/* ===== 亿万28 · 共享样式 /assets/site.css ===== */

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
body,h1,h2,h3,h4,h5,p,figure,blockquote,dl,dd,ul,ol{margin:0}
ul,ol{padding:0;list-style:none}
img,svg,video{max-width:100%;display:block}
button,input,select,textarea{font:inherit;color:inherit;background:none}
button{border:0;cursor:pointer}
a{color:inherit;text-decoration:none}
table{border-collapse:collapse}

/* ---------- 2. 变量 ---------- */
:root{
  --yw-graphite:#12151A;
  --yw-graphite-2:#1D232B;
  --yw-graphite-3:#252C35;
  --yw-line:#39424D;
  --yw-paper:#F1EDE4;
  --yw-paper-2:#FAF8F3;
  --yw-signal:#FF6A1A;
  --yw-signal-light:#FF8340;
  --yw-signal-deep:#C2470A;
  --yw-electric:#2E9BFF;
  --yw-electric-deep:#0E5A9C;
  --yw-ink:#0A0C0F;
  --yw-muted:#A8B2BD;
  --yw-paper-line:#D9D2C2;
  --yw-paper-muted:#6B6459;

  --yw-font-sans:"PingFang SC","Hiragino Sans GB","Microsoft YaHei",Inter,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --yw-font-serif:"Noto Serif SC","Source Han Serif SC","Songti SC",Georgia,serif;
  --yw-font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --yw-gutter:clamp(20px,4.5vw,72px);
  --yw-max:1300px;
  --yw-header-h:124px;
  --yw-radius:2px;
  --yw-gap:18px;
}

/* ---------- 3. 基础排版 ---------- */
body{
  background:var(--yw-graphite);
  color:var(--yw-paper);
  font-family:var(--yw-font-sans);
  font-size:16px;
  font-weight:400;
  line-height:1.75;
  padding-top:var(--yw-header-h);
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
#main-content{scroll-margin-top:var(--yw-header-h)}
strong,b{font-weight:700}
small{font-size:13px}
code,kbd,samp{font-family:var(--yw-font-mono);font-size:.92em}

.yw-h1{font-family:var(--yw-font-sans);font-weight:900;font-size:clamp(32px,5.4vw,72px);line-height:1.05;letter-spacing:-.02em}
.yw-h2{font-family:var(--yw-font-sans);font-weight:900;font-size:clamp(25px,3.1vw,42px);line-height:1.14;letter-spacing:-.015em}
.yw-h3{font-family:var(--yw-font-serif);font-weight:600;font-size:clamp(19px,2vw,28px);line-height:1.38;letter-spacing:.005em}
.yw-lead{font-size:clamp(16.5px,1.35vw,19px);line-height:1.85;color:var(--yw-muted);max-width:62ch}
.yw-kicker{font-family:var(--yw-font-mono);font-size:12.5px;letter-spacing:.14em;color:var(--yw-signal);text-transform:uppercase}
.yw-num{
  font-family:var(--yw-font-mono);
  font-weight:700;
  font-size:clamp(44px,9vw,128px);
  line-height:.86;
  letter-spacing:-.05em;
  color:#1F262E;
  -webkit-text-stroke:1px var(--yw-line);
}

/* ---------- 4. 布局工具 ---------- */
.yw-wrap{width:min(calc(100% - var(--yw-gutter) * 2),var(--yw-max));margin-inline:auto}
.yw-section{padding-block:clamp(48px,7vw,96px)}
.yw-section--tight{padding-block:clamp(30px,4vw,56px)}
.yw-stack>*+*{margin-top:var(--yw-gap)}
.yw-sr{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}

.yw-grid{display:grid;gap:clamp(20px,3vw,44px);align-items:start}
.yw-grid--4-8{grid-template-columns:4fr 8fr}
.yw-grid--5-7{grid-template-columns:5fr 7fr}
.yw-grid--7-5{grid-template-columns:7fr 5fr}
.yw-grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.yw-grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}

/* ---------- 5. 跳过链接 ---------- */
.yw-skip{
  position:fixed;top:0;left:-9999px;z-index:300;
  background:var(--yw-signal);color:var(--yw-ink);
  font-size:14px;font-weight:700;letter-spacing:.04em;
  padding:13px 22px;border-radius:0 0 var(--yw-radius) 0;
}
.yw-skip:focus{left:0}

