:root{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;--bg:#f8fafc;--surface:#fff;--surface-strong:#f1f5f9;--ink:#0f172a;--muted:#64748b;--line:#dbe3ed;--line-strong:#bac7d5;--accent:#2563eb;--accent-strong:#1d4ed8;--success:#15803d82;--code-bg:#111827;--code-fg:#e5e7eb;--shadow:0 18px 45px #0f172a14}*{box-sizing:border-box}html{scrollbar-gutter:stable;overflow-y:scroll}body{background:var(--bg);min-width:320px;color:var(--ink);margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;line-height:1.6}button,select{font:inherit}button{border:0}svg{width:18px;height:18px}.shell{grid-template-columns:minmax(280px,336px) minmax(0,1fr);min-height:100vh;display:grid}.sidebar{background:var(--surface);border-right:1px solid var(--line);flex-direction:column;align-self:start;gap:18px;height:100dvh;min-height:0;padding:24px;display:flex;position:sticky;top:0;overflow:hidden}.sidebar-fixed{flex:none;gap:18px;display:grid}.brand{grid-template-columns:48px minmax(0,1fr);align-items:center;gap:8px;min-width:0;display:grid}.brand img{width:44px;height:44px}.brand span,.brand strong{display:block}.brand span{color:var(--ink);text-overflow:ellipsis;white-space:nowrap;font-size:17px;font-weight:900;line-height:1.18;overflow:hidden}.brand strong{color:var(--muted);margin-top:2px;font-size:13px;font-weight:650}.progress-panel{border:1px solid var(--line);background:#fbfdff;border-radius:8px;padding:16px}.progress-row{color:var(--muted);justify-content:space-between;gap:12px;font-size:14px;display:flex}.progress-row strong{color:var(--ink)}.progress{background:var(--surface-strong);height:8px;box-shadow:inset 0 0 0 1px var(--line);border-radius:999px;margin:12px 0 0;overflow:hidden}.progress span{border-radius:inherit;background:var(--success);height:100%;transition:width .18s;display:block}.mobile-lesson-picker{display:none}.course-list{overscroll-behavior:contain;scrollbar-color:#64748b73 transparent;scrollbar-gutter:stable;scrollbar-width:thin;flex:auto;gap:10px;min-height:0;margin-right:-12px;padding-right:12px;display:grid;overflow-y:auto}.course-list::-webkit-scrollbar{width:8px}.course-list::-webkit-scrollbar-track{background:0 0}.course-list::-webkit-scrollbar-thumb{border:2px solid var(--surface);background:#64748b6b;border-radius:999px}.course-item{cursor:pointer;width:100%;min-height:70px;color:var(--ink);text-align:left;background:0 0;border:1px solid #0000;border-radius:8px;grid-template-columns:32px minmax(0,1fr) 18px;align-items:center;gap:12px;padding:0 12px;display:grid}.course-item:hover,.course-item:focus-visible{background:var(--surface-strong);border-color:var(--surface-strong);outline:none}.course-item.selected{background:var(--surface-strong);border-color:var(--line)}.course-number{color:#666;background:var(--line);border-radius:8px;place-items:center;width:34px;height:34px;font-size:12px;font-weight:700;display:inline-grid}.course-item.selected .course-number{color:#fff;background:var(--success)}.course-meta{min-width:0}.course-meta span{display:block}.course-title{overflow-wrap:anywhere;text-overflow:ellipsis;white-space:nowrap;margin-bottom:4px;font-size:14px;font-weight:500;line-height:1.35;overflow:hidden}.course-title+span{color:var(--muted);font-size:12px}.course-check{width:18px;height:18px;color:var(--surface);border-radius:999px;flex:0 0 18px;place-items:center;display:grid}.course-check.done{background:var(--success)}.course-check svg{width:12px;height:12px}.content{min-width:0;padding:32px clamp(16px,5vw,48px) 56px}@media (width<=900px){.shell{grid-template-columns:minmax(238px,286px) minmax(0,1fr)}.sidebar{padding:18px}.content{padding:22px 18px 40px}}@media (width<=640px){.shell{display:block}.sidebar{border-right:0;border-bottom:1px solid var(--line);height:auto;padding:16px;position:static}.brand span{white-space:normal}.mobile-lesson-picker{gap:8px;display:grid}.mobile-lesson-picker span{color:var(--ink);font-size:14px;font-weight:850}.mobile-lesson-picker select{width:100%;min-height:48px;color:var(--accent-strong);background:#eff6ff;border:1px solid #bfdbfe;border-radius:8px;padding:0 12px;font-weight:800}.course-list{display:none}}.lesson-hero{background:var(--surface);border:1px