:root{--bg-dark: #050810;--bg-card: rgba(12, 16, 28, .85);--bg-card-hover: rgba(18, 24, 42, .9);--border-dim: rgba(255, 255, 255, .08);--border-glow: rgba(0, 242, 254, .4);--accent-cyan: #00f2fe;--accent-blue: #4facfe;--accent-purple: #a855f7;--accent-pink: #e100ff;--accent-green: #00f2c3;--accent-red: #ff416c;--accent-gold: #ffd700;--accent-orange: #ff8c00;--text-main: #f0f4ff;--text-muted: #7888aa;--font-sans: "Outfit", system-ui, sans-serif;--font-mono: "JetBrains Mono", monospace}*{box-sizing:border-box;margin:0;padding:0}body{font-family:var(--font-sans);background:var(--bg-dark);color:var(--text-main);overflow-x:hidden;min-height:100vh}body:before{content:"";position:fixed;top:0;left:0;right:0;bottom:0;background:radial-gradient(circle at 50% 0%,rgba(0,242,254,.05) 0%,transparent 70%),radial-gradient(circle at 100% 100%,rgba(168,85,247,.05) 0%,transparent 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#0009;animation:borderGlow 4s infinite alternate,fadeInUp .5s ease-out}.auth-logo{text-align:center;margin-bottom:2rem}.auth-logo-icon{font-size:3rem;display:block;margin-bottom:.5rem}.auth-title{font-size:2rem;font-weight:800;background:linear-gradient(to right,var(--accent-cyan),var(--accent-blue));-webkit-background-clip:text;-webkit-text-fill-color:transparent;margin:0}.auth-subtitle{color:var(--text-muted);font-size:.9rem;margin-top:.25rem}.auth-tabs{display:flex;background:#0006;border-radius:10px;padding:4px;margin-bottom:1.5rem;border:1px solid var(--border-dim)}.auth-tab{flex:1;background:transparent;border:none;color:var(--text-muted);padding:.6rem;font-weight:600;border-radius:8px;cursor:pointer;transition:all .3s}.auth-tab.active{background:#ffffff1a;color:var(--text-main);box-shadow:0 2px 8px #0000004d}.auth-form{display:flex;flex-direction:column;gap:1.2rem}.auth-field{display:flex;flex-direction:column;gap:.4rem}.auth-label{font-size:.85rem;color:var(--text-muted);font-weight:600}.auth-submit{width:100%;margin-top:.5rem}.auth-error{background:#ff416c26;border:1px solid var(--accent-red);color:#ff8a9e;padding:.75rem 1rem;border-radius:8px;font-size:.9rem;text-align:center}.auth-footer{text-align:center;font-size:.9rem;color:var(--text-muted);margin-top:1.5rem}.auth-link{background:none;border:none;color:var(--accent-cyan);font-weight:600;cursor:pointer;text-decoration:underline}.auth-features{display:flex;flex-wrap:wrap;gap:.5rem 1rem;justify-content:center;margin-top:1.5rem;padding-top:1.5rem;border-top:1px solid var(--border-dim);font-size:.78rem;color:var(--text-muted)}.auth-spinner{display:inline-block;width:20px;height:20px;border:3px solid rgba(0,0,0,.2);border-top-color:#000;border-radius:50%;animation:spin .8s linear infinite}.profile-modal-card{position:relative;max-height:85vh;overflow-y:auto}.profile-close-btn{position:absolute;top:1rem;right:1rem;background:none;border:none;color:var(--text-muted);font-size:1.5rem;cursor:pointer}.profile-close-btn:hover{color:var(--text-main)}.profile-header{margin-bottom:1.5rem}.profile-tier-tag{font-size:.95rem;font-weight:700}.profile-stats-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:.8rem;margin-bottom:1.5rem}.profile-stat-box{background:#0006;border:1px solid var(--border-dim);border-radius:10px;padding:.8rem;text-align:center}.profile-stat-box .label{display:block;font-size:.75rem;color:var(--text-muted);margin-bottom:.3rem}.profile-stat-box .value{font-size:1.1rem;font-weight:800}.profile-section{margin-bottom:1.2rem;border-top:1px solid var(--border-dim);padding-top:1rem}.profile-section-title{font-size:.95rem;margin:0 0 .8rem;color:var(--text-main)}.profile-badges-list{display:flex;flex-wrap:wrap;gap:.5rem}.achievement-badge{background:#a855f726;border:1px solid var(--accent-purple);color:var(--accent-purple);padding:.4rem .8rem;border-radius:20px;font-size:.82rem;font-weight:600}.weakness-bars{display:flex;flex-direction:column;gap:.6rem}.progress-bar-track{height:6px;background:#0006;border-radius:3px;overflow:hidden}.progress-bar-fill{height:100%;border-radius:3px;transition:width .5s ease}.profile-match-list{display:flex;flex-direction:column;gap:.4rem;max-height:120px;overflow-y:auto}.profile-match-item{display:flex;justify-content:space-between;padding:.5rem .8rem;border-radius:6px;font-size:.82rem;background:#0000004d}.profile-match-item.win{border-left:3px solid var(--accent-green)}.profile-match-item.loss{border-left:3px solid var(--accent-red)}.sandbox-output-drawer{background:#0009;border:1px