/* ---------- 6. 页头 ---------- */
.yw-header{
  position:fixed;top:0;left:0;right:0;z-index:120;
  background:transparent;
  color:var(--yw-paper);
  transition:background-color .26s ease,box-shadow .26s ease;
}
.yw-header::after{
  content:"";position:absolute;left:0;right:0;bottom:0;height:1px;
  background:var(--yw-line);opacity:0;transition:opacity .26s ease;
}
.yw-header[data-stuck]{
  background:rgba(18,21,26,.96);
  box-shadow:0 18px 40px rgba(0,0,0,.42);
}
.yw-header[data-stuck]::after{opacity:1}

.yw-header__inner{
  display:flex;align-items:center;gap:clamp(14px,2.4vw,40px);
  min-height:76px;
}

/* 品牌 */
.yw-brand{display:flex;flex-direction:column;gap:1px;flex:0 0 auto;margin-right:auto}
.yw-brand__mark{font-size:22px;font-weight:900;letter-spacing:-.02em;line-height:1.15}
.yw-brand__mark::after{
  content:"";display:inline-block;width:7px;height:7px;margin-left:8px;
  background:var(--yw-signal);vertical-align:middle;transform:translateY(-2px);
}
.yw-brand__line{font-family:var(--yw-font-mono);font-size:11px;letter-spacing:.1em;color:var(--yw-muted);line-height:1.4}

/* 主导航 */
.yw-nav{margin-left:auto}
.yw-nav__list{display:flex;align-items:center;gap:clamp(10px,1.7vw,28px)}
.yw-nav__link{
  position:relative;display:block;padding:9px 2px;
  font-size:14.5px;font-weight:500;letter-spacing:.01em;
  color:var(--yw-paper);opacity:.76;
  transition:opacity .18s ease,color .18s ease;
}
.yw-nav__link:hover{opacity:1;color:var(--yw-electric)}
.yw-nav__link[aria-current="page"]{opacity:1;color:var(--yw-paper)}
.yw-nav__link[aria-current="page"]::after{
  content:"";position:absolute;left:0;right:0;bottom:0;height:2px;background:var(--yw-signal);
}

/* 页头右侧 */
.yw-header__aside{display:flex;align-items:center;gap:clamp(10px,1.4vw,18px);flex:0 0 auto}
.yw-header__phone{
  font-family:var(--yw-font-mono);font-size:13px;letter-spacing:.04em;
  color:var(--yw-paper);padding-bottom:2px;
  border-bottom:1px dashed var(--yw-line);
  transition:color .18s ease,border-color .18s ease;
}
.yw-header__phone:hover{color:var(--yw-signal);border-color:var(--yw-signal)}

/* 菜单按钮 */
.yw-navtoggle{
  display:none;align-items:center;gap:9px;
  padding:9px 14px;
  border:1px solid var(--yw-line);border-radius:var(--yw-radius);
  color:var(--yw-paper);font-size:13px;font-weight:600;letter-spacing:.06em;
  transition:border-color .18s ease,color .18s ease;
}
.yw-navtoggle:hover{border-color:var(--yw-electric);color:var(--yw-electric)}
.yw-navtoggle__bars{position:relative;display:block;width:16px;height:2px;background:currentColor}
.yw-navtoggle__bars::before,
.yw-navtoggle__bars::after{
  content:"";position:absolute;left:0;width:16px;height:2px;background:currentColor;
  transition:transform .2s ease,opacity .2s ease;
}
.yw-navtoggle__bars::before{top:-5px}
.yw-navtoggle__bars::after{top:5px}
.yw-navtoggle[aria-expanded="true"] .yw-navtoggle__bars{background:transparent}
.yw-navtoggle[aria-expanded="true"] .yw-navtoggle__bars::before{transform:translateY(5px) rotate(45deg)}
.yw-navtoggle[aria-expanded="true"] .yw-navtoggle__bars::after{transform:translateY(-5px) rotate(-45deg)}

