*{box-sizing:border-box;margin:0;padding:0}
:root{--bg:#f3f1ec;--paper:#fffefa;--ink:#1d2428;--muted:#687075;--faint:#969b9d;--line:#d8d7d2;--soft:#ebe9e3;--accent:#344d5b;--accent2:#263d49;--accent-soft:#edf1f2;--ok:#51655a;--ok-soft:#f1f4f1;--danger:#765a57}
body{background:var(--bg);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;color:var(--ink);line-height:1.55;-webkit-font-smoothing:antialiased}

.hub-top{position:sticky;top:0;z-index:50;display:flex;justify-content:space-between;align-items:center;padding:0 24px;height:56px;background:rgba(250,249,246,.94);backdrop-filter:blur(14px);border-bottom:1px solid var(--line)}
.hub-brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:inherit}
.hub-brand span{display:grid;place-items:center;width:34px;height:34px;border:1px solid #394247;border-radius:7px;font-size:11px;font-weight:800}
.hub-brand strong{font-size:14px;font-weight:650}
.hub-top nav{display:flex;align-items:center;gap:14px}
.hub-top nav a{font-size:12px;color:var(--muted);text-decoration:none}
.hub-top nav span{font-size:12px;color:var(--muted);max-width:120px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.hub-top nav button{border:1px solid var(--line);background:transparent;border-radius:7px;padding:6px 14px;font-size:12px;color:var(--muted);cursor:pointer;transition:background .12s ease;-webkit-tap-highlight-color:transparent}
.hub-top nav button:hover{background:var(--soft)}

.hub-wrap{max-width:780px;margin:0 auto;padding:32px 24px 60px}

.hub-hero{margin-bottom:28px}
.eyebrow{display:block;font-size:10px;letter-spacing:.14em;color:var(--faint);font-weight:650;margin-bottom:8px}
.hub-hero h1{font-family:"Songti SC","STSong","Noto Serif CJK SC",serif;font-size:26px;font-weight:700;letter-spacing:.01em;line-height:1.3}
.hub-hero p{font-size:13px;color:var(--muted);margin-top:10px;max-width:560px;line-height:1.65}

/* Progress strip */
.progress-strip{display:flex;gap:12px;margin-bottom:28px;animation:fadeIn .3s ease}
.progress-strip.hidden{display:none}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}
.stat-chip{flex:1;background:var(--paper);border:1px solid var(--line);border-radius:10px;padding:14px;text-align:center}
.stat-chip b{display:block;font-size:24px;font-weight:700;font-family:Georgia,serif;color:var(--ink)}
.stat-chip span{font-size:11px;color:var(--faint)}

.subject-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-bottom:32px}
.subject-card{display:block;background:var(--paper);border:1px solid var(--line);border-radius:12px;padding:24px;text-decoration:none;color:inherit;transition:transform .15s ease,box-shadow .15s ease,border-color .15s ease;-webkit-tap-highlight-color:transparent}
.subject-card:hover{transform:translateY(-2px);box-shadow:0 8px 24px rgba(20,30,40,.06);border-color:var(--accent)}
.subject-card small{display:block;font-size:9px;letter-spacing:.14em;color:var(--faint);font-weight:650;margin-bottom:8px}
.subject-card h2{font-family:"Songti SC","STSong",serif;font-size:20px;font-weight:700;margin-bottom:6px}
.subject-card p{font-size:12px;color:var(--muted);margin-bottom:14px;line-height:1.5}
.subject-card span{font-size:12px;color:var(--accent);font-weight:600}

.quiet-tools{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.quiet-tools a{display:flex;justify-content:space-between;align-items:center;gap:16px;padding:20px;background:transparent;border:1px solid var(--line);border-radius:10px;text-decoration:none;color:inherit;transition:background .12s ease;-webkit-tap-highlight-color:transparent}
.quiet-tools a:hover{background:var(--paper)}
.quiet-tools small{display:block;font-size:9px;letter-spacing:.12em;color:var(--faint);font-weight:650;margin-bottom:4px}
.quiet-tools strong{display:block;font-size:14px;font-weight:650;margin-bottom:4px}
.quiet-tools p{font-size:11px;color:var(--muted);line-height:1.5}
.quiet-tools > a > span{font-size:14px;color:var(--accent);white-space:nowrap;flex-shrink:0}

@media(max-width:680px){
  .hub-top{padding:0 16px}
  .hub-brand strong{font-size:12px}
  .hub-top nav a{display:none}
  .hub-wrap{padding:24px 16px 50px}
  .hub-hero h1{font-size:22px}
  .subject-grid{grid-template-columns:1fr;gap:10px}
  .subject-card{padding:18px}
  .quiet-tools{grid-template-columns:1fr;gap:10px}
  .quiet-tools a{padding:16px}
  .progress-strip{gap:8px}
  .stat-chip{padding:12px 8px}
  .stat-chip b{font-size:20px}
}