/* 性能优化：设置现代属性选择器 */
:root {
    --calibre-primary: #0073aa;
    --calibre-primary-dark: #005177;
    --calibre-text: #333;
    --calibre-text-light: #666;
    --calibre-border: #ddd;
    --calibre-bg-light: #f7f7f7;
    --calibre-bg: #fff;
    --calibre-shadow: 0 1px 3px rgba(0,0,0,0.1);
    --calibre-shadow-hover: 0 5px 15px rgba(0,0,0,0.1);
    --calibre-transition: 0.2s ease;
    --calibre-radius: 8px;
    --calibre-read: #5D5CDE; /* 新增：在线阅读按钮颜色 */
    --calibre-read-dark: #4a49b7; /* 新增：在线阅读按钮悬停颜色 */
}

/* 书籍描述样式 */
.book-description {
    font-size: 0.9em;
    margin-top: 8px;
    color: var(--calibre-text);
    overflow: hidden;
    position: relative;
    line-height: 1.4;
    contain: paint; /* 性能优化：减少重绘区域 */
}

.book-description.collapsed {
    max-height: 80px;
    -webkit-mask-image: linear-gradient(to bottom, black 60%, transparent 100%);
    mask-image: linear-gradient(to bottom, black 60%, transparent 100%);
}

.description-toggle {
    display: inline-block;
    margin-top: 5px;
    color: var(--calibre-primary);
    cursor: pointer;
    font-size: 0.85em;
    text-decoration: underline;
    user-select: none; /* 性能优化：防止意外选择 */
}

.description-toggle:hover {
    color: var(--calibre-primary-dark);
}

/* 新增：书籍操作区域 - 包含下载和在线阅读按钮 */
.book-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 10px;
    align-items: flex-start;
}

/* 下载链接样式 */
.book-downloads {
    font-size: 0.9em;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
}

.download-label {
    margin-right: 5px;
    color: #555;
}

.download-links {
    display: flex;
    flex-wrap: wrap;
}

.download-link {
    display: inline-block;
    margin: 2px 5px 2px 0;
    padding: 3px 8px;
    background-color: var(--calibre-primary);
    color: white;
    border-radius: 3px;
    text-decoration: none;
    font-size: 0.85em;
    transition: background-color var(--calibre-transition);
    transform: translateZ(0); /* 性能优化：启用GPU加速 */
}

.download-link:hover {
    background-color: var(--calibre-primary-dark);
    color: white;
    text-decoration: none;
}

/* 新增：在线阅读按钮样式 */
.book-read-online {
    display: flex;
    align-items: center;
}

.read-online-link {
    display: inline-block;
    padding: 3px 10px;
    background-color: var(--calibre-read);
    color: white;
    border-radius: 3px;
    text-decoration: none;
    font-size: 0.85em;
    transition: all var(--calibre-transition);
    transform: translateZ(0); /* 性能优化：启用GPU加速 */
}

.read-online-link:hover {
    background-color: var(--calibre-read-dark);
    color: white;
    text-decoration: none;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.15);
}

/* 搜索表单样式 */
.calibre-search-form {
    margin-bottom: 20px;
    padding: 15px;
    background: var(--calibre-bg-light);
    border-radius: var(--calibre-radius);
    box-shadow: var(--calibre-shadow);
    contain: content; /* 性能优化 */
}

.calibre-search-form .search-input-wrapper {
    display: flex;
    margin-bottom: 10px;
}

.calibre-search-form input[type="text"] {
    flex: 1;
    padding: 8px 12px;
    border: 1px solid var(--calibre-border);
    border-radius: 4px 0 0 4px;
    font-size: 16px;
    /* 性能优化：减少输入时的重绘 */
    will-change: contents;
    background-color: var(--calibre-bg);
}

.calibre-search-form button {
    padding: 8px 15px;
    background: var(--calibre-primary);
    color: white;
    border: none;
    border-radius: 0 4px 4px 0;
    cursor: pointer;
    transition: background-color var(--calibre-transition);
    position: relative; /* 用于脉冲动画 */
    overflow: hidden; /* 用于脉冲动画 */
}

.calibre-search-form button:hover {
    background: var(--calibre-primary-dark);
}

/* 新增：搜索按钮脉冲动画 */
.calibre-search-button.pulsing::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 5px;
    height: 5px;
    background: rgba(255, 255, 255, 0.7);
    opacity: 0;
    border-radius: 100%;
    transform: scale(1) translate(-50%, -50%);
    transform-origin: 0 0;
    animation: pulse 1.5s infinite ease-out;
}

@keyframes pulse {
    0% {
        transform: scale(0) translate(-50%, -50%);
        opacity: 1;
    }
    80%, 100% {
        transform: scale(25) translate(-50%, -50%);
        opacity: 0;
    }
}

