:root{--bg: #0f1419;--surface: #1a2332;--surface-elevated: #243044;--border: #2d3f56;--text: #e8edf4;--text-muted: #8b9cb3;--primary: #3b82f6;--primary-hover: #2563eb;--primary-glow: rgba(59, 130, 246, .35);--secondary: #334155;--success: #22c55e;--warning: #eab308;--caution: #f97316;--error: #ef4444;--record: #ef4444;--record-glow: rgba(239, 68, 68, .4);--radius: 16px;--radius-sm: 10px;--shadow: 0 8px 32px rgba(0, 0, 0, .35);--font-sans: "Inter", system-ui, sans-serif;--font-chinese: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}body{font-family:var(--font-sans);background:var(--bg);color:var(--text);min-height:100vh;line-height:1.5;background-image:radial-gradient(ellipse 80% 50% at 50% -20%,rgba(59,130,246,.15),transparent),radial-gradient(ellipse 60% 40% at 100% 100%,rgba(34,197,94,.08),transparent)}.app{max-width:640px;margin:0 auto;padding:24px 20px 40px;min-height:100vh;display:flex;flex-direction:column}.header{display:flex;justify-content:space-between;align-items:flex-start;margin-bottom:32px;gap:16px}.logo{display:flex;align-items:center;gap:14px}.logo-icon{width:48px;height:48px;background:linear-gradient(135deg,var(--primary),#6366f1);border-radius:12px;display:flex;align-items:center;justify-content:center;font-family:var(--font-chinese);font-size:24px;font-weight:700;color:#fff;box-shadow:0 4px 16px var(--primary-glow)}.logo h1{font-size:1.35rem;font-weight:700;letter-spacing:-.02em}.tagline{font-size:.8rem;color:var(--text-muted);margin-top:2px}.stats{display:flex;gap:20px}.stat{text-align:center}.stat-value{display:block;font-size:1.25rem;font-weight:700;color:var(--primary)}.stat-label{font-size:.7rem;color:var(--text-muted);text-transform:uppercase;letter-spacing:.05em}.main{flex:1;display:flex;flex-direction:column;gap:20px}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow)}.card-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:20px}.badge{font-size:.75rem;font-weight:600;text-transform:uppercase;letter-spacing:.06em;color:var(--primary);background:#3b82f61f;padding:4px 10px;border-radius:20px}.btn-icon{background:var(--surface-elevated);border:1px solid var(--border);border-radius:var(--radius-sm);width:40px;height:40px;display:flex;align-items:center;justify-content:center;color:var(--text-muted);cursor:pointer;transition:all .2s}.btn-icon:hover{color:var(--text);border-color:var(--primary);background:#3b82f61a}.sentence-display{text-align:center;padding:12px 0 20px}.chinese{font-family:var(--font-chinese);font-size:2rem;font-weight:500;line-height:1.4;margin-bottom:12px;letter-spacing:.04em}.pinyin{font-size:1.05rem;color:var(--text-muted);margin-bottom:10px;font-style:italic}.english{font-size:.95rem;color:var(--text-muted);opacity:.85}.difficulty{display:flex;align-items:center;justify-content:center;gap:8px;padding-top:16px;border-top:1px solid var(--border)}.difficulty-label{font-size:.8rem;color:var(--text-muted)}.difficulty-badge{font-size:.75rem;font-weight:600;padding:3px 10px;border-radius:12px;background:var(--surface-elevated)}.difficulty-badge[data-level=beginner]{color:var(--success);background:#22c55e1f}.difficulty-badge[data-level=intermediate]{color:var(--warning);background:#eab3081f}.difficulty-badge[data-level=advanced]{color:var(--caution);background:#f973161f}.actions{display:flex;gap:12px}.btn{flex:1;display:flex;align-items:center;justify-content:center;gap:10px;padding:16px 20px;border:none;border-radius:var(--radius-sm);font-family:var(--font-sans);font-size:.95rem;font-weight:600;cursor:pointer;transition:all .2s}.btn:disabled{opacity:.5;cursor:not-allowed}.btn-secondary{background:var(--surface-elevated);color:var(--text);border:1px