@font-face{font-family:Outfit;src:url('./fonts/Outfit-Variable.woff2') format('woff2');font-weight:100 900;font-display:swap}
    :root{--color-mho-50:#eff6ff;--color-mho-100:#dbeafe;--color-mho-200:#bfdbfe;--color-mho-300:#93c5fd;--color-mho-400:#60a5fa;--color-mho-500:#3b82f6;--color-mho-600:#2563eb;--color-mho-700:#1d4ed8;--color-mho-800:#1e40af;--color-mho-900:#1e3a8a;--color-navy-950:#0f172a;--color-navy-900:#1e293b;--color-navy-800:#334155;--color-navy-700:#475569;--color-navy-600:#64748b;--color-cyan-400:#22d3ee;--color-cyan-500:#06b6d4;--color-surface:#ffffff;--color-surface-secondary:#f7f8fb;--color-surface-elevated:#ffffff;--color-border:#e5e7eb;--color-border-subtle:#f0f1f3;--color-text-primary:#111827;--color-text-secondary:#6b7280;--color-text-tertiary:#9ca3af;--font-sans:'Outfit', system-ui, sans-serif;--font-mono:'JetBrains Mono', ui-monospace, monospace;--color-background:var(--color-surface-secondary);--color-foreground:var(--color-text-primary);--color-card:var(--color-surface);--color-card-foreground:var(--color-text-primary);--color-popover:var(--color-surface);--color-popover-foreground:var(--color-text-primary);--color-primary:var(--color-mho-600);--color-primary-foreground:#ffffff;--color-secondary:#f1f5f9;--color-secondary-foreground:var(--color-text-primary);--color-muted:var(--color-surface-secondary);--color-muted-foreground:var(--color-text-secondary);--color-accent:#f1f5f9;--color-accent-foreground:var(--color-text-primary);--color-destructive:#dc2626;--color-destructive-foreground:#ffffff;--color-input:var(--color-border);--color-ring:var(--color-mho-600);--color-attention:#b45309;--color-danger:#b91c1c;--color-positive:#047857;--color-panel:#edf0f6;--color-panel-border:#e0e5ee;}
:root{--shadow-raise:0 1px 1px -0.5px rgb(15 23 42 / 0.04),
    0 2px 4px -1.5px rgb(15 23 42 / 0.06),
    0 4px 10px -3px rgb(15 23 42 / 0.05);--shadow-raise-lg:0 1px 1px -0.5px rgb(15 23 42 / 0.05),
    0 4px 8px -2px rgb(15 23 42 / 0.08),
    0 10px 22px -6px rgb(15 23 42 / 0.10);}
.dark{--color-navy-950:#090a0e;--color-navy-900:#171b23;--color-navy-800:#202531;--color-navy-700:#2a303d;--color-navy-600:#5f6474;--color-surface:#171b23;--color-surface-secondary:#090a0e;--color-surface-elevated:#202531;--color-border:#2a303d;--color-border-subtle:#171b23;--color-text-primary:#eaecf3;--color-text-secondary:#9398a8;--color-text-tertiary:#5f6474;color-scheme:dark;--color-secondary:#202531;--color-accent:#202531;--color-destructive:#ef4444;--color-attention:#f59e0b;--color-danger:#ef4444;--color-positive:#22c55e;--color-panel:#202531;--color-panel-border:#2a303d;--shadow-raise:0 1px 0 rgb(2 4 10 / 0.55),
    0 4px 14px rgb(2 4 10 / 0.45);--shadow-raise-lg:0 1px 0 rgb(2 4 10 / 0.55),
    0 6px 20px rgb(1 3 8 / 0.50);}
    :root{--blue:var(--color-mho-600);--blue-text:var(--color-mho-700);--ink:var(--color-text-primary);--muted:var(--color-text-secondary);--subtle:var(--color-text-tertiary);--line:var(--color-border);--surface:var(--color-surface);--green:var(--color-positive);--nav-active:var(--color-mho-50);--nav-active-text:var(--color-mho-600);--rail:292px;--tutor:350px;--header:64px;--radius-control:6px;--radius-nav:8px}.dark{--blue-text:var(--color-mho-400);--nav-active-text:var(--color-mho-400);--nav-active:color-mix(in srgb,var(--blue) 15%,transparent)}
    *{box-sizing:border-box}html{-webkit-font-smoothing:antialiased;scroll-behavior:smooth;-moz-osx-font-smoothing:grayscale}body{margin:0;font:14px/1.5 var(--font-sans);color:var(--ink);background:var(--color-surface-secondary)}button,input,textarea,select{font:inherit}button,a,input,textarea{-webkit-tap-highlight-color:transparent}button{cursor:pointer;transition:background-color 160ms ease,color 160ms ease,scale 160ms ease}button:active{scale:.96}button:disabled{cursor:default}a{color:var(--blue-text);text-decoration:none}button{color:inherit}h1,h2,h3,h4{font-family:var(--font-sans);font-weight:600;text-wrap:balance}p{text-wrap:pretty}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:3px solid color-mix(in srgb,var(--blue) 50%,transparent);outline-offset:3px}[hidden]{display:none!important}.icon{width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round;flex-shrink:0;vertical-align:middle}.num{font-variant-numeric:tabular-nums}.sr-only{position:absolute;width:1px;height:1px;padding:0;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}.skip{position:fixed;top:-60px;left:20px;z-index:100;background:var(--ink);color:var(--surface);padding:12px 20px;border-radius:var(--radius-control)}.skip:focus{top:10px}
