:root{
  --bg:#0b1220;
  --card:#0f1a30;
  --text:#e8eefc;
  --muted:#b9c7ee;
  --line:rgba(255,255,255,.10);
  --brand:#3aa6ff;
  --brand2:#73f0b4;
  --shadow:0 10px 30px rgba(0,0,0,.35);
}
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,"PingFang SC","Noto Sans CJK SC","Microsoft YaHei",sans-serif;
  color:var(--text);
  background:radial-gradient(1200px 500px at 20% 0%, rgba(58,166,255,.16), transparent 60%),
             radial-gradient(900px 400px at 80% 10%, rgba(115,240,180,.12), transparent 55%),
             var(--bg);
  line-height:1.75;
}
a{color:inherit;text-decoration:none}
a:hover{color:var(--brand)}
img{max-width:100%;height:auto;border-radius:14px}
code{background:rgba(255,255,255,.08);padding:.15rem .35rem;border-radius:8px}

.container{width:min(1100px,calc(100% - 32px));margin:0 auto}

/* 无障碍：仅屏幕阅读器可见 */
.sr-only{
  position:absolute !important;
  width:1px;height:1px;
  padding:0;margin:-1px;
  overflow:hidden;clip:rect(0,0,0,0);
  white-space:nowrap;border:0;
}

/* Skip link（键盘可访问） */
.skip-link{
  position:absolute;
  left:-9999px;
  top:10px;
  z-index:9999;
  padding:10px 12px;
  border-radius:12px;
  background:rgba(58,166,255,.95);
  color:#07101e;
  font-weight:700;
}
.skip-link:focus{
  left:12px;
  outline:2px solid rgba(115,240,180,.85);
  outline-offset:2px;
}

/* Header */
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(11,18,32,.78);
  border-bottom:1px solid var(--line);
  backdrop-filter: blur(10px);
}
.site-header-school{
  /* 学校版 header 包含 topbar，因此主区域略透明即可 */
  background:rgba(11,18,32,.72);
}
.topbar{
  border-bottom:1px solid rgba(255,255,255,.08);
  background:rgba(255,255,255,.02);
}
.topbar-inner{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  padding:8px 0;
  font-size:12px;
  color:rgba(185,199,238,.92);
}
.topbar-left{display:flex;gap:12px;flex-wrap:wrap}
.topbar-left span{opacity:.95}
.topbar-right{display:flex;gap:10px;flex-wrap:wrap;justify-content:flex-end}
.topbar-right a{
  color:var(--muted);
  border:1px solid rgba(255,255,255,.10);
  padding:4px 8px;
  border-radius:999px;
}
.topbar-right a:hover{border-color:rgba(58,166,255,.45);color:var(--text)}

.header-inner{
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding:14px 0;
}
.header-main{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
  padding:14px 0;
}
.brand{display:flex;align-items:center;gap:10px}
.brand-logo{border-radius:10px;background:rgba(255,255,255,.06);padding:6px}
.brand-text strong{display:block;font-size:15px;letter-spacing:.4px}
.brand-sub{display:block;font-style:normal;color:var(--muted);font-size:12px;margin-top:1px}

/* Search */
.search{
  display:flex;
  align-items:center;
  gap:8px;
  padding:6px 8px;
  border-radius:14px;
  border:1px solid rgba(255,255,255,.12);
  background:rgba(255,255,255,.02);
  min-width:min(420px, 52vw);
}
.search input{
  flex:1;
  border:0;
  outline:0;
  background:transparent;
  color:var(--text);
  font-size:13px;
}
.search input::placeholder{color:rgba(185,199,238,.75)}
.search button{
  border:1px solid rgba(255,255,255,.18);
  background:rgba(11,18,32,.55);
  color:var(--text);
  padding:8px 12px;
  border-radius:12px;
  cursor:pointer;
}
.search button:hover{border-color:rgba(58,166,255,.55)}

.nav{display:flex;gap:12px;flex-wrap:wrap;justify-content:flex-end}
.nav a{
  padding:8px 10px;border-radius:10px;
  border:1px solid rgba(255,255,255,.06);
  color:var(--muted);
  transition:all .15s ease;
}
.nav a:hover{border-color:rgba(58,166,255,.35);color:var(--text)}
.nav a.is-active{background:rgba(58,166,255,.14);border-color:rgba(58,166,255,.35);color:var(--text)}

