:root{--bg-color: #F0F9FF;--card-bg: #FFFFFF;--primary: #4ECDC4;--primary-dark: #3DB8B0;--secondary: #FF8A65;--accent: #FFD93D;--text-main: #2C3E50;--text-light: #64748B;--danger: #EF4444;--success: #10B981}*{box-sizing:border-box;font-family:Quicksand,PingFang SC,system-ui,sans-serif}body{margin:0;padding:0;background-color:var(--bg-color);background-image:radial-gradient(#E0F2FE 2px,transparent 2px);background-size:30px 30px;display:flex;justify-content:center;align-items:center;min-height:100vh;color:var(--text-main)}.app-root{width:100%;max-width:480px;height:100vh;max-height:850px;display:flex;flex-direction:column;padding:16px}.cloud-bar{background:#ffffffe6;padding:8px 16px;border-radius:999px;font-size:13px;font-weight:700;color:var(--primary);display:flex;align-items:center;justify-content:center;gap:8px;margin-bottom:16px;box-shadow:0 4px 12px #0000000d;-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);flex-shrink:0}.pulse{animation:pulse 1.5s infinite}@keyframes pulse{0%,to{opacity:.5}50%{opacity:1}}.main-content{flex:1;background:var(--card-bg);border-radius:32px;box-shadow:0 12px 32px #00000014,0 4px 8px #0000000a;overflow:hidden;position:relative}.page-container{width:100%;height:100%;padding:24px;display:flex;flex-direction:column;overflow-y:auto}button{border:none;outline:none;cursor:pointer;font-family:inherit;border-radius:20px;font-weight:800;font-size:16px;transition:all .2s cubic-bezier(.68,-.55,.265,1.55);display:flex;align-items:center;justify-content:center;gap:8px;padding:16px}button:active:not(:disabled){transform:translateY(4px)}.btn-primary{background:var(--primary);color:#fff;box-shadow:0 6px 0 var(--primary-dark)}.btn-primary:active:not(:disabled){box-shadow:0 2px 0 var(--primary-dark)}.btn-secondary{background:#fff0ed;color:var(--secondary);box-shadow:0 6px #ffd0c2}.btn-secondary:active:not(:disabled){box-shadow:0 2px #ffd0c2}.btn-ai{background:#f3e8ff;color:#9333ea;box-shadow:0 6px #d8b4fe}.btn-ai:active:not(:disabled){box-shadow:0 2px #d8b4fe}.btn-ai:disabled{opacity:.7;cursor:wait}.icon-btn{background:#f1f5f9;padding:10px;border-radius:50%;box-shadow:0 4px #e2e8f0;color:var(--text-main)}.icon-btn:active{box-shadow:0 0 #e2e8f0}.start-page{align-items:center;justify-content:center;text-align:center}.hero-icon{background:#e0f2fe;padding:24px;border-radius:32px;margin-bottom:24px}.start-page h1{font-size:32px;margin:0 0 8px;color:var(--text-main)}.subtitle{color:var(--text-light);margin-bottom:40px;font-size:16px}.action-buttons{display:flex;flex-direction:column;gap:16px;width:100%}.header-bar{display:flex;justify-content:space-between;align-items:center;margin-bottom:24px}.mode-badge{background:#fef3c7;color:#d97706;padding:6px 12px;border-radius:999px;font-weight:700;font-size:14px}.score-badge{display:flex;align-items:center;gap:4px;font-size:18px;font-weight:900;background:#f8fafc;padding:6px 16px;border-radius:999px}.progress-container{margin-bottom:32px;position:relative}.progress-text{font-size:14px;color:var(--text-light);font-weight:700;margin-bottom:8px;text-align:right}.progress-bar-bg{height:12px;background:#f1f5f9;border-radius:999px;overflow:hidden}.progress-bar-fill{height:100%;background:var(--primary);border-radius:999px;transition:width .5s ease-out}.progress-deco{position:absolute;top:-10px;left:0;opacity:.5;pointer-events:none}.question-card{flex:1;display:flex;flex-direction:column;position:relative}.question-text{font-size:28px;font-weight:800;line-height:1.4;margin:0 0 40px;text-align:center}.options-grid{display:flex;flex-direction:column;gap:16px}.option-btn{background:#f8fafc;color:var(--text-main);border:2px solid #E2E8F0;box-shadow:0 4px #e2e8f0;font-size:20px;padding:20px;justify-content:flex-start}.option-btn:hover:not(:disabled){border-color:var(--primary);background:#f0fdfa}.option-btn.correct{background:#d1fae5;border-color:var(--success);color:#065f46;box-shadow:0 4px #34d399}.option-btn.wrong{background:#fee2e2;border-color:var(--danger);color:#991b1b;box-shadow:0 4px #f87171}.option-btn.disabled{opacity:.6;cursor:not-allowed}.feedback-overlay{position:absolute;top:40%;left:50%;transform:translate(-50%,-50%);z-index:10;background:#fff;padding:20px;border-radius:50%;box-shadow:0 10px 30px #00000026}.feedback-icon.check{color:var(--success)}.feedback-icon.cross{color:var(--danger)}.wrong-list-page h2{margin:0;font-size:24px}.empty-state{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;color:var(--text-light);font-weight:700}.wrong-items{display:flex;flex-direction:column;gap:16px;padding-bottom:80px}.wrong-item-card{background:#f8fafc;border:2px solid #E2E8F0;border-radius:24px;padding:20px}.wq-header{margin-bottom:12px}.wq-tag{background:#fee2e2;color:var(--danger);padding:4px 10px;border-radius:8px;font-size:12px;font-weight:700}.wq-question{font-size:18px;margin:0 0 16px;line-height:1.4}.wq-details p{margin:4px 0;font-size:14px;font-weight:700}.wq-wrong-ans span{color:var(--danger)}.wq-correct-ans span{color:var(--success)}.sticky-bottom{position:absolute;bottom:24px;left:24px;right:24px;width:calc(100% - 48px)}.summary-page{text-align:center}.summary-page h2{font-size:32px;color:var(--text-main);margin-bottom:32px}.stats-cards{display:flex;gap:16px;margin-bottom:40px}.stat-card{flex:1;background:#f1f5f9;padding:24px 16px;border-radius:24px}.stat-card.highlight{background:#fffbeb;border:2px solid var(--accent)}.stat-value{font-size:36px;font-weight:900;color:var(--text-main);margin-bottom:8px}.stat-value span{font-size:18px;color:var(--text-light)}.stat-card.highlight .stat-value{color:#d97706}.stat-label{font-size:14px;color:var(--text-light);font-weight:700}.chart-container{background:#f8fafc;padding:20px;border-radius:24px;margin-bottom:40px}.chart-container h3{margin:0 0 16px;font-size:16px;color:var(--text-light)}.learning-chart{width:100%;height:auto;overflow:visible}