    .topbar{height:var(--header);position:fixed;inset:0 0 auto;z-index:20;display:flex;align-items:center;border-bottom:0;background:var(--surface);padding:0 25px;gap:24px}.brand{font:600 20px var(--font-sans);letter-spacing:-.5px;display:flex;align-items:center;gap:10px;min-width:calc(var(--rail) - 50px)}.brand-mark{width:30px;height:30px;color:var(--blue)}.top-divider{height:22px;width:1px;background:var(--line);display:none}.back-courses{display:flex;align-items:center;gap:8px;background:transparent;border:0;font-size:12px;color:var(--muted);min-height:42px;padding:8px 0}.back-courses:hover{color:var(--blue-text)}.back-courses .icon{width:16px;height:16px}.top-spacer{flex:1}.preview-badge{font-size:11px;color:var(--muted);background:var(--color-panel);border-radius:var(--radius-control);padding:5px 8px;white-space:nowrap}.icon-button{border:0;background:transparent;width:40px;height:40px;display:flex;align-items:center;justify-content:center;border-radius:var(--radius-control);color:var(--muted)}.icon-button:hover{background:var(--surface);color:var(--ink)}.top-avatar{width:32px;height:32px;display:flex;align-items:center;justify-content:center;background:#eef2fa;border-radius:50%;color:var(--subtle)}.top-avatar .icon{width:17px;height:17px}
    .curriculum{position:fixed;top:var(--header);bottom:0;left:0;width:var(--rail);border-right:0;background:var(--surface);display:flex;flex-direction:column;z-index:10}.course-info{padding:27px 23px 22px;border-bottom:0}.course-label{font-size:10px;letter-spacing:.1em;text-transform:uppercase;color:var(--subtle);margin-bottom:8px}.course-info h2{font-size:20px;letter-spacing:-.3px;margin:0 0 16px;font-weight:700}.progress-copy{display:flex;justify-content:space-between;color:var(--muted);font-size:11px;gap:10px}.progress-copy strong{font-weight:600;color:var(--ink)}.progress-track{height:4px;background:var(--color-panel);border-radius:var(--radius-control);overflow:hidden;margin-top:9px}.progress-track span{display:block;height:100%;background:var(--blue);border-radius:var(--radius-control);transition:width 200ms ease}.module-navigation{padding:11px 11px 25px;overflow:auto;flex:1;scrollbar-width:thin;scrollbar-color:#d6dfed transparent;padding-top:0}.module-block+.module-block{margin-top:7px}.module-heading{border:0;background:transparent;border-radius:var(--radius-nav);width:100%;min-height:60px;padding:12px;display:flex;align-items:center;gap:11px;text-align:left}.module-heading:hover{background:var(--color-panel)}.module-num{font-size:11px;color:var(--subtle)}.module-heading-copy{flex:1}.module-heading-copy strong{display:block;font-size:14px;font-weight:600}.module-heading-copy small{display:block;margin-top:2px;color:var(--subtle);font-size:11px}.module-heading>.icon{width:14px;height:14px;color:var(--subtle);transition:transform 160ms ease}.module-heading[aria-expanded=true]>.icon{transform:rotate(180deg)}.module-heading.locked strong{color:var(--muted)}.step-list{display:grid;gap:3px;padding-bottom:12px}.step-button{border:0;background:transparent;padding:8px 12px;border-radius:var(--radius-nav);min-height:48px;width:100%;display:flex;gap:10px;text-align:left;align-items:flex-start;color:var(--muted);font-size:14px;line-height:1.6}.step-button:hover{background:var(--color-panel)}.step-button.current{background:var(--nav-active);color:var(--nav-active-text)}.step-button.locked{color:var(--muted)}.step-status{width:17px;min-width:17px;display:flex;align-items:center;justify-content:center;padding-top:1px;color:var(--subtle);font-size:10px}.step-status .icon{width:15px;height:15px}.step-button.complete .step-status{color:var(--green)}.step-copy{flex:1;min-width:0}.step-copy strong{font-weight:500;display:block}.step-copy small{display:block;font-size:10px;margin-top:2px;opacity:.8}.step-button.assessment{margin-top:10px;background:transparent;box-shadow:none}.step-button.assessment.current{background:var(--nav-active);box-shadow:none}.step-button.assessment.complete{box-shadow:none}.legend{padding:14px 23px;border-top:0;font-size:10px;color:var(--subtle);display:flex;gap:18px}.legend span{display:flex;align-items:center;gap:5px}.legend .icon{width:12px;height:12px}.legend .done{color:var(--green)}
