/* ==========================================================================
   加拿大预测站 · 全站共享样式 /assets/site.css
   骨架：侧边品牌轨道 + 正文区；材质：粗边框、硬阴影、等宽数据字
   ========================================================================== */

/* ---------- 1. 变量 ---------- */
:root{
  --maple:#D52B1E;
  --maple-soft:#FBE3E4;
  --navy:#0B1F3A;
  --navy-deep:#061226;
  --grey:#E6EAF0;
  --mist:#F8FAFC;
  --ink:#111827;
  --teal:#00A896;
  --gold:#F5B700;
  --slate:#64748B;

  --rail-w:272px;
  --wrap:1200px;
  --line:rgba(11,31,58,.14);
  --line-strong:rgba(11,31,58,.34);
  --line-light:rgba(248,250,252,.16);

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

  --fs-display:clamp(2.5rem,5.2vw,3.5rem);
  --fs-h1:clamp(1.875rem,3.4vw,2.5rem);
  --fs-h2:clamp(1.5rem,2.4vw,1.75rem);
  --fs-h3:1.25rem;
  --fs-note:.8125rem;
  --fs-mono:.875rem;

  --leaf:polygon(50% 0%,59% 17%,74% 10%,69% 29%,91% 24%,79% 43%,100% 50%,79% 57%,91% 76%,69% 71%,74% 90%,59% 83%,50% 100%,41% 83%,26% 90%,31% 71%,9% 76%,21% 57%,0% 50%,21% 43%,9% 24%,31% 29%,26% 10%,41% 17%);
}

/* ---------- 2. reset ---------- */
*,*::before,*::after{box-sizing:border-box;}
html{
  -webkit-text-size-adjust:100%;
  background:var(--navy-deep);
  scroll-behavior:smooth;
  scroll-padding-top:74px;
}
body{
  margin:0;
  background:var(--mist);
  color:var(--ink);
  font-family:var(--font-sans);
  font-size:16px;
  font-weight:400;
  line-height:1.75;
  letter-spacing:.01em;
}
h1,h2,h3,h4,h5,p,ul,ol,dl,figure,blockquote,pre{margin:0;}
ul,ol{padding:0;list-style:none;}
img,picture,svg,video{max-width:100%;display:block;}
a{color:inherit;}
button{font:inherit;color:inherit;background:none;border:0;}
table{border-collapse:collapse;width:100%;}
:focus-visible{outline:3px solid var(--gold);outline-offset:2px;border-radius:1px;}

.sr-only{
  position:absolute;width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip:rect(0 0 0 0);clip-path:inset(50%);white-space:nowrap;border:0;
}
.skip-link{
  position:fixed;top:10px;left:10px;z-index:300;
  transform:translateY(-200%);
  padding:.7rem 1.1rem;
  background:var(--maple);color:#fff;
  font-size:.875rem;font-weight:600;text-decoration:none;
  border:2px solid #fff;border-radius:2px;
  transition:transform .18s ease;
}
.skip-link:focus{transform:none;}

/* ---------- 3. 排版工具 ---------- */
.t-display{font-size:var(--fs-display);line-height:1.14;font-weight:600;letter-spacing:-.022em;}
.t-h1{font-size:var(--fs-h1);line-height:1.2;font-weight:600;letter-spacing:-.018em;}
.t-h2{font-size:var(--fs-h2);line-height:1.28;font-weight:600;letter-spacing:-.012em;}
.t-h3{font-size:var(--fs-h3);line-height:1.4;font-weight:600;letter-spacing:-.008em;}
.t-body{font-size:1rem;line-height:1.75;}
.t-note{font-size:var(--fs-note);line-height:1.7;color:var(--slate);}
.lede{font-size:1.0625rem;line-height:1.8;color:#334155;max-width:62ch;}
.mono{font-family:var(--font-mono);font-size:var(--fs-mono);letter-spacing:.02em;}

