@import"https://fonts.googleapis.com/css2?family=Outfit:wght@400;500;600;700;800&display=swap";:root{--primary: #7c3aed;--primary-dark: #6d28d9;--primary-light: #a78bfa;--primary-subtle: rgba(124, 58, 237, .1);--secondary: #06b6d4;--accent: #f472b6;--bg-base: #0f0f14;--bg-elevated: #18181f;--bg-surface: #1f1f28;--bg-hover: #2a2a36;--text-primary: #f4f4f5;--text-secondary: #a1a1aa;--text-muted: #71717a;--border: rgba(255, 255, 255, .08);--border-hover: rgba(255, 255, 255, .15);--success: #22c55e;--warning: #eab308;--error: #ef4444;--info: #3b82f6;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .4);--shadow-md: 0 4px 12px rgba(0, 0, 0, .5);--shadow-lg: 0 8px 24px rgba(0, 0, 0, .6);--shadow-glow: 0 0 24px rgba(124, 58, 237, .25);--radius-sm: 6px;--radius-md: 10px;--radius-lg: 16px;--radius-xl: 24px;--transition-fast: .15s ease;--transition-base: .25s ease;--font-main: "Outfit", -apple-system, BlinkMacSystemFont, sans-serif}*,*:before,*:after{margin:0;padding:0;box-sizing:border-box}html{font-size:16px;scroll-behavior:smooth}body{font-family:var(--font-main);background:var(--bg-base);color:var(--text-primary);line-height:1.6;min-height:100vh;-webkit-font-smoothing:antialiased}#root{min-height:100vh;display:flex;flex-direction:column}a{color:var(--primary-light);text-decoration:none;transition:color var(--transition-fast)}a:hover{color:var(--primary)}h1,h2,h3,h4,h5,h6{font-weight:700;line-height:1.3;color:var(--text-primary)}h1{font-size:2rem;letter-spacing:-.02em}h2{font-size:1.5rem}h3{font-size:1.25rem}h4{font-size:1.1rem}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:10px 20px;border:none;border-radius:var(--radius-md);font-size:.9rem;font-weight:600;cursor:pointer;transition:all var(--transition-base);text-decoration:none;white-space:nowrap}.btn-primary{background:var(--primary);color:#fff}.btn-primary:hover{background:var(--primary-dark);transform:translateY(-1px);box-shadow:var(--shadow-glow)}.btn-secondary{background:var(--bg-surface);color:var(--text-primary);border:1px solid var(--border)}.btn-secondary:hover{background:var(--bg-hover);border-color:var(--border-hover)}.btn-success{background:var(--success);color:#fff}.btn-success:hover{filter:brightness(1.1)}.btn-danger{background:var(--error);color:#fff}.btn-danger:hover{filter:brightness(1.1)}.btn-sm{padding:6px 12px;font-size:.8rem}.btn-lg{padding:14px 28px;font-size:1rem}.btn:disabled{opacity:.5;cursor:not-allowed;transform:none!important}.form-group{margin-bottom:16px}.form-label{display:block;margin-bottom:6px;font-weight:500;font-size:.9rem;color:var(--text-secondary)}.form-input{width:100%;padding:10px 14px;background:var(--bg-surface);border:1px solid var(--border);border-radius:var(--radius-md);color:var(--text-primary);font-size:.95rem;transition:all var(--transition-base)}.form-input:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-subtle)}.form-input::placeholder{color:var(--text-muted)}.card{background:var(--bg-elevated);border-radius:var(--radius-lg);padding:24px;border:1px solid var(--border);transition:all var(--transition-base)}.card:hover{border-color:var(--border-hover)}.flashcard-container{perspective:1000px;width:100%;max-width:560px;height:320px;margin:0 auto}.flashcard{width:100%;height:100%;position:relative;transform-style:preserve-3d;transition:transform .5s cubic-bezier(.4,0,.2,1);cursor:pointer;transform-origin:center center}.flashcard.flipped{transform:rotateY(180deg)}.flashcard-face{position:absolute;left:0;top:0;width:100%;height:100%;backface-visibility:hidden;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:40px;border-radius:var(--radius-xl);text-align:center}.flashcard-front{background:linear-gradient(135deg,var(--primary) 0%,var(--primary-dark) 100%);color:#fff;box-shadow:var(--shadow-lg)}.flashcard-back{background:var(--bg-elevated);border:2px solid