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