/* CSS变量定义 - 根据设计规范 */
:root {
    /* 主色调 */
    --primary-color: #5B6AFF;
    --secondary-color: #8C54FF;
    --accent-color: #667EEA;
    
    /* 背景色 */
    --bg-primary: #FFFFFF;
    --bg-secondary: #F5F7FA;
    --bg-card: #FFFFFF;
    
    /* 文字颜色 */
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-muted: #999999;
    
    /* 边框和阴影 */
    --border-color: #E5E7EB;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
    
    /* 间距和圆角 */
    --radius: 12px;
    --spacing-xs: 8px;
    --spacing-sm: 16px;
    --spacing-md: 24px;
    --spacing-lg: 32px;
    
    /* 布局尺寸 */
    --header-height: 60px;
    --sidebar-width: 240px;
    --sidebar-collapsed-width: 60px;
}

/* 暗色主题 */
[data-theme="dark"] {
    --bg-primary: #1F2937;
    --bg-secondary: #111827;
    --bg-card: #374151;
    --text-primary: #F9FAFB;
    --text-secondary: #D1D5DB;
    --text-muted: #9CA3AF;
    --border-color: #4B5563;
}

/* 基础样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-secondary);
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* 顶部导航栏 */
.top-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--spacing-md);
    z-index: 1000;
    backdrop-filter: blur(8px);
    box-shadow: var(--shadow-sm);
}

.nav-left {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.sidebar-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius);
    transition: background-color 0.3s ease;
}

.sidebar-toggle span {
    width: 20px;
    height: 2px;
    background: var(--text-primary);
    transition: all 0.3s ease;
}

.sidebar-toggle:hover {
    background: var(--bg-secondary);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    letter-spacing: -0.025em;
}

.logo-subtitle {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-weight: 500;
}

.nav-center {
    flex: 1;
    max-width: 600px;
    margin: 0 var(--spacing-lg);
}

.search-container {
    position: relative;
    display: flex;
    align-items: center;
}

#searchInput {
    width: 100%;
    padding: var(--spacing-xs) var(--spacing-sm);
    padding-right: 48px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 0.875rem;
    transition: all 0.3s ease;
    outline: none;
}

#searchInput:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(91, 106, 255, 0.1);
}

#searchInput::placeholder {
    color: var(--text-muted);
}

.search-btn {
    position: absolute;
    right: var(--spacing-xs);
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 4px;
    border-radius: 6px;
    transition: all 0.3s ease;
}

.search-btn:hover {
    color: var(--primary-color);
    background: var(--bg-primary);
}

.nav-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.theme-toggle {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius);
    transition: all 0.3s ease;
    position: relative;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background: var(--bg-secondary);
    color: var(--primary-color);
}

.moon-icon {
    display: none;
}

[data-theme="dark"] .sun-icon {
    display: none;
}

[data-theme="dark"] .moon-icon {
    display: block;
}

/* 主容器布局 */
.main-container {
    display: grid;
    grid-template-columns: var(--sidebar-width) 1fr;
    margin-top: var(--header-height);
    min-height: calc(100vh - var(--header-height));
    transition: grid-template-columns 0.3s ease;
}

/* 左侧导航 */
.sidebar {
    background: var(--bg-primary);
    border-right: 1px solid var(--border-color);
    overflow-y: auto;
    position: sticky;
    top: var(--header-height);
    height: calc(100vh - var(--header-height));
    transition: all 0.3s ease;
}

/* 法律链接样式 */
.legal-links {
    margin-top: auto;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
}

.legal-link {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.75rem;
    font-weight: 400;
    transition: color 0.3s ease;
}

.legal-link:hover {
    color: var(--text-secondary);
}

/* 确保sidebar-content使用flex布局 */
.sidebar-content {
    padding: var(--spacing-md);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.category-section,
.alphabet-section {
    margin-bottom: var(--spacing-lg);
}

.category-section h3,
.alphabet-section h3 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-sm);
}

.category-nav {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.category-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius);
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
}

.category-item:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.category-item.active {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
}

