/* ==========================================================================
   302COM · /assets/site.css
   共享外壳：侧边轨道页头 / 编辑部页脚 / 目录型基础组件
   ========================================================================== */

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0}
img,svg,video{display:block;max-width:100%;height:auto}
button,input,select,textarea{font:inherit;color:inherit;background:none;border:0}
button{cursor:pointer}
ul,ol{list-style:none;margin:0;padding:0}
hr{border:0;border-top:1px solid var(--line-dark)}
::selection{background:var(--cyan);color:var(--ink)}

/* ---------- 2. 设计令牌 ---------- */
:root{
  --ink:#0B0F12;
  --ink-2:#141B21;
  --ink-3:#1B242C;
  --paper:#F4EFE6;
  --paper-2:#E6DED0;
  --warm-white:#FFFDF8;
  --cyan:#35E0D6;
  --amber:#F2A03D;
  --vermilion:#C7442E;
  --gray:#6B7780;
  --gray-soft:#9CA8B2;
  --teal-ink:#0E3B3A;
  --teal-link:#0E6E68;

  --line-dark:rgba(244,239,230,.14);
  --line-dark-strong:rgba(244,239,230,.26);
  --line-light:rgba(11,15,18,.16);
  --cyan-soft:rgba(53,224,214,.12);
  --amber-soft:rgba(242,160,61,.14);

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

  --rail-w:264px;
  --rail-w-min:78px;
  --bar-h:64px;

  --shell-max:1180px;
  --gutter:clamp(20px,4vw,56px);
  --gap:clamp(16px,2.4vw,32px);

  --radius:4px;
  --radius-lg:10px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --shadow-lift:0 14px 32px rgba(0,0,0,.42);
  --shadow-paper:0 10px 26px rgba(0,0,0,.28);

  --anchor-offset:112px;
  --scroll-p:0;
}

/* ---------- 3. 基线排版 ---------- */
body{
  min-height:100vh;
  background:
    radial-gradient(900px 540px at 90% -12%, rgba(53,224,214,.10), transparent 62%),
    radial-gradient(760px 480px at 4% 106%, rgba(242,160,61,.08), transparent 60%),
    var(--ink);
  color:var(--paper);
  font-family:var(--font-sans);
  font-size:17px;
  font-weight:400;
  line-height:1.75;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{margin:0 0 .6em;color:var(--warm-white);line-height:1.24;font-weight:700}
h1{font-size:clamp(34px,5vw,56px)}
h2{font-size:clamp(23px,2.8vw,32px)}
h3{font-size:clamp(19px,2.1vw,24px);font-weight:500}
h4{font-size:17px;font-weight:500}
p{margin:0 0 1em}
p:last-child{margin-bottom:0}
a{color:var(--cyan);text-decoration:none;transition:color .2s var(--ease)}
a:hover{text-decoration:underline;text-underline-offset:3px}
code,kbd,samp,.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums}
strong,b{font-weight:500;color:var(--warm-white)}

/* ---------- 4. 可访问性工具 ---------- */
:focus{outline:none}
:focus-visible{outline:2px solid var(--cyan);outline-offset:2px;border-radius:2px}
.visually-hidden{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}
[id]{scroll-margin-top:var(--anchor-offset)}
.skip-link{
  position:fixed;top:10px;left:10px;z-index:220;
  padding:11px 18px;border-radius:var(--radius);
  background:var(--cyan);color:var(--ink);font-size:14px;font-weight:700;
  transform:translateY(-200%);
  transition:transform .2s var(--ease);
}
.skip-link:focus{transform:translateY(0);text-decoration:none}

/* ---------- 5. 容器与网格 ---------- */
.shell{width:100%;max-width:var(--shell-max);margin:0 auto;padding:0 var(--gutter)}
.band{padding:clamp(40px,5.6vw,84px) 0}
.grid{display:grid;gap:var(--gap)}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--aside{grid-template-columns:minmax(0,1fr) minmax(220px,320px);align-items:start}
.stack{display:flex;flex-direction:column;gap:var(--gap)}
@media(max-width:900px){
  .grid--2,.grid--3,.grid--aside{grid-template-columns:minmax(0,1fr)}
}

