:root{
  --bg:#121417; --panel:#1a1d21; --accent:#00d4aa; --accent2:#2e8bff;
  --text:#e8eaed; --muted:#9aa0a6; --line:#2a2e33;
}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:-apple-system,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",sans-serif;background:var(--bg);color:var(--text);line-height:1.6}
header{position:sticky;top:0;z-index:10;display:flex;align-items:center;justify-content:space-between;padding:14px 24px;background:rgba(18,20,23,.92);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.logo{font-weight:700;font-size:17px;color:var(--accent);white-space:nowrap}
nav a{color:var(--text);text-decoration:none;margin:0 10px;font-size:14px}
nav a:hover{color:var(--accent)}
.lang-btn{background:transparent;border:1px solid var(--accent);color:var(--accent);padding:5px 12px;border-radius:6px;cursor:pointer;font-size:13px}
.hero{padding:84px 24px;text-align:center;background:radial-gradient(1100px 380px at 50% -12%,rgba(0,212,170,.16),transparent)}
.hero h1{font-size:34px;margin-bottom:12px;line-height:1.25}
.hero .sub{color:var(--muted);max-width:700px;margin:0 auto 26px}
.cta{display:inline-block;background:var(--accent);color:#06231d;padding:12px 28px;border-radius:8px;font-weight:600;text-decoration:none}
.section{padding:56px 24px;max-width:1080px;margin:0 auto}
.section h2{font-size:25px;margin-bottom:8px}
.section .lead{color:var(--muted);margin-bottom:26px}
.group-title{margin:26px 0 12px;color:var(--accent2);font-size:18px}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:18px}
.card{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:22px}
.card h3{margin-bottom:8px;color:var(--accent2);font-size:17px}
.card .meta{color:var(--muted);font-size:14px}
footer{padding:30px 24px;text-align:center;color:var(--muted);font-size:13px;border-top:1px solid var(--line)}
.en{display:none}
body.lang-en .zh{display:none}
body.lang-en .en{display:block}
@media(max-width:640px){nav a{margin:0 6px;font-size:13px}.hero h1{font-size:26px}}