:root{color-scheme:dark;font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;line-height:1.5;--bg-primary: #0a0a1a;--bg-secondary: #101028;--bg-card: #16163a;--bg-card-hover: #1e1e4a;--bg-input: #12122e;--accent: #6366f1;--accent-hover: #818cf8;--accent-glow: rgba(99, 102, 241, .25);--violet: #8b5cf6;--cyan: #06b6d4;--green: #10b981;--amber: #f59e0b;--rose: #f43f5e;--pink: #ec4899;--teal: #14b8a6;--text-primary: #f1f5f9;--text-secondary: #94a3b8;--text-muted: #64748b;--border: rgba(255, 255, 255, .08);--border-hover: rgba(255, 255, 255, .15);--radius: 14px;--radius-sm: 10px;--radius-xs: 6px;--shadow: 0 4px 24px rgba(0, 0, 0, .4);--transition: .2s ease}*{box-sizing:border-box;margin:0;padding:0}html,body,#root{min-height:100vh;background:var(--bg-primary);color:var(--text-primary)}.app{display:flex;min-height:100vh}.sidebar{width:260px;min-height:100vh;background:var(--bg-secondary);border-right:1px solid var(--border);padding:24px 16px;display:flex;flex-direction:column;gap:8px;position:fixed;top:0;left:0;z-index:100}.sidebar-logo{display:flex;align-items:center;gap:10px;padding:8px 12px;margin-bottom:16px}.sidebar-logo-icon{width:36px;height:36px;background:linear-gradient(135deg,var(--accent),var(--violet));border-radius:10px;display:flex;align-items:center;justify-content:center;font-size:18px;font-weight:700;color:#fff}.sidebar-logo-text{font-size:20px;font-weight:700;letter-spacing:-.03em;background:linear-gradient(135deg,var(--accent-hover),var(--violet));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.sidebar-section{font-size:11px;font-weight:600;text-transform:uppercase;letter-spacing:.08em;color:var(--text-muted);padding:16px 12px 6px}.nav-item{display:flex;align-items:center;gap:12px;padding:10px 12px;border-radius:var(--radius-sm);cursor:pointer;transition:all var(--transition);font-size:14px;font-weight:500;color:var(--text-secondary);border:1px solid transparent;background:none;width:100%;text-align:left}.nav-item:hover{background:var(--bg-card);color:var(--text-primary)}.nav-item.active{background:var(--accent-glow);color:var(--accent-hover);border-color:#6366f133}.nav-icon{font-size:18px;width:24px;text-align:center;flex-shrink:0}.main-content{flex:1;margin-left:260px;padding:32px;min-height:100vh;overflow-y:auto}.page-header{margin-bottom:28px}.page-header h1{font-size:28px;font-weight:700;letter-spacing:-.03em;margin-bottom:6px}.page-header p{color:var(--text-secondary);font-size:15px}.card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:24px;transition:all var(--transition)}.card:hover{border-color:var(--border-hover)}.card-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:18px}.card-title{font-size:16px;font-weight:600;letter-spacing:-.01em}.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}.stat-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:20px;display:flex;flex-direction:column;gap:8px}.stat-icon{font-size:24px;width:44px;height:44px;display:flex;align-items:center;justify-content:center;border-radius:12px;background:#6366f11a}.stat-value{font-size:28px;font-weight:700;letter-spacing:-.03em}.stat-label{font-size:13px;color:var(--text-secondary)}.btn{display:inline-flex;align-items:center;gap:8px;padding:10px 18px;border-radius:var(--radius-sm);font-size:14px;font-weight:500;cursor:pointer;transition:all var(--transition);border:1px solid var(--border);background:var(--bg-card);color:var(--text-primary)}.btn:hover{background:var(--bg-card-hover);border-color:var(--border-hover)}.btn-primary{background:var(--accent);border-color:var(--accent);color:#fff}.btn-primary:hover{background:var(--accent-hover);border-color:var(--accent-hover)}.btn-sm{padding:6px 