/* =====================================================================
   GOGO赛场 · /assets/site.css
   共享外壳：reset / tokens / 中文排版 / 头部轨道 / 页脚 / 基础组件
   ===================================================================== */

/* ---------- 1. reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:72px}
body,h1,h2,h3,h4,h5,h6,p,ul,ol,li,figure,blockquote,dl,dd{margin:0;padding:0}
ul,ol{list-style:none}
img,picture,svg,video{display:block;max-width:100%}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;cursor:pointer}
a{color:inherit;text-decoration:none}
table{border-collapse:collapse;width:100%}
:focus-visible{outline:2px solid var(--cyan);outline-offset:3px;border-radius:4px}

/* ---------- 2. tokens ---------- */
:root{
  --ink:#06110F;
  --panel:#0B1F1B;
  --panel-2:#12332C;
  --cyan:#35F0D0;
  --cyan-soft:#7FF7E4;
  --orange:#FF8A3D;
  --amber:#FFC24B;
  --white:#E9F5F1;
  --muted:#9DB8B1;
  --line:#2C4A43;
  --rail:88px;
  --maxw:1360px;
  --textw:720px;
  --r-lg:28px;
  --r-md:16px;
  --r-sm:4px;
  --font-sans:system-ui,-apple-system,"PingFang SC","Microsoft YaHei","Noto Sans SC",sans-serif;
  --font-mono:ui-monospace,"SFMono-Regular",Consolas,"Liberation Mono",monospace;
}

/* ---------- 3. 基底与中文排版 ---------- */
body{
  background-color:var(--ink);
  color:var(--white);
  font-family:var(--font-sans);
  font-size:16px;
  line-height:1.75;
  letter-spacing:.01em;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
body::before{
  content:"";position:fixed;inset:0;z-index:0;pointer-events:none;
  background:
    radial-gradient(900px 520px at 84% -8%,rgba(53,240,208,.10),transparent 62%),
    radial-gradient(700px 420px at 4% 6%,rgba(255,138,61,.07),transparent 60%),
    repeating-linear-gradient(0deg,rgba(233,245,241,.025) 0 1px,transparent 1px 5px);
}
#main-content{position:relative;z-index:1;display:block}
html.nav-open,html.nav-open body{overflow:hidden}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}

/* ---------- 4. 布局容器与网格 ---------- */
.container{width:100%;max-width:var(--maxw);margin-inline:auto;padding-inline:clamp(18px,4vw,40px)}
.section{position:relative;padding-block:clamp(56px,8vw,116px)}
.section--tight{padding-block:clamp(34px,5vw,62px)}
.section--panel{background:var(--panel);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.grid-12{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:clamp(16px,2vw,28px)}
.col-3{grid-column:span 3}
.col-4{grid-column:span 4}
.col-5{grid-column:span 5}
.col-6{grid-column:span 6}
.col-7{grid-column:span 7}
.col-8{grid-column:span 8}
.col-12{grid-column:span 12}
.prose{max-width:var(--textw);font-size:16px;line-height:1.85;color:#D6E8E3}
.prose p + p{margin-top:1.05em}
.prose h2{margin-top:1.5em;font-size:clamp(21px,2.4vw,26px);font-weight:800;color:var(--white);letter-spacing:-.01em}
.prose h3{margin-top:1.2em;font-size:18px;font-weight:700;color:var(--white)}
.prose ul{margin-top:.7em;padding-left:1.1em;list-style:disc;display:flex;flex-direction:column;gap:.45em}
.prose strong{color:var(--white)}
.prose a{color:var(--cyan);border-bottom:1px solid rgba(53,240,208,.4)}

/* ---------- 5. 文字组件 ---------- */
.index-label{
  display:inline-block;font-family:var(--font-mono);font-size:11px;
  letter-spacing:.18em;text-transform:uppercase;color:var(--cyan);
}
.index-label--muted{color:var(--muted)}
.display{font-weight:900;font-size:clamp(32px,6vw,68px);line-height:1.03;letter-spacing:-.02em}
.lead{font-size:clamp(15px,1.6vw,17px);line-height:1.85;color:var(--muted);max-width:46ch}
.chapter-num{
  font-family:var(--font-mono);font-weight:200;font-size:clamp(72px,13vw,150px);
  line-height:.85;letter-spacing:-.05em;color:rgba(53,240,208,.14);
  -webkit-text-stroke:1px rgba(53,240,208,.32);
}
.data-num{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:-.01em}