/* 搜索选项样式 - 新增 */
.search-options {
    display: flex;
    align-items: center;
    margin-bottom: 10px;
    font-size: 0.9em;
}

.search-options label {
    margin-right: 8px;
    color: var(--calibre-text-light);
}

.calibre-page-size {
    padding: 5px 8px;
    border: 1px solid var(--calibre-border);
    border-radius: 4px;
    font-size: 0.9em;
    background: var(--calibre-bg);
}

.calibre-search-loading {
    display: none;
    margin: 10px 0;
    text-align: center;
    color: var(--calibre-text-light);
}

.calibre-search-loading .spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid rgba(0, 0, 0, 0.1);
    border-left-color: var(--calibre-primary);
    border-radius: 50%;
    animation: calibre-spinner 1s linear infinite;
    margin-right: 5px;
    vertical-align: middle;
    will-change: transform; /* 性能优化：提前告知浏览器transform会变化 */
}

@keyframes calibre-spinner {
    to {transform: rotate(360deg);}
}

.calibre-no-results,
.calibre-search-error {
    padding: 10px;
    background: #f0f0f1;
    border-left: 4px solid #72aee6;
    margin: 10px 0;
}

.calibre-search-error {
    border-left-color: #d63638;
    background: #ffebe9;
    color: #d63638;
}

/* 列表布局样式 */
.calibre-books-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin: 20px 0;
    contain: content; /* 性能优化 */
}

.calibre-book-list-item {
    display: flex;
    border: 1px solid var(--calibre-border);
    border-radius: var(--calibre-radius);
    padding: 15px;
    background: var(--calibre-bg);
    transition: box-shadow var(--calibre-transition);
    gap: 20px;
    contain: content; /* 性能优化 */
    transform: translateZ(0); /* 性能优化：启用GPU加速 */
}

.calibre-book-list-item:hover {
    box-shadow: var(--calibre-shadow-hover);
}

.book-list-cover {
    flex: 0 0 120px;
    display: flex;
    align-items: center;
    justify-content: center;
    contain: strict; /* 性能优化：严格限制重排区域 */
}

.book-list-cover img {
    max-width: 120px;
    max-height: 180px;
    width: auto;
    border-radius: 5px;
    box-shadow: 0 3px 8px rgba(0,0,0,0.15);
    transform: translateZ(0); /* 性能优化：启用GPU加速 */
}

.book-cover-placeholder {
    width: 120px;
    height: 180px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #f0f0f0;
    color: #999;
    font-size: 0.8em;
    border-radius: 5px;
    text-align: center;
}

.book-list-details {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.book-title {
    margin: 0 0 5px 0;
    font-size: 1.1em;
    line-height: 1.3;
    text-rendering: optimizeSpeed; /* 性能优化：优化文本渲染速度 */
}

.book-author {
    font-size: 0.9em;
    color: var(--calibre-text-light);
    margin-bottom: 3px;
}

.book-format {
    font-size: 0.8em;
    color: #888;
    margin-bottom: 5px;
}

/* 控制栏样式 */
.calibre-controls-bar {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    margin-bottom: 15px;
    flex-wrap: wrap;
    gap: 10px;
    contain: layout; /* 性能优化：控制布局变化范围 */
}

.calibre-result-count {
    font-size: 0.9em;
    color: var(--calibre-text-light);
}

/* 分页控件样式 */
.calibre-pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 20px 0;
    flex-wrap: wrap;
    gap: 5px;
    contain: content; /* 性能优化 */
}

.pagination-link {
    display: inline-block;
    padding: 5px 10px;
    border: 1px solid var(--calibre-border);
    border-radius: 4px;
    color: var(--calibre-primary);
    text-decoration: none;
    background: var(--calibre-bg);
    min-width: 15px;
    text-align: center;
    transition: background-color var(--calibre-transition);
    user-select: none; /* 性能优化：防止意外选择 */
    contain: layout; /* 性能优化：控制布局变化范围 */
}

.pagination-link:hover:not(.disabled):not(.current) {
    background-color: #f0f0f0;
    color: var(--calibre-primary-dark);
}

.pagination-link.current {
    background-color: var(--calibre-primary);
    color: white;
    border-color: var(--calibre-primary);
    cursor: default;
}

.pagination-link.disabled {
    color: #999;
    cursor: not-allowed;
}

.pagination-ellipsis {
    margin: 0 5px;
    color: var(--calibre-text-light);
}

/* 无限滚动加载指示器 */
.calibre-infinite-loader {
    text-align: center;
    padding: 15px;
    color: var(--calibre-text-light);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 10px 0;
}

.calibre-infinite-loader .spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid rgba(0, 0, 0, 0.1);
    border-left-color: var(--calibre-primary);
    border-radius: 50%;
    animation: calibre-spinner 1s linear infinite;
    margin-right: 10px;
    will-change: transform; /* 性能优化 */
}