/* Mega nav + 下拉 */
.nav-mega{
  border-top:1px solid rgba(255,255,255,.06);
  border-bottom:1px solid rgba(255,255,255,.06);
  background:rgba(255,255,255,.01);
}
.nav-inner{
  display:flex;
  align-items:center;
  justify-content:flex-start;
  gap:10px;
  flex-wrap:wrap;
  padding:10px 0;
}
.nav-item{position:relative}
.nav-link{display:inline-flex;align-items:center;gap:6px}
.has-dropdown > .nav-link::after{
  content:"▾";
  font-size:12px;
  opacity:.75;
  margin-top:1px;
}
.dropdown{
  position:absolute;
  top:calc(100% + 8px);
  left:0;
  min-width:220px;
  padding:10px;
  border-radius:14px;
  border:1px solid rgba(255,255,255,.14);
  background:rgba(11,18,32,.95);
  box-shadow:0 18px 40px rgba(0,0,0,.35);
  display:none;
}
.dropdown a{
  display:block;
  padding:8px 10px;
  border-radius:12px;
  border:1px solid transparent;
  color:rgba(232,238,252,.92);
  white-space:nowrap;
}
.dropdown a:hover{
  background:rgba(58,166,255,.10);
  border-color:rgba(58,166,255,.30);
}
.nav-item.has-dropdown:hover .dropdown,
.nav-item.has-dropdown:focus-within .dropdown{
  display:block;
}

/* Breadcrumb */
.breadcrumb{border-bottom:1px solid var(--line);background:rgba(255,255,255,.02)}
.breadcrumb .container{padding:10px 0;display:flex;align-items:center;gap:10px;font-size:13px;color:var(--muted)}
.breadcrumb-item{color:var(--muted)}
.breadcrumb-item:hover{color:var(--text)}
.breadcrumb-current{color:var(--text)}
.breadcrumb-sep{opacity:.7}

/* Hero */
.hero{padding:26px 0 12px}
.hero-inner{display:grid;grid-template-columns:1.1fr .9fr;gap:18px;align-items:center}
.hero-text h1{margin:.2rem 0 0;font-size:28px;line-height:1.25}
.hero-text p{margin:.75rem 0;color:var(--muted)}
.hero-bullets{
  margin:10px 0 12px 18px;
  color:var(--muted);
}
.hero-bullets li{margin:6px 0}
.dyn-paragraph{
  margin:10px 0 12px;
  padding:10px 12px;
  border:1px dashed rgba(255,255,255,.14);
  border-radius:14px;
  background:rgba(255,255,255,.02);
  color:rgba(185,199,238,.95);
}
.hero-cta{display:flex;gap:12px;flex-wrap:wrap;margin:14px 0}
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  padding:10px 14px;border-radius:12px;
  background:linear-gradient(135deg, rgba(58,166,255,.95), rgba(115,240,180,.90));
  color:#07101e;font-weight:700;
  box-shadow:var(--shadow);
}
.btn:hover{filter:brightness(1.02)}
.btn.btn-ghost{
  background:transparent;color:var(--text);
  border:1px solid rgba(255,255,255,.16);
  box-shadow:none;
}
.btn.btn-ghost:hover{border-color:rgba(58,166,255,.45)}
.meta{font-size:12px}
.hero-media img{border:1px solid rgba(255,255,255,.10)}

/* Home（学校版） */
.banner{padding:18px 0 8px}
.hero-school{padding:18px 0 10px}
.hero-school-inner{
  display:grid;
  grid-template-columns:1.15fr .85fr;
  gap:16px;
  align-items:stretch;
}
.hero-school-text h1{margin:.2rem 0 0;font-size:28px;line-height:1.25}
.hero-school-text p{margin:.75rem 0;color:var(--muted)}
.hero-school-cards{
  display:grid;
  grid-template-columns:1fr;
  gap:10px;
  align-content:start;
}
.mini-card{
  display:flex;
  flex-direction:column;
  gap:4px;
  padding:14px 14px;
  border-radius:16px;
  border:1px solid rgba(255,255,255,.12);
  background:rgba(255,255,255,.02);
  box-shadow:0 10px 26px rgba(0,0,0,.20);
}
.mini-card strong{font-size:15px}
.mini-card span{color:var(--muted);font-size:13px}
.mini-card:hover{border-color:rgba(58,166,255,.45)}

