/* IntoChemistry v13.3: all styling is scoped to the quality feature. */
.icv13-quality,.icv13-quality-lesson,.icv13-quality-hub{--icnavy:#102f53;--icblue:#0e6bc6;--icline:#d5e6f0;--icink:#173d55;max-width:1430px;margin:24px auto 55px;color:var(--icink);font:inherit;line-height:1.58}.icv13-quality *,.icv13-quality-lesson *,.icv13-quality-hub *{box-sizing:border-box;min-width:0}.icv13-quality h2,.icv13-quality h3,.icv13-quality h4,.icv13-quality-lesson h1,.icv13-quality-lesson h2,.icv13-quality-hub h2{color:var(--icnavy);line-height:1.2}.icv13-quality-eyebrow{font-size:.78rem;font-weight:850;letter-spacing:.07em;color:#146f95;text-transform:uppercase}.icv13-quality-hero{background:linear-gradient(110deg,#eaf6fc,#f9fcfe);border:1px solid #cee3f0;border-radius:17px;padding:29px clamp(20px,4vw,48px);display:grid;grid-template-columns:minmax(0,1fr) 290px;align-items:center;gap:25px}.icv13-quality-hero h2{font:700 clamp(1.9rem,3.3vw,2.9rem)/1.15 Georgia,serif;margin:4px 0 14px}.icv13-quality-hero p{max-width:850px;margin:0 0 13px}.icv13-quality-hero img{width:100%;height:auto}.icv13-quality-pills{display:flex;gap:9px;flex-wrap:wrap}.icv13-quality-pills span{background:#d8eaf8;color:#0b537b;border-radius:35px;padding:5px 13px;font-weight:800;font-size:.75rem}.icv13-quality-grid{display:grid;grid-template-columns:minmax(0,3.15fr) minmax(235px,1fr);gap:21px;margin-top:20px}.icv13-quality-main,.icv13-quality-rail section{background:#fff;border:1px solid var(--icline);border-radius:12px;box-shadow:0 5px 20px #16355209;overflow:hidden}.icv13-quality-toolbar{display:flex;align-items:end;justify-content:space-between;gap:12px;background:#f4f9fd;border-bottom:1px solid var(--icline);padding:18px 24px}.icv13-quality-toolbar label{display:block;font-size:.8rem;font-weight:850;margin-bottom:5px}.icv13-quality-toolbar select{background:#fff;border:1px solid #aac8d9;border-radius:7px;padding:10px;min-height:43px;max-width:100%;color:#143858}.icv13-quality button{font-family:inherit;cursor:pointer;border-radius:8px;font-weight:800}.icv13-quality-next,.icv13-quality-check-button{background:#1264bd;color:#fff;border:1px solid #1264bd;padding:10px 17px;min-height:43px}.icv13-quality-next:hover,.icv13-quality-check-button:hover{background:#0d4e9c}.icv13-quality-work{padding:25px}.icv13-quality-work>h3{font:700 clamp(1.3rem,2.4vw,1.75rem)/1.2 Georgia,serif;margin:4px 0}.icv13-quality-context{margin:8px 0 14px}.icv13-quality-formula{border-left:4px solid #177ec0;background:#ebf6fd;border-radius:7px;padding:13px;overflow-wrap:anywhere}.icv13-quality-figure,.icv13-quality-scatter{display:block;width:100%;height:auto;border:1px solid #dcecf3;border-radius:11px;margin:15px 0;background:#f7fbfd}.icv13-quality-meter{display:flex;align-items:center;gap:17px;margin:18px 0;font-size:.8rem}.icv13-quality-meter-track{height:10px;border-radius:9px;background:#e0ecf3;flex:1;overflow:hidden}.icv13-quality-meter-track>span{display:block;height:100%;background:#158b84;transition:width .2s ease}.icv13-quality-steps{padding:0;margin:14px 0;list-style:none;display:grid;gap:13px}.icv13-quality-step{padding:16px 18px;border:1px solid #d8e6ec;border-radius:10px;background:#fcfdfe}.icv13-quality-step.done{background:#f1fbf5;border-color:#c2e0d1}.icv13-quality-step.locked{background:#f3f7fa;color:#25465d}.icv13-quality-step