/* ===== 1. 变量 ===== */
:root{
  --bg-void:#050A14;
  --bg-section:#0B1424;
  --bg-panel:#12203A;
  --line:#1E3050;
  --line-soft:rgba(30,48,80,.6);
  --legacy:#6E7F99;
  --text-dim:#8FA3C2;
  --text:#E8F0FB;
  --cyan:#00E5C0;
  --cyan-press:#0E9E86;
  --gold:#F2B544;
  --rail-w:96px;
  --header-h:68px;
  --shell:1440px;
  --pad-x:clamp(20px,4vw,56px);
  --gap:clamp(16px,2.2vw,28px);
  --font-display:"Archivo Narrow","Oswald","Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --ease:cubic-bezier(.4,0,.2,1);
}

/* ===== 2. reset ===== */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:calc(var(--header-h) + 24px)}
body{
  margin:0;
  background:var(--bg-void);
  color:var(--text);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.85;
  letter-spacing:.01em;
  overflow-x:hidden;
}
img,picture,svg,video{display:block;max-width:100%}
img{height:auto;border:0}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
ul,ol{margin:0;padding:0;list-style:none}
h1,h2,h3,h4,p,figure,blockquote{margin:0}
h1,h2,h3,h4{font-weight:700;line-height:1.25;text-wrap:balance}
p{text-wrap:pretty}
::selection{background:var(--cyan);color:#04140F}
:focus-visible{outline:2px solid var(--cyan);outline-offset:3px}

/* ===== 3. 网格画布 ===== */
body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:0;
  pointer-events:none;
  background-image:
    linear-gradient(to right,var(--line-soft) 1px,transparent 1px),
    linear-gradient(to bottom,var(--line-soft) 1px,transparent 1px);
  background-size:96px 96px;
  opacity:.26;
}
body::after{
  content:"";
  position:fixed;
  inset:0;
  z-index:50;
  background:rgba(5,10,20,.74);
  opacity:0;
  visibility:hidden;
  pointer-events:none;
  transition:opacity .3s var(--ease),visibility .3s var(--ease);
}
body[data-nav-open="true"]::after{opacity:1;visibility:visible;pointer-events:auto}

main{position:relative;z-index:1;display:block}

@media (min-width:1024px){
  body{padding-left:var(--rail-w)}
}

/* ===== 4. 工具类 ===== */
.shell{width:100%;max-width:var(--shell);margin:0 auto;padding:0 var(--pad-x);position:relative;z-index:2}
.shell--narrow{max-width:920px}
.mono{font-family:var(--font-mono);font-size:13px;letter-spacing:.06em;color:var(--text-dim)}
.rule{height:1px;background:var(--line);border:0;margin:0}

/* ===== 5. skip link ===== */
.skip-link{
  position:absolute;
  left:12px;
  top:-64px;
  z-index:120;
  padding:10px 18px;
  background:var(--cyan);
  color:#04140F;
  font-size:13px;
  letter-spacing:.06em;
  transition:top .2s var(--ease);
}
.skip-link:focus{top:10px}

/* ===== 6. 按钮 ===== */
.btn{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:10px 18px;
  font-size:13px;
  letter-spacing:.06em;
  line-height:1.2;
  color:var(--text);
  background:transparent;
  border:1px solid var(--line);
  transition:background .24s var(--ease),color .24s var(--ease),border-color .24s var(--ease);
}
.btn--primary{border-color:var(--cyan);color:var(--cyan);background:rgba(0,229,192,.07)}
.btn--primary:hover{background:var(--cyan-press);border-color:var(--cyan-press);color:#04140F}
.btn--ghost:hover{border-color:var(--cyan);color:var(--cyan)}
.btn--block{display:flex;width:100%;justify-content:center}