/* ---------- 6. 侧边轨道页头 ---------- */
.site-rail{
  position:fixed;top:0;left:0;bottom:0;width:var(--rail-w);z-index:90;
  display:flex;flex-direction:column;
  padding:20px 0 0;
  color:var(--paper);
  background:
    repeating-linear-gradient(0deg, rgba(53,224,214,.045) 0 1px, transparent 1px 26px),
    linear-gradient(180deg, rgba(20,27,33,.94), rgba(11,15,18,.98));
  border-right:1px solid var(--line-dark);
  -webkit-backdrop-filter:blur(14px);
  backdrop-filter:blur(14px);
  overflow:hidden;
  transition:width .3s var(--ease);
}
.rail-bar{
  display:flex;flex-direction:column;gap:14px;
  padding:0 18px 18px;
  border-bottom:1px solid var(--line-dark);
}
.brand-lockup{display:flex;align-items:center;gap:12px;color:var(--paper);text-decoration:none}
.brand-lockup:hover{color:var(--warm-white);text-decoration:none}
.brand-mark{
  flex:0 0 auto;display:grid;place-items:center;width:44px;height:44px;
  background:var(--cyan);color:var(--ink);border-radius:3px;
  font-family:var(--font-mono);font-size:15px;font-weight:700;letter-spacing:.04em;
  box-shadow:0 0 0 1px rgba(53,224,214,.4), 0 8px 20px rgba(53,224,214,.16);
}
.brand-text{display:flex;flex-direction:column;gap:3px;min-width:0}
.brand-name{font-family:var(--font-mono);font-size:17px;font-weight:700;letter-spacing:.16em;color:var(--warm-white)}
.brand-tag{font-size:11.5px;line-height:1.55;color:var(--gray-soft)}

.nav-toggle{
  display:none;align-items:center;gap:9px;
  padding:9px 13px;border-radius:3px;
  background:rgba(53,224,214,.08);border:1px solid rgba(53,224,214,.35);
  color:var(--warm-white);font-size:13px;letter-spacing:.1em;
  transition:background .2s var(--ease),border-color .2s var(--ease);
}
.nav-toggle:hover{background:rgba(53,224,214,.16);border-color:var(--cyan)}
.nav-toggle-icon{display:flex;flex-direction:column;gap:4px;width:16px}
.nav-toggle-icon i{display:block;height:2px;background:var(--cyan);transition:transform .25s var(--ease),opacity .2s linear}
.site-rail[data-open] .nav-toggle-icon i:nth-child(1){transform:translateY(6px) rotate(45deg)}
.site-rail[data-open] .nav-toggle-icon i:nth-child(2){opacity:0}
.site-rail[data-open] .nav-toggle-icon i:nth-child(3){transform:translateY(-6px) rotate(-45deg)}
.nav-toggle-text{font-family:var(--font-mono)}

.rail-scrim{display:none}

.rail-body{
  display:flex;flex-direction:column;gap:22px;
  flex:1 1 auto;min-height:0;overflow-y:auto;overscroll-behavior:contain;
  padding:20px 18px 18px;
  scrollbar-width:thin;scrollbar-color:rgba(53,224,214,.3) transparent;
}
.rail-body::-webkit-scrollbar{width:6px}
.rail-body::-webkit-scrollbar-thumb{background:rgba(53,224,214,.28);border-radius:3px}

.rail-label{
  margin:0 0 10px;
  font-family:var(--font-mono);font-size:10.5px;letter-spacing:.22em;
  color:var(--cyan);opacity:.9;
}
.rail-label::after{content:"";display:block;width:26px;height:1px;margin-top:6px;background:currentColor;opacity:.5}

.nav-list{counter-reset:railnav;display:flex;flex-direction:column;gap:2px}
.nav-link{
  position:relative;display:flex;align-items:baseline;gap:12px;
  padding:9px 12px;border-left:2px solid transparent;border-radius:3px;
  color:var(--paper);font-size:15px;text-decoration:none;
  transition:background .2s var(--ease),border-color .2s var(--ease),color .2s var(--ease);
}
.nav-link::before{
  counter-increment:railnav;content:counter(railnav,decimal-leading-zero);
  font-family:var(--font-mono);font-size:10.5px;letter-spacing:.08em;color:var(--gray);
  transition:color .2s var(--ease);
}
.nav-link:hover{background:rgba(53,224,214,.07);border-left-color:rgba(53,224,214,.45);color:var(--warm-white);text-decoration:none}
.nav-link:hover::before{color:var(--cyan)}
.nav-link[aria-current="page"]{background:rgba(53,224,214,.12);border-left-color:var(--cyan);color:var(--warm-white)}
.nav-link[aria-current="page"]::before{color:var(--cyan)}
.nav-text{min-width:0}