h4{margin:0 0 7px;font-size:1.03rem}.icv13-quality-step p{margin:5px 0 10px}.icv13-quality-form label{display:block;font-size:.83rem;font-weight:800;margin:10px 0 5px}.icv13-quality-field{display:flex;align-items:center;gap:11px;flex-wrap:wrap}.icv13-quality-field input{font:inherit;border:1px solid #a4bfce;border-radius:8px;padding:10px;max-width:310px;width:100%;min-height:42px;background:#fff;color:#102f53}.icv13-quality-hint-button,.icv13-quality-reveal{border:1px solid #bdd6e7;background:#eff8fd;color:#0b5685;padding:10px 13px;margin:5px 0 5px 8px}.icv13-quality-hint{background:#fef9ec;border-radius:7px;padding:12px}.icv13-quality-feedback.incorrect{color:#a83236;font-weight:750}.icv13-quality-success{color:#12634f;background:#e6f7ee;padding:13px;border-radius:8px;font-weight:800}.icv13-quality-answer{font-weight:850;color:#126852}.icv13-quality-explanation{font-size:.87rem;color:#406477}.icv13-quality-rail{display:grid;gap:15px;align-content:start}.icv13-quality-rail section{padding:18px}.icv13-quality-rail h3{font:700 1.15rem Georgia,serif;margin:0 0 10px}.icv13-quality-rail ol{padding-left:21px}.icv13-quality-rail li{margin-bottom:8px;font-size:.86rem}.icv13-quality-download{padding:10px 0;border-top:1px solid #e0edf1}.icv13-quality-download strong{display:block;font-size:.87rem;color:#153e5b}.icv13-quality-download a{display:inline-block;background:#eef7fc;color:#145e8a;font-size:.76rem;font-weight:800;text-decoration:none;margin:6px 4px 0 0;padding:6px 9px;border-radius:5px}
.icv13-quality-hub>header,.icv13-quality-lesson-hero{background:linear-gradient(105deg,#eaf5fc,#f7fbff);border:1px solid #d3e7f0;border-radius:13px;padding:31px clamp(20px,4vw,45px)}.icv13-quality-hub h2{font:700 clamp(1.8rem,3vw,2.7rem) Georgia,serif;margin:6px 0}.icv13-quality-hub-cards{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px;margin:23px 0}.icv13-quality-hub-cards article{border:1px solid #d6e5ed;border-radius:13px;background:#fff;padding:15px 20px 23px}.icv13-quality-hub-cards img{width:100%;aspect-ratio:2.5/1;object-fit:contain;background:#f5fafc;border-radius:8px}.icv13-quality-hub-cards h3{font-size:1.25rem;color:#123858;margin:12px 0 6px}.icv13-quality-hub-cards p{color:#44677f;font-size:.9rem}.icv13-quality-hub-cards a{color:#0f699c;font-weight:800}.icv13-quality-muted{font-size:.8rem;color:#58718a}.icv13-quality-hub-foot{background:#eaf8f1;border-radius:10px;padding:15px 20px;color:#185f4b}
.icv13-quality-lesson-hero h1{font:700 clamp(2rem,3.4vw,3rem) Georgia,serif;margin:5px 0}.icv13-quality-lesson-grid{display:grid;grid-template-columns:minmax(170px,.9fr) minmax(0,3fr) minmax(220px,1.15fr);gap:20px;align-items:start;margin-top:23px}.icv13-quality-lesson-grid nav,.icv13-quality-lesson-grid aside section{border:1px solid #d5e7ee;border-radius:11px;background:#f8fbfd;padding:17px}.icv13-quality-lesson-grid nav{position:sticky;top:20px}.icv13-quality-lesson-grid nav h3,.icv13-quality-lesson-grid aside h3{font:700 1.16rem Georgia,serif;margin:0 0 9px;color:#14395c}.icv13-quality-lesson-grid nav ol{margin:0;padding-left:20px}.icv13-quality-lesson-grid nav li{margin:8px 0;font-size:.83rem}.icv13-quality-lesson-grid