var(--primary);color:var(--text-primary);transform:rotateY(180deg)}.flashcard-label{font-size:.75rem;text-transform:uppercase;letter-spacing:.1em;opacity:.7;margin-bottom:16px}.flashcard-content{font-size:1.5rem;font-weight:600;line-height:1.4;text-align:center;width:100%}.flashcard-actions{position:absolute;bottom:16px;right:16px;display:flex;gap:8px}.flashcard-action-btn{width:40px;height:40px;border-radius:var(--radius-md);border:none;background:#ffffff26;color:inherit;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all var(--transition-fast);-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}.flashcard-action-btn:hover{background:#ffffff40;transform:scale(1.05)}.flashcard-action-btn.active{background:#ffffff59;animation:pulse 1s infinite}@keyframes pulse{0%,to{opacity:1}50%{opacity:.6}}.flashcard-back .flashcard-action-btn{background:var(--primary-subtle);color:var(--primary)}.flashcard-back .flashcard-action-btn:hover{background:#7c3aed40}.navbar{display:flex;align-items:center;justify-content:space-between;padding:16px 32px;background:#0f0f14f2;-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:100}.navbar-brand{font-size:1.25rem;font-weight:800;color:var(--text-primary);letter-spacing:-.02em}.navbar-brand span{color:var(--primary)}.navbar-nav{display:flex;align-items:center;gap:24px;list-style:none}.navbar-nav a{color:var(--text-secondary);font-weight:500;font-size:1rem;transition:color var(--transition-fast)}.navbar-nav a:hover{color:var(--text-primary)}.navbar-user{color:var(--text-muted);font-size:.875rem}.container{max-width:1100px;margin:0 auto;padding:0 24px}.page{padding:40px 0;flex:1}.page-header{margin-bottom:32px}.page-title{font-size:1.75rem;font-weight:700}.grid{display:grid;gap:20px}.grid-2{grid-template-columns:repeat(2,1fr)}.grid-3{grid-template-columns:repeat(3,1fr)}.grid-4{grid-template-columns:repeat(4,1fr)}@media(max-width:900px){.grid-3,.grid-4{grid-template-columns:repeat(2,1fr)}}@media(max-width:600px){.grid-2,.grid-3,.grid-4{grid-template-columns:1fr}.navbar{padding:12px 16px}.navbar-nav{gap:12px}}.auth-container{position:fixed;inset:0;overflow:hidden;display:flex;align-items:center;justify-content:center;background:var(--bg-base);padding:70px 16px 16px}.auth-card{width:100%;max-width:400px;background:var(--bg-elevated);border-radius:var(--radius-xl);padding:32px 28px;border:1px solid var(--border)}.auth-title{text-align:center;font-size:1.5rem;margin-bottom:8px}.auth-subtitle{text-align:center;color:var(--text-secondary);margin-bottom:24px;font-size:.95rem}.auth-footer{text-align:center;margin-top:16px;color:var(--text-secondary);font-size:.9rem}.set-card{background:var(--bg-elevated);border-radius:var(--radius-lg);padding:20px;border:1px solid var(--border);transition:all var(--transition-base);display:flex;flex-direction:column;height:100%}.set-card:hover{border-color:var(--primary);transform:translateY(-2px);box-shadow:var(--shadow-md)}.set-card-title{font-size:1.1rem;margin-bottom:6px;font-weight:600}.set-card-desc{color:var(--text-muted);font-size:.85rem;margin-bottom:12px;display:-webkit-box;-webkit-line-clamp:2;line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;min-height:2.4em}.set-card-meta{color:var(--text-muted);font-size:.8rem;display:flex;align-items:center;gap:16px;margin-bottom:16px;margin-top:auto}.set-card-actions{display:flex;gap:8px;flex-wrap:wrap}.study-controls{display:flex;justify-content:center;gap:10px;margin-top:28px;flex-wrap:wrap}.study-btn{padding:14px 24px;border-radius:var(--radius-md);font-size:.9rem;font-weight:600;border:none;cursor:pointer;transition:all