/* ---------- 6. 按钮 / 标签 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:10px;
  padding:12px 22px;border-radius:999px;border:1px solid transparent;
  font-size:15px;font-weight:700;letter-spacing:.02em;
  transition:background-color .2s ease,color .2s ease,border-color .2s ease,transform .2s ease;
}
.btn--primary{background:var(--orange);color:#1A0C03;box-shadow:0 16px 34px -20px rgba(255,138,61,.95)}
.btn--primary:hover{background:#FFA165;transform:translateY(-2px)}
.btn--ghost{border-color:var(--line);color:var(--white);background:rgba(53,240,208,.04)}
.btn--ghost:hover{border-color:var(--cyan);color:var(--cyan)}
.btn--cyan{background:rgba(53,240,208,.12);border-color:rgba(53,240,208,.42);color:var(--cyan)}
.btn--cyan:hover{background:rgba(53,240,208,.2)}
.btn--block{width:100%}
.chip{
  display:inline-flex;align-items:center;gap:8px;padding:8px 15px;border-radius:999px;
  border:1px solid var(--line);color:var(--muted);font-size:13px;font-family:var(--font-mono);
  letter-spacing:.06em;transition:color .2s,border-color .2s,background-color .2s;
}
.chip:hover{color:var(--cyan);border-color:rgba(53,240,208,.45)}
.chip.is-active,.chip[aria-pressed="true"]{background:rgba(53,240,208,.14);border-color:var(--cyan);color:var(--cyan)}
.tag{
  display:inline-flex;align-items:center;font-family:var(--font-mono);font-size:10px;
  letter-spacing:.16em;padding:4px 10px;border-radius:var(--r-sm);
  background:rgba(255,194,75,.14);color:var(--amber);border:1px solid rgba(255,194,75,.3);
}

/* ---------- 7. 卡片 ---------- */
.card{
  position:relative;background:var(--panel);border:1px solid var(--line);
  border-radius:var(--r-lg);padding:clamp(18px,2.4vw,26px);
  transition:border-color .24s ease,transform .24s ease;
}
.card:hover{border-color:rgba(53,240,208,.4);transform:translateY(-3px)}
.card--glow{border-color:rgba(53,240,208,.45);box-shadow:0 0 0 1px rgba(53,240,208,.18),0 26px 60px -40px rgba(53,240,208,.6)}
.card--data{background:var(--panel-2);border-radius:var(--r-sm);font-family:var(--font-mono);font-variant-numeric:tabular-nums}
.card__title{font-size:19px;font-weight:800;letter-spacing:-.01em;color:var(--white)}
.card__meta{margin-top:8px;font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;color:var(--muted)}

/* ---------- 8. 图片容器（页面阶段放图） ---------- */
.media{
  position:relative;overflow:hidden;aspect-ratio:16/9;
  border-radius:var(--r-lg);border:1px solid var(--line);
  background:linear-gradient(165deg,var(--panel-2),var(--ink));
}
.media--16x9{aspect-ratio:16/9}
.media--4x3{aspect-ratio:4/3}
.media--1x1{aspect-ratio:1/1}
.media--wide{aspect-ratio:21/9}
.media img,.media__img{
  position:absolute;inset:0;width:100%;height:100%;object-fit:cover;
  filter:saturate(1.05) contrast(1.06);
}
.media__placeholder{
  position:absolute;inset:0;display:flex;align-items:flex-end;padding:18px;
  background:
    radial-gradient(120% 100% at 18% 100%,rgba(53,240,208,.22),transparent 58%),
    radial-gradient(90% 80% at 88% 10%,rgba(255,138,61,.18),transparent 60%),
    repeating-linear-gradient(0deg,rgba(233,245,241,.05) 0 1px,transparent 1px 5px),
    linear-gradient(165deg,var(--panel-2),var(--ink));
}
.media__placeholder::after{
  content:"";position:absolute;inset:0;
  background:radial-gradient(120% 120% at 50% 45%,transparent 42%,rgba(0,0,0,.6));
}
.media__badge{
  position:absolute;top:14px;left:14px;z-index:2;font-family:var(--font-mono);
  font-size:10px;letter-spacing:.16em;padding:5px 10px;border-radius:var(--r-sm);
  background:rgba(6,17,15,.78);color:var(--cyan);border:1px solid rgba(53,240,208,.35);
}
.media__caption{margin-top:10px;font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;color:var(--muted)}

