/* =========================================================
   PA視訊指南 · /assets/site.css
   共享外壳：轨道导航头部 + 三层页脚 + 基础组件
   ========================================================= */

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

/* ---------- 2. TOKENS ---------- */
:root{
  --ink:#071A2B;
  --ink-2:#0B2233;
  --ink-3:#102C42;
  --slate:#33475B;
  --paper:#F4F1E8;
  --paper-2:#E9E4D6;
  --mint:#23E6B0;
  --teal:#0E8F73;
  --orange:#FF7A3D;
  --amber:#FFB547;
  --line:#8A99A8;
  --mist:#BFF7EA;
  --black:#0B0F14;

  --rail:272px;
  --gap:clamp(16px,2.2vw,28px);
  --shadow-hard:8px 8px 0 rgba(7,26,43,.9);
  --shadow-soft:8px 8px 0 rgba(7,26,43,.16);
  --ease:cubic-bezier(.2,.7,.3,1);

  --font-head:"Noto Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}

/* ---------- 3. BASE / 中文排版 ---------- */
body{
  background-color:var(--paper);
  background-image:
    linear-gradient(to right, rgba(51,71,91,.07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(51,71,91,.07) 1px, transparent 1px);
  background-size:64px 64px;
  color:var(--ink);
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.75;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{font-family:var(--font-head);font-weight:800;line-height:1.18;letter-spacing:.09em}
h1{font-size:clamp(34px,5vw,56px)}
h2{font-size:clamp(26px,3.4vw,40px)}
h3{font-size:clamp(20px,2.2vw,28px)}
p{max-width:74ch}
.mono{font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;line-height:1.6}
#main-content{scroll-margin-top:84px}
::selection{background:var(--mint);color:var(--ink)}

:where(a,button,summary,input,[tabindex]):focus-visible{
  outline:3px solid var(--mint);
  outline-offset:3px;
  box-shadow:0 0 0 7px rgba(7,26,43,.55);
}

/* ---------- 4. SKIP LINK ---------- */
.skip-link{
  position:fixed;top:10px;left:10px;z-index:300;
  padding:10px 18px;
  background:var(--mint);color:var(--ink);
  font-weight:800;font-size:14px;letter-spacing:.08em;
  border:2px solid var(--ink);
  transform:translateY(-200%);
  transition:transform .22s var(--ease);
}
.skip-link:focus,.skip-link:focus-visible{transform:translateY(0)}

/* ---------- 5. SCROLL PROGRESS ---------- */
.scroll-progress{
  position:fixed;top:0;left:0;right:0;height:3px;z-index:120;
  background:rgba(7,26,43,.22);pointer-events:none;
}
.scroll-progress-bar{
  display:block;height:100%;width:100%;
  transform:scaleX(0);transform-origin:0 50%;
  background:linear-gradient(90deg,var(--mint),var(--amber),var(--orange));
  transition:transform .12s linear;
}

/* ---------- 6. SITE HEADER / 轨道导航 ---------- */
.site-header{
  position:fixed;top:0;left:0;z-index:100;
  width:var(--rail);height:100vh;
  display:flex;flex-direction:column;
  background-color:var(--ink);
  background-image:repeating-linear-gradient(180deg,rgba(244,241,232,.05) 0 1px,transparent 1px 56px);
  color:var(--paper);
  border-right:1px solid rgba(35,230,176,.28);
}

.header-bar{
  display:flex;align-items:flex-start;justify-content:space-between;gap:12px;
  padding:26px 20px 20px;
  border-bottom:1px solid rgba(244,241,232,.14);
}

/* brand */
.brand{display:flex;align-items:center;gap:12px;min-width:0}
.brand-mark{
  position:relative;flex:0 0 auto;
  display:grid;place-items:center;
  width:46px;height:46px;overflow:hidden;
  border:2px solid var(--mint);
  background:rgba(35,230,176,.09);
  color:var(--mint);
  font-family:var(--font-head);font-weight:900;font-size:15px;letter-spacing:.06em;
}
.brand-mark-line{
  position:absolute;left:-12%;right:-12%;top:0;height:2px;
  background:var(--mint);opacity:.85;
  animation:scan-mark 4.4s var(--ease) infinite;
}
.brand-text{display:flex;flex-direction:column;gap:3px;min-width:0}
.brand-name{
  font-family:var(--font-head);font-weight:800;font-size:16px;
  letter-spacing:.1em;color:var(--paper);white-space:nowrap;
}
.brand-sub{
  font-family:var(--font-mono);font-size:9px;letter-spacing:.2em;
  color:rgba(244,241,232,.58);text-transform:uppercase;white-space:nowrap;
}