12px;font-size:13px;border-radius:var(--radius-xs)}.btn-danger{background:#f43f5e1a;border-color:#f43f5e33;color:var(--rose)}.btn-danger:hover{background:#f43f5e33}.btn-icon{padding:8px;border:none;background:none;color:var(--text-muted);cursor:pointer;border-radius:var(--radius-xs);transition:all var(--transition);font-size:16px}.btn-icon:hover{background:var(--bg-card);color:var(--text-primary)}.input-group{display:flex;flex-direction:column;gap:6px}.input-group label{font-size:13px;font-weight:500;color:var(--text-secondary)}input,textarea,select{padding:10px 14px;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--bg-input);color:var(--text-primary);font-size:14px;font-family:inherit;transition:border-color var(--transition);outline:none}input:focus,textarea:focus,select:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-glow)}textarea{resize:vertical;min-height:100px}select{cursor:pointer}.badge{display:inline-flex;align-items:center;padding:3px 10px;border-radius:20px;font-size:12px;font-weight:600}.badge-accent{background:#6366f126;color:var(--accent-hover)}.badge-green{background:#10b98126;color:var(--green)}.badge-amber{background:#f59e0b26;color:var(--amber)}.badge-rose{background:#f43f5e26;color:var(--rose)}.badge-cyan{background:#06b6d426;color:var(--cyan)}.badge-violet{background:#8b5cf626;color:var(--violet)}.tabs{display:flex;gap:4px;background:var(--bg-secondary);padding:4px;border-radius:var(--radius-sm);margin-bottom:20px;border:1px solid var(--border)}.tab{padding:8px 16px;border-radius:var(--radius-xs);font-size:13px;font-weight:500;cursor:pointer;transition:all var(--transition);color:var(--text-secondary);background:none;border:none}.tab:hover{color:var(--text-primary);background:var(--bg-card)}.tab.active{background:var(--accent);color:#fff}.list-item{display:flex;align-items:center;gap:14px;padding:14px 16px;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--bg-secondary);transition:all var(--transition);margin-bottom:8px}.list-item:hover{border-color:var(--border-hover);background:var(--bg-card)}.checkbox{width:20px;height:20px;border-radius:6px;border:2px solid var(--border-hover);cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all var(--transition);flex-shrink:0;background:none;color:transparent;font-size:12px}.checkbox.checked{background:var(--green);border-color:var(--green);color:#fff}.calendar-grid{display:grid;grid-template-columns:60px repeat(7,1fr);gap:1px;background:var(--border);border-radius:var(--radius);overflow:hidden}.calendar-header-cell{background:var(--bg-secondary);padding:12px 8px;text-align:center;font-size:13px;font-weight:600;color:var(--text-secondary)}.calendar-header-cell.today{color:var(--accent)}.calendar-time{background:var(--bg-secondary);padding:8px;font-size:12px;color:var(--text-muted);text-align:right;height:60px;display:flex;align-items:flex-start;justify-content:flex-end}.calendar-cell{background:var(--bg-primary);min-height:60px;position:relative}.calendar-event{position:absolute;left:2px;right:2px;padding:4px 6px;border-radius:4px;font-size:11px;font-weight:500;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;cursor:pointer}.timer-container{display:flex;flex-direction:column;align-items:center;gap:32px}.timer-ring{position:relative;width:280px;height:280px}.timer-ring svg{transform:rotate(-90deg)}.timer-ring-bg{fill:none;stroke:var(--border);stroke-width:8}.timer-ring-progress{fill:none;stroke:var(--accent);stroke-width:8;stroke-linecap:round;transition:stroke-dashoffset 1s linear}.timer-display{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);text-align:center}.timer-time{font-size:56px;font-weight:700;letter-spacing:-.04em;font-variant-numeric:tabular-nums}.timer-label{font-size:14px;color:var(--text-secondary);margin-top:4px}.timer-controls{display:flex;gap:12px}.sound-selector{display:flex;gap:10px;flex-wrap:wrap;justify-content:center}.sound-btn{padding:12px 