chapter-toc[data-astro-cid-p33bl5ka]{font-size:14px;display:block}summary[data-astro-cid-p33bl5ka]{color:#0f172a;margin-bottom:14px;font-weight:650}ol[data-astro-cid-p33bl5ka]{border-left:1px solid #e2e8f0;margin:0;padding:0;list-style:none}a[data-astro-cid-p33bl5ka]{color:#64748b;overflow-wrap:anywhere;border-left:2px solid #0000;margin-left:-1px;padding:7px 0 7px 16px;line-height:1.6;display:block}a[data-astro-cid-p33bl5ka]:hover,a[data-astro-cid-p33bl5ka][aria-current=location]{color:#2563eb}a[data-astro-cid-p33bl5ka][aria-current=location]{border-left-color:#2563eb}.nested[data-astro-cid-p33bl5ka] a[data-astro-cid-p33bl5ka]{padding-left:28px}@media (width>=1024px){summary[data-astro-cid-p33bl5ka]{pointer-events:none;list-style:none}summary[data-astro-cid-p33bl5ka]::-webkit-details-marker{display:none}}@media (width<=1023px){details[data-astro-cid-p33bl5ka]{border-block:1px solid #e2e8f0;padding:14px 0}summary[data-astro-cid-p33bl5ka]{margin-bottom:0}details[data-astro-cid-p33bl5ka][open] summary[data-astro-cid-p33bl5ka]{margin-bottom:12px}}.lesson-shell{padding-top:32px}body:has(.lesson-shell){background:#fff}.document-grid{grid-template-columns:minmax(0,1fr) 200px;align-items:start;gap:48px;display:grid}.document-content{min-width:0}.document-content .prose{text-align:left;max-width:none;margin:0;padding:16px 0 4px}.document-content .prose>:first-child{margin-top:0}.document-content .prose>:last-child{margin-bottom:0}.document-content .prose .expressive-code{margin:14px 0}.document-toc{max-height:calc(100vh - 64px);position:sticky;top:32px;overflow-y:auto}.document-content [id^=chapter-section-]{scroll-margin-top:32px}.document-content>h2{margin:32px 0 16px;font-size:26px;font-weight:650}.document-content>h3{margin:24px 0 12px;font-size:20px;font-weight:650}.document-content>p{color:#334155;margin:12px 0 20px;line-height:1.9}@media (width<=1023px){.document-grid{grid-template-columns:minmax(0,1fr);gap:24px}.document-toc{grid-row:1;max-height:none;position:static}.document-toc:not(:has(chapter-toc)){display:none}}.homework-tabs [role=tablist]{border:0;background:0 0;border-bottom:1px solid #e2e8f0;border-radius:0;justify-content:flex-start;gap:28px;width:100%;height:auto;padding:0;display:flex}.homework-tabs [role=tab]{color:#475569;height:auto;min-height:40px;box-shadow:none;background:0 0;border:0;border-bottom:2px solid #0000;border-radius:0;flex:none;padding:8px 0;font-size:15px;font-weight:500;position:relative}.homework-tabs [role=tab][aria-selected=true]{color:#2563eb;box-shadow:none;background:0 0;border-bottom-color:#2563eb}.homework-tabs [role=tabpanel]{margin-top:0}box-model-demo[data-astro-cid-xoxbbwrs]{background:#f8fafc;border:1px solid #e2e8f0;border-radius:8px;margin:12px 0 32px;padding:24px;display:block}.box-model-figure[data-astro-cid-xoxbbwrs]{text-align:center;margin:0}.margin-layer[data-astro-cid-xoxbbwrs]{background:#e2e8f0;border:1px dashed #94a3b8;max-width:560px;margin:0 auto;padding:24px}.border-layer[data-astro-cid-xoxbbwrs]{background:#dbeafe;border:2px solid #2563eb;padding:18px;position:relative}.padding-layer[data-astro-cid-xoxbbwrs]{background:#ccfbf1;border:1px dashed #0f766e;padding:20px;position:relative}.content-layer[data-astro-cid-xoxbbwrs]{color:#1e3a8a;background:#fff;border:1px solid #bfdbfe;place-items:center;min-height:96px;padding:16px;font-weight:650;display:grid}.content-layer[data-astro-cid-xoxbbwrs] small[data-astro-cid-xoxbbwrs]{color:#475569;font-size:12px;font-weight:400}.layer-label[data-astro-cid-xoxbbwrs]{color:#334155;text-align:left;font-size:12px;line-height:1.4;display:block}.margin-label[data-astro-cid-xoxbbwrs]{margin:-18px 0 