/* ==========================================================================
   博亚 BY · 共享样式表  /assets/site.css
   深空蓝黑底 + 电光青 / 暖橙双强调 · 框架式导航 · 玻璃层与实色层并置
   ========================================================================== */

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

/* --- 2. 变量 ------------------------------------------------------------- */
:root{
  --ink:#0A0F1A;
  --ink-deep:#070B13;
  --panel:#111A2B;
  --paper:#F3EDE2;
  --mist:#8B98AB;
  --cyan:#1BE0D4;
  --cyan-deep:#0B9E96;
  --orange:#FF8A3D;
  --brick:#D9562B;
  --green:#3DD68C;
  --glass:rgba(255,255,255,.07);
  --glass-strong:rgba(255,255,255,.13);
  --line:rgba(243,237,226,.14);
  --line-soft:rgba(243,237,226,.08);
  --rail:132px;
  --bar:64px;
  --gutter:clamp(20px,5vw,64px);
  --maxw:1180px;
  --serif:"Noto Serif SC","Source Han Serif SC","Songti SC",Georgia,serif;
  --sans:"Inter","Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --mono:"JetBrains Mono","SFMono-Regular",Consolas,"Liberation Mono",monospace;
  --ease:cubic-bezier(.22,.61,.36,1);
}

/* --- 3. 中文排版与基础 ------------------------------------------------- */
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
@media (prefers-reduced-motion:no-preference){html{scroll-behavior:smooth}}
body{
  background:var(--ink);
  color:var(--paper);
  font-family:var(--sans);
  font-size:16px;
  line-height:1.75;
  letter-spacing:.01em;
  min-height:100vh;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
@media (min-width:960px){body{padding-left:var(--rail)}}

h1,h2,h3,h4{font-family:var(--serif);font-weight:800;line-height:1.2;letter-spacing:-.01em}
h1{font-size:clamp(34px,7vw,64px)}
h2{font-size:clamp(24px,4vw,40px)}
h3{font-size:clamp(19px,2.4vw,24px)}
strong,b{font-weight:700}
em,i{font-style:normal}

::selection{background:var(--cyan);color:#04211F}

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

#main-content{display:block;padding-top:var(--bar);scroll-margin-top:calc(var(--bar) + 12px)}

/* --- 4. 版面容器 ------------------------------------------------------- */
.container{width:100%;max-width:var(--maxw);margin-inline:auto;padding-inline:var(--gutter)}
.container-narrow{max-width:760px}
.section{padding-block:clamp(48px,7vw,96px)}
.section-tight{padding-block:clamp(28px,4vw,56px)}

.eyebrow{
  display:inline-flex;align-items:center;gap:10px;
  font-family:var(--mono);font-size:11px;font-weight:500;
  letter-spacing:.22em;text-transform:uppercase;
  color:var(--orange);margin-bottom:14px;
}
.eyebrow::before{content:"";width:26px;height:1px;background:currentColor;opacity:.75}
.section-title{font-size:clamp(24px,4vw,40px);font-weight:800}
.section-desc{margin-top:14px;max-width:38em;color:var(--mist);font-size:15px;line-height:1.85}
.lead{font-size:clamp(15px,1.6vw,17px);line-height:1.9;color:rgba(243,237,226,.82);max-width:38em}

.prose{max-width:38em;font-size:16px;line-height:1.9;color:rgba(243,237,226,.82)}
.prose p+p{margin-top:1em}
.prose h2,.prose h3{margin-top:1.8em;margin-bottom:.6em;color:var(--paper)}
.prose ul,.prose ol{margin:1em 0;padding-left:1.15em;list-style:disc}
.prose ol{list-style:decimal}
.prose li+li{margin-top:.4em}
.prose a{color:var(--cyan);border-bottom:1px solid rgba(27,224,212,.42);transition:border-color .2s var(--ease),color .2s var(--ease)}
.prose a:hover{border-bottom-color:var(--cyan)}
.prose code{font-family:var(--mono);font-size:.9em;color:var(--orange);background:rgba(255,138,61,.09);padding:1px 6px;border-radius:2px}

