:root{--color-bg: #f5f6fb;--color-surface: #ffffff;--color-text: #1f2333;--color-muted: #6b7280;--color-primary: #4f46e5;--color-primary-dark: #4338ca;--color-success: #16a34a;--color-danger: #dc2626;--color-border: #e5e7eb;--radius: 14px;color-scheme:light}*{box-sizing:border-box}html,body,#root{height:100%}body{margin:0;background:var(--color-bg);color:var(--color-text);font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;-webkit-tap-highlight-color:transparent}button{font-family:inherit}.screen{max-width:640px;margin:0 auto;padding:16px 16px 40px;min-height:100%;display:flex;flex-direction:column;gap:16px}.app-header h1{font-size:1.5rem;margin:0 0 4px}.subtitle{color:var(--color-muted);margin:0}.app-header-nav{display:flex;align-items:center;justify-content:space-between;gap:8px}.app-header-nav h1{font-size:1.1rem;flex:1;text-align:center;margin:0}.btn{border:none;border-radius:var(--radius);padding:14px 18px;font-size:1rem;font-weight:600;cursor:pointer;min-height:48px}.btn-primary{background:var(--color-primary);color:#fff}.btn-primary:active{background:var(--color-primary-dark)}.btn-secondary{background:var(--color-surface);color:var(--color-text);border:1px solid var(--color-border)}.btn-success{background:var(--color-success);color:#fff}.btn-fail{background:var(--color-danger);color:#fff}.btn-block{width:100%}.btn:disabled{opacity:.45;cursor:not-allowed}.btn-icon{background:transparent;border:none;color:var(--color-primary);font-weight:600;padding:8px;cursor:pointer;min-height:40px}.btn-danger{color:var(--color-danger)}.dropzone{border:2px dashed var(--color-border);border-radius:var(--radius);padding:32px 16px;text-align:center;color:var(--color-muted);background:var(--color-surface);cursor:pointer}.dropzone.is-active{border-color:var(--color-primary);color:var(--color-primary)}.upload-messages{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:6px}.upload-messages li{padding:10px 12px;border-radius:10px;font-size:.9rem}.msg-info{background:#eef2ff;color:var(--color-primary-dark)}.msg-error{background:#fee2e2;color:var(--color-danger)}.section-header{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:4px 8px}.section-header h2{font-size:1.1rem;margin:0}.section-header .btn-icon{white-space:nowrap;font-size:.85rem}.empty-state{color:var(--color-muted);text-align:center;padding:24px 0}.deck-list ul{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:10px}.deck-row{background:var(--color-surface);border-radius:var(--radius);border:1px solid var(--color-border);padding:12px 14px;display:flex;align-items:center;gap:8px}.deck-row-main{flex:1;min-width:0;display:flex;flex-direction:column;gap:2px;cursor:pointer}.deck-name{font-weight:600;font-size:1.05rem;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.deck-name-input{font-weight:600;font-size:1.05rem;padding:4px 6px;border-radius:8px;border:1px solid var(--color-border)}.deck-summary{font-size:.82rem;color:var(--color-muted)}.deck-row-actions{display:flex;flex-direction:column;gap:4px;align-items:flex-end}.stats-bar{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;background:var(--color-surface);border-radius:var(--radius);padding:12px;border:1px solid var(--color-border)}.stat{display:flex;flex-direction:column;align-items:center;gap:2px}.stat-value{font-size:1.3rem;font-weight:700}.stat-label{font-size:.72rem;color:var(--color-muted);text-align:center}.stat-mastered .stat-value{color:var(--color-success)}.stat-new .stat-value{color:var(--color-primary)}.toggle-row{display:flex;align-items:center;gap:10px;font-size:.95rem;padding:6px 2px}.toggle-row input{width:20px;height:20px}.mode-grid{display:flex;flex-direction:column;gap:12px}.btn-mode{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius);padding:16px;text-align:left;display:flex;flex-direction:column;gap:4px;cursor:pointer}.mode-title{font-size:1.1rem;font-weight:700}.mode-desc{font-size:.85rem;color:var(--color-muted)}.reset-deck-btn{align-self:center;margin-top:auto}.mode-screen{flex:1}.progress-indicator{font-size:.85rem;color:var(--color-muted);white-space:nowrap}.flashcard{perspective:1200px;flex:1;min-height:320px;cursor:pointer}.flashcard-inner{position:relative;width:100%;height:100%;min-height:320px;transition:transform .5s;transform-style:preserve-3d}.flashcard.is-flipped .flashcard-inner{transform:rotateY(180deg)}.flashcard-face{position:absolute;top:0;right:0;bottom:0;left:0;backface-visibility:hidden;border-radius:var(--radius);background:var(--color-surface);border:1px solid var(--color-border);padding:24px;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;gap:12px}.flashcard-back{transform:rotateY(180deg);background:#eef2ff}.card-category{font-size:.75rem;text-transform:uppercase;letter-spacing:.04em;color:var(--color-primary);font-weight:700}.card-text{font-size:1.15rem;line-height:1.5;margin:0;white-space:pre-wrap}.keyword-chips{display:flex;flex-wrap:wrap;gap:6px;justify-content:center}.chip{background:#eef2ff;color:var(--color-primary-dark);border-radius:999px;padding:4px 10px;font-size:.75rem}.flashcard-back .chip{background:#e0e7ff}.flip-hint{font-size:.75rem;color:var(--color-muted);margin-top:auto}.nav-row{display:flex;gap:10px}.nav-row .btn{flex:1}.learn-card{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius);padding:20px;display:flex;flex-direction:column;gap:14px;flex:1}.answer-input{width:100%;border-radius:10px;border:1px solid var(--color-border);padding:12px;font-size:1rem;font-family:inherit;resize:vertical;margin-bottom:12px}.answer-compare{display:flex;flex-direction:column;gap:12px}.answer-col{background:var(--color-bg);border-radius:10px;padding:12px}.answer-col h3{margin:0 0 6px;font-size:.8rem;color:var(--color-muted);text-transform:uppercase}.answer-col p{margin:0;white-space:pre-wrap}.test-card{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius);padding:20px;display:flex;flex-direction:column;gap:16px}.option-list{display:flex;flex-direction:column;gap:10px}.option-btn{display:flex;align-items:center;gap:10px;text-align:left;padding:14px;border-radius:12px;border:1px solid var(--color-border);background:var(--color-bg);font-size:1rem;cursor:pointer;min-height:48px}.option-letter{display:inline-flex;align-items:center;justify-content:center;width:26px;height:26px;border-radius:50%;background:var(--color-border);font-weight:700;font-size:.85rem;flex-shrink:0}.option-btn.option-correct{background:#dcfce7;border-color:var(--color-success)}.option-btn.option-incorrect{background:#fee2e2;border-color:var(--color-danger)}.test-score{font-size:1.3rem;font-weight:700}.missed-list{display:flex;flex-direction:column;gap:12px}.missed-item{background:var(--color-surface);border:1px solid var(--color-border);border-radius:12px;padding:14px}.missed-answer{margin:4px 0 0;font-size:.9rem}.missed-correct{color:var(--color-success)}@media (min-width: 640px){.stats-bar{padding:16px}.nav-row{gap:16px}}