/* ---------- 9. 数据表 ---------- */
.data-table{width:100%;font-family:var(--font-mono);font-variant-numeric:tabular-nums;font-size:13.5px}
.data-table caption{text-align:left;font-family:var(--font-sans);font-size:12px;letter-spacing:.14em;color:var(--muted);padding-bottom:10px}
.data-table th{
  font-size:11px;font-weight:600;letter-spacing:.14em;color:var(--muted);text-align:left;
  padding:10px 12px;border-bottom:1px solid var(--line);white-space:nowrap;
}
.data-table td{padding:12px;border-bottom:1px solid rgba(44,74,67,.6);color:var(--white)}
.data-table tbody tr:nth-child(even){background:var(--panel-2)}
.data-table tbody tr:hover{background:rgba(53,240,208,.07)}
.data-table .is-num{text-align:right;color:var(--cyan)}

/* ---------- 10. 面包屑 ---------- */
.breadcrumbs{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;color:var(--muted);
}
.breadcrumbs a:hover{color:var(--cyan)}
.breadcrumbs [aria-current="page"]{color:var(--white)}
.breadcrumbs__sep{color:var(--line)}

/* ---------- 11. 出场动效 ---------- */
.has-js .reveal{opacity:0;transform:translateY(14px);transition:opacity .6s ease,transform .6s ease}
.has-js .reveal.is-in{opacity:1;transform:none}

/* ---------- 12. 头部：桌面侧边轨道 / 移动顶栏 + 抽屉 ---------- */
.skip-link{
  position:fixed;top:10px;left:10px;z-index:120;transform:translateY(-220%);
  padding:10px 18px;border-radius:999px;background:var(--cyan);color:#04100D;
  font-size:13px;font-weight:700;transition:transform .2s ease;
}
.skip-link:focus{transform:translateY(0)}

.site-header{position:fixed;top:0;left:0;right:0;z-index:90}
.header-bar{
  position:relative;z-index:92;display:none;align-items:center;gap:12px;
  height:56px;padding:0 14px;background:rgba(6,17,15,.94);
  border-bottom:1px solid var(--line);backdrop-filter:blur(10px);
  transition:height .24s ease;
}
.header-bar__brand{display:flex;align-items:baseline;gap:1px;flex:0 0 auto}
.header-bar__mark{font-family:var(--font-mono);font-size:16px;font-weight:800;letter-spacing:-.02em;color:var(--cyan)}
.header-bar__cn{font-size:15px;font-weight:700;color:var(--white)}
.header-bar__tagline{
  flex:1 1 auto;min-width:0;margin-left:auto;text-align:right;
  font-size:11px;letter-spacing:.1em;color:var(--muted);
  white-space:nowrap;overflow:hidden;text-overflow:ellipsis;
  transition:opacity .24s ease;
}
.site-header[data-compact] .header-bar{height:48px}
.site-header[data-compact] .header-bar__tagline{opacity:0}

.nav-toggle{
  display:inline-flex;align-items:center;gap:9px;flex:0 0 auto;
  padding:8px 14px;border-radius:999px;border:1px solid var(--line);
  color:var(--white);font-size:13px;letter-spacing:.1em;
  transition:border-color .2s ease,color .2s ease;
}
.nav-toggle:hover{border-color:var(--cyan);color:var(--cyan)}
.nav-toggle__bars{position:relative;width:16px;height:2px;border-radius:2px;background:var(--cyan)}
.nav-toggle__bars::before,.nav-toggle__bars::after{
  content:"";position:absolute;left:0;width:16px;height:2px;border-radius:2px;background:var(--cyan);
  transition:transform .2s ease,opacity .2s ease;
}
.nav-toggle__bars::before{top:-5px}
.nav-toggle__bars::after{top:5px}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars{background:transparent}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before{transform:translateY(5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after{transform:translateY(-5px) rotate(-45deg)}
.nav-toggle__text{font-weight:600}