/* --- 5. 表面层：实色面板 / 玻璃层 --------------------------------------- */
.panel{
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:3px;
  padding:clamp(18px,3vw,28px);
}
.glass{
  background:var(--glass);
  border:1px solid var(--glass-strong);
  border-radius:3px;
  -webkit-backdrop-filter:blur(12px);
  backdrop-filter:blur(12px);
  padding:clamp(14px,2.4vw,22px);
}

/* --- 6. 标签 ----------------------------------------------------------- */
.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 10px;border-radius:2px;
  font-family:var(--mono);font-size:11px;font-weight:500;letter-spacing:.08em;
  border:1px solid transparent;white-space:nowrap;
}
.tag-version{color:var(--orange);border-color:rgba(255,138,61,.42);background:rgba(255,138,61,.09)}
.tag-status{color:var(--green);border-color:rgba(61,214,140,.38);background:rgba(61,214,140,.09)}
.tag-muted{color:var(--mist);border-color:var(--line);background:rgba(255,255,255,.03)}

/* --- 7. 按钮 ----------------------------------------------------------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:11px 20px;border-radius:2px;
  font-family:var(--sans);font-size:13px;font-weight:600;letter-spacing:.06em;
  border:1px solid transparent;cursor:pointer;
  transition:background .2s var(--ease),color .2s var(--ease),
             border-color .2s var(--ease),box-shadow .2s var(--ease);
}
.btn-solid{background:var(--cyan);color:#04211F;border-color:var(--cyan)}
.btn-solid:hover{box-shadow:0 0 0 4px rgba(27,224,212,.2)}
.btn-solid:active{background:var(--cyan-deep);border-color:var(--cyan-deep);color:var(--paper);box-shadow:none}
.btn-quiet{color:var(--cyan);border-color:rgba(27,224,212,.48);background:rgba(27,224,212,.06)}
.btn-quiet:hover{background:rgba(27,224,212,.15);border-color:var(--cyan);box-shadow:0 0 0 3px rgba(27,224,212,.12)}
.btn-quiet:active{background:rgba(11,158,150,.28);color:var(--paper)}
.btn-line{color:var(--paper);border-color:var(--line);background:rgba(255,255,255,.02)}
.btn-line:hover{border-color:var(--mist);background:var(--glass)}

/* --- 8. 图片容器 ------------------------------------------------------- */
.figure{
  position:relative;display:block;overflow:hidden;margin:0;border-radius:3px;
  background:linear-gradient(150deg,#131D30 0%,#0C1421 58%,#0A0F1A 100%);
  border:1px solid var(--line);
}
.figure>img,
.figure>svg{width:100%;height:100%;object-fit:cover;object-position:center}
.figure::after{content:"";position:absolute;inset:0;border:1px solid rgba(255,255,255,.06);pointer-events:none}
.figure>figcaption{
  position:absolute;left:0;right:0;bottom:0;
  padding:10px 14px;
  font-family:var(--mono);font-size:11px;letter-spacing:.06em;color:var(--paper);
  background:linear-gradient(0deg,rgba(7,11,19,.9),rgba(7,11,19,0));
}
.figure-ultra{aspect-ratio:21/9}
.figure-wide{aspect-ratio:16/9}
.figure-square{aspect-ratio:1/1}
.figure-tall{aspect-ratio:3/4}
.figure-soft{background:var(--glass);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-color:var(--glass-strong)}

/* --- 9. 面包屑 --------------------------------------------------------- */
.breadcrumb{margin-bottom:clamp(18px,3vw,28px)}
.breadcrumb ol{display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  font-family:var(--mono);font-size:11px;letter-spacing:.09em;color:var(--mist)}
.breadcrumb a{color:var(--mist);transition:color .2s var(--ease)}
.breadcrumb a:hover{color:var(--cyan)}
.breadcrumb li:not(:last-child)::after{content:"/";margin-left:8px;color:#39445A}
.breadcrumb li[aria-current="page"]{color:rgba(243,237,226,.75)}