solid var(--line);width:100%;box-shadow:var(--shadow);border-radius:8px;justify-content:space-between;align-items:flex-start;gap:24px;margin:0 0 20px;padding:30px;display:flex}.eyebrow{color:var(--accent-strong);margin-bottom:8px;font-size:13px;font-weight:800}.lesson-hero h2{letter-spacing:0;margin:0;font-size:clamp(28px,4vw,44px);line-height:1.12}.lesson-hero p{max-width:760px;color:var(--muted);margin:12px 0 0;font-size:17px}.status-pill{color:var(--accent-strong);background:#eff6ff;border:1px solid #bfdbfe;border-radius:999px;flex:none;padding:7px 11px;font-size:13px;font-weight:800}.status-pill.done{color:var(--success);background:#f0fdf4;border-color:#bbf7d0}.tabs,.panel{width:100%}.tabs{gap:8px;margin-bottom:14px;display:flex}.tabs button{cursor:pointer;min-width:118px;min-height:44px;color:var(--muted);border:1px solid var(--line);background:var(--surface);border-radius:8px;justify-content:center;align-items:center;gap:8px;padding:10px 14px;font-weight:800;display:inline-flex}.tabs button.active{color:var(--surface);border-color:var(--ink);background:var(--ink)}.panel{background:var(--surface);border:1px solid var(--line);border-radius:8px;padding:28px}.section-head{justify-content:space-between;align-items:center;gap:16px;margin-bottom:16px;display:flex}.section-head h3{margin:0;font-size:22px;line-height:1.25}.method-list{gap:12px;display:grid}.method-card{background:var(--surface-strong);border:1px solid var(--line);border-left:4px solid var(--accent);border-radius:8px;padding:12px 16px;display:grid}.method-card h4{margin:0;font-size:16px;font-weight:400;line-height:1.4}.method-card p{color:var(--muted);margin:4px 0 0;font-size:15px}.code-head{margin-top:30px}.examples{gap:16px;display:grid}.code-card{background:var(--code-bg);border:1px solid #263244;border-radius:8px;overflow:hidden}.code-title{color:#dbeafe;border-bottom:1px solid #263244;justify-content:space-between;align-items:center;gap:12px;padding:12px 16px;display:flex}.code-title span{align-items:center;gap:8px;min-width:0;font-weight:800;display:inline-flex}.code-title small{color:#93c5fd;text-transform:uppercase;font-size:12px;font-weight:800}pre{background:var(--code-bg);margin:0;overflow:auto}code{min-width:max-content;color:var(--code-fg);tab-size:2;padding:18px;font-family:SFMono-Regular,Consolas,Liberation Mono,Menlo,monospace;font-size:14px;line-height:1.7;display:block}.code-comment{color:#86efac}.code-string{color:#fde68a}.code-keyword{color:#93c5fd}.code-component{color:#f9a8d4}.code-prop{color:#67e8f9}.review-head{align-items:flex-start}.qa-list{gap:12px;display:grid}.qa-card{border:1px solid var(--line);background:var(--surface-strong);border-radius:8px}.qa-card summary{cursor:pointer;align-items:center;gap:10px;min-height:54px;padding:15px 18px;list-style:none;display:flex}.qa-card summary:after{content:"+";color:var(--accent-strong);margin-left:auto}.qa-card[open] summary:after{content:"-"}.qa-card summary::-webkit-details-marker{display:none}.qa-card summary span{color:var(--accent-strong);place-items:center;font-size:13px;display:inline-grid}.qa-answer{gap:8px;padding:0 18px 18px 44px;display:grid}.qa-answer strong{width:max-content;color:var(--accent-strong);background:#eff6ff;border:1px solid #bfdbfe;border-radius:999px;padding:3px 8px;font-size:12px;font-weight:900}.qa-answer p{color:var(--muted);margin:0}.review-actions{justify-content:flex-start;margin-top:20px;display:flex}.complete-button{cursor:pointer;min-width:108px;min-height:40px;color:var(--surface);background:var(--success);border-radius:8px;padding:9px 14px;font-weight:800}.complete-button.done{cursor:default;color:#f8fafc;background:#94a3b8}@media (width<=900px){.method-card{grid-template-columns:1fr;gap:8px}}@media (width<=640px){.lesson-hero,.panel{padding:20px}.lesson-hero{flex-direction:column}.lesson-hero h2{font-size:30px}.tabs{grid-template-columns:1fr 1fr;display:grid}.tabs button{min-width:0}.section-head{flex-direction:column;align-items:stretch}.qa-card summary{align-items:flex-start}.qa-answer{padding-left:18px}.review-actions{display:block}.complete-button{width:100%}}