/* toggle */
.nav-toggle{display:none}
.nav-toggle-bar{display:block;width:16px;height:2px;background:currentColor}
.nav-toggle-label{font-family:var(--font-mono);font-size:11px;letter-spacing:.18em}

/* nav */
.site-nav{
  flex:1 1 auto;display:flex;flex-direction:column;
  padding:22px 16px 26px;overflow-y:auto;
}
.nav-kicker{
  font-family:var(--font-mono);font-size:10px;letter-spacing:.22em;
  color:var(--mint);opacity:.85;margin-bottom:14px;
}
.nav-list{display:flex;flex-direction:column;gap:2px}
.nav-item{min-width:0}
.nav-link{
  display:grid;grid-template-columns:32px 1fr auto;align-items:center;gap:10px;
  padding:11px 12px 11px 8px;
  border-left:2px solid transparent;
  color:rgba(244,241,232,.78);
  font-size:15px;font-weight:600;letter-spacing:.07em;
  transition:background .2s var(--ease),color .2s var(--ease),
             border-color .2s var(--ease),transform .2s var(--ease);
}
.nav-index{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;
  color:var(--line);
}
.nav-label{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.nav-tick{width:16px;height:2px;background:var(--line);opacity:.5;transition:width .2s var(--ease),background .2s var(--ease),opacity .2s var(--ease)}
.nav-link:hover{
  color:var(--paper);
  background:rgba(35,230,176,.09);
  border-left-color:var(--mint);
  transform:translateX(2px);
}
.nav-link:hover .nav-tick{width:24px;background:var(--mint);opacity:1}
.nav-link[aria-current="page"]{
  background:var(--mint);color:var(--ink);
  border-left-color:var(--mint);
  box-shadow:4px 4px 0 rgba(0,0,0,.42);
  transform:translateX(2px);
}
.nav-link[aria-current="page"] .nav-index{color:rgba(7,26,43,.72)}
.nav-link[aria-current="page"] .nav-tick{width:26px;background:var(--ink);opacity:1}

/* rail status + cta */
.header-rail-status{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  margin-top:auto;padding:14px 12px;
  border:1px solid rgba(35,230,176,.34);
  background:rgba(35,230,176,.07);
}
.status-dot{
  width:8px;height:8px;border-radius:50%;background:var(--mint);
  box-shadow:0 0 0 3px rgba(35,230,176,.2);
  animation:pulse 2.6s var(--ease) infinite;
}
.status-text{font-family:var(--font-mono);font-size:10px;letter-spacing:.14em;color:var(--mint)}
.status-meta{flex-basis:100%;font-family:var(--font-mono);font-size:10px;letter-spacing:.14em;color:var(--line)}
.rail-cta{
  display:flex;align-items:center;justify-content:space-between;gap:10px;
  margin-top:12px;padding:12px 14px;
  background:var(--orange);color:var(--ink);
  font-weight:800;font-size:14px;letter-spacing:.06em;
  border:2px solid var(--ink);
  box-shadow:4px 4px 0 rgba(0,0,0,.5);
  transition:transform .18s var(--ease),box-shadow .18s var(--ease),background .18s var(--ease);
}
.rail-cta::after{content:"→";font-family:var(--font-mono);font-weight:700}
.rail-cta:hover{transform:translate(-2px,-2px);box-shadow:6px 6px 0 rgba(0,0,0,.55);background:var(--amber)}
.rail-cta:active{transform:translate(1px,1px);box-shadow:2px 2px 0 rgba(0,0,0,.55)}

.nav-scrim{display:none}

@keyframes scan-mark{
  0%{transform:translateY(0);opacity:0}
  12%{opacity:.9}
  88%{opacity:.9}
  100%{transform:translateY(46px);opacity:0}
}
@keyframes pulse{
  0%,100%{box-shadow:0 0 0 3px rgba(35,230,176,.18)}
  50%{box-shadow:0 0 0 7px rgba(35,230,176,.06)}
}

