:root {
    --background-color: #f4f4f4;
    --text-color: #333;
    --card-background: #ffffff;
    --card-hover-shadow: rgba(0, 0, 0, 0.1);
    --input-border: #ddd;
    --button-background: #4CAF50;
    --button-hover: #45a049;
    --alphabet-button-bg: #ffffff;
    --alphabet-button-text: #333;
    --alphabet-button-hover-bg: #4CAF50;
    --alphabet-button-hover-text: #ffffff;
    --author-card-bg: #f8f8f8;
    --section-background: #ffffff;
}

.dark-theme {
    --background-color: #1a1a1a;
    --text-color: #ffffff;
    --card-background: #2d2d2d;
    --card-hover-shadow: rgba(255, 255, 255, 0.1);
    --input-border: #444;
    --button-background: #4CAF50;
    --button-hover: #45a049;
    --alphabet-button-bg: #2d2d2d;
    --alphabet-button-text: #ffffff;
    --alphabet-button-hover-bg: #4CAF50;
    --alphabet-button-hover-text: #ffffff;
    --author-card-bg: #2d2d2d;
    --section-background: #2d2d2d;
}

body {
    font-family: Arial, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 20px;
    transition: background-color 0.3s, color 0.3s;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    position: relative;
}

h1 {
    text-align: center;
    color: var(--text-color);
    margin-bottom: 30px;
}

.search-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 20px;
    background-color: var(--section-background);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 5px var(--card-hover-shadow);
}

form {
    display: flex;
    gap: 10px;
    align-items: center;
}

select, input[type="text"], button {
    padding: 10px;
    border: 1px solid var(--input-border);
    border-radius: 4px;
    font-size: 16px;
    background-color: var(--alphabet-button-bg);
    color: var(--text-color);
}

input[type="text"] {
    width: 300px;
}

button {
    background-color: var(--button-background);
    color: white;
    border: none;
    cursor: pointer;
    padding: 10px 20px;
}

button:hover {
    background-color: var(--button-hover);
}

#results {
    background-color: var(--section-background);
    padding: 20px;
    border-radius: 8px;
    margin-top: 20px;
    box-shadow: 0 2px 5px var(--card-hover-shadow);
}

.book {
    background-color: var(--card-background);
    border-radius: 8px;
    box-shadow: 0 2px 5px var(--card-hover-shadow);
    overflow: hidden;
    transition: transform 0.2s;
    margin-bottom: 20px;
}

.book:hover {
    transform: translateY(-5px);
}

.book-content {
    display: flex;
    padding: 15px;
    gap: 15px;
}

.book-thumbnail {
    width: 100px;
    height: 150px;
    object-fit: cover;
    border-radius: 4px;
}

.book-info {
    flex: 1;
}

.book-info h3 {
    margin: 0 0 10px 0;
    color: var(--text-color);
}

.book-info p {
    margin: 5px 0;
    color: var(--text-color);
}

.description {
    font-style: italic;
    margin-top: 10px;
    line-height: 1.4;
}

#sort-order {
    margin-left: 10px;
}

@media (max-width: 768px) {
    .book-content {
        flex-direction: column;
    }
    
    .book-thumbnail {
        width: 100%;
        height: 200px;
    }
    
    .search-controls {
        flex-direction: column;
        align-items: stretch;
    }
    
    #language-select,
    #sort-order,
    #search-type {
        width: 100%;
        margin: 5px 0;
    }
}

.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    padding: 10px;
    font-size: 24px;
    background: none;
    border: none;
    cursor: pointer;
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.3s;
}

.theme-toggle:hover {
    background-color: var(--card-background);
}

#language-select {
    padding: 10px;
    border: 1px solid var(--input-border);
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
    margin-left: 10px;
}

/* Author Index Styles */
.author-index {
    margin: 20px 0;
    padding: 20px;
    background-color: var(--section-background);
    border-radius: 8px;
    box-shadow: 0 2px 5px var(--card-hover-shadow);
}

.author-index h2 {
    text-align: center;
    margin-bottom: 20px;
    color: var(--text-color);
}

.alphabet-filter {
    display: flex;
    flex-wrap: wrap;
    gap: 5px;
    justify-content: center;
    margin-bottom: 20px;
    padding: 10px;
    background-color: var(--card-background);
    border-radius: 4px;
}

.alphabet-filter button {
    width: 35px;
    height: 35px;
    border: 1px solid var(--input-border);
    border-radius: 4px;
    background-color: var(--alphabet-button-bg);
    color: var(--alphabet-button-text);
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.alphabet-filter button:hover {
    background-color: var(--alphabet-button-hover-bg);
    color: var(--alphabet-button-hover-text);
    border-color: var(--button-background);
}

.author-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
    padding: 20px 0;
}

.author-card {
    background-color: var(--author-card-bg);
    padding: 15px;
    border-radius: 4px;
    text-align: center;
    transition: transform 0.2s;
    box-shadow: 0 2px 5px var(--card-hover-shadow);
}

.author-card:hover {
    transform: translateY(-3px);
}

.author-card h3 {
    margin: 0 0 10px 0;
    font-size: 16px;
    color: var(--text-color);
}

.author-card button {
    background-color: var(--button-background);
    color: white;
    border: none;
    padding: 8px 15px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    transition: background-color 0.2s;
}

.author-card button:hover {
    background-color: var(--button-hover);
}

@media (max-width: 768px) {
    .alphabet-filter {
        gap: 3px;
    }

    .alphabet-filter button {
        width: 30px;
        height: 30px;
        font-size: 14px;
    }

    .author-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }
}

/* Loading and Error States */
.loading, .error {
    text-align: center;
    padding: 20px;
    color: var(--text-color);
}

.error {
    color: #ff4444;
}

/* Author Index Wrapper and Toggle */
.author-index-wrapper {
    margin: 20px 0;
}

.author-index-toggle {
    width: 100%;
    padding: 15px;
    background-color: var(--section-background);
    border: none;
    border-radius: 8px;
    color: var(--text-color);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 16px;
    box-shadow: 0 2px 5px var(--card-hover-shadow);
    transition: background-color 0.3s;
}

.author-index-toggle:hover {
    background-color: var(--author-card-bg);
}

.toggle-icon {
    font-size: 12px;
    transition: transform 0.3s;
}

/* Author Index Collapsible Section */
.author-index {
    margin-top: 10px;
    background-color: var(--section-background);
    border-radius: 8px;
    box-shadow: 0 2px 5px var(--card-hover-shadow);
    overflow: hidden;
    transition: max-height 0.5s ease-in-out, opacity 0.3s ease-in-out, margin-top 0.3s ease-in-out;
    max-height: 2000px;
    opacity: 1;
}

.author-index.collapsed {
    max-height: 0;
    opacity: 0;
    margin-top: 0;
    pointer-events: none;
}

/* Ensure content is properly padded */
.author-index > * {
    padding: 20px;
}

.author-index .alphabet-filter {
    margin: 0 20px 20px;
}

/* Animation for toggle icon */
.author-index-toggle .toggle-icon {
    transition: transform 0.3s ease;
}

.author-index.collapsed + .author-index-toggle .toggle-icon {
    transform: rotate(180deg);
}

/* Adjust spacing for collapsed state */
.author-index-wrapper + #results {
    margin-top: 20px;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .author-index-toggle {
        padding: 12px;
        font-size: 14px;
    }

    .author-index > * {
        padding: 15px;
    }
}