@import url('https://fonts.googleapis.com/css2?family=Fira+Code:wght@300;400;500;600;700&family=Share+Tech+Mono&display=swap');

:root{
  --bg:#e4edf5;
  --bg-lo:#d5e3ef;
  --bg-hi:#eef5fb;
  --ink:#171f26;
  --ink-2:#41525f;
  --pink:#f5e0e8;
  --pink-lo:#ecd3de;
  --blue:#c8e0f4;
  --up:-6px -6px 16px rgba(255,255,255,.95), 6px 6px 18px rgba(23,31,38,.14);
  --up-sm:-3px -3px 8px rgba(255,255,255,.9), 3px 3px 9px rgba(23,31,38,.12);
  --in:inset -3px -3px 8px rgba(255,255,255,.92), inset 3px 3px 9px rgba(23,31,38,.15);
  --r:0px;
  --r-ctl:12px;
}

*{box-sizing:border-box}

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

body{
  margin:0;
  min-height:100vh;
  background:var(--bg);
  background-image:radial-gradient(rgba(23,31,38,.10) 1px, transparent 1px);
  background-size:16px 16px;
  color:var(--ink);
  font-family:'Fira Code', ui-monospace, SFMono-Regular, 'PingFang SC', 'Microsoft YaHei', monospace;
  font-size:16px;
  line-height:1.75;
  letter-spacing:.01em;
  overflow-x:hidden;
}

h1,h2,h3,h4{
  font-family:'Share Tech Mono', 'Fira Code', ui-monospace, 'PingFang SC', monospace;
  font-weight:400;
  line-height:1.35;
  letter-spacing:.03em;
}

img{max-width:100%;height:auto;display:block}
a{color:var(--ink)}
p{margin:0 0 .9em}
p:last-child{margin-bottom:0}

/* ---------- 框架 ---------- */
.app{display:flex;min-height:100vh}

.stage{
  flex:1 1 auto;
  min-width:0;
  margin-left:214px;
  display:flex;
  flex-direction:column;
}

/* ---------- 左侧固定竖排 ---------- */
.rail{
  position:fixed;
  top:0;left:0;bottom:0;
  width:214px;
  z-index:30;
  display:flex;
  flex-direction:column;
  gap:14px;
  padding:20px 16px 26px;
  overflow-y:auto;
  background:linear-gradient(160deg, var(--bg-hi), var(--bg-lo));
  box-shadow:8px 0 22px rgba(23,31,38,.10);
}

.mark{
  width:46px;height:46px;
  flex:0 0 auto;
  display:flex;align-items:center;justify-content:center;
  border-radius:14px;
  text-decoration:none;
  background:linear-gradient(145deg, var(--bg-hi), var(--bg-lo));
  box-shadow:var(--up);
  overflow:hidden;
}
.mark:active{box-shadow:var(--in);transform:scale(.97)}
.mark-img{width:46px;height:46px;object-fit:cover}
.mark-txt{
  font-family:'Share Tech Mono', monospace;
  font-size:20px;
  color:var(--ink);
}

.rail-top{display:flex;flex-direction:column;gap:2px}
.rail-h{
  margin:0;
  font-size:15px;
  line-height:1.3;
  word-break:break-word;
}
.subtitle{
  margin:0;
  font-size:12px;
  letter-spacing:.3em;
  color:var(--ink-2);
}

.rail-nav{display:flex;flex-direction:column;gap:8px;margin-top:4px}

.rail-link{
  display:flex;
  align-items:center;
  gap:10px;
  min-height:44px;
  padding:9px 11px;
  border-radius:var(--r-ctl);
  text-decoration:none;
  font-size:15px;
  line-height:1.3;
  color:var(--ink);
  background:linear-gradient(145deg, var(--bg-hi), var(--bg-lo));
  box-shadow:var(--up);
  transition:box-shadow .15s ease, transform .15s ease;
}
.rail-link:hover{box-shadow:var(--in)}
.rail-link:active{box-shadow:var(--in);transform:scale(.97)}
.ico{
  flex:0 0 auto;
  width:20px;height:20px;
  display:flex;align-items:center;justify-content:center;
  border-radius:8px;
  font-size:13px;
  color:var(--ink-2);
  background:var(--pink);
  box-shadow:var(--up-sm);
}
.rail-txt{min-width:0}

