:root{--color-text: #1c1f24;--color-text-body: #2a2f36;--color-text-secondary: #3d434c;--color-text-muted: #6b7280;--color-bg: #ffffff;--color-surface: #f6f7f9;--color-surface-subtle: #fbfbfc;--color-border: #e3e6ea;--color-divider: #eceef1;--color-border-input: #d9dce1;--color-text-faint: #b8bdc6;--color-chapter-row: #fafaff;--color-chapter-row-border: #eceefc;--color-chapter-mark-border: #e2e5f8;--color-backdrop: rgb(28 31 36 / .45);--shadow-dialog: 0 12px 40px rgb(28 31 36 / .18);--color-action: #4347c9;--color-action-hover: #2f32a3;--color-on-action: #ffffff;--color-lesson: var(--color-action);--color-lesson-soft: #eef0ff;--color-lesson-on-soft: #2f32a3;--color-example: #0b7285;--color-example-soft: #e3f4f7;--color-example-on-soft: #0a5e6e;--color-example-code-bg: #f2fafb;--color-example-border: #cbe6ec;--color-quiz: #7a4bc2;--color-quiz-soft: #f3eefc;--color-quiz-on-soft: #5b3597;--color-exercise: #c2570c;--color-exercise-soft: #fff1e6;--color-exercise-on-soft: #9a4309;--color-memo: #55627a;--color-memo-soft: #eef1f5;--color-memo-on-soft: #55627a;--color-success: #1f7a4d;--color-success-soft: #e6f4ec;--color-error: #a1202f;--color-error-soft: #fdecee;--color-error-on-soft: #3a1418;--color-error-hover: #861a27;--color-podium-1-soft: #fdf3d3;--color-podium-1-on-soft: #7a5a00;--color-podium-1: #d4a514;--color-podium-2-soft: #eceff3;--color-podium-2-on-soft: #4a5261;--color-podium-2: #a3acb9;--color-podium-3-soft: #f8e9dc;--color-podium-3-on-soft: #8a4b1c;--color-podium-3: #c07a45;--syntax-keyword: #8b3fb8;--syntax-string: #1d7a46;--syntax-number: #b0550a;--syntax-comment: #7a818c;--syntax-function: #4347c9;--font-heading: "Manrope", "Segoe UI", system-ui, sans-serif;--font-body: "Lexend", "Segoe UI", system-ui, sans-serif;--font-code: "JetBrains Mono", ui-monospace, "Cascadia Code", monospace;--font-body-weight: 300;--line-height-body: 1.75;--line-height-lead: 1.6;--text-xs: 12.5px;--text-sm: 13px;--text-md: 14px;--text-base: 15px;--text-lg: 16px;--text-xl: 18px;--text-2xl: 20px;--text-3xl: 24px;--text-4xl: 34px;--text-5xl: 44px;--font-body-size: var(--text-xl);--font-lead-size: var(--text-2xl);--font-h1-size: var(--text-5xl);--font-h2-size: var(--text-3xl);--font-tag-size: var(--text-xs);--reading-width: 700px;--wide-width: 800px;--header-height: 64px;--logo-mark-height: 30px;--sticky-gap: 16px;--layer-sticky: 10;--page-gutter: 40px;--form-width: 440px;--aside-width: 220px;--statement-width: 500px;--progress-width: 120px;--account-menu-width: 200px;--podium-width: 480px;--podium-avatar: 48px;--podium-avatar-first: 60px;--profile-avatar: 96px;--header-avatar: 32px;--podium-step-1: 88px;--podium-step-2: 64px;--podium-step-3: 44px;--badge-medal: 64px;--badge-icon: 28px;--badge-locked-opacity: .45;--badge-zoom: 256px;--badge-dialog-width: 360px;--space-2: 2px;--space-4: 4px;--space-6: 6px;--space-8: 8px;--space-10: 10px;--space-11: 11px;--space-12: 12px;--space-14: 14px;--space-16: 16px;--space-18: 18px;--space-20: 20px;--space-22: 22px;--space-24: 24px;--space-28: 28px;--space-32: 32px;--space-40: 40px;--space-44: 44px;--space-56: 56px;--space-72: 72px;--radius-bar: 3px;--radius-tag: 6px;--radius-control: 8px;--radius-button: 10px;--radius-card: 12px}@font-face{font-family:Manrope;src:url(/fonts/manrope-latin-var.woff2) format("woff2");font-weight:200 800;font-display:swap}@font-face{font-family:Lexend;src:url(/fonts/lexend-latin-var.woff2) format("woff2");font-weight:300 600;font-display:swap}@font-face{font-family:JetBrains Mono;src:url(/fonts/jetbrains-mono-latin-var.woff2) format("woff2");font-weight:400 700;font-display:swap}*,*:before,*:after{box-sizing:border-box}html{-webkit-text-size-adjust:100%;scroll-padding-top:calc(var(--header-height) + var(--sticky-gap))}body{margin:0;background:var(--color-bg);color:var(--color-text);font-family:var(--font-heading);-webkit-font-smoothing:antialiased}h1,h2,h3{margin:0;font-family:var(--font-heading);font-weight:800}h1{font-size:var(--font-h1-size);line-height:1.1;letter-spacing:-.02em}h2{font-size:var(--font-h2-size);letter-spacing:-.01em}p{margin:0}code{font-family:var(--font-code);font-size:.9em}a{color:var(--color-action)}a:hover{color:var(--color-action-hover)}:focus-visible{outline:2px solid var(--color-action);outline-offset:2px}.tag{display:inline-block;padding:var(--space-4) var(--space-10);border-radius:var(--radius-tag);font-size:var(--font-tag-size);font-weight:700;background:var(--color-lesson-soft);color:var(--color-lesson-on-soft)}.lead{font-family:var(--font-body);font-weight:var(--font-body-weight);font-size:var(--font-lead-size);line-height:var(--line-height-lead);color:var(--color-text-secondary)}.btn-secondary{font-family:var(--font-heading);font-size:var(--text-md);font-weight:600;padding:var(--space-8) var(--space-14);border-radius:var(--radius-control);border:1px solid var(--color-border-input);background:var(--color-bg);color:var(--color-text-secondary);cursor:pointer}.btn-secondary:hover:not(:disabled){border-color:var(--color-text-muted);color:var(--color-text)}.btn-secondary:disabled{cursor:default;opacity:.6}