.icv13-lab{--navy:#123354;--blue:#126991;--teal:#0c8b8b;--surface:#f5f9fc;--line:#d6e5ec;--text:#17374c;max-width:1320px;margin:25px auto 45px;color:var(--text);font-family:inherit;font-size:16px;line-height:1.58}
.icv13-lab *{box-sizing:border-box}.icv13-lab input,.icv13-lab button,.icv13-lab select{font:inherit}.icv13-lab :focus-visible{outline:3px solid #1997b9;outline-offset:3px}
.icv13-lab-hero{display:grid;grid-template-columns:minmax(0,1fr) 340px;align-items:center;gap:30px;padding:34px clamp(22px,4vw,54px);background:linear-gradient(110deg,#113150,#185f7c);color:#fff;border-radius:18px;overflow:hidden}
.icv13-lab-hero h2{color:#fff;font-size:clamp(1.9rem,3vw,2.75rem);margin:8px 0 13px;line-height:1.15;font-weight:850;letter-spacing:-.03em}.icv13-lab-hero p{max-width:680px;color:#dff0f7;margin:0}.icv13-lab-hero img{display:block;width:100%;height:auto;max-height:230px;object-fit:contain;border-radius:13px}
.icv13-lab-kicker{display:block;font-size:.73rem;letter-spacing:.10em;text-transform:uppercase;font-weight:800;color:#14718c}.icv13-lab-hero .icv13-lab-kicker{color:#85dfe7}
.icv13-lab-chips{display:flex;gap:8px;flex-wrap:wrap;margin-top:19px}.icv13-lab-chips span{font-size:.76rem;font-weight:700;border:1px solid #ffffff61;border-radius:60px;padding:4px 10px}
.icv13-lab-grid{display:grid;grid-template-columns:minmax(0,2.1fr) minmax(270px,.8fr);align-items:start;gap:22px;margin-top:24px}.icv13-lab-main,.icv13-lab-panel{background:white;border:1px solid var(--line);border-radius:14px;box-shadow:0 8px 27px #112d4908;min-width:0}
.icv13-lab-bar{display:flex;justify-content:space-between;align-items:flex-end;gap:18px;padding:21px 26px;background:#f0f7fa;border-radius:14px 14px 0 0;border-bottom:1px solid var(--line)}.icv13-lab-bar>div{flex:1}.icv13-lab-bar label{display:block;font-weight:800;font-size:.82rem;margin-bottom:5px;color:var(--navy)}
.icv13-lab-bar select{width:100%;min-height:46px;padding:10px 13px;border-radius:9px;background:#fff;border:1px solid #adc8d6;color:var(--navy)}.icv13-lab-new,.icv13-lab-check{border:0;border-radius:9px;background:#0b7093;color:#fff!important;padding:11px 17px;font-weight:800;min-height:44px;cursor:pointer}.icv13-lab-new:hover,.icv13-lab-check:hover{background:#075570}
.icv13-lab-work{padding:clamp(20px,3vw,34px)}.icv13-lab-title{font-size:clamp(1.36rem,2.4vw,1.85rem);letter-spacing:-.015em;color:var(--navy);font-weight:850;margin:6px 0 7px}.icv13-lab-context{font-size:.98rem;margin:0 0 14px}.icv13-lab-formula{padding:13px 15px;background:#e6f2f9;color:#165a81;border:1px solid #c9e2f0;border-radius:9px;text-align:center;font-size:1.09rem;font-weight:800;margin-bottom:18px}
.icv13-lab-illustration{display:block;width:100%;max-height:295px;object-fit:contain;height:auto;padding:7px;border:1px solid #d3e7ef;border-radius:12px;background:#f8fcfd}.icv13-lab-progress{display:flex;gap:12px;align-items:center;justify-content:space-between;margin:18px 0;font-size:.83rem;color:#175570}.icv13-lab-progress-track{width:45%;height:9px;border-radius:20px;background:#deebf0;overflow:hidden}.icv13-lab-progress-track span{display:block;height:100%;background:linear-gradient(90deg,#148bb1,#21aa99)}
.icv13-lab-steps{list-style:none;padding:0;margin:0}.icv13-lab-step{padding:18px;border:1px solid #dae7ed;border-radius:12px;margin:11px 0;background:#fff}.icv13-lab-step.is-complete{border-left:4px solid #0c9b87;background:#f3fcf9}.icv13-lab-step.is-locked{background:#f8fafb;opacity:.74}.icv13-lab-step-heading{display:flex;gap:12px;align-items:center}.icv13-lab-step-heading h4{font-size:.98rem;font-weight:820;margin:0;color:var(--navy)}.icv13-lab-number{background:#e0f0f6;color:#0b6286;width:34px;height:34px;flex:none;border-radius:9px;display:grid;place-items:center;font-weight:820}.icv13-lab-step>p{margin:7px 0 0 46px;font-size:.88rem}
