:root{
  --ink-900:#071A2B;
  --ink-800:#0E2740;
  --ink-700:#163A5A;
  --paper:#F4EFE6;
  --paper-bright:#FFF8EC;
  --orange:#FF6B2C;
  --lime:#B7FF3C;
  --mist:#8FA6B8;
  --amber:#FFB020;
  --peach:#FFB38A;
  --teal:#5FE3C0;
  --rail-w:208px;
  --topbar-h:64px;
  --gutter:clamp(20px,4vw,56px);
  --content-max:1180px;
  --radius-lg:28px;
  --radius-md:18px;
  --radius-pill:999px;
  --font-display:"Oswald","Noto Sans SC Condensed","HarmonyOS Sans SC","PingFang SC","Hiragino Sans GB",system-ui,sans-serif;
  --font-body:"Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"IBM Plex Mono","Roboto Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --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;
  padding-top:var(--topbar-h);
  font-family:var(--font-body);
  font-size:clamp(16px,1.02vw,17px);
  font-weight:400;
  line-height:1.8;
  color:#DCE7F0;
  background-color:var(--ink-900);
  background-image:
    radial-gradient(110% 70% at 100% -10%,rgba(22,58,90,.65),transparent 62%),
    radial-gradient(80% 55% at -10% 100%,rgba(255,107,44,.10),transparent 60%);
  background-repeat:no-repeat;
  min-height:100vh;
  -webkit-font-smoothing:antialiased;
}
img,svg,video{max-width:100%;display:block}
ul,ol{margin:0;padding:0;list-style:none}
h1,h2,h3,h4,p,figure{margin:0}
a{color:inherit}
button{font:inherit;color:inherit;background:none;border:0}
main{display:block}
#main-content{scroll-margin-top:calc(var(--topbar-h) + 12px)}
:focus-visible{outline:2px solid var(--lime);outline-offset:3px;border-radius:6px}

h1,h2,h3,h4{
  font-family:var(--font-display);
  font-weight:700;
  line-height:1.06;
  letter-spacing:-.02em;
  color:var(--paper-bright);
}
h1{font-size:clamp(3rem,8vw,7.5rem);line-height:.92;font-weight:800;letter-spacing:-.02em}
h2{font-size:clamp(1.9rem,3.6vw,3.2rem);line-height:1}
h3{font-size:clamp(1.15rem,1.6vw,1.5rem);line-height:1.2}
h4{font-size:1.05rem;line-height:1.3}

/* ============ 通用布局 ============ */
.u-wrap{width:100%;max-width:var(--content-max);margin-inline:auto;padding-inline:var(--gutter)}
.u-num{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:.02em}
.prose{max-width:68ch;font-size:1rem;line-height:1.85;color:#D3E0EB}
.prose p+p{margin-top:1em}
.prose h2,.prose h3{margin-top:1.6em;margin-bottom:.6em}
.grid{display:grid;gap:clamp(18px,2.4vw,28px)}
.grid--2{grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.grid--3{grid-template-columns:repeat(auto-fit,minmax(238px,1fr))}
.rule{height:1px;border:0;margin:0;background:linear-gradient(90deg,var(--orange),rgba(143,166,184,.28) 42%,transparent)}
.paper{
  background:var(--paper);
  color:#152A3C;
  border-radius:var(--radius-lg);
  padding:clamp(24px,4vw,56px);
  box-shadow:0 26px 60px rgba(3,12,20,.35);
}
.paper h2,.paper h3{color:var(--ink-800)}
.paper a{color:#B4431A;text-decoration:none;border-bottom:1px solid rgba(180,67,26,.4)}

/* ============ 头部轨道 ============ */
.site-header{z-index:90}
.rail{
  position:fixed;
  top:0;left:0;right:0;
  display:flex;
  flex-direction:column;
  height:var(--topbar-h);
  background:linear-gradient(180deg,#0C2438,#071A2B);
  border-bottom:1px solid var(--ink-700);
  box-shadow:0 10px 30px rgba(2,10,18,.45);
}
.skip-link{
  position:fixed;
  top:12px;left:12px;
  z-index:200;
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:0 18px;
  border-radius:var(--radius-pill);
  background:var(--lime);
  color:#08200A;
  font-size:14px;
  font-weight:700;
  text-decoration:none;
  transform:translateY(-180%);
  transition:transform .22s var(--ease);
}
.skip-link:focus{transform:translateY(0)}

