:root{--bg-primary: #090d16;--bg-secondary: #0f172a;--bg-tertiary: #1e293b;--bg-card: rgba(15, 23, 42, .75);--bg-card-hover: rgba(30, 41, 59, .8);--bg-input: #0b1120;--border-subtle: #1e293b;--border-strong: #334155;--border-focus: #00d8ff;--text-primary: #f8fafc;--text-secondary: #94a3b8;--text-muted: #64748b;--text-inverse: #090d16;--react-cyan: #00d8ff;--react-cyan-glow: rgba(0, 216, 255, .25);--accent-blue: #3b82f6;--accent-purple: #8b5cf6;--accent-purple-glow: rgba(139, 92, 246, .3);--accent-green: #10b981;--accent-green-glow: rgba(16, 185, 129, .25);--accent-amber: #f59e0b;--accent-rose: #f43f5e;--nav-height: 60px;--sidebar-width: 320px;--drawer-width: 420px;--font-sans: "Plus Jakarta Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;--font-mono: "JetBrains Mono", "Fira Code", Menlo, Monaco, Consolas, monospace;--glass-blur: blur(12px);--shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, .3);--shadow-md: 0 4px 12px -2px rgba(0, 0, 0, .4);--shadow-lg: 0 10px 25px -3px rgba(0, 0, 0, .5);--shadow-glow: 0 0 20px var(--react-cyan-glow);--shadow-ai-glow: 0 0 25px var(--accent-purple-glow);--scrollbar-thumb: #334155;--scrollbar-track: #090d16;color-scheme:dark;scrollbar-color:var(--scrollbar-thumb) var(--scrollbar-track)}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html,body{height:100%;font-family:var(--font-sans);background-color:var(--bg-primary);color:var(--text-primary);line-height:1.5;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}#root{height:100vh;display:flex;flex-direction:column;overflow:hidden}@supports not (scrollbar-color: auto){::-webkit-scrollbar{width:8px;height:8px}::-webkit-scrollbar-track{background:var(--scrollbar-track)}::-webkit-scrollbar-thumb{background:var(--scrollbar-thumb);border-radius:4px}}.navbar{height:var(--nav-height);background:#0f172ad9;-webkit-backdrop-filter:var(--glass-blur);backdrop-filter:var(--glass-blur);border-bottom:1px solid var(--border-subtle);display:flex;align-items:center;justify-content:space-between;padding:0 20px;z-index:40}.nav-brand{display:flex;align-items:center;gap:12px;font-weight:700;font-size:1.15rem;letter-spacing:-.02em;color:var(--text-primary)}.nav-brand svg{color:var(--react-cyan);filter:drop-shadow(0 0 8px var(--react-cyan-glow));animation:spinSlow 20s linear infinite}@keyframes spinSlow{0%{transform:rotate(0)}to{transform:rotate(360deg)}}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.spin{animation:spin 1s linear infinite}.brand-badge{font-size:.65rem;text-transform:uppercase;letter-spacing:.08em;padding:2px 8px;background:#00d8ff1f;color:var(--react-cyan);border:1px solid rgba(0,216,255,.3);border-radius:9999px;font-weight:700}.nav-actions{display:flex;align-items:center;gap:16px}.progress-pill{display:flex;align-items:center;gap:10px;background:var(--bg-tertiary);padding:6px 14px;border-radius:9999px;border:1px solid var(--border-subtle);font-size:.85rem;font-weight:600}.progress-bar-inline{width:70px;height:6px;background:#ffffff1a;border-radius:3px;overflow:hidden}.progress-bar-fill{height:100%;background:linear-gradient(90deg,var(--react-cyan),var(--accent-green));transition:width .3s ease}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:8px 16px;font-size:.875rem;font-weight:600;font-family:inherit;border-radius:8px;cursor:pointer;transition:all .15s ease;border:1px solid transparent}.btn-primary{background:var(--react-cyan);color:var(--text-inverse);box-shadow:0 0 15px var(--react-cyan-glow)}.btn-primary:hover{background:#38bdf8;transform:translateY(-1px)}.btn-secondary{background:var(--bg-tertiary);color:var(--text-primary);border-color:var(--border-strong)}.btn-secondary:hover{background:#334155;border-color:#475569}.btn-ai{background:linear-gradient(135deg,#7c3aed,#9333ea);color:#fff;border:1px