.eyebrow{
  display:inline-flex;align-items:center;gap:.65rem;
  font-family:var(--font-mono);font-size:.75rem;font-weight:500;
  letter-spacing:.2em;text-transform:uppercase;color:var(--maple);
}
.eyebrow::before{content:"";width:22px;height:2px;background:var(--maple);}

.rule{display:flex;align-items:center;gap:14px;margin:28px 0;}
.rule::before{content:"";width:48px;height:3px;background:var(--maple);flex:0 0 auto;}
.rule::after{content:"";flex:1;height:1px;background:var(--line);}

/* ---------- 4. 容器与分区 ---------- */
.wrap{width:100%;max-width:var(--wrap);margin:0 auto;padding:0 24px;}
.section{padding:64px 0;}
.section--tight{padding:40px 0;}
.section--wide{padding:88px 0;}
.section--grey{background:var(--grey);}
.section--maple{background:var(--maple-soft);}
.section--navy{background:var(--navy);color:rgba(248,250,252,.82);}
.section--navy h1,.section--navy h2,.section--navy h3{color:#fff;}
.section--navy .t-note,.section--navy .lede{color:rgba(248,250,252,.68);}
.section--navy .eyebrow{color:var(--gold);}
.section--navy .eyebrow::before{background:var(--gold);}

.stack>*+*{margin-top:1rem;}

.grid{display:grid;gap:20px;}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr));}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr));}
.grid--4{grid-template-columns:repeat(4,minmax(0,1fr));}
.grid--gap-sm{gap:12px;}

/* ---------- 5. 头部 · 品牌轨道 ---------- */
.site-header{position:relative;z-index:70;}

.rail{
  position:fixed;top:0;left:0;bottom:0;
  width:var(--rail-w);
  display:flex;flex-direction:column;
  padding:26px 20px 20px;
  background:var(--navy);
  color:var(--mist);
  border-right:3px solid var(--navy-deep);
  overflow:hidden;
}
.rail::after{
  content:"";position:absolute;top:0;right:-3px;width:3px;height:34%;
  background:var(--maple);
}
.rail::before{
  content:"";position:absolute;left:0;bottom:0;width:100%;height:180px;
  background:linear-gradient(180deg,rgba(6,18,38,0) 0%,rgba(6,18,38,.55) 100%);
  pointer-events:none;
}

.brand{display:flex;align-items:center;gap:12px;text-decoration:none;color:var(--mist);position:relative;}
.brand-glyph{
  width:34px;height:34px;flex:0 0 34px;
  background:var(--maple);
  clip-path:var(--leaf);
}
.brand-name{display:block;font-size:1.0625rem;font-weight:600;letter-spacing:.02em;line-height:1.25;}
.brand-sub{
  display:block;font-family:var(--font-mono);font-size:.6875rem;
  letter-spacing:.16em;color:rgba(248,250,252,.5);margin-top:2px;
}

.rail-vertical{
  position:absolute;top:124px;right:5px;
  writing-mode:vertical-rl;transform:rotate(180deg);
  font-family:var(--font-mono);font-size:.6875rem;
  letter-spacing:.34em;text-transform:uppercase;
  color:rgba(248,250,252,.2);
  pointer-events:none;user-select:none;
}

.rail-nav{position:relative;flex:1;display:flex;flex-direction:column;margin-top:26px;min-height:0;}
.nav-list{display:flex;flex-direction:column;gap:2px;}
.nav-item{display:block;}
.nav-link{
  display:flex;align-items:center;gap:12px;
  padding:11px 12px 11px 10px;
  border-left:3px solid transparent;
  color:rgba(248,250,252,.72);
  font-size:.9375rem;letter-spacing:.02em;text-decoration:none;
  transition:background .18s ease,color .18s ease,border-color .18s ease,transform .18s ease;
}
.nav-idx{
  font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.06em;
  color:rgba(248,250,252,.36);flex:0 0 auto;
}
.nav-label{display:block;}
.nav-link:hover,.nav-link:focus-visible{
  background:rgba(248,250,252,.07);
  color:#fff;border-left-color:var(--maple);
  transform:translateX(2px);
}
.nav-link[aria-current="page"]{
  background:rgba(213,43,30,.2);
  color:#fff;border-left-color:var(--maple);font-weight:600;
}
.nav-link[aria-current="page"] .nav-idx{color:var(--gold);}

