:root{
  --paper:#F8F6EF;
  --fog:#E4E8E2;
  --kraft:#EFE6D4;
  --ink:#1C241F;
  --jade:#1D7A5B;
  --jade-deep:#145B43;
  --amber:#C28A2C;
  --amber-deep:#7A4D0F;
  --coral:#D96C55;
  --jade-pale:#CFE5DB;
  --sage:#93A99C;
  --line:rgba(28,36,31,.16);
  --line-soft:rgba(28,36,31,.08);
  --muted:rgba(28,36,31,.7);
  --shell:1240px;
  --gutter:clamp(16px,4vw,40px);
  --font-head:"HarmonyOS Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"HarmonyOS Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"IBM Plex Mono","JetBrains Mono",SFMono-Regular,Consolas,"Courier New",monospace;
  --shadow-k:6px 6px 0 rgba(28,36,31,.14);
  --shadow-h:8px 8px 0 rgba(28,36,31,.2);
  --t-fast:160ms;
  --t-mid:240ms;
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:132px}
body,h1,h2,h3,h4,p,ul,ol,figure,dl,dd{margin:0}
ul,ol{padding-left:1.15em}
img,svg{max-width:100%;display:block}
button{font:inherit;color:inherit}
table{border-collapse:collapse}

body{
  background-color:var(--paper);
  background-image:radial-gradient(circle at 1px 1px,rgba(28,36,31,.055) 1px,transparent 0);
  background-size:26px 26px;
  color:var(--ink);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.75;
  font-weight:400;
  -webkit-font-smoothing:antialiased;
}

h1,h2,h3,h4{font-family:var(--font-head);font-weight:700;line-height:1.28;letter-spacing:-.01em}
h1{font-size:clamp(32px,4.4vw,44px);font-weight:800}
h2{font-size:clamp(24px,2.8vw,32px);font-weight:800}
h3{font-size:clamp(19px,1.8vw,22px);font-weight:700}
strong{font-weight:700}
a{color:var(--jade-deep);text-underline-offset:3px}
a:hover{color:var(--jade)}
p{max-width:42em}
::selection{background:var(--jade-pale);color:var(--ink)}

:focus-visible{outline:3px solid var(--amber);outline-offset:2px}

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

/* ============ 布局基础 ============ */
.shell{width:100%;max-width:var(--shell);margin-inline:auto;padding-inline:var(--gutter)}
.page-main{padding-bottom:clamp(40px,6vw,72px)}
.stack{display:flex;flex-direction:column;gap:16px}
.cluster{display:flex;flex-wrap:wrap;align-items:center;gap:12px}
.grid-12{display:grid;grid-template-columns:repeat(12,1fr);gap:clamp(14px,2vw,24px)}

/* ============ 文字部件 ============ */
.eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:12px;line-height:1.4;
  letter-spacing:.16em;text-transform:uppercase;color:var(--jade-deep);
}
.eyebrow::before{content:"";width:9px;height:9px;background:var(--amber);display:inline-block;flex:0 0 auto}
.lede{font-size:17px;line-height:1.8;color:var(--muted);max-width:42em}

.section{margin-block:clamp(32px,5vw,56px)}
.section__head{
  display:flex;flex-wrap:wrap;align-items:baseline;justify-content:space-between;
  gap:10px 20px;padding-bottom:10px;margin-bottom:22px;
  border-bottom:2px solid var(--ink);
}
.section__title{font-size:clamp(22px,2.6vw,30px);font-weight:800;margin:0}

/* ============ 按钮 ============ */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:11px 20px;border:2px solid var(--ink);border-radius:0;
  font-family:var(--font-head);font-size:15px;font-weight:700;letter-spacing:.01em;
  text-decoration:none;cursor:pointer;background:var(--paper);color:var(--ink);
  box-shadow:4px 4px 0 var(--ink);
  transition:transform var(--t-fast) ease,box-shadow var(--t-fast) ease,background-color var(--t-fast) ease,color var(--t-fast) ease;
}
.btn:hover{transform:translate(-1px,-1px);box-shadow:6px 6px 0 var(--ink);color:var(--ink)}
.btn:active{transform:translate(1px,1px);box-shadow:2px 2px 0 var(--ink)}
.btn--jade{background:var(--jade);color:var(--paper);border-color:var(--ink)}
.btn--jade:hover{background:var(--jade-deep);color:var(--paper)}
.btn--ink{background:var(--ink);color:var(--paper);border-color:var(--ink)}
.btn--ink:hover{background:var(--jade-deep);color:var(--paper)}
.btn--ghost{background:transparent;border-color:var(--ink);box-shadow:none}
.btn--ghost:hover{background:var(--jade-pale);box-shadow:3px 3px 0 var(--ink)}

