.chemistry-half-app{max-width:900px;margin:30px auto;padding:0 16px;font-family:Arial,Helvetica,sans-serif}.half-header{margin-bottom:24px}.half-header h2{margin:0 0 8px;font-size:30px}.half-header p{margin:0;color:#555;line-height:1.5}.half-controls{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;margin-bottom:24px}.half-control{display:flex;flex-direction:column;gap:7px}.half-control label{font-weight:700}.half-control select{padding:10px 12px;border:1px solid #ccc;border-radius:7px;background:#fff;font-size:15px}.half-card{border:1px solid #ddd;border-radius:12px;padding:24px;background:#fff;box-shadow:0 2px 8px rgba(0,0,0,.06)}.half-meta{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:20px}.half-badge{padding:5px 10px;border-radius:999px;background:#f0f0f0;font-size:13px;font-weight:600;text-transform:capitalize}.half-question{font-size:19px;line-height:1.65;font-weight:600;margin-bottom:22px}.half-answer-area label{display:block;margin-bottom:8px;font-weight:700}.half-answer-area input{width:100%;box-sizing:border-box;padding:12px 14px;border:1px solid #bbb;border-radius:8px;font-family:inherit;font-size:17px}.half-hint{margin-top:7px;color:#666;font-size:13px}.half-buttons{display:flex;gap:10px;flex-wrap:wrap;margin-top:18px}.half-button{border:0;border-radius:8px;padding:11px 18px;cursor:pointer;font-size:15px;font-weight:700}.half-primary{background:#222;color:#fff}.half-secondary{background:#ececec;color:#222}.half-feedback{margin-top:20px;border-radius:10px;line-height:1.6}.half-correct,.half-incorrect,.half-info{padding:16px}.half-correct{background:#eaf7ee;border:1px solid #9fd4ae}.half-incorrect{background:#fff1f1;border:1px solid #e2aaaa}.half-info{background:#eef5ff;border:1px solid #aac8e8}.half-title{font-size:18px;font-weight:700;margin-bottom:10px}.half-working{margin-top:16px;padding-top:14px;border-top:1px solid rgba(0,0,0,.12)}.half-working-title{font-weight:700;margin-bottom:8px}@media(max-width:650px){.half-controls{grid-template-columns:1fr}.half-card{padding:18px}.half-buttons{flex-direction:column}.half-button{width:100%}}