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td{background:#ffd7001a}.leaderboard-table tr.rank-2 td{background:#c0c0c01a}.leaderboard-table tr.rank-3 td{background:#cd7f321a}.no-leaderboard{text-align:center;color:var(--text-secondary);padding:32px}@media (width<=640px){.profile-card{padding:20px}.profile-stats{grid-template-columns:repeat(2,1fr)}.profile-tabs{overflow-x:auto}.tab-btn{white-space:nowrap;padding:8px 12px;font-size:13px}.badges-grid{grid-template-columns:repeat(2,1fr)}.leaderboard-table{font-size:12px}.leaderboard-table th,.leaderboard-table td{padding:8px 6px}}.landing-page{min-height:calc(100vh - 56px)}.landing-hero{background:linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);padding:80px 0 60px}.landing-hero .container{grid-template-columns:1fr 1fr;align-items:center;gap:60px;display:grid}.hero-content h1{margin-bottom:20px;font-size:48px;font-weight:800;line-height:1.1}.highlight{color:var(--accent)}.hero-subtitle{color:var(--text-secondary);max-width:520px;margin-bottom:32px;font-size:18px;line-height:1.6}.landing-actions{gap:16px;display:flex}.btn-lg{padding:14px 28px;font-size:16px;font-weight:600}.hero-visual{justify-content:center;display:flex}.code-preview{background:var(--bg-card);border-radius:12px;width:100%;max-width:440px;overflow:hidden;box-shadow:0 20px 40px #0000004d}.code-header{background:var(--bg-secondary);border-bottom:1px solid var(--border);align-items:center;gap:8px;padding:12px 16px;display:flex}.dot{border-radius:50%;width:12px;height:12px}.dot.red{background:#ff5f56}.dot.yellow{background:#ffbd2e}.dot.green{background:#27ca40}.filename{color:var(--text-muted);margin-left:8px;font-size:13px}.code-content{color:var(--text-primary);margin:0;padding:20px;font-family:Monaco,Menlo,monospace;font-size:13px;line-height:1.6;overflow-x:auto}.code-result{align-items:center;gap:8px;padding:12px 16px;font-size:14px;font-weight:500;display:flex}.code-result.success{color:var(--green);background:#2ecc711a;border-top:1px solid #2ecc7133}.code-result .icon{font-size:16px}.landing-stats{background:var(--bg-secondary);border-top:1px solid var(--border);border-bottom:1px solid var(--border);padding:60px 0}.stats-grid{text-align:center;grid-template-columns:repeat(4,1fr);gap:32px;display:grid}.landing-stat{flex-direction:column;gap:8px;display:flex}.landing-stat .value{color:var(--accent);font-size:42px;font-weight:800}.landing-stat .label{color:var(--text-secondary);text-transform:uppercase;letter-spacing:.5px;font-size:14px}.landing-features{padding:80px 0}.section-title{text-align:center;margin-bottom:48px;font-size:36px;font-weight:700}.features-grid{grid-template-columns:repeat(3,1fr);gap:24px;display:grid}.feature-card{text-align:center;padding:32px;transition:transform .2s,box-shadow .2s}.feature-card:hover{transform:translateY(-4px);box-shadow:0 12px 24px #00000026}.feature-icon{margin-bottom:16px;font-size:40px}.feature-card h3{color:var(--text-primary);margin-bottom:12px;font-size:20px;font-weight:600}.feature-card p{color:var(--text-secondary);font-size:14px;line-height:1.6}.landing-difficulty{background:var(--bg-secondary);padding:80px 0}.difficulty-grid{grid-template-columns:repeat(3,1fr);gap:24px;display:grid}.difficulty-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:28px;transition:transform .2s}.difficulty-card:hover{transform:translateY(-4px)}.difficulty-card.easy{border-top:3px solid var(--green)}.difficulty-card.medium{border-top:3px solid var(--yellow)}.difficulty-card.hard{border-top:3px solid var(--red)}.difficulty-header{justify-content:space-between;align-items:center;margin-bottom:16px;display:flex}.difficulty-header .count{color:var(--text-muted);font-size:13px}.difficulty-card>p{color:var(--text-secondary);margin-bottom:16px;font-size:14px;line-height:1.5}.topics{margin:0;padding:0;list-style:none}.topics li{color:var(--text-muted);border-top:1px solid var(--border);padding:6px 0;font-size:13px}.topics li:first-child{border-top:none}.landing-cta{text-align:center;padding:80px 0}.cta-content h2{margin-bottom:16px;font-size:32px;font-weight:700}.cta-content p{color:var(--text-secondary);margin-bottom:32px;font-size:18px}.landing-footer{border-top:1px solid var(--border);text-align:center;padding:24px 0}.landing-footer