:root{
  --navy-900:#0B1826;
  --navy-800:#122A40;
  --navy-700:#1B3A57;
  --frost:#7FA8C9;
  --paper:#F3EEE4;
  --paper-shadow:#C9BFAE;
  --amber:#F2A33C;
  --amber-deep:#D9821B;
  --cyan:#4BE0D0;
  --alert:#E4552B;
  --ink:#1A1614;
  --bright:#EDF3F8;

  --line-dark:rgba(127,168,201,.26);
  --line-soft:rgba(127,168,201,.14);
  --line-paper:rgba(26,22,20,.16);

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

  --radius-s:6px;
  --radius-m:12px;
  --radius-l:20px;
  --radius-pill:999px;

  --wrap:1180px;
  --dur:160ms;
  --ease:cubic-bezier(.2,.7,.3,1);
}

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

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

body{
  margin:0;
  min-height:100vh;
  overflow-x:hidden;
  background:
    radial-gradient(1200px 620px at 78% -12%,rgba(27,58,87,.62),transparent 70%),
    radial-gradient(900px 520px at 6% 0%,rgba(75,224,208,.06),transparent 65%),
    var(--navy-900);
  color:var(--bright);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.9;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
}

h1,h2,h3,h4{
  margin:0;
  font-family:var(--font-display);
  font-weight:800;
  font-stretch:88%;
  line-height:1.24;
  letter-spacing:-.015em;
  color:var(--bright);
}

p{margin:0}
p + p{margin-top:1.15em}

ul,ol{margin:0;padding:0;list-style:none}
img,svg{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0;padding:0;cursor:pointer}
a{color:inherit;text-decoration:none}
code,kbd,samp{font-family:var(--font-mono)}

::selection{background:var(--amber);color:var(--ink)}

:focus-visible{
  outline:2px solid var(--cyan);
  outline-offset:3px;
  border-radius:4px;
}

#main-content{display:block}

.mono{
  font-family:var(--font-mono);
  letter-spacing:.08em;
  font-variant-numeric:tabular-nums;
}

.sr-only{
  position:absolute;width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0;
}

/* ---------- 容器与页面骨架 ---------- */
.wrap{
  width:min(var(--wrap),100% - 32px);
  margin-inline:auto;
}

.page{padding-top:clamp(20px,3vw,40px);padding-bottom:clamp(40px,6vw,80px)}

.divider{height:1px;background:var(--line-soft);border:0;margin:0}

.breadcrumbs{padding:10px 0 0}

.crumb-list{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:.72rem;letter-spacing:.06em;
  color:var(--frost);
}

.crumb-item + .crumb-item::before{
  content:"/";margin-right:8px;color:rgba(127,168,201,.5);
}

.crumb-link{
  color:rgba(237,243,248,.8);
  border-bottom:1px solid transparent;
  transition:color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.crumb-link:hover{color:var(--bright);border-bottom-color:var(--amber)}

.crumb-current{color:var(--amber)}

.page-head{padding:clamp(18px,3vw,34px) 0 clamp(14px,2vw,24px)}

.page-title{
  font-size:clamp(1.72rem,4.4vw,2.55rem);
  font-stretch:86%;
  letter-spacing:-.02em;
}

.page-lede{
  margin-top:12px;
  max-width:62ch;
  font-size:1rem;
  line-height:1.95;
  color:rgba(237,243,248,.76);
}

/* ---------- 区块 ---------- */
.section{padding:clamp(26px,4vw,52px) 0}
.section + .section{border-top:1px solid var(--line-soft)}

.section-head{
  display:flex;align-items:baseline;flex-wrap:wrap;gap:10px 14px;
  margin-bottom:clamp(14px,2vw,22px);
}

.section-num{
  font-family:var(--font-mono);
  font-size:.74rem;
  letter-spacing:.16em;
  color:var(--amber);
  display:inline-flex;align-items:center;gap:9px;
}
.section-num::before{
  content:"";width:7px;height:7px;border-radius:50%;
  background:var(--amber);box-shadow:0 0 0 3px rgba(242,163,60,.16);
}