6px}.border-label[data-astro-cid-xoxbbwrs]{color:#1d4ed8;margin:-14px 0 6px}.padding-label[data-astro-cid-xoxbbwrs]{color:#0f766e;margin:-14px 0 6px}figcaption[data-astro-cid-xoxbbwrs]{color:#475569;margin-top:16px;font-size:13px}.box-model-notes[data-astro-cid-xoxbbwrs]{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;max-width:560px;margin:20px auto 0;display:grid}.box-model-notes[data-astro-cid-xoxbbwrs] div[data-astro-cid-xoxbbwrs]{text-align:left;background:#fff;border:1px solid #e2e8f0;border-radius:6px;padding:12px 14px}.box-model-notes[data-astro-cid-xoxbbwrs] strong[data-astro-cid-xoxbbwrs],.box-model-notes[data-astro-cid-xoxbbwrs] span[data-astro-cid-xoxbbwrs]{display:block}.box-model-notes[data-astro-cid-xoxbbwrs] strong[data-astro-cid-xoxbbwrs]{color:#0f172a;font-size:13px}.box-model-notes[data-astro-cid-xoxbbwrs] span[data-astro-cid-xoxbbwrs]{color:#64748b;margin-top:4px;font-size:12px;line-height:1.5}@media (width<=560px){box-model-demo[data-astro-cid-xoxbbwrs]{padding:14px}.margin-layer[data-astro-cid-xoxbbwrs]{padding:18px}.border-layer[data-astro-cid-xoxbbwrs],.padding-layer[data-astro-cid-xoxbbwrs]{padding:14px}.box-model-notes[data-astro-cid-xoxbbwrs]{grid-template-columns:1fr}}flow-demo[data-astro-cid-weuthv2v]{background:#f8fafc;border:1px solid #e2e8f0;border-radius:8px;margin:12px 0 32px;padding:24px;display:block}.flow-demo-grid[data-astro-cid-weuthv2v]{grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;max-width:720px;margin:0 auto;display:grid}figure[data-astro-cid-weuthv2v]{min-width:0;margin:0}figcaption[data-astro-cid-weuthv2v]{color:#0f172a;flex-wrap:wrap;justify-content:space-between;align-items:baseline;gap:4px 12px;margin-bottom:8px;font-size:13px;display:flex}figcaption[data-astro-cid-weuthv2v] span[data-astro-cid-weuthv2v]{color:#64748b;font-size:12px}.flow-card[data-astro-cid-weuthv2v]{background:#eff6ff;border:1px solid #bfdbfe;border-radius:6px;gap:8px;min-height:180px;padding:16px;display:grid;position:relative}.flow-card[data-astro-cid-weuthv2v] div[data-astro-cid-weuthv2v]{color:#334155;background:#fff;border:1px solid #dbeafe;border-radius:4px;align-items:center;min-width:0;padding:10px 12px;font-size:13px;display:flex}.flow-card[data-astro-cid-weuthv2v] div[data-astro-cid-weuthv2v]:nth-of-type(2){color:#1e40af}.positioned-card[data-astro-cid-weuthv2v] b[data-astro-cid-weuthv2v]{z-index:1;color:#fff;letter-spacing:.05em;background:#2563eb;border-radius:4px;padding:3px 7px;font-size:10px;position:absolute;inset-block-start:10px;inset-inline-end:10px}.positioned-card[data-astro-cid-weuthv2v] div[data-astro-cid-weuthv2v]:first-of-type{padding-inline-end:52px}flow-demo[data-astro-cid-weuthv2v]>p[data-astro-cid-weuthv2v]{color:#64748b;max-width:720px;margin:14px auto 0;font-size:13px;line-height:1.6}@media (width<=600px){flow-demo[data-astro-cid-weuthv2v]{padding:14px}.flow-demo-grid[data-astro-cid-weuthv2v]{grid-template-columns:1fr}.flow-card[data-astro-cid-weuthv2v]{min-height:0}}grid-demo[data-astro-cid-3ucfoa3h]{background:#f8fafc;border:1px solid #e2e8f0;border-radius:8px;margin:12px 0 32px;padding:24px;display:block}.grid-demo-frame[data-astro-cid-3ucfoa3h]{grid-template-columns:140px minmax(0,1fr);grid-template-areas:"header header""sidebar main""footer footer";gap:12px;max-width:720px;margin:0 auto;display:grid}.grid-demo-frame[data-astro-cid-3ucfoa3h]>div[data-astro-cid-3ucfoa3h]{color:#1e40af;border:1px solid #bfdbfe;border-radius:6px;flex-wrap:wrap;align-items:center;gap:8px 