:root{
  --blue:#2E4A7A; --deep:#1F3557; --paper:#FAF7F0; --card:#EDF1F4;
  --ink:#2B2B2B; --line:#C9D3DE; --white:#fff;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--paper);color:var(--ink);
  font-family:"Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  font-size:16px;line-height:1.75}
h1,h2,h3,.serif{font-family:"Noto Serif SC","Songti SC","SimSun",Georgia,serif;color:var(--deep)}
a{color:var(--blue);text-decoration:none}
a:hover{text-decoration:underline}
header.site{background:var(--deep);color:#fff;position:sticky;top:0;z-index:50;
  box-shadow:0 2px 10px rgba(31,53,87,.25)}
.header-in{max-width:1080px;margin:0 auto;padding:10px 18px;display:flex;align-items:center;gap:14px;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:10px;color:#fff;font-family:"Noto Serif SC",serif;font-size:22px;letter-spacing:.15em}
.brand:hover{text-decoration:none}
.brand img{width:38px;height:38px}
nav.main{display:flex;gap:4px;flex-wrap:wrap;margin-left:auto}
nav.main a{color:#DCE6F2;padding:6px 10px;border-radius:6px;font-size:15px}
nav.main a:hover{background:rgba(255,255,255,.12);text-decoration:none;color:#fff}
nav.main a.on{background:rgba(255,255,255,.18);color:#fff}
.langsel{margin-left:8px}
.langsel select{font-size:14px;padding:5px 8px;border-radius:6px;border:1px solid var(--line);background:#fff;color:var(--deep)}
main{max-width:1080px;margin:0 auto;padding:0 18px 56px}
.hero{margin:0 -18px;padding:64px 18px 54px;text-align:center;color:#fff;position:relative;overflow:hidden;
  background:linear-gradient(160deg,#24406B 0%,#2E4A7A 55%,#3D5C8F 100%)}
.hero:before{content:"";position:absolute;inset:0;opacity:.16;
  background-image:radial-gradient(circle at 15% 30%,#fff 0 2px,transparent 3px),radial-gradient(circle at 82% 20%,#fff 0 2px,transparent 3px),radial-gradient(circle at 68% 78%,#fff 0 2px,transparent 3px),radial-gradient(circle at 28% 82%,#fff 0 1.5px,transparent 2.5px)}
.hero h1{color:#fff;font-size:52px;letter-spacing:.35em;margin:0 0 4px;text-indent:.35em}
.hero .en-name{font-family:Georgia,serif;letter-spacing:.3em;font-size:17px;color:#C9D6E8;margin-bottom:20px}
.hero .sub{font-size:21px;font-family:"Noto Serif SC",serif;letter-spacing:.06em}
.hero .tag{margin-top:14px;font-size:17px;color:#E8EEF6}
.hero img.mascot{width:92px;height:92px;margin-top:22px;filter:drop-shadow(0 6px 14px rgba(0,0,0,.3))}
.btns{margin-top:28px;display:flex;gap:14px;justify-content:center;flex-wrap:wrap}
.btn{display:inline-block;padding:11px 26px;border-radius:8px;font-size:16px;border:1.5px solid #fff}
.btn.solid{background:#fff;color:var(--deep);font-weight:600}
.btn.ghost{color:#fff}
.btn:hover{text-decoration:none;opacity:.9}
section{padding:38px 0 6px}
section h2{font-size:27px;border-bottom:2px solid var(--line);padding-bottom:10px;margin:0 0 20px}
.card{background:var(--card);border-radius:12px;padding:26px 28px}
.card p{margin:.55em 0}
.threads{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:14px}
.thread{background:#fff;border:1px solid var(--line);border-radius:10px;padding:16px 18px}
.thread b{color:var(--blue);font-family:"Noto Serif SC",serif;font-size:18px}
.course-group h3{margin:22px 0 8px;font-size:20px}
.course-list{list-style:none;margin:0;padding:0}
.course-list li{background:#fff;border:1px solid var(--line);border-radius:10px;margin:9px 0}
.course-list a{display:flex;justify-content:space-between;gap:12px;padding:13px 18px;color:var(--ink)}
.course-list a:hover{text-decoration:none;border-color:var(--blue)}
.course-list .go{color:var(--blue);white-space:nowrap}
.plat{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:16px}
.plat .p{background:#fff;border:1px solid var(--line);border-radius:12px;padding:20px 22px}
.plat h3{margin:0 0 4px;font-size:20px}
.plat .handle{color:var(--blue);font-size:14.5px;margin-bottom:8px}
.faq-item{background:#fff;border:1px solid var(--line);border-radius:10px;padding:18px 22px;margin:12px 0}
.faq-item h3{margin:0 0 6px;font-size:18.5px}
blockquote{margin:0;padding:4px 0 4px 18px;border-left:3px solid var(--blue)}
.note{font-size:14.5px;color:#5A6B82}
footer.site{background:var(--deep);color:#C9D6E8;margin-top:30px}
.footer-in{max-width:1080px;margin:0 auto;padding:30px 18px 36px;text-align:center}
footer.site .fname{font-family:"Noto Serif SC",serif;color:#fff;font-size:19px;letter-spacing:.2em}
footer.site img{width:44px;height:44px}
footer.site .plinks{margin:12px 0}
footer.site .plinks a{color:#C9D6E8;margin:0 9px;font-size:14.5px}
footer.site .small{font-size:13.5px;color:#93A7C0}
@media (max-width:640px){
  .hero h1{font-size:38px}
  .hero .sub{font-size:18px}
  nav.main a{padding:5px 7px;font-size:14px}
  .brand{font-size:19px}
  .card{padding:20px}
}