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

:root{
  --ink:#12122B;
  --ink2:#191934;
  --ink3:#23234B;
  --amber:#F2A93B;
  --paper:#F7F7FA;
  --mute:rgba(247,247,250,.66);
  --line:rgba(247,247,250,.14);
  --r:10px;
  --sh:0 16px 36px rgba(4,4,16,.45);
}

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

html{scroll-behavior:smooth;overflow-x:hidden;background:var(--ink)}

body{
  margin:0;
  overflow-x:hidden;
  background:var(--ink);
  color:var(--paper);
  font:400 17px/1.72 Inter,"Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  letter-spacing:.004em;
  -webkit-text-size-adjust:100%;
}

body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:0;
  pointer-events:none;
  background-image:radial-gradient(rgba(247,247,250,.11) 1px,transparent 1px);
  background-size:26px 26px;
  opacity:.5;
  -webkit-mask-image:linear-gradient(180deg,rgba(0,0,0,.95),rgba(0,0,0,.18));
  mask-image:linear-gradient(180deg,rgba(0,0,0,.95),rgba(0,0,0,.18));
}

a{color:inherit}
img{display:block;max-width:100%;height:auto}
button{font:inherit}

.wrap{width:min(1180px,100% - 32px);margin-inline:auto;max-width:100%}

.mast,.railbar,main,.foot{position:relative;z-index:1}

/* ---------- 顶部 ---------- */
.mast{
  border-bottom:1px solid var(--line);
  background:linear-gradient(180deg,rgba(18,18,43,.94),rgba(18,18,43,.6));
}

.mast-row{
  display:grid;
  grid-template-columns:minmax(0,1fr) auto minmax(0,1fr);
  align-items:center;
  gap:10px;
  padding-block:10px;
}
.mast-row>*{min-width:0}

.nav{min-width:0;max-width:100%}

.nav ol{
  display:flex;
  gap:2px;
  margin:0;
  padding:0;
  list-style:none;
  overflow-x:auto;
  overscroll-behavior-x:contain;
  scrollbar-width:none;
}
.nav ol::-webkit-scrollbar{display:none}
.nav-a ol{justify-content:flex-end}
.nav-b ol{justify-content:flex-start}

.nav a{
  position:relative;
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:6px 11px;
  font-size:16px;
  color:var(--paper);
  text-decoration:none;
  white-space:nowrap;
  border-radius:8px;
}
.nav a::after{
  content:"";
  position:absolute;
  left:11px;
  right:11px;
  bottom:8px;
  height:2px;
  background:var(--amber);
  transform:scaleX(0);
  transform-origin:left;
  transition:transform .25s ease;
}
.nav a:hover,.nav a:focus-visible{color:var(--amber)}
.nav a:hover::after,.nav a:focus-visible::after{transform:scaleX(1)}

.brand{
  display:inline-flex;
  align-items:center;
  gap:8px;
  min-height:44px;
  padding:7px 15px;
  border:1px solid var(--line);
  border-radius:999px;
  color:var(--paper);
  font-weight:600;
  letter-spacing:.05em;
  text-decoration:none;
  white-space:nowrap;
}
.brand .mark{height:22px;width:auto}
.brand:hover,.brand:focus-visible{border-color:var(--amber);color:var(--amber)}

.sub{
  position:absolute;
  top:calc(100% + 4px);
  left:0;
  z-index:30;
  min-width:186px;
  margin:0;
  padding:6px;
  list-style:none;
  display:grid;
  gap:2px;
  background:var(--ink2);
  border:1px solid var(--line);
  border-radius:var(--r);
  box-shadow:var(--sh);
  opacity:0;
  visibility:hidden;
  transform:translateY(-5px);
  transition:opacity .18s ease,transform .18s ease,visibility .18s;
}
.sub a{width:100%}
li:has(> .sub){position:relative}
li.has-sub{position:relative}
li:has(> .sub):hover .sub,
li:has(> .sub):focus-within .sub,
li.has-sub:hover .sub,
li.has-sub:focus-within .sub{opacity:1;visibility:visible;transform:none}

/* ---------- 粘性锚点条 ---------- */
.railbar{
  position:sticky;
  top:0;
  z-index:20;
  background:rgba(18,18,43,.9);
  -webkit-backdrop-filter:blur(8px);
  backdrop-filter:blur(8px);
  border-bottom:1px solid var(--line);
}
.rail{padding-block:5px}
.rail ol{
  display:flex;
  gap:4px;
  margin:0;
  padding:0;
  list-style:none;
  overflow-x:auto;
  overscroll-behavior-x:contain;
  scrollbar-width:none;
}
.rail ol::-webkit-scrollbar{display:none}
.rail a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  padding:6px 13px;
  font-size:16px;
  color:var(--mute);
  text-decoration:none;
  white-space:nowrap;
  border:1px solid var(--line);
  border-radius:999px;
  transition:color .2s ease,background .2s ease,border-color .2s ease;
}
.rail a:hover,.rail a:focus-visible,.rail a[aria-current]{
  color:var(--ink);
  background:var(--amber);
  border-color:var(--amber);
}