.rail__top{
  position:relative;
  z-index:96;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  flex:1 1 auto;
  width:100%;
  padding:0 16px;
}
.rail__brand{
  display:flex;
  align-items:center;
  gap:10px;
  text-decoration:none;
  color:var(--paper-bright);
}
.rail__mark{
  display:inline-flex;
  align-items:center;
  gap:7px;
  font-family:var(--font-display);
  font-weight:800;
  font-size:23px;
  line-height:1;
  letter-spacing:.01em;
}
.rail__mark::after{
  content:"";
  width:7px;height:7px;
  border-radius:50%;
  background:var(--lime);
  box-shadow:0 0 12px rgba(183,255,60,.85);
}
.rail__sub{
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.24em;
  color:var(--mist);
  white-space:nowrap;
}

.nav-toggle{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:9px;
  min-height:44px;
  min-width:44px;
  padding:0 14px;
  border:1px solid #2A4F70;
  border-radius:14px;
  background:rgba(22,58,90,.55);
  color:var(--paper-bright);
  cursor:pointer;
  transition:background .25s var(--ease),border-color .25s var(--ease);
}
.nav-toggle:hover{background:rgba(22,58,90,.9);border-color:#3A6B96}
.nav-toggle__bars{
  position:relative;
  display:block;
  width:18px;height:2px;
  border-radius:2px;
  background:var(--paper-bright);
  transition:background .2s var(--ease);
}
.nav-toggle__bars::before,
.nav-toggle__bars::after{
  content:"";
  position:absolute;
  left:0;
  width:18px;height:2px;
  border-radius:2px;
  background:inherit;
  transition:transform .3s var(--ease),top .3s var(--ease);
}
.nav-toggle__bars::before{top:-6px}
.nav-toggle__bars::after{top:6px}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars{background:transparent}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before{top:0;transform:rotate(45deg);background:var(--orange)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after{top:0;transform:rotate(-45deg);background:var(--orange)}
.nav-toggle__label{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.18em;
  color:var(--paper-bright);
}

.rail__nav{
  position:fixed;
  top:0;left:0;
  z-index:95;
  display:flex;
  flex-direction:column;
  gap:16px;
  width:min(86vw,344px);
  height:100vh;
  height:100dvh;
  padding:calc(var(--topbar-h) + 18px) 16px 28px;
  background:linear-gradient(180deg,var(--ink-800) 0%,var(--ink-900) 100%);
  border-right:1px solid var(--ink-700);
  box-shadow:26px 0 60px rgba(2,8,14,.6);
  overflow-y:auto;
  overscroll-behavior:contain;
  transform:translateX(-102%);
  transition:transform .38s var(--ease);
}
.site-header[data-open] .rail__nav{transform:translateX(0)}

.rail__eyebrow{
  margin:0;
  padding-left:12px;
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.3em;
  color:var(--mist);
}
.rail__list{display:flex;flex-direction:column;gap:4px}
.rail__link{
  position:relative;
  display:flex;
  align-items:center;
  gap:10px;
  min-height:44px;
  padding:10px 12px;
  border-radius:14px;
  color:#C6D7E4;
  font-size:15px;
  font-weight:500;
  letter-spacing:.02em;
  text-decoration:none;
  transition:background .25s var(--ease),color .25s var(--ease),transform .25s var(--ease);
}
.rail__link::before{
  content:"";
  position:absolute;
  left:0;top:50%;
  width:3px;height:0;
  border-radius:3px;
  background:var(--orange);
  transform:translateY(-50%);
  transition:height .28s var(--ease);
}
.rail__link:hover{background:rgba(22,58,90,.8);color:var(--paper-bright);transform:translateX(3px)}
.rail__link[aria-current="page"]{
  background:linear-gradient(90deg,rgba(255,107,44,.22),rgba(22,58,90,.22));
  color:var(--paper-bright);
}
.rail__link[aria-current="page"]::before{height:24px}
.rail__link[aria-current="page"] .rail__num{color:var(--orange)}
.rail__num{
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:600;
  font-variant-numeric:tabular-nums;
  letter-spacing:.06em;
  color:#5E7A92;
  transition:color .25s var(--ease);
}
.rail__text{white-space:nowrap}

.rail__foot{
  margin-top:auto;
  display:flex;
  flex-direction:column;
  gap:12px;
  padding-top:16px;
  border-top:1px dashed rgba(143,166,184,.22);
}
.rail__meta{
  margin:0;
  font-family:var(--font-mono);
  font-size:10px;
  line-height:1.7;
  letter-spacing:.16em;
  color:#6E8AA0;
}

