@import url('https://fonts.googleapis.com/css2?family=Newsreader:wght@400;500;600;700&family=Roboto:wght@300;400;500;700&display=swap');

:root{
  --red:#ff0000;
  --violet:#8b00ff;
  --ink:#261717;
  --paper:#f7eeee;
  --muted:#d3bcc1;
  --glass:rgba(255,255,255,.08);
  --line:rgba(255,255,255,.2);
  --serif:"Newsreader",Georgia,"Songti SC","Noto Serif SC",serif;
  --sans:"Roboto","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
}

*,*::before,*::after{box-sizing:border-box}

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

body{
  margin:0;
  min-height:100vh;
  color:var(--paper);
  font:400 17px/1.75 var(--sans);
  background:
    radial-gradient(1100px 620px at 84% -12%,rgba(139,0,255,.42),transparent 62%),
    radial-gradient(920px 520px at -6% 18%,rgba(255,0,0,.32),transparent 58%),
    radial-gradient(720px 460px at 52% 108%,rgba(139,0,255,.22),transparent 60%),
    var(--ink);
  background-attachment:fixed;
}

body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:0;
  pointer-events:none;
  background-image:radial-gradient(rgba(255,255,255,.08) 1px,transparent 1px);
  background-size:22px 22px;
  -webkit-mask-image:linear-gradient(180deg,#000 0%,rgba(0,0,0,.35) 45%,transparent 80%);
  mask-image:linear-gradient(180deg,#000 0%,rgba(0,0,0,.35) 45%,transparent 80%);
}

a{transition:color .22s ease,background .22s ease,border-color .22s ease,transform .22s ease,box-shadow .22s ease}

:focus-visible{outline:2px solid #ff7d7d;outline-offset:2px}

img{max-width:100%;height:auto}

::-webkit-scrollbar{height:8px;width:8px}
::-webkit-scrollbar-thumb{background:rgba(255,255,255,.22)}
::-webkit-scrollbar-track{background:transparent}

/* 顶栏 */
.topbar{
  position:relative;
  z-index:3;
  display:grid;
  grid-template-columns:1fr auto 1fr;
  align-items:center;
  gap:10px;
  padding:10px 20px;
  background:rgba(255,255,255,.06);
  border-bottom:1px solid var(--line);
  -webkit-backdrop-filter:blur(15px);
  backdrop-filter:blur(15px);
  box-shadow:0 20px 50px -40px #000;
}

.tier{display:flex;flex-wrap:nowrap;list-style:none;margin:0;padding:0;gap:2px}
.menu-a .tier{justify-content:flex-end}
.menu-b .tier{justify-content:flex-start}
.menu ul{overflow-x:auto;scrollbar-width:none}
.menu ul::-webkit-scrollbar{display:none}

.menu a{
  display:flex;
  align-items:center;
  min-height:44px;
  padding:0 10px;
  font-size:16px;
  color:var(--muted);
  text-decoration:none;
  white-space:nowrap;
  border-bottom:1px solid transparent;
}
.menu a:hover{color:#fff;background:rgba(255,255,255,.1);border-bottom-color:var(--red)}

.brand{
  display:inline-flex;
  align-items:center;
  gap:8px;
  justify-self:center;
  padding:8px 12px;
  min-height:44px;
  color:#fff;
  text-decoration:none;
  font-family:var(--serif);
  font-size:1.2rem;
  letter-spacing:.08em;
  white-space:nowrap;
  text-shadow:0 2px 18px rgba(255,0,0,.5);
}
.brand:hover{transform:translateY(-1px)}
.logo{display:block;width:34px;height:34px;object-fit:contain}
.logo-mark{font-size:22px;line-height:1}

/* 粘性锚点条 */
.stickbar{
  position:sticky;
  top:0;
  z-index:20;
  background:rgba(38,23,23,.6);
  border-bottom:1px solid var(--line);
  -webkit-backdrop-filter:blur(18px) saturate(140%);
  backdrop-filter:blur(18px) saturate(140%);
  box-shadow:0 16px 34px -26px #000;
}

.anchors ul{
  display:flex;
  gap:4px;
  overflow-x:auto;
  scrollbar-width:none;
  list-style:none;
  margin:0;
  padding:5px 16px;
}
.anchors ul::-webkit-scrollbar{display:none}

.anchors a{
  display:flex;
  align-items:center;
  min-height:44px;
  padding:0 12px;
  font-size:16px;
  color:var(--muted);
  text-decoration:none;
  white-space:nowrap;
  border:1px solid transparent;
}
.anchors a:hover,
.anchors a.on{
  color:#fff;
  background:rgba(255,255,255,.12);
  border-color:var(--line);
  box-shadow:inset 0 0 24px rgba(255,0,0,.22);
}