.category-icon {
    font-size: 1rem;
}

.category-text {
    flex: 1;
}

.category-count {
    background: var(--bg-secondary);
    color: var(--text-muted);
    font-size: 0.75rem;
    padding: 2px 6px;
    border-radius: 10px;
    min-width: 20px;
    text-align: center;
}

.category-item.active .category-count {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.alphabet-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 4px;
}

.alphabet-btn {
    width: 32px;
    height: 32px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-secondary);
    font-size: 0.75rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.alphabet-btn:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: scale(1.05);
}

/* 主内容区 */
.main-content {
    padding: var(--spacing-lg);
    overflow-y: auto;
}

.content-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-lg);
}

.content-header h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.025em;
}

.view-controls {
    display: flex;
    gap: 4px;
    background: var(--bg-secondary);
    padding: 4px;
    border-radius: var(--radius);
}

.view-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: 8px;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.view-btn.active {
    background: var(--bg-primary);
    color: var(--primary-color);
    box-shadow: var(--shadow-sm);
}

/* 词汇容器 */
.terms-container {
    position: relative;
}

.terms-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-md);
    transition: all 0.3s ease;
}

.terms-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

/* 词汇卡片 */
.term-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: var(--spacing-md);
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.term-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    transition: width 0.3s ease;
}

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

.term-card:hover::before {
    width: 8px;
}

.term-card.list-view {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
}

.term-card.list-view:hover {
    transform: translateX(4px);
}

.term-name {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
    letter-spacing: -0.025em;
}

.term-name-en {
    font-size: 0.875rem;
    color: var(--text-muted);
    font-style: italic;
    margin-bottom: var(--spacing-sm);
    font-weight: 400;
}

.term-brief {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.6;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.term-category {
    display: inline-block;
    background: var(--bg-secondary);
    color: var(--text-muted);
    font-size: 0.75rem;
    padding: 4px 8px;
    border-radius: 6px;
    margin-top: var(--spacing-sm);
    font-weight: 500;
}

/* 模态框 */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(8px);
    z-index: 2000;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    background: var(--bg-primary);
    margin: 5% auto;
    padding: var(--spacing-lg);
    border-radius: var(--radius);
    width: 90%;
    max-width: 800px;
    max-height: 80vh;
    overflow-y: auto;
    position: relative;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    animation: slideUp 0.3s ease;
}

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

.modal-close {
    position: absolute;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius);
    transition: all 0.3s ease;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-close:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.term-detail-name {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
    letter-spacing: -0.025em;
}

.term-detail-name-en {
    font-size: 1.25rem;
    color: var(--text-muted);
    font-style: italic;
    margin-bottom: var(--spacing-md);
    font-weight: 400;
}

.term-detail-category {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: var(--spacing-md);
}

.term-detail-description {
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
    font-size: 1rem;
}

.term-detail-example {
    background: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: var(--radius);
    border-left: 4px solid var(--primary-color);
    margin-top: var(--spacing-md);
    position: relative;
}

.term-detail-example::before {
    content: '💡';
    position: absolute;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    font-size: 1.25rem;
}

/* 加载状态 */
.loading-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
    color: var(--text-muted);
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-color);
    border-top: 3px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: var(--spacing-sm);
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 移动端遮罩 */
.mobile-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .sidebar-toggle {
        display: flex;
    }
    
    .main-container {
        grid-template-columns: 1fr;
    }
    
    .sidebar {
        position: fixed;
        top: var(--header-height);
        left: -100%;
        width: var(--sidebar-width);
        z-index: 1001;
        transition: left 0.3s ease;
    }
    
    .sidebar.open {
        left: 0;
    }
    
    .mobile-overlay.show {
        display: block;
    }
    
    .nav-center {
        margin: 0 var(--spacing-sm);
    }
    
    .terms-grid {
        grid-template-columns: 1fr;
    }
    
    .content-header {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }
    
    .modal-content {
        width: 95%;
        margin: 10% auto;
        padding: var(--spacing-md);
    }
    
    .term-detail-name {
        font-size: 2rem;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .terms-grid {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    }
}

@media (min-width: 1025px) {
    .terms-grid {
        grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    }
}

/* 可访问性 */
*:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* 滚动条美化 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* 动画优化 */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}