.rail__progress{
  position:absolute;
  left:0;right:0;bottom:0;
  z-index:97;
  height:3px;
  background:rgba(143,166,184,.16);
  overflow:hidden;
}
.rail__progress-bar{
  display:block;
  width:100%;height:100%;
  background:linear-gradient(90deg,var(--lime),var(--orange));
  transform:scaleX(var(--progress,0));
  transform-origin:left center;
  transition:transform .12s linear;
}

.drawer-scrim{
  position:fixed;
  inset:0;
  z-index:80;
  background:rgba(3,10,18,.68);
  backdrop-filter:blur(3px);
  opacity:0;
  pointer-events:none;
  transition:opacity .32s var(--ease);
}
.site-header[data-open] .drawer-scrim{opacity:1;pointer-events:auto}

/* ============ 按钮 ============ */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.6em;
  min-height:48px;
  padding:.85em 1.4em;
  border:1px solid transparent;
  border-radius:var(--radius-pill);
  font-family:var(--font-body);
  font-size:15px;
  font-weight:600;
  letter-spacing:.04em;
  line-height:1.1;
  text-decoration:none;
  cursor:pointer;
  transition:background .25s var(--ease),color .25s var(--ease),border-color .25s var(--ease),transform .25s var(--ease);
}
.btn--primary{background:var(--orange);color:#1A0A02}
.btn--primary:hover{background:#FF8349;transform:translateY(-2px)}
.btn--ghost{border-color:#2A4F70;background:rgba(22,58,90,.45);color:var(--paper-bright)}
.btn--ghost:hover{border-color:var(--lime);color:var(--lime);transform:translateY(-2px)}
.btn--slash{
  width:100%;
  padding:.9em 1.2em;
  border:0;
  border-radius:6px;
  background:linear-gradient(100deg,var(--orange),#FF8A4D);
  color:#1A0A02;
  font-weight:700;
  letter-spacing:.06em;
  clip-path:polygon(0 0,100% 0,calc(100% - 18px) 100%,0 100%);
}
.btn--slash:hover{background:linear-gradient(100deg,#FF8349,var(--amber));transform:translateY(-2px)}

/* ============ 面包屑 ============ */
.breadcrumb{padding:18px 0 6px}
.breadcrumb__list{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  font-family:var(--font-mono);
  font-size:12.5px;
  letter-spacing:.06em;
  color:var(--mist);
}
.breadcrumb__list li{display:flex;align-items:center;gap:8px}
.breadcrumb__list li+li::before{content:"/";color:#3F6280}
.breadcrumb__link{
  color:var(--mist);
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .2s,border-color .2s;
}
.breadcrumb__link:hover{color:var(--paper-bright);border-color:var(--orange)}
.breadcrumb__current{color:var(--peach)}

/* ============ 章节 ============ */
.chapter{position:relative;padding-block:clamp(48px,6vw,96px)}
.chapter__head{
  display:grid;
  grid-template-columns:auto 1fr;
  gap:clamp(14px,3vw,40px);
  align-items:start;
  margin-bottom:clamp(24px,4vw,52px);
}
.chapter__num{
  padding-top:.75em;
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.2em;
  color:var(--orange);
}
.chapter__title{font-size:clamp(1.9rem,4vw,3.4rem)}
.chapter__lead{margin-top:.9em;max-width:52ch;color:var(--mist);font-size:1rem;line-height:1.8}

/* ============ 卡片与标签 ============ */
.card{
  background:linear-gradient(180deg,rgba(22,58,90,.55),rgba(14,39,64,.9));
  border:1px solid #1D4368;
  border-radius:var(--radius-lg);
  padding:clamp(20px,2.4vw,32px);
  transition:transform .3s var(--ease),border-color .3s var(--ease),box-shadow .3s var(--ease);
}
.card:hover{transform:translateY(-3px);border-color:#2C5C86;box-shadow:0 18px 40px rgba(3,12,20,.45)}
.card--paper{background:var(--paper);color:#152A3C;border-color:rgba(18,40,58,.14)}
.card--paper h3,.card--paper h2{color:var(--ink-800)}
.card__title{font-size:clamp(1.1rem,1.5vw,1.35rem);margin-bottom:.4em}
.card__meta{font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;color:var(--mist)}