20px;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--bg-card);color:var(--text-secondary);cursor:pointer;transition:all var(--transition);font-size:13px;font-weight:500;display:flex;flex-direction:column;align-items:center;gap:6px;min-width:90px}.sound-btn:hover{border-color:var(--border-hover);color:var(--text-primary)}.sound-btn.active{border-color:var(--accent);background:var(--accent-glow);color:var(--accent-hover)}.sound-icon{font-size:24px}.flashcard{width:100%;max-width:480px;height:300px;perspective:1200px;cursor:pointer;margin:0 auto}.flashcard-inner{width:100%;height:100%;position:relative;transform-style:preserve-3d;transition:transform .5s ease}.flashcard.flipped .flashcard-inner{transform:rotateY(180deg)}.flashcard-face{position:absolute;width:100%;height:100%;backface-visibility:hidden;border-radius:var(--radius);border:1px solid var(--border);display:flex;flex-direction:column;align-items:center;justify-content:center;padding:32px;text-align:center;font-size:20px;line-height:1.6}.flashcard-front{background:linear-gradient(135deg,var(--bg-card),var(--bg-secondary))}.flashcard-back{background:linear-gradient(135deg,rgba(99,102,241,.1),var(--bg-card));transform:rotateY(180deg)}.flashcard-subject{position:absolute;top:16px;left:16px;font-size:12px}.rating-buttons{display:flex;gap:8px;justify-content:center;margin-top:24px;flex-wrap:wrap}.rating-btn{padding:8px 18px;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--bg-card);color:var(--text-primary);cursor:pointer;transition:all var(--transition);font-size:13px;font-weight:500}.rating-btn:hover{border-color:var(--accent)}.rating-btn.again{border-color:var(--rose);color:var(--rose)}.rating-btn.hard{border-color:var(--amber);color:var(--amber)}.rating-btn.good{border-color:var(--green);color:var(--green)}.rating-btn.easy{border-color:var(--cyan);color:var(--cyan)}.bar-chart{display:flex;align-items:flex-end;gap:12px;height:200px;padding-top:20px}.bar-group{flex:1;display:flex;flex-direction:column;align-items:center;gap:8px;height:100%}.bar{width:100%;max-width:48px;border-radius:6px 6px 0 0;transition:height .5s ease;min-height:4px}.bar-label{font-size:11px;color:var(--text-muted);text-align:center}.bar-value{font-size:12px;font-weight:600;color:var(--text-secondary)}.search-box{position:relative}.search-box input{width:100%;padding-left:38px}.search-icon{position:absolute;left:12px;top:50%;transform:translateY(-50%);color:var(--text-muted);font-size:14px;pointer-events:none}.modal-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#0009;display:flex;align-items:center;justify-content:center;z-index:1000;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}.modal{background:var(--bg-secondary);border:1px solid var(--border);border-radius:var(--radius);padding:28px;width:90%;max-width:480px;max-height:90vh;overflow-y:auto}.modal h2{font-size:20px;font-weight:600;margin-bottom:20px}.modal-actions{display:flex;gap:10px;justify-content:flex-end;margin-top:24px}.