/* 次要信息行 */
.yw-header__meta{
  max-height:46px;overflow:hidden;
  border-top:1px solid rgba(57,66,77,.55);
  transition:max-height .28s ease,opacity .22s ease;
}
.yw-header__metaInner{
  display:flex;align-items:center;gap:28px;min-height:44px;
  font-family:var(--yw-font-mono);font-size:12px;letter-spacing:.04em;color:var(--yw-muted);
}
.yw-header__tagline{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.yw-header__tagline::before{content:"[";color:var(--yw-signal)}
.yw-header__tagline::after{content:"]";color:var(--yw-signal)}
.yw-header__note{margin-left:auto;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.yw-header[data-stuck] .yw-header__meta{max-height:0;opacity:0}

/* 阅读进度条 */
.yw-progress{position:absolute;left:0;right:0;bottom:0;height:2px;pointer-events:none;background:transparent}
.yw-progress__bar{display:block;height:100%;width:0;background:var(--yw-signal)}

/* ---------- 7. 按钮 ---------- */
.yw-btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.5em;
  padding:13px 24px;
  font-size:15px;font-weight:600;letter-spacing:.02em;line-height:1.2;
  border:1px solid transparent;border-radius:var(--yw-radius);
  transition:background-color .18s ease,color .18s ease,border-color .18s ease;
}
.yw-btn--signal{background:var(--yw-signal);color:#12151A}
.yw-btn--signal:hover{background:var(--yw-signal-light)}
.yw-btn--blue{background:var(--yw-electric);color:#08131D}
.yw-btn--blue:hover{background:#57B0FF}
.yw-btn--ghost{border-color:var(--yw-line);color:var(--yw-paper)}
.yw-btn--ghost:hover{border-color:var(--yw-electric);color:var(--yw-electric)}
.yw-btn--sm{padding:9px 17px;font-size:13.5px}

/* ---------- 8. 面包屑 ---------- */
.yw-crumb{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  font-family:var(--yw-font-mono);font-size:12px;letter-spacing:.05em;color:var(--yw-muted);
}
.yw-crumb>li{display:flex;align-items:center;gap:8px}
.yw-crumb>li+li::before{content:"/";color:var(--yw-line)}
.yw-crumb a{transition:color .18s ease}
.yw-crumb a:hover{color:var(--yw-electric)}
.yw-crumb [aria-current="page"]{color:var(--yw-paper)}

/* ---------- 9. 通用组件 ---------- */
.yw-band{
  height:6px;
  background:linear-gradient(90deg,
    var(--yw-signal) 0 27%,
    var(--yw-graphite-2) 27% 30%,
    var(--yw-electric) 30% 62%,
    var(--yw-graphite-2) 62% 65%,
    var(--yw-line) 65% 100%);
}

.yw-tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 10px;border:1px solid var(--yw-line);border-radius:var(--yw-radius);
  font-family:var(--yw-font-mono);font-size:12px;letter-spacing:.05em;
  color:var(--yw-muted);line-height:1.5;
}
.yw-tag--signal{border-color:rgba(255,106,26,.55);color:var(--yw-signal)}
.yw-tag--blue{border-color:rgba(46,155,255,.55);color:var(--yw-electric)}

.yw-table{width:100%;font-size:14px;line-height:1.65}
.yw-table th,.yw-table td{padding:10px 14px;text-align:left;vertical-align:top;border-bottom:1px solid var(--yw-line)}
.yw-table thead th{
  font-family:var(--yw-font-mono);font-size:12px;font-weight:500;
  letter-spacing:.07em;color:var(--yw-muted);white-space:nowrap;
}
.yw-table tbody th{font-weight:500;color:var(--yw-paper)}
.yw-table code,.yw-table .yw-mono{font-family:var(--yw-font-mono);font-size:13px;letter-spacing:.02em;color:var(--yw-electric)}

/* 纸感分区 */
.yw-paper{background:var(--yw-paper);color:var(--yw-ink)}
.yw-paper-2{background:var(--yw-paper-2);color:var(--yw-ink)}
.yw-paper .yw-kicker,.yw-paper-2 .yw-kicker{color:var(--yw-signal-deep)}
.yw-paper .yw-lead,.yw-paper-2 .yw-lead{color:var(--yw-paper-muted)}
.yw-paper .yw-num,.yw-paper-2 .yw-num{color:rgba(10,12,15,.06);-webkit-text-stroke:1px #C7BFAD}
.yw-paper .yw-table th,.yw-paper .yw-table td{border-color:var(--yw-paper-line)}
.yw-paper .yw-table thead th{color:var(--yw-paper-muted)}
.yw-paper .yw-table tbody th{color:var(--yw-ink)}
.yw-paper .yw-table code,.yw-paper .yw-mono{color:var(--yw-electric-deep)}
.yw-paper .yw-tag,.yw-paper-2 .yw-tag{border-color:#C7BFAD;color:var(--yw-paper-muted)}
.yw-paper .yw-tag--signal,.yw-paper-2 .yw-tag--signal{border-color:var(--yw-signal-deep);color:var(--yw-signal-deep)}
.yw-paper .yw-tag--blue,.yw-paper-2 .yw-tag--blue{border-color:var(--yw-electric-deep);color:var(--yw-electric-deep)}