.section-title{font-size:clamp(1.24rem,2.6vw,1.72rem)}
.section-note{font-size:.82rem;color:var(--frost);max-width:56ch}

/* ---------- 卡片 ---------- */
.card-grid{
  display:grid;gap:clamp(12px,2vw,20px);
  grid-template-columns:repeat(auto-fit,minmax(240px,1fr));
}

.card{
  background:var(--navy-800);
  border:1px solid var(--line-dark);
  border-radius:var(--radius-m);
  padding:clamp(16px,2vw,22px);
  transition:border-color var(--dur) var(--ease),box-shadow var(--dur) var(--ease),transform var(--dur) var(--ease);
}
.card:hover{
  border-color:rgba(75,224,208,.4);
  box-shadow:0 14px 30px rgba(4,10,18,.5);
  transform:translateY(-2px);
}

.paper{
  background:var(--paper);
  color:var(--ink);
  border:1px solid var(--paper-shadow);
  border-radius:var(--radius-m);
  padding:clamp(18px,2.4vw,28px);
  box-shadow:0 2px 0 rgba(201,191,174,.9),0 16px 30px rgba(4,10,18,.38);
}
.paper h2,.paper h3,.paper h4{color:var(--ink)}
.paper p{color:rgba(26,22,20,.86)}
.paper .mono{color:var(--amber-deep)}

.index-card{
  position:relative;
  background:var(--paper);
  color:var(--ink);
  border:1px solid var(--paper-shadow);
  border-radius:var(--radius-m);
  padding:clamp(18px,2.4vw,26px);
  box-shadow:0 2px 0 rgba(201,191,174,.95),0 18px 32px rgba(4,10,18,.42);
  transition:transform 220ms var(--ease),box-shadow 220ms var(--ease);
}
.index-card::before{
  content:"";position:absolute;inset:5px;border:1px solid rgba(26,22,20,.1);
  border-radius:8px;pointer-events:none;
}
.index-card:hover{
  transform:translateY(-3px);
  box-shadow:0 3px 0 rgba(201,191,174,.95),0 24px 40px rgba(4,10,18,.5);
}
.index-card h3{color:var(--ink)}
.index-card p{color:rgba(26,22,20,.82)}

/* ---------- 标签与按钮 ---------- */
.tag{
  display:inline-flex;align-items:center;gap:6px;
  font-family:var(--font-mono);font-size:.68rem;letter-spacing:.1em;
  padding:3px 8px;border-radius:var(--radius-s);
  border:1px solid currentColor;color:var(--frost);
  white-space:nowrap;
}
.tag--amber{color:var(--amber)}
.tag--cyan{color:var(--cyan)}
.tag--alert{color:var(--alert)}
.tag--ink{color:rgba(26,22,20,.72)}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:12px 20px;border-radius:var(--radius-pill);
  font-family:var(--font-display);font-stretch:90%;
  font-size:.92rem;font-weight:700;
  border:1px solid transparent;
  transition:background var(--dur) var(--ease),color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.btn--primary{background:var(--amber);color:var(--navy-900)}
.btn--primary:hover{background:var(--amber-deep)}
.btn--ghost{border-color:var(--line-dark);color:var(--bright);background:rgba(27,58,87,.4)}
.btn--ghost:hover{border-color:var(--cyan);color:var(--cyan)}
.btn--paper{border-color:rgba(26,22,20,.35);color:var(--ink);background:transparent}
.btn--paper:hover{background:var(--ink);color:var(--paper)}

/* ---------- 状态点 ---------- */
.signal{
  display:inline-block;width:7px;height:7px;border-radius:50%;
  background:var(--amber);box-shadow:0 0 0 3px rgba(242,163,60,.14);
}
.signal--cyan{background:var(--cyan);box-shadow:0 0 0 3px rgba(75,224,208,.16)}