.capsule{
  display:inline-flex;
  align-items:center;
  gap:.5em;
  min-height:32px;
  padding:.35em .9em;
  border:1px solid #2A4F70;
  border-radius:var(--radius-pill);
  background:rgba(22,58,90,.5);
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.12em;
  color:var(--paper-bright);
  text-decoration:none;
}
.capsule--lime{background:rgba(183,255,60,.14);border-color:rgba(183,255,60,.5);color:var(--lime)}
.capsule--amber{background:rgba(255,176,32,.14);border-color:rgba(255,176,32,.5);color:var(--amber)}
.pill-row{display:flex;flex-wrap:wrap;gap:10px}
.pill{
  min-height:44px;
  padding:.6em 1.1em;
  border:1px solid #2A4F70;
  border-radius:var(--radius-pill);
  background:transparent;
  color:#C6D7E4;
  font-size:14px;
  letter-spacing:.02em;
  cursor:pointer;
  transition:background .22s var(--ease),color .22s var(--ease),border-color .22s var(--ease);
}
.pill:hover{border-color:#3A6B96;color:var(--paper-bright)}
.pill[aria-pressed="true"]{background:var(--lime);border-color:var(--lime);color:#0F2408;font-weight:600}

.stat{display:flex;flex-direction:column;gap:2px}
.stat__value{
  font-family:var(--font-mono);
  font-size:clamp(1.6rem,3vw,2.4rem);
  font-weight:700;
  font-variant-numeric:tabular-nums;
  line-height:1;
  color:var(--lime);
}
.stat__label{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.2em;
  color:var(--mist);
}

/* ============ 图片容器 ============ */
.media{
  position:relative;
  overflow:hidden;
  aspect-ratio:16/10;
  border:1px solid #1D4368;
  border-radius:var(--radius-lg);
  background:linear-gradient(150deg,var(--ink-700),var(--ink-900) 72%);
}
.media img{width:100%;height:100%;object-fit:cover}
.media--wide{aspect-ratio:21/9}
.media--square{aspect-ratio:1/1}
.media--portrait{aspect-ratio:3/4}
.media__caption{
  position:absolute;
  left:14px;right:14px;bottom:12px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  color:var(--paper-bright);
  text-shadow:0 1px 8px rgba(0,0,0,.75);
}

/* ============ 旁注与表格 ============ */
.note{
  padding-left:12px;
  border-left:2px solid var(--orange);
  font-size:13px;
  line-height:1.7;
  color:var(--mist);
}
.note--vertical{
  writing-mode:vertical-rl;
  text-orientation:mixed;
  padding:0;
  border-left:0;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.24em;
  color:var(--mist);
}
.table-wrap{
  overflow-x:auto;
  border:1px solid #1D4368;
  border-radius:var(--radius-md);
  background:rgba(14,39,64,.6);
}
.data-table{width:100%;min-width:520px;border-collapse:collapse;font-size:15px}
.data-table th,.data-table td{padding:14px 16px;text-align:left;border-bottom:1px solid rgba(143,166,184,.14)}
.data-table th{
  background:var(--ink-800);
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:600;
  letter-spacing:.18em;
  color:var(--mist);
}
.data-table td{font-variant-numeric:tabular-nums;color:#D3E0EB}
.data-table tbody tr:last-child td{border-bottom:0}

/* ============ 显现 ============ */
[data-reveal]{
  opacity:0;
  transform:translateY(18px);
  transition:opacity .7s var(--ease),transform .7s var(--ease);
}
[data-reveal].is-in{opacity:1;transform:none}