14px;min-height:54px;padding:14px;font-size:13px;display:flex}.grid-demo-header[data-astro-cid-3ucfoa3h]{background:#dbeafe;grid-area:header}.grid-demo-sidebar[data-astro-cid-3ucfoa3h]{background:#f1f5f9;grid-area:sidebar;align-content:start}.grid-demo-main[data-astro-cid-3ucfoa3h]{background:#eff6ff;grid-area:main;display:block!important}.grid-demo-main[data-astro-cid-3ucfoa3h]>span[data-astro-cid-3ucfoa3h]{color:#475569;margin-top:3px;display:block}.grid-demo-footer[data-astro-cid-3ucfoa3h]{background:#f1f5f9;grid-area:footer}.grid-demo-cards[data-astro-cid-3ucfoa3h]{grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;margin-top:14px;display:grid}.grid-demo-cards[data-astro-cid-3ucfoa3h] i[data-astro-cid-3ucfoa3h]{color:#2563eb;background:#fff;border:1px solid #bfdbfe;border-radius:4px;place-items:center;min-height:64px;font-size:12px;font-style:normal;display:grid}.grid-demo-note[data-astro-cid-3ucfoa3h]{color:#64748b;max-width:720px;margin:14px auto 0;font-size:13px;line-height:1.6}.grid-demo-note[data-astro-cid-3ucfoa3h] code[data-astro-cid-3ucfoa3h]{color:#3730a3;background:#e0e7ff;border-radius:4px;padding:2px 5px}@media (width<=560px){grid-demo[data-astro-cid-3ucfoa3h]{padding:14px}.grid-demo-frame[data-astro-cid-3ucfoa3h]{grid-template-columns:1fr;grid-template-areas:"header""sidebar""main""footer"}.grid-demo-cards[data-astro-cid-3ucfoa3h]{grid-template-columns:1fr}}flex-demo[data-astro-cid-dhxxre5a]{background:#f8fafc;border:1px solid #e2e8f0;border-radius:8px;margin:12px 0 32px;padding:24px;display:block}.flex-demo-stage[data-astro-cid-dhxxre5a]{background:#e2e8f0;border-radius:6px;min-height:118px;padding:12px}.flex-demo-viewport[data-astro-cid-dhxxre5a]{width:100%;max-width:720px;margin:0 auto;transition:max-width .18s}.flex-demo-viewport[data-astro-cid-dhxxre5a][data-size=narrow]{max-width:320px}.flex-demo-frame[data-astro-cid-dhxxre5a]{background:#eff6ff;border:1px solid #bfdbfe;border-radius:6px;flex-wrap:wrap;align-items:center;gap:12px 20px;padding:18px;display:flex}.flex-demo-title[data-astro-cid-dhxxre5a]{color:#1e40af;flex:220px;align-items:baseline;gap:12px;min-width:0;display:flex}.flex-demo-title[data-astro-cid-dhxxre5a] strong[data-astro-cid-dhxxre5a]{flex:none}.flex-demo-title[data-astro-cid-dhxxre5a] span[data-astro-cid-dhxxre5a]{color:#475569;text-overflow:ellipsis;white-space:nowrap;min-width:0;font-size:13px;overflow:hidden}.flex-demo-actions[data-astro-cid-dhxxre5a]{flex:none;gap:8px;display:flex}.flex-demo-actions[data-astro-cid-dhxxre5a] button[data-astro-cid-dhxxre5a]{color:#1d4ed8;background:#fff;border:1px solid #93c5fd;border-radius:5px;padding:6px 12px;font-size:13px}.flex-demo-actions[data-astro-cid-dhxxre5a] button[data-astro-cid-dhxxre5a][aria-pressed=true]{color:#fff;background:#2563eb;border-color:#2563eb}.flex-demo-status[data-astro-cid-dhxxre5a]{color:#475569;max-width:720px;margin:12px auto 0;font-size:13px;line-height:1.6}.flex-demo-axis[data-astro-cid-dhxxre5a]{color:#64748b;flex-wrap:wrap;justify-content:space-between;gap:8px 20px;max-width:720px;margin:8px auto 0;font-size:12px;display:flex}@media (width<=480px){flex-demo[data-astro-cid-dhxxre5a]{padding:14px}.flex-demo-stage[data-astro-cid-dhxxre5a]{padding:8px}.flex-demo-title[data-astro-cid-dhxxre5a]{flex-basis:160px}}@media (prefers-reduced-motion:reduce){.flex-demo-viewport[data-astro-cid-dhxxre5a]{transition:none}}layout-demo[data-astro-cid-g5h5owbz]{margin:12px 0 32px;display:block}.layout-lab[data-astro-cid-g5h5owbz]{background:#fff;border:1px solid #e2e8f0;border-radius:8px;overflow:hidden}.lab-toolbar[data-astro-cid-g5h5owbz]{justify-content:space-between;align-items:center;gap:16px;padding:24px;display:flex}.lab-toolbar[data-astro-cid-g5h5owbz] h2[data-astro-cid-g5h5owbz]{margin:0;font-size:20px;font-weight:650}.lab-toolbar[data-astro-cid-g5h5owbz] p[data-astro-cid-g5h5owbz]{color:#475569;margin:4px 