.icv13-lab-form{margin:13px 0 0 46px}.icv13-lab-form label{display:block;font-size:.81rem;font-weight:750}.icv13-lab-entry{display:flex;max-width:440px;margin:6px 0 10px;min-width:0}.icv13-lab-entry input{min-width:0;width:65%;padding:10px 12px;border:1px solid #aac9d6;border-radius:8px 0 0 8px;min-height:44px;color:#142f42;background:#fff}.icv13-lab-entry span{flex:1;background:#eaf4f8;border:1px solid #aac9d6;border-left:0;border-radius:0 8px 8px 0;display:flex;align-items:center;padding:8px;color:#30556a;font-size:.8rem;overflow-wrap:anywhere}
.icv13-lab-hint-toggle,.icv13-lab-show{cursor:pointer;border:1px solid #b5ced9;background:#fff;color:#12627f;padding:10px 14px;border-radius:9px;min-height:44px;font-size:.87rem;font-weight:800;margin-left:6px}.icv13-lab-hint{padding:10px 13px;background:#fff8e6;border-left:3px solid #d7a53e;font-size:.86rem}.icv13-lab-feedback{font-size:.84rem;color:#a0482e;min-height:18px}.icv13-lab-solution{color:#0b7a64;font-weight:800}.icv13-lab-reason{color:#405f70}.icv13-lab-actions{display:flex;align-items:center;gap:13px;margin:21px 0}.icv13-lab-success{color:#0a7964;font-weight:750;font-size:.85rem}.icv13-lab-method{margin-top:20px;padding:12px 14px;background:#f0f5f8;border-radius:9px;color:#416174;font-size:.82rem}
.icv13-lab-rail{display:grid;gap:16px}.icv13-lab-panel{padding:22px}.icv13-lab-panel h3{font-size:1.05rem;font-weight:840;color:var(--navy);margin:0 0 9px}.icv13-lab-panel p,.icv13-lab-panel li{font-size:.86rem;color:#446276}.icv13-lab-panel ol{padding-left:21px;margin:0}.icv13-lab-related{display:block;background:#edf6fa;padding:8px 10px;border-radius:8px;margin-top:7px;color:#0b6485;text-decoration:none;font-weight:740;font-size:.85rem}.icv13-lab-related:hover{text-decoration:underline}
.icv13-lab-download{padding:11px 0;border-bottom:1px solid #e0eaf0}.icv13-lab-download strong{color:#173b56;font-size:.85rem}.icv13-lab-download div{display:flex;gap:6px;flex-wrap:wrap;margin-top:7px}.icv13-lab-download a{font-size:.76rem;padding:4px 8px;border:1px solid #c6dfe8;border-radius:7px;text-decoration:none;color:#116584;font-weight:750}.icv13-lab-download a:hover{background:#e7f5f9}.icv13-lab-note{color:#688295;font-size:.78rem!important}
@media(max-width:1000px){.icv13-lab-grid{grid-template-columns:1fr}.icv13-lab-rail{grid-template-columns:repeat(2,minmax(0,1fr))}.icv13-lab-hero{grid-template-columns:1fr 250px}}
@media(max-width:670px){.icv13-lab{margin:15px auto}.icv13-lab-hero{display:block;padding:26px 18px}.icv13-lab-hero img{display:none}.icv13-lab-grid{gap:12px}.icv13-lab-rail{grid-template-columns:1fr}.icv13-lab-work{padding:15px}.icv13-lab-bar{flex-direction:column;align-items:stretch;padding:17px}.icv13-lab-bar>div{width:100%}.icv13-lab-step{padding:12px}.icv13-lab-step>p,.icv13-lab-form{margin-left:0}.icv13-lab-progress{flex-direction:column;align-items:stretch}.icv13-lab-progress-track{width:100%}.icv13-lab-hint-toggle{margin-left:0;margin-top:6px}}
@media(prefers-reduced-motion:reduce){.icv13-lab *{transition:none!important;scroll-behavior:auto!important}}
/* Lesson structure aligns with the established IntoChemistry instructional design. */
.icv13-lab-lesson{--line:#d6e5ec;max-width:1400px;margin:25px auto 55px;font-family:inherit;color:#16364d;line-height:1.65}.icv13-lab-lesson *{box-sizing:border-box}.icv13-lesson-hero{padding:33px clamp(21px,5vw,63px);border-radius:15px;background:linear-gradient(95deg,#eaf5fc 0%,#f7fbff 65%,#d7edf6 100%);border:1px solid #d3e8f3}.icv13-lesson-hero h1{font-size:clamp(2rem,3.8vw,3.3rem);font-family:Georgia,serif;color:#112e54;margin:3px 0 8px;line-height:1.18}.icv13-lesson-hero>p:last-child{font-size:1.05rem;color:#285b77;max-width:800px;margin:0}