nav a,.icv13-quality-lesson-grid aside a{color:#0f6890}.icv13-quality-lesson-body h2{font:700 clamp(1.3rem,2vw,1.65rem) Georgia,serif;margin:0 0 10px}.icv13-quality-lesson-body section{margin:0 0 25px}.icv13-quality-lesson-body p{margin:0 0 11px}.icv13-quality-lesson-body figure{margin:17px 0;border:1px solid #d5e7ee;background:#f7fcfe;border-radius:11px;padding:9px}.icv13-quality-lesson-body img{width:100%;height:auto}.icv13-quality-lesson-body figcaption{color:#4e6a80;font-size:.76rem}.icv13-quality-goal{background:#eaf7fc;border-left:4px solid #147abd;padding:16px 19px;margin-bottom:21px}.icv13-quality-lesson-grid aside{display:grid;gap:16px}.icv13-quality-lesson-grid aside li{margin:8px 0;font-size:.84rem}.icv13-quality-lesson-grid aside ul{padding-left:19px}.icv13-quality-lesson-grid aside a{display:block;background:#e7f4fb;margin:7px 0;border-radius:7px;padding:8px 11px;text-decoration:none;font-weight:850;font-size:.83rem}.icv13-quality-check{background:#eef8f4;border-radius:10px;padding:18px}.icv13-quality-check details{background:white;padding:12px;margin-top:13px}.icv13-quality-check summary{cursor:pointer;font-weight:800;color:#0c7366}
@media(max-width:1050px){.icv13-quality-grid{grid-template-columns:1fr}.icv13-quality-rail{grid-template-columns:repeat(2,minmax(0,1fr))}.icv13-quality-lesson-grid{grid-template-columns:minmax(170px,1fr) minmax(0,3fr)}.icv13-quality-lesson-grid aside{grid-column:2;grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:700px){.icv13-quality-hero{display:block;padding:24px 18px}.icv13-quality-hero img{display:none}.icv13-quality-toolbar{display:block;padding:16px}.icv13-quality-toolbar>button{margin-top:12px}.icv13-quality-work{padding:16px}.icv13-quality-rail{grid-template-columns:1fr}.icv13-quality-meter{display:block}.icv13-quality-meter-track{margin-top:8px}.icv13-quality-hub-cards{grid-template-columns:1fr}.icv13-quality-lesson-grid{grid-template-columns:1fr}.icv13-quality-lesson-grid nav{position:static}.icv13-quality-lesson-grid aside{grid-column:auto;grid-template-columns:1fr}}
@media(prefers-reduced-motion:reduce){.icv13-quality-meter-track>span{transition:none}}

/* v13.20 accessibility: discoverable keyboard focus, nonfaded explanatory content, readable data equivalent. */
.icv13-quality :focus-visible{outline:3px solid #155c9a;outline-offset:3px}
.icv13-quality button,.icv13-quality select{min-height:44px}
.icv13-quality-step .icv13-quality-locked{color:#304d62}
.icv13-quality-calibration-data{margin:12px 0 18px;padding:11px;border:1px solid #acc7d8;border-radius:9px;background:#f8fcff}
.icv13-quality-calibration-data summary{cursor:pointer;font-weight:750;color:#164e70;min-height:44px;display:list-item;padding:10px}
.icv13-quality-calibration-data table{border-collapse:collapse;width:100%;font-size:.95rem}
.icv13-quality-calibration-data th,.icv13-quality-calibration-data td{padding:7px;border:1px solid #aac8d7;text-align:left}
.icv13-quality-calibration-data th{background:#e6f2f7;color:#1b3f57}
.icv13-quality-calibration-data caption{text-align:left;padding:6px;font-weight:700}
.icv13-quality-solution-title,.icv13-quality-current-title{scroll-margin-top:5rem}
@media(max-width:450px){.icv13-quality-calibration-data{overflow-x:auto}}