.rail-foot{
  margin-top:auto;display:flex;flex-direction:column;gap:12px;
  padding-top:18px;border-top:1px solid var(--line-light);
}
.rail-version{
  align-self:flex-start;
  font-family:var(--font-mono);font-size:.75rem;letter-spacing:.08em;
  color:rgba(248,250,252,.62);text-decoration:none;
  border-bottom:1px dashed rgba(248,250,252,.3);padding-bottom:2px;
  transition:color .18s ease,border-color .18s ease;
}
.rail-version:hover{color:var(--gold);border-bottom-color:var(--gold);}
.rail-collect{
  display:flex;align-items:center;justify-content:center;gap:8px;
  width:100%;padding:10px 12px;
  background:var(--maple);color:#fff;
  font-size:.875rem;font-weight:600;letter-spacing:.04em;
  border-radius:2px;cursor:pointer;
  box-shadow:3px 3px 0 0 rgba(6,18,38,.9);
  transition:transform .16s ease,box-shadow .16s ease,background .16s ease;
}
.rail-collect:hover{transform:translate(-1px,-1px);box-shadow:5px 5px 0 0 rgba(6,18,38,.9);}
.rail-collect:active{transform:translate(2px,2px);box-shadow:1px 1px 0 0 rgba(6,18,38,.9);}
.rail-collect[data-collected]{background:var(--teal);}
.collect-icon{
  width:12px;height:12px;flex:0 0 12px;
  border:2px solid rgba(255,255,255,.85);border-radius:1px;
}
.rail-collect[data-collected] .collect-icon{background:rgba(255,255,255,.9);}

.update-badge{
  display:flex;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.08em;
  color:rgba(248,250,252,.58);
}
.update-dot{
  width:8px;height:8px;flex:0 0 8px;border-radius:50%;
  background:var(--teal);box-shadow:0 0 0 4px rgba(0,168,150,.18);
  animation:pulse-dot 2.4s ease-in-out infinite;
}
@keyframes pulse-dot{
  0%,100%{opacity:1;transform:scale(1);}
  50%{opacity:.45;transform:scale(.82);}
}

/* 顶部条：默认隐藏，移动端启用 */
.topbar{display:none;}
.topbar-mark{width:18px;height:18px;flex:0 0 18px;background:var(--maple);clip-path:var(--leaf);}
.nav-toggle{position:relative;width:46px;height:40px;border-radius:2px;}
.nav-toggle-bars,
.nav-toggle-bars::before,
.nav-toggle-bars::after{
  content:"";position:absolute;left:0;width:20px;height:2px;background:#fff;
  transition:transform .2s ease,opacity .2s ease,background .2s ease;
}
.nav-toggle-bars{top:0;}
.nav-toggle-bars::before{top:-6px;left:0;}
.nav-toggle-bars::after{top:6px;left:0;}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars{background:transparent;}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before{transform:translateY(6px) rotate(45deg);}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after{transform:translateY(-6px) rotate(-45deg);}

.nav-scrim{display:none;}

/* 滚动进度 */
.scroll-progress{
  position:fixed;top:0;left:0;right:0;height:3px;z-index:120;
  pointer-events:none;background:rgba(6,18,38,.08);
}
.scroll-progress-bar{
  display:block;width:0;height:100%;background:var(--maple);
  transition:width .1s linear;
}

/* 提示条 */
.toast{
  position:fixed;left:50%;bottom:24px;z-index:200;
  max-width:min(420px,90vw);
  padding:.85rem 1.15rem;
  background:var(--navy);color:var(--mist);
  border:2px solid var(--maple);border-radius:2px;
  font-size:.875rem;line-height:1.6;
  box-shadow:6px 6px 0 0 rgba(6,18,38,.3);
  opacity:0;transform:translate(-50%,140%);
  transition:transform .24s ease,opacity .24s ease;
  pointer-events:none;
}
.toast[data-visible]{opacity:1;transform:translate(-50%,0);}