0 0;font-size:14px}button[data-astro-cid-g5h5owbz]{white-space:nowrap;background:#fff;border:1px solid #cbd5e1;border-radius:6px;padding:7px 12px;font-size:14px}button[data-astro-cid-g5h5owbz]:hover{background:#f1f5f9}.lab-controls[data-astro-cid-g5h5owbz]{background:#f8fafc;border-block:1px solid #e2e8f0;grid-template-columns:1fr 1fr 1fr;gap:24px;padding:20px 24px;display:grid}label[data-astro-cid-g5h5owbz]{font-size:14px;font-weight:500;display:block}output[data-astro-cid-g5h5owbz]{float:right;color:#2563eb;font-variant-numeric:tabular-nums}input[data-astro-cid-g5h5owbz]{accent-color:#2563eb;width:100%;margin-top:16px;display:block}select[data-astro-cid-g5h5owbz]{background:#fff;border:1px solid #cbd5e1;border-radius:5px;width:100%;margin-top:8px;padding:6px 10px;display:block}.preview-stage[data-astro-cid-g5h5owbz]{background:#edf2f7;padding:28px}.preview-viewport[data-astro-cid-g5h5owbz]{width:100%;margin:auto;container-type:inline-size}.example-page[data-astro-cid-g5h5owbz]{--sidebar-width:160px;--gap:16px;gap:var(--gap);background:#fff;border:1px solid #cbd5e1;border-radius:6px;padding:16px;display:grid}.example-header[data-astro-cid-g5h5owbz]{color:#1e40af;background:#dbeafe;border:1px solid #bfdbfe;border-radius:4px;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:8px;padding:16px;display:flex}.example-header[data-astro-cid-g5h5owbz] span[data-astro-cid-g5h5owbz],.example-footer[data-astro-cid-g5h5owbz] span[data-astro-cid-g5h5owbz]{font-size:13px}.example-header[data-astro-cid-g5h5owbz] strong[data-astro-cid-g5h5owbz],.example-main[data-astro-cid-g5h5owbz] strong[data-astro-cid-g5h5owbz],.example-sidebar[data-astro-cid-g5h5owbz] strong[data-astro-cid-g5h5owbz]{letter-spacing:.06em;font-size:13px}.example-body[data-astro-cid-g5h5owbz]{grid-template-columns:var(--sidebar-width) minmax(0, 1fr);gap:var(--gap);display:grid}.example-sidebar[data-astro-cid-g5h5owbz]{background:#f1f5f9;border:1px solid #cbd5e1;border-radius:4px;flex-direction:column;gap:14px;padding:16px;display:flex}.example-sidebar[data-astro-cid-g5h5owbz] span[data-astro-cid-g5h5owbz]{color:#475569;font-size:14px}.example-main[data-astro-cid-g5h5owbz]{color:#1e40af;background:#eff6ff;border:1px solid #93c5fd;border-radius:4px;min-width:0;padding:20px}.example-main[data-astro-cid-g5h5owbz] p[data-astro-cid-g5h5owbz]{margin:10px 0 20px;font-size:16px}.example-cards[data-astro-cid-g5h5owbz]{gap:var(--gap);grid-template-columns:repeat(3,minmax(0,1fr));display:grid}.example-cards[data-astro-cid-g5h5owbz] div[data-astro-cid-g5h5owbz]{background:#fff;border:1px solid #bfdbfe;border-radius:4px;place-items:center;min-height:90px;font-size:14px;display:grid}.example-footer[data-astro-cid-g5h5owbz]{color:#475569;background:#f1f5f9;border-radius:4px;flex-wrap:wrap;gap:16px;padding:12px 16px;font-size:13px;display:flex}.lab-status[data-astro-cid-g5h5owbz]{color:#475569;border-bottom:1px solid #e2e8f0;margin:0;padding:15px 24px;font-size:14px}.lab-note[data-astro-cid-g5h5owbz]{padding:20px 24px;font-size:14px}.lab-note[data-astro-cid-g5h5owbz] p[data-astro-cid-g5h5owbz]{color:#475569;margin:5px 0 0}@container (width<=560px){.example-body[data-astro-cid-g5h5owbz],.example-cards[data-astro-cid-g5h5owbz]{grid-template-columns:1fr}.example-sidebar[data-astro-cid-g5h5owbz]{flex-flow:wrap}.example-cards[data-astro-cid-g5h5owbz] div[data-astro-cid-g5h5owbz]{min-height:56px}}@media (width<=600px){.lab-controls[data-astro-cid-g5h5owbz]{grid-template-columns:1fr;gap:20px}.lab-toolbar[data-astro-cid-g5h5owbz]{align-items:start;padding:20px}.preview-stage[data-astro-cid-g5h5owbz]{padding:12px}.example-page[data-astro-cid-g5h5owbz]{padding:10px}}