }
  .site-nav[data-open] {
    display: block;
    animation: nav-drop .22s var(--ease) both;
  }
  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 8px var(--gutter) 20px;
  }
  .nav-link {
    width: 100%;
    padding: 15px 0;
    font-size: 17px;
    border-bottom: 1px solid rgba(247, 250, 252, .12);
  }
  .nav-link::after { left: 0; bottom: -1px; }
  .nav-link:hover::after { width: 34px; }
  .nav-num { font-size: 12px; }
  .brand-sub { display: none; }
}

@keyframes nav-drop {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: none; }
}

@media (max-width: 620px) {
  .brand-name { font-size: 16px; letter-spacing: .14em; }
  .brand-mark { width: 26px; height: 26px; }
  .btn--cta { padding: .58em .85em; font-size: 13.5px; }
  .cmd-meta { gap: 8px; }
}

/* ---------- 18. 响应式：页脚 ---------- */
@media (max-width: 900px) {
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-col { padding-left: 0; }
  .footer-col--brand { grid-column: 1 / -1; }
}

@media (max-width: 560px) {
  .footer-grid { grid-template-columns: minmax(0, 1fr); gap: 30px; }
  .footer-col { padding-top: 24px; border-top: 1px solid rgba(31, 182, 193, .22); }
  .footer-col--brand { padding-top: 0; border-top: 0; }
  .footer-base { flex-direction: column; }
}

/* ---------- 19. 减弱动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }

  html.js [data-reveal] { opacity: 1; transform: none; }
  .wave-rule--drift { background-position-x: 0; }
  .btn:hover { transform: none; }
  .footer-links a:hover { transform: none; }
  .side-index__link:hover { transform: none; }
}