:root{--bg-main: #0d111a;--bg-panel: #111827;--bg-card: #1f2937;--bg-terminal: #030712;--border-light: rgba(255, 255, 255, .08);--border-hover: #3b82f6;--accent-cyan: #3b82f6;--accent-purple: #6366f1;--accent-green: #10b981;--accent-red: #ef4444;--accent-orange: #f59e0b;--grad-primary: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);--grad-nebula: linear-gradient(135deg, #6366f1 0%, #3b82f6 100%);--grad-dark: linear-gradient(180deg, #111827 0%, #0d111a 100%);--font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;--font-mono: "JetBrains Mono", monospace;--shadow-neon: 0 4px 6px -1px rgba(0, 0, 0, .1), 0 2px 4px -1px rgba(0, 0, 0, .06);--shadow-purple: 0 10px 15px -3px rgba(0, 0, 0, .3);--transition-smooth: all .2s cubic-bezier(.4, 0, .2, 1)}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-main);background-image:radial-gradient(at 50% 0%,rgba(59,130,246,.05) 0px,transparent 50%);background-attachment:fixed;color:#e2e8f0;font-family:var(--font-sans);overflow-x:hidden;min-height:100vh;-webkit-font-smoothing:antialiased}::-webkit-scrollbar{width:8px;height:8px}::-webkit-scrollbar-track{background:var(--bg-main)}::-webkit-scrollbar-thumb{background:#ffffff1a;border-radius:4px}::-webkit-scrollbar-thumb:hover{background:var(--accent-cyan)}h1,h2,h3,h4{font-weight:600;letter-spacing:-.5px}.glass-panel{background:var(--bg-panel);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);border:1px solid var(--border-light);border-radius:12px;box-shadow:var(--shadow-neon);transition:var(--transition-smooth)}.glass-panel:hover{border-color:#ffffff1f}.app-container{display:flex;flex-direction:column;min-height:100vh}.nav-header{display:flex;justify-content:space-between;align-items:center;padding:16px 32px;background:#0d111ad9;-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);border-bottom:1px solid var(--border-light);position:sticky;top:0;z-index:100}.brand{display:flex;align-items:center;gap:10px;font-size:22px;font-weight:700;background:var(--grad-nebula);-webkit-background-clip:text;-webkit-text-fill-color:transparent;cursor:pointer}.brand svg{stroke:url(#cyan-purple-grad)}.nav-links{display:flex;gap:20px;align-items:center}.nav-button{background:transparent;border:none;color:#94a3b8;font-family:var(--font-sans);font-size:15px;font-weight:500;cursor:pointer;padding:8px 16px;border-radius:6px;transition:var(--transition-smooth)}.nav-button:hover,.nav-button.active{color:#fff;background:#ffffff0d}.nav-button.active{box-shadow:0 2px 0 0 var(--accent-cyan);border-radius:6px 6px 0 0}.btn-primary{background:var(--grad-primary);border:none;color:#fff;font-weight:600;padding:10px 20px;border-radius:6px;cursor:pointer;display:inline-flex;align-items:center;gap:8px;box-shadow:0 1px 2px #0000000d;transition:var(--transition-smooth)}.btn-primary:hover{transform:translateY(-1px);background:linear-gradient(135deg,#2563eb,#1d4ed8);box-shadow:0 4px 12px #3b82f640}.btn-secondary{background:#ffffff0a;border:1px solid var(--border-light);color:#fff;font-weight:500;padding:10px 20px;border-radius:6px;cursor:pointer;display:inline-flex;align-items:center;gap:8px;transition:var(--transition-smooth)}.btn-secondary:hover{background:#ffffff14;border-color:#ffffff26}.user-identity{display:flex;align-items:center;gap:12px}.avatar{width:36px;height:36px;border-radius:50%;background:var(--grad-nebula);display:flex;align-items:center;justify-content:center;font-weight:700;color:#fff}.auth-wrapper{display:flex;justify-content:center;align-items:center;flex:1;padding:40px 