.quick-list{display:flex;flex-direction:column;gap:6px}
.quick-link{
  position:relative;display:block;
  padding:7px 10px 7px 26px;border:1px solid var(--line-dark);border-radius:3px;
  background:rgba(244,239,230,.04);
  color:var(--paper);font-size:13.5px;text-decoration:none;
  transition:background .2s var(--ease),border-color .2s var(--ease),transform .2s var(--ease),color .2s var(--ease);
}
.quick-link::before{content:"";position:absolute;left:11px;top:50%;width:7px;height:7px;margin-top:-3.5px;border-radius:1px;background:var(--cyan)}
.quick-link--case::before{background:var(--amber)}
.quick-link:hover{background:rgba(244,239,230,.09);border-color:var(--line-dark-strong);color:var(--warm-white);transform:translateX(2px);text-decoration:none}

.rail-meta{margin-top:auto;padding-top:18px;border-top:1px solid var(--line-dark)}
.meta-line{display:flex;flex-direction:column;gap:2px;margin:0 0 10px}
.meta-key{font-family:var(--font-mono);font-size:10px;letter-spacing:.2em;color:var(--gray)}
.meta-value{font-family:var(--font-mono);font-size:12.5px;color:var(--paper);word-break:break-all}

.rail-collapse{
  margin-top:14px;display:inline-flex;align-items:center;gap:8px;
  padding:8px 10px;border:1px dashed var(--line-dark-strong);border-radius:3px;
  color:var(--gray-soft);font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.rail-collapse:hover{color:var(--cyan);border-color:rgba(53,224,214,.5)}
.rail-collapse-icon{position:relative;width:16px;height:1px;background:currentColor}
.rail-collapse-icon::after{content:"";position:absolute;left:0;top:-3px;width:7px;height:7px;border-left:1px solid currentColor;border-bottom:1px solid currentColor;transform:rotate(45deg)}

.rail-progress{position:absolute;top:0;right:0;bottom:0;width:2px;background:rgba(53,224,214,.14);pointer-events:none}
.rail-progress-bar{
  display:block;width:100%;height:100%;
  background:linear-gradient(180deg,var(--cyan),var(--amber));
  transform:scaleY(var(--scroll-p,0));transform-origin:top center;
  transition:transform .12s linear;
}

/* ---------- 7. 页脚 ---------- */
.site-footer{
  position:relative;
  margin-top:clamp(56px,8vw,110px);
  background:linear-gradient(180deg, rgba(14,20,25,.94), rgba(11,15,18,1));
  border-top:1px solid var(--line-dark);
  color:var(--paper);
}
.site-footer::before{
  content:"";display:block;height:3px;
  background:linear-gradient(90deg,var(--cyan) 0 22%,var(--amber) 22% 38%,var(--vermilion) 38% 46%,rgba(244,239,230,.12) 46% 100%);
}
.footer-grid{
  display:grid;grid-template-columns:1.35fr 1fr 1fr 1.5fr;
  gap:clamp(24px,3.4vw,46px);
  padding:clamp(36px,5vw,64px) 0 clamp(24px,3vw,38px);
}
.footer-col{min-width:0}
.footer-lockup{display:flex;align-items:center;gap:10px;margin:0 0 12px}
.footer-mark{
  display:grid;place-items:center;width:38px;height:38px;border-radius:3px;
  border:1px solid rgba(53,224,214,.55);color:var(--cyan);
  font-family:var(--font-mono);font-size:13px;font-weight:700;
}
.footer-name{font-family:var(--font-mono);font-size:16px;letter-spacing:.18em;color:var(--warm-white)}
.footer-tagline{margin:0 0 10px;font-size:14px;color:var(--paper-2)}
.footer-note{margin:0;font-size:12.5px;line-height:1.7;color:var(--gray-soft)}
.footer-heading{
  margin:0 0 14px;font-family:var(--font-mono);font-size:10.5px;letter-spacing:.22em;color:var(--cyan);
}
.footer-heading::after{content:"";display:block;width:24px;height:1px;margin-top:7px;background:currentColor;opacity:.45}
.footer-links{display:flex;flex-direction:column;gap:9px}
.footer-link{
  display:inline-block;color:var(--paper);font-size:14.5px;text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .2s var(--ease),transform .2s var(--ease),border-color .2s var(--ease);
}
.footer-link:hover{color:var(--cyan);border-bottom-color:rgba(53,224,214,.5);transform:translateX(2px);text-decoration:none}
.footer-contact{display:flex;flex-direction:column;gap:12px;margin:0 0 14px}
.contact-item{display:flex;flex-direction:column;gap:3px}
.contact-label{font-family:var(--font-mono);font-size:10px;letter-spacing:.2em;color:var(--gray)}
.contact-value{font-family:var(--font-mono);font-size:13.5px;color:var(--warm-white);word-break:break-word}
.contact-value--plain{font-family:var(--font-sans);font-size:14px;line-height:1.7;letter-spacing:.01em}
.footer-base{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px 26px;
  padding:20px 0 30px;border-top:1px solid var(--line-dark);
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.06em;color:var(--gray);
}
.footer-legal,.footer-icp{margin:0}
.footer-icp{color:var(--paper-2)}
@media(max-width:980px){.footer-grid{grid-template-columns:1fr 1fr}}
@media(max-width:620px){.footer-grid{grid-template-columns:1fr;gap:32px}}

