:root{--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark;color:#f3f0e8;--app-bg:#111212;--surface:#171918;--surface-raised:#202422;--surface-soft:#181d1b;--border:#2c302f;--border-strong:#3a403d;--text:#f3f0e8;--text-muted:#c2c9c4;--text-soft:#9ba59f;--accent:#e5c662;--accent-strong:#caa73e;--success:#7fc98b;--danger:#d66a5f;background:#111212;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}:root[data-theme=light]{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;color:#242728;--app-bg:#f7f4ec;--surface:#fffdf7;--surface-raised:#f0ece1;--surface-soft:#faf7ef;--border:#ddd6c8;--border-strong:#c7bdab;--text:#242728;--text-muted:#4f5955;--text-soft:#6f7975;--accent:#2f7f75;--accent-strong:#21695f;--success:#2c8a4a;--danger:#bb483d;background:#f7f4ec}*{box-sizing:border-box}body{min-width:320px;min-height:100vh;margin:0}button{font:inherit}.app-shell{background:var(--app-bg);grid-template-columns:auto 1fr;min-height:100vh;display:grid}.sidebar{border-right:1px solid var(--border);background:var(--surface);width:292px;min-height:100vh;color:var(--text);transition:width .16s}.sidebar.is-collapsed{width:76px}.sidebar-header{border-bottom:1px solid var(--border);justify-content:space-between;align-items:flex-start;gap:12px;padding:22px 18px;display:flex}.sidebar-header h1,.panel-toolbar h2,.lesson-panel h2,.test-panel h2{letter-spacing:0;margin:0}.sidebar-header h1{max-width:190px;font-size:20px;line-height:1.15}.sidebar-actions{flex:none;gap:8px;display:flex}.eyebrow,.section-label{color:var(--text-soft);text-transform:uppercase;margin:0;font-size:12px;font-weight:700}.icon-button,.icon-text-button,.run-button{border:1px solid var(--border-strong);background:var(--surface-raised);color:var(--text);cursor:pointer;justify-content:center;align-items:center;display:inline-flex}.icon-button{border-radius:6px;flex:none;width:36px;height:36px}.icon-text-button,.run-button{border-radius:6px;gap:8px;min-height:36px;padding:0 14px}.run-button{border-color:var(--accent);background:var(--accent);color:var(--app-bg);font-weight:800}.run-button:disabled{cursor:wait;opacity:.72}.progress-block{border:1px solid var(--border);background:var(--surface-soft);border-radius:8px;justify-content:space-between;align-items:center;gap:12px;margin:14px 12px 0;padding:12px;display:flex}.progress-block strong{margin-top:4px;font-size:20px;display:block}.progress-block span{color:var(--accent);font-size:13px;font-weight:800}.sidebar-search{border:1px solid var(--border);background:var(--surface-soft);min-height:40px;color:var(--text-soft);border-radius:8px;grid-template-columns:18px minmax(0,1fr) 28px;align-items:center;gap:8px;margin:14px 12px 0;padding:0 6px 0 10px;display:grid}.sidebar-search input{min-width:0;color:var(--text);font:inherit;background:0 0;border:0;outline:0}.sidebar-search input::placeholder{color:var(--text-soft)}.search-clear,.bookmark-button{color:var(--text-soft);cursor:pointer;background:0 0;border:0;border-radius:6px;justify-content:center;align-items:center;display:inline-flex}.search-clear{width:28px;height:28px}.lesson-nav{gap:22px;padding:18px 12px;display:grid}.lesson-group{gap:8px;display:grid}.section-label{padding:0 10px}.lesson-row{grid-template-columns:minmax(0,1fr) 34px;align-items:center;gap:4px;display:grid}.lesson-link{width:100%;min-height:42px;color:var(--text-muted);text-align:left;cursor:pointer;background:0 0;border:0;border-radius:6px;grid-template-columns:28px 1fr;align-items:center;gap:10px;padding:6px 