@import "https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Outfit:wght@300;400;500;600;700;800;900&display=swap";
:root{--font-sans:"Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;--font-display:"Outfit", sans-serif;--bg-primary:#eff6ff;--bg-secondary:#fff;--bg-tertiary:#f9fafb;--text-primary:#111827;--text-secondary:#374151;--text-muted:#6b7280;--brand-primary:#1e3a5f;--brand-primary-light:#2b4e7e;--brand-secondary:#2563eb;--brand-secondary-light:#60a5fa;--accent-gold:#f59e0b;--accent-success:#10b981;--accent-danger:#ef4444;--accent-premium:#8b5cf6;--border-light:#e5e7eb;--border-glow:#2563eb26;--glass-bg:#ffffffbf;--glass-border:#ffffff80;--glass-shadow:0 8px 32px 0 #1e3a8a0a;--card-radius:16px;--transition-smooth:all .3s cubic-bezier(.4, 0, .2, 1)}[data-theme=dark]{--bg-primary:#0b0f19;--bg-secondary:#111827;--bg-tertiary:#1f2937;--text-primary:#f9fafb;--text-secondary:#cbd5e1;--text-muted:#6b7280;--brand-primary:#1e3a5f;--brand-primary-light:#2b4e7e;--brand-secondary:#3b82f6;--brand-secondary-light:#60a5fa;--accent-success:#10b981;--border-light:#1f2937;--border-glow:#3b82f640;--glass-bg:#111827bf;--glass-border:#1f293780;--glass-shadow:0 8px 32px 0 #0000005e}*{box-sizing:border-box;margin:0;padding:0}body{font-family:var(--font-sans);background-color:var(--bg-primary);color:var(--text-primary);min-height:100vh;transition:var(--transition-smooth);line-height:1.5;overflow-x:hidden}h1,h2,h3,h4,h5,h6{font-family:var(--font-display);color:var(--text-primary);font-weight:700}a{color:inherit;text-decoration:none}::-webkit-scrollbar{width:6px;height:6px}::-webkit-scrollbar-track{background:var(--bg-primary)}::-webkit-scrollbar-thumb{background:var(--text-muted);border-radius:3px}::-webkit-scrollbar-thumb:hover{background:var(--brand-primary)}.glass-panel{background:var(--glass-bg);-webkit-backdrop-filter:blur(16px);border:1px solid var(--glass-border);box-shadow:var(--glass-shadow);border-radius:var(--card-radius);transition:var(--transition-smooth)}.glass-panel:hover{border-color:var(--border-glow);box-shadow:0 8px 24px #0f766e14}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}@keyframes slideInLeft{0%{opacity:0;transform:translate(-20px)}to{opacity:1;transform:translate(0)}}@keyframes pulseGlow{0%{box-shadow:0 0 #14b8a666}70%{box-shadow:0 0 0 8px #14b8a600}to{box-shadow:0 0 #14b8a600}}.auth-container{background:linear-gradient(135deg, var(--bg-primary) 0%, #0d2c29 100%);justify-content:center;align-items:center;min-height:100vh;padding:24px;animation:.6s ease-out fadeIn;display:flex}[data-theme=dark] .auth-container{background:linear-gradient(135deg,#07090e 0%,#0c1817 100%)}.auth-card{width:100%;max-width:480px;padding:40px}.auth-header{text-align:center;margin-bottom:32px}.auth-title{background:linear-gradient(to right, var(--brand-primary), var(--brand-secondary));-webkit-text-fill-color:transparent;-webkit-background-clip:text;margin-bottom:8px;font-size:2.2rem}.auth-subtitle{color:var(--text-secondary);font-size:.95rem}.form-group{margin-bottom:20px}.form-label{color:var(--text-secondary);margin-bottom:6px;font-size:.9rem;font-weight:500;display:block}.form-input{border:1px solid var(--border-light);background-color:var(--bg-secondary);width:100%;color:var(--text-primary);font-family:var(--font-sans);transition:var(--transition-smooth);border-radius:8px;padding:12px 16px;font-size:.95rem}.form-input:focus{border-color:var(--text-primary);outline:none;box-shadow:0 0 0 3px #2563eb26}.form-row{gap:16px;display:flex}.form-row .form-group{flex:1}.btn{font-weight:600;font-family:var(--font-display);cursor:pointer;transition:var(--transition-smooth);border:none;border-radius:8px;justify-content:center;align-items:center;gap:8px;padding:12px 24px;font-size:.95rem;display:inline-flex}.btn-primary{background:linear-gradient(135deg, var(--brand-secondary), var(--brand-secondary-light));color:#fff}.btn-primary:hover{transform:translateY(-2px);box-shadow:0 4px 12px #2563eb59}.btn-secondary{background-color:var(--bg-tertiary);color:var(--text-primary);border:1px solid var(--border-light)}.btn-secondary:hover{background-color:var(--border-light)}.btn-full{width:100%}.auth-footer{text-align:center;color:var(--text-secondary);margin-top:24px;font-size:.9rem}.auth-link{color:var(--brand-primary);cursor:pointer;font-weight:600}.auth-link:hover{text-decoration:underline}.app-layout{min-height:100vh;display:flex}.main-content{background-color:var(--bg-primary);height:100vh;transition:var(--transition-smooth);flex:1;padding:32px;overflow-y:auto}.sidebar{background-color:var(--brand-primary);width:280px;height:100vh;transition:var(--transition-smooth);color:#fff;border-right:1px