solid rgba(168,85,247,.4);box-shadow:0 0 16px var(--accent-purple-glow)}.btn-ai:hover{background:linear-gradient(135deg,#6d28d9,#7e22ce);box-shadow:0 0 20px #a855f780;transform:translateY(-1px)}.btn-sm{padding:5px 10px;font-size:.775rem}.btn:disabled{opacity:.5;cursor:not-allowed;transform:none!important}.app-container{display:flex;flex:1;height:calc(100vh - var(--nav-height));overflow:hidden;position:relative}.sidebar{width:var(--sidebar-width);background:var(--bg-secondary);border-right:1px solid var(--border-subtle);display:flex;flex-direction:column;overflow:hidden;flex-shrink:0;transition:width .2s ease}.sidebar-header{padding:16px;border-bottom:1px solid var(--border-subtle);display:flex;justify-content:space-between;align-items:center}.sidebar-header h3{font-size:.95rem;font-weight:700;color:var(--text-primary)}.sidebar-content{flex:1;overflow-y:auto;padding:12px}.module-item{margin-bottom:12px;border:1px solid var(--border-subtle);border-radius:8px;background:#0f172a66;overflow:hidden}.module-header{padding:10px 14px;background:#1e293b66;display:flex;align-items:center;justify-content:space-between;cursor:pointer;-webkit-user-select:none;user-select:none;font-size:.85rem;font-weight:600;color:var(--text-secondary);transition:background .15s ease}.module-header:hover{background:#33415580;color:var(--text-primary)}.lesson-list{list-style:none;padding:6px}.lesson-item{display:flex;align-items:center;gap:10px;padding:8px 10px;border-radius:6px;font-size:.825rem;color:var(--text-secondary);cursor:pointer;transition:all .15s ease;margin-bottom:2px}.lesson-item:hover{background:var(--bg-tertiary);color:var(--text-primary)}.lesson-item.active{background:#00d8ff1a;color:var(--react-cyan);border:1px solid rgba(0,216,255,.25);font-weight:600}.lesson-item.completed{color:var(--text-muted)}.lesson-item.completed .lesson-check{color:var(--accent-green)}.content-area{display:flex;flex:1;overflow:hidden}.lesson-pane{display:flex;flex-direction:column;background:var(--bg-primary);overflow-y:auto;flex-shrink:0}.lesson-inner{padding:24px}.lesson-badge{display:inline-block;font-size:.725rem;font-weight:700;text-transform:uppercase;letter-spacing:.05em;color:var(--accent-blue);margin-bottom:6px}.lesson-title{font-size:1.5rem;font-weight:800;letter-spacing:-.02em;color:#fff;margin-bottom:16px}.concept-box{background:var(--bg-secondary);border-left:3px solid var(--react-cyan);padding:16px;border-radius:0 8px 8px 0;margin-bottom:20px;font-size:.95rem;line-height:1.6}.importance-card{background:#1e293b80;border:1px dashed var(--border-strong);border-radius:8px;padding:14px;margin-bottom:24px}.importance-card h4{font-size:.85rem;color:var(--accent-amber);margin-bottom:6px;display:flex;align-items:center;gap:6px}.importance-card p{font-size:.875rem;color:var(--text-secondary)}.section-title{font-size:1rem;font-weight:700;margin:20px 0 12px;color:var(--text-primary);display:flex;align-items:center;gap:8px}.code-example-card{background:#090d16;border:1px solid var(--border-subtle);border-radius:8px;margin-bottom:16px;overflow:hidden;box-shadow:0 4px 12px #00000040}.code-example-header{display:flex;align-items:center;justify-content:space-between;padding:6px 14px;background:#111a2e;border-bottom:1px solid var(--border-subtle)}.code-example-title{font-size:.775rem;font-weight:600;color:#94a3b8;font-family:var(--font-mono)}.code-copy-btn{display:inline-flex;align-items:center;gap:5px;background:transparent;border:1px solid transparent;border-radius:4px;color:#64748b;font-size:.725rem;font-family:inherit;padding:3px 8px;cursor:pointer;transition:all .15s ease}.code-copy-btn:hover{background:#ffffff12;color:#e2e8f0}.code-example-pre{padding:14px 