/* ============ 页脚 ============ */
.site-footer{
  position:relative;
  margin-top:clamp(56px,8vw,110px);
  background:linear-gradient(180deg,#081F33 0%,#05131F 100%);
  border-top:1px solid var(--ink-700);
}
.footer__stripe{
  height:16px;
  background:linear-gradient(90deg,var(--orange) 0%,var(--amber) 42%,var(--lime) 100%);
  clip-path:polygon(0 0,100% 0,100% 34%,0 100%);
}
.footer__inner{
  display:grid;
  grid-template-columns:1fr;
  gap:clamp(28px,4vw,44px);
  max-width:var(--content-max);
  margin-inline:auto;
  padding:clamp(36px,5vw,72px) var(--gutter) clamp(26px,4vw,48px);
}
.footer__brand{display:flex;flex-direction:column;align-items:flex-start;gap:14px}
.footer__wordmark{
  font-family:var(--font-display);
  font-weight:800;
  font-size:clamp(2.4rem,6vw,3.6rem);
  line-height:.9;
  letter-spacing:-.02em;
  color:var(--paper-bright);
}
.footer__wordmark span{
  margin-left:.14em;
  font-size:.48em;
  vertical-align:middle;
  letter-spacing:.06em;
  color:var(--orange);
}
.footer__tagline{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.2em;
  color:var(--mist);
}
.footer__cta{margin-top:4px}
.footer__grid{display:grid;grid-template-columns:1fr;gap:26px}
.footer__col{min-width:0}
.footer__heading{
  margin-bottom:14px;
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:600;
  letter-spacing:.24em;
  text-transform:uppercase;
  color:var(--peach);
}
.footer__list{display:flex;flex-direction:column;gap:10px}
.footer__link{
  display:inline-flex;
  align-items:center;
  min-height:32px;
  font-size:15px;
  color:#CBDCE8;
  text-decoration:none;
  transition:color .2s var(--ease),transform .2s var(--ease);
}
.footer__link:hover{color:var(--lime);transform:translateX(3px)}
.footer__contact{display:flex;flex-direction:column}
.footer__contact-row{
  display:flex;
  flex-direction:column;
  gap:2px;
  padding:10px 0;
  border-bottom:1px dashed rgba(143,166,184,.22);
}
.footer__label{
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.24em;
  color:#6E8AA0;
}
.footer__value{font-size:14px;color:var(--paper-bright);word-break:break-word}
.footer__note{
  margin-top:14px;
  max-width:34ch;
  font-size:12.5px;
  line-height:1.75;
  color:var(--mist);
}
.footer__legal{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  max-width:var(--content-max);
  margin-inline:auto;
  padding:18px var(--gutter) 26px;
  border-top:1px solid rgba(143,166,184,.16);
}
.footer__legal-text{
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.1em;
  color:#6E8AA0;
}
.footer__legal-links{display:flex;flex-wrap:wrap;gap:16px}
.footer__legal-link{
  font-size:12.5px;
  color:var(--mist);
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .2s,border-color .2s;
}
.footer__legal-link:hover{color:var(--lime);border-color:rgba(183,255,60,.5)}

/* ============ 响应式 ============ */
@media (max-width:479px){
  .rail__sub{display:none}
}
@media (max-width:639px){
  .chapter__head{grid-template-columns:1fr;gap:8px}
  .chapter__num{padding-top:0}
  .note--vertical{
    writing-mode:horizontal-tb;
    padding-left:10px;
    border-left:2px solid var(--orange);
    letter-spacing:.1em;
  }
}
@media (min-width:768px){
  .footer__inner{grid-template-columns:minmax(0,1fr) minmax(0,1.7fr)}
  .footer__grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
}
@media (min-width:768px) and (max-width:1179px){
  .footer__contact{grid-column:1 / -1}
}
@media (min-width:1024px){
  body{padding-top:0;padding-left:var(--rail-w)}
  #main-content{scroll-margin-top:12px}
  .rail{
    top:0;left:0;bottom:0;right:auto;
    width:var(--rail-w);
    height:auto;
    border-bottom:0;
    border-right:1px solid var(--ink-700);
    background:linear-gradient(180deg,var(--ink-800) 0%,#081F33 55%,var(--ink-900) 100%);
    box-shadow:none;
  }
  .skip-link{left:calc(var(--rail-w) + 16px)}
  .rail__top{
    flex:0 0 auto;
    flex-direction:column;
    align-items:flex-start;
    justify-content:flex-start;
    gap:8px;
    padding:26px 20px 20px;
    border-bottom:1px solid rgba(143,166,184,.18);
  }
  .rail__brand{flex-direction:column;align-items:flex-start;gap:6px}
  .rail__mark{font-size:26px}
  .nav-toggle{display:none}
  .rail__nav{
    position:static;
    transform:none;
    width:auto;
    height:auto;
    flex:1 1 auto;
    padding:20px 14px 24px;
    background:transparent;
    border-right:0;
    box-shadow:none;
    z-index:auto;
  }
  .drawer-scrim{display:none}
  .rail__progress{
    top:0;bottom:0;left:auto;right:0;
    width:3px;height:100%;
  }
  .rail__progress-bar{
    transform:scaleY(var(--progress,0));
    transform-origin:center top;
    background:linear-gradient(180deg,var(--lime),var(--orange));
  }
}
@media (min-width:1180px){
  .footer__inner{
    grid-template-columns:minmax(0,1fr) minmax(0,1.9fr) minmax(240px,1fr);
    align-items:start;
  }
  .footer__contact{grid-column:auto}
}
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  [data-reveal]{opacity:1 !important;transform:none !important}
  .rail__link:hover,.footer__link:hover,.btn:hover{transform:none}
}