@font-face{font-family:Geist;font-style:normal;font-display:swap;font-weight:100 900;src:url(https://cdn.jsdelivr.net/fontsource/fonts/geist:vf@latest/latin-wght-normal.woff2) format("woff2-variations")}:root{--font-sans: "Geist", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;--bg: #faf9f7;--fg: #18181b;--muted: #71717a;--border: #e4e4e7;--primary: #7c3aed;--primary-dark: #6d28d9;--amber: #f59e0b;--amber-dark: #b45309}*{box-sizing:border-box}html,body{margin:0}body{font-family:var(--font-sans);background:var(--bg);color:var(--fg);font-size:16px;line-height:1.5;-webkit-font-smoothing:antialiased}a{color:var(--primary);text-decoration:none}a:hover{color:var(--primary-dark)}::-moz-selection{background:var(--primary);color:#fff}::selection{background:var(--primary);color:#fff}.ui-btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:none;border-radius:10px;padding:10px 16px;font-family:inherit;font-size:14.5px;font-weight:600;cursor:pointer;transition:background .12s,box-shadow .15s,opacity .12s;white-space:nowrap}.ui-btn--lg{padding:12px 20px;font-size:15px;border-radius:11px}.ui-btn--sm{padding:8px 14px;font-size:13.5px;border-radius:9px}.ui-btn--outline{background:#fff;border:1px solid var(--border);color:var(--fg)}.ui-btn--outline:hover{background:#f4f4f5}.ui-btn:disabled{pointer-events:none;opacity:.5}.ui-badge{display:inline-flex;align-items:center;gap:5px;border-radius:999px;padding:3px 10px;font-size:12.5px;font-weight:700;line-height:1.4}.ui-avatar{display:inline-flex;align-items:center;justify-content:center;width:36px;height:36px;border-radius:999px;font-size:13px;flex-shrink:0}.ui-avatar--lg{width:44px;height:44px;font-size:15px;border-radius:13px}.ui-input{width:100%;border:1px solid var(--border);border-radius:11px;padding:12px 14px;font-family:inherit;font-size:15px;background:#fff;color:var(--fg);transition:border-color .12s}.ui-input:focus{outline:none;border-color:var(--primary)}.ui-card{background:#fff;border:1px solid var(--border);border-radius:16px;box-shadow:0 1px 2px #0000000a}.lesson-content{font-size:16px;line-height:1.65;color:#3f3f46;margin-top:14px;text-wrap:pretty}.lesson-content>*:first-child{margin-top:0}.lesson-content>*:last-child{margin-bottom:0}.lesson-content p{margin:0 0 14px}.lesson-content h1,.lesson-content h2,.lesson-content h3,.lesson-content h4{color:var(--fg);font-weight:700;letter-spacing:-.01em;line-height:1.3;margin:24px 0 10px}.lesson-content h1{font-size:22px}.lesson-content h2{font-size:19px}.lesson-content h3{font-size:17px}.lesson-content h4{font-size:16px}.lesson-content ul,.lesson-content ol{margin:0 0 14px;padding-left:22px}.lesson-content li{margin-bottom:6px}.lesson-content li>p{margin:0}.lesson-content a{color:var(--primary);text-decoration:underline}.lesson-content strong{color:var(--fg);font-weight:700}.lesson-content blockquote{margin:0 0 14px;padding:2px 0 2px 16px;border-left:3px solid var(--primary);color:var(--muted)}.lesson-content hr{margin:22px 0;border:none;border-top:1px solid var(--border)}.lesson-content code{padding:2px 6px;border-radius:6px;background:#f4f4f5;font-size:14px}.lesson-content pre{margin:0 0 14px;padding:14px 16px;border-radius:12px;background:#f4f4f5;overflow-x:auto}.lesson-content pre code{padding:0;background:none}.lesson-content img{max-width:100%;height:auto;border-radius:12px}.lesson-content ul[data-type=taskList]{padding-left:0;list-style:none}.lesson-content ul[data-type=taskList] li{display:flex;align-items:flex-start;gap:8px}