/* ==========================================================================
   星空赛事 Nebula Sprint · 共享样式表 /assets/site.css
   设计语言：深夜星空底 + 技术蓝图网格 + 6° 对角切分 + 霓虹数据描边
   ========================================================================== */

/* ---------- 01 变量 ---------- */
:root{
  --c-deep:#050A1F;
  --c-panel:#0C1330;
  --c-panel2:#111B3F;
  --c-nebula:#6C4BF4;
  --c-cyan:#00E5FF;
  --c-orange:#FF7A1A;
  --c-star:#F2F5FF;
  --c-grey:#98A3C6;
  --c-grid:#1B2A5E;
  --c-up:#2BD98A;
  --c-down:#FF3D6E;
  --c-notice:#FFD34D;

  --shell-w:1440px;
  --pad:96px;
  --gap:24px;
  --diag:6deg;

  --font-sans:"PingFang SC","HarmonyOS Sans","Noto Sans SC","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono","SFMono-Regular",ui-monospace,Menlo,Consolas,"Courier New",monospace;
  --font-cond:"Oswald","Barlow Condensed","Arial Narrow",var(--font-sans);

  --ease:cubic-bezier(.22,.61,.36,1);
  --t-fast:.12s;
  --t-base:.25s;
}

/* ---------- 02 Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  margin:0;
  min-height:100vh;
  font-family:var(--font-sans);
  font-size:17px;
  line-height:1.75;
  color:var(--c-star);
  background-color:var(--c-deep);
  background-image:
    radial-gradient(1120px 640px at 84% -10%,rgba(108,75,244,.30),transparent 62%),
    radial-gradient(760px 520px at 2% 16%,rgba(0,229,255,.10),transparent 66%),
    linear-gradient(to right,rgba(27,42,94,.52) 1px,transparent 1px),
    linear-gradient(to bottom,rgba(27,42,94,.52) 1px,transparent 1px);
  background-size:auto,auto,64px 64px,64px 64px;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
img,svg,video{display:block;max-width:100%;height:auto}
a{color:var(--c-cyan);text-decoration:none;transition:color var(--t-fast) var(--ease)}
a:hover{color:var(--c-star)}
button{font:inherit;color:inherit}
ul,ol{margin:0;padding:0;list-style:none}
h1,h2,h3,h4,h5,h6{margin:0;font-weight:800;letter-spacing:.08em;line-height:1.22}
p{margin:0 0 1em}
p:last-child{margin-bottom:0}
:focus-visible{outline:2px solid var(--c-cyan);outline-offset:3px}
::selection{background:var(--c-nebula);color:#fff}
#main-content{scroll-margin-top:96px}
[data-section]{scroll-margin-top:104px}

/* ---------- 03 版心与网格 ---------- */
.shell{
  width:100%;
  max-width:var(--shell-w);
  margin-inline:auto;
  padding-inline:var(--pad);
}
.grid-12{
  display:grid;
  grid-template-columns:repeat(12,minmax(0,1fr));
  gap:var(--gap);
}
.col-3{grid-column:span 3}
.col-4{grid-column:span 4}
.col-6{grid-column:span 6}
.col-8{grid-column:span 8}
.col-12{grid-column:span 12}

/* ---------- 04 排版 ---------- */
.type-display{
  font-family:var(--font-cond);
  font-weight:800;
  font-size:clamp(48px,9vw,120px);
  line-height:.94;
  letter-spacing:-.02em;
  font-variant-numeric:tabular-nums;
}
.type-display--glow{color:var(--c-orange);text-shadow:0 0 1px #FF7A1A,0 0 26px rgba(255,122,26,.55),0 0 64px rgba(255,122,26,.26)}
.type-display--star{color:var(--c-star);text-shadow:0 0 22px rgba(0,229,255,.34)}
.eyebrow{
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.26em;
  text-transform:uppercase;
  color:var(--c-cyan);
  margin:0 0 10px;
}
.chapter-num{
  font-family:var(--font-mono);
  font-size:clamp(28px,4vw,46px);
  font-weight:400;
  line-height:1;
  letter-spacing:.06em;
  color:var(--c-nebula);
}
.lead{
  font-size:clamp(17px,1.6vw,20px);
  line-height:1.7;
  color:var(--c-grey);
  max-width:68ch;
}
.section-head{
  display:flex;
  align-items:flex-end;
  gap:24px;
  flex-wrap:wrap;
  padding-bottom:16px;
  border-bottom:1px solid var(--c-grid);
  margin-bottom:32px;
}
.section-head h2{font-size:clamp(22px,2.6vw,30px)}
.section-head p{margin:0;color:var(--c-grey);font-size:15px;max-width:62ch}