    .lesson-workspace{margin:var(--header) var(--tutor) 0 var(--rail);padding:32px 36px 40px;min-height:calc(100vh - var(--header))}.lesson-breadcrumb{display:flex;align-items:center;gap:7px;flex-wrap:wrap;font-size:12px;color:var(--subtle);margin-bottom:16px}.lesson-breadcrumb .icon{width:11px;height:11px}.lesson-breadcrumb strong{font-weight:500;color:var(--muted)}.lesson-title{font-size:24px;line-height:1.25;letter-spacing:-.4px;margin:0 0 10px;font-weight:700}.lesson-meta{display:flex;align-items:center;gap:12px;flex-wrap:wrap;font-size:12px;color:var(--subtle)}.lesson-meta span{display:flex;align-items:center;gap:5px}.lesson-meta .icon{width:13px;height:13px}.lesson-meta .complete-pill{color:var(--green)}.video-surface{position:relative;margin-top:23px;aspect-ratio:16/9;border-radius:0;background:#101821;overflow:hidden;color:#fff;box-shadow:none;display:flex;align-items:center;justify-content:center}.video-surface:before{content:'';position:absolute;inset:0;background-image:radial-gradient(#aebbc51c 1px,transparent 1px);background-size:22px 22px;mask-image:radial-gradient(ellipse at center,#000,transparent 75%);display:none}.video-placeholder{text-align:center;z-index:1;padding:22px;max-width:370px}.play-circle{width:55px;height:55px;background:transparent;box-shadow:none;border-radius:50%;display:flex;align-items:center;justify-content:center;margin:0 auto 16px;color:#d4dee8}.play-circle .icon{width:22px;height:22px;margin-left:3px;fill:currentColor;stroke-width:0}.video-placeholder strong{font:500 14px var(--font-sans);display:block}.video-placeholder p{font-size:11px;color:#7f91a7;margin:7px 0 0}.video-footer{position:absolute;inset:auto 0 0;padding:15px 18px;display:flex;align-items:center;justify-content:space-between;background:linear-gradient(transparent,#070f18a0);font-size:10px;color:#8e9caf}.video-footer .icon{width:13px;height:13px}.lesson-action{display:flex;gap:12px;align-items:center;justify-content:space-between;padding:20px 0 14px;border-bottom:0}.action-copy{font-size:12px;color:var(--muted);max-width:270px;line-height:1.7}.action-copy strong{font-weight:600;color:var(--muted);display:block;margin-bottom:2px}.primary-button{border:0;display:inline-flex;justify-content:center;align-items:center;gap:8px;min-height:40px;padding:8px 16px;background:var(--blue);color:#fff;border-radius:var(--radius-control);font:500 14px var(--font-sans);white-space:nowrap}.primary-button:hover{background:var(--color-mho-700)}.primary-button .icon{width:15px;height:15px}.secondary-button{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:0;border-radius:var(--radius-control);padding:8px 16px;min-height:40px;font-size:14px;background:var(--color-secondary);color:var(--muted)}.secondary-button:hover{background:var(--color-panel)}.section-tabs{display:flex;align-items:center;gap:16px;padding-top:8px;border-bottom:0;margin-bottom:24px}.section-tab{font-size:14px;color:var(--subtle);min-height:44px;padding:8px 0;border:0;background:transparent;position:relative;display:flex;gap:7px;align-items:center;font-weight:500}.section-tab[aria-pressed=true]{color:var(--ink);font-weight:600}.section-tab[aria-pressed=true]:after{position:absolute;content:'';height:2px;left:0;right:0;bottom:-1px;background:var(--ink)}.tab-count{font-size:9px;border-radius:var(--radius-control);background:var(--color-panel);padding:1px 5px}.lesson-about h2{font-size:14px;letter-spacing:-.2px;margin:0 0 8px;font-weight:600}.lesson-about p{font-size:14px;line-height:1.65;color:var(--muted);margin:0}.practice-row{display:flex;align-items:flex-start;gap:13px;margin-top:22px;padding:0;background:transparent;border-radius:0}.practice-row>.icon{color:var(--muted);width:18px;height:18px;margin-top:2px;display:none}.practice-row h3{font-size:14px;margin:0 0 5px}.practice-row p{font-size:14px}.materials-empty{padding:8px 0 20px;background:transparent;border-radius:0;text-align:left;color:var(--muted);font-size:12px}.materials-empty .icon{width:26px;height:26px;color:#95a4b9;margin-bottom:11px;display:none}.materials-empty strong{display:block;font-size:13px;font-weight:600;color:var(--muted)}.materials-empty p{font-size:11px;margin:7px 0 0}.material-card{padding:8px 0;box-shadow:none;border-radius:0;display:flex;align-items:center;gap:12px}.material-card>.icon{width:25px;height:25px;color:var(--subtle)}.material-copy{flex:1}.material-copy strong{font-size:12px;font-weight:600;display:block}.material-copy small{font-size:10px;color:var(--subtle)}.material-card button{font-size:11px;color:var(--blue-text);min-height:40px;border:0;background:var(--nav-active);padding:8px 12px;border-radius:var(--radius-control);display:flex;gap:6px;align-items:center}.material-card button .icon{width:14px;height:14px}.lesson-footnote{margin-top:32px;color:var(--subtle);font-size:10px;display:flex;align-items:center;gap:7px}.lesson-footnote .icon{width:12px;height:12px}.mobile-toolbar{display:none}