solid #ffffff26;flex-direction:column;flex-shrink:0;padding:24px;display:flex}.sidebar-logo{font-family:var(--font-display);color:#fff;align-items:center;gap:12px;margin-bottom:32px;font-size:1.8rem;font-weight:900;display:flex}.sidebar-nav{flex-direction:column;flex:1;gap:8px;display:flex}.sidebar-item{cursor:pointer;color:#ffffffb3;transition:var(--transition-smooth);border-radius:8px;align-items:center;gap:16px;padding:12px 16px;font-weight:500;display:flex}.sidebar-item:hover{color:#fff;background-color:#ffffff1a}.sidebar-item.active{background-color:var(--brand-secondary);color:#fff;box-shadow:0 4px 12px #2563eb59}.sidebar-footer{border-top:1px solid #ffffff1a;margin-top:auto;padding-top:16px}.dashboard-grid{grid-template-columns:repeat(auto-fit,minmax(320px,1fr));gap:24px;margin-top:24px;display:grid}.stat-card{align-items:center;gap:20px;padding:24px;display:flex}.stat-icon-wrapper{background:var(--border-glow);width:56px;height:56px;color:var(--brand-primary);border-radius:12px;justify-content:center;align-items:center;display:flex}.stat-info h3{font-size:1.8rem;line-height:1.2}.stat-info p{color:var(--text-secondary);font-size:.9rem}.section-header{justify-content:space-between;align-items:center;margin-bottom:24px;display:flex}.section-title-wrap h1{margin-bottom:4px;font-size:2.2rem}.section-title-wrap p{color:var(--text-secondary)}.study-container{flex-direction:column;gap:24px;display:flex}.study-modes{border-bottom:1px solid var(--border-light);gap:12px;padding-bottom:12px;display:flex}.study-mode-btn{cursor:pointer;transition:var(--transition-smooth);color:var(--text-secondary);background:0 0;border:none;border-radius:8px;padding:10px 20px;font-weight:600}.study-mode-btn.active{background-color:var(--border-glow);color:var(--brand-secondary)}.study-main-grid{grid-template-columns:280px 1fr;align-items:stretch;gap:24px;display:grid}.outline-panel{height:100%;max-height:100%;padding:16px;overflow-y:auto}.outline-chapter{margin-bottom:16px}.outline-chapter-title{color:var(--brand-primary);margin-bottom:8px;font-size:.95rem;font-weight:700}.outline-topic-list{flex-direction:column;gap:6px;display:flex}.outline-topic-item{cursor:pointer;transition:var(--transition-smooth);border:1px solid #0000;border-radius:6px;padding:10px 12px;font-size:.85rem}.outline-topic-item:hover{background-color:var(--bg-tertiary)}.outline-topic-item.active{background-color:var(--bg-secondary);border-color:var(--brand-secondary);color:var(--brand-secondary);font-weight:600}.video-view{flex-direction:column;gap:20px;display:flex}.video-player-container{aspect-ratio:16/9;background-color:#000;border-radius:12px;width:100%;position:relative;overflow:hidden}.video-engagement-bar{border-bottom:1px solid var(--border-light);justify-content:space-between;align-items:center;padding:12px 0;display:flex}.engagement-actions{gap:16px;display:flex}.action-btn{cursor:pointer;color:var(--text-secondary);transition:var(--transition-smooth);background:0 0;border:none;align-items:center;gap:6px;font-size:.9rem;font-weight:500;display:inline-flex}.action-btn:hover,.action-btn.active{color:var(--brand-primary)}.comments-container{flex-direction:column;gap:16px;margin-top:16px;display:flex}.comment-input-wrap{gap:12px;display:flex}.comment-input{border:1px solid var(--border-light);background-color:var(--bg-secondary);color:var(--text-primary);border-radius:8px;flex:1;padding:12px;font-size:.9rem}.comment-list{flex-direction:column;gap:12px;max-height:400px;padding-right:8px;display:flex;overflow-y:auto}.comment-item{background-color:var(--bg-tertiary);border-radius:8px;padding:12px}.comment-meta{color:var(--text-secondary);justify-content:space-between;margin-bottom:4px;font-size:.8rem;display:flex}.comment-author{font-weight:600}.comment-text{font-size:.9rem}.textbook-view{padding:24px}.textbook-controls{border-bottom:1px solid var(--border-light);flex-wrap:wrap;align-items:center;gap:16px;margin-bottom:20px;padding-bottom:12px;display:flex}.control-group{align-items:center;gap:8px;font-size:.85rem;display:flex}.textbook-content{max-width:800px;margin:0 auto;font-size:1.05rem;line-height:1.7}.exam-view{max-width:720px;margin:0 auto;padding:24px}.question-card{margin-bottom:20px;padding:24px}.question-text{margin-bottom:20px;font-size:1.2rem;font-weight:600}.option-list{flex-direction:column;gap:12px;margin-bottom:24px;display:flex}.option-item{border:1px solid