/* 长文 */
.yw-prose{max-width:68ch;font-size:16.5px;line-height:1.85}
.yw-prose p+p{margin-top:16px}
.yw-prose a{color:var(--yw-electric);text-decoration:underline;text-underline-offset:3px}
.yw-paper .yw-prose a,.yw-paper-2 .yw-prose a{color:var(--yw-electric-deep)}
.yw-prose ul{margin-top:14px;display:grid;gap:10px}
.yw-prose ul>li{position:relative;padding-left:20px}
.yw-prose ul>li::before{content:"";position:absolute;left:0;top:.75em;width:8px;height:2px;background:var(--yw-signal)}

/* 图片容器 */
.yw-frame{
  position:relative;overflow:hidden;margin:0;
  background:var(--yw-graphite-2);
  border:1px solid var(--yw-line);border-radius:var(--yw-radius);
}
.yw-frame>img,.yw-frame>.yw-frame__img{display:block;width:100%;height:100%;object-fit:cover}
.yw-frame--16x9{aspect-ratio:16/9}
.yw-frame--4x3{aspect-ratio:4/3}
.yw-frame--21x9{aspect-ratio:21/9}
.yw-frame--1x1{aspect-ratio:1/1}
.yw-frame--paper{background:var(--yw-paper-2);border-color:var(--yw-paper-line)}
.yw-frame--scan::before{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:repeating-linear-gradient(0deg,rgba(241,237,228,.05) 0 1px,transparent 1px 7px);
}
.yw-frame__cap{
  margin-top:10px;
  font-family:var(--yw-font-mono);font-size:12px;letter-spacing:.05em;
  color:var(--yw-muted);line-height:1.6;
}
.yw-paper .yw-frame__cap,.yw-paper-2 .yw-frame__cap{color:var(--yw-paper-muted)}

/* ---------- 10. 显现与目录高亮 ---------- */
[data-reveal]{opacity:0;transform:translateY(14px);transition:opacity .45s ease,transform .45s ease}
[data-reveal].is-in{opacity:1;transform:none}
[data-toc-link]{transition:color .18s ease,border-color .18s ease}
[data-toc-link].is-active{color:var(--yw-signal)}

/* ---------- 11. 页脚 ---------- */
.yw-footer{background:var(--yw-ink);color:var(--yw-paper)}
.yw-footer__inner{
  display:grid;
  grid-template-columns:minmax(220px,1.5fr) minmax(0,2.4fr) minmax(240px,1.6fr);
  gap:clamp(28px,4vw,64px);
  padding-block:clamp(46px,6vw,84px) clamp(34px,4vw,56px);
}
.yw-footer__mark{font-size:24px;font-weight:900;letter-spacing:-.02em;line-height:1.2}
.yw-footer__sub{font-family:var(--yw-font-mono);font-size:11.5px;letter-spacing:.1em;color:var(--yw-signal);margin-top:6px}
.yw-footer__desc{font-size:14px;line-height:1.8;color:var(--yw-muted);margin-top:16px;max-width:34ch}
.yw-footer__stamp{
  margin-top:18px;font-family:var(--yw-font-mono);font-size:12px;letter-spacing:.05em;
  color:var(--yw-paper);border-left:2px solid var(--yw-electric);padding-left:10px;
}
.yw-footer__nav{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:clamp(18px,2.4vw,36px)}
.yw-footer__ttl{
  font-family:var(--yw-font-mono);font-size:12px;font-weight:500;letter-spacing:.1em;
  color:var(--yw-paper);margin:0 0 16px;padding-bottom:10px;
  border-bottom:1px solid var(--yw-line);
}
.yw-footer__list{display:grid;gap:11px}
.yw-footer__list a{font-size:14px;color:var(--yw-muted);transition:color .18s ease}
.yw-footer__list a:hover{color:var(--yw-electric)}
.yw-footer__contactList{display:grid;gap:12px}
.yw-footer__contactList li{
  display:grid;grid-template-columns:48px minmax(0,1fr);gap:10px;align-items:baseline;
  font-size:14px;line-height:1.6;color:var(--yw-muted);
}
.yw-footer__contactList a{color:var(--yw-paper);transition:color .18s ease}
.yw-footer__contactList a:hover{color:var(--yw-electric)}
.yw-footer__k{font-family:var(--yw-font-mono);font-size:11px;letter-spacing:.08em;color:var(--yw-signal)}
.yw-footer__note{font-size:13px;line-height:1.75;color:var(--yw-muted);margin-top:18px}
.yw-footer__contact .yw-btn{margin-top:20px}
.yw-footer__base{border-top:1px solid var(--yw-line);background:var(--yw-graphite)}
.yw-footer__baseInner{
  display:flex;flex-wrap:wrap;gap:10px 28px;align-items:baseline;justify-content:space-between;
  padding-block:20px;
}
.yw-footer__legal{font-family:var(--yw-font-mono);font-size:12px;letter-spacing:.04em;color:var(--yw-muted)}
.yw-footer__legal--note{max-width:58ch}

