/* ==========================================================================
   贝博中文站 · 共享样式 /assets/site.css
   深海蓝 · 贝母白 · 青海湖青 · 沙金
   ========================================================================== */

/* 1. 变量 */
:root{
  --ink:#0B2A3F;
  --ink-2:#123C56;
  --ink-3:#16465F;
  --pearl:#F6F4EF;
  --pearl-2:#FCFBF8;
  --lake:#2E8C8C;
  --lake-2:#A8D3D0;
  --gold:#C9A227;
  --gold-2:#E7D59A;
  --graphite:#24313A;
  --mist:#546E7E;
  --line:#D8D2C6;
  --line-dark:rgba(168,211,208,.22);
  --shell-w:1320px;
  --pad:clamp(18px,4vw,56px);
  --radius:3px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --shadow-1:0 1px 0 rgba(11,42,63,.05),0 18px 40px -30px rgba(11,42,63,.55);
  --font-sans:"Noto Sans SC","Source Han Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono","Roboto Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}

/* 2. Reset */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
body,h1,h2,h3,h4,h5,h6,p,figure,blockquote,dl,dd,ul,ol{margin:0}
ul,ol{padding:0;list-style:none}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;cursor:pointer}
img,picture,svg,video{display:block;max-width:100%}
table{width:100%;border-collapse:collapse}
hr{border:0}

/* 3. 基础排版 */
body{
  font-family:var(--font-sans);
  font-size:16px;
  font-weight:400;
  line-height:1.75;
  letter-spacing:.01em;
  color:var(--graphite);
  background:var(--pearl);
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
h1,h2,h3,h4{font-weight:800;line-height:1.2;letter-spacing:-.015em;color:var(--ink)}
h1{font-size:clamp(2.6rem,6vw,5.4rem);font-weight:900;line-height:1.05;letter-spacing:-.02em}
h2{font-size:clamp(1.55rem,2.6vw,2rem)}
h3{font-size:clamp(1.15rem,1.6vw,1.4rem);font-weight:700}
p{margin:0}
strong,b{font-weight:700}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:.02em}
::selection{background:var(--lake);color:#fff}

:focus-visible{outline:2px solid var(--lake);outline-offset:3px;border-radius:2px}
.site-header :focus-visible,.site-footer :focus-visible{outline-color:var(--gold-2)}

#main-content{display:block;scroll-margin-top:96px}

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

.skip-link{
  position:absolute;left:12px;top:-72px;z-index:200;
  padding:12px 20px;background:var(--gold);color:#231A04;
  font-size:14px;font-weight:700;letter-spacing:.04em;border-radius:var(--radius);
  transition:top .22s var(--ease);
}
.skip-link:focus{top:12px}

/* 4. 布局容器 */
.shell{width:100%;max-width:var(--shell-w);margin-inline:auto;padding-inline:var(--pad)}
.section{padding-block:clamp(48px,7vw,104px)}
.section--pearl{background:var(--pearl)}
.section--pearl-2{background:var(--pearl-2)}
.section--ink{background:var(--ink);color:rgba(246,244,239,.85)}
.section--ink h1,.section--ink h2,.section--ink h3,.section--ink h4{color:var(--pearl)}
.section--ink .separator,.section--ink .rule{background:var(--line-dark)}
.stack{display:grid;gap:clamp(16px,2.2vw,28px)}

.grid{display:grid;gap:clamp(20px,3vw,40px)}
.grid--7-5{grid-template-columns:7fr 5fr}
.grid--5-7{grid-template-columns:5fr 7fr}
.grid--4-8{grid-template-columns:4fr 8fr}
.grid--8-4{grid-template-columns:8fr 4fr}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--auto{grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}