/* ---------- 05 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.6em;
  padding:14px 26px;
  border:1px solid var(--c-grid);
  background:rgba(12,19,48,.72);
  color:var(--c-star);
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.16em;
  text-transform:uppercase;
  cursor:pointer;
  transition:border-color var(--t-fast) var(--ease),background var(--t-fast) var(--ease),color var(--t-fast) var(--ease),transform var(--t-fast) var(--ease);
}
.btn:hover{border-color:var(--c-cyan);color:var(--c-cyan);background:rgba(0,229,255,.08)}
.btn:active{transform:translateY(1px)}
.btn--primary{
  border-color:var(--c-orange);
  background:var(--c-orange);
  color:#1A0800;
  font-weight:700;
  box-shadow:0 0 24px -6px rgba(255,122,26,.9);
}
.btn--primary:hover{background:#FF9040;border-color:#FF9040;color:#1A0800}
.btn--ghost{border-color:var(--c-nebula);color:var(--c-star)}
.btn--ghost:hover{background:rgba(108,75,244,.20);border-color:var(--c-nebula);color:var(--c-star)}

/* ---------- 06 面板 / 卡片 / 标签 ---------- */
.panel{
  position:relative;
  background:var(--c-panel);
  border:1px solid var(--c-grid);
  padding:28px;
}
.panel--flush{padding:0}
.panel--accent{border-left:3px solid var(--c-nebula)}
.card{
  position:relative;
  display:flex;
  flex-direction:column;
  gap:14px;
  background:linear-gradient(180deg,rgba(17,27,63,.86),rgba(12,19,48,.86));
  border:1px solid var(--c-grid);
  padding:24px;
  transition:border-color var(--t-fast) var(--ease),transform var(--t-base) var(--ease);
}
.card:hover{border-color:var(--c-cyan);transform:translateY(-3px)}
.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:4px 9px;
  border:1px solid var(--c-grid);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  text-transform:uppercase;
  color:var(--c-grey);
  white-space:nowrap;
}
.tag--cyan{border-color:rgba(0,229,255,.55);color:var(--c-cyan)}
.tag--orange{border-color:rgba(255,122,26,.6);color:var(--c-orange)}
.tag--notice{border-color:rgba(255,211,77,.55);color:var(--c-notice)}
.tag--up{border-color:rgba(43,217,138,.55);color:var(--c-up)}
.tag--down{border-color:rgba(255,61,110,.55);color:var(--c-down)}

/* ---------- 07 面包屑与索引栏 ---------- */
.crumbs{
  display:flex;
  align-items:center;
  flex-wrap:wrap;
  gap:10px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.12em;
  color:var(--c-grey);
}
.crumbs a{color:var(--c-grey)}
.crumbs a:hover{color:var(--c-cyan)}
.crumbs__sep{color:var(--c-grid)}
.index-rail{
  position:sticky;
  top:96px;
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.1em;
}
.index-rail__item{
  display:flex;
  gap:10px;
  padding:10px 0 10px 14px;
  border-left:2px solid var(--c-grid);
  color:var(--c-grey);
  transition:color var(--t-fast) var(--ease),border-color var(--t-fast) var(--ease),background var(--t-base) var(--ease);
}
.index-rail__item:hover{color:var(--c-star);border-left-color:var(--c-cyan)}
.index-rail__item[aria-current="true"]{
  color:var(--c-star);
  border-left-color:var(--c-cyan);
  background:linear-gradient(90deg,rgba(0,229,255,.14),transparent);
}

/* ---------- 08 图片容器 ---------- */
.media{
  position:relative;
  display:block;
  overflow:hidden;
  background:var(--c-panel);
  border:1px solid var(--c-grid);
  width:100%;
}
.media::after{
  content:"";
  position:absolute;
  inset:0;
  background:linear-gradient(158deg,rgba(108,75,244,.26),rgba(5,10,31,.66) 62%);
  pointer-events:none;
}
.media img{width:100%;height:100%;object-fit:cover;filter:saturate(1.06) contrast(1.06)}
.media--wide{aspect-ratio:16/9}
.media--tall{aspect-ratio:3/4}
.media--square{aspect-ratio:1/1}
.media--diag{clip-path:polygon(0 0,100% 0,100% calc(100% - 6%),0 100%)}

/* ---------- 09 头部 ---------- */
.site-header{display:contents}

.skip-link{
  position:absolute;
  top:0;
  left:-9999px;
  z-index:999;
  padding:12px 20px;
  background:var(--c-cyan);
  color:#041226;
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.14em;
}
.skip-link:focus{left:12px;top:12px;color:#041226}

