:root{
  --blue:#3bb1ff;
  --red:#ff5252;
  --ink:#000;
  --paper:#fff;
  --base:#f6f3ea;
  --line:3px solid #000;
  --shadow:5px 5px 0 #000;
  --shadow-sm:4px 4px 0 #000;
  --maxw:1140px;
}

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

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

body{
  margin:0;
  background:var(--base);
  color:var(--ink);
  font-family:'Open Sans','PingFang SC','Hiragino Sans GB','Microsoft YaHei',system-ui,sans-serif;
  font-size:17px;
  line-height:1.7;
  overflow-x:hidden;
}

h1,h2,h3,h4,.brand-word,.nav-pills a,.rail-top,.hero-num,.ticker p{
  font-family:'Poppins','Open Sans','PingFang SC','Microsoft YaHei',system-ui,sans-serif;
  font-weight:700;
  letter-spacing:.01em;
}

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

/* ---------- 顶部细条 ---------- */
.ticker{
  background:var(--ink);
  color:#fff;
  border-bottom:var(--line);
  overflow:hidden;
}
.ticker p{
  margin:0;
  padding:6px 16px;
  font-size:13px;
  letter-spacing:.24em;
  text-transform:uppercase;
  text-align:center;
  white-space:nowrap;
  text-overflow:ellipsis;
  overflow:hidden;
}

/* ---------- 头部 ---------- */
.bar{
  position:sticky;
  top:0;
  z-index:40;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:14px;
  padding:12px 18px;
  background:var(--paper);
  border-bottom:var(--line);
}

.brand{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:6px 14px;
  background:var(--blue);
  border:var(--line);
  border-radius:4px;
  box-shadow:var(--shadow-sm);
  text-decoration:none;
  transform:rotate(-1.5deg);
}
.brand:hover,.brand:focus-visible{
  transform:rotate(-1.5deg) translate(-2px,-2px);
  box-shadow:6px 6px 0 #000;
}
.brand-word{
  font-size:20px;
  line-height:1.1;
}
.brand-logo{height:32px;width:auto;border-radius:2px}

/* ---------- 折叠导航 ---------- */
.nav-shell{position:relative}
.nav-shell > summary{
  list-style:none;
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:44px;
  min-width:84px;
  padding:8px 18px;
  background:var(--red);
  border:var(--line);
  border-radius:999px;
  box-shadow:var(--shadow-sm);
  font-weight:700;
  cursor:pointer;
  user-select:none;
}
.nav-shell > summary::-webkit-details-marker{display:none}
.nav-shell[open] > summary{background:var(--blue)}

.nav-pills{
  list-style:none;
  margin:10px 0 0;
  padding:10px;
  display:flex;
  flex-direction:column;
  gap:8px;
  position:absolute;
  right:0;
  top:100%;
  min-width:216px;
  background:var(--paper);
  border:var(--line);
  border-radius:4px;
  box-shadow:var(--shadow);
  z-index:50;
}
.nav-shell:not([open]) > .nav-pills{display:none}
.nav-pills a{
  display:flex;
  align-items:center;
  min-height:44px;
  padding:8px 14px;
  border:var(--line);
  border-radius:999px;
  background:var(--paper);
  text-decoration:none;
  font-size:16px;
}
.nav-pills a:hover,
.nav-pills a:focus-visible{
  background:var(--blue);
  box-shadow:var(--shadow-sm);
  transform:translate(-2px,-2px);
}