.section-head{display:grid;gap:14px;max-width:64ch;margin-bottom:clamp(24px,4vw,44px)}
.section-title{font-size:clamp(1.55rem,2.6vw,2rem);font-weight:800;letter-spacing:-.015em;color:var(--ink)}
.section--ink .section-title{color:var(--pearl)}
.section-note{font-size:15.5px;line-height:1.8;color:var(--mist)}
.section--ink .section-note{color:rgba(246,244,239,.72)}
.eyebrow{
  display:inline-flex;align-items:center;gap:10px;
  font-family:var(--font-mono);font-size:12px;font-weight:500;
  letter-spacing:.2em;color:var(--lake);text-transform:uppercase;
}
.eyebrow::before{content:"";width:26px;height:1px;background:currentColor;opacity:.75}
.section--ink .eyebrow{color:var(--lake-2)}
.lede{font-size:clamp(1.02rem,1.4vw,1.2rem);line-height:1.85;color:var(--mist)}
.section--ink .lede{color:rgba(246,244,239,.78)}
.rule{display:block;height:1px;width:100%;background:var(--line)}

.num{font-family:var(--font-mono);font-size:12px;letter-spacing:.16em;color:var(--lake)}

.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 11px;border:1px solid var(--line);border-radius:999px;
  font-size:12.5px;letter-spacing:.06em;color:var(--ink-2);background:var(--pearl-2);
}
.tag--lake{border-color:rgba(46,140,140,.42);color:#1F6666;background:rgba(168,211,208,.2)}
.tag--gold{border-color:rgba(201,162,39,.46);color:#8A6E12;background:rgba(231,213,154,.22)}
.tag-row{display:flex;flex-wrap:wrap;gap:8px}

.crumbs{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)}
.crumbs li{display:inline-flex;align-items:center;gap:8px}
.crumbs li+li::before{content:"/";color:var(--line)}
.crumbs a{transition:color .2s var(--ease)}
.crumbs a:hover{color:var(--lake)}
.crumbs [aria-current="page"]{color:var(--ink);font-weight:500}

/* 5. 按钮 */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:11px 20px;border:1px solid transparent;border-radius:var(--radius);
  font-size:14px;font-weight:600;letter-spacing:.05em;cursor:pointer;
  transition:background .22s var(--ease),color .22s var(--ease),border-color .22s var(--ease),transform .22s var(--ease);
}
.btn:hover{transform:translateY(-1px)}
.btn:active{transform:translateY(0)}
.btn-gold{background:var(--gold);border-color:var(--gold);color:#231A04}
.btn-gold:hover{background:var(--gold-2);border-color:var(--gold-2);color:#231A04}
.btn-lake{background:var(--lake);border-color:var(--lake);color:#fff}
.btn-lake:hover{background:#267878;border-color:#267878}
.btn-outline{background:transparent;border-color:var(--line);color:var(--ink)}
.btn-outline:hover{border-color:var(--lake);color:var(--lake)}
.section--ink .btn-outline,.site-footer .btn-outline{border-color:var(--line-dark);color:var(--pearl)}
.section--ink .btn-outline:hover,.site-footer .btn-outline:hover{border-color:var(--gold-2);color:var(--gold-2)}

/* 6. 图片容器基础规则（页面阶段在此放图片） */
.frame{
  position:relative;display:block;overflow:hidden;border-radius:var(--radius);
  background:linear-gradient(140deg,var(--ink) 0%,var(--ink-2) 56%,var(--ink-3) 100%);
  box-shadow:var(--shadow-1);
  isolation:isolate;
}
.frame::before{
  content:"";position:absolute;inset:0;z-index:0;pointer-events:none;
  background-image:
    linear-gradient(90deg,rgba(168,211,208,.15) 1px,transparent 1px),
    linear-gradient(0deg,rgba(168,211,208,.11) 1px,transparent 1px);
  background-size:48px 48px,48px 48px;
}
.frame::after{
  content:"";position:absolute;inset:0;z-index:0;pointer-events:none;
  background:radial-gradient(120% 90% at 12% 6%,rgba(46,140,140,.45),transparent 62%);
}
.frame>img,.frame>picture,.frame>video{position:relative;z-index:1;width:100%;height:100%;object-fit:cover}
.frame--21x9{aspect-ratio:21/9}
.frame--16x9{aspect-ratio:16/9}
.frame--4x3{aspect-ratio:4/3}
.frame--1x1{aspect-ratio:1/1}
.frame--3x4{aspect-ratio:3/4}
.frame-note{
  position:absolute;z-index:2;left:14px;bottom:12px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;color:var(--lake-2);
}

