:root{--color-primary: #1e88e5;--color-secondary: #424242;--color-background: #f4f4f9;--color-light-gray: #e0e0e0;--color-white: #ffffff;--color-error: #d32f2f;--spacing-unit: 1rem}*{box-sizing:border-box;margin:0;padding:0}body{font-family:Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background-color:var(--color-background);color:var(--color-secondary);line-height:1.6}h1,h2,h3{color:var(--color-secondary);margin-bottom:var(--spacing-unit)}.app-container{display:flex;flex-direction:column;min-height:100vh}.main-content{flex-grow:1;width:90%;margin:2rem auto;padding:0 1rem;text-align:center}.app-header{background-color:var(--color-white);padding:1.5rem 1rem;box-shadow:0 2px 4px #0000000d;text-align:center}.app-header h1{margin-bottom:.25rem;color:var(--color-primary)}.app-footer{text-align:center;padding:1rem;margin-top:2rem;border-top:1px solid var(--color-light-gray);color:#757575;font-size:.85rem}.app-footer a{color:var(--color-primary);text-decoration:none}.app-footer a:hover{text-decoration:underline}.search-bar-container{margin:2rem 0;text-align:center}.search-input{width:100%;max-width:600px;padding:.75rem 1rem;font-size:1rem;border:2px solid var(--color-light-gray);border-radius:8px;transition:border-color .3s,box-shadow .3s}.search-input:focus{border-color:var(--color-primary);box-shadow:0 0 0 3px #1e88e533;outline:none}.button{padding:.5rem 1rem;border:none;border-radius:4px;cursor:pointer;font-weight:700;text-decoration:none;display:inline-block;text-align:center;transition:background-color .2s,opacity .2s;font-size:.9rem}.button-view{background-color:#64b5f6;color:var(--color-white)}.button-view:hover{background-color:#42a5f5}.button-favorite{background-color:var(--color-light-gray);color:var(--color-secondary)}.button-favorite:hover{background-color:#bdbdbd}.favorite-active{background-color:var(--color-primary);color:var(--color-white)}.favorite-active:hover{background-color:#1565c0}.button-page{background-color:var(--color-white);border:1px solid var(--color-light-gray);color:var(--color-secondary);min-width:100px}.button-page:hover:not(:disabled){background-color:var(--color-light-gray)}.button-page:disabled{opacity:.5;cursor:not-allowed}.button-remove{background-color:var(--color-error);color:var(--color-white);padding:.3rem .6rem;font-size:.8rem}.button-remove:hover{background-color:#c62828}.button-view-sm{background-color:#a5d6a7;color:var(--color-secondary);padding:.3rem .6rem;font-size:.8rem;margin-right:.5rem}.button-view-sm:hover{background-color:#81c784}.status-message{text-align:center;padding:1rem 0;font-style:italic;color:#757575}.search-info{text-align:center;margin-bottom:1rem;color:#4caf50;font-weight:500}.results-grid{display:grid;gap:2rem;padding:1rem 0;grid-template-columns:1fr}@media(min-width:768px){.results-grid{grid-template-columns:repeat(2,1fr)}}@media(min-width:1024px){.results-grid{grid-template-columns:repeat(3,1fr)}}.book-card{background-color:var(--color-white);border-radius:8px;box-shadow:0 4px 12px #00000014;padding:1.5rem;display:flex;flex-direction:column;transition:transform .2s,box-shadow .2s;height:100%}.book-card:hover{transform:translateY(-5px);box-shadow:0 6px 16px #0000001f}.book-cover-container{text-align:center;margin-bottom:1rem;height:200px;display:flex;align-items:center;justify-content:center}.book-cover{max-height:100%;width:auto;border-radius:4px;box-shadow:0 2px 4px #0000001a}.book-details{flex-grow:1;margin-bottom:1rem}.book-title{font-size:1.25rem;margin-top:0;margin-bottom:.5rem;color:var(--color-primary)}.book-details p{font-size:.9rem;margin-bottom:.3rem;color:#555}.book-author{font-style:italic}.book-subjects{font-size:.85rem!important;color:#616161}.card-actions{display:flex;justify-content:space-between;align-items:center;margin-top:auto;padding-top:.5rem;border-top:1px solid var(--color-light-gray)}.pagination-controls{display:flex;justify-content:center;align-items:center;gap:1.5rem;margin:3rem 0 2rem}.page-info{font-weight:700;color:var(--color-secondary)}.loading-spinner{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:3rem 0}.spinner{border:4px solid rgba(0,0,0,.1);border-top:4px solid var(--color-primary);border-radius:50%;width:40px;height:40px;animation:spin 1s linear infinite;margin-bottom:1rem}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.favorites-section{margin-top:4rem;padding:2rem;background-color:var(--color-white);border-radius:8px;box-shadow:0 2px 8px #0000000d}.favorites-section h2{border-bottom:2px solid var(--color-primary);padding-bottom:.5rem;margin-bottom:1.5rem;color:var(--color-primary)}.favorites-list{display:flex;flex-wrap:wrap;gap:1.5rem}.favorite-item{display:flex;width:100%;padding:.75rem;border:1px solid var(--color-light-gray);border-radius:6px;background-color:#fafafa;align-items:center}@media(min-width:600px){.favorite-item{width:calc(50% - .75rem)}}@media(min-width:900px){.favorite-item{width:calc(33.333% - 1rem)}}.favorite-cover img{height:60px;width:auto;border-radius:2px;margin-right:1rem}.favorite-details{flex-grow:1}.favorite-title{font-size:1rem;margin:0;line-height:1.3;color:var(--color-secondary)}.favorite-author{font-size:.8rem;color:#757575;margin-bottom:.5rem}.favorite-actions{display:flex;gap:.5rem}.empty-state-message{text-align:center;padding:1rem;color:#757575;font-style:italic}