/* ---------- 主区 ---------- */
main{padding-block:22px 60px}

.stage{
  position:relative;
  display:flex;
  flex-direction:column;
  justify-content:flex-end;
  min-height:45vh;
  padding:26px 0 18px;
  overflow:hidden;
}

.stage-art{
  position:absolute;
  inset:0;
  margin:0;
  z-index:0;
  display:flex;
  align-items:center;
  justify-content:flex-start;
  pointer-events:none;
}

.dots{
  display:block;
  width:46%;
  height:76%;
  background-image:radial-gradient(var(--amber) 1.6px,transparent 1.6px);
  background-size:16px 16px;
  opacity:.5;
  animation:drift 24s linear infinite;
}

@keyframes drift{
  to{background-position:160px 160px}
}

.stage-copy{position:relative;z-index:2;text-align:right}

.mega{
  margin:0;
  overflow-wrap:break-word;
  font-size:clamp(2.2rem,7vw,4.9rem);
  line-height:1.04;
  font-weight:600;
  letter-spacing:-.02em;
  background:linear-gradient(100deg,var(--paper) 18%,var(--amber) 48%,var(--paper) 78%);
  background-size:220% 100%;
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
  -webkit-text-fill-color:transparent;
  animation:sweep 10s linear infinite;
}

@keyframes sweep{
  to{background-position:-220% 0}
}

.stage-sub{
  margin:14px 0 0 auto;
  max-width:54ch;
  font-size:17px;
  line-height:1.7;
  color:var(--mute);
  text-align:right;
  overflow-wrap:break-word;
}

.body{
  display:grid;
  grid-template-columns:248px minmax(0,1fr);
  gap:42px;
  align-items:start;
  margin-top:44px;
}

/* ---------- 目录侧栏 ---------- */
.side{
  position:sticky;
  top:74px;
  min-width:0;
  padding:18px 16px;
  border:1px solid var(--line);
  border-radius:var(--r);
  background:linear-gradient(180deg,rgba(242,169,59,.1),rgba(242,169,59,0) 62%);
  box-shadow:var(--sh);
}

.side-h{
  margin:0 0 10px;
  font-size:17px;
  font-weight:600;
  letter-spacing:.06em;
}

.side-list{
  display:grid;
  gap:2px;
  margin:0;
  padding:0;
  list-style:none;
}
.side-list a{
  display:flex;
  align-items:center;
  min-height:40px;
  padding:7px 8px;
  font-size:16px;
  border-left:2px solid transparent;
  border-radius:0 8px 8px 0;
  text-decoration:none;
  color:var(--paper);
  transition:background .2s ease,border-color .2s ease,color .2s ease;
}
.side-list a:hover,.side-list a:focus-visible{
  background:rgba(242,169,59,.16);
  border-left-color:var(--amber);
  color:var(--amber);
}

/* ---------- 正文 ---------- */
small{
  display:block;
  margin:0 0 6px;
  font-size:15px;
  font-weight:500;
  line-height:1.5;
  letter-spacing:.2em;
  color:var(--amber);
}
small+h2{margin-top:0}

.prose{min-width:0;max-width:100%;counter-reset:sec;overflow-wrap:break-word}
.prose>section[id]{
  counter-increment:sec;
  margin-top:46px;
  padding-top:38px;
  border-top:1px solid var(--line);
  scroll-margin-top:76px;
}
.prose>section[id]:first-child{
  margin-top:0;
  padding-top:0;
  border-top:0;
}
.prose>section[id]::before{
  content:counter(sec,decimal-leading-zero);
  display:block;
  margin-bottom:8px;
  font-size:14px;
  letter-spacing:.24em;
  color:var(--amber);
  font-variant-numeric:tabular-nums;
}