/* 主体骨架 */
.shell{
  position:relative;
  z-index:1;
  display:grid;
  grid-template-columns:236px minmax(0,1fr);
  gap:34px;
  max-width:1240px;
  margin:0 auto;
  padding:32px 20px 56px;
}

.side{align-self:start;position:sticky;top:78px}

.side-h{
  margin:0 0 10px;
  font-size:16px;
  letter-spacing:.22em;
  color:var(--muted);
}

.side-list{
  list-style:none;
  margin:0;
  padding:10px;
  display:grid;
  gap:4px;
  background:var(--glass);
  border:1px solid var(--line);
  -webkit-backdrop-filter:blur(15px);
  backdrop-filter:blur(15px);
  box-shadow:0 26px 50px -38px #000,inset 0 1px 0 rgba(255,255,255,.22);
}

.side-list a{
  display:flex;
  align-items:center;
  min-height:44px;
  padding:0 10px;
  font-size:16px;
  color:var(--muted);
  text-decoration:none;
  border-left:2px solid transparent;
  background:rgba(255,255,255,.03);
}
.side-list a:hover{
  color:#fff;
  background:rgba(255,255,255,.13);
  border-left-color:var(--red);
  transform:translateX(3px);
  box-shadow:0 8px 22px -16px #000;
}

main{min-width:0}

/* Hero */
.hero{
  position:relative;
  display:flex;
  align-items:center;
  gap:22px;
  min-height:70vh;
  padding:44px 28px;
  overflow:hidden;
  background:rgba(255,255,255,.07);
  border:1px solid var(--line);
  -webkit-backdrop-filter:blur(15px);
  backdrop-filter:blur(15px);
  box-shadow:0 50px 90px -60px #000,inset 0 1px 0 rgba(255,255,255,.3);
}

.hero::before{
  content:"";
  position:absolute;
  width:440px;
  height:440px;
  right:-140px;
  top:-160px;
  border-radius:50%;
  pointer-events:none;
  background:radial-gradient(circle,rgba(255,0,0,.6),rgba(139,0,255,.4) 46%,transparent 72%);
  filter:blur(20px);
}

.hero::after{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background-image:radial-gradient(rgba(255,255,255,.16) 1px,transparent 1px);
  background-size:20px 20px;
  -webkit-mask-image:radial-gradient(62% 62% at 26% 44%,#000,transparent);
  mask-image:radial-gradient(62% 62% at 26% 44%,#000,transparent);
}

.hero > *{position:relative;z-index:1}

.mark{flex:0 0 auto;line-height:0;filter:drop-shadow(0 0 18px rgba(255,0,0,.55))}

.hero-txt{flex:1 1 auto;min-width:0}

.hero h1{
  margin:0;
  font-family:var(--serif);
  font-weight:600;
  font-size:clamp(2rem,5vw,3.3rem);
  line-height:1.24;
  letter-spacing:.02em;
  color:#fff;
  overflow-wrap:anywhere;
  text-shadow:0 3px 34px rgba(255,0,0,.4);
}

.lede{
  margin:16px 0 0;
  max-width:56ch;
  font-size:17px;
  color:var(--muted);
}

/* 正文面板 */
.sheet{
  margin-top:32px;
  padding:28px 30px 42px;
  background:rgba(255,255,255,.06);
  border:1px solid var(--line);
  -webkit-backdrop-filter:blur(15px);
  backdrop-filter:blur(15px);
  box-shadow:0 50px 100px -70px #000,inset 0 1px 0 rgba(255,255,255,.2);
}

.sheet-h{
  margin:0;
  font-family:var(--serif);
  font-size:1.45rem;
  font-weight:600;
  letter-spacing:.1em;
  color:#fff;
}

.sheet hr{
  border:0;
  height:1px;
  margin:14px 0 24px;
  background:linear-gradient(90deg,var(--red),var(--violet) 48%,rgba(255,255,255,0));
}

.sheet h2{
  margin:2.2rem 0 .6rem;
  font-family:var(--serif);
  font-weight:600;
  font-size:1.5rem;
  line-height:1.34;
  color:#fff;
}

.sheet h3{
  margin:1.6rem 0 .5rem;
  font-size:1.15rem;
  color:#fff;
}

.sheet p{margin:0 0 1rem;color:#f0e2e5}
.sheet strong{color:#fff}
.sheet a{color:#ff9b9b;text-decoration:underline;text-underline-offset:3px}
.sheet a:hover{color:#fff}
.sheet ul,.sheet ol{padding-left:1.25rem;color:#f0e2e5}
.sheet li{margin:.35rem 0}

.sheet blockquote{
  margin:1.4rem 0;
  padding:14px 18px;
  border-left:3px solid var(--red);
  background:rgba(255,255,255,.07);
  box-shadow:inset 0 0 40px rgba(139,0,255,.14);
}

