.chemistry-tools-back-titrations{--bg:#f4f7fb;--card:#fff;--ink:#172033;--muted:#657086;--line:#dbe3ef;--accent:#2857c5;--accent-soft:#eef3ff;--success:#16794b;--error:#9b2525;font-family:Arial,Helvetica,sans-serif;color:var(--ink);line-height:1.5}
.chemistry-tools-back-titrations,.chemistry-tools-back-titrations *{box-sizing:border-box}
.chemistry-tools-back-titrations .page{max-width:980px;margin:0 auto;padding:28px 18px 50px}
.chemistry-tools-back-titrations h1{margin:0 0 6px;font-size:clamp(28px,4vw,40px)}
.chemistry-tools-back-titrations .subtitle{color:var(--muted);margin:0 0 22px}
.chemistry-tools-back-titrations .card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:20px;box-shadow:0 4px 18px rgba(30,55,90,.05);margin-bottom:18px}
.chemistry-tools-back-titrations .toolbar{display:flex;gap:16px;flex-wrap:wrap;align-items:flex-end;justify-content:space-between}
.chemistry-tools-back-titrations .field{flex:1;min-width:220px}.chemistry-tools-back-titrations .question-field{max-width:310px}
.chemistry-tools-back-titrations label{display:block;font-weight:700;margin-bottom:6px}
.chemistry-tools-back-titrations input{width:100%;padding:11px 12px;border:1px solid #bcc8da;border-radius:9px;font-size:16px;background:#fff;color:var(--ink)}
.chemistry-tools-back-titrations input:focus{outline:3px solid rgba(40,87,197,.15);border-color:var(--accent)}
.chemistry-tools-back-titrations button{padding:12px 18px;border:0;border-radius:9px;background:var(--accent);color:#fff;font-size:16px;font-weight:700;cursor:pointer}
.chemistry-tools-back-titrations button.secondary{background:#fff;color:var(--accent);border:1px solid var(--accent)}
.chemistry-tools-back-titrations button:hover{filter:brightness(.96)}
.chemistry-tools-back-titrations .button-row{display:flex;gap:8px;flex-wrap:wrap}
.chemistry-tools-back-titrations .hint{color:var(--muted);font-size:13px;margin-top:6px}
.chemistry-tools-back-titrations .question-label{color:var(--muted);font-size:14px;font-weight:700;margin-bottom:8px;text-transform:uppercase;letter-spacing:.04em}
.chemistry-tools-back-titrations .question-text{font-size:18px;line-height:1.7}.chemistry-tools-back-titrations .question-text p{margin:0 0 14px}
.chemistry-tools-back-titrations .equation{padding:12px 14px;background:#f8faff;border-left:4px solid var(--accent);border-radius:7px;margin:12px 0;font-family:"Cambria Math","Times New Roman",serif;font-size:18px;overflow:auto}
.chemistry-tools-back-titrations .answer-area{margin-top:22px;padding-top:20px;border-top:1px solid var(--line)}
.chemistry-tools-back-titrations .answer-row{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:10px;align-items:end}
.chemistry-tools-back-titrations .answer-input-wrap{position:relative}.chemistry-tools-back-titrations .answer-input-wrap input{padding-right:42px}
.chemistry-tools-back-titrations .answer-unit{position:absolute;right:14px;top:50%;transform:translateY(-50%);font-weight:700;color:var(--muted)}
.chemistry-tools-back-titrations .feedback{display:none;margin-top:14px;padding:13px;border-radius:9px}
.chemistry-tools-back-titrations .feedback.good{display:block;background:#eefaf4;border:1px solid #ccebdc;color:var(--success)}
.chemistry-tools-back-titrations .feedback.bad{display:block;background:#fff2f2;border:1px solid #efc7c7;color:var(--error)}
.chemistry-tools-back-titrations .working-button{margin-top:14px}.chemistry-tools-back-titrations .working{margin-top:18px;padding-top:18px;border-top:1px solid var(--line)}
.chemistry-tools-back-titrations .working h3{margin:20px 0 8px;font-size:18px}.chemistry-tools-back-titrations .working h3:first-child{margin-top:0}
.chemistry-tools-back-titrations .calculation{background:#fbfcff;border:1px solid var(--line);border-radius:10px;padding:13px 14px;margin:9px 0;font-family:"Cambria Math","Times New Roman",serif;font-size:17px;overflow:auto}
.chemistry-tools-back-titrations .final-answer{background:#eefaf4;border:1px solid #ccebdc;color:var(--success);border-radius:10px;padding:14px;margin-top:16px;font-size:20px;font-weight:800}
@media(max-width:720px){.chemistry-tools-back-titrations .answer-row{grid-template-columns:1fr}.chemistry-tools-back-titrations .answer-row button{width:100%}.chemistry-tools-back-titrations .button-row{width:100%}.chemistry-tools-back-titrations .button-row button{flex:1 1 140px}}