.home-columns{padding:8px 0 4px}
.cols-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
.col-card{
  background:rgba(255,255,255,.02);
  border:1px solid rgba(255,255,255,.10);
  border-radius:18px;
  padding:16px;
  box-shadow:0 10px 26px rgba(0,0,0,.18);
}
.col-card h3{margin:0 0 10px;font-size:16px}
.col-desc{margin:0 0 10px;color:var(--muted)}
.col-list{margin:0 0 10px 18px;color:var(--muted)}
.col-list li{margin:6px 0}
.more{
  display:inline-flex;
  align-items:center;
  gap:6px;
  color:var(--brand);
  font-weight:650;
}
.more:hover{text-decoration:underline}

.support-center{padding:8px 0 4px}
.support-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.support-card{
  border-radius:18px;
  border:1px solid rgba(255,255,255,.10);
  background:rgba(255,255,255,.02);
  padding:16px;
  box-shadow:0 10px 26px rgba(0,0,0,.18);
}
.support-card h3{margin:0 0 8px;font-size:16px}
.support-card p{margin:0;color:var(--muted)}
.support-card:hover{border-color:rgba(58,166,255,.45)}

.quick-links{padding:8px 0 18px}

/* Carousel */
.carousel{
  position:relative;
  width:100%;
  border-radius:16px;
  overflow:hidden;
  border:1px solid rgba(255,255,255,.10);
  background:rgba(255,255,255,.03);
}
.carousel-track{position:relative}
.carousel-slide{display:none}
.carousel-slide.is-active{display:block}
.carousel-slide img{display:block;width:100%;height:auto;border-radius:0}
.carousel-btn{
  position:absolute;top:50%;
  transform:translateY(-50%);
  width:38px;height:38px;
  border-radius:12px;
  border:1px solid rgba(255,255,255,.18);
  background:rgba(11,18,32,.55);
  color:var(--text);
  cursor:pointer;
  display:flex;align-items:center;justify-content:center;
  font-size:22px;
  backdrop-filter: blur(8px);
}
.carousel-btn:hover{border-color:rgba(58,166,255,.55)}
.carousel-btn.prev{left:10px}
.carousel-btn.next{right:10px}
.carousel-dots{
  position:absolute;left:0;right:0;bottom:10px;
  display:flex;gap:8px;justify-content:center;align-items:center;
}
.carousel-dots .dot{
  width:10px;height:10px;border-radius:999px;
  border:1px solid rgba(255,255,255,.30);
  background:rgba(255,255,255,.12);
  cursor:pointer;
}
.carousel-dots .dot.is-active{
  background:rgba(58,166,255,.85);
  border-color:rgba(58,166,255,.85);
}

/* Sections */
.section-title{margin:22px 0 12px;font-size:20px}
.card-group{padding:14px 0}
.card-list{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.info-card{
  background:rgba(255,255,255,.03);
  border:1px solid rgba(255,255,255,.10);
  border-radius:16px;
  padding:16px;
  box-shadow:0 10px 26px rgba(0,0,0,.22);
}
.info-card h3{margin:0 0 8px;font-size:16px}
.info-card p{margin:0 0 10px;color:var(--muted)}
.card-link{color:var(--brand);font-weight:650}

.content-block{padding:14px 0 6px}
.inline-links{display:flex;gap:10px;flex-wrap:wrap;margin-top:10px}
.inline-links a{border:1px solid rgba(255,255,255,.12);padding:8px 10px;border-radius:12px;color:var(--muted)}
.inline-links a:hover{border-color:rgba(58,166,255,.45);color:var(--text)}