/* ---------- 7. 基础布局组件 ---------- */
.container{width:min(1180px,100% - 2*clamp(18px,4vw,56px));margin-inline:auto}
.grid-12{display:grid;grid-template-columns:repeat(12,1fr);gap:var(--gap)}

.eyebrow{
  display:inline-flex;align-items:center;gap:10px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.22em;
  text-transform:uppercase;color:var(--teal);
}
.eyebrow::before{content:"";width:26px;height:2px;background:currentColor}

.scan-divider{
  position:relative;height:1px;margin-block:clamp(24px,4vw,48px);
  background:rgba(7,26,43,.2);
}
.scan-divider::after{
  content:"";position:absolute;left:0;top:-1px;width:72px;height:3px;background:var(--mint);
}

/* 面包屑 */
.breadcrumbs{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;
  color:var(--slate);margin-bottom:20px;
}
.breadcrumbs ol{display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.breadcrumbs li+li::before{content:"/";margin-right:8px;color:var(--line)}
.breadcrumbs a:hover{color:var(--teal)}
.breadcrumbs [aria-current="page"]{color:var(--ink);font-weight:700}

/* 按钮 */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:10px;
  padding:13px 22px;
  font-family:var(--font-body);font-weight:800;font-size:15px;letter-spacing:.07em;
  border:2px solid var(--ink);background:var(--paper);color:var(--ink);
  box-shadow:5px 5px 0 rgba(7,26,43,.85);
  cursor:pointer;
  transition:transform .18s var(--ease),box-shadow .18s var(--ease),background .18s var(--ease),color .18s var(--ease);
}
.btn:hover{transform:translate(-2px,-2px);box-shadow:7px 7px 0 rgba(7,26,43,.9)}
.btn:active{transform:translate(2px,2px);box-shadow:2px 2px 0 rgba(7,26,43,.9)}
.btn--primary{background:var(--mint);color:var(--ink)}
.btn--ghost{
  background:transparent;color:var(--paper);border-color:var(--mint);
  box-shadow:5px 5px 0 rgba(35,230,176,.22);
}
.btn--ghost:hover{background:rgba(35,230,176,.12);box-shadow:7px 7px 0 rgba(35,230,176,.26)}

/* 标签 */
.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 10px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;
  border:1px solid currentColor;
  color:var(--slate);background:rgba(191,247,234,.42);
}
.tag--ok{color:var(--teal);background:rgba(35,230,176,.2)}
.tag--warn{color:#B5410F;background:rgba(255,122,61,.18)}

/* 面板 */
.panel{
  position:relative;
  padding:clamp(18px,2.4vw,28px);
  border:2px solid var(--ink);
  background:var(--paper);
  box-shadow:var(--shadow-soft);
}
.panel--stack{box-shadow:12px 12px 0 rgba(7,26,43,.88)}
.panel--ink{background:var(--ink-2);color:var(--paper);border-color:var(--ink)}
.panel-head{
  display:flex;align-items:baseline;justify-content:space-between;gap:14px;
  padding-bottom:12px;margin-bottom:14px;
  border-bottom:1px solid rgba(7,26,43,.22);
}
.panel--ink .panel-head{border-bottom-color:rgba(244,241,232,.22)}
.panel-body{display:block}

/* 图片容器基础规则 */
.media-frame{
  position:relative;overflow:hidden;
  border:2px solid var(--ink);
  background:var(--ink-2);
  box-shadow:var(--shadow-soft);
}
.media-frame img,
.media-frame picture img,
.media-frame video{
  width:100%;height:100%;
  aspect-ratio:var(--ratio,16/10);
  object-fit:cover;
}
.media-frame::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:linear-gradient(180deg,rgba(7,26,43,0) 58%,rgba(7,26,43,.55));
  opacity:.9;
}
.media-caption{
  margin-top:9px;font-family:var(--font-mono);font-size:11px;
  letter-spacing:.12em;color:var(--slate);
}

/* 显现 */
[data-reveal]{
  opacity:0;transform:translateY(16px);
  transition:opacity .5s var(--ease),transform .5s var(--ease);
}
[data-reveal].is-visible{opacity:1;transform:none}