/* ---------- 图片容器（页面阶段放 <img>） ---------- */
.img-slot{
  position:relative;overflow:hidden;
  border-radius:var(--radius-m);
  background:
    linear-gradient(135deg,rgba(27,58,87,.9),rgba(11,24,38,.9));
  border:1px solid var(--line-dark);
  aspect-ratio:4/3;
}
.img-slot img{width:100%;height:100%;object-fit:cover;object-position:center}
.img-slot--paper{background:var(--paper);border-color:var(--paper-shadow)}
.img-slot--cut{
  clip-path:polygon(0 0,100% 4%,100% 100%,0 96%);
  border-radius:0;
}
.img-slot--16x9{aspect-ratio:16/9}
.img-slot--1x1{aspect-ratio:1/1}
.img-slot--3x4{aspect-ratio:3/4}
.img-slot-label{
  position:absolute;left:10px;bottom:10px;
  font-family:var(--font-mono);font-size:.66rem;letter-spacing:.1em;
  background:rgba(11,24,38,.84);color:var(--bright);
  padding:4px 8px;border-radius:var(--radius-s);
  border:1px solid var(--line-dark);
}

/* ---------- 头部 ---------- */
.site-header{
  position:sticky;top:0;z-index:60;
  padding:10px 0 0;
  pointer-events:none;
}

.scroll-meter{
  position:absolute;left:0;right:0;top:0;height:2px;
  background:rgba(127,168,201,.14);
  overflow:hidden;pointer-events:none;
}
.scroll-meter > span{
  display:block;height:100%;width:100%;
  transform-origin:0 50%;
  transform:scaleX(var(--scroll-progress,0));
  background:linear-gradient(90deg,var(--amber),var(--cyan));
  transition:transform 120ms linear;
}

.skip-link{
  position:fixed;top:10px;left:10px;z-index:200;
  padding:10px 16px;border-radius:var(--radius-s);
  background:var(--amber);color:var(--ink);
  font-weight:700;font-size:.9rem;
  transform:translateY(-180%);
  transition:transform var(--dur) var(--ease);
  pointer-events:auto;
}
.skip-link:focus{transform:translateY(0)}

.header-bar{
  pointer-events:auto;
  width:min(var(--wrap),100% - 32px);
  margin-inline:auto;
  display:flex;align-items:center;gap:8px;
  padding:8px 10px 8px 12px;
  background:rgba(18,42,64,.9);
  border:1px solid var(--line-dark);
  border-radius:var(--radius-pill);
  backdrop-filter:blur(14px) saturate(1.2);
  -webkit-backdrop-filter:blur(14px) saturate(1.2);
  box-shadow:0 12px 32px rgba(4,10,18,.48);
  transition:padding var(--dur) var(--ease),background var(--dur) var(--ease),border-radius var(--dur) var(--ease);
}
.site-header[data-scrolled] .header-bar{
  padding:6px 8px 6px 10px;
  background:rgba(13,32,50,.96);
}

.brand-island{display:flex;align-items:center;gap:8px;flex:0 0 auto}

.brand-link{
  display:flex;align-items:center;gap:9px;
  padding:6px 6px 6px 4px;border-radius:var(--radius-pill);
}
.brand-mark{
  width:12px;height:12px;border-radius:3px;background:var(--amber);
  transition:background var(--dur) var(--ease),box-shadow var(--dur) var(--ease);
  flex:0 0 auto;
}
.brand-link:hover .brand-mark,
.brand-link:focus-visible .brand-mark{
  background:var(--cyan);box-shadow:0 0 0 4px rgba(75,224,208,.18);
}
.brand-name{
  font-family:var(--font-display);font-weight:800;font-stretch:90%;
  font-size:1.02rem;letter-spacing:.02em;color:var(--bright);
  white-space:nowrap;
}

.version-chip{
  display:inline-flex;align-items:center;
  padding:4px 8px;border-radius:var(--radius-s);
  background:var(--amber);color:var(--navy-900);
  font-family:var(--font-mono);font-size:.72rem;line-height:1.3;
  transition:background var(--dur) var(--ease),color var(--dur) var(--ease);
}
.version-chip:hover{background:var(--amber-deep)}
.version-chip[data-copied]{
  background:var(--cyan);color:var(--navy-900);
}