/* ---------- Hero ---------- */
.hero{
  position:relative;
  min-height:45vh;
  display:flex;
  align-items:flex-end;
  justify-content:flex-end;
  padding:26px 20px 44px;
  background:var(--blue);
  border-bottom:var(--line);
  overflow:hidden;
  clip-path:polygon(0 0,100% 0,100% 86%,0 100%);
}
.hero-media{
  position:absolute;
  inset:0;
  z-index:1;
}
.hero-media img,
.hero-img{
  width:100%;
  height:100%;
  object-fit:cover;
}
.hero-num{
  position:absolute;
  left:-.04em;
  bottom:-.16em;
  z-index:2;
  font-size:clamp(112px,25vw,250px);
  line-height:.82;
  color:#fff;
  -webkit-text-stroke:4px #000;
  paint-order:stroke fill;
  pointer-events:none;
  will-change:transform;
}
.hero-inner{
  position:relative;
  z-index:3;
  max-width:min(100%,720px);
  text-align:right;
}
.hero h1{
  margin:0;
  display:inline-block;
  font-size:clamp(26px,5.2vw,50px);
  line-height:1.2;
  padding:12px 18px;
  background:var(--paper);
  border:var(--line);
  border-radius:4px;
  box-shadow:var(--shadow);
  transform:rotate(-1deg);
}

/* ---------- 主体 ---------- */
.stage{
  max-width:var(--maxw);
  margin:0 auto;
  padding:30px 20px 64px;
  display:grid;
  grid-template-columns:minmax(0,1fr) 304px;
  gap:30px;
  align-items:start;
}

.paper{
  background:var(--paper);
  border:var(--line);
  border-radius:4px;
  box-shadow:var(--shadow);
  overflow:hidden;
}
.paper-inner > article{
  padding:26px 22px;
  scroll-margin-top:118px;
}
.paper-inner > article + article{border-top:var(--line)}
.paper-inner > article:first-child{padding-top:30px}

/* 正文排版 */
.paper-inner h2{
  margin:0 0 12px;
  font-size:clamp(21px,3vw,29px);
  line-height:1.28;
  scroll-margin-top:118px;
}
.paper-inner h3{
  margin:22px 0 10px;
  font-size:clamp(18px,2.3vw,21px);
  line-height:1.3;
}
.paper-inner h2 > span,
.paper-inner h3 > span{
  box-shadow:inset 0 -0.3em 0 var(--blue);
  padding-bottom:.06em;
}
.paper-inner p{margin:0 0 14px}
.paper-inner p:last-child{margin-bottom:0}
.paper-inner ul,.paper-inner ol{margin:0 0 16px;padding-left:1.3em}
.paper-inner li{margin:0 0 8px}
.paper-inner li::marker{color:var(--red);font-weight:700}
.paper-inner strong{font-weight:700;box-shadow:inset 0 -0.28em 0 rgba(255,82,82,.45)}
.paper-inner a{
  text-decoration:none;
  font-weight:700;
  border-bottom:3px solid var(--blue);
}
.paper-inner a:hover{border-bottom-color:var(--red)}
.paper-inner blockquote{
  margin:0 0 16px;
  padding:14px 18px;
  background:var(--base);
  border:var(--line);
  border-radius:4px;
  box-shadow:var(--shadow-sm);
}
.paper-inner blockquote p:last-child{margin-bottom:0}
.paper-inner img{
  border:var(--line);
  border-radius:4px;
  box-shadow:var(--shadow-sm);
  margin:0 0 16px;
}
.paper-inner table{
  width:100%;
  border-collapse:collapse;
  margin:0 0 18px;
  font-size:16px;
}
.paper-inner th,.paper-inner td{
  border:var(--line);
  padding:9px 12px;
  text-align:left;
}
.paper-inner th{background:var(--blue);font-weight:700}
.paper-inner code{
  font-family:ui-monospace,SFMono-Regular,Menlo,monospace;
  font-size:.94em;
  background:var(--base);
  border:2px solid #000;
  border-radius:3px;
  padding:1px 5px;
}

