/* ============================================================
   星火社团 · 布局层 layout.css
   目录：1 容器与栅格 / 2 页头与导航 / 3 移动端抽屉 / 4 页脚 / 5 辅助布局 / 6 整页导出
   断点：桌面 >=1200px | 平板 768–1199px | 手机 <768px
   ============================================================ */

/* ---------- 1. 容器与栅格 ---------- */
.container{width:min(100% - 2rem, var(--container));margin-inline:auto}
.grid12{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:var(--gutter)}
.auto-grid{display:grid;gap:var(--gutter);grid-template-columns:repeat(auto-fill,minmax(min(260px,100%),1fr))}
.two-col{display:grid;grid-template-columns:minmax(0,1.6fr) minmax(0,1fr);gap:var(--sp-7)}
@media (max-width:1199px){
  .two-col{grid-template-columns:minmax(0,1.4fr) minmax(0,1fr);gap:var(--sp-6)}
}
@media (max-width:767px){
  :root{--gutter:1rem}
  .two-col{grid-template-columns:minmax(0,1fr)}
}
/* 跨列工具（移动端自动塌成单列） */
.col-6{grid-column:span 6}.col-4{grid-column:span 4}.col-8{grid-column:span 8}.col-12{grid-column:span 12}
@media (max-width:1199px){.col-6,.col-4{grid-column:span 12}.col-8{grid-column:span 12}}
@media (max-width:767px){[class*="col-"]{grid-column:span 12}}

/* ---------- 2. 页头与导航 ---------- */
/* 磨砂层放在 ::before 上：backdrop-filter 会让元素成为 fixed 后代的包含块，
   直接写在 .site-header 上会把抽屉/遮罩困在 64px 高的页头里（手机端抽屉打不开）。 */
.site-header{position:sticky;top:0;z-index:var(--z-header);background:transparent;border-bottom:1px solid var(--c-line);transition:box-shadow .25s var(--ease)}
.site-header::before{content:"";position:absolute;inset:0;z-index:-1;background:rgba(255,255,255,.78);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px)}
.site-header.is-scrolled{box-shadow:var(--sh-2)}
.header-inner{display:flex;align-items:center;justify-content:space-between;gap:var(--sp-5);min-height:var(--header-h)}
.logo{display:flex;align-items:center;gap:.625rem;font-weight:700;color:var(--c-ink);flex-shrink:0}
.logo-mark{width:2.25rem;height:2.25rem;border-radius:10px;background:linear-gradient(135deg,var(--c-primary),var(--c-accent));color:#fff;display:grid;place-items:center;font-size:1.125rem;line-height:1}
.logo-text{font-size:1.0625rem;line-height:1.15}
.logo-text small{display:block;font-size:var(--fs-xs);font-weight:400;color:var(--c-muted);line-height:1.2}

.nav{display:flex;align-items:center;gap:var(--sp-5)}
.nav-list{display:flex;align-items:center;gap:.125rem}
.nav-link{display:inline-flex;align-items:center;gap:.375rem;padding:.5rem .75rem;border-radius:var(--r-sm);color:var(--c-text);font-size:var(--fs-sm);font-weight:500;transition:.2s var(--ease)}
.nav-link:hover{color:var(--c-primary);background:var(--c-primary-100)}
.nav-link.is-active{color:var(--c-primary);font-weight:600;background:var(--c-primary-100)}
.nav-cta{margin-left:var(--sp-3)}

.has-sub{position:relative;display:flex;align-items:center}
.sub-toggle{display:grid;place-items:center;width:1.5rem;height:1.5rem;border-radius:var(--r-sm);color:var(--c-muted);transition:.2s var(--ease)}
.sub-toggle:hover{color:var(--c-primary);background:var(--c-primary-100)}
.has-sub.is-open .sub-toggle{transform:rotate(180deg);color:var(--c-primary)}
.sub-nav{position:absolute;top:calc(100% + .5rem);left:0;min-width:11.5rem;background:#fff;border:1px solid var(--c-line);border-radius:var(--r-md);box-shadow:var(--sh-2);padding:.5rem;opacity:0;visibility:hidden;transform:translateY(-6px);transition:.2s var(--ease)}
.sub-nav::before{content:"";position:absolute;inset:-.5rem -.5rem auto;height:.5rem}
.sub-nav a{display:block;padding:.5rem .75rem;border-radius:var(--r-sm);font-size:var(--fs-sm);color:var(--c-text);transition:.15s var(--ease)}
.sub-nav a:hover{background:var(--c-primary-100);color:var(--c-primary)}
.has-sub:hover .sub-nav,.has-sub:focus-within .sub-nav,.has-sub.is-open .sub-nav{opacity:1;visibility:visible;transform:translateY(0)}