10px;display:grid}.is-collapsed .lesson-link{grid-template-columns:28px;justify-content:center}.is-collapsed .lesson-row{grid-template-columns:1fr}.lesson-link.is-active{background:var(--accent);color:var(--app-bg)}.lesson-link:disabled{color:var(--text-soft);cursor:not-allowed;opacity:.68}.lesson-status{border:1px solid;border-radius:50%;justify-content:center;align-items:center;width:28px;height:28px;font-size:12px;font-weight:800;display:inline-flex}.bookmark-button{width:34px;height:34px}.bookmark-button:hover,.bookmark-button.is-active,.bookmark-toggle.is-active,.search-clear:hover{color:var(--accent)}.lesson-divider{background:var(--border);height:1px}.empty-lessons{color:var(--text-soft);margin:0;padding:8px 10px;font-size:13px}.workspace{grid-template-columns:minmax(320px,.9fr) minmax(460px,1.1fr);gap:0;min-width:0;display:grid}.lesson-panel,.code-panel{min-width:0;min-height:100vh}.lesson-panel{border-right:1px solid var(--border);color:var(--text);padding:42px clamp(24px,4vw,56px)}.lesson-panel-header{justify-content:space-between;align-items:center;gap:16px;display:flex}.lesson-kicker{color:var(--text-soft);flex-wrap:wrap;align-items:center;gap:10px;font-size:13px;font-weight:700;display:flex}.lesson-panel h2{max-width:720px;margin-top:18px;font-size:44px;line-height:1.02}.objective{max-width:680px;color:var(--text-muted);margin:18px 0 34px;font-size:18px;line-height:1.6}.lesson-copy{max-width:720px;color:var(--text-muted);gap:14px;line-height:1.65;display:grid}.lesson-copy h3{color:var(--text);margin:18px 0 0;font-size:15px}.lesson-copy p{margin:0}.diagram{border:1px solid var(--border-strong);background:var(--surface-soft);color:var(--text);border-radius:8px;grid-template-columns:minmax(0,1fr) auto minmax(0,1fr);align-items:center;gap:12px;margin:10px 0;padding:16px;font-weight:700;display:grid}.diagram span{min-width:0}.code-panel{background:var(--surface);grid-template-rows:auto minmax(360px,1fr) auto;display:grid}.panel-toolbar{border-bottom:1px solid var(--border);justify-content:space-between;align-items:center;gap:16px;min-height:82px;padding:18px 22px;display:flex}.panel-toolbar h2,.test-panel h2{margin-top:4px;font-size:18px}.editor-frame{min-height:360px}.test-panel{border-top:1px solid var(--border);background:var(--surface-soft)}.test-panel-header{border-bottom:1px solid var(--border);justify-content:space-between;align-items:center;gap:16px;padding:16px 22px;display:flex}.test-list{gap:8px;padding:14px 22px 20px;display:grid}.test-result{min-height:34px;color:var(--text-soft);grid-template-columns:20px minmax(0,1fr);align-items:center;gap:10px;display:grid}.test-result.is-passing{color:var(--success)}.test-result.is-failing{color:var(--danger)}.test-result small{min-width:0;color:var(--text-muted);overflow-wrap:anywhere;grid-column:2;font-size:12px;line-height:1.45}@media (width<=1040px){.workspace{grid-template-columns:1fr}.lesson-panel,.code-panel{min-height:auto}.lesson-panel{border-right:0;border-bottom:1px solid var(--border)}.editor-frame{height:520px}}@media (width<=720px){.app-shell{grid-template-columns:1fr}.sidebar,.sidebar.is-collapsed{border-right:0;border-bottom:1px solid var(--border);width:100%;min-height:auto}.sidebar.is-collapsed .lesson-nav,.sidebar.is-collapsed .progress-block{display:none}.lesson-panel{padding:28px 18px}.lesson-panel h2{font-size:34px}.objective{font-size:16px}.diagram{grid-template-columns:1fr}.panel-toolbar,.test-panel-header{padding:16px}.test-list{padding-inline:16px}}