/* ---------- 顶部细条 ---------- */
.ticker{
  overflow:hidden;
  background:var(--ink);
  color:#cfe2f0;
  font-size:13px;
  line-height:1;
  letter-spacing:.18em;
  padding:9px 0;
}
.ticker-in{
  display:flex;
  gap:24px;
  white-space:nowrap;
  width:max-content;
  animation:slide 38s linear infinite;
}
.ticker-set{display:inline-block}
.dot{font-style:normal;color:#8fa9bb;padding:0 4px}
@keyframes slide{
  from{transform:translateX(0)}
  to{transform:translateX(-50%)}
}

/* ---------- 正文 ---------- */
.stage-main{
  flex:1 1 auto;
  padding:0 26px 44px;
}

.paper{
  max-width:900px;
  margin:0 auto;
}

.hero{
  position:relative;
  min-height:45vh;
  display:flex;
  align-items:center;
  padding:34px 30px;
  margin:0 0 26px;
  overflow:hidden;
  border-radius:var(--r);
  background:linear-gradient(140deg, var(--blue), var(--bg-hi) 55%, var(--pink));
  box-shadow:var(--up);
  isolation:isolate;
}
.hero-media{position:absolute;inset:0;z-index:0;overflow:hidden}
.hero-img{
  width:100%;height:100%;
  object-fit:cover;
  transform:scale(1.08);
  will-change:transform;
}
.hero-vail{
  position:absolute;inset:0;z-index:1;
  background:radial-gradient(circle at 82% 26%, rgba(245,224,232,.85), transparent 58%);
}
.hero--img .hero-vail{
  background:linear-gradient(92deg, rgba(23,31,38,.78), rgba(23,31,38,.34) 60%, rgba(23,31,38,.06));
}
.hero-txt{position:relative;z-index:2;max-width:720px}
.hero h1{
  margin:0;
  font-size:clamp(26px, 4.4vw, 44px);
  color:var(--ink);
}
.hero--img h1{
  color:#f2f7fb;
  text-shadow:0 2px 14px rgba(0,0,0,.45);
}

.paper > div{
  padding:22px 22px 24px;
  margin:0 0 22px;
  border-radius:var(--r);
  background:linear-gradient(145deg, var(--bg-hi), var(--bg-lo));
  box-shadow:var(--up);
  scroll-margin-top:22px;
  overflow-wrap:break-word;
}
.paper > div:nth-of-type(even){
  background:linear-gradient(145deg, #f6ebf0, #e8dbe4);
}

.paper h2{
  margin:0 0 .55em;
  font-size:22px;
  scroll-margin-top:22px;
}
.paper h3{
  margin:1.2em 0 .45em;
  font-size:18px;
}
.paper h2 + p,
.paper h3 + p{margin-top:-.15em}

.paper a{
  color:var(--ink);
  text-decoration:underline;
  text-decoration-thickness:1px;
  text-underline-offset:3px;
}
.paper a:hover{color:#0d5f8a}

.paper ul,.paper ol{margin:0 0 1em;padding-left:1.35em}
.paper li{margin:.25em 0}
.paper li::marker{color:var(--ink-2)}
.paper strong{font-weight:600}
.paper img{margin:.9em 0;border-radius:var(--r)}
.paper blockquote{
  margin:1em 0;
  padding:12px 16px;
  border-radius:var(--r-ctl);
  background:var(--bg);
  box-shadow:var(--in);
  color:var(--ink-2);
}
.paper code,.paper pre{
  font-family:'Fira Code', ui-monospace, monospace;
  font-size:15px;
}
.paper pre{
  overflow-x:auto;
  padding:14px;
  border-radius:var(--r-ctl);
  background:var(--bg);
  box-shadow:var(--in);
}

/* ---------- 页脚 ---------- */
.foot{
  margin-top:auto;
  display:grid;
  grid-template-columns:1.5fr 1.1fr 1.2fr;
  gap:24px;
  padding:32px 26px 16px;
  background:linear-gradient(160deg, var(--bg-hi), var(--bg-lo));
  box-shadow:0 -8px 24px rgba(23,31,38,.09);
}
.foot div{min-width:0}
.foot-h{
  margin:0 0 .6em;
  font-size:17px;
}
.foot-desc{font-size:15px;color:var(--ink-2);line-height:1.65}

.foot-nav dl{
  margin:0;
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:6px 10px;
}
.foot-nav dt{
  grid-column:1 / -1;
  font-size:13px;
  letter-spacing:.22em;
  color:var(--ink-2);
  padding-left:2px;
}
.foot-nav dd{margin:0}
.foot-nav dd a{
  display:flex;
  align-items:center;
  min-height:40px;
  padding:6px 10px;
  border-radius:10px;
  font-size:15px;
  text-decoration:none;
  color:var(--ink);
  background:linear-gradient(145deg, var(--bg-hi), var(--bg-lo));
  box-shadow:var(--up-sm);
  transition:box-shadow .15s ease, transform .15s ease;
}
.foot-nav dd a:hover{box-shadow:var(--in)}
.foot-nav dd a:active{transform:scale(.97)}