/* ---------- 侧栏 ---------- */
.rail{
  display:flex;
  flex-direction:column;
  gap:20px;
  position:sticky;
  top:104px;
}
.rail-block{
  border-radius:4px;
  padding:16px;
  box-shadow:var(--shadow);
}
.rail-block--blue{background:var(--blue)}
.rail-block--red{background:var(--red);color:#fff}
.rail-block h2,.rail-block h3{
  margin:0 0 12px;
  font-size:17px;
  line-height:1.2;
}
.rail-block h2 > span,
.rail-block h3 > span{
  display:inline-block;
  padding:3px 10px;
  background:#fff;
  color:#000;
  border:var(--line);
  border-radius:999px;
  box-shadow:var(--shadow-sm);
}
.rail-list{
  list-style:none;
  margin:0;
  padding:0;
  display:flex;
  flex-direction:column;
  gap:8px;
}
.rail-list a{
  display:flex;
  align-items:center;
  min-height:44px;
  padding:8px 12px;
  background:#fff;
  border:var(--line);
  border-radius:4px;
  text-decoration:none;
  font-weight:700;
  font-size:15px;
}
.rail-list a:hover,
.rail-list a:focus-visible{
  background:var(--ink);
  color:#fff;
  box-shadow:var(--shadow-sm);
  transform:translate(-2px,-2px);
}
.rail-top{
  display:flex;
  align-items:center;
  justify-content:center;
  min-height:44px;
  padding:8px 12px;
  background:var(--ink);
  color:#fff;
  border:var(--line);
  border-radius:4px;
  text-decoration:none;
  font-size:15px;
}
.rail-top:hover,.rail-top:focus-visible{background:#fff;color:#000}

/* ---------- 页脚 ---------- */
.foot{
  border-top:var(--line);
  background:var(--ink);
  color:#fff;
  display:grid;
  grid-template-columns:1fr auto 1fr;
  align-items:center;
  gap:12px;
  padding:22px 20px;
}
.foot p{margin:0}
.foot-brand{font-weight:700;font-size:18px}
.foot small{font-size:14px;opacity:.85;text-align:center;white-space:nowrap}
.foot-top{text-align:right}
.foot-top a{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:6px 16px;
  color:#fff;
  text-decoration:none;
  border:3px solid #fff;
  border-radius:999px;
  font-weight:700;
  font-size:15px;
}
.foot-top a:hover,.foot-top a:focus-visible{background:var(--blue);color:#000;border-color:#000}

/* ---------- 揭示动画 ---------- */
.reveal{
  opacity:0;
  transform:translateY(18px);
  transition:opacity .5s ease,transform .5s ease;
}
.reveal.is-in{opacity:1;transform:none}

:focus-visible{outline:3px solid var(--red);outline-offset:3px}

/* ---------- 断点 ---------- */
@media (min-width:980px){
  .nav-shell > summary{display:none}
  .nav-shell > .nav-pills,
  .nav-shell:not([open]) > .nav-pills{
    display:flex;
    flex-direction:row;
    flex-wrap:wrap;
    justify-content:flex-end;
    position:static;
    margin:0;
    padding:0;
    min-width:0;
    background:transparent;
    border:0;
    border-radius:0;
    box-shadow:none;
  }
  .nav-pills a{padding:8px 16px;font-size:15px}
}

@media (max-width:960px){
  .stage{grid-template-columns:minmax(0,1fr)}
  .rail{position:static;flex-direction:row;flex-wrap:wrap}
  .rail-block{flex:1 1 240px}
}

@media (max-width:640px){
  body{font-size:16px}
  .bar{padding:10px 14px}
  .brand-word{font-size:18px}
  .hero{min-height:45vh;padding:20px 16px 34px}
  .paper-inner > article{padding:20px 16px}
  .rail{flex-direction:column;gap:16px}
  .stage{padding:20px 14px 44px;gap:20px}
  .foot{
    grid-template-columns:1fr;
    justify-items:center;
    text-align:center;
    padding:18px 14px 26px;
  }
  .foot-top{text-align:center}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal{opacity:1;transform:none;transition:none}
  .hero-num{transform:none!important}
}

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