/* 7. 页头：命令栏 */
.site-header{
  position:sticky;top:0;z-index:80;
  background:var(--ink);color:var(--pearl);
  border-bottom:1px solid var(--line-dark);
}
.header-bar{
  display:grid;grid-template-columns:auto minmax(0,1fr) auto;
  align-items:center;gap:clamp(14px,2.4vw,40px);
  width:100%;max-width:var(--shell-w);margin-inline:auto;
  padding-inline:var(--pad);min-height:78px;
  transition:min-height .3s var(--ease);
}
.site-header[data-scrolled] .header-bar{min-height:60px}

.brand{display:inline-flex;align-items:center;gap:12px;color:var(--pearl);flex:0 0 auto}
.brand-mark{
  display:grid;place-items:center;width:40px;height:40px;flex:0 0 auto;
  font-family:var(--font-mono);font-size:13px;font-weight:700;letter-spacing:.04em;
  color:var(--ink);background:var(--lake-2);border-radius:2px;
  box-shadow:inset 0 0 0 1px rgba(11,42,63,.28);
  transition:width .3s var(--ease),height .3s var(--ease);
}
.site-header[data-scrolled] .brand-mark{width:34px;height:34px}
.brand-text{display:flex;flex-direction:column;line-height:1.15}
.brand-name{font-size:17px;font-weight:800;letter-spacing:.02em;color:var(--pearl)}
.brand-sub{font-family:var(--font-mono);font-size:10px;letter-spacing:.24em;color:var(--lake-2);transition:opacity .25s var(--ease)}
.site-header[data-scrolled] .brand-sub{opacity:0}

.nav-toggle{
  display:none;align-items:center;gap:9px;
  padding:9px 13px;border:1px solid rgba(168,211,208,.4);border-radius:2px;
  color:var(--pearl);font-size:12.5px;letter-spacing:.08em;
  transition:border-color .2s var(--ease),background .2s var(--ease);
}
.nav-toggle:hover{border-color:var(--gold-2);color:var(--gold-2)}
.nav-toggle-bars{position:relative;width:16px;height:10px;flex:0 0 auto}
.nav-toggle-bars::before,.nav-toggle-bars::after{
  content:"";position:absolute;left:0;width:16px;height:1.5px;background:currentColor;
  transition:transform .26s var(--ease);
}
.nav-toggle-bars::before{top:0}
.nav-toggle-bars::after{bottom:0}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before{transform:translateY(4.25px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after{transform:translateY(-4.25px) rotate(-45deg)}

.site-nav{min-width:0;position:static;display:block}
.nav-list{
  display:flex;align-items:center;gap:clamp(10px,1.6vw,26px);
  counter-reset:navidx;
}
.nav-list>li{counter-increment:navidx}
.nav-list a{
  position:relative;display:inline-flex;align-items:baseline;gap:6px;
  padding:6px 2px;font-size:14.5px;font-weight:500;white-space:nowrap;
  color:rgba(246,244,239,.82);transition:color .2s var(--ease);
}
.nav-list a::before{
  content:counter(navidx,decimal-leading-zero);
  font-family:var(--font-mono);font-size:10px;letter-spacing:.08em;
  color:var(--lake-2);opacity:.7;transition:color .2s var(--ease),opacity .2s var(--ease);
}
.nav-list a::after{
  content:"";position:absolute;left:0;right:0;bottom:0;height:2px;
  background:var(--lake);transform:scaleX(0);transform-origin:left;
  transition:transform .26s var(--ease);
}
.nav-list a:hover{color:var(--pearl)}
.nav-list a:hover::after{transform:scaleX(1)}
.nav-list a[aria-current="page"]{color:var(--pearl);font-weight:600}
.nav-list a[aria-current="page"]::before{color:var(--gold);opacity:1}
.nav-list a[aria-current="page"]::after{transform:scaleX(1);background:var(--lake)}