/* ---------- 6. 面包屑 ---------- */
.breadcrumb{
  font-family:var(--font-mono);font-size:.75rem;letter-spacing:.06em;
  color:var(--slate);
}
.breadcrumb ol{display:flex;flex-wrap:wrap;align-items:center;gap:8px;}
.breadcrumb li{display:flex;align-items:center;}
.breadcrumb li+li::before{content:"/";margin-right:8px;color:var(--line-strong);}
.breadcrumb a{text-decoration:none;border-bottom:1px solid transparent;transition:border-color .16s ease,color .16s ease;}
.breadcrumb a:hover{color:var(--maple);border-bottom-color:var(--maple);}
.breadcrumb [aria-current="page"]{color:var(--ink);}

/* ---------- 7. 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.5rem;
  padding:.85rem 1.35rem;
  font-size:.9375rem;font-weight:600;line-height:1;letter-spacing:.03em;
  text-decoration:none;cursor:pointer;border-radius:2px;
  border:2px solid var(--navy);
  background:var(--mist);color:var(--navy);
  box-shadow:4px 4px 0 0 var(--navy);
  transition:transform .16s ease,box-shadow .16s ease,background .16s ease,color .16s ease,border-color .16s ease;
}
.btn:hover{transform:translate(-1px,-1px);box-shadow:6px 6px 0 0 var(--navy);}
.btn:active{transform:translate(2px,2px);box-shadow:1px 1px 0 0 var(--navy);}
.btn--primary{background:var(--maple);border-color:var(--maple);color:#fff;box-shadow:4px 4px 0 0 var(--navy);}
.btn--primary:hover{box-shadow:6px 6px 0 0 var(--navy);}
.btn--ghost{background:transparent;border-color:var(--line-strong);color:var(--navy);box-shadow:none;}
.btn--ghost:hover{transform:translateY(-1px);box-shadow:3px 3px 0 0 var(--line-strong);border-color:var(--navy);}
.btn--quiet{background:transparent;border-color:transparent;box-shadow:none;padding:.6rem .4rem;color:var(--maple);}
.btn--quiet:hover{transform:none;box-shadow:none;background:var(--maple-soft);}
.btn--mono{font-family:var(--font-mono);font-size:var(--fs-mono);letter-spacing:.06em;}
.btn-row{display:flex;flex-wrap:wrap;gap:14px;align-items:center;}

/* ---------- 8. 标签 ---------- */
.tag-row{display:flex;flex-wrap:wrap;gap:8px;}
.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:.32rem .6rem;
  font-family:var(--font-mono);font-size:.75rem;letter-spacing:.06em;line-height:1.4;
  border:1px solid var(--line-strong);border-radius:2px;
  background:var(--mist);color:var(--navy);
  text-decoration:none;
  transition:background .16s ease,color .16s ease,border-color .16s ease,transform .16s ease;
}
a.tag:hover{background:var(--navy);color:#fff;border-color:var(--navy);transform:translateY(-1px);}
.tag--maple{background:var(--maple);border-color:var(--maple);color:#fff;}
a.tag--maple:hover{background:#b52218;border-color:#b52218;color:#fff;}
.tag--teal{background:var(--teal);border-color:var(--teal);color:#fff;}
.tag--gold{background:var(--gold);border-color:var(--gold);color:var(--navy);}
.tag--soft{background:var(--maple-soft);border-color:transparent;color:var(--maple);}