/* ---------- 8. 按钮与胶囊 ---------- */
.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:11px 20px;border:1px solid transparent;border-radius:3px;
  background:transparent;color:var(--paper);
  font-family:var(--font-sans);font-size:14.5px;font-weight:500;letter-spacing:.02em;
  text-decoration:none;
  transition:transform .2s var(--ease),background .2s var(--ease),border-color .2s var(--ease),color .2s var(--ease);
}
.btn:hover{transform:translateY(-2px);text-decoration:none}
.btn--primary{background:var(--cyan);color:var(--ink);font-weight:700}
.btn--primary:hover{background:#5ce9e0;color:var(--ink);box-shadow:0 10px 24px rgba(53,224,214,.22)}
.btn--accent{background:var(--amber);color:var(--ink);font-weight:700}
.btn--accent:hover{background:#f7b25c;color:var(--ink);box-shadow:0 10px 24px rgba(242,160,61,.22)}
.btn--ghost{border-color:var(--line-dark-strong);color:var(--paper)}
.btn--ghost:hover{border-color:var(--cyan);color:var(--cyan)}
.chip{
  display:inline-flex;align-items:center;gap:7px;
  padding:7px 14px;border-radius:999px;border:1px solid var(--line-dark-strong);
  background:rgba(244,239,230,.04);color:var(--paper);
  font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;
  transition:background .2s var(--ease),border-color .2s var(--ease),color .2s var(--ease);
}
.chip:hover{border-color:rgba(53,224,214,.5);color:var(--warm-white)}
.chip[aria-pressed="true"]{background:var(--cyan-soft);border-color:var(--cyan);color:var(--cyan)}

/* ---------- 9. 面包屑 ---------- */
.breadcrumbs{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  margin:0 0 22px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;color:var(--gray);
}
.breadcrumbs li{display:flex;align-items:center;gap:8px}
.breadcrumbs li+li::before{content:"/";color:rgba(107,119,128,.7)}
.breadcrumb-link{color:var(--paper-2);text-decoration:none}
.breadcrumb-link:hover{color:var(--cyan)}
.breadcrumb-current{color:var(--cyan)}

/* ---------- 10. 章节头与正文 ---------- */
.section-head{
  display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;gap:14px;
  margin:0 0 26px;padding-bottom:14px;border-bottom:1px solid var(--line-dark);
}
.eyebrow{margin:0 0 8px;font-family:var(--font-mono);font-size:11px;letter-spacing:.24em;color:var(--cyan)}
.section-title{margin:0;font-size:clamp(22px,2.6vw,30px)}
.lede{margin:0;max-width:62ch;font-size:clamp(15px,1.5vw,17px);line-height:1.8;color:var(--paper-2)}
.prose{max-width:68ch;font-size:17px;line-height:1.75;color:var(--paper)}
.prose p{margin:0 0 1.15em}
.prose ul{list-style:disc;padding-left:1.3em;margin:0 0 1.15em}
.prose li{margin:0 0 .4em}