var(--transition-base);min-width:100px}.study-btn.again{background:var(--error);color:#fff}.study-btn.hard{background:var(--warning);color:#1a1a1a}.study-btn.good{background:var(--info);color:#fff}.study-btn.easy{background:var(--success);color:#fff}.study-btn:hover{transform:scale(1.03);filter:brightness(1.1)}.progress-bar{width:100%;height:6px;background:var(--bg-surface);border-radius:3px;overflow:hidden}.progress-fill{height:100%;background:var(--primary);border-radius:3px;transition:width var(--transition-base)}.quiz-option{display:block;width:100%;padding:16px 20px;background:var(--bg-surface);border:1px solid var(--border);border-radius:var(--radius-md);color:var(--text-primary);font-size:.95rem;text-align:left;cursor:pointer;transition:all var(--transition-base);margin-bottom:10px}.quiz-option:hover{border-color:var(--primary);background:var(--bg-hover)}.quiz-option.correct{border-color:var(--success);background:#22c55e1a}.quiz-option.incorrect{border-color:var(--error);background:#ef44441a}.quiz-option.selected{border-color:var(--primary);background:var(--primary-subtle)}.empty-state{text-align:center;padding:60px 20px;color:var(--text-secondary)}.empty-state-icon{width:64px;height:64px;margin:0 auto 20px;background:var(--bg-surface);border-radius:var(--radius-lg);display:flex;align-items:center;justify-content:center}.empty-state-icon svg{width:32px;height:32px;stroke:var(--text-muted)}.empty-state-title{font-size:1.25rem;margin-bottom:8px;color:var(--text-primary)}.alert{padding:14px 18px;border-radius:var(--radius-md);margin-bottom:20px;font-size:.9rem}.alert-error{background:#ef44441a;border:1px solid var(--error);color:var(--error)}.alert-success{background:#22c55e1a;border:1px solid var(--success);color:var(--success)}@keyframes fadeIn{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}.fade-in{animation:fadeIn .25s ease-out}.loading{display:flex;align-items:center;justify-content:center;padding:60px;min-height:300px}.spinner{width:36px;height:36px;border:3px solid var(--bg-surface);border-top-color:var(--primary);border-radius:50%;animation:spin .7s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.text-center{text-align:center}.text-muted{color:var(--text-muted)}.text-secondary{color:var(--text-secondary)}.mt-1{margin-top:8px}.mt-2{margin-top:16px}.mt-3{margin-top:24px}.mb-1{margin-bottom:8px}.mb-2{margin-bottom:16px}.mb-3{margin-bottom:24px}.flex{display:flex}.flex-center{display:flex;align-items:center;justify-content:center}.gap-1{gap:8px}.gap-2{gap:16px}.hero{text-align:center;padding:80px 20px;max-width:700px;margin:0 auto}.hero-title{font-size:2.75rem;font-weight:800;letter-spacing:-.03em;margin-bottom:16px;line-height:1.1}.hero-title span{background:linear-gradient(135deg,var(--primary) 0%,var(--accent) 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.hero-desc{font-size:1.1rem;color:var(--text-secondary);margin-bottom:32px;line-height:1.7}.hero-actions{display:flex;justify-content:center;gap:12px;flex-wrap:wrap}.feature-card{background:var(--bg-elevated);border:1px solid var(--border);border-radius:var(--radius-lg);padding:28px 24px;text-align:center;transition:all var(--transition-base)}.feature-card:hover{border-color:var(--border-hover);transform:translateY(-2px)}.feature-icon{width:48px;height:48px;margin:0 auto 16px;background:var(--primary-subtle);border-radius:var(--radius-md);display:flex;align-items:center;justify-content:center}.feature-icon 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20px;background:var(--bg-surface);display:flex;align-items:center;gap:10px;font-size:.85rem;flex-wrap:wrap}.ai-chat-term{color:var(--primary);font-weight:600}.ai-chat-sep{color:var(--text-muted)}.ai-chat-def{color:var(--text-secondary)}.ai-chat-messages{flex:1;overflow-y:auto;padding:16px;display:flex;flex-direction:column;gap:12px}.ai-chat-msg{max-width:90%;padding:12px 16px;border-radius:var(--radius-lg);font-size:.9rem;line-height:1.6}.ai-chat-msg.user{align-self:flex-end;background:var(--primary);color:#fff;border-bottom-right-radius:4px}.ai-chat-msg.assistant{align-self:flex-start;background:var(--bg-surface);color:var(--text-primary);border-bottom-left-radius:4px}.ai-chat-msg.assistant