/* ---------- 9. 卡片与面板 ---------- */
.card{
  position:relative;
  padding:22px;
  background:#fff;
  border:2px solid var(--navy);border-radius:2px;
  box-shadow:6px 6px 0 0 rgba(11,31,58,.12);
  transition:transform .18s ease,box-shadow .18s ease,border-color .18s ease;
}
.card:hover{transform:translate(-2px,-2px);box-shadow:9px 9px 0 0 rgba(11,31,58,.18);border-color:var(--maple);}
.card-title{font-size:1.25rem;font-weight:600;line-height:1.4;letter-spacing:-.01em;}
.card-title a{text-decoration:none;}
.card-meta{
  font-family:var(--font-mono);font-size:.75rem;letter-spacing:.08em;
  color:var(--slate);text-transform:uppercase;
}
.card-body{margin-top:12px;color:#334155;}
.card--flat{box-shadow:none;}
.card--flat:hover{transform:none;box-shadow:none;}
.card--accent{border-left:8px solid var(--maple);}
.section--navy .card{background:#12294a;border-color:rgba(248,250,252,.24);color:rgba(248,250,252,.82);box-shadow:6px 6px 0 0 rgba(6,18,38,.6);}
.section--navy .card-title{color:#fff;}

.panel{
  padding:18px 20px;
  background:var(--grey);
  border-left:4px solid var(--maple);border-radius:2px;
}

/* ---------- 10. 时间轴 / 数据 ---------- */
.timeline{position:relative;padding-left:26px;}
.timeline::before{
  content:"";position:absolute;left:6px;top:8px;bottom:8px;width:2px;
  background:repeating-linear-gradient(180deg,var(--line-strong) 0 6px,transparent 6px 13px);
}
.tl-item{position:relative;padding-bottom:30px;}
.tl-item:last-child{padding-bottom:0;}
.tl-item::before{
  content:"";position:absolute;left:-26px;top:7px;
  width:12px;height:12px;border-radius:50%;
  background:var(--mist);border:3px solid var(--maple);
}
.tl-date{
  font-family:var(--font-mono);font-size:.75rem;letter-spacing:.1em;
  color:var(--maple);text-transform:uppercase;
}
.tl-title{font-size:1.0625rem;font-weight:600;line-height:1.5;margin-top:2px;}

.stat{border-top:3px solid var(--navy);padding-top:12px;}
.stat-value{
  display:block;font-family:var(--font-mono);font-size:2rem;font-weight:600;
  letter-spacing:-.02em;line-height:1.2;
}
.stat-label{display:block;margin-top:4px;font-size:var(--fs-note);color:var(--slate);}
.stat--teal{border-top-color:var(--teal);}
.stat--gold{border-top-color:var(--gold);}
.stat--maple{border-top-color:var(--maple);}

/* ---------- 11. 手风琴 ---------- */
.acc{border:2px solid var(--navy);border-radius:2px;background:#fff;overflow:hidden;}
.acc-item+.acc-item{border-top:1px solid var(--line);}
.acc-item summary{
  display:flex;align-items:flex-start;gap:14px;
  padding:18px 20px;cursor:pointer;
  font-size:1.0625rem;font-weight:600;line-height:1.55;
  list-style:none;
}
.acc-item summary::-webkit-details-marker{display:none;}
.acc-item summary::after{
  content:"+";margin-left:auto;
  font-family:var(--font-mono);font-size:1.25rem;line-height:1;color:var(--maple);
  transition:transform .2s ease;
}
.acc-item[open] summary::after{content:"–";}
.acc-item[open] summary{background:var(--maple-soft);}
.acc-index{
  flex:0 0 auto;font-family:var(--font-mono);font-size:.75rem;
  color:var(--slate);padding-top:5px;
}
.acc-body{padding:4px 20px 20px 20px;color:#334155;}
.acc-body>*+*{margin-top:.85rem;}

/* ---------- 12. 图片容器（页面阶段放图） ---------- */
.figure{margin:0;}
.figure-media{
  position:relative;overflow:hidden;
  border:2px solid var(--navy);border-radius:2px;
  aspect-ratio:16/9;
  background-color:var(--grey);
  background-image:
    linear-gradient(rgba(11,31,58,.09) 1px,transparent 1px),
    linear-gradient(90deg,rgba(11,31,58,.09) 1px,transparent 1px);
  background-size:24px 24px;
}
.figure-media>img{width:100%;height:100%;object-fit:cover;object-position:center;}
.figure--wide .figure-media{aspect-ratio:21/9;}
.figure--tall .figure-media{aspect-ratio:3/4;}
.figure--square .figure-media{aspect-ratio:1/1;}
.figure-caption{
  margin-top:10px;font-family:var(--font-mono);font-size:.75rem;
  letter-spacing:.04em;color:var(--slate);
}