/* ---------- 11. 面板与卡片 ---------- */
.panel{
  padding:clamp(18px,2.4vw,28px);
  border:1px solid var(--line-dark);border-radius:var(--radius-lg);
  background:linear-gradient(180deg, rgba(20,27,33,.84), rgba(11,15,18,.74));
  -webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);
}
.paper-card{
  padding:clamp(18px,2.4vw,28px);
  border-radius:var(--radius-lg);
  background:var(--paper);color:var(--ink);
  box-shadow:var(--shadow-paper);
}
.paper-card h2,.paper-card h3,.paper-card h4{color:var(--ink)}
.paper-card a{color:var(--teal-link)}
.paper-card a:hover{color:var(--vermilion)}
.card-grid{display:grid;gap:var(--gap);grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}
.entry-card{
  position:relative;display:flex;flex-direction:column;gap:10px;
  padding:20px 20px 22px;border:1px solid var(--line-dark);border-radius:var(--radius-lg);
  background:linear-gradient(180deg, rgba(20,27,33,.86), rgba(11,15,18,.78));
  color:var(--paper);text-decoration:none;
  transition:transform .22s var(--ease),border-color .22s var(--ease),box-shadow .22s var(--ease),color .2s var(--ease);
}
.entry-card:hover{transform:translateY(-2px);border-color:rgba(53,224,214,.45);box-shadow:var(--shadow-lift);color:var(--warm-white);text-decoration:none}
.entry-num{font-family:var(--font-mono);font-size:11px;letter-spacing:.2em;color:var(--cyan)}
.entry-title{font-size:18px;font-weight:500;line-height:1.4;color:var(--warm-white)}
.entry-meta{font-size:13px;line-height:1.65;color:var(--gray-soft)}

/* ---------- 12. 参数表 ---------- */
.spec-caption{display:block;margin:0 0 10px;font-family:var(--font-mono);font-size:11px;letter-spacing:.18em;color:var(--gray-soft)}
.spec-table{
  width:100%;border-collapse:collapse;overflow:hidden;
  background:var(--paper);color:var(--ink);border-radius:var(--radius-lg);
  font-family:var(--font-mono);font-variant-numeric:tabular-nums;font-size:14px;
}
.spec-table th,.spec-table td{padding:11px 14px;text-align:left;border-bottom:1px solid var(--line-light)}
.spec-table thead th{background:var(--paper-2);font-size:12px;font-weight:500;letter-spacing:.12em;color:#3B4248}
.spec-table tbody tr:last-child td{border-bottom:0}
.spec-table tbody tr:hover{background:rgba(53,224,214,.14)}
.spec-table .is-data{color:var(--teal-link);font-weight:400}

/* ---------- 13. 标签与旁注 ---------- */
.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 10px;border-radius:999px;border:1px solid var(--line-dark-strong);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;color:var(--paper-2);
}
.tag--data{color:var(--cyan);border-color:rgba(53,224,214,.4);background:var(--cyan-soft)}
.tag--case{color:var(--amber);border-color:rgba(242,160,61,.45);background:var(--amber-soft)}
.note{
  padding:14px 16px;border-left:2px solid var(--amber);border-radius:0 var(--radius) var(--radius) 0;
  background:var(--amber-soft);color:var(--paper-2);
  font-size:14.5px;line-height:1.7;
}
.note--data{border-left-color:var(--cyan);background:var(--cyan-soft)}

/* ---------- 14. 分段切换 ---------- */
.tabs{width:100%}
.tablist{
  display:flex;flex-wrap:wrap;gap:6px;
  padding:5px;border:1px solid var(--line-dark);border-radius:999px;
  background:rgba(244,239,230,.05);
}
.tab{
  padding:8px 18px;border-radius:999px;
  color:var(--paper-2);font-size:14px;
  transition:background .2s var(--ease),color .2s var(--ease);
}
.tab:hover{color:var(--warm-white)}
.tab[aria-selected="true"]{background:var(--cyan);color:var(--ink);font-weight:700}
.tabpanel{padding:22px 0 0}
.tabpanel[hidden]{display:none}