/* ===== 7. 页头 ===== */
.site-header{
  position:sticky;
  top:0;
  z-index:60;
  background:#050A14;
  border-bottom:1px solid var(--line);
}
.site-header__inner{
  display:flex;
  align-items:center;
  gap:clamp(14px,2.2vw,30px);
  min-height:var(--header-h);
  max-width:var(--shell);
  margin:0 auto;
  padding:10px var(--pad-x);
}
.brand{
  display:flex;
  align-items:center;
  gap:12px;
  margin-right:auto;
  flex:0 0 auto;
}
.brand__mark{
  position:relative;
  width:10px;
  height:10px;
  flex:0 0 auto;
  background:var(--cyan);
}
.brand__mark::after{
  content:"";
  position:absolute;
  inset:-6px;
  border:1px solid var(--cyan);
  opacity:.5;
  animation:st-pulse 4s ease-in-out infinite;
}
@keyframes st-pulse{
  0%,100%{transform:scale(1);opacity:.5}
  50%{transform:scale(1.55);opacity:0}
}
.brand__text{display:flex;flex-direction:column;gap:1px;line-height:1.2}
.brand__name{
  font-family:var(--font-display);
  font-size:20px;
  font-weight:800;
  letter-spacing:-.01em;
  color:var(--text);
  font-style:normal;
}
.brand__sub{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.06em;
  color:var(--legacy);
}
.ver-legend{
  display:flex;
  align-items:center;
  gap:20px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.06em;
  color:var(--text-dim);
}
.ver-legend__item{display:inline-flex;align-items:center;gap:7px;white-space:nowrap}
.dot{
  display:inline-block;
  width:6px;
  height:6px;
  flex:0 0 auto;
  background:var(--legacy);
}
.dot--cyan{background:var(--cyan)}
.dot--legacy{background:var(--legacy)}
.dot--gold{background:var(--gold)}

/* 移动导航按钮 */
.nav-toggle{
  display:none;
  align-items:center;
  gap:9px;
  padding:9px 13px;
  border:1px solid var(--line);
  color:var(--text-dim);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  transition:color .24s var(--ease),border-color .24s var(--ease);
}
.nav-toggle:hover{color:var(--cyan);border-color:var(--cyan)}
.nav-toggle__bars{
  position:relative;
  width:16px;
  height:1px;
  background:currentColor;
  flex:0 0 auto;
}
.nav-toggle__bars::before,
.nav-toggle__bars::after{
  content:"";
  position:absolute;
  left:0;
  width:16px;
  height:1px;
  background:currentColor;
  transition:transform .24s var(--ease),opacity .24s var(--ease);
}
.nav-toggle__bars::before{top:-5px}
.nav-toggle__bars::after{top:5px}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before{transform:translateY(5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after{transform:translateY(-5px) rotate(-45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars{background:transparent}

/* ===== 8. 侧边轨道导航 ===== */
.site-nav{
  position:fixed;
  top:0;
  left:0;
  bottom:0;
  width:var(--rail-w);
  z-index:55;
  display:flex;
  flex-direction:column;
  justify-content:space-between;
  gap:18px;
  padding:24px 0 18px;
  background:#04080F;
  border-right:1px solid var(--line);
  overflow-y:auto;
  overscroll-behavior:contain;
}
.site-nav__badge{
  margin:0;
  text-align:center;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  color:var(--cyan);
}
.site-nav__badge::after{
  content:"";
  display:block;
  width:18px;
  height:1px;
  margin:10px auto 0;
  background:var(--line);
}
.site-nav__list{display:flex;flex-direction:column;gap:2px;padding:0;margin:0}
.site-nav__link{
  display:block;
  padding:11px 10px 11px 16px;
  font-size:13px;
  line-height:1.35;
  color:var(--text-dim);
  border-left:2px solid transparent;
  transition:color .24s var(--ease),background .24s var(--ease),border-color .24s var(--ease);
}
.site-nav__link:hover{color:var(--text);background:rgba(0,229,192,.06)}
.site-nav__link[aria-current="page"]{
  color:var(--cyan);
  border-left-color:var(--cyan);
  background:linear-gradient(90deg,rgba(0,229,192,.16),rgba(0,229,192,0));
}
.site-nav__status{
  display:flex;
  align-items:flex-start;
  gap:6px;
  padding:12px 10px 0;
  margin:0 10px;
  border-top:1px solid var(--line);
  font-family:var(--font-mono);
  font-size:10px;
  line-height:1.7;
  letter-spacing:.06em;
  color:var(--legacy);
}
.site-nav__status .dot{margin-top:7px}

