:root{--color-bg: #f8f7f4;--color-surface: #ffffff;--color-surface-raised: #f0ede8;--color-border: #e2ddd8;--color-text: #1a1814;--color-text-muted: #6b6560;--color-target: #f5c842;--color-target-dark: #c49a0a;--color-tile: #e8e4de;--color-tile-hover: #ddd9d2;--color-correct: #4caf50;--color-incorrect: #f44336;--color-primary: #3a7bd5;--color-primary-dark: #2c62b0;--radius-sm: 6px;--radius-md: 10px;--radius-lg: 16px;--shadow-sm: 0 1px 3px rgba(0,0,0,.08);--shadow-md: 0 4px 12px rgba(0,0,0,.1);--shadow-tile: 0 2px 4px rgba(0,0,0,.12);--font-base: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;--transition: .15s ease}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html,body,#root{height:100%}body{font-family:var(--font-base);background:var(--color-bg);color:var(--color-text);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}#root{display:flex;flex-direction:column;max-width:600px;margin:0 auto;min-height:100%}.page{flex:1;padding:16px 16px 80px;overflow-y:auto}.page-header{margin-bottom:20px}.page-title{font-size:22px;font-weight:700;color:var(--color-text)}.page-subtitle{font-size:14px;color:var(--color-text-muted);margin-top:4px}.bottom-nav{position:fixed;bottom:0;left:50%;transform:translate(-50%);width:100%;max-width:600px;background:var(--color-surface);border-top:1px solid var(--color-border);display:flex;z-index:100}.nav-item{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:10px 0;gap:3px;color:var(--color-text-muted);text-decoration:none;font-size:11px;font-weight:500;transition:color var(--transition);cursor:pointer;background:none;border:none}.nav-item.active,.nav-item:hover{color:var(--color-primary)}.nav-item svg{width:22px;height:22px}.card{background:var(--color-surface);border-radius:var(--radius-md);padding:16px;box-shadow:var(--shadow-sm);border:1px solid var(--color-border)}.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;padding:12px 20px;border-radius:var(--radius-md);font-size:15px;font-weight:600;cursor:pointer;border:none;transition:all var(--transition);min-height:44px;text-decoration:none;font-family:var(--font-base)}.btn-primary{background:var(--color-primary);color:#fff}.btn-primary:hover:not(:disabled){background:var(--color-primary-dark)}.btn-secondary{background:var(--color-surface-raised);color:var(--color-text);border:1px solid var(--color-border)}.btn-secondary:hover:not(:disabled){background:var(--color-tile-hover)}.btn-target{background:var(--color-target);color:#1a1200}.btn-target:hover:not(:disabled){background:var(--color-target-dark);color:#fff}.btn-danger{background:#fce8e6;color:#c62828;border:1px solid #ef9a9a}.btn-full{width:100%}.btn:disabled{opacity:.4;cursor:not-allowed}.btn-sm{padding:8px 14px;font-size:13px;min-height:36px}.form-group{display:flex;flex-direction:column;gap:6px;margin-bottom:16px}.form-label{font-size:13px;font-weight:600;color:var(--color-text-muted);text-transform:uppercase;letter-spacing:.04em}.form-input,.form-textarea,.form-select{background:var(--color-surface);border:1.5px solid var(--color-border);border-radius:var(--radius-sm);padding:12px 14px;font-size:16px;font-family:var(--font-base);color:var(--color-text);width:100%;transition:border-color var(--transition);min-height:44px}.form-textarea{resize:vertical;min-height:80px}.form-input:focus,.form-textarea:focus,.form-select:focus{outline:none;border-color:var(--color-primary)}.form-input-row{display:flex;gap:8px;align-items:center}.form-input-row .form-input{flex:1}.toast{position:fixed;bottom:90px;left:50%;transform:translate(-50%);background:#333;color:#fff;padding:10px 20px;border-radius:20px;font-size:14px;font-weight:500;z-index:200;animation:toast-in .2s ease,toast-out .2s ease 2.3s forwards;white-space:nowrap}@keyframes toast-in{0%{opacity:0;transform:translate(-50%) translateY(10px)}to{opacity:1;transform:translate(-50%) translateY(0)}}@keyframes toast-out{0%{opacity:1}to{opacity:0}}.spinner{width:32px;height:32px;border:3px solid var(--color-border);border-top-color:var(--color-primary);border-radius:50%;animation:spin .7s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.loading-overlay{position:absolute;inset:0;background:#ffffffd9;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:12px;border-radius:inherit;z-index:10;font-size:14px;color:var(--color-text-muted)}.tile{display:inline-flex;align-items:center;justify-content:center;padding:10px 14px;border-radius:var(--radius-sm);font-size:16px;font-weight:500;cursor:pointer;-webkit-user-select:none;user-select:none;box-shadow:var(--shadow-tile);transition:transform var(--transition),box-shadow var(--transition),opacity var(--transition);min-height:44px;white-space:nowrap}.tile-neutral{background:var(--color-tile);color:var(--color-text);border:1.5px solid #d4cec7}.tile-target{background:var(--color-target);color:#1a1200;border:1.5px solid #d4a800}.tile:hover{transform:translateY(-2px);box-shadow:0 4px 8px #00000029}.tile:active{transform:scale(.96)}.flex-row{display:flex;align-items:center;gap:8px}.flex-col{display:flex;flex-direction:column;gap:8px}.text-muted{color:var(--color-text-muted);font-size:14px}.badge{display:inline-flex;align-items:center;padding:2px 8px;border-radius:10px;font-size:12px;font-weight:600}.badge-new{background:#e3f2fd;color:#1565c0}.badge-learning{background:#fff3e0;color:#e65100}.badge-review{background:#e8f5e9;color:#2e7d32}.badge-relearning{background:#fce4ec;color:#880e4f}.divider{height:1px;background:var(--color-border);margin:16px 0}.step-indicator{display:flex;gap:6px;align-items:center;margin-bottom:20px}.step-dot{width:8px;height:8px;border-radius:50%;background:var(--color-border);transition:all var(--transition)}.step-dot.active{background:var(--color-primary);width:20px;border-radius:4px}.step-dot.done{background:var(--color-correct)}.rating-flash{position:fixed;top:50%;left:50%;transform:translate(-50%,-50%);padding:16px 32px;border-radius:var(--radius-lg);font-size:28px;font-weight:800;z-index:300;pointer-events:none;animation:flash-in .2s ease,flash-out .3s ease 1.2s forwards;box-shadow:var(--shadow-md)}.rating-flash.easy{background:#e8f5e9;color:#2e7d32}.rating-flash.good{background:#e3f2fd;color:#1565c0}.rating-flash.hard{background:#fff3e0;color:#e65100}.rating-flash.again{background:#fce4ec;color:#c62828}@keyframes flash-in{0%{opacity:0;transform:translate(-50%,-50%) scale(.8)}to{opacity:1;transform:translate(-50%,-50%) scale(1)}}@keyframes flash-out{0%{opacity:1}to{opacity:0}}@keyframes flash-correct{0%{border-color:var(--color-correct);background:#e8f5e9}to{border-color:var(--color-border);background:transparent}}@keyframes flash-wrong{0%{border-color:var(--color-incorrect);background:#fce4ec}to{border-color:var(--color-border);background:transparent}}.frame-flash-correct{animation:flash-correct .5s ease}.frame-flash-wrong{animation:flash-wrong .5s ease}.review-card-screen{display:flex;flex-direction:column;min-height:100vh;padding:0;background:var(--color-bg);position:relative}.review-progress{height:4px;background:var(--color-border)}.review-progress-fill{height:100%;background:var(--color-primary);transition:width .3s ease}.review-counter{text-align:right;padding:8px 16px 0;font-size:13px;color:var(--color-text-muted);font-weight:500}.review-prompt{padding:16px 16px 12px;background:var(--color-surface);border-bottom:1px solid var(--color-border)}.review-prompt-label{font-size:12px;font-weight:600;color:var(--color-text-muted);text-transform:uppercase;letter-spacing:.04em;margin-bottom:6px}.review-prompt-text{font-size:20px;font-weight:600;line-height:1.4;color:var(--color-text)}.review-frame{margin:16px;border:2px dashed var(--color-border);border-radius:var(--radius-lg);padding:16px;min-height:80px;display:flex;flex-direction:column;justify-content:center;transition:border-color .2s ease,background .2s ease}.review-frame-placeholder{text-align:center;color:var(--color-text-muted);font-size:14px;pointer-events:none}.review-frame-tiles{display:flex;flex-wrap:wrap;gap:8px;justify-content:center}.review-correct-answer{margin:0 16px 16px;padding:14px;background:#e8f5e9;border-radius:var(--radius-md);border:1.5px solid #a5d6a7}.review-pool{padding:12px 16px;display:flex;flex-wrap:wrap;gap:8px;justify-content:center;min-height:70px;border-top:1px solid var(--color-border);background:var(--color-surface-raised)}.review-actions{padding:12px 16px;display:flex;gap:8px;background:var(--color-surface);border-top:1px solid var(--color-border);padding-bottom:max(12px,env(safe-area-inset-bottom,12px))}.hint-btn{position:absolute;right:16px;bottom:80px;width:44px;height:44px;border-radius:50%;background:var(--color-target);color:#1a1200;border:none;font-size:20px;font-weight:800;cursor:pointer;box-shadow:var(--shadow-md);display:flex;align-items:center;justify-content:center;z-index:20}.hint-btn:disabled{opacity:.4}.hint-popup{position:absolute;right:68px;bottom:86px;background:var(--color-surface);border:1.5px solid var(--color-target);border-radius:var(--radius-md);padding:12px 14px;max-width:220px;box-shadow:var(--shadow-md);z-index:30;font-size:14px;line-height:1.5}.chunking-editor{display:flex;flex-wrap:wrap;gap:0;align-items:center;padding:8px 0}.chunk-group{display:inline-flex;align-items:center}.merge-btn{display:inline-flex;align-items:center;justify-content:center;width:28px;height:28px;border-radius:50%;background:var(--color-surface-raised);border:1.5px solid var(--color-border);cursor:pointer;color:var(--color-text-muted);transition:all var(--transition);flex-shrink:0;margin:0 2px}.merge-btn:hover{background:var(--color-primary);border-color:var(--color-primary);color:#fff}.tile-merged{position:relative}.split-icon{margin-left:6px;font-size:11px;opacity:.6}