/* ---------- 15. 图片容器 ---------- */
.media-frame{
  position:relative;overflow:hidden;aspect-ratio:16/9;
  border:1px solid var(--line-dark);border-radius:var(--radius-lg);
  background:linear-gradient(158deg,var(--teal-ink), var(--ink-2) 62%, var(--ink));
}
.media-frame--wide{aspect-ratio:21/9}
.media-frame--tall{aspect-ratio:4/5}
.media-frame img{width:100%;height:100%;object-fit:cover;filter:saturate(.94) contrast(1.04)}
.media-frame::after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,transparent 55%, rgba(11,15,18,.55));pointer-events:none}
.media-caption{display:block;margin-top:10px;font-family:var(--font-mono);font-size:11.5px;letter-spacing:.06em;color:var(--gray-soft)}

/* ---------- 16. 显现动画 ---------- */
html.js [data-reveal]{opacity:0;transform:translateY(14px);transition:opacity .5s var(--ease),transform .5s var(--ease)}
html.js [data-reveal].is-visible{opacity:1;transform:none}

/* ---------- 17. 响应式：桌面轨道 / 移动抽屉 ---------- */
@media(min-width:1024px){
  body{padding-left:var(--rail-w);transition:padding-left .3s var(--ease)}
  :root{--anchor-offset:36px}
  html.rail-collapsed body{padding-left:var(--rail-w-min)}
  html.rail-collapsed .site-rail{width:var(--rail-w-min)}
  html.rail-collapsed .rail-label,
  html.rail-collapsed .rail-quick,
  html.rail-collapsed .rail-meta{display:none}
  html.rail-collapsed .brand-text,
  html.rail-collapsed .nav-text,
  html.rail-collapsed .rail-collapse-text{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap}
  html.rail-collapsed .rail-bar{padding-left:0;padding-right:0;align-items:center;gap:0}
  html.rail-collapsed .brand-lockup{justify-content:center}
  html.rail-collapsed .rail-body{padding-left:10px;padding-right:10px}
  html.rail-collapsed .nav-link{justify-content:center;gap:0;padding-left:6px;padding-right:6px}
  html.rail-collapsed .rail-collapse{margin-top:auto;justify-content:center}
  html.rail-collapsed .rail-collapse-icon{display:none}
}

@media(max-width:1023px){
  body{padding-top:var(--bar-h)}
  :root{--anchor-offset:90px}
  .site-rail{
    top:0;left:0;right:0;bottom:0;width:auto;
    padding:0;overflow:visible;
    background:transparent;border-right:0;
    -webkit-backdrop-filter:none;backdrop-filter:none;
    pointer-events:none;
  }
  .rail-bar{
    position:relative;z-index:3;
    flex-direction:row;align-items:center;justify-content:space-between;gap:12px;
    height:var(--bar-h);padding:0 16px;
    background:linear-gradient(180deg, rgba(16,22,28,.97), rgba(11,15,18,.95));
    border-bottom:1px solid var(--line-dark);
    pointer-events:auto;
  }
  .nav-toggle{display:inline-flex}
  .rail-body{
    position:absolute;top:var(--bar-h);left:0;bottom:0;z-index:2;
    width:min(340px,88vw);
    padding:20px 18px 32px;overflow-y:auto;
    background:linear-gradient(180deg, rgba(16,22,28,.99), rgba(11,15,18,.99));
    border-right:1px solid var(--line-dark);
    transform:translateX(-102%);
    transition:transform .32s var(--ease);
    pointer-events:auto;
  }
  .site-rail[data-open] .rail-body{transform:translateX(0)}
  .rail-scrim{
    display:block;position:absolute;top:var(--bar-h);left:0;right:0;bottom:0;z-index:1;
    padding:0;border:0;background:rgba(5,8,10,.68);
    opacity:0;visibility:hidden;pointer-events:none;
    transition:opacity .3s var(--ease),visibility .3s var(--ease);
  }
  .site-rail[data-open] .rail-scrim{opacity:1;visibility:visible;pointer-events:auto}
  .rail-collapse{display:none}
  .rail-progress{top:calc(var(--bar-h) - 2px);right:0;bottom:auto;left:0;width:auto;height:2px}
  .rail-progress-bar{transform:scaleX(var(--scroll-p,0));transform-origin:left center;background:linear-gradient(90deg,var(--cyan),var(--amber))}
}

/* ---------- 18. 减少动效 ---------- */
@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}
}