/* ---------- 12. 焦点可见 ---------- */
:where(a,button,input,select,textarea,summary,[tabindex]):focus-visible{
  outline:2px solid var(--yw-electric);
  outline-offset:2px;
  border-radius:var(--yw-radius);
}
.yw-skip:focus-visible{outline-color:var(--yw-paper)}

/* ---------- 13. 响应式 ---------- */
@media (max-width:1240px){
  .yw-header__note{display:none}
}
@media (max-width:1040px){
  :root{--yw-header-h:110px}
  .yw-header__inner{min-height:70px}
  .yw-header__metaInner{min-height:38px}
  .yw-header__phone{display:none}
  .yw-navtoggle{display:inline-flex}
  .yw-nav{
    position:absolute;left:0;right:0;top:100%;margin:0;
    background:var(--yw-graphite-2);
    border-top:1px solid var(--yw-line);
    border-bottom:1px solid var(--yw-line);
    box-shadow:0 26px 52px rgba(0,0,0,.5);
    opacity:0;visibility:hidden;transform:translateY(-10px);
    transition:opacity .22s ease,transform .22s ease,visibility .22s;
    max-height:calc(100vh - var(--yw-header-h));
    overflow-y:auto;overscroll-behavior:contain;
  }
  .yw-header[data-open] .yw-nav{opacity:1;visibility:visible;transform:none}
  .yw-nav__list{flex-direction:column;align-items:stretch;gap:0;padding:10px var(--yw-gutter) 22px}
  .yw-nav__link{padding:15px 0;font-size:16.5px;opacity:.88;border-bottom:1px solid rgba(57,66,77,.55)}
  .yw-nav__link[aria-current="page"]{color:var(--yw-signal)}
  .yw-nav__link[aria-current="page"]::after{left:0;right:auto;bottom:-1px;width:38px}
  .yw-grid--4-8,.yw-grid--5-7,.yw-grid--7-5{grid-template-columns:1fr}
  .yw-grid--3{grid-template-columns:repeat(2,minmax(0,1fr))}
  .yw-footer__inner{grid-template-columns:1fr 1fr}
  .yw-footer__contact{grid-column:1 / -1}
}
@media (max-width:760px){
  :root{--yw-header-h:98px}
  .yw-header__inner{min-height:62px}
  .yw-header__tagline{font-size:11px;letter-spacing:.02em}
  .yw-header__tagline::before,.yw-header__tagline::after{content:""}
  .yw-grid--2,.yw-grid--3{grid-template-columns:1fr}
  .yw-footer__inner{grid-template-columns:1fr;gap:34px}
  .yw-footer__nav{grid-template-columns:1fr 1fr}
  .yw-btn{width:auto}
  .yw-table th,.yw-table td{padding:9px 10px}
}
@media (max-width:460px){
  .yw-footer__nav{grid-template-columns:1fr}
  .yw-header__cta{display:none}
}

/* ---------- 14. 减弱动效 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.01ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.01ms !important;
  }
  [data-reveal]{opacity:1 !important;transform:none !important}
}