.lab-heading{padding:55px 0 22px}.lab-heading .eyebrow{margin-bottom:17px}.lab-heading h1{font-size:48px;letter-spacing:-1.8px;margin-bottom:18px}.lab-heading>p:last-child{font-size:14px;color:var(--muted)}.mode-picker{display:flex;gap:8px;padding:6px;background:#e6e8ee;border-radius:12px;width:fit-content}.mode-picker button{padding:11px 20px;border:1px solid transparent;border-radius:8px;background:transparent;color:#424b60;font-size:13px;font-weight:600}.mode-picker button[aria-pressed=true]{background:#fff;color:var(--blue);border-color:#bdc6eb;box-shadow:0 2px 6px #1f345010}.mode-help{font-size:12px;background:#edf0fb;color:#394978;padding:13px 18px;border-left:3px solid var(--blue);margin:20px 0 28px}.lab-workspace{display:grid;grid-template-columns:minmax(0,1fr) 295px;border:1px solid var(--line);border-radius:18px;overflow:hidden;background:#fff}.image-workspace{padding:25px;min-width:0}.photo-heading{display:flex;align-items:center;justify-content:space-between;margin-bottom:18px}.photo-heading h2{font-size:21px}.photo-heading>span{font:12px monospace;color:var(--muted)}.comparison{position:relative;aspect-ratio:4/3;background:#f0f1f0;overflow:hidden;border:1px solid #e0e3e5;border-radius:10px;--split:50%}.photo-base,.corrected-layer,.corrected-layer img{position:absolute;inset:0;width:100%;height:100%}.comparison img{object-fit:contain;display:block}.corrected-layer{clip-path:inset(0 calc(100% - var(--split)) 0 0)}.compare-line{position:absolute;left:var(--split);top:0;bottom:0;width:2px;background:#fff;box-shadow:0 0 0 1px #203c7a55}.compare-line span{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);display:grid;place-items:center;background:#fff;border:1px solid #b8c3e8;width:32px;height:32px;border-radius:50%;color:var(--blue)}.photo-label{position:absolute;top:12px;padding:5px 9px;background:#fffef5eb;border:1px solid #dfe1e5;font-size:11px;border-radius:5px;color:#222838}.label-left{left:12px}.label-right{right:12px}#compare-controls{padding-top:20px}#compare-controls label{font-size:12px}#split{margin:8px 0}.compare-buttons{display:flex;gap:8px;justify-content:center}.compare-buttons button{border:1px solid #c8cfde;border-radius:7px;background:white;padding:7px 13px;font-size:11px;color:#384978}.compare-buttons button:hover{background:#eef1fb}.observation{font-size:12px;color:#626676;line-height:1.9;margin:22px 0}.photo-selector{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.photo-selector button{border:2px solid #e1e3e8;border-radius:9px;background:#f6f6f2;overflow:hidden;padding:0;color:#525967}.photo-selector button[aria-pressed=true]{border-color:var(--blue);color:var(--blue);background:#edf0ff}.photo-selector img{width:100%;height:72px;object-fit:cover;display:block}.photo-selector span{display:block;padding:9px 2px;font-size:11px;font-weight:600}.lab-controls{padding:28px 24px;background:#f7f8fb;border-left:1px solid var(--line)}.lab-controls h2{font-size:22px;margin-bottom:26px}.lab-controls .eyebrow{font-size:10px;margin-bottom:10px}.lab-controls label{font-size:12px;font-weight:650}.lab-controls select{width:100%;padding:11px 8px;margin:9px 0 25px;border:1px solid #c6cede;border-radius:7px;background:white;color:var(--ink);font-size:13px}.small-note{font-size:11px!important;color:var(--muted);line-height:1.9}.lab-controls .small-note{margin-top:18px}.lab-reminder{padding-top:22px;border-top:1px solid #dfe2ec;margin-top:28px}.lab-reminder strong{font-size:12px}.lab-reminder p{font-size:12px;color:var(--muted);line-height:1.9}.lab-controls ol{padding-left:19px;font-size:13px;color:#4e5972;line-height:1.9}.lab-controls li{margin:0 0 13px}#image-status{font-size:12px;color:#8b263d;margin:8px 0 0}.practice{padding-bottom:45px}.practice-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px}.practice-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:25px}.practice-card h3{margin:0 0 12px}.practice-card>p{font-size:13px;color:var(--muted)}.reference-colors{display:grid;grid-template-columns:repeat(4,1fr);gap:9px;margin-top:25px}.reference-colors i{display:block;height:83px;border-radius:7px}.reference-colors span,.reference-colors code{display:block;text-align:center;font-size:11px;margin-top:6px}.reference-colors code{font-size:10px;color:#636b79}.region-exercise{display:block;width:100%;margin-top:25px;border-radius:8px}.credits{border-top:1px solid var(--line);padding-top:30px;color:var(--muted)}.credits h2{font-size:17px;color:var(--ink)}.credits p,.credits li{font-size:11px;line-height:1.9}.credits ul{padding-left:18px}.credits a{text-decoration:underline;text-underline-offset:3px}[hidden]{display:none!important}.live-mode .comparison{aspect-ratio:4/3}.notice{padding:15px;background:#fff7dd}
@media(max-width:950px){.lab-workspace{grid-template-columns:minmax(0,1fr) 245px}.lab-controls{padding:25px 18px}.image-workspace{padding:20px}.lab-heading h1{font-size:42px}.practice-grid{gap:16px}.practice-card{padding:20px}}
@media(max-width:680px){.lab-heading{padding-top:35px}.lab-heading h1{font-size:37px;line-height:1.3}.lab-heading h1 span{display:block}.lab-heading>p:last-child{font-size:13px}.mode-picker{width:100%;gap:4px}.mode-picker button{flex:1;padding:10px 7px;font-size:11px}.mode-help{font-size:11px}.lab-workspace{grid-template-columns:1fr}.image-workspace{padding:17px}.lab-controls{border-left:0;border-top:1px solid var(--line);padding:24px}.photo-selector{gap:7px}.photo-selector img{height:58px}.photo-selector span{font-size:10px}.photo-label{font-size:9px;padding:4px 6px}.comparison{aspect-ratio:1}.practice-grid{grid-template-columns:1fr}.reference-colors i{height:70px}.lab .section-head>p{max-width:none}.header nav>a:first-child{display:inline}.header nav>a[href="index.html#install"]{display:none}}
.compare-line{cursor:ew-resize;touch-action:none;user-select:none;z-index:2}.compare-line:before{content:"";position:absolute;inset:0 -14px}.comparison img{user-select:none;pointer-events:none}.compare-buttons button[aria-pressed=true]{background:#edf0ff;border-color:var(--blue);color:var(--blue)}