/* Article */
.article{padding:14px 0 0}
.rich{
  background:rgba(255,255,255,.02);
  border:1px solid rgba(255,255,255,.10);
  border-radius:18px;
  padding:18px;
}
.rich h1{margin:.2rem 0 10px;font-size:26px;line-height:1.25}
.rich h2{margin:18px 0 8px;font-size:18px}
.rich h3{margin:14px 0 8px;font-size:16px}
.rich p{margin:10px 0;color:var(--muted)}
.rich strong{color:var(--text)}
.rich ul,.rich ol{margin:10px 0 12px 20px;color:var(--muted)}
.rich li{margin:6px 0}
.rich a{color:var(--brand)}
.rich a:hover{text-decoration:underline}

.figure{margin:14px 0}
.figure img{border:1px solid rgba(255,255,255,.10)}
.figure figcaption{margin-top:8px;color:rgba(185,199,238,.92);font-size:13px}

/* FAQ */
.faq{padding:12px 0 8px}
.faq-list{
  background:rgba(255,255,255,.02);
  border:1px solid rgba(255,255,255,.10);
  border-radius:18px;
  padding:6px;
}
.faq-item{border-top:1px solid rgba(255,255,255,.08)}
.faq-item:first-child{border-top:0}
.faq-q{
  width:100%;
  text-align:left;
  background:transparent;
  border:0;
  color:var(--text);
  padding:12px 12px;
  cursor:pointer;
  font-size:15px;
  display:flex;
  gap:6px;
  align-items:flex-start;
}
.faq-q span{color:var(--brand)}
.faq-a{padding:0 12px 12px 12px;color:var(--muted);display:none}
.faq-item.is-open .faq-a{display:block}
.faq-item.is-open .faq-q{color:var(--brand2)}

/* Link hub */
.link-hub{padding:12px 0 26px}
.link-hub-title{margin:18px 0 6px;font-size:18px}
.link-hub-desc{margin:0 0 10px;color:var(--muted)}
.link-hub-grid{
  display:grid;grid-template-columns:repeat(3,1fr);gap:14px;
  background:rgba(255,255,255,.02);
  border:1px solid rgba(255,255,255,.10);
  border-radius:18px;
  padding:16px;
}
.link-hub-col h3{margin:0 0 8px;font-size:15px}
.link-hub-links{display:flex;flex-wrap:wrap;gap:10px}
.ilink{
  border:1px solid rgba(255,255,255,.12);
  padding:8px 10px;border-radius:12px;
  color:var(--muted);
}
.ilink:hover{border-color:rgba(58,166,255,.45);color:var(--text)}

/* Footer */
.site-footer{border-top:1px solid var(--line);background:rgba(255,255,255,.02)}
.footer-inner{padding:22px 0;display:grid;gap:14px}
.footer-top{
  display:flex;
  align-items:flex-start;
  justify-content:space-between;
  gap:16px;
  flex-wrap:wrap;
}
.footer-quick-link h3{margin:0 0 8px;font-size:15px}
.link-row{display:flex;gap:10px;flex-wrap:wrap}
.link-row a{color:var(--muted);border:1px solid rgba(255,255,255,.12);padding:8px 10px;border-radius:12px}
.link-row a:hover{border-color:rgba(58,166,255,.45);color:var(--text)}
.footer-terms{
  display:flex;
  gap:12px;
  flex-wrap:wrap;
  justify-content:flex-end;
  align-items:center;
  padding-top:26px; /* 与左侧标题行对齐 */
}
.footer-terms a{color:var(--muted);font-size:13px}
.footer-terms a:hover{color:var(--text)}
.footer-copyright{color:var(--muted);font-size:13px}
.footer-meta{opacity:.9}

/* 404 */
.page-404 .notfound{padding:60px 0}
.page-404 h1{margin:0 0 10px}
.notfound-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:14px}
.notfound-meta{color:var(--muted);font-size:12px;margin-top:12px}

/* Responsive */
@media (max-width: 920px){
  .hero-inner{grid-template-columns:1fr}
  .hero-school-inner{grid-template-columns:1fr}
  .cols-grid{grid-template-columns:1fr}
  .support-grid{grid-template-columns:1fr}
  .card-list{grid-template-columns:1fr}
  .link-hub-grid{grid-template-columns:1fr}
  .footer-terms{justify-content:flex-start;padding-top:0}
  .search{min-width:0;width:100%}
  .header-main{flex-direction:column;align-items:flex-start}
}