:root {
    /* 亮色模式变量 */
    --bg-body: #f8f9fa;
    --bg-sidebar: #ffffff;
    --bg-card: #ffffff;
    --bg-card-hover: #ffffff;
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --border-color: #e5e7eb;
    --primary-color: #3b82f6;
    --primary-light: #eff6ff;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --sidebar-width: 260px;
    --header-height: 64px;
    --transition-fast: 0.2s ease;
}

@media (prefers-color-scheme: dark) {
    :root {
        /* 深色模式变量 */
        --bg-body: #0f172a;
        --bg-sidebar: #1e293b;
        --bg-card: #1e293b;
        --bg-card-hover: #263345;
        --text-primary: #f1f5f9;
        --text-secondary: #94a3b8;
        --border-color: #334155;
        --primary-color: #60a5fa;
        --primary-light: #1e3a8a;
        --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
        --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.3), 0 2px 4px -2px rgb(0 0 0 / 0.3);
    }
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', 'Noto Sans SC', sans-serif;
    color: var(--text-primary);
    background-color: var(--bg-body);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
}

/* 布局容器 */
.app-container {
    display: flex;
    min-height: 100vh;
}

/* 侧边栏样式 */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--bg-sidebar);
    border-right: 1px solid var(--border-color);
    position: fixed;
    height: 100vh;
    left: 0;
    top: 0;
    z-index: 50;
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
    transition: transform var(--transition-fast);
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 2rem;
}

.logo i {
    color: var(--primary-color);
}

.nav-menu {
    flex: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-weight: 500;
    transition: all var(--transition-fast);
    cursor: pointer;
}

.nav-item:hover,
.nav-item.active {
    background-color: var(--primary-light);
    color: var(--primary-color);
}

.nav-item i {
    font-size: 1.25rem;
}

.sidebar-footer {
    padding-top: 1rem;
    margin-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.footer-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
    transition: color var(--transition-fast);
}

.footer-link:hover {
    color: var(--primary-color);
}

/* 主内容区样式 */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    display: flex;
    flex-direction: column;
}

.top-header {
    height: var(--header-height);
    background-color: var(--bg-body);
    /* 透明或背景色 */
    backdrop-filter: blur(8px);
    position: sticky;
    top: 0;
    z-index: 40;
    display: flex;
    align-items: center;
    padding: 0 2rem;
    border-bottom: 1px solid transparent;
}

.search-bar {
    position: relative;
    max-width: 400px;
    width: 100%;
}

.search-bar i {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

.search-bar input {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 2.75rem;
    border-radius: 2rem;
    border: 1px solid var(--border-color);
    background-color: var(--bg-sidebar);
    color: var(--text-primary);
    font-size: 0.875rem;
    outline: none;
    transition: all var(--transition-fast);
}

.search-bar input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px var(--primary-light);
}

.content-wrapper {
    padding: 2rem;
    flex: 1;
}

.category-section {
    margin-bottom: 3rem;
}

.category-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.category-title i {
    color: var(--text-secondary);
}

/* 卡片网格 */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
}

.card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.25rem;
    display: flex;
    gap: 1rem;
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    background-color: var(--bg-card-hover);
    border-color: var(--primary-color);
}

.card-logo {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    background-color: var(--bg-body);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    overflow: hidden;
}

.card-logo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.card-content {
    flex: 1;
    min-width: 0;
    /* 解决flex子项截断问题 */
}

.card-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.card-desc {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.page-footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* 移动端适配 */
@media (max-width: 768px) {
    :root {
        --sidebar-width: 0px;
    }

    .sidebar {
        transform: translateX(-100%);
    }

    .main-content {
        margin-left: 0;
    }

    .top-header {
        padding: 0 1rem;
    }

    .card-grid {
        grid-template-columns: 1fr;
    }
}

/* 二级分类样式 */
.sub-category {
    margin-bottom: 2rem;
}

.sub-category-title {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 1rem;
    padding-left: 0.5rem;
    border-left: 3px solid var(--primary-color);
}
/* Header Controls */
.header-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-left: auto;
}

#admin-actions {
    display: flex;
    gap: 0.5rem;
}

.hidden {
    display: none !important;
}

/* Buttons */
.btn-icon {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.btn-icon:hover, .btn-icon.active {
    color: var(--primary-color);
    background-color: var(--primary-light);
}

