/* ==========================================
   CSS变量定义 - 支持浅色/深色主题
   ========================================== */
:root {
    /* 浅色主题 */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-card: #ffffff;
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --text-muted: #999999;
    --border-color: #e0e0e0;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);

    /* 品牌色 */
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: #818cf8;
    --gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);

    /* 功能色 */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --info: #3b82f6;

    /* 其他 */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 深色主题 */
[data-theme="dark"] {
    --bg-primary: #0f0f0f;
    --bg-secondary: #1a1a1a;
    --bg-card: #1e1e1e;
    --text-primary: #ffffff;
    --text-secondary: #b3b3b3;
    --text-muted: #737373;
    --border-color: #2d2d2d;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
}

/* ==========================================
   全局样式
   ========================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica', 'Arial', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: var(--transition);
    overflow-x: hidden;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ==========================================
   顶部导航栏
   ========================================== */
.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 0;
}

.logo h1 {
    font-size: 24px;
    font-weight: 700;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 4px;
}

.tagline {
    font-size: 12px;
    color: var(--text-secondary);
}

.theme-toggle {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    background: var(--bg-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    transition: var(--transition);
}

.theme-toggle:hover {
    transform: scale(1.05);
    border-color: var(--primary);
}

/* ==========================================
   英雄区域
   ========================================== */
.hero {
    background: var(--bg-secondary);
    padding: 80px 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--gradient);
    opacity: 0.03;
    z-index: 0;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 48px;
    font-weight: 800;
    margin-bottom: 16px;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 20px;
    color: var(--text-secondary);
    margin-bottom: 40px;
}

/* 搜索框 */
.search-box {
    position: relative;
    max-width: 600px;
    margin: 0 auto 48px;
}

.search-input {
    width: 100%;
    padding: 16px 56px 16px 24px;
    font-size: 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    background: var(--bg-card);
    color: var(--text-primary);
    transition: var(--transition);
    outline: none;
}

.search-input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.1);
}

.search-button {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    width: 40px;
    height: 40px;
    border: none;
    border-radius: var(--radius-md);
    background: var(--primary);
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

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

/* 统计信息 */
.stats {
    display: flex;
    justify-content: center;
    gap: 48px;
    flex-wrap: wrap;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.stat-number {
    font-size: 32px;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 4px;
}

.stat-label {
    font-size: 14px;
    color: var(--text-secondary);
}

/* ==========================================
   分类筛选
   ========================================== */
.filters {
    padding: 32px 0;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 73px;
    z-index: 999;
    backdrop-filter: blur(10px);
}

.filter-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.filter-tab {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    background: var(--bg-card);
    color: var(--text-primary);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    white-space: nowrap;
    transition: var(--transition);
}

.filter-tab:hover {
    border-color: var(--primary-light);
    transform: translateY(-2px);
}

.filter-tab.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.tab-icon {
    font-size: 18px;
}

/* ==========================================
   工具卡片网格
   ========================================== */
.main {
    padding: 48px 0;
    min-height: 60vh;
}

.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
    margin-bottom: 48px;
}

.tool-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 24px;
    transition: var(--transition);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient);
    transform: scaleX(0);
    transition: var(--transition);
}

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

.tool-card:hover::before {
    transform: scaleX(1);
}

.tool-header {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 16px;
}

.tool-icon {
    font-size: 40px;
    flex-shrink: 0;
}

.tool-info {
    flex: 1;
}

.tool-name {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--text-primary);
}

.tool-category {
    display: inline-block;
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    font-size: 12px;
    font-weight: 500;
}

.tool-description {
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.6;
    margin-bottom: 16px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.tool-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 16px;
}

.tool-tag {
    padding: 4px 10px;
    border-radius: var(--radius-sm);
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary);
    font-size: 12px;
}

.tool-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--primary);
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    transition: var(--transition);
}

.tool-link:hover {
    color: var(--primary-hover);
    gap: 12px;
}

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 80px 24px;
}

.empty-icon {
    font-size: 64px;
    margin-bottom: 16px;
}

.empty-state h3 {
    font-size: 24px;
    margin-bottom: 8px;
}

.empty-state p {
    color: var(--text-secondary);
}

/* 加载更多 */
.load-more-container {
    text-align: center;
    padding: 24px 0;
}

.load-more-btn {
    padding: 14px 32px;
    border: 2px solid var(--primary);
    border-radius: var(--radius-lg);
    background: transparent;
    color: var(--primary);
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.load-more-btn:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.load-more-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

/* ==========================================
   页脚
   ========================================== */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 48px 0 24px;
    margin-top: 80px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 32px;
}

.footer-section h3 {
    font-size: 18px;
    margin-bottom: 16px;
}

.footer-section p {
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.6;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 8px;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid var(--border-color);
}

.footer-bottom p {
    color: var(--text-muted);
    font-size: 14px;
}

/* ==========================================
   响应式设计
   ========================================== */
@media (max-width: 768px) {
    .hero-title {
        font-size: 32px;
    }

    .hero-subtitle {
        font-size: 16px;
    }

    .stats {
        gap: 32px;
    }

    .stat-number {
        font-size: 24px;
    }

    .tools-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .filter-tabs {
        gap: 8px;
    }

    .filter-tab {
        padding: 10px 16px;
        font-size: 13px;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .hero {
        padding: 48px 0;
    }

    .hero-title {
        font-size: 28px;
    }

    .search-input {
        padding: 14px 50px 14px 20px;
        font-size: 14px;
    }
}

/* ==========================================
   动画效果
   ========================================== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.tool-card {
    animation: fadeIn 0.5s ease-out;
}

/* 平滑滚动 */
html {
    scroll-behavior: smooth;
}

/* 选择文本样式 */
::selection {
    background: var(--primary-light);
    color: white;
}

/* 加载状态 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid var(--border-color);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}