/* --- 10. 可展开内容组 -------------------------------------------------- */
.fold{
  border:1px solid var(--line);border-radius:3px;
  background:rgba(255,255,255,.02);
  transition:border-color .2s var(--ease),background .2s var(--ease);
}
.fold[data-open]{border-color:rgba(27,224,212,.34);background:rgba(27,224,212,.035)}
.fold-head{
  display:flex;align-items:flex-start;gap:14px;width:100%;
  padding:16px 18px;text-align:left;
  font-family:var(--serif);font-size:clamp(16px,2vw,19px);font-weight:700;
  line-height:1.55;color:var(--paper);
  transition:color .2s var(--ease);
}
.fold-head:hover{color:var(--cyan)}
.fold-head::after{
  content:"";flex:0 0 auto;width:9px;height:9px;margin-left:auto;margin-top:8px;
  border-right:1.5px solid currentColor;border-bottom:1.5px solid currentColor;
  transform:rotate(45deg);
  transition:transform .25s var(--ease);
}
.fold[data-open] .fold-head::after{transform:rotate(-135deg)}
.fold-body{display:grid;grid-template-rows:0fr;transition:grid-template-rows .3s var(--ease)}
.fold[data-open] .fold-body{grid-template-rows:1fr}
.fold-inner{overflow:hidden}
.fold-content{padding:0 18px 20px;max-width:44em;font-size:15px;line-height:1.85;color:rgba(243,237,226,.8)}

/* --- 11. 滚动显现 ------------------------------------------------------ */
.reveal-init{
  opacity:0;transform:translateY(16px);
  transition:opacity .5s var(--ease),transform .5s var(--ease);
}
.reveal-init.is-in{opacity:1;transform:none}

/* --- 12. 跳过链接 ------------------------------------------------------ */
.skip-link{
  position:fixed;left:10px;top:10px;z-index:200;
  transform:translateY(-180%);
  padding:10px 18px;border-radius:2px;
  background:var(--cyan);color:#04211F;
  font-size:13px;font-weight:600;letter-spacing:.04em;
  transition:transform .2s var(--ease);
}
.skip-link:focus{transform:translateY(0)}

/* --- 13. 头部 ---------------------------------------------------------- */
.site-header{position:relative}

.header-bar{
  position:fixed;top:0;left:0;right:0;
  height:var(--bar);z-index:70;
  display:flex;align-items:center;justify-content:space-between;gap:12px;
  padding-inline:clamp(16px,4vw,28px);
  background:rgba(10,15,26,.88);
  -webkit-backdrop-filter:blur(14px);
  backdrop-filter:blur(14px);
  border-bottom:1px solid var(--line);
}
@media (min-width:960px){
  .header-bar{left:var(--rail);padding-inline:clamp(24px,3vw,44px)}
}

.header-progress{
  position:absolute;left:0;right:0;bottom:-1px;height:2px;
  transform:scaleX(0);transform-origin:left center;
  background:linear-gradient(90deg,var(--cyan) 0%,var(--cyan-deep) 45%,var(--orange) 100%);
  opacity:.85;pointer-events:none;
  will-change:transform;
}

/* 品牌标识 */
.brand{display:inline-flex;align-items:center;gap:10px;min-width:0}
.brand-mark{
  display:grid;place-items:center;flex:0 0 auto;
  width:34px;height:34px;border-radius:2px;
  border:1px solid var(--cyan-deep);
  background:linear-gradient(140deg,rgba(27,224,212,.18),rgba(27,224,212,0));
  color:var(--cyan);font-family:var(--mono);font-size:12px;font-weight:500;letter-spacing:.04em;
}
.brand-lockup{display:flex;flex-direction:column;line-height:1.18;min-width:0}
.brand-name{font-family:var(--serif);font-size:17px;font-weight:800;letter-spacing:.02em;color:var(--paper)}
.brand-line{font-size:10.5px;letter-spacing:.16em;color:var(--mist);white-space:nowrap}