.btn-primary, .btn-secondary {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    cursor: pointer;
    border: none;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    opacity: 0.9;
}

.btn-secondary {
    background-color: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background-color: var(--bg-card-hover);
}

/* Edit/Delete Actions on Card */
.admin-mode .card {
    cursor: default; /* 编辑模式下点击卡片不跳转，而是管理 */
}

.card-actions {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    display: flex;
    gap: 0.25rem;
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.admin-mode .card:hover .card-actions,
.card-actions.visible {
    opacity: 1;
}

.btn-card-action {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    border: 1px solid var(--border-color);
    background: var(--bg-card);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-secondary);
    font-size: 1rem;
}

.btn-card-action:hover {
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-card-action.delete:hover {
    color: #ef4444;
    border-color: #ef4444;
}


/* Modal Styles */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(4px);
}

.modal {
    background-color: var(--bg-card);
    width: 90%;
    max-width: 500px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    animation: slideIn 0.3s ease;
    border: 1px solid var(--border-color);
}

@keyframes slideIn {
    from { transform: translateY(20px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.modal-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
}

.btn-close {
    background: none;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    color: var(--text-secondary);
}

.modal-body {
    padding: 1.5rem;
}

.form-group {
    margin-bottom: 1.25rem;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.form-group input, .form-group select {
    width: 100%;
    padding: 0.625rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    background-color: var(--bg-body);
    color: var(--text-primary);
    font-size: 1rem;
    outline: none;
    transition: border-color var(--transition-fast);
}

.form-group input:focus, .form-group select:focus {
    border-color: var(--primary-color);
}

.modal-footer {
    padding: 1rem 1.5rem;
    background-color: var(--bg-sidebar);
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
    border-bottom-left-radius: var(--radius-lg);
    border-bottom-right-radius: var(--radius-lg);
}

.btn-text {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-weight: 500;
}

.btn-text:hover {
    color: var(--text-primary);
}

/* Category Management */

/* Sidebar Actions */
.sidebar-actions {
    display: none; /* hidden by default */
    align-items: center;
    gap: 0.25rem;
    margin-left: auto;
}

.admin-mode .nav-item {
    padding-right: 0.5rem;
}

.admin-mode .nav-item .sidebar-actions {
    display: flex;
}

.btn-sidebar-action {
    background: none;
    border: none;
    color: var(--text-secondary); /* 默认淡色，不抢眼 */
    cursor: pointer;
    font-size: 1rem;
    padding: 2px;
    border-radius: 4px;
    opacity: 0.6;
    transition: all var(--transition-fast);
}

.btn-sidebar-action:hover {
    color: var(--primary-color);
    opacity: 1;
    background-color: var(--bg-body);
}

.btn-sidebar-action.delete:hover {
    color: #ef4444;
}

/* Sidebar Add Button */
.sidebar-add-btn {
    display: none;
    width: 100%;
    margin-top: 1rem;
    padding: 0.75rem;
    border: 1px dashed var(--border-color);
    background: transparent;
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    cursor: pointer;
    text-align: center;
    font-size: 0.875rem;
    transition: all var(--transition-fast);
}

.admin-mode .sidebar-add-btn {
    display: block;
}

.sidebar-add-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    background-color: var(--primary-light);
}

/* Subcategory Actions */
.subcategory-header {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
    padding-left: 0.5rem;
    border-left: 3px solid var(--primary-color);
}

.sub-category-title {
    margin-bottom: 0; /* remove old margin */
    border-left: none; /* remove old border */
    padding-left: 0;
}

.sub-actions {
    display: none;
    margin-left: 0.75rem;
    gap: 0.25rem;
}

.admin-mode .sub-actions {
    display: flex;
}

.btn-sub-action {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1rem;
    opacity: 0.5;
    transition: opacity 0.2s;
}

.btn-sub-action:hover {
    opacity: 1;
    color: var(--primary-color);
}

.btn-sub-action.delete:hover {
    color: #ef4444;
}

/* Subcategory Add Button */
.sub-add-btn {
    display: none;
    margin-top: 2rem;
    padding: 0.5rem 1rem;
    border: 1px dashed var(--border-color);
    background: var(--bg-card);
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: 0.875rem;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    width: 100%;
}

.admin-mode .sub-add-btn {
    display: flex;
}

.sub-add-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}