.nav-toggle{
  display:none;align-items:center;gap:8px;
  margin-left:auto;
  padding:8px 14px;border-radius:var(--radius-pill);
  border:1px solid var(--line-dark);
  color:var(--bright);font-size:.85rem;font-weight:700;
  transition:border-color var(--dur) var(--ease);
}
.nav-toggle:hover{border-color:var(--cyan)}
.nav-toggle-icon{display:flex;flex-direction:column;gap:4px;width:14px}
.nav-toggle-bar{
  height:2px;border-radius:2px;background:var(--frost);
  transition:transform var(--dur) var(--ease),background var(--dur) var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar{background:var(--cyan)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:first-child{transform:translateY(3px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:last-child{transform:translateY(-3px) rotate(-45deg)}
.nav-toggle-text{white-space:nowrap}

.nav-island{
  display:flex;align-items:center;gap:6px;
  margin-left:auto;min-width:0;
}
.nav-list{display:flex;align-items:center;gap:2px}
.nav-link{
  display:block;padding:8px 12px;border-radius:var(--radius-pill);
  font-size:.92rem;font-weight:600;
  color:rgba(237,243,248,.72);
  white-space:nowrap;
  transition:color var(--dur) var(--ease),background var(--dur) var(--ease),box-shadow var(--dur) var(--ease);
}
.nav-link:hover{color:var(--bright);background:rgba(27,58,87,.72)}
.nav-link[aria-current="page"]{
  color:var(--bright);
  background:rgba(75,224,208,.14);
  box-shadow:inset 0 0 0 1px rgba(75,224,208,.48);
}

.nav-tools{
  display:flex;align-items:center;gap:6px;
  margin-left:6px;padding-left:8px;
  border-left:1px solid var(--line-soft);
}
.tool-link{
  padding:7px 10px;border-radius:var(--radius-pill);
  font-size:.86rem;font-weight:600;color:var(--frost);
  white-space:nowrap;
  transition:color var(--dur) var(--ease),background var(--dur) var(--ease);
}
.tool-link:hover{color:var(--bright);background:rgba(27,58,87,.72)}
.tool-copy{
  padding:7px 14px;border-radius:var(--radius-pill);
  background:var(--amber);color:var(--navy-900);
  font-size:.82rem;font-weight:700;white-space:nowrap;
  transition:background var(--dur) var(--ease),color var(--dur) var(--ease);
}
.tool-copy:hover{background:var(--amber-deep)}
.tool-copy[data-copied]{background:var(--cyan);color:var(--navy-900)}

.header-note{
  width:min(var(--wrap),100% - 32px);
  margin:6px auto 0;
  text-align:right;
  font-family:var(--font-mono);
  font-size:.68rem;letter-spacing:.08em;
  color:rgba(127,168,201,.7);
  pointer-events:none;
}

/* ---------- 页脚 ---------- */
.site-footer{
  position:relative;
  margin-top:clamp(48px,8vw,96px);
  background:var(--navy-800);
  border-top:1px solid var(--line-dark);
  color:var(--bright);
}
.site-footer::before{
  content:"";position:absolute;left:0;right:0;top:0;height:3px;
  background:linear-gradient(90deg,var(--amber),rgba(242,163,60,0) 42%,rgba(75,224,208,.9));
  opacity:.65;
}

.footer-inner{
  width:min(var(--wrap),100% - 32px);
  margin-inline:auto;
  display:grid;
  grid-template-columns:minmax(0,1.1fr) minmax(0,2fr);
  gap:clamp(24px,4vw,56px);
  padding:clamp(32px,5vw,64px) 0 clamp(24px,3vw,40px);
}

.footer-brand{display:flex;flex-direction:column;gap:8px}
.footer-mark{
  width:28px;height:28px;border-radius:8px;
  background:linear-gradient(135deg,var(--amber),var(--alert));
}
.footer-name{
  font-family:var(--font-display);font-weight:800;font-stretch:88%;
  font-size:1.2rem;letter-spacing:.02em;
}
.footer-version{font-size:.78rem;color:var(--frost)}
.footer-version .mono{color:var(--amber)}
.footer-domain{
  font-family:var(--font-mono);font-size:.74rem;letter-spacing:.08em;
  color:rgba(127,168,201,.72);
}