20px}.auth-card{width:100%;max-width:440px;padding:40px}.auth-title{font-size:28px;margin-bottom:8px;background:var(--grad-primary);-webkit-background-clip:text;-webkit-text-fill-color:transparent;text-align:center}.auth-subtitle{color:#64748b;text-align:center;margin-bottom:30px}.form-group{margin-bottom:20px}.form-label{display:block;font-size:14px;color:#94a3b8;margin-bottom:8px}.form-input{width:100%;background:#ffffff08;border:1px solid var(--border-light);border-radius:8px;padding:12px 16px;color:#fff;font-family:var(--font-sans);transition:var(--transition-smooth)}.form-input:focus{outline:none;border-color:var(--accent-cyan);box-shadow:0 0 10px #00e5ff26}.auth-toggle{text-align:center;margin-top:20px;font-size:14px;color:#64748b}.auth-toggle span{color:var(--accent-cyan);cursor:pointer}.dashboard-wrapper{max-width:1200px;margin:40px auto;padding:0 20px;width:100%}.dashboard-hero{display:flex;justify-content:space-between;align-items:center;margin-bottom:40px}.hero-title h2{font-size:32px;background:var(--grad-primary);-webkit-background-clip:text;-webkit-text-fill-color:transparent}.hero-title p{color:#94a3b8;margin-top:4px}.home-grid{display:grid;grid-template-columns:2fr 1fr;gap:30px}@media (max-width: 900px){.home-grid{grid-template-columns:1fr}}.challenge-list{display:flex;flex-direction:column;gap:16px}.challenge-card{padding:24px;display:flex;justify-content:space-between;align-items:center}.challenge-info h3{font-size:20px;color:#fff;margin-bottom:8px}.tag-container{display:flex;gap:8px}.tag{font-size:12px;font-weight:600;padding:4px 10px;border-radius:100px;text-transform:uppercase}.tag.easy{background:#00e67626;color:var(--accent-green)}.tag.medium{background:#ff910026;color:var(--accent-orange)}.tag.hard{background:#ff174426;color:var(--accent-red)}.sidebar-panel{padding:24px}.panel-title{font-size:18px;color:#fff;margin-bottom:20px;display:flex;align-items:center;gap:8px;border-bottom:1px solid var(--border-light);padding-bottom:12px}.leaderboard-list{display:flex;flex-direction:column;gap:12px}.leader-item{display:flex;justify-content:space-between;align-items:center;padding:10px 14px;background:var(--bg-card);border-radius:8px;border:1px solid var(--border-light)}.leader-rank{font-weight:800;color:var(--accent-cyan);width:24px}.leader-name{flex:1;font-weight:500}.leader-score{font-weight:700;color:var(--accent-green)}.workspace-wrapper{display:grid;grid-template-columns:450px 1fr;flex:1;height:calc(100vh - 73px);overflow:hidden}@media (max-width: 1100px){.workspace-wrapper{grid-template-columns:1fr;height:auto;overflow:auto}}.problem-pane{background:#0a0b1299;border-right:1px solid var(--border-light);display:flex;flex-direction:column;overflow-y:auto}.pane-tabs{display:flex;background:#0003;border-bottom:1px solid var(--border-light)}.pane-tab{flex:1;background:transparent;border:none;color:#64748b;padding:12px;font-family:var(--font-sans);font-weight:600;font-size:14px;cursor:pointer;transition:var(--transition-smooth)}.pane-tab.active{color:var(--accent-cyan);border-bottom:2px solid var(--accent-cyan);background:#ffffff05}.pane-content{padding:24px;flex:1}.problem-markdown h1{font-size:26px;margin-bottom:16px;color:#fff}.problem-markdown p{line-height:1.6;color:#cbd5e1;margin-bottom:16px}.problem-markdown pre,.problem-markdown code{background:#0000004d;font-family:var(--font-mono);border-radius:6px}.problem-markdown code{padding:2px 6px;font-size:14px;color:var(--accent-cyan)}.problem-markdown pre{padding:16px;overflow-x:auto;border:1px solid var(--border-light);margin-bottom:20px}.problem-markdown pre