:root{--primary-color: #3498db;--secondary-color: #2980b9;--danger-color: #e74c3c;--success-color: #2ecc71;--light-gray: #f5f5f5;--dark-gray: #333;--border-color: #ddd}*{box-sizing:border-box;margin:0;padding:0;font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif}body{background-color:#f9f9f9;color:#333;line-height:1.6}.app{max-width:1200px;margin:0 auto;padding:2rem}h1{text-align:center;color:var(--dark-gray);margin-bottom:2rem;font-size:2.5rem}h2{color:var(--secondary-color);margin-bottom:1.5rem;font-size:1.8rem}.form-container{background:#fff;padding:2rem;border-radius:8px;box-shadow:0 2px 10px #0000001a;margin-bottom:2rem}.book-form{display:flex;flex-direction:column;gap:1.2rem}.form-group{display:flex;flex-direction:column;gap:.5rem}.form-group label{font-weight:600;color:#555}.form-group input{padding:.8rem;border:1px solid var(--border-color);border-radius:4px;font-size:1rem;transition:border-color .3s ease}.form-group input:focus{outline:none;border-color:var(--primary-color);box-shadow:0 0 0 2px #3498db33}button{padding:.8rem 1.5rem;border:none;border-radius:4px;font-size:1rem;font-weight:600;cursor:pointer;transition:all .3s ease}.submit-btn{background-color:var(--primary-color);color:#fff;margin-top:1rem}.submit-btn:hover{background-color:var(--secondary-color)}.cancel-btn{background-color:#95a5a6;color:#fff;margin-left:1rem}.cancel-btn:hover{background-color:#7f8c8d}.books-container{background:#fff;padding:2rem;border-radius:8px;box-shadow:0 2px 10px #0000001a}.no-books{text-align:center;color:#777;font-style:italic;padding:2rem 0}.books-table{width:100%;border-collapse:collapse;margin-top:1rem}.books-table th,.books-table td{padding:1rem;text-align:left;border-bottom:1px solid var(--border-color)}.books-table th{background-color:var(--light-gray);font-weight:600;color:var(--dark-gray)}.books-table tr:hover{background-color:#f9f9f9}.actions{display:flex;gap:.5rem}.edit-btn{background-color:#f39c12;color:#fff;padding:.5rem 1rem;font-size:.9rem}.edit-btn:hover{background-color:#d68910}.delete-btn{background-color:var(--danger-color);color:#fff;padding:.5rem 1rem;font-size:.9rem}.delete-btn:hover{background-color:#c0392b}@media (max-width: 768px){.app{padding:1rem}.form-container,.books-container{padding:1.5rem}.books-table{display:block;overflow-x:auto}.actions{flex-direction:column;gap:.5rem}.cancel-btn{margin-left:0;margin-top:.5rem}}