    .tutor{position:fixed;inset:var(--header) 0 0 auto;width:var(--tutor);background:var(--surface);border-left:0;z-index:11;display:flex;flex-direction:column}.tutor-header{height:78px;padding:21px 23px;display:flex;align-items:center;gap:10px;border-bottom:0;flex-shrink:0}.ai-symbol{width:28px;height:28px;color:var(--blue)}.tutor-brand{font:600 19px var(--font-sans);letter-spacing:-.7px}.tutor-brand small{display:block;font:400 10px var(--font-sans);color:var(--subtle);letter-spacing:0;margin-top:2px}.tutor-header .icon-button{margin-left:auto}.tutor-scroll{flex:1;min-height:0;overflow:auto;padding:26px 23px;scrollbar-width:thin}.tutor-empty{padding-top:9px}.tutor-eyebrow{font:500 10px var(--font-sans);letter-spacing:.11em;text-transform:uppercase;color:var(--blue-text)}.tutor-empty h2{font:500 22px/1.4 var(--font-sans);letter-spacing:-.4px;margin:8px 0 10px;font-size:18px;font-weight:600}.tutor-empty p{color:var(--muted);font-size:14px;line-height:1.65;margin:0}.tutor-examples{margin-top:30px;display:grid;gap:4px}.tutor-examples small{color:var(--subtle);font-size:10px;padding-bottom:6px}.suggestion{padding:9px 0;min-height:42px;display:flex;align-items:center;gap:10px;text-align:left;border:0;background:transparent;font-size:13px;color:var(--muted)}.suggestion:hover{color:var(--blue-text)}.suggestion .icon{width:13px;height:13px;color:var(--blue)}.chat-message{font-size:14px;line-height:1.65;margin-bottom:23px}.chat-message.user{margin-left:14px;background:var(--color-panel);border-radius:var(--radius-control);padding:12px 14px;color:var(--muted)}.assistant-author{display:flex;align-items:center;gap:7px;font:600 11px var(--font-sans);margin-bottom:8px}.assistant-author .ai-symbol{width:17px;height:17px}.chat-message p{margin:0;color:var(--muted);white-space:pre-line}.chat-source{display:inline-flex;align-items:center;gap:5px;color:var(--blue-text);font-size:10px;min-height:40px;margin-top:6px}.chat-source .icon{width:11px;height:11px}.tutor-composer{padding:15px 17px 17px;flex-shrink:0;background:transparent}.context-chip{display:flex;gap:8px;align-items:flex-start;background:transparent;border-radius:0;padding:0 2px 10px;font-size:10px;color:var(--subtle);margin-bottom:10px}.context-chip .icon{width:13px;height:13px;margin-top:2px}.context-chip span{min-width:0}.context-chip strong{display:block;font-size:10px;color:var(--muted);line-height:1.5;font-weight:500;margin-top:3px}.composer-box{padding:12px;border-radius:var(--radius-nav);box-shadow:none;background:var(--surface);border:1px solid var(--line)}.composer-box:focus-within{box-shadow:0 0 0 2px color-mix(in srgb,var(--blue) 50%,transparent)}.composer-box textarea{resize:none;border:0;outline:0;min-height:57px;height:57px;width:100%;color:var(--ink);background:transparent;font-size:14px;line-height:1.6}.composer-box textarea::placeholder{color:var(--subtle)}.composer-actions{display:flex;justify-content:space-between;align-items:center;color:var(--subtle);font-size:9px}.send-chat{width:40px;height:40px;border:0;background:var(--blue);color:#fff;border-radius:var(--radius-control);display:flex;align-items:center;justify-content:center}.send-chat .icon{width:15px;height:15px}.tutor-demo{font-size:9px;text-align:center;color:var(--subtle);margin:10px 0 0}.tutor-mobile-close{display:none}
    .exam-intro{margin-top:24px;padding:12px 0;border-radius:0;background:transparent}.exam-symbol{width:42px;height:42px;border-radius:var(--radius-control);background:var(--nav-active);color:var(--blue);display:none;align-items:center;justify-content:center;margin-bottom:18px}.exam-intro h2{font-size:20px;letter-spacing:-.5px;margin:0 0 10px}.exam-intro p{font-size:12px;color:var(--muted);line-height:1.8;margin:0}.exam-facts{display:flex;gap:18px;margin-top:20px;font-size:11px;color:var(--muted);flex-wrap:wrap}.exam-facts span{display:flex;align-items:center;gap:6px}.exam-facts .icon{width:14px;height:14px}.question{padding:23px 0;border-bottom:0;margin:0;min-width:0;border-top:0;border-left:0;border-right:0}.question legend{font-size:12px;line-height:1.8;font-weight:600;padding-top:24px}.question-number{font-size:10px;color:var(--subtle);display:block;margin-bottom:6px}.answers{display:grid;gap:9px;margin-top:12px}.answer{display:flex;gap:10px;align-items:flex-start;padding:12px 13px;border-radius:var(--radius-control);box-shadow:none;font-size:14px;line-height:1.75;color:var(--muted);cursor:pointer;min-height:45px;background:var(--color-surface-secondary)}.answer:has(input:checked){background:var(--nav-active);box-shadow:none;color:var(--blue-text)}.answer input{accent-color:var(--blue);margin-top:4px;flex-shrink:0}.exam-submit{display:flex;gap:12px;align-items:center;justify-content:space-between;padding-top:25px}.exam-submit small{font-size:10px;color:var(--subtle)}.exam-error{font-size:12px;color:var(--color-danger);margin-top:18px}.exam-result{padding:35px 28px;text-align:center;background:color-mix(in srgb,var(--color-positive) 8%,var(--surface));border-radius:0;margin-top:25px}.exam-result.failed{background:color-mix(in