:root{--bg-color:#f8fafc;--panel-bg:#fff;--accent-color:#3b82f6;--text-primary:#0f172a;--text-secondary:#64748b;--success:#10b981;--danger:#ef4444;--star-color:#fbbf24;--border-light:#0000000d;--shadow-soft:0 20px 50px -10px #0000001a;--font-family:"Inter", system-ui, -apple-system, sans-serif;--sidebar-width:240px}*{box-sizing:border-box;margin:0;padding:0}html{font-size:14px}body{background-color:var(--bg-color);color:var(--text-primary);font-family:var(--font-family);min-height:100vh;overflow-x:hidden}.app-layout{background:#e2e8f0;min-height:100vh;padding:2rem;display:flex}.main-container{background:var(--panel-bg);border-radius:3rem;flex:1;min-height:calc(100vh - 4rem);display:flex;position:relative;overflow:hidden;box-shadow:0 40px 100px -20px #00000026}.sidebar{width:var(--sidebar-width);border-right:1px solid var(--border-light);background:#fff;flex-direction:column;gap:2.5rem;padding:3rem 2rem;display:flex}.sidebar-logo{color:#000;letter-spacing:-1px;font-size:1.75rem;font-weight:900}.sidebar-item{cursor:pointer;color:var(--text-secondary);border-radius:1.25rem;align-items:center;gap:1rem;padding:.8rem 1.25rem;font-weight:600;transition:all .3s cubic-bezier(.4,0,.2,1);display:flex}.sidebar-item:hover{color:var(--text-primary);background:#f1f5f9}.sidebar-item.active{color:#fff;background:#000}.folder-grid{scroll-behavior:smooth;scrollbar-width:none;gap:2.5rem;padding:2rem 0;display:flex;overflow-x:auto}.folder-card{color:#fff;cursor:pointer;border-radius:2rem;flex-direction:column;justify-content:flex-end;min-width:240px;height:290px;margin-top:2.5rem;padding:1.75rem;transition:all .4s cubic-bezier(.175,.885,.32,1.275);display:flex;position:relative}.pop-out-icon{z-index:10;filter:drop-shadow(0 15px 30px #00000040);justify-content:center;align-items:center;width:110px;height:110px;transition:transform .4s;display:flex;position:absolute;top:-2.5rem;left:50%;transform:translate(-50%)}.folder-card:hover{transform:translateY(-10px)}.folder-card:hover .pop-out-icon{transform:translate(-50%)translateY(-10px)scale(1.1)}.folder-dsa{background:linear-gradient(#ffbd05,#ff8c00);box-shadow:0 20px 40px #ff8c004d}.folder-wap{background:linear-gradient(#00d2ff,#3a7bd5);box-shadow:0 20px 40px #3a7bd54d}.folder-maths{background:linear-gradient(#ff5f6d,#ffc371);box-shadow:0 20px 40px #ff5f6d4d}.folder-foai{background:linear-gradient(#8e2de2,#4a00e0);box-shadow:0 20px 40px #4a00e04d}.folder-name{margin-bottom:.5rem;font-size:2.25rem;font-weight:800;line-height:1}.folder-subtitle{opacity:.8;text-transform:uppercase;letter-spacing:1px;font-size:.9rem;font-weight:600}.main-content{flex:1;padding:3rem 4rem;overflow-y:auto}.header-top{justify-content:space-between;align-items:center;margin-bottom:4rem;padding:.5rem 0;display:flex}.search-bar-modern{background:#f1f5f9;border-radius:999px;align-items:center;gap:.75rem;width:250px;padding:.75rem 1.25rem;transition:all .3s;display:flex}.search-input{width:100%;color:var(--text-primary);background:0 0;border:none;outline:none;font-size:.85rem;font-weight:600}textarea.search-input{background:#fff;border:1px solid #e2e8f0;padding:1rem;font-family:JetBrains Mono,Fira Code,monospace;font-size:.8rem;line-height:1.5;transition:border-color .2s}textarea.search-input:focus{border-color:var(--accent-color)}.question-grid{grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:2.5rem;display:grid}.card{background:#fff;border:1px solid #f1f5f9;border-radius:2rem;padding:2rem;transition:all .3s;box-shadow:0 10px 30px #00000008}.card:hover{border-color:#e2e8f0;transform:translateY(-8px);box-shadow:0 25px 60px #00000014}.card-accent-bar{border-radius:10px;width:40px;height:6px;margin-bottom:1.5rem}.subfolder-row{gap:1.5rem;margin-bottom:3rem;padding-bottom:1rem;display:flex;overflow-x:auto}.subfolder-tile{background:var(--panel-bg);border:2px solid var(--border-light);cursor:pointer;color:var(--text-secondary);white-space:nowrap;border-radius:1.5rem;align-items:center;gap:.75rem;padding:1rem 1.75rem;font-weight:700;transition:all .2s;display:flex}.subfolder-tile:hover{border-color:var(--accent-color);color:var(--accent-color);transform:translateY(-2px)}.subfolder-tile.active{background:var(--accent-color);color:#fff;border-color:var(--accent-color);box-shadow:0 10px 20px #3b82f64d}.subfolder-delete-btn{cursor:pointer;color:inherit;opacity:.5;background:0 0;border:none;border-radius:50%;justify-content:center;align-items:center;margin-left:.25rem;padding:.25rem;transition:all .2s;display:flex}.subfolder-delete-btn:hover{color:#ef4444;opacity:1;background:#ef44441a}.subfolder-tile.active .subfolder-delete-btn{opacity:.8}.subfolder-tile.active .subfolder-delete-btn:hover{opacity:1;background:#fff3}.nav-links{color:var(--text-secondary);letter-spacing:.5px;gap:1.5rem;font-size:.85rem;font-weight:700;display:flex}.nav-link.active{color:#000;opacity:1}::-webkit-scrollbar{width:8px}::-webkit-scrollbar-track{background:0 0}::-webkit-scrollbar-thumb{background:#cbd5e1;border-radius:10px}.landing-screen{z-index:10000;background:#fff8eb;justify-content:center;align-items:center;display:flex;position:fixed;inset:0;overflow:hidden}.notebook-wrapper{justify-content:center;align-items:center;width:600px;height:600px;display:flex;position:relative}.cover-half{z-index:25;background:linear-gradient(135deg,#a5f3fc,#c084fc);width:50%;position:absolute;top:0;bottom:0;box-shadow:0 0 50px #0000001a}.cover-left{border-right:2px dashed #ffffff4d;border-radius:2rem 0 0 2rem;left:0}.cover-right{border-left:2px dashed #ffffff4d;border-radius:0 2rem 2rem 0;right:0}.open-notebook-btn{color:#000;cursor:pointer;background:#fc0;border:none;border-radius:2rem;padding:1rem 2.5rem;font-size:1.2rem;font-weight:800;transition:transform .2s,box-shadow .2s;animation:2s infinite btn-glow;box-shadow:0 10px 20px #ffcc004d}.open-notebook-btn:hover{transform:scale(1.05);box-shadow:0 15px 30px #fc06}.open-notebook-btn:active{transform:scale(.95)}@keyframes btn-glow{0%{box-shadow:0 0 20px #ffcc004d}50%{box-shadow:0 0 40px #fc09}to{box-shadow:0 0 20px #ffcc004d}}@keyframes slideUp{0%{opacity:0;transform:translateY(40px)}to{opacity:1;transform:translateY(0)}}.animate-slide{animation:.6s cubic-bezier(.23,1,.32,1) slideUp}.folder-general{background:linear-gradient(135deg,#667eea,#764ba2);box-shadow:0 20px 40px #667eea4d}.hover-scale{transition:transform .2s cubic-bezier(.4,0,.2,1)}.hover-scale:hover{transform:scale(1.03)}.blur-sm{filter:blur(4px);pointer-events:none}.toast{z-index:99999;border-radius:1rem;align-items:center;gap:.6rem;padding:.75rem 1.25rem;font-size:.9rem;font-weight:700;display:flex;position:fixed;bottom:2rem;right:2rem;box-shadow:0 10px 30px #0000001f}.toast-success{color:#fff;background:#000}.toast-error{color:#fff;background:#ef4444}.sidebar-menu{flex-direction:column;gap:.4rem;display:flex}.card-dsa{background:#ff8c00}.card-wap{background:#3a7bd5}.card-maths{background:#ff5f6d}.card-foai{background:#8e2de2}.card-general{background:#667eea}