.prose h2{
  margin:0 0 14px;
  font-size:clamp(1.42rem,3vw,2.05rem);
  line-height:1.28;
  font-weight:600;
  letter-spacing:-.012em;
}
.prose h3{
  margin:26px 0 10px;
  font-size:1.18rem;
  font-weight:600;
  color:var(--amber);
}
.prose h4{margin:22px 0 8px;font-size:1.05rem;font-weight:600}
.prose p{margin:0 0 16px}
.prose ul,.prose ol{margin:0 0 18px;padding-left:1.3em}
.prose li{margin:0 0 8px}
.prose li::marker{color:var(--amber)}
.prose a{color:var(--amber);text-underline-offset:3px;overflow-wrap:break-word}
.prose figure{margin:24px 0;border-radius:var(--r);overflow:hidden;box-shadow:var(--sh)}
.prose img{width:100%;border-radius:var(--r)}
.prose blockquote{
  margin:24px 0;
  padding:14px 20px;
  background:var(--ink2);
  border-left:3px solid var(--amber);
  border-radius:0 var(--r) var(--r) 0;
}
.prose blockquote p:last-child{margin:0}
.prose table{display:block;width:100%;max-width:100%;overflow-x:auto;border-collapse:collapse;margin:0 0 20px;font-size:16px}
.prose th,.prose td{padding:9px 10px;text-align:left;border-bottom:1px solid var(--line)}
.prose th{color:var(--amber);font-weight:600}
.prose pre{max-width:100%;overflow-x:auto}
.prose hr{margin:28px 0;border:0;border-top:1px solid var(--line)}
.prose code{padding:1px 5px;font-size:15px;background:var(--ink3);border-radius:5px}
.prose time{
  display:inline-block;
  font-size:15px;
  color:var(--mute);
  font-variant-numeric:tabular-nums;
}

/* ---------- 页脚 ---------- */
.foot{
  display:grid;
  grid-template-columns:minmax(0,1.5fr) minmax(0,1fr) minmax(0,1fr);
  gap:32px;
  margin-top:56px;
  padding:42px 24px 26px;
  border-top:1px solid var(--line);
  background:var(--ink2);
}
.foot dl{margin:0;min-width:0}
.foot dt{
  margin:0 0 8px;
  font-size:15px;
  font-weight:500;
  letter-spacing:.18em;
  color:var(--amber);
}
.foot dd{margin:0;color:var(--mute);font-size:16px;overflow-wrap:break-word}
.foot ol{display:grid;gap:2px;margin:0;padding:0;list-style:none}
.foot a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  color:var(--paper);
  text-decoration:none;
}
.foot a:hover,.foot a:focus-visible{color:var(--amber)}
.copy{
  grid-column:1 / -1;
  margin:6px 0 0;
  padding-top:16px;
  border-top:1px solid var(--line);
  font-size:15px;
  color:var(--mute);
}

/* ---------- 动效 ---------- */
.rv{
  opacity:0;
  transform:translateY(16px);
  transition:opacity .55s ease,transform .55s cubic-bezier(.2,.72,.2,1);
}
.rv.in{opacity:1;transform:none}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .rv{opacity:1;transform:none;transition:none}
  .mega,.dots{animation:none}
  .nav a::after{transition:none}
}

/* ---------- 窄屏 ---------- */
@media (max-width:860px){
  .mast-row{
    grid-template-columns:minmax(0,1fr);
    justify-items:stretch;
    gap:4px;
    padding-block:8px;
  }
  .nav{width:auto;min-width:0;max-width:100%}
  .nav-a ol,.nav-b ol{justify-content:flex-start}
  .nav ol{padding-inline:1px}
  .brand{order:-1;justify-self:center;margin-bottom:2px}
  .nav-b ol{align-items:flex-start;flex-wrap:wrap;overflow-x:visible}
  .sub{
    position:static;
    display:flex;
    flex-wrap:wrap;
    gap:2px;
    padding:0;
    opacity:1;
    visibility:visible;
    transform:none;
    background:none;
    border:0;
    box-shadow:none;
    min-width:0;
  }
  .stage{min-height:42vh;padding-top:18px}
  .stage-art{width:64%}
  .dots{width:100%;height:100%}
  .mega{font-size:clamp(1.95rem,8.4vw,3rem)}
  .stage-sub{font-size:16px;margin-inline:0 0;max-width:100%}
  .body{grid-template-columns:minmax(0,1fr);gap:22px;margin-top:28px}
  .side{position:static}
  .side-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:2px}
  .foot{grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:18px;padding:30px 16px 22px;margin-top:38px}
  .foot dl:first-child{grid-column:1 / -1}
  main{padding-block:16px 40px}
}

@media (max-width:420px){
  .wrap{width:min(1180px,100% - 24px)}
  .mega{font-size:clamp(1.75rem,8.8vw,2.5rem)}
  .side-list{grid-template-columns:minmax(0,1fr)}
  .prose h2{font-size:clamp(1.3rem,6vw,1.7rem)}
}

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