srgb,var(--color-attention) 8%,var(--surface))}.result-icon{width:46px;height:46px;display:flex;justify-content:center;align-items:center;border-radius:50%;margin:auto;background:color-mix(in srgb,var(--color-positive) 12%,transparent);color:var(--green)}.exam-result.failed .result-icon{background:color-mix(in srgb,var(--color-attention) 12%,transparent);color:var(--color-attention)}.result-grade{font:600 44px var(--font-sans);letter-spacing:-2px;margin:18px 0 6px}.result-grade small{font-size:18px;color:var(--subtle);letter-spacing:-.4px}.exam-result h2{font-size:20px;margin:0 0 10px;letter-spacing:-.5px}.exam-result p{font-size:12px;color:var(--muted);line-height:1.8;margin:0 0 20px}.result-actions{display:flex;gap:10px;justify-content:center;flex-wrap:wrap}.course-dialog{border:0;padding:0;border-radius:var(--radius-nav);max-width:660px;width:calc(100% - 40px);box-shadow:var(--shadow-raise-lg);background:var(--surface);color:var(--ink)}.course-dialog::backdrop{background:#061b3166;backdrop-filter:blur(3px)}.dialog-head{padding:27px 28px 0;display:flex;justify-content:space-between;align-items:center}.dialog-head h2{font-size:24px;margin:0;letter-spacing:-.7px}.dialog-body{padding:23px 28px 28px}.dialog-description{font-size:12px;color:var(--muted);margin:0 0 24px}.course-choices{display:grid;grid-template-columns:1fr 1fr;gap:15px}.course-choice{border:0;background:transparent;border-radius:0;padding:21px;text-align:left;color:var(--ink)}.course-choice:hover{background:var(--color-panel)}.course-choice>.icon{color:var(--blue);width:28px;height:28px;margin-bottom:16px}.course-choice h3{font-size:18px;margin:0 0 7px;letter-spacing:-.5px}.course-choice p{font-size:11px;color:var(--muted);min-height:68px;margin:0 0 22px;line-height:1.7}.course-choice small{color:var(--subtle);font-size:10px}.choice-continue{display:flex;justify-content:space-between;align-items:center;color:var(--blue-text);font-size:11px;margin-top:20px}.choice-continue .icon{width:14px;height:14px}.drawer-backdrop{display:none}.toast{position:fixed;left:50%;bottom:25px;transform:translateX(-50%);background:var(--color-navy-900);color:#fff;box-shadow:0 6px 24px #061b3120;border-radius:var(--radius-control);padding:12px 18px;font-size:12px;z-index:80;max-width:calc(100vw - 36px)}
    .lesson-comments{margin-top:46px;padding-top:8px}.comments-heading{display:flex;align-items:center;gap:10px;margin-bottom:8px}.comments-heading h2{font-size:17px;letter-spacing:-.3px;margin:0}.comments-count{font-size:12px;color:var(--muted)}.comments-note{font-size:11px;color:var(--muted);margin:0 0 20px}.comment-form textarea{display:block;width:100%;min-height:90px;resize:vertical;border:1px solid var(--line);border-radius:var(--radius-control);background:var(--surface);padding:12px;font-size:14px;line-height:1.65;color:var(--ink)}.comment-form textarea::placeholder{color:var(--subtle)}.comment-form-actions{display:flex;justify-content:flex-end;gap:8px;padding-top:10px}.comment-list{margin-top:28px}.comments-empty{font-size:12px;color:var(--muted);margin:0}.comment-thread+.comment-thread{margin-top:28px}.comment-entry{display:flex;gap:12px;align-items:flex-start}.comment-avatar{width:28px;height:28px;flex-shrink:0;border-radius:50%;background:var(--blue);color:#fff;display:flex;align-items:center;justify-content:center;font-size:11px;font-weight:500}.comment-body{min-width:0;flex:1}.comment-meta{display:flex;align-items:center;gap:10px;flex-wrap:wrap;font-size:12px}.comment-meta strong{font-weight:600}.comment-meta time{font-size:10px;color:var(--subtle)}.comment-text{white-space:pre-wrap;overflow-wrap:anywhere;font-size:14px;line-height:1.65;margin:6px 0 0}.comment-actions{display:flex;gap:14px;margin-top:3px}.comment-action{border:0;background:transparent;min-height:40px;padding:6px 0;color:var(--muted);font-size:11px}.comment-action:hover{color:var(--blue-text)}.comment-replies{margin-left:40px;margin-top:9px;display:grid;gap:18px}.comment-replies:empty{display:none}.comment-reply-form{margin:12px 0 0 40px}.comment-reply-form textarea{min-height:76px}