16px;margin:0;background:#080c14;font-family:var(--font-mono);font-size:.84rem;line-height:1.6;overflow-x:auto;-moz-tab-size:2;tab-size:2;color:#e2e8f0}.token.comment,.token.prolog,.token.doctype,.token.cdata{color:#64748b!important;font-style:italic!important}.token.punctuation{color:#94a3b8!important}.token.property,.token.tag,.token.boolean,.token.number,.token.constant,.token.symbol{color:#f43f5e!important;font-weight:500}.token.selector,.token.attr-name{color:#38bdf8!important}.token.string,.token.char,.token.builtin{color:#34d399!important}.token.operator,.token.entity,.token.url{color:#38bdf8!important}.token.atrule,.token.attr-value{color:#34d399!important}.token.keyword{color:#c084fc!important;font-weight:600}.token.function,.token.class-name{color:#60a5fa!important;font-weight:600}.token.regex,.token.important,.token.variable{color:#fb923c!important}.challenge-card{background:linear-gradient(180deg,#1e293bb3,#0f172ae6);border:1px solid var(--border-strong);border-radius:10px;padding:18px;margin-top:24px}.challenge-card h4{color:var(--accent-green);font-size:.95rem;margin-bottom:8px;display:flex;align-items:center;gap:8px}.challenge-card p{font-size:.9rem;color:var(--text-secondary);line-height:1.6}.coding-pane{flex:1;display:flex;flex-direction:column;background:#090d16;overflow:hidden}.editor-toolbar{height:44px;background:#0d131f;border-bottom:1px solid var(--border-subtle);display:flex;align-items:center;justify-content:space-between;padding:0 16px}.file-tab{display:flex;align-items:center;gap:8px;font-size:.8rem;font-family:var(--font-mono);color:var(--text-primary);font-weight:500}.toolbar-actions{display:flex;align-items:center;gap:10px}.editor-workspace{display:flex;flex-direction:column;flex:1;overflow:hidden}.monaco-container{flex:1;min-height:250px;position:relative}.bottom-dock{height:320px;border-top:1px solid var(--border-strong);display:flex;flex-direction:column;background:#0d131f}.dock-header{height:38px;background:#131b2c;display:flex;align-items:center;justify-content:space-between;padding:0 14px;border-bottom:1px solid var(--border-subtle)}.dock-tabs{display:flex;gap:4px}.dock-tab{padding:6px 14px;font-size:.8rem;font-weight:600;background:transparent;border:none;color:var(--text-secondary);cursor:pointer;border-radius:4px;display:flex;align-items:center;gap:6px;transition:all .15s ease}.dock-tab:hover{color:var(--text-primary);background:#ffffff0d}.dock-tab.active{color:var(--react-cyan);background:#00d8ff1a}.dock-content{flex:1;overflow:auto;position:relative}.preview-iframe{width:100%;height:100%;border:none;background:#fff}.test-suite{padding:16px}.test-item{display:flex;align-items:flex-start;gap:10px;padding:10px;background:var(--bg-secondary);border-radius:6px;margin-bottom:8px;font-size:.85rem;border-left:3px solid transparent}.test-item.passed{border-left-color:var(--accent-green)}.test-item.failed{border-left-color:var(--accent-rose)}.test-status-icon{margin-top:2px}.ai-drawer{position:fixed;top:var(--nav-height);right:0;width:var(--drawer-width);height:calc(100vh - var(--nav-height));background:#0f172af2;-webkit-backdrop-filter:var(--glass-blur);backdrop-filter:var(--glass-blur);border-left:1px solid var(--border-strong);box-shadow:-10px 0 30px #0009;z-index:50;display:flex;flex-direction:column;transform:translate(100%);transition:transform .25s cubic-bezier(.16,1,.3,1)}.ai-drawer.open{transform:translate(0)}.ai-header{padding:16px 20px;border-bottom:1px solid var(--border-subtle);display:flex;align-items:center;justify-content:space-between}.ai-brand{display:flex;align-items:center;gap:8px;font-weight:700;font-size:1rem;color:#fff}.ai-brand svg{color:var(--accent-purple)}.ai-tabs{display:flex;border-bottom:1px solid var(--border-subtle);padding:0 16px}.ai-tab{flex:1;text-align:center;padding:10px 