/* ============ 标签 ============ */
.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:3px 9px;border:1px solid currentColor;border-radius:0;
  font-family:var(--font-mono);font-size:11px;line-height:1.6;letter-spacing:.08em;
  color:var(--amber-deep);background:rgba(194,138,44,.1);
}
.tag--jade{color:var(--jade-deep);background:var(--jade-pale);border-color:var(--jade)}
.tag--amber{color:var(--amber-deep);background:rgba(194,138,44,.12);border-color:var(--amber)}
.tag--coral{color:#7c3325;background:rgba(217,108,85,.16);border-color:var(--coral)}

/* ============ 卡片 ============ */
.card{
  position:relative;
  background:var(--kraft);
  border:2px solid var(--ink);
  box-shadow:var(--shadow-k);
  padding:clamp(18px,2.4vw,26px);
  transition:transform var(--t-fast) ease,box-shadow var(--t-fast) ease,background-color var(--t-fast) ease;
}
.card:hover,.card:focus-within{transform:translateY(-2px);box-shadow:var(--shadow-h);background:#F4EDDE}
.card__label{
  display:block;margin-bottom:8px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.16em;text-transform:uppercase;color:var(--amber-deep);
}
.card__title{font-family:var(--font-head);font-size:20px;font-weight:700;line-height:1.4;margin-bottom:8px}
.card__body{font-size:15px;line-height:1.78;color:var(--muted);max-width:none}

/* ============ 面包屑 ============ */
.breadcrumb{margin-block:18px 0}
.breadcrumb__list{display:flex;flex-wrap:wrap;align-items:center;gap:8px;list-style:none;padding:0;margin:0}
.breadcrumb__list li{display:inline-flex;align-items:center;gap:8px;font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;color:var(--sage)}
.breadcrumb__list li+li::before{content:"/";color:var(--sage)}
.breadcrumb__link{color:var(--jade-deep);text-decoration:none;border-bottom:1px solid transparent;transition:border-color var(--t-fast) ease,color var(--t-fast) ease}
.breadcrumb__link:hover{color:var(--jade);border-bottom-color:var(--jade)}
.breadcrumb__current{color:var(--muted)}

/* ============ 媒体容器 ============ */
.media-frame{background:var(--paper);border:2px solid var(--ink);box-shadow:var(--shadow-k);margin:0}
.media-frame__inner{
  position:relative;aspect-ratio:16/9;overflow:hidden;
  background-color:var(--jade-pale);
  background-image:
    repeating-linear-gradient(0deg,rgba(28,36,31,.07) 0 1px,transparent 1px 26px),
    repeating-linear-gradient(90deg,rgba(28,36,31,.07) 0 1px,transparent 1px 26px),
    linear-gradient(135deg,rgba(248,246,239,.9),rgba(239,230,212,.65));
}
.media-frame__inner::before{
  content:"";position:absolute;inset:12px 12px auto auto;width:34px;height:3px;background:var(--amber);opacity:.85;
}
.media-frame__inner>img,.media-frame__inner>picture>img{width:100%;height:100%;object-fit:cover;display:block}
.media-frame__caption{
  display:block;padding:8px 12px;border-top:2px solid var(--ink);background:var(--paper);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;color:var(--muted);
}
.media-frame--wide .media-frame__inner{aspect-ratio:21/9}
.media-frame--square .media-frame__inner{aspect-ratio:1/1}