    .profile-button{border:0;background:transparent;display:flex;align-items:center;gap:8px;padding:4px 6px;border-radius:var(--radius-nav);min-height:40px}.profile-button:hover{background:var(--color-panel)}.profile-avatar{width:28px;height:28px;background:var(--blue);color:#fff;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:12px;font-weight:500}.profile-label{font-size:13px;color:var(--ink)}.notification-button{position:relative}.notification-count{position:absolute;right:0;top:0;min-width:16px;height:16px;padding:0 4px;border-radius:8px;background:var(--blue);color:#fff;font-size:10px;line-height:16px}.menu-panel{position:fixed;top:calc(var(--header) - 5px);right:24px;width:340px;max-width:calc(100vw - 32px);background:var(--surface);color:var(--ink);border-radius:var(--radius-nav);box-shadow:var(--shadow-raise-lg);z-index:40;padding:16px}.menu-panel-head{display:flex;align-items:center;justify-content:space-between;gap:12px}.menu-panel-head h2{font-size:14px;font-weight:600;margin:0}.menu-panel-head .icon-button{width:32px;height:40px}.menu-empty{font-size:13px;color:var(--muted);margin:22px 0 12px}.notification-list{max-height:min(440px,65vh);overflow-y:auto;margin-top:8px}.notification-item{display:flex;gap:10px;width:100%;text-align:left;border:0;background:transparent;padding:12px 8px;border-radius:var(--radius-control)}.notification-item:hover{background:var(--color-surface-secondary)}.notification-item.unread{background:var(--nav-active)}.notification-dot{height:6px;width:6px;border-radius:50%;background:transparent;margin-top:7px;flex-shrink:0}.unread .notification-dot{background:var(--blue)}.notification-copy{min-width:0;flex:1}.notification-copy strong{font-size:13px;font-weight:500;display:block}.notification-copy small{font-size:11px;color:var(--muted);display:block;margin:3px 0}.notification-copy p{font-size:12px;line-height:1.5;color:var(--muted);display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;margin:6px 0}.notification-copy time{font-size:10px;color:var(--subtle);font-variant-numeric:tabular-nums}.menu-read-all{border:0;background:transparent;color:var(--blue-text);font-size:12px;min-height:40px;margin-top:8px}.profile-menu{width:280px}.profile-menu h2{font-size:14px;font-weight:600;margin:0 0 14px}.profile-menu label{display:block;font-size:12px;font-weight:500;margin:12px 0 5px}.profile-menu select{width:100%;min-height:40px;border:1px solid var(--line);border-radius:var(--radius-control);background:var(--surface);color:var(--ink);padding:8px 10px;font-size:14px}.profile-menu p{font-size:11px;color:var(--muted);line-height:1.5;margin:10px 0 14px}.profile-menu .reset-progress{font-size:12px;background:transparent;border:0;padding:8px 0;min-height:40px;color:var(--muted);display:flex;align-items:center;gap:8px}.profile-menu .reset-progress .icon{width:14px;height:14px}.visibility-label{display:inline-flex;align-items:center;gap:4px;font-size:10px;color:var(--muted)}.visibility-label .icon{width:12px;height:12px}.staff-label{font-size:10px;color:var(--blue-text)}.classification-action{color:var(--blue-text)}.comment-form-hint{margin-right:auto;color:var(--muted);font-size:11px;max-width:230px;line-height:1.5}.comment-form-actions{align-items:center}.comment-error{font-size:12px;color:var(--color-danger)}.comment-thread{scroll-margin-top:calc(var(--header) + 20px)}
    .profile-avatar,.comment-avatar{overflow:hidden;flex-shrink:0}.profile-avatar img,.comment-avatar img{width:100%;height:100%;object-fit:cover}.profile-label{max-width:160px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.profile-menu{max-height:calc(100dvh - var(--header) - 24px);overflow-y:auto}.profile-menu-summary{display:flex;align-items:center;gap:10px;margin-bottom:8px;min-width:0}.profile-menu-summary .profile-avatar{width:36px;height:36px;font-size:14px}.profile-menu-summary-copy{min-width:0;flex:1}.profile-menu-summary-copy strong{font-size:14px;font-weight:600;display:block;overflow-wrap:anywhere}.profile-menu-summary-copy small{display:block;color:var(--muted);font-size:12px;overflow-wrap:anywhere}.profile-menu-link{display:flex;gap:8px;align-items:center;width:100%;min-height:40px;border:0;background:transparent;padding:8px;border-radius:var(--radius-control);font-size:14px;text-align:left}.profile-menu-link:hover{background:var(--color-panel)}.profile-menu-link .icon{width:16px;height:16px}.profile-menu h2{font-size:11px;color:var(--muted);font-weight:500;margin:22px 0 0}.comment-author-button{border:0;background:transparent;padding:0;min-height:40px;font-size:12px;text-align:left;font-weight:600;color:var(--ink);overflow-wrap:anywhere;min-width:40px}.comment-author-button:hover{color:var(--blue-text)}.comment-avatar-button{display:flex;align-items:flex-start;justify-content:center;flex-shrink:0;width:40px;min-height:40px;border:0;background:transparent;padding:6px}.comment-entry{gap:6px}.comment-meta{column-gap:10px;row-gap:0}.comment-text{margin-top:0}.profile-dialog{max-width:500px;max-height:calc(100dvh - 40px);overflow:auto}.profile-dialog .dialog-head h2{font-size:20px;letter-spacing:-.3px}.profile-overview{display:flex;align-items:center;gap:18px;margin:8px 0 28px}.profile-overview .profile-avatar,.profile-photo-editor .profile-avatar{width:72px;height:72px;font-size:24px}.profile-overview h3{font-size:22px;line-height:1.3;margin:0;letter-spacing:-.3px;overflow-wrap:anywhere}.profile-overview p{font-size:14px;color:var(--muted);margin:6px 0 0;overflow-wrap:anywhere}.profile-details{display:grid;gap:20px;margin:0 0 30px}.profile-details dt{font-size:12px;color:var(--muted);margin-bottom:4px}.profile-details dd{font-size:14px;margin:0;overflow-wrap:anywhere}.profile-details .empty-field{color:var(--subtle)}.profile-photo-editor{display:flex;align-items:center;gap:18px;margin-bottom:24px}.profile-photo-controls{min-width:0;flex:1}.profile-photo-controls>label{display:block;font-size:12px;font-weight:500;margin-bottom:4px}.profile-photo-actions{display:flex;gap:12px;align-items:center;flex-wrap:wrap}.profile-photo-actions .secondary-button{font-size:12px}.profile-photo-remove{border:0;background:transparent;color:var(--muted);font-size:12px;min-height:40px;padding:8px 0}.profile-photo-remove:hover{color:var(--blue-text)}.profile-photo-controls small{font-size:11px;color:var(--subtle);display:block;margin-top:5px}.profile-fields{display:grid;gap:16px}.profile-field label{display:block;font-size:13px;font-weight:500;margin-bottom:6px}.profile-field input{width:100%;min-height:40px;padding:9px 12px;border:1px solid var(--line);border-radius:var(--radius-control);background:var(--surface);color:var(--ink);font-size:14px}.profile-field input::placeholder{color:var(--subtle)}.profile-form-actions{display:flex;justify-content:flex-end;gap:10px;margin-top:26px}.profile-form-note{font-size:11px;color:var(--muted);margin:20px 0 0}.profile-error{font-size:12px;color:var(--color-danger);margin:16px 0 0}.profile-photo-status{font-size:11px;color:var(--muted);margin:8px 0 0}.profile-dialog .primary-button:disabled{opacity:.65}
    @media(min-width:1600px){:root{--rail:320px;--tutor:395px}.lesson-workspace{padding:42px 48px}.lesson-title{font-size:24px;font-weight:700;letter-spacing:-.4px}.tutor-scroll{padding:33px 28px}}
    @media(max-width:1260px){:root{--rail:260px;--tutor:320px}.topbar{gap:16px}.lesson-workspace{padding:27px 25px}.course-info{padding:24px 20px}.step-button{padding-left:11px;gap:8px}.tutor-header{padding-inline:20px}.tutor-scroll{padding:24px 20px}.lesson-action{align-items:flex-start}.action-copy{font-size:12px}.primary-button{font-size:11px;padding-inline:15px;font:500 14px var(--font-sans);min-height:40px;padding:8px 16px}}
    @media(max-width:1080px){:root{--rail:274px;--tutor:350px}.lesson-workspace{margin-right:0;max-width:1000px}.tutor{transform:translateX(100%);transition:transform 180ms ease}.tutor-open .tutor{transform:translateX(0)}.tutor-open .drawer-backdrop{display:block}.drawer-backdrop{position:fixed;inset:var(--header) 0 0;background:#061b314a;z-index:9;border:0}.mobile-toolbar{display:flex;justify-content:flex-end;gap:8px;padding-bottom:20px}.mobile-toolbar button{display:flex;align-items:center;justify-content:center;gap:7px;min-height:40px;border:0;background:var(--color-panel);color:var(--muted);border-radius:var(--radius-control);padding:9px 13px;font-size:11px}.mobile-toolbar button .icon{width:15px;height:15px}.mobile-toolbar .open-lessons{display:none}.tutor-mobile-close{display:flex}.tutor-header .reset-chat{display:none}}
    @media(max-width:780px){:root{--rail:292px;--header:64px}.topbar{padding-inline:18px;gap:13px}.brand{min-width:0;font-size:21px;gap:7px}.brand-mark{width:27px;height:27px}.top-divider,.top-avatar{display:none}.back-courses{font-size:11px;margin-left:2px}.preview-badge{font-size:9px;padding:4px 6px}.topbar .icon-button{width:40px;min-width:40px;height:40px}.curriculum{transform:translateX(-100%);transition:transform 180ms ease}.nav-open .curriculum{transform:translateX(0)}.nav-open .drawer-backdrop{display:block}.lesson-workspace{margin-left:0;padding:20px 24px 35px}.mobile-toolbar{justify-content:space-between;padding-bottom:20px}.mobile-toolbar .open-lessons{display:flex}.lesson-title{font-size:24px;font-weight:700;letter-spacing:-.4px}.video-surface{margin-top:20px;border-radius:0;box-shadow:none}.course-choices{grid-template-columns:1fr}.course-choice p{min-height:0}.course-dialog{max-height:90vh}.dialog-body{padding:20px}.dialog-head{padding:20px 20px 0}.course-choice{padding:20px}.course-choice>.icon{margin-bottom:9px;width:23px;height:23px}.course-choice p{margin-bottom:14px}.choice-continue{margin-top:13px}}