/* 轨道（桌面常驻） */
.rail{
  display:flex;flex-direction:column;align-items:center;gap:16px;
  height:100%;padding:18px 0 24px;
  background:linear-gradient(180deg,rgba(11,31,27,.97),rgba(6,17,15,.99));
  border-right:1px solid var(--line);
  overflow-y:auto;scrollbar-width:none;
}
.rail::-webkit-scrollbar{display:none}
.rail__top{display:flex;flex-direction:column;align-items:center;gap:8px;width:100%}
.rail__brand{display:flex;flex-direction:column;align-items:center;line-height:1.05;padding:2px 6px}
.rail__brand-mark{font-family:var(--font-mono);font-size:15px;font-weight:800;letter-spacing:-.02em;color:var(--cyan)}
.rail__brand-cn{font-size:12px;font-weight:700;letter-spacing:.3em;text-indent:.3em;color:var(--white)}
.rail__close{
  display:none;align-items:center;justify-content:center;width:34px;height:34px;
  border-radius:50%;border:1px solid var(--line);color:var(--muted);font-size:13px;
  transition:border-color .2s,color .2s;
}
.rail__close:hover{border-color:var(--cyan);color:var(--cyan)}
.rail__status{display:flex;flex-direction:column;align-items:center;gap:10px;padding-top:4px}
.rail__dot{width:6px;height:6px;border-radius:50%;background:var(--cyan);box-shadow:0 0 10px var(--cyan);animation:railPulse 2.6s ease-in-out infinite}
.rail__status-text{
  writing-mode:vertical-rl;text-orientation:upright;
  font-family:var(--font-mono);font-size:10px;letter-spacing:.18em;color:var(--muted);
}
@keyframes railPulse{0%,100%{opacity:1}50%{opacity:.28}}

.rail__nav{display:flex;flex-direction:column;align-items:center;width:100%}
.nav-list{display:flex;flex-direction:column;align-items:center;gap:2px;width:100%}
.nav-item{display:block}
.nav-link{
  position:relative;display:flex;flex-direction:column;align-items:center;gap:6px;
  padding:11px 8px;border-radius:14px;color:var(--muted);
  transition:color .2s ease,background-color .2s ease;
}
.nav-link__idx{font-family:var(--font-mono);font-size:9px;letter-spacing:.1em;opacity:.75}
.nav-link__label{writing-mode:vertical-rl;text-orientation:upright;font-size:12.5px;font-weight:600;letter-spacing:.14em}
.nav-link:hover{color:var(--cyan-soft);background:rgba(53,240,208,.07)}
.nav-link[aria-current="page"]{color:var(--cyan);background:rgba(53,240,208,.1)}
.nav-link[aria-current="page"]::before{
  content:"";position:absolute;left:-6px;top:10px;bottom:10px;width:3px;border-radius:2px;
  background:var(--cyan);box-shadow:0 0 12px rgba(53,240,208,.85);
}

.rail__foot{display:flex;flex-direction:column;align-items:center;gap:12px;margin-top:auto;padding-top:18px;width:100%}
.rail__cta{
  writing-mode:vertical-rl;text-orientation:upright;
  font-size:12.5px;font-weight:700;letter-spacing:.16em;color:#1A0C03;
  background:var(--orange);border-radius:16px;padding:16px 9px;
  box-shadow:0 14px 30px -16px rgba(255,138,61,.95);
  transition:background-color .2s ease,transform .2s ease;
}
.rail__cta:hover{background:#FFA165;transform:translateY(-2px)}
.rail__util{
  writing-mode:vertical-rl;text-orientation:upright;
  font-size:11px;letter-spacing:.16em;color:var(--muted);padding:6px 0;
  transition:color .2s ease;
}
.rail__util:hover{color:var(--cyan)}