.brandbar{
  background:linear-gradient(90deg,#070E27 0%,#0C1330 46%,#0A1030 100%);
  border-bottom:1px solid var(--c-grid);
}
.brandbar__inner{
  display:flex;
  align-items:center;
  gap:28px;
  min-height:58px;
}
.brand{
  display:inline-flex;
  align-items:baseline;
  gap:10px;
  flex:0 0 auto;
  color:var(--c-star);
}
.brand:hover{color:var(--c-star)}
.brand__mark{
  width:12px;
  height:12px;
  background:var(--c-nebula);
  clip-path:polygon(50% 0,100% 50%,50% 100%,0 50%);
  box-shadow:0 0 12px rgba(0,229,255,.75);
  align-self:center;
}
.brand__name{font-size:18px;font-weight:800;letter-spacing:.16em}
.brand__sub{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.28em;
  text-transform:uppercase;
  color:var(--c-grey);
}
.brandbar__coords{
  display:flex;
  align-items:center;
  margin:0;
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.12em;
  color:var(--c-grey);
  white-space:nowrap;
}
.brandbar__coords span+span::before{
  content:"·";
  margin:0 12px;
  color:var(--c-nebula);
}
.brandbar__mail{
  margin-left:auto;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.08em;
  color:var(--c-cyan);
  border-bottom:1px solid transparent;
  white-space:nowrap;
}
.brandbar__mail:hover{color:var(--c-star);border-bottom-color:var(--c-cyan)}

.nav-toggle{
  display:none;
  align-items:center;
  gap:9px;
  margin-left:auto;
  padding:9px 14px;
  background:rgba(12,19,48,.85);
  border:1px solid var(--c-grid);
  color:var(--c-star);
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.16em;
  cursor:pointer;
  transition:border-color var(--t-fast) var(--ease),color var(--t-fast) var(--ease),background var(--t-fast) var(--ease);
}
.nav-toggle:hover{border-color:var(--c-cyan);color:var(--c-cyan)}
.nav-toggle[aria-expanded="true"]{
  border-color:var(--c-nebula);
  background:rgba(108,75,244,.22);
  color:var(--c-cyan);
}
.nav-toggle__bars{display:inline-block;width:16px}
.nav-toggle__bars i{
  display:block;
  height:2px;
  margin:3px 0;
  background:currentColor;
  transition:transform var(--t-fast) var(--ease),opacity var(--t-fast) var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:first-child{transform:translateY(5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:last-child{transform:translateY(-5px) rotate(-45deg)}

.navbar{
  position:sticky;
  top:0;
  z-index:80;
  background:rgba(5,10,31,.92);
  backdrop-filter:blur(12px);
  -webkit-backdrop-filter:blur(12px);
  border-bottom:1px solid var(--c-grid);
}
.navbar__inner{display:block}
.nav-list{display:flex;flex-wrap:wrap;gap:2px}
.nav-list a{
  display:flex;
  align-items:center;
  gap:9px;
  padding:18px 20px 16px;
  color:var(--c-grey);
  font-size:15px;
  letter-spacing:.06em;
  border-bottom:2px solid transparent;
  transition:color var(--t-fast) var(--ease),background var(--t-fast) var(--ease),border-color var(--t-fast) var(--ease);
}
.nav-list a:hover{color:var(--c-star);background:rgba(108,75,244,.14)}
.nav-list a[aria-current="page"]{
  color:var(--c-star);
  border-bottom-color:var(--c-nebula);
  background:linear-gradient(180deg,rgba(108,75,244,0),rgba(108,75,244,.20));
}
.nav-list__idx{
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.1em;
  color:var(--c-nebula);
}
.nav-list a[aria-current="page"] .nav-list__idx{color:var(--c-cyan)}

.scroll-progress{
  position:absolute;
  left:0;
  bottom:-1px;
  display:block;
  width:0;
  height:2px;
  background:linear-gradient(90deg,var(--c-nebula),var(--c-cyan));
  box-shadow:0 0 12px rgba(0,229,255,.7);
}