/* ---------- 13. 滚动显现 ---------- */
.js [data-reveal]{
  opacity:0;transform:translateY(16px);
  transition:opacity .55s ease,transform .55s ease;
}
.js [data-reveal].is-visible{opacity:1;transform:none;}

/* ---------- 14. 页脚 ---------- */
.site-footer{
  background:var(--navy);
  color:rgba(248,250,252,.78);
  border-top:6px solid var(--maple);
  padding:56px 0 26px;
}
.footer-grid{
  width:100%;max-width:var(--wrap);margin:0 auto;padding:0 24px;
  display:grid;grid-template-columns:1.1fr .9fr 1.4fr;gap:40px;
}
.footer-brand{font-size:1.5rem;font-weight:600;color:#fff;letter-spacing:-.01em;line-height:1.3;}
.footer-domain{
  margin-top:6px;font-family:var(--font-mono);font-size:.8125rem;
  letter-spacing:.1em;color:var(--gold);word-break:break-all;
}
.footer-note{margin-top:14px;font-size:.8125rem;line-height:1.75;color:rgba(248,250,252,.55);max-width:34ch;}
.footer-heading{
  display:flex;align-items:center;gap:10px;
  margin-bottom:16px;
  font-family:var(--font-mono);font-size:.6875rem;font-weight:500;
  letter-spacing:.2em;text-transform:uppercase;color:#fff;
}
.footer-heading::before{content:"";width:16px;height:2px;background:var(--maple);}
.footer-nav-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px 18px;}
.footer-nav-list a{
  font-size:.9375rem;text-decoration:none;color:rgba(248,250,252,.78);
  border-bottom:1px solid transparent;padding-bottom:2px;
  transition:color .16s ease,border-color .16s ease;
}
.footer-nav-list a:hover{color:#fff;border-bottom-color:var(--maple);}
.contact-list{display:grid;gap:14px;}
.contact-item{display:grid;gap:2px;}
.contact-key{
  font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.16em;
  text-transform:uppercase;color:rgba(248,250,252,.45);
}
.contact-val{
  font-family:var(--font-mono);font-size:.875rem;line-height:1.65;
  color:var(--mist);word-break:break-word;
}
.footer-legal{
  max-width:var(--wrap);margin:44px auto 0;padding:20px 24px 0;
  border-top:1px solid var(--line-light);
  display:flex;flex-wrap:wrap;gap:12px 24px;align-items:center;justify-content:space-between;
  font-family:var(--font-mono);font-size:.8125rem;letter-spacing:.06em;
  color:rgba(248,250,252,.55);
}
.footer-icp{display:inline-flex;align-items:center;gap:8px;}
.footer-icp::before{content:"";width:10px;height:10px;background:var(--maple);clip-path:var(--leaf);}
.footer-disclaimer{
  max-width:var(--wrap);margin:14px auto 0;padding:0 24px;
  font-size:.75rem;line-height:1.7;color:rgba(248,250,252,.42);
}

/* ---------- 15. 响应式：平板 ---------- */
@media (max-width:1100px){
  .grid--4{grid-template-columns:repeat(2,minmax(0,1fr));}
}
@media (max-width:900px){
  .grid--3{grid-template-columns:repeat(2,minmax(0,1fr));}
  .footer-grid{grid-template-columns:1fr 1fr;gap:34px;}
  .footer-col--contact{grid-column:1 / -1;}
}
@media (max-width:640px){
  .grid--2,.grid--3,.grid--4{grid-template-columns:minmax(0,1fr);}
  .wrap{padding:0 18px;}
  .section{padding:48px 0;}
  .section--wide{padding:60px 0;}
  .footer-grid{grid-template-columns:minmax(0,1fr);gap:30px;padding:0 18px;}
  .footer-nav-list{grid-template-columns:repeat(2,minmax(0,1fr));}
  .footer-legal{padding:18px 18px 0;font-size:.75rem;}
  .footer-disclaimer{padding:0 18px;}
  .btn{width:100%;}
  .btn-row{gap:10px;}
}