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}.form-full{grid-column:1 / -1}.notebook-layout{display:grid;grid-template-columns:280px 1fr;gap:20px;height:calc(100vh - 140px)}.notebook-sidebar{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:16px;overflow-y:auto;display:flex;flex-direction:column;gap:12px}.notebook-main{display:flex;flex-direction:column;gap:16px}.note-item{padding:12px;border-radius:var(--radius-sm);border:1px solid var(--border);cursor:pointer;transition:all var(--transition)}.note-item:hover{background:var(--bg-card-hover)}.note-item.active{background:var(--accent-glow);border-color:#6366f14d}.note-item-title{font-size:14px;font-weight:600;margin-bottom:4px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.note-item-preview{font-size:12px;color:var(--text-muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.note-item-meta{font-size:11px;color:var(--text-muted);margin-top:6px;display:flex;gap:8px;align-items:center}.deck-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:16px}.deck-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:24px;cursor:pointer;transition:all var(--transition);text-align:center}.deck-card:hover{border-color:var(--accent);transform:translateY(-2px);box-shadow:var(--shadow)}.deck-icon{font-size:40px;margin-bottom:12px}.deck-name{font-size:16px;font-weight:600;margin-bottom:4px}.deck-count{font-size:13px;color:var(--text-muted)}.deck-due{margin-top:8px;font-size:12px;color:var(--amber)}.quiz-question{font-size:20px;font-weight:600;margin-bottom:24px;line-height:1.4}.quiz-options{display:flex;flex-direction:column;gap:10px}.quiz-option{padding:16px 20px;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--bg-card);cursor:pointer;transition:all var(--transition);font-size:15px;text-align:left;color:var(--text-primary);width:100%}.quiz-option:hover{border-color:var(--accent);background:var(--bg-card-hover)}.quiz-option.correct{border-color:var(--green);background:#10b9811a;color:var(--green)}.quiz-option.wrong{border-color:var(--rose);background:#f43f5e1a;color:var(--rose)}.empty-state{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:48px 24px;text-align:center;color:var(--text-muted)}.empty-icon{font-size:48px;margin-bottom:16px;opacity:.5}.empty-title{font-size:18px;font-weight:600;color:var(--text-secondary);margin-bottom:8px}.empty-text{font-size:14px;max-width:320px;margin-bottom:20px}.flex{display:flex}.flex-col{flex-direction:column}.items-center{align-items:center}.justify-between{justify-content:space-between}.gap-2{gap:8px}.gap-3{gap:12px}.gap-4{gap:16px}.gap-6{gap:24px}.flex-1{flex:1}.flex-wrap{flex-wrap:wrap}.w-full{width:100%}.mt-2{margin-top:8px}.mt-4{margin-top:16px}.mt-6{margin-top:24px}.mb-2{margin-bottom:8px}.mb-4{margin-bottom:16px}.text-sm{font-size:13px}.text-xs{font-size:12px}.text-center{text-align:center}.font-medium{font-weight:500}.font-semibold{font-weight:600}.text-muted{color:var(--text-muted)}.text-secondary{color:var(--text-secondary)}.truncate{white-space:nowrap;overflow:hidden;text-overflow:ellipsis}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:#ffffff1a;border-radius:3px}::-webkit-scrollbar-thumb:hover{background:#fff3}.tag{display:inline-flex;align-items:center;gap:4px;padding:2px 8px;border-radius:4px;font-size:11px;background:#6366f11a;color:var(--accent-hover);font-weight:500}.progress-bar{height:6px;background:var(--border);border-radius:3px;overflow:hidden}.progress-fill{height:100%;border-radius:3px;background:var(--accent);transition:width .5s ease}.tool-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:24px}.tool-result{background:var(--bg-primary);border:1px solid var(--border);border-radius:var(--radius-sm);padding:16px;margin-top:16px;font-size:14px;line-height:1.7;white-space:pre-wrap}@keyframes fadeIn{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}.fade-in{animation:fadeIn .3s ease}@media(max-width:1024px){.grid-4{grid-template-columns:repeat(2,1fr)}.notebook-layout{grid-template-columns:1fr;height:auto}.notebook-sidebar{max-height:300px}}@media(max-width:768px){.sidebar{display:none}.main-content{margin-left:0;padding:20px}.grid-3,.grid-2,.form-grid{grid-template-columns:1fr}.calendar-grid{display:none}}