0;font-size:.8rem;font-weight:600;color:var(--text-muted);cursor:pointer;border-bottom:2px solid transparent;transition:all .15s ease}.ai-tab.active{color:var(--accent-purple);border-bottom-color:var(--accent-purple)}.ai-body{flex:1;overflow-y:auto;padding:20px;display:flex;flex-direction:column;gap:16px}.chat-bubble{padding:12px 16px;border-radius:10px;font-size:.875rem;line-height:1.5;max-width:90%}.chat-bubble.user{background:var(--bg-tertiary);color:var(--text-primary);align-self:flex-end;border-bottom-right-radius:2px}.chat-bubble.mentor{background:#8b5cf61f;border:1px solid rgba(139,92,246,.3);color:#e2e8f0;align-self:flex-start;border-bottom-left-radius:2px}.ai-chat-input-bar{padding:14px;border-top:1px solid var(--border-subtle);display:flex;gap:8px}.ai-chat-input{flex:1;background:var(--bg-input);border:1px solid var(--border-strong);border-radius:6px;padding:10px 14px;color:#fff;font-family:inherit;font-size:.85rem;outline:none}.ai-chat-input:focus{border-color:var(--accent-purple)}.modal-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#000000b3;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);display:flex;align-items:center;justify-content:center;z-index:100}.modal-dialog{background:var(--bg-secondary);border:1px solid var(--border-strong);border-radius:12px;width:90%;max-width:540px;box-shadow:var(--shadow-lg);overflow:hidden;animation:modalIn .15s ease-out}@keyframes modalIn{0%{opacity:0;transform:scale(.96)}to{opacity:1;transform:scale(1)}}.modal-header{padding:18px 24px;border-bottom:1px solid var(--border-subtle);display:flex;align-items:center;justify-content:space-between}.modal-header h3{font-size:1.1rem;font-weight:700}.modal-body{padding:24px;display:flex;flex-direction:column;gap:18px}.modal-footer{padding:16px 24px;border-top:1px solid var(--border-subtle);display:flex;justify-content:flex-end;gap:12px;background:#0f172a80}.form-group{display:flex;flex-direction:column;gap:6px}.form-group label{font-size:.85rem;font-weight:600;color:var(--text-secondary)}.form-group input{background:var(--bg-input);border:1px solid var(--border-strong);border-radius:6px;padding:10px 12px;color:#fff;font-size:.875rem;font-family:inherit;outline:none}.form-group input:focus{border-color:var(--react-cyan)}.form-group small{font-size:.775rem;color:var(--text-muted)}.challenge-goal-banner{background:linear-gradient(90deg,#111a2e,#131b2c);border-bottom:1px solid var(--border-subtle);padding:8px 16px;display:flex;align-items:center;justify-content:space-between;gap:16px;flex-shrink:0}.goal-text{display:flex;align-items:center;gap:10px;overflow:hidden}.goal-tag{background:#00d8ff26;color:var(--react-cyan);border:1px solid rgba(0,216,255,.3);font-size:.7rem;font-weight:800;text-transform:uppercase;padding:2px 8px;border-radius:4px;letter-spacing:.05em;flex-shrink:0}.goal-text p{font-size:.85rem;color:#e2e8f0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;font-weight:500}.goal-status{display:flex;align-items:center;gap:10px;flex-shrink:0}.status-badge{display:flex;align-items:center;gap:6px;font-size:.775rem;font-weight:700;padding:3px 10px;border-radius:9999px}.status-badge.passed{background:#10b98126;color:var(--accent-green);border:1px solid var(--accent-green)}.status-badge.failed{background:#f43f5e26;color:var(--accent-rose);border:1px solid var(--accent-rose)}.status-badge.ready{background:#3b82f626;color:var(--accent-blue);border:1px solid rgba(59,130,246,.4)}.btn-hint-pill{background:#8b5cf633;border:1px solid rgba(139,92,246,.4);color:#c4b5fd;font-size:.75rem;font-weight:600;padding:3px 9px;border-radius:9999px;display:inline-flex;align-items:center;gap:5px;cursor:pointer;transition:all .15s ease}.btn-hint-pill:hover{background:#8b5cf659;color:#fff;box-shadow:0 0 10px