:root { --bg:#0a0e1a;--card-bg:#131b2e;--surface:#1a2740;--accent:#3b82f6;--accent2:#f59e0b;--text:#e2e8f0;--muted:#64748b;--correct:#22c55e;--wrong:#ef4444;--border:#1e3150;--tab-bg:#0f1525; }
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:-apple-system,'Segoe UI',system-ui,sans-serif;background:var(--bg);color:var(--text);min-height:100dvh;display:flex;flex-direction:column;align-items:center;user-select:none;-webkit-tap-highlight-color:transparent}
.topbar{width:100%;max-width:540px;display:flex;align-items:center;justify-content:space-between;padding:14px 20px;position:sticky;top:0;z-index:10;backdrop-filter:blur(12px);background:rgba(10,14,26,0.85)}
.topbar h1{font-size:1.1rem;font-weight:700}.topbar h1 span{color:var(--accent2)}
.tabs{display:flex;gap:0;width:100%;max-width:540px;background:var(--tab-bg);border-bottom:1px solid var(--border);position:sticky;top:52px;z-index:9}
.tab{flex:1;text-align:center;padding:12px 6px;font-size:0.85rem;font-weight:600;cursor:pointer;border:none;background:none;color:var(--muted);border-bottom:2px solid transparent;transition:all 0.2s}
.tab:hover{color:var(--text)}.tab.active{color:var(--accent);border-bottom-color:var(--accent)}
.page{display:none;width:100%;max-width:540px;flex:1;padding:12px 16px 40px}.page.active{display:block}
.categories{display:flex;flex-wrap:wrap;gap:6px;justify-content:center;margin-bottom:14px}
.cat-pill{padding:5px 12px;border-radius:16px;font-size:0.75rem;font-weight:600;cursor:pointer;border:1.5px solid var(--border);background:transparent;color:var(--muted);transition:all 0.2s;white-space:nowrap}
.cat-pill:hover{border-color:var(--accent);color:var(--text)}.cat-pill.active{background:var(--accent);border-color:var(--accent);color:#fff}
.card-wrap{perspective:1000px;width:100%;height:380px;margin:0 auto 12px;cursor:pointer}
.card{width:100%;height:100%;position:relative;transform-style:preserve-3d;transition:transform 0.45s cubic-bezier(0.4,0,0.2,1);border-radius:20px}
.card.flipped{transform:rotateY(180deg)}
.face{position:absolute;width:100%;height:100%;backface-visibility:hidden;border-radius:20px;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:24px 18px;text-align:center;border:1px solid var(--border);overflow-y:auto}
.front{background:linear-gradient(145deg,#152037 0%,#0f1525 100%)}
.back{background:linear-gradient(145deg,#1a3050 0%,#0f1525 100%);transform:rotateY(180deg)}
.tag{font-size:0.7rem;color:var(--accent);font-weight:700;text-transform:uppercase;letter-spacing:0.06em;margin-bottom:8px}
.french{font-size:1.9rem;font-weight:800;color:#fff;margin-bottom:10px;line-height:1.3;letter-spacing:-0.01em}
.phonetic{font-size:0.9rem;color:var(--muted);margin-bottom:4px}
.chinese{font-size:1.7rem;font-weight:700;color:var(--accent2);margin-bottom:14px}
.hint{font-size:0.85rem;color:var(--muted)}
.ctrls{display:flex;align-items:center;gap:10px;margin-bottom:10px;justify-content:center;flex-wrap:wrap}
.btn{padding:9px 16px;border-radius:12px;font-size:0.85rem;font-weight:600;cursor:pointer;border:none;transition:all 0.15s;white-space:nowrap}
.btn-nav{background:var(--surface);color:var(--text);border:1px solid var(--border)}.btn-nav:hover{background:var(--border)}
.btn-sound{background:var(--accent);color:#fff;width:44px;height:44px;border-radius:50%;font-size:1.2rem;padding:0}.btn-sound:hover{filter:brightness(1.15)}
.btn-known{background:#14532d;color:#4ade80;font-size:0.8rem;padding:7px 14px}
.btn-unknown{background:#7f1d1d;color:#fca5a5;font-size:0.8rem;padding:7px 14px}
.btn-start{background:var(--accent);color:#fff;font-size:1rem;padding:12px 28px;border-radius:14px;font-weight:700;margin:20px auto;display:block}.btn-start:hover{filter:brightness(1.15)}
.dots{display:flex;gap:4px;flex-wrap:wrap;justify-content:center;margin-bottom:8px;max-height:36px;overflow-y:auto}