.header-status{display:flex;align-items:center;gap:clamp(10px,1.4vw,20px);flex:0 0 auto}
.status-item{display:inline-flex;align-items:center;gap:7px;font-size:11.5px;letter-spacing:.06em;white-space:nowrap}
.status-key{color:var(--lake-2)}
.status-val{font-family:var(--font-mono);font-size:12px;letter-spacing:.02em;color:var(--gold-2)}
.status-dot{
  width:7px;height:7px;border-radius:50%;background:var(--lake);flex:0 0 auto;
  animation:breathe 2.4s ease-in-out infinite;
}
@keyframes breathe{
  0%,100%{opacity:.5;transform:scale(.85)}
  50%{opacity:1;transform:scale(1.15)}
}

.scroll-progress{
  position:absolute;left:0;bottom:-1px;width:100%;height:2px;
  background:linear-gradient(90deg,var(--lake),var(--gold));
  transform:scaleX(var(--progress,0));transform-origin:left;
  transition:transform .12s linear;
}

/* 8. 页脚 */
.site-footer{
  position:relative;
  background:var(--ink);color:rgba(246,244,239,.78);
  border-top:1px solid var(--line-dark);
}
.site-footer::before{
  content:"";position:absolute;top:0;left:0;height:3px;width:min(34vw,360px);
  background:linear-gradient(90deg,var(--lake),var(--gold));
}
.footer-grid{
  display:grid;grid-template-columns:1.5fr 1fr 1fr 1.3fr;
  gap:clamp(24px,3vw,56px);
  padding-block:clamp(42px,6vw,72px) clamp(30px,4vw,52px);
}
.footer-col{min-width:0}
.footer-col-title{
  font-size:12px;font-weight:600;line-height:1.4;letter-spacing:.18em;
  color:var(--lake-2);margin-bottom:16px;
}
.footer-logo{display:inline-flex;align-items:center;gap:12px;color:var(--pearl)}
.brand-mark--footer{
  width:38px;height:38px;color:var(--ink);background:var(--lake-2);
  box-shadow:inset 0 0 0 1px rgba(11,42,63,.3);
}
.footer-logo-text{display:flex;flex-direction:column;line-height:1.2}
.footer-name{font-size:18px;font-weight:800;letter-spacing:.02em;color:var(--pearl)}
.footer-sub{font-family:var(--font-mono);font-size:10px;letter-spacing:.18em;color:var(--lake-2)}
.footer-tagline{margin-top:16px;max-width:34ch;font-size:14px;line-height:1.8;color:rgba(246,244,239,.72)}
.footer-stamp{margin-top:18px;font-size:11.5px;letter-spacing:.2em;color:var(--lake-2)}

.footer-links li+li{margin-top:10px}
.footer-links a{display:inline-block;font-size:14.5px;color:rgba(246,244,239,.76);transition:color .2s var(--ease)}
.footer-links a::after{content:"";display:block;height:1px;width:0;background:var(--gold);transition:width .25s var(--ease)}
.footer-links a:hover{color:var(--pearl)}
.footer-links a:hover::after{width:100%}

.footer-facts{display:grid;gap:11px}
.fact{
  display:flex;align-items:baseline;justify-content:space-between;gap:14px;
  padding-bottom:10px;border-bottom:1px dashed rgba(168,211,208,.2);
  font-size:13.5px;
}
.fact:last-child{border-bottom:0;padding-bottom:0}
.fact-key{color:rgba(246,244,239,.66)}
.fact-val{font-family:var(--font-mono);font-size:12.5px;letter-spacing:.02em;color:var(--gold-2)}