/* ============ 页内索引 ============ */
.toc{position:sticky;top:118px;display:flex;flex-direction:column;gap:2px;border-left:2px solid var(--line);padding-left:12px}
.toc__title{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.18em;text-transform:uppercase;
  color:var(--amber-deep);margin-bottom:8px;
}
.toc__list{list-style:none;padding:0;margin:0;display:flex;flex-direction:column;gap:2px}
.toc__link{
  display:block;padding:6px 0;font-family:var(--font-mono);font-size:12px;line-height:1.5;
  letter-spacing:.04em;color:var(--muted);text-decoration:none;
  border-left:2px solid transparent;margin-left:-14px;padding-left:12px;
  transition:color var(--t-fast) ease,border-color var(--t-fast) ease,background-color var(--t-fast) ease;
}
.toc__link:hover{color:var(--jade-deep)}
.toc__link.is-active{color:var(--jade-deep);border-left-color:var(--jade);background:var(--jade-pale)}

/* ============ 跳过链接 ============ */
.skip-link{
  position:absolute;left:12px;top:8px;z-index:200;
  padding:10px 16px;background:var(--ink);color:var(--paper);
  border:2px solid var(--amber);font-family:var(--font-mono);font-size:13px;letter-spacing:.06em;
  text-decoration:none;transform:translateY(-160%);
  transition:transform var(--t-fast) ease;
}
.skip-link:focus{transform:translateY(0);color:var(--paper)}

/* ============ 页头 ============ */
.site-header{
  position:sticky;top:0;z-index:90;
  background:var(--paper);
  border-bottom:2px solid var(--ink);
}
.header-rail{
  background:var(--ink);color:var(--paper);overflow:hidden;
  max-height:44px;border-bottom:1px solid rgba(248,246,239,.16);
  transition:max-height var(--t-mid) ease,opacity 180ms ease;
}
.site-header.is-condensed .header-rail{max-height:0;opacity:0;border-bottom-width:0}
.header-rail__inner{
  display:flex;align-items:center;gap:16px;
  width:100%;max-width:var(--shell);margin-inline:auto;padding-inline:var(--gutter);
  height:42px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.1em;
}
.rail-tag{display:inline-flex;align-items:center;gap:8px;color:var(--jade-pale);white-space:nowrap}
.rail-dot{width:8px;height:8px;background:var(--coral);display:inline-block;flex:0 0 auto}
.rail-meta{color:rgba(248,246,239,.74);white-space:nowrap}
.rail-meta--right{color:rgba(248,246,239,.58)}
.rail-scale{
  flex:1 1 40px;min-width:36px;height:9px;
  background-image:repeating-linear-gradient(90deg,var(--amber) 0 1px,transparent 1px 13px);
  opacity:.6;
}

.header-bar{
  display:flex;align-items:center;justify-content:space-between;gap:18px;
  width:100%;max-width:var(--shell);margin-inline:auto;
  padding:12px var(--gutter);
}

.brand{display:flex;align-items:center;gap:12px;flex:0 1 auto;text-decoration:none;color:var(--ink)}
.brand:hover{color:var(--ink)}
.brand__mark{
  display:grid;grid-template-columns:repeat(2,1fr);grid-template-rows:repeat(2,1fr);
  gap:3px;width:38px;height:38px;padding:4px;flex:0 0 auto;
  border:2px solid var(--ink);background:var(--kraft);box-shadow:3px 3px 0 var(--ink);
}
.brand__pip{display:block;background:var(--jade)}
.brand__pip:nth-child(2){background:var(--amber)}
.brand__pip:nth-child(3){background:var(--sage)}
.brand__pip:nth-child(4){background:var(--ink)}
.brand__text{display:flex;flex-direction:column;line-height:1.2;min-width:0}
.brand__name{font-family:var(--font-head);font-size:21px;font-weight:800;letter-spacing:.02em}
.brand__subline{font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;color:var(--jade-deep);margin-top:2px}