/* 遮罩 */
.nav-scrim{
  position:fixed;inset:0;z-index:94;background:rgba(3,8,7,.72);
  opacity:0;visibility:hidden;pointer-events:none;
  transition:opacity .28s ease,visibility .28s step-end;
}
.nav-scrim[data-open]{opacity:1;visibility:visible;pointer-events:auto;transition:opacity .28s ease}

/* 阅读进度 + 返回顶部 */
.scroll-progress{
  position:fixed;top:0;left:0;right:0;height:2px;z-index:99;
  background:rgba(53,240,208,.1);pointer-events:none;
}
.scroll-progress__bar{
  display:block;width:100%;height:100%;transform:scaleX(0);transform-origin:0 50%;
  background:linear-gradient(90deg,var(--cyan),var(--cyan-soft));
  box-shadow:0 0 12px rgba(53,240,208,.8);
}
.to-top{
  position:fixed;right:16px;bottom:16px;z-index:88;
  display:flex;align-items:center;justify-content:center;
  width:46px;height:46px;border-radius:50%;
  border:1px solid rgba(53,240,208,.45);background:rgba(11,31,27,.94);
  color:var(--cyan);font-size:17px;line-height:1;
  box-shadow:0 18px 40px -24px rgba(0,0,0,.9);backdrop-filter:blur(6px);
  transition:transform .2s ease,background-color .2s ease;
}
.to-top[hidden]{display:none}
.to-top:hover{transform:translateY(-3px);background:rgba(53,240,208,.16)}
.to-top__arrow{font-family:var(--font-mono)}

/* ---------- 13. 页脚 ---------- */
.site-footer{
  position:relative;margin-top:0;padding:clamp(48px,7vw,92px) 0 28px;
  background:linear-gradient(180deg,#081815,var(--ink));
  border-top:1px solid var(--line);overflow:hidden;
}
.site-footer::before{
  content:"";position:absolute;top:0;left:0;right:0;height:1px;
  background:linear-gradient(90deg,transparent,rgba(53,240,208,.65),transparent);
}
.footer-head{
  display:flex;flex-wrap:wrap;align-items:flex-end;gap:20px;
  padding-bottom:clamp(22px,3.4vw,38px);border-bottom:1px solid var(--line);
}
.footer-mark{font-family:var(--font-mono);font-size:26px;font-weight:800;letter-spacing:-.02em;color:var(--white)}
.footer-mark__cn{font-family:var(--font-sans);color:var(--cyan);margin-left:2px}
.footer-tagline{margin-top:6px;font-size:13px;letter-spacing:.08em;color:var(--muted)}
.footer-claim{
  margin-left:auto;max-width:32ch;font-size:15px;line-height:1.75;color:var(--white);
  border-left:2px solid var(--orange);padding-left:14px;
}
.footer-grid{
  display:grid;grid-template-columns:repeat(4,minmax(0,1fr));
  gap:clamp(20px,3vw,44px);padding:clamp(28px,4vw,50px) 0 0;
}
.footer-col__title{
  font-family:var(--font-mono);font-size:11px;font-weight:600;letter-spacing:.18em;
  text-transform:uppercase;color:var(--cyan);margin-bottom:14px;
}
.footer-list{display:flex;flex-direction:column;gap:10px}
.footer-link{font-size:14px;color:var(--muted);transition:color .2s ease}
.footer-link:hover{color:var(--cyan)}
.footer-col--contact{grid-column:span 1}
.contact-list{display:flex;flex-direction:column;gap:12px}
.contact-item{display:flex;flex-wrap:wrap;align-items:center;gap:8px;font-size:13.5px}
.contact-item__label{
  font-family:var(--font-mono);font-size:10px;letter-spacing:.16em;color:var(--muted);
  border:1px solid var(--line);border-radius:999px;padding:2px 9px;
}
.contact-item__value{font-family:var(--font-mono);font-size:12.5px;color:var(--white);word-break:break-all}
.copy-btn{
  border:1px solid rgba(53,240,208,.35);background:rgba(53,240,208,.08);color:var(--cyan);
  font-size:11px;letter-spacing:.08em;padding:3px 11px;border-radius:999px;
  transition:background-color .2s ease,color .2s ease,border-color .2s ease;
}
.copy-btn:hover{background:rgba(53,240,208,.2)}
.copy-btn.is-done{background:var(--orange);border-color:var(--orange);color:#1A0C03}
.contact-note{
  margin-top:clamp(26px,3.4vw,42px);max-width:64ch;padding-top:16px;
  border-top:1px dashed var(--line);
  font-size:12.5px;line-height:1.85;color:var(--muted);
}
.footer-bottom{
  display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px 24px;
  margin-top:20px;padding-top:20px;border-top:1px solid var(--line);
}
.footer-legal{display:flex;flex-wrap:wrap;align-items:center;gap:10px;font-size:13px}
.footer-sep{color:var(--line)}
.footer-meta{font-family:var(--font-mono);font-size:12px;letter-spacing:.04em;color:var(--muted)}
.footer-icp{color:var(--muted)}