.contact-list{display:grid;gap:14px}
.contact-item{
  display:grid;grid-template-columns:minmax(0,1fr) auto;gap:3px 10px;align-items:center;
  padding-bottom:12px;border-bottom:1px solid rgba(168,211,208,.14);
}
.contact-item:last-child{border-bottom:0;padding-bottom:0}
.contact-item--stack{grid-template-columns:minmax(0,1fr)}
.contact-key{grid-column:1/-1;font-size:11.5px;letter-spacing:.14em;color:var(--lake-2)}
.contact-val{font-size:13.5px;color:var(--pearl);word-break:break-all}
.contact-item--stack .contact-val{grid-column:1/-1;font-size:13.5px;line-height:1.6;color:rgba(246,244,239,.8)}
.copy-btn{
  justify-self:end;padding:4px 10px;border:1px solid rgba(168,211,208,.32);border-radius:2px;
  font-size:11.5px;letter-spacing:.08em;color:var(--lake-2);
  transition:border-color .2s var(--ease),color .2s var(--ease),background .2s var(--ease);
}
.copy-btn:hover{border-color:var(--gold);color:var(--gold-2)}
.copy-btn.is-copied{border-color:var(--gold);background:var(--gold);color:#231A04}
.contact-note{margin-top:16px;font-size:12.5px;line-height:1.75;color:rgba(246,244,239,.6)}

.footer-legal{
  display:flex;flex-wrap:wrap;align-items:center;gap:10px 24px;
  padding-block:20px;border-top:1px solid rgba(168,211,208,.16);
  font-size:12.5px;color:rgba(246,244,239,.6);
}
.legal-copy{margin:0}
.legal-links{display:flex;flex-wrap:wrap;gap:18px}
.legal-links a{color:rgba(246,244,239,.7);transition:color .2s var(--ease)}
.legal-links a:hover{color:var(--pearl)}
.legal-icp{margin-left:auto;font-size:12px;letter-spacing:.06em;color:rgba(246,244,239,.5)}

/* 9. 显现动效 */
[data-reveal]{
  opacity:0;transform:translateY(14px);
  transition:opacity .52s var(--ease),transform .52s var(--ease);
  will-change:opacity,transform;
}
[data-reveal].is-revealed{opacity:1;transform:none}

/* 10. 响应式 */
@media (max-width:1240px){
  .status-key{display:none}
}
@media (max-width:1080px){
  .header-bar{
    display:flex;flex-wrap:wrap;align-items:center;
    gap:10px;min-height:64px;position:relative;
  }
  .site-header[data-scrolled] .header-bar{min-height:58px}
  .brand{order:1}
  .header-status{order:2;margin-left:auto;gap:10px}
  .nav-toggle{order:3;display:inline-flex}
  .site-nav{
    order:4;flex:1 0 100%;
    position:absolute;top:100%;left:0;right:0;display:none;
    background:var(--ink-2);border-top:1px solid var(--line-dark);
    box-shadow:0 26px 44px -30px rgba(0,0,0,.85);
    max-height:min(74vh,600px);overflow-y:auto;
  }
  .site-nav[data-open]{display:block;animation:panelIn .26s var(--ease)}
  .nav-list{flex-direction:column;align-items:stretch;gap:0;padding:8px var(--pad) 18px}
  .nav-list>li{border-bottom:1px solid rgba(168,211,208,.14)}
  .nav-list>li:last-child{border-bottom:0}
  .nav-list a{padding:15px 4px;font-size:16px;width:100%}
  .nav-list a::before{font-size:11px}
  .nav-list a::after{left:4px;right:auto;bottom:9px;width:24px}
  .grid--7-5,.grid--5-7,.grid--4-8,.grid--8-4,.grid--3{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@keyframes panelIn{
  from{opacity:0;transform:translateY(-8px)}
  to{opacity:1;transform:none}
}
@media (max-width:900px){
  .status-item--round{display:none}
  .frame--21x9{aspect-ratio:16/9}
}
@media (max-width:640px){
  .brand-sub{display:none}
  .footer-grid{grid-template-columns:1fr}
  .legal-icp{margin-left:0;width:100%}
  .frame--3x4{aspect-ratio:4/5}
  .btn{padding:10px 16px;font-size:13.5px}
}

/* 11. 动效偏好 */
@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
  [data-reveal]{opacity:1 !important;transform:none !important}
  .scroll-progress{transition:none !important}
}
@media (prefers-reduced-motion: no-preference){
  html{scroll-behavior:smooth}
}