/* ===== 9. 返回顶部 ===== */
.to-top{
  position:fixed;
  right:clamp(14px,2vw,28px);
  bottom:clamp(14px,2vw,28px);
  z-index:80;
  display:inline-flex;
  align-items:center;
  padding:9px 14px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.12em;
  color:var(--cyan);
  background:rgba(5,10,20,.94);
  border:1px solid var(--cyan);
  opacity:0;
  visibility:hidden;
  transform:translateY(8px);
  transition:opacity .24s var(--ease),transform .24s var(--ease),visibility .24s var(--ease),background .24s var(--ease),color .24s var(--ease);
}
.to-top[data-visible="true"]{opacity:1;visibility:visible;transform:none}
.to-top:hover{background:var(--cyan-press);color:#04140F}

/* ===== 10. 页脚 ===== */
.site-footer{
  position:relative;
  z-index:1;
  margin-top:clamp(56px,8vw,112px);
  background:#04080F;
  border-top:1px solid var(--line);
}
.site-footer__inner{
  display:grid;
  grid-template-columns:1.5fr 1fr 1fr 1.4fr;
  gap:clamp(24px,3vw,48px);
  max-width:var(--shell);
  margin:0 auto;
  padding:clamp(40px,5vw,72px) var(--pad-x) clamp(28px,3vw,44px);
}
.site-footer__brand .brand__name{font-size:24px;font-style:normal}
.site-footer__line{
  margin-top:8px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.08em;
  color:var(--cyan);
}
.site-footer__meta{
  margin-top:14px;
  max-width:30em;
  font-size:13px;
  line-height:1.8;
  color:var(--legacy);
}
.foot-title{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.18em;
  color:var(--legacy);
  margin-bottom:16px;
}
.foot-list li+li{margin-top:10px}
.foot-list a{
  font-size:14px;
  color:var(--text-dim);
  border-bottom:1px solid transparent;
  transition:color .24s var(--ease),border-color .24s var(--ease);
}
.foot-list a:hover{color:var(--cyan);border-bottom-color:var(--cyan)}
.foot-contact{display:flex;flex-direction:column;gap:10px;font-size:13.5px;line-height:1.7;color:var(--text-dim)}
.foot-contact p{display:flex;gap:10px;align-items:baseline}
.foot-k{
  flex:0 0 auto;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.08em;
  color:var(--legacy);
}
.site-footer__bottom{border-top:1px solid var(--line)}
.site-footer__bottom-inner{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:10px 24px;
  max-width:var(--shell);
  margin:0 auto;
  padding:18px var(--pad-x);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.06em;
  color:var(--legacy);
}

/* ===== 11. 章节头 / 卡片 / 栅格 ===== */
.sec-head{position:relative;padding-top:clamp(24px,4vw,56px)}
.sec-num{
  display:block;
  font-family:var(--font-display);
  font-weight:200;
  font-size:clamp(72px,10vw,112px);
  line-height:.8;
  letter-spacing:-.04em;
  color:transparent;
  -webkit-text-stroke:1px var(--line);
}
@supports not (-webkit-text-stroke:1px #000){
  .sec-num{color:var(--line)}
}
.sec-head__title{
  margin-top:14px;
  font-family:var(--font-display);
  font-size:clamp(28px,4vw,40px);
  font-weight:800;
  letter-spacing:-.02em;
  line-height:1.15;
}
.sec-head__lede{
  margin-top:14px;
  max-width:38em;
  font-size:15.5px;
  color:var(--text-dim);
}
.grid{display:grid;gap:var(--gap)}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.card{
  position:relative;
  background:var(--bg-panel);
  border:1px solid var(--line);
  padding:clamp(20px,2.6vw,32px);
}
.card--flat{background:var(--bg-section)}
.card__meta{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:12px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.08em;
  color:var(--text-dim);
}
.card__title{
  margin-top:12px;
  font-family:var(--font-display);
  font-size:24px;
  font-weight:700;
  line-height:1.32;
  letter-spacing:-.01em;
}
.card__text{margin-top:10px;font-size:15px;line-height:1.85;color:var(--text-dim)}

/* ===== 12. 标签 / 面包屑 / 筛选 ===== */
.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:3px 9px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.06em;
  border:1px solid var(--line);
  color:var(--text-dim);
}
.tag--cyan{color:var(--cyan);border-color:rgba(0,229,192,.45)}
.tag--legacy{color:var(--legacy);border-color:rgba(110,127,153,.5)}
.tag--gold{color:var(--gold);border-color:rgba(242,181,68,.45)}

.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:9px;
  padding:22px 0;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.08em;
  color:var(--legacy);
}
.breadcrumb a{color:var(--text-dim);transition:color .24s var(--ease)}
.breadcrumb a:hover{color:var(--cyan)}
.breadcrumb__sep{color:var(--line)}