.dot{width:5px;height:5px;border-radius:50%;background:var(--border);flex-shrink:0}.dot.known{background:var(--correct)}.dot.current{background:var(--accent);transform:scale(1.6)}
.kbd{font-size:0.65rem;color:var(--muted);text-align:center;margin-top:6px;padding-bottom:12px}
.kbd kbd{background:var(--surface);padding:1px 5px;border-radius:3px;border:1px solid var(--border);font-size:0.65rem}
.option{display:block;width:100%;text-align:left;padding:10px 12px;margin-bottom:4px;border-radius:10px;border:1.5px solid var(--border);background:var(--card-bg);color:var(--text);font-size:0.8rem;cursor:pointer;transition:all 0.15s}
.option:hover{border-color:var(--accent);background:#1a2740}
.option.correct-answer{border-color:var(--correct);background:#0a2e1a;color:#4ade80}
.option.wrong-answer{border-color:var(--wrong);background:#2e0a0a;color:#fca5a5}
.option:disabled{cursor:default;opacity:0.7}
.exam-correct-label{font-size:1.4rem;font-weight:700;margin-bottom:10px}.exam-correct-label.pass{color:var(--correct)}.exam-correct-label.fail{color:var(--wrong)}
.exam-explain-text{font-size:0.8rem;color:var(--muted);line-height:1.5;text-align:center}
.exam-counter{text-align:center;font-size:0.8rem;color:var(--muted);margin-bottom:8px}
.mock-timer{font-size:2.5rem;font-weight:800;font-variant-numeric:tabular-nums;text-align:center;margin-bottom:8px}
.mock-timer.warn{color:var(--accent2)}.mock-timer.danger{color:var(--wrong);animation:pulse 1s infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:0.5}}
.mock-progress{text-align:center;font-size:0.8rem;color:var(--muted);margin-bottom:14px}
.mock-score{text-align:center;font-size:0.85rem;color:var(--muted);margin-bottom:4px}
.mock-nav{display:flex;gap:8px;justify-content:center;margin-top:16px}
.mock-setup{text-align:center;padding:30px 0}.mock-setup h2{font-size:1.4rem;margin-bottom:8px;color:var(--text)}.mock-setup p{color:var(--muted);font-size:0.85rem;margin-bottom:20px}
.mock-results{text-align:center;padding:20px}.mock-results .big-emoji{font-size:4rem;margin-bottom:10px}.mock-results .score{font-size:2.5rem;font-weight:800;margin-bottom:4px;color:var(--text)}.mock-results .msg{color:var(--muted);margin-bottom:20px}
.result-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px;max-width:280px;margin:0 auto 20px}
.result-card{background:var(--surface);border-radius:12px;padding:14px;text-align:center;border:1px solid var(--border)}
.result-card .val{font-size:1.5rem;font-weight:800}.result-card .val.green{color:var(--correct)}.result-card .val.red{color:var(--wrong)}.result-card .val.blue{color:var(--accent)}.result-card .val.amber{color:var(--accent2)}.result-card .lbl{font-size:0.65rem;color:var(--muted);margin-top:2px}
.stat-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px;margin-bottom:16px}
.stat-card{background:var(--surface);border-radius:14px;padding:16px;text-align:center;border:1px solid var(--border)}
.stat-card .val{font-size:1.8rem;font-weight:800}.stat-card .val.accent{color:var(--accent2)}.stat-card .val.green{color:var(--correct)}.stat-card .lbl{font-size:0.7rem;color:var(--muted);margin-top:4px}
.stat-card.wide{grid-column:span 2}.stat-card h3{font-size:0.8rem;color:var(--muted);margin-bottom:10px;text-align:left}
.bar-row{display:flex;align-items:center;gap:8px;margin-bottom:7px}
.bar-label{width:70px;font-size:0.7rem;color:var(--muted);text-align:right;flex-shrink:0}
.bar-track{flex:1;height:8px;background:var(--border);border-radius:4px;overflow:hidden}
.bar-fill{height:100%;border-radius:4px;transition:width 0.6s;background:var(--accent)}
.bar-pct{width:40px;font-size:0.7rem;color:var(--muted);text-align:right}
@media(max-width:400px){.card-wrap{height:320px}.french{font-size:1.5rem}.chinese{font-size:1.4rem}}