.site-nav{display:flex;align-items:center;gap:18px}
.site-nav__list{display:flex;align-items:center;gap:2px;list-style:none;padding:0;margin:0}
.site-nav__item{display:block}
.site-nav__link{
  display:inline-flex;align-items:baseline;gap:6px;
  padding:8px 10px;border:2px solid transparent;border-radius:0;
  color:var(--ink);text-decoration:none;font-family:var(--font-head);
  font-size:15px;font-weight:600;letter-spacing:0;
  transition:background-color var(--t-fast) ease,border-color var(--t-fast) ease,color var(--t-fast) ease;
}
.site-nav__link:hover{background:var(--jade-pale);border-color:var(--ink);color:var(--ink)}
.site-nav__num{font-family:var(--font-mono);font-size:10px;font-weight:500;letter-spacing:.08em;color:var(--amber-deep)}
.site-nav__link[aria-current="page"]{
  background:var(--jade-pale);border-color:var(--ink);color:var(--jade-deep);
  box-shadow:inset 0 -3px 0 var(--jade);
}
.site-nav__link[aria-current="page"] .site-nav__num{color:var(--jade-deep)}
.site-nav__cta{flex:0 0 auto}

.nav-toggle{
  display:none;align-items:center;gap:8px;
  padding:7px 11px;border:2px solid var(--ink);border-radius:0;
  background:var(--paper);color:var(--ink);box-shadow:3px 3px 0 var(--ink);
  font-family:var(--font-mono);font-size:12px;letter-spacing:.1em;cursor:pointer;
  transition:background-color var(--t-fast) ease,transform var(--t-fast) ease,box-shadow var(--t-fast) ease;
}
.nav-toggle:hover{background:var(--jade-pale)}
.nav-toggle:active{transform:translate(1px,1px);box-shadow:1px 1px 0 var(--ink)}
.nav-toggle__bars{display:flex;flex-direction:column;gap:3px}
.nav-toggle__bar{display:block;width:16px;height:2px;background:var(--ink);transition:transform var(--t-fast) ease,opacity var(--t-fast) ease}
.site-header[data-open] .nav-toggle{background:var(--jade-pale)}
.site-header[data-open] .nav-toggle__bar:nth-child(1){transform:translateY(5px) rotate(45deg)}
.site-header[data-open] .nav-toggle__bar:nth-child(2){opacity:0}
.site-header[data-open] .nav-toggle__bar:nth-child(3){transform:translateY(-5px) rotate(-45deg)}
.nav-toggle__label{line-height:1}

.scroll-progress{
  position:absolute;left:0;bottom:-2px;width:100%;height:3px;z-index:2;
  background:linear-gradient(90deg,var(--jade),var(--amber));
  transform:scaleX(0);transform-origin:0 50%;
  pointer-events:none;
  transition:transform 120ms linear;
}

/* ============ 页脚 ============ */
.site-footer{
  margin-top:clamp(48px,7vw,88px);
  background:var(--ink);
  color:var(--paper);
  border-top:2px solid var(--ink);
  background-image:repeating-linear-gradient(0deg,rgba(248,246,239,.045) 0 1px,transparent 1px 30px);
}
.footer-top{
  display:grid;grid-template-columns:1.5fr 1fr 1fr 1.35fr;gap:32px 28px;
  width:100%;max-width:var(--shell);margin-inline:auto;
  padding:clamp(32px,4vw,52px) var(--gutter) 32px;
  border-bottom:1px solid rgba(248,246,239,.18);
}
.footer-brand{display:block}
.footer-brand__mark{display:inline-flex;gap:4px;margin-bottom:14px}
.footer-brand__pip{display:block;width:12px;height:12px;background:var(--jade)}
.footer-brand__pip:nth-child(2){background:var(--amber)}
.footer-brand__pip:nth-child(3){background:var(--coral)}
.footer-brand__name{font-family:var(--font-head);font-size:23px;font-weight:800;letter-spacing:.02em;color:var(--paper)}
.footer-brand__sub{margin-top:8px;font-size:14px;line-height:1.8;color:rgba(248,246,239,.72);max-width:24em}
.footer-brand__version{
  margin-top:14px;font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;
  color:var(--amber);
}
.footer-col{min-width:0}
.footer-col__title{
  font-family:var(--font-mono);font-size:11px;font-weight:600;letter-spacing:.2em;text-transform:uppercase;
  color:var(--amber);margin-bottom:14px;
}
.footer-col__list{list-style:none;padding:0;margin:0;display:flex;flex-direction:column;gap:9px}
.footer-col__link{
  color:rgba(248,246,239,.84);text-decoration:none;font-size:14px;line-height:1.6;
  border-bottom:1px solid transparent;
  transition:color var(--t-fast) ease,border-color var(--t-fast) ease;
}
.footer-col__link:hover{color:var(--jade-pale);border-bottom-color:var(--jade-pale)}
.footer-col--contact .footer-contact__row{display:flex;gap:10px;font-size:13px;line-height:1.7;margin-bottom:8px}
.footer-contact__key{
  flex:0 0 34px;font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;
  color:var(--sage);padding-top:1px;
}
.footer-contact__val{color:rgba(248,246,239,.86);word-break:break-word;min-width:0}
.footer-legal{
  display:flex;flex-wrap:wrap;align-items:center;gap:10px 24px;
  width:100%;max-width:var(--shell);margin-inline:auto;
  padding:16px var(--gutter) 24px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.04em;line-height:1.7;
}
.footer-legal__meta{color:rgba(248,246,239,.6);max-width:none}
.footer-legal__note{color:rgba(248,246,239,.5);max-width:none}
.to-top{
  margin-left:auto;padding:7px 14px;border:1px solid var(--amber);border-radius:0;
  background:transparent;color:var(--paper);cursor:pointer;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;
  transition:background-color var(--t-fast) ease,color var(--t-fast) ease;
}
.to-top:hover{background:var(--amber);color:var(--ink)}
.to-top[hidden]{display:none}

