:root{--green: #52B788;--green-light: #D8F3DC;--green-dark: #2D6A4F;--gold: #FFD43B;--gold-dark: #E67700;--orange: #FF922B;--orange-light: #FFE8CC;--blue: #74C0FC;--blue-light: #E7F5FF;--silver: #ADB5BD;--success: #40C057;--bg: #F0FAF4;--card: #FFFFFF;--text: #1B4332;--text-muted: #6C757D;--border: #D8F3DC;--radius-lg: 20px;--radius-md: 12px;--radius-sm: 8px;--shadow: 0 4px 20px rgba(0,0,0,.08);--shadow-sm: 0 2px 8px rgba(0,0,0,.06)}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}body{font-family:Nunito,system-ui,sans-serif;background:var(--bg);color:var(--text);min-height:100dvh;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:68px 16px 16px}#site-header{position:fixed;top:0;left:0;right:0;height:52px;background:var(--green-dark);color:#fff;display:flex;align-items:center;justify-content:space-between;padding:0 20px;z-index:100;box-shadow:0 2px 8px #00000026}#site-header.hidden{display:none}.header-logo{font-size:1.1rem;font-weight:800;letter-spacing:.02em}.header-user{font-size:.95rem;font-weight:700;opacity:.9;display:flex;align-items:center;gap:6px}#app{width:100%;max-width:480px;min-height:100dvh;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:16px}.card{background:var(--card);border-radius:var(--radius-lg);box-shadow:var(--shadow);padding:28px 24px;width:100%}.card-title{font-size:1.5rem;font-weight:800;color:var(--green-dark);margin-bottom:8px}.card-subtitle{font-size:1rem;color:var(--text-muted);margin-bottom:20px}button{font-family:inherit;font-weight:700;border:none;cursor:pointer;border-radius:var(--radius-md);transition:transform .1s,box-shadow .1s}button:active{transform:scale(.97)}.btn-primary{background:var(--green);color:#fff;font-size:1.1rem;padding:14px 28px;width:100%;box-shadow:0 4px 0 var(--green-dark)}.btn-primary:hover{background:#3da374}.btn-secondary{background:var(--blue-light);color:var(--green-dark);font-size:1rem;padding:12px 24px;width:100%}.btn-secondary:hover{background:var(--blue);color:#fff}.btn-gold{background:var(--gold);color:var(--gold-dark);font-size:1.1rem;padding:14px 28px;width:100%;box-shadow:0 4px 0 var(--gold-dark)}.btn-gold:hover{background:#ffc107}.btn-audio{background:var(--blue-light);color:var(--green-dark);font-size:1rem;padding:10px 20px;border-radius:50px;display:inline-flex;align-items:center;gap:8px;width:auto}.btn-audio:hover{background:var(--blue);color:#fff}.btn-sm{font-size:.9rem;padding:8px 16px;width:auto}input[type=text]{font-family:inherit;font-size:1.2rem;font-weight:700;color:var(--text);background:var(--green-light);border:2px solid var(--border);border-radius:var(--radius-md);padding:14px 16px;width:100%;text-align:center;outline:none;transition:border-color .15s}input[type=text]:focus{border-color:var(--green)}input[type=text]::placeholder{color:var(--text-muted);font-weight:400}.letter-display{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;margin:16px 0}.letter-slot{width:44px;height:52px;display:flex;align-items:center;justify-content:center;border-radius:var(--radius-sm);font-size:1.5rem;font-weight:800}.letter-slot.revealed{background:var(--green-light);color:var(--green-dark);border:2px solid var(--green)}.letter-slot.blank{background:var(--card);border:2px dashed var(--silver);color:transparent}.progress-bar-wrap{background:var(--green-light);border-radius:50px;height:12px;width:100%;overflow:hidden;margin:8px 0}.progress-bar-fill{background:var(--green);height:100%;border-radius:50px;transition:width .4s ease}.stats-row{display:flex;gap:12px;justify-content:space-between;margin-bottom:16px}.stat-chip{background:var(--green-light);border-radius:50px;padding:6px 14px;font-size:.95rem;font-weight:700;color:var(--green-dark);display:flex;align-items:center;gap:4px}.stat-chip.gold{background:#fff9db;color:var(--gold-dark)}.stat-chip.orange{background:var(--orange-light);color:#c44d01}.feedback{font-size:1.05rem;font-weight:700;text-align:center;padding:12px 16px;border-radius:var(--radius-md);min-height:48px;display:flex;align-items:center;justify-content:center;transition:all .2s}.feedback.correct{background:#ebfbee;color:var(--success)}.feedback.incorrect{background:var(--orange-light);color:#c44d01}.feedback.empty{background:transparent}.badge{display:inline-flex;align-items:center;justify-content:center;width:36px;height:36px;border-radius:50%;font-size:1.1rem}.badge.silver{background:#e9ecef;color:var(--silver)}.badge.gold{background:#fff9db;color:var(--gold-dark)}.badge.mastery{background:linear-gradient(135deg,#ffd43b,#40c057);color:#fff}.level-grid{display:flex;flex-direction:column;gap:10px;width:100%}.level-row{display:flex;align-items:center;gap:12px;background:var(--green-light);border-radius:var(--radius-md);padding:12px 16px;cursor:pointer;transition:background .15s}.level-row:hover{background:#c7eace}.level-row.locked{opacity:.5;cursor:default}.level-row.locked:hover{background:var(--green-light)}.level-num{font-size:1.1rem;font-weight:800;color:var(--green-dark);width:28px}.level-info{flex:1}.level-name{font-size:.9rem;font-weight:700;color:var(--green-dark)}.level-sub{font-size:.8rem;color:var(--text-muted)}.level-status{font-size:1.2rem}.checkbox-row{display:flex;align-items:center;gap:10px;font-size:.95rem;color:var(--text-muted);margin:12px 0;cursor:pointer}.checkbox-row input[type=checkbox]{width:20px;height:20px;accent-color:var(--green);cursor:pointer}.app-logo{font-size:2.5rem;text-align:center}.app-name{font-size:2rem;font-weight:800;color:var(--green-dark);text-align:center}.app-tagline{font-size:1rem;color:var(--text-muted);text-align:center;margin-bottom:8px}.celebrate{font-size:3rem;text-align:center;animation:pop .4s ease}@keyframes pop{0%{transform:scale(.5);opacity:0}70%{transform:scale(1.15)}to{transform:scale(1);opacity:1}}.mt-8{margin-top:8px}.mt-12{margin-top:12px}.mt-16{margin-top:16px}.mt-20{margin-top:20px}.text-center{text-align:center}.muted{color:var(--text-muted);font-size:.9rem}.divider{height:1px;background:var(--border);margin:16px 0}