h1,.ai-chat-msg.assistant h2,.ai-chat-msg.assistant h3{font-size:1rem;margin:8px 0 4px}.ai-chat-msg.assistant p{margin:8px 0}.ai-chat-msg.assistant ul,.ai-chat-msg.assistant ol{margin:8px 0;padding-left:20px}.ai-chat-msg.assistant li{margin:4px 0}.ai-chat-msg.assistant strong{color:var(--primary-light)}.ai-chat-msg.assistant code{background:var(--bg-hover);padding:2px 6px;border-radius:4px;font-size:.85em}.ai-typing{display:flex;gap:4px;padding:8px 0}.ai-typing span{width:8px;height:8px;background:var(--text-muted);border-radius:50%;animation:typing 1.4s infinite}.ai-typing span:nth-child(2){animation-delay:.2s}.ai-typing span:nth-child(3){animation-delay:.4s}@keyframes typing{0%,60%,to{opacity:.3;transform:translateY(0)}30%{opacity:1;transform:translateY(-4px)}}.ai-quick-questions{display:flex;gap:8px;padding:12px 16px;overflow-x:auto;border-top:1px solid var(--border)}.ai-quick-btn{padding:6px 12px;background:var(--bg-surface);border:1px solid var(--border);border-radius:var(--radius-md);color:var(--text-secondary);font-size:.8rem;white-space:nowrap;cursor:pointer;transition:all var(--transition-fast)}.ai-quick-btn:hover{border-color:var(--primary);color:var(--primary)}.ai-chat-input-form{display:flex;gap:10px;padding:16px;border-top:1px solid var(--border)}.ai-chat-input{flex:1;padding:12px 16px;background:var(--bg-surface);border:1px solid var(--border);border-radius:var(--radius-md);color:var(--text-primary);font-size:.9rem}.ai-chat-input:focus{outline:none;border-color:var(--primary)}.ai-chat-input::placeholder{color:var(--text-muted)}.ai-chat-send{width:44px;height:44px;background:var(--primary);border:none;border-radius:var(--radius-md);color:#fff;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all var(--transition-fast)}.ai-chat-send:hover:not(:disabled){background:var(--primary-dark)}.ai-chat-send:disabled{opacity:.5;cursor:not-allowed}.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-bottom:32px}@media(max-width:700px){.stats-grid{grid-template-columns:repeat(2,1fr)}}.stat-card{background:var(--bg-elevated);border:1px solid var(--border);border-radius:var(--radius-lg);padding:24px 16px;text-align:center;transition:all var(--transition-base)}.stat-card:hover{border-color:var(--primary);transform:translateY(-2px)}.stat-icon{font-size:2rem;margin-bottom:8px}.stat-value{font-size:2rem;font-weight:700;color:var(--text-primary);line-height:1}.stat-label{font-size:.8rem;color:var(--text-muted);margin-top:6px}.profile-section{margin-bottom:32px}.section-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px}.section-header h2{font-size:1.25rem}.badge{background:var(--primary-subtle);color:var(--primary);padding:4px 12px;border-radius:20px;font-size:.8rem;font-weight:600}.achievements-grid{display:grid;gap:12px}.achievement-card{display:flex;align-items:center;gap:16px;background:var(--bg-elevated);border:1px solid var(--border);border-radius:var(--radius-md);padding:16px;transition:all var(--transition-base)}.achievement-card.unlocked{border-color:var(--success);background:#22c55e0d}.achievement-card.locked{opacity:.6}.achievement-icon{font-size:2rem;width:48px;text-align:center}.achievement-info{flex:1}.achievement-name{font-weight:600;color:var(--text-primary)}.achievement-desc{font-size:.85rem;color:var(--text-muted);margin-top:2px}.achievement-check{color:var(--success);font-size:1.25rem;font-weight:700}.achievement-xp{color:var(--primary);font-size:.85rem;font-weight:600}.achievement-card.exclusive{position:relative;background:transparent;padding:18px;overflow:hidden;z-index:0;border:none;box-shadow:0 0 25px #0f172a80}.achievement-card.exclusive:before{content:"";position:absolute;top:50%;left:50%;width:250%;height:250%;transform:translate(-50%,-50%);background:conic-gradient(transparent 0deg,transparent 280deg,#38bdf8 300deg,#94a3b8 340deg,#ffffff 360deg);animation:rotate-lightning 4s linear infinite;z-index:-2}.achievement-card.exclusive:after{content:"";position:absolute;inset:2px;background:linear-gradient(135deg,#1e293b,#0f172a);border-radius:calc(var(--radius-md) - 1px);z-index:-1;box-shadow:inset 0 0 40px #00000080}@keyframes rotate-lightning{0%{transform:translate(-50%,-50%) rotate(0)}to{transform:translate(-50%,-50%) rotate(360deg)}}.achievement-card.exclusive .achievement-check,.achievement-card.exclusive .achievement-name{color:#e2e8f0;text-shadow:0 0 15px rgba(56,189,248,.3);font-weight:700}.achievement-card.exclusive .achievement-desc{color:#94a3b8}.achievement-card.exclusive .achievement-icon{filter:drop-shadow(0 0 10px rgba(255,255,255,.2))}.badge-exclusive{background:linear-gradient(135deg,#fbbf24,#f59e0b);color:#1a1a1a;font-weight:700}.profile-actions{display:flex;gap:12px;justify-content:center;margin-top:32px}.leaderboard-list{display:flex;flex-direction:column;gap:12px}.leaderboard-item{display:flex;align-items:center;gap:16px;background:var(--bg-elevated);border:1px solid var(--border);border-radius:var(--radius-lg);padding:16px 20px;transition:all var(--transition-base)}.leaderboard-item:hover{border-color:var(--border-hover)}.leaderboard-item.gold{border-color:gold;background:linear-gradient(135deg,rgba(255,215,0,.1),transparent)}.leaderboard-item.silver{border-color:silver;background:linear-gradient(135deg,rgba(192,192,192,.1),transparent)}.leaderboard-item.bronze{border-color:#cd7f32;background:linear-gradient(135deg,rgba(205,127,50,.1),transparent)}.streak-fire{display:inline-block;position:relative;filter:drop-shadow(0 0 2px rgba(255,215,0,.8)) drop-shadow(0 -2px 4px rgba(255,69,0,.6)) drop-shadow(0 -4px 8px rgba(255,0,0,.4));animation:fire-3d 2s ease-in-out infinite;transform-origin:center bottom}@keyframes fire-3d{0%{transform:scale(1) rotate(0) translateY(0);filter:drop-shadow(0 0 2px rgba(255,215,0,.8)) drop-shadow(0 -2px 4px rgba(255,69,0,.6)) drop-shadow(0 -4px 8px rgba(255,0,0,.4))}25%{transform:scale(1.1) rotate(-2deg) translateY(-1px);filter:drop-shadow(0 0 4px rgba(255,215,0,.9)) drop-shadow(-2px -5px 6px rgba(255,69,0,.7)) drop-shadow(-1px -8px 12px rgba(255,0,0,.5))}50%{transform:scale(1.05) rotate(2deg) translateY(-2px);filter:drop-shadow(0 0 6px rgba(255,215,0,1)) drop-shadow(2px -6px 8px rgba(255,69,0,.8)) drop-shadow(1px -10px 15px rgba(255,0,0,.6))}75%{transform:scale(1.15) rotate(-1deg) translateY(-1px);filter:drop-shadow(0 0 4px rgba(255,215,0,.9)) drop-shadow(-1px -5px 6px rgba(255,69,0,.7)) drop-shadow(0 -8px 12px rgba(255,0,0,.5))}to{transform:scale(1) rotate(0) translateY(0);filter:drop-shadow(0 0 2px rgba(255,215,0,.8)) drop-shadow(0 -2px 4px rgba(255,69,0,.6)) drop-shadow(0 -4px 8px rgba(255,0,0,.4))}}.lb-rank{font-size:1.5rem;width:40px;text-align:center}.lb-user{flex:1}.lb-username{font-weight:600;color:var(--text-primary);font-size:1.1rem}.lb-stats{display:flex;gap:16px;margin-top:4px;font-size:.8rem;color:var(--text-muted)}.lb-xp{text-align:right}.lb-xp-value{font-size:1.5rem;font-weight:700;color:var(--primary);display:block}.lb-xp-label{font-size:.75rem;color:var(--text-muted);text-transform:uppercase}.navbar-user-link{display:flex;align-items:center}.navbar-user-link:hover .navbar-user{color:var(--primary-light)}.leaderboard-item{text-decoration:none;color:inherit}.lb-badge{margin-left:8px;font-size:1rem}.lb-streak{text-align:right}.lb-streak-value{font-size:1.5rem;font-weight:700;display:block}.lb-streak-label{font-size:.75rem;color:var(--text-muted)}@media(max-width:768px){html{font-size:14px}.container{padding:0 16px}.navbar{padding:12px 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