.sheet table{width:100%;border-collapse:collapse;font-size:16px}
.sheet th,.sheet td{border:1px solid var(--line);padding:8px 10px;text-align:left}
.sheet code,.sheet pre{font-family:ui-monospace,Menlo,Consolas,monospace;font-size:16px}
.sheet pre{overflow-x:auto;padding:12px;background:rgba(0,0,0,.28);border:1px solid var(--line)}

.sheet article{scroll-margin-top:112px}
.sheet article + article{
  margin-top:2.4rem;
  padding-top:2.4rem;
  border-top:1px solid rgba(255,255,255,.14);
}

/* 页脚 */
footer{
  position:relative;
  z-index:1;
  margin-top:48px;
  padding:34px 20px 28px;
  border-top:1px solid var(--line);
  background:rgba(255,255,255,.05);
  -webkit-backdrop-filter:blur(15px);
  backdrop-filter:blur(15px);
  box-shadow:inset 0 1px 0 rgba(255,255,255,.18);
}

.foot-grid{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:20px;
  max-width:1100px;
  margin:0 auto 24px;
}

.foot-col{
  margin:0;
  padding:14px 16px;
  background:rgba(255,255,255,.05);
  border:1px solid var(--line);
  box-shadow:0 24px 44px -34px #000;
}

.foot-col dt{
  margin-bottom:8px;
  font-size:16px;
  letter-spacing:.2em;
  color:#fff;
}

.foot-col dd{margin:0;font-size:16px;color:var(--muted)}

.foot-nav{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:2px}
.foot-nav a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  padding:0 8px;
  color:var(--muted);
  text-decoration:none;
  font-size:16px;
}
.foot-nav a:hover{color:#fff;background:rgba(255,255,255,.12)}

.sub{display:flex;flex-wrap:wrap;gap:8px}
.sub input{
  flex:1 1 120px;
  min-width:0;
  min-height:44px;
  padding:0 12px;
  font:inherit;
  font-size:16px;
  color:#fff;
  background:rgba(255,255,255,.09);
  border:1px solid var(--line);
}
.sub input::placeholder{color:#b39ba1}
.sub button{
  min-height:44px;
  padding:0 18px;
  font:inherit;
  font-size:16px;
  color:#fff;
  cursor:pointer;
  border:0;
  background:linear-gradient(135deg,var(--red),var(--violet));
  box-shadow:0 12px 26px -14px rgba(255,0,0,.9);
}
.sub button:hover{transform:translateY(-2px);box-shadow:0 16px 30px -12px rgba(139,0,255,.9)}

.copy{
  max-width:1100px;
  margin:0 auto;
  text-align:center;
  font-size:16px;
  letter-spacing:.1em;
  color:#bea7ac;
}

/* 动效 */
@media (prefers-reduced-motion:no-preference){
  .menu li,.anchors li,.side-list li{
    opacity:0;
    transform:translateY(8px);
    animation:kmt-rise .5s cubic-bezier(.2,.7,.3,1) forwards;
  }
  @keyframes kmt-rise{to{opacity:1;transform:none}}

  .js .sheet article{
    opacity:0;
    transform:translateY(16px);
    transition:opacity .55s ease,transform .55s ease;
  }
  .js .sheet article.seen{opacity:1;transform:none}
}

/* 移动端 */
@media (max-width:900px){
  .topbar{
    grid-template-columns:minmax(0,1fr);
    padding:8px 12px;
    gap:2px;
  }
  .brand{order:-1;justify-self:center;padding:8px 10px}
  .menu a{font-size:16px}
  .menu-a .tier,.menu-b .tier{justify-content:flex-start}
  .anchors ul{padding:5px 12px}

  .shell{
    grid-template-columns:minmax(0,1fr);
    gap:20px;
    padding:18px 14px 40px;
  }
  .side{position:static;order:-1}
  .side-h{margin:0 0 8px;font-size:16px}
  .side-list{
    display:flex;
    gap:6px;
    overflow-x:auto;
    padding:8px;
    scrollbar-width:none;
  }
  .side-list::-webkit-scrollbar{display:none}
  .side-list li{flex:0 0 auto}
  .side-list a{
    min-height:44px;
    border-left:0;
    border-bottom:2px solid transparent;
    white-space:nowrap;
  }
  .side-list a:hover{transform:none}

  .hero{
    min-height:0;
    padding:44px 18px;
    gap:14px;
  }
  .mark svg{width:34px;height:34px}
  .sheet{margin-top:20px;padding:22px 16px 32px}
  .sheet article{scroll-margin-top:132px}
  .foot-grid{grid-template-columns:minmax(0,1fr);gap:14px}
  footer{margin-top:32px;padding:24px 14px 22px}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .menu li,.anchors li,.side-list li{opacity:1;transform:none;animation:none}
  .js .sheet article{opacity:1;transform:none;transition:none}
}

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