/* ============ 响应式 ============ */
@media (max-width:1080px){
  .footer-top{grid-template-columns:1.4fr 1fr 1fr;gap:28px}
  .footer-col--contact{grid-column:1 / -1;border-top:1px solid rgba(248,246,239,.16);padding-top:20px}
}

@media (max-width:980px){
  html{scroll-padding-top:104px}
  .nav-toggle{display:inline-flex}
  .site-nav{
    position:absolute;top:100%;left:0;right:0;
    display:none;flex-direction:column;align-items:stretch;gap:0;
    padding:10px var(--gutter) 20px;
    background:var(--paper);
    border-top:2px solid var(--ink);
    border-bottom:2px solid var(--ink);
    box-shadow:0 18px 0 rgba(28,36,31,.1);
  }
  .site-header[data-open] .site-nav{display:flex}
  .site-nav__list{flex-direction:column;align-items:stretch;gap:0}
  .site-nav__link{
    justify-content:flex-start;width:100%;padding:13px 4px;font-size:16px;
    border:0;border-bottom:1px solid var(--line);
  }
  .site-nav__link:hover{background:var(--jade-pale);border-color:var(--line)}
  .site-nav__link[aria-current="page"]{box-shadow:inset 3px 0 0 var(--jade);border-bottom:2px solid var(--jade)}
  .site-nav__cta{margin-top:14px;width:100%}
  .header-rail__inner{font-size:11px;gap:12px}
  .rail-meta--right{display:none}
  .grid-12{grid-template-columns:repeat(6,1fr)}
}

@media (max-width:720px){
  body{font-size:15.5px}
  .header-rail{max-height:38px}
  .header-rail__inner{height:36px;letter-spacing:.06em}
  .rail-scale{display:none}
  .brand__mark{width:34px;height:34px}
  .brand__name{font-size:19px}
  .brand__subline{font-size:10px;letter-spacing:.08em}
  .footer-top{grid-template-columns:1fr 1fr;gap:26px 20px}
  .footer-brand{grid-column:1 / -1}
  .footer-col--contact{grid-column:1 / -1}
  .footer-legal{flex-direction:column;align-items:flex-start;gap:8px}
  .to-top{margin-left:0}
  .grid-12{grid-template-columns:1fr}
  .toc{position:static;border-left:0;padding-left:0;border-top:2px solid var(--line);padding-top:12px}
  .toc__link{margin-left:0;padding-left:10px;border-left:2px solid var(--line)}
  .toc__link.is-active{border-left-color:var(--jade)}
}

@media (max-width:480px){
  .footer-top{grid-template-columns:1fr}
  .section__head{flex-direction:column;align-items:flex-start}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms!important;
    animation-iteration-count:1!important;
    transition-duration:.001ms!important;
  }
}