var(--accent-purple-glow)}.toolbar-left-actions{display:flex;align-items:center;gap:8px}.btn-icon{display:inline-flex;align-items:center;justify-content:center;width:34px;height:34px;border-radius:8px;background:#141d2e;border:1px solid #28374f;color:#94a3b8;cursor:pointer;transition:all .15s ease;position:relative}.btn-icon:hover{background:#1e2c45;color:#f8fafc;border-color:#3b4f71;transform:translateY(-1px)}.btn-icon:active{transform:translateY(0) scale(.96)}.btn-icon.active-zap{background:#00d8ff26;color:var(--react-cyan);border-color:#00d8ff80;box-shadow:0 0 12px var(--react-cyan-glow)}.btn-icon.btn-reset:hover{color:#fb7185;border-color:#f43f5e80;background:#f43f5e26}.btn-run{background:linear-gradient(135deg,#0284c7,#00d8ff);color:#090d16;font-weight:700;box-shadow:0 0 15px var(--react-cyan-glow)}.btn-run:hover{filter:brightness(1.1);transform:translateY(-1px)}.kbd-shortcut{font-size:.65rem;background:#0000004d;padding:2px 5px;border-radius:4px;margin-left:4px;font-family:var(--font-mono)}.btn-solution{border-color:#f59e0b66;color:#fde68a}.btn-solution:hover{background:#f59e0b26;border-color:var(--accent-amber)}.editor-toast{position:absolute;top:60px;left:50%;transform:translate(-50%);background:#0f172a;border:1px solid var(--border-strong);box-shadow:var(--shadow-lg);color:#f8fafc;padding:8px 16px;border-radius:8px;font-size:.825rem;font-weight:600;display:flex;align-items:center;gap:8px;z-index:30;animation:fadeInDown .2s ease-out}@keyframes fadeInDown{0%{opacity:0;transform:translate(-50%,-10px)}to{opacity:1;transform:translate(-50%)}}.editor-statusbar{position:absolute;bottom:0;left:0;right:0;height:22px;background:#090d16;border-top:1px solid var(--border-subtle);display:flex;align-items:center;justify-content:flex-end;padding:0 16px;gap:16px;z-index:10}.status-item{font-family:var(--font-mono);font-size:.7rem;color:var(--text-muted)}.layout-split{display:flex;flex-direction:row!important}.layout-split .coding-pane{flex:1.2}.layout-split .bottom-dock{flex:1;height:auto!important;border-top:none;border-left:1px solid var(--border-strong)}.resizer{background:var(--border-subtle);position:relative;z-index:25;transition:background .15s ease,box-shadow .15s ease;-webkit-user-select:none;user-select:none;flex-shrink:0}.resizer-col{width:6px;cursor:col-resize;border-left:1px solid rgba(255,255,255,.04);border-right:1px solid rgba(0,0,0,.4)}.resizer-row{height:6px;cursor:row-resize;border-top:1px solid rgba(255,255,255,.04);border-bottom:1px solid rgba(0,0,0,.4)}.resizer:hover,.resizer.is-dragging{background:var(--react-cyan);box-shadow:0 0 10px var(--react-cyan-glow)}.resizer-handle-line{position:absolute;top:0;right:0;bottom:0;left:0}.references-card{margin-top:28px;padding-top:20px;border-top:1px dashed var(--border-strong)}.references-list{display:flex;flex-direction:column;gap:8px;margin-top:10px}.reference-link-item{display:flex;align-items:center;justify-content:space-between;padding:10px 14px;background:#0d131f;border:1px solid var(--border-subtle);border-radius:8px;text-decoration:none;color:var(--text-primary);transition:all .15s ease}.reference-link-item:hover{background:#141d2e;border-color:var(--react-cyan);transform:translate(2px)}.reference-info{display:flex;align-items:center;gap:10px;flex-wrap:wrap}.reference-title{font-size:.85rem;font-weight:600;color:#e2e8f0}.reference-link-item:hover .reference-title{color:var(--react-cyan)}.reference-type-badge{font-size:.675rem;font-weight:700;text-transform:uppercase;letter-spacing:.05em;padding:2px 7px;border-radius:4px;background:#38bdf81f;color:#38bdf8;border:1px solid rgba(56,189,248,.25)}.reference-icon{color:var(--text-muted);transition:color .15s ease;flex-shrink:0}.reference-link-item:hover .reference-icon{color:var(--react-cyan)}