/* ---------- 14. 响应式 ---------- */
@media (max-width:899px){
  #main-content{padding-top:56px}
  .nav-scrim{display:block}
  .header-bar{display:flex}
  .skip-link{left:10px}

  .rail{
    position:fixed;top:0;left:0;bottom:0;z-index:95;
    width:min(80vw,330px);height:100%;padding:20px 18px 30px;
    align-items:stretch;gap:18px;
    background:linear-gradient(180deg,var(--panel),var(--ink) 72%);
    border-right:1px solid var(--line);
    box-shadow:40px 0 90px -50px rgba(0,0,0,.95);
    transform:translateX(-102%);visibility:hidden;
    transition:transform .32s cubic-bezier(.4,0,.2,1),visibility .32s step-end;
  }
  .rail[data-open]{transform:none;visibility:visible;transition:transform .32s cubic-bezier(.4,0,.2,1)}
  .rail__top{flex-direction:row;align-items:center;justify-content:space-between;gap:12px}
  .rail__brand{flex-direction:row;align-items:baseline;gap:3px;padding:0}
  .rail__brand-mark{font-size:21px}
  .rail__brand-cn{font-size:21px;letter-spacing:.02em;text-indent:0}
  .rail__close{display:flex}
  .rail__status{flex-direction:row;align-items:center;gap:8px}
  .rail__status-text{writing-mode:horizontal-tb;text-orientation:mixed;letter-spacing:.16em}
  .nav-list{gap:0;align-items:stretch}
  .nav-link{
    flex-direction:row;align-items:center;justify-content:flex-start;gap:14px;
    padding:14px 8px;border-radius:0;border-bottom:1px solid var(--line);
  }
  .nav-link__label{writing-mode:horizontal-tb;text-orientation:mixed;font-size:15px;letter-spacing:.02em}
  .nav-link[aria-current="page"]{background:rgba(53,240,208,.07)}
  .nav-link[aria-current="page"]::before{left:0;top:14px;bottom:14px;width:2px}
  .rail__foot{flex-direction:column;align-items:stretch;gap:10px;padding-top:22px}
  .rail__cta{
    writing-mode:horizontal-tb;text-orientation:mixed;text-align:center;
    padding:14px;border-radius:999px;font-size:14px;
  }
  .rail__util{writing-mode:horizontal-tb;text-orientation:mixed;text-align:center;font-size:13px;padding:8px 0}

  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-claim{margin-left:0;max-width:44ch}
}
@media (min-width:900px){
  body{padding-left:var(--rail)}
  .site-header{width:var(--rail);height:100vh}
  .skip-link{left:calc(var(--rail) + 12px)}
  .rail{width:100%}
}
@media (max-width:640px){
  .footer-grid{grid-template-columns:1fr;gap:26px}
  .footer-bottom{flex-direction:column;align-items:flex-start}
}

/* ---------- 15. 降低动态效果 ---------- */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  .has-js .reveal{opacity:1;transform:none}
  .rail__dot{animation:none}
}