p{color:var(--text-muted);font-size:14px}@media (width<=1024px){.landing-hero .container{text-align:center;grid-template-columns:1fr}.hero-subtitle{margin:0 auto 32px}.landing-actions{justify-content:center}.hero-visual{display:none}.features-grid,.difficulty-grid{grid-template-columns:1fr;max-width:500px;margin:0 auto}.stats-grid{grid-template-columns:repeat(2,1fr)}}@media (width<=600px){.hero-content h1{font-size:32px}.section-title{font-size:28px}.stats-grid{grid-template-columns:1fr 1fr;gap:20px}.landing-stat .value{font-size:32px}.landing-actions{flex-direction:column}}.mobile-landing-page{justify-content:center;align-items:center;min-height:calc(100vh - 56px);padding:24px;display:flex}.mobile-landing-content{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius-lg);width:100%;max-width:620px;padding:28px}.mobile-landing-content h1{margin-bottom:8px}.mobile-landing-content p{color:var(--text-secondary)}.mobile-feature-list{gap:10px;margin:18px 0;display:grid}.mobile-feature{background:var(--bg-input);border:1px solid var(--border);border-radius:var(--radius);padding:10px 12px}.mobile-note{color:var(--accent);font-size:13px}.mobile-actions{flex-wrap:wrap;gap:10px;margin-top:16px;display:flex}main{padding-top:20px;padding-bottom:40px}:root{--bg-primary:#1a1a2e;--bg-secondary:#16213e;--bg-card:#1e2a4a;--bg-input:#0f1729;--bg-hover:#253458;--text-primary:#e2e8f0;--text-secondary:#94a3b8;--text-muted:#64748b;--accent:#f59e0b;--accent-hover:#d97706;--green:#22c55e;--green-bg:#22c55e1a;--yellow:#eab308;--yellow-bg:#eab3081a;--red:#ef4444;--red-bg:#ef44441a;--blue:#3b82f6;--blue-bg:#3b82f61a;--border:#2d3748;--border-light:#374151;--shadow:0 4px 6px -1px #0000004d;--radius:8px;--radius-lg:12px}*{box-sizing:border-box;margin:0;padding:0}body{background:var(--bg-primary);color:var(--text-primary);min-height:100vh;font-family:Inter,system-ui,-apple-system,sans-serif;line-height:1.6}#root{flex-direction:column;min-height:100vh;display:flex}a{color:var(--accent);text-decoration:none;transition:color .2s}a:hover{color:var(--accent-hover)}button{cursor:pointer;font-family:inherit}input,select,textarea{font-family:inherit}::-webkit-scrollbar{width:8px;height:8px}::-webkit-scrollbar-track{background:var(--bg-primary)}::-webkit-scrollbar-thumb{background:var(--border);border-radius:4px}::-webkit-scrollbar-thumb:hover{background:var(--border-light)}.container{max-width:1200px;margin:0 auto;padding:0 24px}.badge{text-transform:capitalize;border-radius:20px;align-items:center;padding:2px 10px;font-size:12px;font-weight:600;display:inline-flex}.badge-easy{background:var(--green-bg);color:var(--green)}.badge-medium{background:var(--yellow-bg);color:var(--yellow)}.badge-hard{background:var(--red-bg);color:var(--red)}.btn{border-radius:var(--radius);border:none;align-items:center;gap:8px;padding:10px 20px;font-size:14px;font-weight:600;transition:all .2s;display:inline-flex}.btn-primary{background:var(--accent);color:#000}.btn-primary:hover{background:var(--accent-hover)}.btn-primary:disabled{opacity:.5;cursor:not-allowed}.btn-secondary{background:var(--bg-hover);color:var(--text-primary);border:1px solid var(--border)}.btn-secondary:hover{background:var(--border)}.btn-success{background:var(--green);color:#000}.btn-success:hover{background:#16a34a}.btn-danger{background:var(--red);color:#fff}.btn-danger:hover{background:#dc2626}.btn-outline{color:var(--text-secondary);border:1px solid var(--border);background:0 0}.btn-outline:hover{background:var(--bg-hover);color:var(--text-primary)}.btn-outline:disabled{opacity:.5;cursor:not-allowed}.input{background:var(--bg-input);border:1px solid var(--border);border-radius:var(--radius);width:100%;color:var(--text-primary);padding:10px 14px;font-size:14px;transition:border-color .2s}.input:focus{border-color:var(--accent);outline:none}.input::placeholder{color:var(--text-muted)}.card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius-lg);overflow:hidden}.loading{color:var(--text-secondary);justify-content:center;align-items:center;padding:60px;display:flex}.spinner{border:3px solid var(--border);border-top-color:var(--accent);border-radius:50%;width:32px;height:32px;animation:.8s linear infinite spin}@keyframes spin{to{transform:rotate(360deg)}}