.sub{display:flex;flex-wrap:wrap;gap:10px;align-items:center}
.sub-lab{
  width:100%;
  font-size:13px;
  letter-spacing:.22em;
  color:var(--ink-2);
}
.sub-in{
  flex:1 1 130px;
  min-height:44px;
  padding:0 13px;
  border:0;
  border-radius:var(--r-ctl);
  background:var(--bg);
  box-shadow:var(--in);
  font:inherit;
  font-size:15px;
  color:var(--ink);
}
.sub-in:focus{outline:2px solid #9dc4e2;outline-offset:1px}
.sub-btn{
  min-height:44px;
  padding:0 20px;
  border:0;
  border-radius:var(--r-ctl);
  background:linear-gradient(145deg, var(--pink), var(--pink-lo));
  color:var(--ink);
  font:inherit;
  font-size:15px;
  cursor:pointer;
  box-shadow:var(--up);
  transition:box-shadow .15s ease, transform .15s ease;
}
.sub-btn:hover{box-shadow:var(--in)}
.sub-btn:active{transform:scale(.96);box-shadow:var(--in)}

.foot-base{
  grid-column:1 / -1;
  display:flex;
  flex-wrap:wrap;
  gap:10px 18px;
  align-items:center;
  justify-content:center;
  margin-top:6px;
  padding-top:14px;
  border-top:1px dashed rgba(23,31,38,.18);
  font-size:14px;
  color:var(--ink-2);
}
.copy{margin:0}
.to-top{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  padding:0 14px;
  border-radius:10px;
  text-decoration:none;
  color:var(--ink);
  background:linear-gradient(145deg, var(--bg-hi), var(--bg-lo));
  box-shadow:var(--up-sm);
}
.to-top:active{box-shadow:var(--in)}

/* ---------- 动效 ---------- */
.rv{
  opacity:0;
  transform:translateY(16px);
  transition:opacity .6s ease, transform .6s ease;
}
.rv.in{opacity:1;transform:none}

@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  .ticker-in{animation:none}
  .rv{opacity:1;transform:none;transition:none}
  .hero-img{transform:none}
}

/* ---------- 断点 ---------- */
@media (max-width:1000px){
  .foot{grid-template-columns:1fr 1fr}
  .foot-brand{grid-column:1 / -1}
  .foot-sub{grid-column:1 / -1}
}

@media (max-width:860px){
  .app{display:block}
  .rail{
    position:sticky;
    top:0;left:auto;bottom:auto;
    width:auto;
    flex-direction:row;
    align-items:center;
    gap:10px;
    padding:8px 12px;
    overflow:hidden;
    box-shadow:0 6px 18px rgba(23,31,38,.12);
  }
  .mark{width:42px;height:42px;border-radius:12px}
  .mark-img{width:42px;height:42px}
  .rail-top{flex:0 0 auto;max-width:34vw}
  .rail-h{font-size:14px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
  .rail-top .subtitle{display:none}
  .rail-nav{
    flex-direction:row;
    gap:8px;
    margin-top:0;
    flex:1 1 auto;
    overflow-x:auto;
    overflow-y:hidden;
    scrollbar-width:none;
    padding-bottom:2px;
  }
  .rail-nav::-webkit-scrollbar{display:none}
  .rail-link{flex:0 0 auto;white-space:nowrap;min-height:44px;padding:8px 12px;font-size:14px}
  .rail-txt{white-space:nowrap}

  .stage{margin-left:0}
  .ticker{font-size:12px;padding:7px 0;letter-spacing:.14em}
  .stage-main{padding:0 14px 30px}
  .hero{min-height:42vh;padding:26px 18px;margin-bottom:18px}
  .paper > div{padding:18px 16px 20px;margin-bottom:16px;scroll-margin-top:78px}
  .paper h2{font-size:20px;scroll-margin-top:78px}
  .foot{grid-template-columns:1fr;padding:24px 16px 14px;gap:18px}
  .foot-brand,.foot-sub{grid-column:auto}
}

@media (max-width:420px){
  .foot-nav dl{grid-template-columns:1fr}
  .hero h1{font-size:26px}
}

button[aria-expanded]{min-width:44px;min-height:44px}