    @media(max-width:490px){.back-courses span{display:none}.back-courses{padding:8px;min-height:40px}.lesson-workspace{padding:18px 18px 32px}.lesson-breadcrumb{font-size:12px;gap:5px}.lesson-title{font-size:24px;letter-spacing:-.4px;font-weight:700}.lesson-meta{font-size:12px;gap:10px}.video-surface{border-radius:0;box-shadow:none}.play-circle{width:42px;height:42px;margin-bottom:11px}.video-placeholder{padding:20px}.video-placeholder strong{font-size:12px}.video-placeholder p{font-size:10px;max-width:200px}.video-footer{font-size:9px;padding:10px 12px}.lesson-action{flex-direction:column;gap:14px;padding:19px 0 21px}.lesson-action .primary-button{width:100%;font-size:12px;min-height:40px;font:500 14px var(--font-sans);padding:8px 16px}.action-copy{font-size:12px;max-width:none}.section-tabs{gap:22px;margin-bottom:20px}.section-tab{font-size:14px;font-weight:500;min-height:44px;padding:8px 0}.practice-row{padding:0;gap:10px}.tutor{width:100%;border-left:0}.tutor-header{height:68px}.tutor-scroll{padding:20px 23px}.tutor-empty{max-width:340px}.tutor-empty h2{font-size:18px;font-weight:600}.tutor-examples{margin-top:23px}.exam-intro{padding:12px 0}.exam-intro h2{font-size:18px}.exam-submit{flex-direction:column;align-items:stretch}.exam-submit .primary-button{width:100%;font:500 14px var(--font-sans);min-height:40px;padding:8px 16px}.exam-result{padding:29px 20px}.question legend{font-size:12px}.answer{font-size:14px;background:var(--color-surface-secondary)}.material-card{padding:8px 0;gap:9px}.material-card button{padding:8px}.material-copy strong{font-size:11px}.material-copy small{font-size:9px}.toast{font-size:11px;width:max-content}.course-dialog{width:calc(100% - 28px)}}
    @media(max-width:780px){.profile-label{display:none}.topbar{gap:8px}.profile-button{padding-inline:4px}.menu-panel{right:16px}.preview-badge{display:none}.comment-form-hint{font-size:10px;max-width:200px}}
    @media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important}button:active{scale:1}}

video.lesson-video{display:block;width:100%;aspect-ratio:16/9;background:#0f172a}.chat-message p,.comment-text{white-space:pre-wrap}.student-empty{padding:8vh 25px;max-width:650px;margin:auto}.student-empty h1{font-size:28px}.student-empty p{color:var(--muted)}.busy{opacity:.65;pointer-events:none}.comment-compose textarea{width:100%;resize:vertical;min-height:90px;border:1px solid var(--line);border-radius:6px;background:var(--surface);color:var(--ink);padding:12px}.profile-form input{width:100%;padding:10px 12px;background:var(--surface);color:var(--ink);border:1px solid var(--line);border-radius:6px}.profile-form label{display:block;margin-bottom:5px}.profile-form fieldset{border:0;padding:0;margin:0 0 15px}.profile-form .profile-photo{width:72px;height:72px;object-fit:cover;border-radius:50%}.exam-result p{color:var(--muted)}.notification-item{width:100%;text-align:left}.certificate-link{display:block;margin-top:12px}.shell-error{position:fixed;bottom:15px;left:50%;transform:translateX(-50%);z-index:80;background:var(--surface);padding:12px 18px;color:var(--ink)}
.comment-intro{color:var(--muted);max-width:65ch;margin-bottom:20px}.comment-message{margin:24px 0}.comment-author{display:flex;gap:10px;align-items:center;background:transparent;border:0;padding:0;text-align:left}.comment-author strong,.comment-author small{display:block}.comment-author strong{font-size:13px}.comment-author small,.comment-message-meta{font-size:11px;color:var(--subtle)}.comment-text{margin:10px 0 6px 42px;color:var(--muted);overflow-wrap:anywhere}.comment-message-meta{margin-left:42px;display:flex;gap:15px;align-items:center}.comment-message-meta button{border:0;background:transparent;color:var(--muted);padding:4px 0}.comment-thread-head{margin-top:28px}.comment-form-footer{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:8px 0 20px}.comment-form-hint{font-size:11px;color:var(--subtle)}.comment-thread .comment-compose textarea{min-height:60px}.comment-thread .comment-compose{margin-left:42px}.secondary-button{padding:9px 14px;border:0;background:var(--nav-active);color:var(--blue-text);border-radius:6px}.tutor-answer{color:var(--muted);overflow-wrap:anywhere}.tutor-answer p{white-space:normal;margin:0 0 10px}.tutor-answer pre{white-space:pre;overflow:auto;padding:12px;background:var(--color-surface-secondary);border-radius:6px}.tutor-answer ul,.tutor-answer ol{padding-left:20px}.tutor-answer code{font-family:var(--font-mono);font-size:.88em}.no-courses .curriculum{display:none}.no-courses .lesson-workspace{margin-left:0}.no-courses .open-lessons{display:none}@media(max-width:490px){.comment-form-footer{align-items:flex-start;flex-direction:column}.comment-thread .comment-compose{margin-left:0}}

.video-surface{display:block;aspect-ratio:auto}.video-footer{position:static;background:var(--color-surface);color:var(--muted);padding:10px 0;font-size:12px}.lesson-video{display:block;width:100%;aspect-ratio:16/9;border:0}