/* 汉堡按钮 */
.hamburger{display:none;position:relative;width:2.75rem;height:2.75rem;border-radius:var(--r-sm);flex-direction:column;justify-content:center;align-items:center;gap:5px;border:1px solid var(--c-line);background:#fff}
.hamburger span{display:block;width:1.125rem;height:2px;background:var(--c-ink);border-radius:2px;transition:.25s var(--ease)}
.nav-scrim{position:fixed;inset:0;background:rgba(15,23,42,.45);z-index:calc(var(--z-drawer) - 1);animation:fade-in .25s var(--ease)}
@keyframes fade-in{from{opacity:0}to{opacity:1}}

/* ---------- 3. 平板 / 手机：导航收成抽屉 ---------- */
@media (max-width:1199px){
  .hamburger{display:inline-flex;z-index:calc(var(--z-drawer) + 2)}
  body.nav-open .hamburger span:nth-child(1){transform:translateY(7px) rotate(45deg)}
  body.nav-open .hamburger span:nth-child(2){opacity:0}
  body.nav-open .hamburger span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

  .nav{
    position:fixed;top:0;right:0;bottom:0;width:min(20rem,86vw);
    flex-direction:column;align-items:stretch;gap:0;
    background:#fff;z-index:var(--z-drawer);
    padding:calc(var(--header-h) + 1rem) 1.25rem 2rem;
    overflow-y:auto;overscroll-behavior:contain;
    transform:translateX(100%);transition:transform .3s var(--ease);
    box-shadow:-16px 0 40px rgba(15,23,42,.14);
  }
  body.nav-open .nav{transform:translateX(0)}
  .nav-list{flex-direction:column;align-items:stretch;gap:0}
  .nav-list>li{border-bottom:1px solid var(--c-line)}
  .nav-link{padding:.95rem .25rem;font-size:1rem;border-radius:0;background:none!important}
  .nav-link:hover{background:none!important}
  .nav-cta{margin:var(--sp-5) 0 0}

  /* 二级目录：移动端折叠展开，父项仍可点击进入落地页 */
  .has-sub{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center}
  .has-sub>.nav-link{grid-column:1}
  .sub-toggle{width:2.5rem;height:2.5rem;border:1px solid var(--c-line);border-radius:var(--r-sm)}
  .has-sub.is-open .sub-toggle{transform:none;background:var(--c-primary);color:#fff;border-color:var(--c-primary);rotate:180deg}
  .sub-nav{position:static;grid-column:1/-1;opacity:1;visibility:visible;transform:none;box-shadow:none;border:0;border-radius:0;padding:0;min-width:0;background:none;
    max-height:0;overflow:hidden;transition:max-height .3s var(--ease),padding .3s var(--ease)}
  .sub-nav::before{display:none}
  .has-sub.is-open .sub-nav{max-height:22rem;padding:0 0 .75rem .75rem}
  .sub-nav a{padding:.625rem .75rem;font-size:.95rem}
}

/* 手机：品牌区紧凑 */
@media (max-width:767px){
  .logo-text{font-size:1rem}
  .logo-text small{display:none}
}