/* ---------- 16. 响应式：移动端抽屉 ---------- */
@media (max-width:1023.98px){
  .site-header{position:sticky;top:0;z-index:90;}
  .topbar{
    display:flex;align-items:center;justify-content:space-between;gap:12px;
    height:58px;padding:0 14px;
    background:var(--navy);
    border-bottom:2px solid var(--maple);
  }
  .topbar-brand{
    display:flex;align-items:center;gap:9px;
    color:var(--mist);text-decoration:none;
    font-size:1rem;font-weight:600;letter-spacing:.02em;
  }
  .topbar-actions{display:flex;align-items:center;gap:10px;}
  .topbar-version{
    padding:6px 9px;
    font-family:var(--font-mono);font-size:.75rem;letter-spacing:.06em;
    color:rgba(248,250,252,.72);text-decoration:none;
    border:1px solid rgba(248,250,252,.26);border-radius:2px;
    transition:color .16s ease,border-color .16s ease;
  }
  .topbar-version:hover{color:var(--gold);border-color:var(--gold);}
  .nav-toggle{
    display:block;cursor:pointer;
    background:var(--maple);
    border:2px solid rgba(255,255,255,.26);
    box-shadow:2px 2px 0 0 rgba(6,18,38,.9);
  }
  .nav-toggle:active{transform:translate(1px,1px);box-shadow:none;}
  .nav-toggle .nav-toggle-bars{position:absolute;left:50%;top:50%;margin:-1px 0 0 -10px;}

  .rail{
    position:static;width:auto;height:auto;
    padding:0;border:0;background:none;overflow:visible;
    display:block;
  }
  .rail::before,.rail::after{display:none;}
  .brand,.rail-vertical{display:none;}

  .rail-nav{
    position:fixed;top:0;left:0;bottom:0;z-index:100;
    width:min(320px,86vw);
    margin:0;padding:22px 18px 24px;
    background:var(--navy);
    border-right:3px solid var(--maple);
    box-shadow:10px 0 0 0 rgba(6,18,38,.35);
    overflow-y:auto;
    display:flex;flex-direction:column;
    transform:translateX(-104%);
    transition:transform .26s cubic-bezier(.2,.75,.2,1);
  }
  .rail-nav[data-open]{transform:none;}
  .rail-nav .nav-list{gap:4px;}
  .rail-nav .nav-link{
    padding:13px 12px 13px 10px;
    font-size:1rem;
    color:rgba(248,250,252,.8);
    border-left:3px solid transparent;
  }
  .rail-nav .rail-foot{margin-top:auto;padding-top:20px;}
  .rail-nav .rail-collect,.rail-nav .rail-version{width:auto;}

  .nav-scrim{
    display:block;position:fixed;inset:0;z-index:95;
    background:rgba(6,18,38,.62);
    opacity:0;visibility:hidden;
    transition:opacity .22s ease,visibility .22s ease;
  }
  .nav-scrim[data-open]{opacity:1;visibility:visible;}
  body.is-nav-open{overflow:hidden;}
  .toast{left:18px;right:18px;bottom:18px;transform:translateY(140%);max-width:none;}
  .toast[data-visible]{transform:translateY(0);}
}

/* ---------- 17. 响应式：桌面轨道 ---------- */
@media (min-width:1024px){
  body{padding-left:var(--rail-w);}
  .topbar{display:none;}
  .nav-scrim{display:none;}
  .scroll-progress{left:var(--rail-w);}
  .toast{left:calc(var(--rail-w) / 2 + 50%);}
}

/* ---------- 18. 动效降级 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto;}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  .update-dot{animation:none;}
  .js [data-reveal]{opacity:1;transform:none;}
  .nav-link:hover,.nav-link:focus-visible{transform:none;}
  .card:hover{transform:none;}
  .btn:hover,.btn:active{transform:none;}
}