.icv13-lesson-grid{display:grid;grid-template-columns:minmax(184px,.84fr) minmax(0,3fr) minmax(225px,1fr);gap:23px;margin-top:23px;align-items:start}.icv13-lesson-toc,.icv13-lesson-side section{border:1px solid var(--line);border-radius:12px;background:#f8fbfd;padding:20px;box-shadow:0 4px 18px #0e2e4708}.icv13-lesson-toc{position:sticky;top:22px}.icv13-lesson-toc strong{color:#123354;font-family:Georgia,serif;font-size:1.13rem}.icv13-lesson-toc ol{padding-left:20px;margin:14px 0 0}.icv13-lesson-toc li{padding:5px 0;font-size:.85rem}.icv13-lesson-toc a{color:#126a92;text-decoration:none}.icv13-lesson-toc a:hover{text-decoration:underline}
.icv13-lesson-main section{margin-bottom:27px}.icv13-lesson-main h2{font-size:clamp(1.26rem,2.4vw,1.75rem);font-family:Georgia,serif;line-height:1.25;color:#123354;margin:0 0 10px}.icv13-lesson-main p{margin:0 0 12px}.icv13-lesson-goal{padding:17px 20px;border:1px solid #b7d9e8;background:#edf8fd;border-radius:11px;margin-bottom:24px}.icv13-lesson-goal strong{display:block;color:#125b82;font-weight:850}.icv13-lesson-goal p{margin:4px 0 0}
.icv13-lesson-figure{padding:9px 9px 12px;margin:19px 0 0;border:1px solid #d6e6ed;border-radius:12px;background:#f7fbfd}.icv13-lesson-figure img{display:block;width:100%;height:auto;border-radius:8px}.icv13-lesson-figure figcaption{font-size:.75rem;color:#587184;padding:5px 8px}.icv13-lesson-check{background:#eff9f3;border:1px solid #badfc9;border-radius:12px;padding:20px}.icv13-lesson-check details{margin-top:12px}.icv13-lesson-check summary{cursor:pointer;font-weight:800;color:#087667}.icv13-lesson-check details p{padding:12px;border-radius:7px;background:#fff}
.icv13-lesson-side{display:grid;gap:16px}.icv13-lesson-side section{padding:18px}.icv13-lesson-side h3{font-family:Georgia,serif;font-size:1.1rem;color:#123354;margin:0 0 8px}.icv13-lesson-side li,.icv13-lesson-side p{font-size:.84rem;color:#406477}.icv13-lesson-side ul{padding-left:19px;margin:7px 0}.icv13-lesson-side a{display:block;color:#126387;background:#eaf5f9;border-radius:8px;font-size:.83rem;font-weight:800;text-decoration:none;padding:8px 11px;margin:7px 0}.icv13-lesson-side a:hover{text-decoration:underline}.icv13-lesson-next{border-top:1px solid #d8e6ed;padding-top:12px;margin:12px 0 0}
@media(max-width:1100px){.icv13-lesson-grid{grid-template-columns:minmax(170px,1fr) minmax(0,3fr)}.icv13-lesson-side{grid-column:2;grid-template-columns:repeat(2,minmax(0,1fr))}}@media(max-width:700px){.icv13-lesson-grid{grid-template-columns:1fr}.icv13-lesson-toc{position:static}.icv13-lesson-side{grid-column:auto;grid-template-columns:1fr}.icv13-lesson-hero{padding:25px 19px}}
.icv13-lab-hub{max-width:1350px;margin:25px auto 50px;color:#12354d;font-family:inherit}.icv13-lab-hub *{box-sizing:border-box}.icv13-lab-hub-hero{background:linear-gradient(110deg,#eaf5fc,#f8fcfd);border:1px solid #d1e6f0;border-radius:16px;padding:32px clamp(20px,4vw,48px)}.icv13-lab-hub-hero h2{font-family:Georgia,serif;color:#113456;font-size:clamp(1.9rem,3vw,2.7rem);line-height:1.2;margin:7px 0}.icv13-lab-hub-hero p{font-size:1.05rem;color:#315f75;max-width:780px;margin:0}.icv13-lab-hub-cards{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:19px;margin-top:24px}.icv13-lab-hub-card{overflow:hidden;border-radius:14px;border:1px solid #d4e3ec;background:white;box-shadow:0 6px 24px #112e4710}.icv13-lab-hub-card img{width:100%;aspect-ratio:2.45/1;object-fit:contain;background:#eef8fb;padding:9px;display:block}.icv13-lab-hub-card>div{padding:20px 23px 23px}.icv13-lab-hub-card h3{font-size:1.2rem;color:#113556;margin:0 0 7px}.icv13-lab-hub-card p{color:#527084;font-size:.89rem;line-height:1.55;margin:0 0 16px}.icv13-lab-hub-card a{display:inline-block;color:#0d6890;background:#e9f6fa;border-radius:8px;padding:8px 13px;font-weight:800;text-decoration:none}.icv13-lab-hub-card a:hover{text-decoration:underline}.icv13-lab-unavailable{color:#536d7a;font-size:.8rem;font-weight:700}.icv13-lab-hub-footer{padding:18px 20px;border-radius:12px;margin-top:20px;background:#edf8f5;color:#175b58;font-size:.9rem}
@media(max-width:660px){.icv13-lab-hub-cards{grid-template-columns:1fr}.icv13-lab-hub-hero{padding:25px 20px}}