var(--border-light);cursor:pointer;transition:var(--transition-smooth);background-color:var(--bg-secondary);border-radius:8px;align-items:center;padding:16px;display:flex}.option-item:hover{border-color:var(--brand-primary);background-color:var(--bg-tertiary)}.option-item.selected{border-color:var(--brand-primary);background-color:var(--border-glow)}.option-item.correct{border-color:var(--accent-success);background-color:#10b9811a}.option-item.wrong{border-color:var(--accent-danger);background-color:#ef44441a}.explanation-panel{background-color:var(--bg-tertiary);border-left:4px solid var(--brand-primary);border-radius:0 8px 8px 0;margin-bottom:20px;padding:16px;animation:.4s ease-out fadeIn}.leaderboard-list{flex-direction:column;gap:12px;display:flex}.leaderboard-row{justify-content:space-between;align-items:center;padding:16px 24px;display:flex}.leaderboard-profile{align-items:center;gap:16px;display:flex}.leaderboard-avatar{background-color:var(--brand-primary);color:#fff;border-radius:50%;justify-content:center;align-items:center;width:44px;height:44px;font-weight:700;display:flex}.leaderboard-rank{width:32px;font-size:1.2rem;font-weight:800}.chat-container{grid-template-columns:260px 1fr;gap:20px;height:calc(100vh - 180px);display:grid}.chat-threads-list{flex-direction:column;gap:8px;display:flex}.chat-thread-item{cursor:pointer;transition:var(--transition-smooth);border-radius:8px;padding:14px 16px}.chat-thread-item:hover{background-color:var(--bg-tertiary)}.chat-thread-item.active{background-color:var(--brand-primary);color:#fff}.chat-window{flex-direction:column;height:100%;display:flex}.chat-messages{flex-direction:column;flex:1;gap:16px;padding:16px;display:flex;overflow-y:auto}.message-bubble{border-radius:12px;max-width:70%;padding:12px 16px;font-size:.95rem}.message-bubble.incoming{background-color:var(--bg-tertiary);align-self:flex-start}.message-bubble.outgoing{background-color:var(--brand-primary);color:#fff;align-self:flex-end}.chat-input-area{border-top:1px solid var(--border-light);gap:12px;padding:16px 0;display:flex}.chat-suggestions{flex-wrap:wrap;gap:8px;margin-bottom:12px;display:flex}.suggestion-chip{background-color:var(--bg-tertiary);cursor:pointer;transition:var(--transition-smooth);border-radius:16px;padding:6px 12px;font-size:.8rem}.suggestion-chip:hover{background-color:var(--border-glow);color:var(--brand-primary)}.calendar-grid{grid-template-columns:repeat(7,1fr);gap:8px;margin-top:16px;display:grid}.calendar-day{aspect-ratio:1;background-color:var(--bg-tertiary);transition:var(--transition-smooth);border-radius:8px;justify-content:center;align-items:center;font-size:.8rem;font-weight:600;display:flex}.calendar-day.active{background-color:var(--brand-primary);color:#fff;animation:2s infinite pulseGlow}.milestones-timeline{flex-direction:column;gap:24px;padding-left:20px;display:flex;position:relative}.milestones-timeline:before{content:"";background-color:var(--border-light);width:2px;position:absolute;top:0;bottom:0;left:6px}.milestone-node{align-items:start;gap:20px;display:flex;position:relative}.milestone-dot{background-color:var(--text-muted);border:3px solid var(--bg-primary);z-index:2;border-radius:50%;width:14px;height:14px;position:absolute;top:6px;left:-20px}.milestone-dot.unlocked{background-color:var(--accent-gold)}.milestone-card{flex:1;padding:16px}@media (max-width:768px){.app-layout{flex-direction:column}.sidebar{border-bottom:1px solid #ffffff26;border-right:none;width:100%;height:auto;padding:12px 16px}.sidebar-logo{margin-bottom:12px}.sidebar-nav{flex-direction:row;padding-bottom:6px;overflow-x:auto}.sidebar-item{white-space:nowrap;padding:8px 12px;font-size:.85rem}.sidebar-footer{display:none}.main-content{height:auto;padding:16px}.study-main-grid{grid-template-columns:1fr}.chat-container{grid-template-columns:1fr;height:calc(100vh - 240px)}}.study-main-grid:fullscreen{background-color:var(--bg-primary)!important;box-sizing:border-box!important;flex-direction:column!important;width:100vw!important;height:100vh!important;padding:24px!important;display:flex!important;overflow:hidden!important}.tts-word{border-radius:4px;padding:1px 3px;transition:background-color .1s,color .1s;display:inline}.tts-word-active{color:#0f172a!important;background-color:#facc15!important;font-weight:700!important;box-shadow:0 0 10px #facc15e6!important}.tts-active-segment{border-radius:4px;transition:all .3s;border-left:4px solid var(--brand-secondary)!important;background-color:#2563eb0d!important;padding-left:12px!important}