.eng-chem-lab {font-family: system-ui, "Cairo", Tahoma, Arial; color:#0f172a}
.eng-chem-lab h2 {margin:16px 0 8px}
.eng-chem-lab h3 {margin:0 0 10px}
.eng-chem-lab .panel{background:#f8fafc;border:1px solid #e2e8f0;border-radius:14px;padding:16px;margin:14px 0}
.eng-chem-lab .grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
.eng-chem-lab label{display:block;font-size:13px;margin-bottom:6px;color:#334155}
.eng-chem-lab input, .eng-chem-lab select{width:100%;padding:10px;border:1px solid #cbd5e1;border-radius:10px;background:#fff}
.eng-chem-lab .actions{display:flex;flex-wrap:wrap;gap:8px;margin:12px 0}
.eng-chem-lab button{border:0;background:#0ea5e9;color:#fff;padding:10px 14px;border-radius:10px;cursor:pointer}
.eng-chem-lab button:hover{opacity:.9}
.eng-chem-lab .result{background:#fff;border:1px dashed #cbd5e1;border-radius:10px;padding:10px;margin-top:8px}
.eng-chem-lab .hint{font-size:12px;color:#64748b;margin-top:8px}
.eng-chem-lab .pt-mini{display:grid;grid-template-columns:repeat(10,36px);gap:6px;align-items:center}
.eng-chem-lab .el{width:36px;height:36px;border:1px solid #cbd5e1;border-radius:8px;display:flex;align-items:center;justify-content:center;background:#fff;cursor:pointer;font-weight:600}
.eng-chem-lab .el:hover{background:#e0f2fe}
@media (max-width:700px){.eng-chem-lab .grid{grid-template-columns:1fr}}