.filter-bar{
  display:flex;
  flex-wrap:wrap;
  gap:8px;
  padding:14px 0;
  border-top:1px solid var(--line);
  border-bottom:1px solid var(--line);
}
.filter-btn{
  position:relative;
  padding:7px 14px 7px 27px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.06em;
  color:var(--text-dim);
  border:1px solid var(--line);
  background:transparent;
  transition:color .24s var(--ease),border-color .24s var(--ease),background .24s var(--ease);
}
.filter-btn::before{
  content:"";
  position:absolute;
  left:12px;
  top:50%;
  width:5px;
  height:5px;
  margin-top:-2.5px;
  background:var(--legacy);
  transition:background .24s var(--ease);
}
.filter-btn:hover{color:var(--text);border-color:var(--cyan-press)}
.filter-btn[aria-pressed="true"]{
  color:var(--cyan);
  border-color:var(--cyan);
  background:rgba(0,229,192,.08);
}
.filter-btn[aria-pressed="true"]::before{background:var(--cyan)}
[data-filter-item][hidden]{display:none}
.filter-empty{
  padding:32px 0;
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.06em;
  color:var(--legacy);
}

/* ===== 13. 图片容器（页面阶段放置占位）===== */
.media{
  position:relative;
  display:block;
  width:100%;
  overflow:hidden;
  background:var(--bg-section);
  border:1px solid var(--line);
}
.media>img,.media>.media__ph{display:block;width:100%;height:100%;object-fit:cover}
.media--16x9{aspect-ratio:16/9}
.media--4x3{aspect-ratio:4/3}
.media--1x1{aspect-ratio:1/1}
.media--3x4{aspect-ratio:3/4}
.media--wide{aspect-ratio:21/9}
.media__ph{
  min-height:180px;
  background:
    linear-gradient(135deg,rgba(0,229,192,.12),rgba(0,229,192,0) 46%),
    linear-gradient(315deg,rgba(242,181,68,.10),rgba(242,181,68,0) 42%),
    repeating-linear-gradient(90deg,var(--line) 0 1px,transparent 1px 30px),
    repeating-linear-gradient(0deg,var(--line) 0 1px,transparent 1px 30px),
    var(--bg-section);
}
.media__cap{
  padding-top:8px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.06em;
  color:var(--legacy);
}

/* ===== 14. 显现动效 ===== */
[data-reveal]{transition:opacity .55s var(--ease),transform .55s var(--ease)}
[data-reveal].is-armed{opacity:0;transform:translateY(14px)}
[data-reveal].is-armed.is-visible{opacity:1;transform:none}

/* ===== 15. 响应式 ===== */
@media (max-width:1199px){
  .ver-legend{display:none}
}
@media (max-width:1023px){
  .site-header__inner{gap:12px}
  .nav-toggle{display:inline-flex}
  .site-nav{
    top:0;
    left:0;
    bottom:0;
    width:min(320px,86vw);
    padding:calc(var(--header-h) + 18px) 0 28px;
    background:#070D18;
    transform:translateX(-101%);
    transition:transform .3s var(--ease);
  }
  .site-nav[data-open="true"]{transform:translateX(0)}
  .site-nav__badge{display:none}
  .site-nav__list{gap:0}
  .site-nav__link{font-size:15px;padding:14px 22px}
  .site-nav__status{margin:18px 22px 0;padding:16px 0 0;font-size:11px}
  .site-footer__inner{grid-template-columns:1fr 1fr}
  .grid--3{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (max-width:640px){
  body{font-size:15.5px}
  .site-footer__inner{grid-template-columns:1fr;gap:32px}
  .grid--2,.grid--3{grid-template-columns:minmax(0,1fr)}
  .card__title{font-size:20px}
  .site-footer__bottom-inner{flex-direction:column;align-items:flex-start;gap:8px}
}
@media (max-width:480px){
  .brand__name{font-size:17px}
  .brand__sub{display:none}
  .site-header__cta{display:none}
  .sec-num{font-size:64px}
}

/* ===== 16. 减少动态效果 ===== */
@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],
  [data-reveal].is-armed,
  [data-reveal].is-armed.is-visible{opacity:1 !important;transform:none !important}
  .to-top{transform:none}
}