.calibre-no-more-books {
    text-align: center;
    color: var(--calibre-text-light);
    margin: 15px 0;
    font-style: italic;
}

/* 新增的搜索结果头部样式 */
.calibre-search-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--calibre-border);
    contain: layout; /* 性能优化 */
}

.calibre-search-info {
    font-size: 1em;
    color: var(--calibre-text);
    font-weight: 500;
}

.calibre-clear-search {
    background: #f0f0f0;
    border: 1px solid var(--calibre-border);
    border-radius: 4px;
    padding: 4px 10px;
    font-size: 0.85em;
    cursor: pointer;
    transition: all var(--calibre-transition);
    user-select: none; /* 性能优化 */
}

.calibre-clear-search:hover {
    background: #e0e0e0;
}

/* 已删除懒加载相关样式 */

/* 性能优化：动画优化 */
@media (prefers-reduced-motion: reduce) {
    .calibre-book-list-item:hover {
        transform: none;
    }
    .calibre-search-loading .spinner,
    .calibre-infinite-loader .spinner {
        animation-duration: 2s;
    }
    .calibre-search-button.pulsing::after {
        animation: none;
    }
}

/* 响应式调整 */
@media (max-width: 768px) {
    .calibre-book-list-item {
        flex-direction: column;
    }
    
    .book-list-cover {
        margin-bottom: 15px;
        width: 100%;
    }
    
    .book-list-cover img {
        max-width: 150px;
    }
    
    .calibre-controls-bar {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .search-options {
        flex-wrap: wrap;
    }
    
    /* 新增：移动端按钮样式优化 */
    .book-actions {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .book-read-online {
        margin-top: 5px;
    }
    
    .read-online-link {
        padding: 6px 12px; /* 增大触摸区域 */
    }
}

/* 新增：正在加载书籍的占位符 */
.book-placeholder {
    height: 100%;
    background: linear-gradient(90deg, var(--calibre-bg-light) 0%, var(--calibre-bg) 50%, var(--calibre-bg-light) 100%);
    background-size: 200% 100%;
    animation: placeholder-pulse 1.5s infinite;
    border-radius: var(--calibre-radius);
    contain: strict; /* 性能优化 */
}

@keyframes placeholder-pulse {
    0% {
        background-position: 0% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

/* 暗色模式支持 */
@media (prefers-color-scheme: dark) {
    :root {
        --calibre-primary: #3a5b70;
        --calibre-primary-dark: #4d7999;
        --calibre-text: #f0f0f0;
        --calibre-text-light: #aaa;
        --calibre-border: #444;
        --calibre-bg-light: #333;
        --calibre-bg: #2c2c2c;
        --calibre-read: #8e8dff; /* 暗色模式在线阅读按钮颜色 */
        --calibre-read-dark: #7a79e6; /* 暗色模式在线阅读按钮悬停颜色 */
    }
    
    .calibre-book-list-item {
        background: var(--calibre-bg);
        border-color: var(--calibre-border);
    }
    
    .book-author {
        color: var(--calibre-text-light);
    }
    
    .book-format {
        color: #999;
    }
    
    .book-description {
        color: var(--calibre-text);
    }
    
    .download-label {
        color: var(--calibre-text-light);
    }
    
    /* 新增：暗色模式在线阅读按钮 */
    .read-online-link {
        background-color: var(--calibre-read);
        color: #222;
    }
    
    .read-online-link:hover {
        background-color: var(--calibre-read-dark);
        box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    }
    
    .calibre-no-results,
    .calibre-search-error {
        background: #333;
        color: var(--calibre-text);
    }
    
    .calibre-search-error {
        color: #ff8a8a;
        background: #3a2a2a;
    }
    
    .pagination-link {
        background: var(--calibre-bg);
        border-color: var(--calibre-border);
        color: #72aee6;
    }
    
    .pagination-link:hover:not(.disabled):not(.current) {
        background: #3a3a3a;
    }
    
    .book-cover-placeholder {
        background: #383838;
        color: var(--calibre-text-light);
    }
    
    .book-placeholder {
        background: linear-gradient(90deg, #333 0%, #3a3a3a 50%, #333 100%);
        background-size: 200% 100%;
    }
    
    /* 无限滚动加载器 - 暗色模式 */
    .calibre-infinite-loader .spinner {
        border-color: rgba(255, 255, 255, 0.1);
        border-left-color: #72aee6;
    }
    
    .calibre-clear-search {
        background: #3a3a3a;
        border-color: #555;
        color: var(--calibre-text);
    }
    
    .calibre-clear-search:hover {
        background: #444;
    }
    
    .calibre-search-form input[type="text"],
    .calibre-page-size {
        background: #222;
        border-color: var(--calibre-border);
        color: var(--calibre-text);
    }
}