/* ---------- 4. 页脚 ---------- */
.site-footer{margin-top:var(--sp-8);background:var(--c-ink);color:#CBD5E1;font-size:var(--fs-sm)}
.footer-grid{display:grid;grid-template-columns:minmax(0,1.4fr) repeat(3,minmax(0,1fr));gap:var(--sp-7);padding:var(--sp-8) 0 var(--sp-7)}
.footer-brand{display:flex;gap:.75rem;align-items:flex-start;color:#fff}
.footer-brand p{line-height:1.7}
.footer-brand small{color:#94A3B8}
.site-footer h3{color:#fff;font-size:.9375rem;margin-bottom:var(--sp-4)}
.site-footer li{margin-bottom:.625rem}
.site-footer a:hover{color:#fff;text-decoration:underline}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding:var(--sp-4) 0;color:#94A3B8;font-size:var(--fs-xs)}
@media (max-width:1199px){.footer-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:var(--sp-6)}}
@media (max-width:767px){
  .footer-grid{grid-template-columns:minmax(0,1fr);gap:var(--sp-5);padding:var(--sp-7) 0 var(--sp-5);text-align:center}
  .footer-brand{flex-direction:column;align-items:center;gap:.5rem}
  .site-footer h3{margin-bottom:var(--sp-3)}
  .site-footer nav ul{display:flex;flex-wrap:wrap;justify-content:center;gap:.5rem 1.125rem}
  .site-footer nav li{margin-bottom:0}
  .footer-bottom{text-align:center}
}

/* ---------- 5. 页内辅助 ---------- */
.page-hero{background:linear-gradient(135deg,var(--c-primary) 0%,#4A78F0 55%,var(--c-mint) 100%);color:#fff;padding:var(--sp-8) 0;position:relative;overflow:hidden}
.page-hero::after{content:"";position:absolute;right:-6rem;top:-6rem;width:22rem;height:22rem;border-radius:50%;background:rgba(255,255,255,.12)}
.page-hero h1{color:#fff;position:relative;z-index:1}
.page-hero p{color:rgba(255,255,255,.9);margin-top:var(--sp-3);position:relative;z-index:1}
.page-hero-meta{display:inline-flex;flex-wrap:wrap;gap:.35rem .75rem;align-items:center;margin-top:var(--sp-4)!important;padding:.5rem .875rem;border-radius:var(--r-full);background:rgba(255,255,255,.16);font-size:var(--fs-sm);color:#fff!important;position:relative;z-index:1}
.breadcrumb{display:flex;flex-wrap:wrap;gap:.5rem;align-items:center;font-size:var(--fs-sm);color:var(--c-muted);margin-bottom:var(--sp-4)}
.breadcrumb a:hover{color:var(--c-primary)}
.breadcrumb li:not(:last-child)::after{content:"/";margin-left:.5rem;color:var(--c-line)}

.to-top{position:fixed;right:1.25rem;bottom:1.5rem;z-index:90;width:2.75rem;height:2.75rem;border-radius:50%;background:var(--c-primary);color:#fff;display:grid;place-items:center;box-shadow:var(--sh-2);opacity:0;transform:translateY(10px);transition:.25s var(--ease);pointer-events:none}
.to-top.is-visible{opacity:1;transform:translateY(0);pointer-events:auto}
.to-top:hover{background:var(--c-primary-600)}
@media (max-width:767px){
  .to-top{right:.875rem;bottom:1rem;inset-inline-end:max(.875rem,env(safe-area-inset-right));bottom:max(1rem,env(safe-area-inset-bottom))}
}

/* ---------- 6. 整页导出（打印 / 长截图） ----------
   sticky 页头会被拼接式整页截图重复绘制在拼接缝上，并压住仅 45px 高的跑马灯；
   打印与 ?flat=1 模式让页头回到文档流，动效直接停在终态。 */
@media print{
  .site-header{position:static}
  .to-top,.nav-scrim{display:none!important}
  *{-webkit-print-color-adjust:exact;print-color-adjust:exact}
}
html.is-flat .site-header{position:static}
html.is-flat .to-top,html.is-flat .nav-scrim{display:none}
html.is-flat .reveal{opacity:1;animation:none}
html.is-flat .marquee-track{animation:none}
html.is-flat .timeline::before{transform:scaleY(1);transition:none}
html.is-flat .rank-bar i{transform:scaleX(1);transition:none}
html.is-flat .card.is-in{animation:none;opacity:1}