solid 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1.5rem;max-width:680px;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}.nav-tab{flex:1;background:transparent;border:none;color:var(--text-muted);font-family:var(--font-sans);font-weight:600;font-size:.95rem;padding:.6rem 1rem;border-radius:20px;cursor:pointer;transition:all .3s;white-space:nowrap}.nav-tab.active{background:linear-gradient(135deg,#00f2fe33,#4facfe33);color:var(--accent-cyan);border:1px solid var(--accent-cyan);box-shadow:0 0 15px #00f2fe33}.problem-bank-container{background:var(--bg-card);border:1px solid var(--border-dim);border-radius:16px;padding:2rem;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}.problem-bank-filters{display:flex;flex-wrap:wrap;gap:1rem;align-items:center;margin:1.5rem 0;padding:1rem;background:#0000004d;border-radius:12px;border:1px solid var(--border-dim)}.filter-group{display:flex;gap:.4rem;flex-wrap:wrap}.filter-pill{background:#ffffff0d;border:1px solid var(--border-dim);color:var(--text-muted);padding:.4rem 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var(--accent-cyan)}.rec-item-card{margin-bottom:1rem;border-left:4px solid var(--accent-purple);transition:transform .2s}.rec-item-card:hover{transform:translateY(-2px)}.daily-challenge-card{background:linear-gradient(135deg,#ffd7001a,#ff8c0026);border:1px solid var(--accent-gold);border-radius:16px;padding:1.5rem 2rem;margin-bottom:2rem;display:flex;justify-content:space-between;align-items:center;gap:1.5rem;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);box-shadow:0 10px 30px #ffd7001a;animation:borderGlow 4s infinite alternate}@media (max-width: 750px){.daily-challenge-card{flex-direction:column;text-align:center}}.daily-tag-row{display:flex;gap:.6rem;align-items:center;margin-bottom:.5rem;flex-wrap:wrap}.daily-badge{background:var(--accent-gold);color:#000;font-weight:800;font-size:.75rem;padding:.25rem .6rem;border-radius:12px}.daily-bonus{background:#00f2c333;color:var(--accent-green);font-weight:700;font-size:.78rem;padding:.25rem .6rem;border-radius:12px}.daily-date{color:var(--text-muted);font-size:.8rem}.daily-title{margin:0 0 .3rem;font-size:1.3rem;color:var(--text-main)}.daily-prompt{margin:0;color:var(--text-muted);font-size:.88rem}.daily-btn{white-space:nowrap;padding:.75rem 1.5rem;font-size:.95rem}.tournament-modal-card{max-height:85vh;overflow-y:auto}.tournament-list-item{display:flex;justify-content:space-between;align-items:center;padding:1rem;background:#0000004d;border:1px solid var(--border-dim);border-radius:10px}.bracket-tree-container{display:flex;gap:1.5rem;overflow-x:auto;padding:1rem 0}.bracket-round{flex:1;min-width:180px;display:flex;flex-direction:column}.bracket-round-title{text-align:center;color:var(--accent-cyan);font-size:.9rem;margin-bottom:1rem;text-transform:uppercase;letter-spacing:1px}.bracket-matches{display:flex;flex-direction:column;justify-content:space-around;flex:1;gap:1rem}.bracket-match-box{background:#00000080;border:1px solid var(--border-dim);border-radius:8px;padding:.6rem}.bracket-player{display:flex;justify-content:space-between;padding:.3rem .5rem;border-radius:4px;font-size:.85rem;color:var(--text-muted)}.bracket-player.winner{background:#00f2c326;color:var(--accent-green);font-weight:700}.bracket-vs{font-size:.65rem;text-align:center;color:var(--text-muted);margin:2px 0}.home-page-container{display:flex;flex-direction:column;gap:3rem;padding-bottom:3rem}.hero-section{text-align:center;padding:3rem 1rem 2rem;background:radial-gradient(circle at center,rgba(0,242,254,.1) 0%,transparent 70%)}.hero-badge{display:inline-block;background:#00f2fe26;border:1px solid var(--accent-cyan);color:var(--accent-cyan);font-size:.82rem;font-weight:700;padding:.35rem 1rem;border-radius:20px;letter-spacing:1px;margin-bottom:1.5rem;animation:pulse 3s infinite}.hero-title{font-size:3.2rem;font-weight:900;line-height:1.15;margin:0 0 1.2rem}@media (max-width: 750px){.hero-title{font-size:2.2rem}}.hero-gradient-text{background:linear-gradient(135deg,var(--accent-cyan),var(--accent-purple),var(--accent-gold));-webkit-background-clip:text;-webkit-text-fill-color:transparent}.hero-subtitle{font-size:1.15rem;color:var(--text-muted);max-width:680px;margin:0 auto 2.5rem;line-height:1.6}.hero-cta-group{display:flex;gap:1rem;justify-content:center;flex-wrap:wrap}.hero-btn{padding:.9rem 