/* ---------- 10 页脚 ---------- */
.site-footer{
  position:relative;
  margin-top:96px;
  border-top:1px solid var(--c-grid);
  background:linear-gradient(180deg,rgba(12,19,48,.42),rgba(5,10,31,1) 70%);
}
.site-footer::before{
  content:"";
  position:absolute;
  top:-1px;
  left:0;
  right:0;
  height:2px;
  background:linear-gradient(90deg,var(--c-nebula),var(--c-cyan) 55%,transparent);
  opacity:.85;
}
.footer-grid{
  display:grid;
  grid-template-columns:1.5fr 1.1fr 1.4fr .9fr;
  gap:40px;
  padding-top:64px;
  padding-bottom:48px;
}
.footer-brand{
  margin:0 0 4px;
  font-size:20px;
  font-weight:800;
  letter-spacing:.16em;
  color:var(--c-star);
}
.footer-brand__sub{
  margin:0 0 16px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.28em;
  text-transform:uppercase;
  color:var(--c-nebula);
}
.footer-note{margin:0;font-size:14px;color:var(--c-grey);max-width:32ch}
.footer-label{
  margin:0 0 18px;
  font-family:var(--font-mono);
  font-size:12px;
  font-weight:400;
  letter-spacing:.22em;
  text-transform:uppercase;
  color:var(--c-cyan);
}
.footer-links{
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:10px 20px;
  font-size:14px;
}
.footer-links a{
  color:var(--c-grey);
  border-bottom:1px solid transparent;
  padding-bottom:2px;
}
.footer-links a:hover{color:var(--c-star);border-bottom-color:var(--c-cyan)}
.footer-contact{display:grid;gap:14px;font-size:14px}
.footer-contact li{display:grid;gap:3px}
.footer-contact span{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.18em;
  text-transform:uppercase;
  color:var(--c-grey);
}
.footer-contact strong{
  font-family:var(--font-mono);
  font-size:13px;
  font-weight:400;
  letter-spacing:.04em;
  color:var(--c-star);
  word-break:break-word;
}
.footer-filing{
  margin:0;
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.08em;
  line-height:2;
  color:var(--c-grey);
}
.footer-bottom{
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:16px;
  flex-wrap:wrap;
  padding-top:22px;
  padding-bottom:34px;
  border-top:1px solid var(--c-grid);
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.06em;
  color:var(--c-grey);
}
.footer-bottom p{margin:0}
.footer-bottom__hint{color:var(--c-notice)}

/* ---------- 11 显现协议 ---------- */
[data-reveal]{
  opacity:0;
  transform:translateY(14px);
  transition:opacity .5s var(--ease),transform .5s var(--ease);
}
[data-reveal].is-visible{opacity:1;transform:none}

/* ---------- 12 平板 ---------- */
@media (max-width:1279px){
  :root{--pad:56px}
}
@media (max-width:1023px){
  :root{--pad:40px}
  .grid-12{grid-template-columns:repeat(6,minmax(0,1fr))}
  .col-3,.col-4{grid-column:span 3}
  .col-6,.col-8{grid-column:span 6}
  .brandbar__mail{display:none}
  .brand__sub{display:none}
  .brandbar__inner{min-height:50px;gap:18px}
  .brandbar__coords{font-size:12px;letter-spacing:.08em}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:36px}
  .index-rail{position:static}
}
@media (max-width:900px){
  .nav-list a{padding:16px 14px 14px;font-size:14px}
}

/* ---------- 13 手机 ---------- */
@media (max-width:767px){
  :root{--pad:20px}
  body{
    font-size:16px;
    background-size:auto,auto,40px 40px,40px 40px;
  }
  .grid-12{grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
  .col-3,.col-4,.col-6,.col-8{grid-column:span 2}

  .brandbar__coords{display:none}
  .brandbar__inner{min-height:52px;gap:12px}
  .brand__name{font-size:16px;letter-spacing:.12em}
  .nav-toggle{display:inline-flex}

  .navbar__inner{display:block}
  .nav-list{display:block;max-height:0;overflow:hidden;transition:max-height var(--t-base) var(--ease)}
  [data-nav][data-open] .nav-list{max-height:520px}
  .nav-list li+li{border-top:1px solid var(--c-grid)}
  .nav-list a{padding:14px 0;border-bottom:0}
  .nav-list a[aria-current="page"]{
    background:rgba(108,75,244,.18);
    border-bottom-color:transparent;
    border-left:3px solid var(--c-nebula);
    padding-left:12px;
  }

  .section-head{flex-direction:column;align-items:flex-start;gap:12px}
  .panel{padding:20px}
  .card{padding:20px}
  .footer-grid{grid-template-columns:1fr;gap:32px;padding-top:44px;padding-bottom:32px}
  .footer-links{grid-template-columns:repeat(2,minmax(0,1fr))}
  .site-footer{margin-top:64px}
  .footer-bottom{flex-direction:column;align-items:flex-start;gap:8px}
}

/* ---------- 14 减弱动效 ---------- */
@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 !important;transform:none !important}
}