/* ---------- 8. SITE FOOTER ---------- */
.site-footer{
  position:relative;overflow:hidden;
  background-color:var(--ink);
  background-image:
    linear-gradient(to right,rgba(35,230,176,.06) 1px,transparent 1px),
    linear-gradient(to bottom,rgba(35,230,176,.06) 1px,transparent 1px);
  background-size:72px 72px;
  color:var(--paper);
  border-top:3px solid var(--mint);
}
.footer-inner{
  width:min(1180px,100% - 2*clamp(20px,4vw,56px));
  margin-inline:auto;
  padding:clamp(40px,6vw,76px) 0 26px;
}
.footer-top{
  padding-bottom:clamp(24px,3.4vw,38px);
  margin-bottom:clamp(28px,4vw,44px);
  border-bottom:1px solid rgba(244,241,232,.16);
}
.site-footer .eyebrow{color:var(--mint)}
.footer-wordmark{
  margin:14px 0 12px;
  font-size:clamp(30px,6vw,64px);
  letter-spacing:.1em;line-height:1.06;color:var(--paper);
}
.footer-tagline{
  font-size:15px;letter-spacing:.08em;
  color:rgba(244,241,232,.8);max-width:52ch;
}
.footer-status{
  margin-top:12px;font-size:11px;letter-spacing:.14em;
  color:var(--line);
}
.footer-grid{
  display:grid;grid-template-columns:1fr 1fr 1.5fr;
  gap:clamp(22px,4vw,48px);
}
.footer-col{min-width:0}
.footer-col-title{
  font-family:var(--font-mono);font-size:11px;font-weight:600;
  letter-spacing:.22em;color:var(--mint);
  padding-bottom:10px;margin-bottom:14px;
  border-bottom:1px solid rgba(35,230,176,.3);
}
.footer-links{display:flex;flex-direction:column;gap:10px}
.footer-link{
  display:inline-flex;align-items:center;gap:8px;
  font-size:15px;letter-spacing:.05em;color:rgba(244,241,232,.82);
  transition:color .18s var(--ease),transform .18s var(--ease);
}
.footer-link::before{
  content:"";width:10px;height:1px;background:var(--mint);opacity:.55;
  transition:width .18s var(--ease);
}
.footer-link:hover{color:var(--mint);transform:translateX(3px)}
.footer-link:hover::before{width:18px;opacity:1}

.footer-contact{display:grid;gap:12px}
.contact-row{
  display:grid;grid-template-columns:auto 1fr auto;align-items:center;
  gap:8px 14px;padding-bottom:10px;
  border-bottom:1px dashed rgba(244,241,232,.18);
}
.contact-label{
  font-family:var(--font-mono);font-size:10px;letter-spacing:.16em;
  color:var(--line);text-transform:uppercase;white-space:nowrap;
}
.contact-value{font-size:15px;color:var(--paper);word-break:break-word}
.copy-btn{
  font-family:var(--font-mono);font-size:10px;letter-spacing:.14em;
  padding:5px 10px;cursor:pointer;
  border:1px solid rgba(35,230,176,.55);color:var(--mint);
  transition:background .18s var(--ease),color .18s var(--ease);
}
.copy-btn:hover{background:var(--mint);color:var(--ink)}
.footer-note{
  margin-top:14px;font-size:11px;letter-spacing:.1em;
  color:rgba(244,241,232,.6);max-width:46ch;
}
.copy-note{
  min-height:1.4em;margin-top:8px;font-size:11px;letter-spacing:.1em;
  color:var(--mint);
}
.footer-bottom{
  display:flex;flex-wrap:wrap;align-items:center;gap:10px 26px;
  margin-top:clamp(30px,4vw,48px);padding-top:20px;
  border-top:1px dashed rgba(138,153,168,.4);
}
.footer-legal{
  font-size:11px;letter-spacing:.12em;
  color:rgba(244,241,232,.62);max-width:none;
}
.footer-legal--end{margin-left:auto;color:var(--line)}

/* ---------- 9. 平板 / 桌面 ---------- */
@media (min-width:981px){
  body{padding-left:var(--rail)}
  .scroll-progress{left:var(--rail)}
}

