/* 左右布局容器 */
.layout-container {
    display: flex; max-width: 1400px; margin: 30px auto;
    padding: 0 20px; gap: 30px; align-items: flex-start;
}

/* 左侧边栏 */
.sidebar {
    width: 240px; background: white; border-radius: 10px;
    padding: 20px; box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    flex-shrink: 0; position: sticky; top: 80px;
    max-height: calc(100vh - 100px); overflow-y: auto;
}

/* 侧边栏各分组小标题（可折叠） */
.sidebar-section {
    display: flex; justify-content: space-between; align-items: center;
    font-size: 0.85em; font-weight: bold; color: #7f8c8d;
    text-transform: uppercase; letter-spacing: 0.05em;
    margin: 18px 0 8px; padding-bottom: 5px;
    border-bottom: 1px solid #eee;
    cursor: pointer; user-select: none;
}
.sidebar-section:first-child { margin-top: 0; }
.sidebar-section:hover { color: #2c3e50; }
.section-arrow {
    font-size: 0.9em; transition: transform 0.2s; display: inline-block;
}

/* 标签列表 */
.tag-list {
    display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 4px;
}
.tag-item {
    padding: 4px 10px; border-radius: 12px; background: #f1f2f6;
    color: #2c3e50; font-size: 0.85em; transition: 0.2s;
    cursor: pointer; user-select: none; border: 1px solid transparent;
}
.tag-item:hover { background: #e2e6ea; }
.tag-item.include { background: #2c3e50; color: white; }
.tag-item.exclude { background: #e74c3c; color: white; }

/* 标签操作提示 */
.tag-hint {
    font-size: 0.75em; color: #bbb; margin-top: 5px; margin-bottom: 2px;
}

/* 书单列表 */
.group-list { display: flex; flex-direction: column; gap: 5px; margin-bottom: 4px; }
.group-item {
    padding: 6px 10px; border-radius: 8px; background: #f1f2f6;
    color: #2c3e50; font-size: 0.9em; cursor: pointer; user-select: none;
    transition: 0.2s; border: 1px solid transparent;
    white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.group-item:hover { background: #e2e6ea; }
.group-item.active { background: #2c3e50; color: white; }

/* 排序按钮组 */
.sort-options { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 4px; }
.sort-btn {
    padding: 4px 10px; border-radius: 12px; border: 1px solid #ddd;
    background: white; color: #555; font-size: 0.85em; cursor: pointer;
    transition: 0.2s; user-select: none;
}
.sort-btn:hover { border-color: #2c3e50; color: #2c3e50; }
.sort-btn.active { background: #2c3e50; color: white; border-color: #2c3e50; }
.sort-order-btn {
    padding: 4px 10px; border-radius: 12px; border: 1px solid #ddd;
    background: white; color: #888; font-size: 0.85em; cursor: pointer;
    transition: 0.2s; user-select: none; margin-top: 2px;
}
.sort-order-btn:hover { border-color: #7f8c8d; color: #2c3e50; }

/* 清除全部按钮 */
.clear-all-btn {
    display: block; width: 100%; margin-top: 18px; padding: 7px 0;
    background: white; color: #e74c3c; border: 1px solid #e74c3c;
    border-radius: 8px; font-size: 0.9em; cursor: pointer; transition: 0.2s;
    text-align: center;
}
.clear-all-btn:hover { background: #e74c3c; color: white; }

/* 书单 Banner */
.group-banner {
    background: #f8f9fa; border-left: 4px solid #2c3e50;
    border-radius: 0 8px 8px 0; padding: 14px 18px; margin-bottom: 20px;
}
.group-banner-name {
    font-size: 1.2em; font-weight: bold; color: #2c3e50; margin-bottom: 4px;
}
.group-banner-desc { font-size: 0.95em; color: #666; line-height: 1.6; }

/* 分页 */
.pagination {
    display: flex; justify-content: center; align-items: center;
    gap: 12px; margin-top: 30px; padding: 10px 0;
}
.page-link {
    padding: 6px 14px; background: #2c3e50; color: white;
    border-radius: 6px; text-decoration: none; font-size: 0.95em; transition: 0.2s;
}
.page-link:hover { background: #1a252f; }
.page-disabled { padding: 6px 14px; color: #aaa; font-size: 0.95em; cursor: default; }
.page-current { padding: 6px 10px; font-size: 0.95em; color: #555; }

/* 右侧主内容区 */
.main-content { flex-grow: 1; min-width: 0; }
.shelf-grid { margin: 0; max-width: 100%; padding: 0; }
.book-tags { font-size: 0.8em; color: #3498db; margin-bottom: 5px; }

@media (max-width: 768px) {
    .layout-container { flex-direction: column; }
    .sidebar { width: 100%; position: static; max-height: none; }
}