solid var(--border)}.btn-secondary:hover:not(:disabled){border-color:var(--primary);background:#3b82f614}.btn-primary{background:linear-gradient(135deg,var(--primary),#4f46e5);color:#fff;box-shadow:0 4px 16px var(--primary-glow)}.btn-primary:hover:not(:disabled){transform:translateY(-1px);box-shadow:0 6px 24px var(--primary-glow)}.btn-record.recording{background:linear-gradient(135deg,var(--record),#dc2626);box-shadow:0 4px 20px var(--record-glow);animation:pulse 1.5s ease-in-out infinite}.record-dot{width:8px;height:8px;border-radius:50%;background:#fff;display:none}.btn-record.recording .record-dot{display:block;animation:blink 1s ease-in-out infinite}@keyframes pulse{0%,to{box-shadow:0 4px 20px var(--record-glow)}50%{box-shadow:0 4px 32px var(--record-glow)}}@keyframes blink{0%,to{opacity:1}50%{opacity:.3}}.hint{margin-top:14px;font-size:.8rem;color:var(--caution);text-align:center;min-height:1.2em}.result-card{text-align:center;animation:fadeIn .4s ease}.result-card.hidden{display:none}@keyframes fadeIn{0%{opacity:0;transform:translateY(12px)}to{opacity:1;transform:translateY(0)}}.score-ring{position:relative;width:140px;height:140px;margin:0 auto 20px}.score-ring svg{width:100%;height:100%;transform:rotate(-90deg)}.score-bg{fill:none;stroke:var(--surface-elevated);stroke-width:8}.score-fill{fill:none;stroke-width:8;stroke-linecap:round;stroke-dasharray:326.73;stroke-dashoffset:326.73;transition:stroke-dashoffset .8s ease,stroke .3s}.score-text{position:absolute;top:0;right:0;bottom:0;left:0;display:flex;align-items:center;justify-content:center;gap:2px}.score-value{font-size:2.5rem;font-weight:700;line-height:1;transition:color .3s}.score-unit{font-size:1rem;color:var(--text-muted);align-self:flex-end;margin-bottom:6px}.feedback{font-size:1rem;color:var(--text);margin-bottom:24px;line-height:1.5}.playback{margin-bottom:24px}.playback.hidden{display:none}.btn-playback{width:100%;max-width:280px;margin:0 auto}.btn-playback.playing{border-color:var(--primary);color:var(--primary);background:#3b82f61a}#recording-audio{display:none}.comparison{background:var(--surface-elevated);border-radius:var(--radius-sm);padding:16px;margin-bottom:20px;text-align:left}.comparison-row{display:flex;flex-direction:column;gap:4px;padding:8px 0}.comparison-row+.comparison-row{border-top:1px solid var(--border)}.comparison-label{font-size:.7rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--text-muted)}.comparison-text{font-family:var(--font-chinese);font-size:1.1rem}.comparison-text.expected{color:var(--success)}.comparison-text.heard{color:var(--text)}.char-breakdown{display:flex;flex-wrap:wrap;gap:8px;justify-content:center}.char-chip{font-family:var(--font-chinese);font-size:1.25rem;width:40px;height:40px;display:flex;align-items:center;justify-content:center;border-radius:8px;border:2px solid transparent;cursor:default;transition:transform .15s}.char-chip:hover{transform:scale(1.1)}.char-correct{background:#22c55e26;border-color:var(--success);color:var(--success)}.char-tone{background:#eab30826;border-color:var(--warning);color:var(--warning)}.char-wrong{background:#ef444426;border-color:var(--error);color:var(--error)}.char-missing{background:#ef444414;border-color:#ef444466;color:var(--error);border-style:dashed}.char-extra{background:#8b9cb326;border-color:var(--text-muted);color:var(--text-muted)}.footer{margin-top:32px;text-align:center}.footer p{font-size:.75rem;color:var(--text-muted);opacity:.7}@media(max-width:480px){.header{flex-direction:column}.stats{width:100%;justify-content:center}.chinese{font-size:1.6rem}.actions{flex-direction:column}}