1.8rem;font-size:1rem}.stats-bar{display:grid;grid-template-columns:repeat(4,1fr);gap:1rem;background:var(--bg-card);border:1px solid var(--border-dim);border-radius:16px;padding:1.8rem;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}@media (max-width: 750px){.stats-bar{grid-template-columns:repeat(2,1fr)}}.stat-item{text-align:center}.stat-number{display:block;font-size:2rem;font-weight:900;color:var(--accent-cyan)}.stat-label{font-size:.85rem;color:var(--text-muted);margin-top:.2rem}.home-section{text-align:center}.section-heading{font-size:2rem;font-weight:800;margin-bottom:2rem}.feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:1.5rem}@media (max-width: 850px){.feature-grid{grid-template-columns:repeat(2,1fr)}}@media (max-width: 550px){.feature-grid{grid-template-columns:1fr}}.feature-card{background:var(--bg-card);border:1px solid var(--border-dim);border-radius:16px;padding:2rem 1.5rem;text-align:left;cursor:pointer;transition:all .3s;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);display:flex;flex-direction:column}.feature-card:hover{transform:translateY(-5px);border-color:var(--accent-cyan);box-shadow:0 10px 30px #00f2fe26}.feature-icon{font-size:2.5rem;margin-bottom:1rem}.feature-card h3{font-size:1.25rem;margin:0 0 .5rem}.feature-card p{color:var(--text-muted);font-size:.9rem;line-height:1.5;margin:0 0 1.2rem;flex:1}.feature-link{font-size:.85rem;font-weight:700;color:var(--accent-cyan)}.steps-container{display:grid;grid-template-columns:repeat(4,1fr);gap:1.2rem}@media (max-width: 750px){.steps-container{grid-template-columns:repeat(2,1fr)}}.step-box{background:#0006;border:1px solid var(--border-dim);border-radius:12px;padding:1.5rem;text-align:center;position:relative}.step-number{display:inline-block;width:36px;height:36px;line-height:36px;border-radius:50%;background:var(--accent-cyan);color:#000;font-weight:900;font-size:1.1rem;margin-bottom:.8rem}.step-box h4{margin:0 0 .4rem;font-size:1.05rem}.step-box p{margin:0;color:var(--text-muted);font-size:.85rem;line-height:1.4}.dual-arena-logo{display:inline-flex;align-items:center;gap:.8rem;-webkit-user-select:none;user-select:none;transition:transform .3s cubic-bezier(.175,.885,.32,1.275)}.dual-arena-logo:hover{transform:scale(1.03)}.logo-emblem-wrapper{position:relative;display:flex;align-items:center;justify-content:center}.logo-glow-ring{position:absolute;top:-4px;left:-4px;right:-4px;bottom:-4px;border-radius:50%;background:conic-gradient(from 0deg,var(--accent-cyan),var(--accent-pink),var(--accent-purple),var(--accent-cyan));filter:blur(8px);opacity:.7;animation:logoSpinRing 8s linear infinite;z-index:0}.logo-icon{position:relative;z-index:1;filter:drop-shadow(0 0 10px rgba(0,243,255,.8));display:inline-block;animation:logoPulseIcon 3s ease-in-out infinite}.logo-text{font-family:var(--font-sans);font-weight:900;letter-spacing:-.5px;background:linear-gradient(135deg,#ffffff 0%,#d0e0ff 50%,var(--accent-cyan) 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;filter:drop-shadow(0 0 12px rgba(0,243,255,.35))}.logo-text-accent{background:linear-gradient(135deg,var(--accent-cyan) 0%,var(--accent-pink) 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;margin-left:2px}@keyframes logoSpinRing{0%{transform:rotate(0)}to{transform:rotate(360deg)}}@keyframes logoPulseIcon{0%,to{transform:scale(1);filter:drop-shadow(0 0 10px rgba(0,243,255,.8))}50%{transform:scale(1.08);filter:drop-shadow(0 0 20px rgba(255,0,127,.9))}}.lobby-container,.leaderboard-container,.problem-bank-container,.learning-hub-container,.auth-card{background:var(--bg-card)!important;-webkit-backdrop-filter:blur(16px)!important;backdrop-filter:blur(16px)!important;border:1px solid rgba(0,243,255,.15)!important;box-shadow:0 12px 40px #0009,inset 0 1px #ffffff1a!important}.auth-card{border-radius:20px!important}.btn-primary{background:linear-gradient(135deg,var(--accent-cyan) 0%,var(--accent-blue) 100%)!important;color:#040711!important;font-weight:800!important;box-shadow:0 4px 20px #00f3ff59!important;transition:all .25s ease-out!important}.btn-primary:hover{transform:translateY(-2px)!important;box-shadow:0 8px 30px #00f3ff99!important}.btn-solo{background:linear-gradient(135deg,var(--accent-pink) 0%,var(--accent-purple) 100%)!important;color:#fff!important;font-weight:800!important;box-shadow:0 4px 20px #ff007f66!important;transition:all .25s ease-out!important}.btn-solo:hover{transform:translateY(-2px)!important;box-shadow:0 8px 30px #ff007fb3!important}