code{padding:0;color:#e2e8f0}.editor-pane{display:flex;flex-direction:column;height:100%}.editor-controls{display:flex;justify-content:space-between;align-items:center;padding:12px 24px;background:#0f111a;border-bottom:1px solid var(--border-light)}.control-group{display:flex;gap:12px;align-items:center}.selector{background:#ffffff0a;border:1px solid var(--border-light);border-radius:6px;padding:6px 12px;color:#fff;font-family:var(--font-sans);outline:none;font-weight:500}.selector option{background:var(--bg-main);color:#fff}.editor-workspace{flex:1;background:#0a0b10;position:relative}.code-textarea{width:100%;height:100%;background:transparent;border:none;color:#f8fafc;font-family:var(--font-mono);font-size:15px;line-height:1.5;padding:24px;resize:none;outline:none;-moz-tab-size:4;tab-size:4}.console-pane{height:250px;background:var(--bg-terminal);border-top:1px solid var(--border-light);display:flex;flex-direction:column;font-family:var(--font-mono)}.console-header{display:flex;justify-content:space-between;align-items:center;padding:8px 24px;background:#0f111a;border-bottom:1px solid var(--border-light);font-family:var(--font-sans);font-size:14px;font-weight:600}.console-body{padding:16px 24px;overflow-y:auto;flex:1;color:#94a3b8;font-size:14px}.console-body pre{margin-top:8px;white-space:pre-wrap;color:#e2e8f0}.console-success{color:var(--accent-green)}.console-error{color:var(--accent-red)}.console-warn{color:var(--accent-orange)}.status-banner{display:flex;align-items:center;gap:12px;padding:16px;border-radius:8px;margin-bottom:20px;font-weight:600}.status-banner.accepted{background:#00e6761a;color:var(--accent-green);border:1px solid rgba(0,230,118,.2)}.status-banner.wrong{background:#ff17441a;color:var(--accent-red);border:1px solid rgba(255,23,68,.2)}.status-banner.error{background:#ff91001a;color:var(--accent-orange);border:1px solid rgba(255,145,0,.2)}.ai-drawer{position:fixed;top:73px;right:0;width:460px;height:calc(100vh - 73px);background:#0e121ef2;-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border-left:1px solid 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li{margin-left:20px;margin-bottom:8px}.chat-tab-container{display:flex;flex-direction:column;height:100%}.chat-messages{flex:1;overflow-y:auto;padding:16px;display:flex;flex-direction:column;gap:16px}.chat-bubble{max-width:85%;padding:12px 16px;border-radius:12px;font-size:14px;line-height:1.5}.chat-bubble.user{background:var(--accent-purple);color:#fff;align-self:flex-end;border-bottom-right-radius:2px}.chat-bubble.model{background:var(--bg-card);border:1px solid var(--border-light);color:#e2e8f0;align-self:flex-start;border-bottom-left-radius:2px}.chat-code-block-container{background:#0006;border:1px solid var(--border-light);border-radius:8px;overflow:hidden;box-shadow:0 4px 12px #0003;margin-top:8px}.chat-code-block-header{display:flex;justify-content:space-between;align-items:center;padding:6px 12px;background:#ffffff08;border-bottom:1px solid 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h5{font-size:13px;color:#94a3b8;margin-bottom:6px;text-transform:uppercase}.complexity-value{font-size:24px;font-weight:800;color:var(--accent-cyan);font-family:var(--font-mono)}.complexity-optimal{font-size:12px;color:var(--accent-green);margin-top:4px}.loader-spinner{width:40px;height:40px;border:3px solid rgba(59,130,246,.1);border-top-color:var(--accent-cyan);border-radius:50%;animation:spin 1s infinite linear}@keyframes spin{to{transform:rotate(360deg)}}.pulse-glow{animation:pulse 2s infinite ease-in-out}@keyframes pulse{0%{opacity:.85}50%{opacity:1;filter:drop-shadow(0 0 6px rgba(59,130,246,.45))}to{opacity:.85}}