:root{
  --bg:#f5f8fc; --card:#ffffff; --ink:#1f2d3d; --sub:#5a6b7b;
  --brand:#1565c0; --brand2:#00897b; --line:#e2e8f0; --warn:#b45309;
  --ok:#2e7d32; --bad:#c62828; --soft:#eef4fb;
}
*{box-sizing:border-box}
body{margin:0;font-family:-apple-system,"PingFang SC","Microsoft YaHei",Segoe UI,Roboto,sans-serif;
  background:var(--bg);color:var(--ink);line-height:1.75;font-size:16px}
a{color:var(--brand);text-decoration:none}
.wrap{max-width:1080px;margin:0 auto;padding:0 16px}
header.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.95);
  backdrop-filter:blur(6px);border-bottom:1px solid var(--line)}
.nav .wrap{display:flex;align-items:center;gap:8px;flex-wrap:wrap;padding:10px 16px}
.logo{font-weight:800;color:var(--brand);margin-right:auto;font-size:17px}
.nav a{color:var(--sub);font-size:14px;padding:6px 10px;border-radius:8px}
.nav a:hover,.nav a.on{background:var(--soft);color:var(--brand)}
.hero{background:linear-gradient(135deg,#1565c0,#00897b);color:#fff;padding:46px 0 38px}
.hero h1{margin:0 0 10px;font-size:28px;line-height:1.3}
.hero p{margin:0;opacity:.95;max-width:780px}
.badges{display:flex;gap:8px;flex-wrap:wrap;margin-top:16px}
.badge{background:rgba(255,255,255,.18);border:1px solid rgba(255,255,255,.35);
  padding:5px 12px;border-radius:999px;font-size:13px}
section{padding:34px 0;border-bottom:1px solid var(--line)}
h2{font-size:22px;margin:0 0 6px;color:var(--ink)}
h2 .tag{font-size:12px;background:var(--soft);color:var(--brand);padding:3px 9px;
  border-radius:6px;margin-left:8px;vertical-align:middle}
h3{font-size:18px;color:var(--brand);margin:22px 0 8px}
.lead{color:var(--sub);margin:0 0 18px}
.card{background:var(--card);border:1px solid var(--line);border-radius:14px;
  padding:20px;margin:14px 0;box-shadow:0 1px 3px rgba(20,40,80,.04)}
.kp{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px}
.kp .card{margin:0}
.week{display:grid;grid-template-columns:120px 1fr;gap:14px;padding:14px 0;border-bottom:1px dashed var(--line)}
.week:last-child{border-bottom:none}
.wk-no{font-weight:800;color:var(--brand);font-size:18px}
.wk-no small{display:block;color:var(--sub);font-weight:500;font-size:12px}
.day{display:flex;gap:10px;padding:6px 0;border-bottom:1px dotted var(--line)}
.day:last-child{border-bottom:none}
.day .d{font-weight:700;color:var(--brand2);min-width:58px}
.day .c{color:var(--ink)}
.module h3{margin-top:0}
.pill{display:inline-block;font-size:12px;background:var(--soft);color:var(--brand2);
  padding:2px 9px;border-radius:6px;margin:2px 4px 2px 0}
.code{background:#0f1b2d;color:#d6e2f0;border-radius:10px;padding:12px 14px;
  font-family:Consolas,Menlo,monospace;font-size:13px;overflow:auto;margin:10px 0;white-space:pre}
.note{background:#fff8eb;border:1px solid #f2d8a8;color:#7a4d09;border-radius:10px;
  padding:10px 14px;font-size:14px;margin:12px 0}
.dl{display:inline-flex;align-items:center;gap:8px;background:var(--soft);border:1px solid var(--line);
  color:var(--brand);border-radius:10px;padding:8px 14px;margin:6px 8px 6px 0;font-size:14px}
.dl:hover{background:#e3edf8}
.dl small{color:var(--sub);font-size:12px}
.dlbox{border:1px dashed var(--brand);border-radius:12px;padding:16px;margin:12px 0;background:var(--soft)}
ul.tight li{margin:6px 0}
/* 练习 */
.quiz .q{font-weight:700;margin:14px 0 8px}
.opt{display:block;width:100%;text-align:left;background:var(--soft);border:1px solid var(--line);
  border-radius:10px;padding:10px 14px;margin:6px 0;cursor:pointer;font-size:15px;color:var(--ink)}
.opt:hover{background:#e3edf8}
.opt.right{background:#e7f5e9;border-color:#9ccc9e;color:var(--ok)}
.opt.wrong{background:#fdecea;border-color:#ef9a9a;color:var(--bad)}
.fb{font-size:14px;margin:6px 0 0;padding:8px 12px;border-radius:8px;display:none}
.fb.ok{display:block;background:#e7f5e9;color:var(--ok)}
.fb.no{display:block;background:#fdecea;color:var(--bad)}
.score{font-weight:800;color:var(--brand);margin-top:8px}
.tabs{display:flex;gap:6px;flex-wrap:wrap;margin:10px 0}
.tab{background:var(--soft);border:1px solid var(--line);border-radius:999px;
  padding:6px 14px;cursor:pointer;font-size:14px;color:var(--sub)}
.tab.on{background:var(--brand);color:#fff;border-color:var(--brand)}
.panel{display:none}.panel.on{display:block}
.hw-list li{margin:8px 0}
.step{display:flex;gap:12px;margin:10px 0}
.step .n{flex:none;width:26px;height:26px;border-radius:50%;background:var(--brand);color:#fff;
  display:flex;align-items:center;justify-content:center;font-weight:700;font-size:14px}
footer{background:#0f1b2d;color:#cdd9e8;padding:26px 0;font-size:13px}
footer a{color:#8ec5ff}
@media(max-width:640px){
  .hero h1{font-size:22px}.week{grid-template-columns:1fr}.nav a{font-size:13px;padding:5px 7px}
  h2{font-size:19px}body{font-size:15px}.code{font-size:12px}
}