.header-tools{display:flex;align-items:center;gap:10px;flex:0 0 auto}

/* 目录按钮 */
.nav-toggle{
  display:inline-flex;align-items:center;gap:8px;
  padding:9px 12px;border-radius:2px;
  border:1px solid var(--line);
  font-size:12px;letter-spacing:.14em;color:var(--paper);
  transition:border-color .2s var(--ease),color .2s var(--ease),background .2s var(--ease);
}
.nav-toggle:hover{border-color:var(--cyan-deep);color:var(--cyan);background:rgba(27,224,212,.06)}
.nav-toggle-icon{display:block;width:16px}
.nav-toggle-icon i{
  display:block;height:1.5px;margin:4px 0;background:currentColor;
  transition:transform .25s var(--ease),opacity .2s var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle-icon i:first-child{transform:translateY(2.75px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle-icon i:last-child{transform:translateY(-2.75px) rotate(-45deg)}

/* 导航本体：移动端为顶部抽屉 */
.site-nav{
  position:fixed;top:var(--bar);left:0;right:0;z-index:65;
  max-height:0;overflow:hidden;
  background:rgba(7,11,19,.97);
  -webkit-backdrop-filter:blur(16px);
  backdrop-filter:blur(16px);
  border-bottom:1px solid var(--line);
  transition:max-height .36s var(--ease);
}
.site-nav[data-open]{max-height:calc(100vh - var(--bar));overflow-y:auto}

.nav-list{display:flex;flex-direction:column;padding:8px 0 4px;counter-reset:nav}
.nav-list li{display:block}
.nav-list a{
  display:flex;align-items:baseline;gap:12px;
  padding:14px clamp(16px,4vw,28px);
  border-left:2px solid transparent;
  font-size:15px;letter-spacing:.02em;color:var(--paper);
  transition:color .2s var(--ease),background .2s var(--ease),border-color .2s var(--ease);
}
.nav-list a::before{
  counter-increment:nav;
  content:counter(nav,decimal-leading-zero);
  font-family:var(--mono);font-size:11px;color:var(--mist);
}
.nav-list a:hover{color:var(--cyan);background:var(--glass)}
.nav-list a[aria-current="page"]{
  color:var(--cyan);
  border-left-color:var(--cyan);
  background:linear-gradient(90deg,rgba(27,224,212,.16),rgba(27,224,212,0));
}
.nav-list a[aria-current="page"]::before{color:var(--orange)}

.nav-note{
  margin:14px clamp(16px,4vw,28px) 14px;
  padding-top:14px;border-top:1px solid var(--line-soft);
  font-family:var(--mono);font-size:10.5px;line-height:1.7;letter-spacing:.08em;color:var(--mist);
}

/* 移动端收起时不可聚焦 */
@media (max-width:959px){
  .site-nav:not([data-open]) .nav-list a,
  .site-nav:not([data-open]) .nav-note{visibility:hidden}
  .site-nav[data-open] .nav-list a,
  .site-nav[data-open] .nav-note{visibility:visible}
}

/* 桌面端：左缘竖向导航脊 */
@media (min-width:960px){
  .nav-toggle{display:none}
  .site-nav{
    top:0;bottom:0;left:0;right:auto;
    width:var(--rail);
    max-height:none;overflow:visible;
    display:flex;flex-direction:column;
    padding:78px 0 26px;
    border-right:1px solid var(--line);border-bottom:0;
    background:linear-gradient(180deg,#0C1322 0%,#090E19 100%);
  }
  .nav-list{padding:0}
  .nav-list a{padding:13px 16px;font-size:13.5px;gap:9px}
  .nav-list a::before{font-size:10px}
  .nav-note{margin:auto 16px 0;padding-top:16px}
}