.footer-columns{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:clamp(16px,3vw,32px);
}
.footer-col-title{
  font-family:var(--font-mono);font-weight:500;
  font-size:.72rem;letter-spacing:.16em;
  color:var(--frost);
  padding-bottom:10px;margin-bottom:12px;
  border-bottom:1px solid var(--line-soft);
}
.footer-list{display:flex;flex-direction:column;gap:6px}
.footer-link{
  display:inline-block;
  font-size:.9rem;color:rgba(237,243,248,.78);
  padding:2px 0;border-bottom:1px solid transparent;
  transition:color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.footer-link:hover{color:var(--bright);border-bottom-color:var(--amber)}

.footer-meta{
  border-top:1px solid var(--line-soft);
  background:rgba(11,24,38,.62);
}
.footer-meta-inner{
  width:min(var(--wrap),100% - 32px);
  margin-inline:auto;
  padding:18px 0 28px;
  display:flex;flex-wrap:wrap;align-items:baseline;
  gap:8px 24px;justify-content:space-between;
}
.footer-contact{
  font-size:.82rem;line-height:1.85;
  color:rgba(237,243,248,.72);
  max-width:64ch;
}
.footer-legal,.footer-copy{
  font-family:var(--font-mono);
  font-size:.72rem;letter-spacing:.06em;
  color:var(--frost);
}

/* ---------- 返回顶部 ---------- */
.back-to-top{
  position:fixed;right:16px;bottom:16px;z-index:70;
  width:46px;height:46px;border-radius:var(--radius-pill);
  display:grid;place-items:center;
  background:rgba(18,42,64,.94);
  color:var(--bright);
  border:1px solid var(--line-dark);
  font-family:var(--font-mono);font-size:1rem;line-height:1;
  box-shadow:0 12px 26px rgba(4,10,18,.55);
  opacity:0;visibility:hidden;transform:translateY(8px);
  transition:opacity 220ms var(--ease),transform 220ms var(--ease),visibility 220ms,color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.back-to-top[data-visible]{opacity:1;visibility:visible;transform:translateY(0)}
.back-to-top:hover{border-color:var(--cyan);color:var(--cyan)}

/* ---------- 目录跟随 ---------- */
[data-toc] a[aria-current]{color:var(--amber)}

/* ---------- 响应式 ---------- */
@media (max-width:1100px){
  .nav-link{padding:8px 9px;font-size:.88rem}
  .tool-link{display:none}
}

@media (max-width:899px){
  .site-header{padding-top:8px}

  .header-bar{
    flex-wrap:wrap;
    border-radius:var(--radius-l);
    padding:8px 10px;
  }
  .site-header[data-scrolled] .header-bar{padding:8px 10px}

  .nav-toggle{display:inline-flex}

  .nav-island{
    display:none;
    width:100%;
    margin:8px 0 0;
    padding-top:8px;
    flex-direction:column;
    align-items:stretch;
    gap:0;
    border-top:1px solid var(--line-soft);
  }
  .nav-island[data-open]{display:flex}

  .nav-list{flex-direction:column;align-items:stretch;gap:2px}
  .nav-link{padding:11px 12px;border-radius:var(--radius-m);font-size:.95rem}

  .nav-tools{
    margin:8px 0 0;padding:8px 0 0;
    border-left:0;border-top:1px solid var(--line-soft);
    flex-direction:column;align-items:stretch;gap:8px;
  }
  .tool-link{display:block;text-align:center;padding:11px;border-radius:var(--radius-m)}
  .tool-copy{text-align:center;padding:12px;border-radius:var(--radius-m)}

  .header-note{display:none}

  .footer-inner{grid-template-columns:1fr}
}

@media (max-width:560px){
  .footer-columns{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-meta-inner{flex-direction:column;align-items:flex-start;gap:10px}
  .version-chip{padding:3px 7px;font-size:.68rem}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  .card:hover,
  .index-card:hover{transform:none}
  .scroll-meter > span{transition:none}
}