@media (max-width:1080px) and (min-width:981px){
  :root{--rail:248px}
  .brand-name{font-size:15px}
  .nav-link{font-size:14px;grid-template-columns:28px 1fr auto}
}

/* ---------- 10. 移动端：顶栏 + 抽屉 ---------- */
@media (max-width:980px){
  body{
    padding-left:0;
    font-size:16px;
    background-size:48px 48px;
  }
  .site-header{
    position:sticky;top:0;
    width:100%;height:auto;
    display:block;
    border-right:0;
    border-bottom:1px solid rgba(35,230,176,.32);
    box-shadow:0 10px 28px rgba(7,26,43,.28);
  }
  .header-bar{
    align-items:center;
    padding:12px 16px;
    min-height:62px;
    border-bottom:0;
  }
  .brand-mark{width:36px;height:36px;font-size:12px;border-width:2px}
  .brand-name{font-size:15px;letter-spacing:.08em}
  .brand-sub{font-size:8px;letter-spacing:.16em}

  .nav-toggle{
    display:inline-grid;
    grid-template-columns:16px auto;
    grid-auto-rows:min-content;
    align-items:center;
    gap:3px 10px;
    padding:9px 13px;
    border:1px solid rgba(35,230,176,.55);
    color:var(--mint);
    font-family:var(--font-mono);
    cursor:pointer;
    transition:background .18s var(--ease),color .18s var(--ease);
  }
  .nav-toggle:hover{background:rgba(35,230,176,.12)}
  .nav-toggle-bar{grid-column:1;transition:transform .24s var(--ease),opacity .2s var(--ease)}
  .nav-toggle-label{grid-column:2;grid-row:1 / span 2;line-height:1}
  .site-header[data-open="true"] .nav-toggle{background:var(--mint);color:var(--ink)}
  .site-header[data-open="true"] .nav-toggle-bar:nth-child(1){transform:translateY(2.5px) rotate(45deg)}
  .site-header[data-open="true"] .nav-toggle-bar:nth-child(2){transform:translateY(-2.5px) rotate(-45deg)}

  .site-nav{
    position:fixed;top:0;bottom:0;left:0;z-index:2;
    width:min(86vw,340px);
    padding:88px 20px 28px;
    background-color:var(--ink-2);
    background-image:repeating-linear-gradient(180deg,rgba(244,241,232,.05) 0 1px,transparent 1px 52px);
    border-right:1px solid rgba(35,230,176,.32);
    box-shadow:18px 0 48px rgba(0,0,0,.45);
    transform:translateX(-102%);
    visibility:hidden;
    transition:transform .3s var(--ease),visibility .3s var(--ease);
    overflow-y:auto;
  }
  .site-header[data-open="true"] .site-nav{transform:translateX(0);visibility:visible}
  .nav-kicker{margin-bottom:16px}
  .nav-link{font-size:16px;padding:14px 12px 14px 8px}
  .header-rail-status{margin-top:24px}
  .rail-cta{margin-top:14px}

  .nav-scrim{
    display:block;position:fixed;inset:0;z-index:1;
    background:rgba(7,26,43,.6);
    opacity:0;visibility:hidden;
    transition:opacity .28s var(--ease),visibility .28s var(--ease);
  }
  .site-header[data-open="true"] .nav-scrim{opacity:1;visibility:visible}
  body[data-nav-open="true"]{overflow:hidden}
  #main-content{scroll-margin-top:74px}
}

/* ---------- 11. 页脚响应式 ---------- */
@media (max-width:900px){
  .footer-grid{grid-template-columns:1fr 1fr}
  .footer-col--wide{grid-column:1 / -1}
  .footer-legal--end{margin-left:0}
}
@media (max-width:600px){
  .footer-grid{grid-template-columns:1fr}
  .footer-col--wide{grid-column:auto}
  .contact-row{grid-template-columns:1fr auto}
  .contact-label{grid-column:1 / -1;margin-bottom:-4px}
  .footer-bottom{flex-direction:column;align-items:flex-start;gap:8px}
  .footer-wordmark{letter-spacing:.08em}
}

/* ---------- 12. 减弱动态 ---------- */
@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;transform:none}
  .scroll-progress-bar{transition:none}
}