/* --- 14. 页脚 ---------------------------------------------------------- */
.site-footer{
  position:relative;
  margin-top:clamp(64px,10vw,128px);
  padding:clamp(40px,6vw,72px) 0 clamp(26px,4vw,40px);
  background:var(--ink-deep);
  border-top:1px solid var(--line);
}
.site-footer::before{
  content:"";position:absolute;top:-1px;left:0;
  width:min(200px,42%);height:2px;
  background:linear-gradient(90deg,var(--orange),var(--brick) 55%,rgba(217,86,43,0));
}
.footer-inner{width:100%;max-width:var(--maxw);margin-inline:auto;padding-inline:var(--gutter)}

.footer-head{
  display:flex;flex-wrap:wrap;align-items:baseline;gap:10px 20px;
  padding-bottom:clamp(24px,4vw,40px);
  border-bottom:1px solid var(--line);
}
.footer-brand{
  font-family:var(--serif);font-size:clamp(22px,3.2vw,30px);font-weight:800;
  letter-spacing:-.01em;color:var(--paper);
}
.footer-brand i{
  margin-left:8px;vertical-align:middle;
  font-family:var(--mono);font-size:.55em;letter-spacing:.1em;color:var(--orange);
}
.footer-tag{font-size:11.5px;letter-spacing:.2em;color:var(--mist)}

.footer-grid{
  display:grid;grid-template-columns:1fr;gap:clamp(26px,4vw,40px);
  padding:clamp(28px,4vw,46px) 0;
}
@media (min-width:680px){.footer-grid{grid-template-columns:repeat(3,minmax(0,1fr))}}

.footer-col-title{
  display:flex;align-items:center;gap:10px;
  margin-bottom:14px;
  font-family:var(--mono);font-size:11px;font-weight:500;letter-spacing:.18em;
  color:var(--cyan);
}
.footer-col-title::after{content:"";flex:1;height:1px;background:var(--line-soft)}
.footer-links li+li{margin-top:9px}
.footer-links a{
  font-size:14px;color:rgba(243,237,226,.76);
  border-bottom:1px solid transparent;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.footer-links a:hover{color:var(--cyan);border-bottom-color:rgba(27,224,212,.5)}

.footer-meta{
  display:grid;gap:14px;
  padding-top:clamp(22px,3vw,32px);
  border-top:1px solid var(--line);
}
.footer-contact{display:flex;flex-wrap:wrap;gap:8px 26px}
.footer-contact-item{font-size:13.5px;line-height:1.9;color:rgba(243,237,226,.76)}
.footer-contact-item b{
  margin-right:8px;
  font-family:var(--mono);font-size:10.5px;font-weight:500;letter-spacing:.12em;
  color:var(--mist);
}
.footer-hours{font-size:12.5px;line-height:1.85;color:var(--mist);max-width:64ch}
.footer-legal{display:flex;flex-wrap:wrap;gap:8px 16px;font-size:12.5px;color:var(--mist)}
.footer-legal li{display:flex;align-items:center;gap:16px}
.footer-legal li:not(:last-child)::after{content:"·";color:#39445A}
.footer-legal a{color:var(--mist);transition:color .2s var(--ease)}
.footer-legal a:hover{color:var(--cyan)}
.footer-copy{font-family:var(--mono);font-size:11px;letter-spacing:.05em;color:#56637A}

/* --- 15. 小屏收紧 ------------------------------------------------------ */
@media (max-width:600px){
  :root{--bar:58px}
  .brand-line{display:none}
  .brand-mark{width:30px;height:30px;font-size:11px}
  .header-tools{gap:8px}
  .header-tools .btn{padding:9px 12px;font-size:12px;letter-spacing:.02em}
  .nav-toggle{padding:8px 10px}
  .nav-toggle-text{display:none}
}

/* --- 16. 无障碍动效偏好 ------------------------------------------------ */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  .reveal-init{opacity:1;transform:none}
  .site-nav{transition:none}
}