/* ===== CSS变量 ===== */
:root {
    /* 主色调 */
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --primary-light: #60a5fa;
    --primary-bg: #eff6ff;
    
    /* 中性色 */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    /* 功能色 */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    
    /* 背景 */
    --bg-body: #f8fafc;
    --bg-card: #ffffff;
    --bg-hover: #f1f5f9;
    
    /* 阴影 */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    
    /* 圆角 */
    --radius-sm: 6px;
    --radius: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;
    
    /* 过渡 */
    --transition: 0.2s ease;
    --transition-slow: 0.3s ease;
    
    /* 字体 */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-body);
    color: var(--gray-800);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 20px;
}

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

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* ===== 顶部导航 ===== */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-200);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
    gap: 24px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--gray-900);
    transition: transform var(--transition);
}

.logo:hover {
    transform: scale(1.02);
}

.logo-icon {
    font-size: 1.5rem;
}

.logo-text {
    background: linear-gradient(135deg, var(--primary) 0%, #8b5cf6 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* 搜索框 */
.search-box {
    position: relative;
    flex: 1;
    max-width: 480px;
}

.search-icon {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    width: 18px;
    height: 18px;
    color: var(--gray-400);
    pointer-events: none;
}

.search-box input {
    width: 100%;
    height: 42px;
    padding: 0 70px 0 42px;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-full);
    background: var(--gray-50);
    font-size: 0.9375rem;
    color: var(--gray-800);
    transition: all var(--transition);
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary);
    background: var(--bg-card);
    box-shadow: 0 0 0 3px var(--primary-bg);
}

.search-box input::placeholder {
    color: var(--gray-400);
}

.search-shortcut {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    padding: 2px 6px;
    background: var(--gray-100);
    border-radius: 4px;
    font-size: 0.75rem;
    color: var(--gray-500);
    font-family: inherit;
    pointer-events: none;
}

/* ===== Hero区域 ===== */
.hero {
    text-align: center;
    padding: 48px 0 32px;
}

.hero-title {
    font-size: 2.25rem;
    font-weight: 800;
    color: var(--gray-900);
    margin-bottom: 12px;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--gray-500);
}

/* ===== 分类标签 ===== */
.categories {
    margin-bottom: 20px;
}

.category-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.category-tab {
    padding: 8px 16px;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-600);
    background: var(--bg-card);
    border: 1px solid var(--gray-200);
    transition: all var(--transition);
    white-space: nowrap;
}

.category-tab:hover {
    border-color: var(--primary-light);
    color: var(--primary);
    background: var(--primary-bg);
}

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

/* ===== 筛选标签 ===== */
.filters {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 16px;
    margin-bottom: 32px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--gray-200);
}

.filter-group {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
}

.filter-label {
    font-size: 0.875rem;
    color: var(--gray-500);
}

.filter-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    align-items: center;
}

.filter-tag {
    padding: 6px 12px;
    border-radius: var(--radius);
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--gray-600);
    background: var(--bg-card);
    border: 1px solid var(--gray-200);
    transition: all var(--transition);
}

.filter-tag:hover {
    border-color: var(--gray-300);
    background: var(--gray-50);
}

.filter-tag.active {
    background: var(--gray-800);
    color: white;
    border-color: var(--gray-800);
}

.filter-divider {
    width: 1px;
    height: 16px;
    background: var(--gray-200);
    margin: 0 4px;
}

.tool-count {
    font-size: 0.875rem;
    color: var(--gray-500);
}

.tool-count span {
    font-weight: 600;
    color: var(--primary);
}

/* ===== 热门推荐 ===== */
.hot-section {
    margin-bottom: 40px;
}

.section-header {
    margin-bottom: 16px;
}

.section-title {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--gray-900);
}

.hot-icon {
    font-size: 1.25rem;
}

.hot-tools {
    display: flex;
    gap: 16px;
    overflow-x: auto;
    padding-bottom: 8px;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
}

.hot-tools::-webkit-scrollbar {
    height: 6px;
}

.hot-tools::-webkit-scrollbar-track {
    background: var(--gray-100);
    border-radius: 3px;
}

.hot-tools::-webkit-scrollbar-thumb {
    background: var(--gray-300);
    border-radius: 3px;
}

.hot-tools::-webkit-scrollbar-thumb:hover {
    background: var(--gray-400);
}

/* 热门工具卡片 */
.hot-card {
    flex: 0 0 auto;
    width: 200px;
    padding: 16px;
    background: linear-gradient(135deg, #f0f9ff 0%, #faf5ff 100%);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    scroll-snap-align: start;
    transition: all var(--transition);
    cursor: pointer;
}

.hot-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-light);
}

.hot-card-icon {
    width: 40px;
    height: 40px;
    margin-bottom: 12px;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    background: var(--bg-card);
    box-shadow: var(--shadow-sm);
}

.hot-card-name {
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 4px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.hot-card-desc {
    font-size: 0.8125rem;
    color: var(--gray-500);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* ===== 工具网格 ===== */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

/* 工具卡片 */
.tool-card {
    background: var(--bg-card);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    padding: 20px;
    transition: all var(--transition);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary) 0%, #8b5cf6 100%);
    opacity: 0;
    transition: opacity var(--transition);
}

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

.tool-card:hover::before {
    opacity: 1;
}

.tool-card-header {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    margin-bottom: 12px;
}

.tool-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    background: var(--gray-50);
    flex-shrink: 0;
}

.tool-info {
    flex: 1;
    min-width: 0;
}

.tool-name {
    font-size: 1rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 4px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.tool-name-text {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.tool-badge {
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.6875rem;
    font-weight: 500;
    flex-shrink: 0;
}

.badge-free {
    background: #dcfce7;
    color: #16a34a;
}

.badge-freemium {
    background: #fef3c7;
    color: #d97706;
}

.badge-paid {
    background: #ede9fe;
    color: #7c3aed;
}

.tool-category {
    font-size: 0.8125rem;
    color: var(--gray-500);
}

.tool-desc {
    font-size: 0.875rem;
    color: var(--gray-600);
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    margin-bottom: 12px;
}

.tool-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.tool-tag {
    padding: 3px 8px;
    background: var(--gray-100);
    border-radius: 4px;
    font-size: 0.75rem;
    color: var(--gray-600);
}

.tool-tag.china {
    background: #fef2f2;
    color: #dc2626;
}

.tool-tag.global {
    background: #eff6ff;
    color: #2563eb;
}

/* ===== 无结果提示 ===== */
.no-results {
    text-align: center;
    padding: 60px 20px;
}

.no-results-icon {
    font-size: 3rem;
    margin-bottom: 16px;
    opacity: 0.5;
}

.no-results-text {
    font-size: 1.125rem;
    color: var(--gray-700);
    margin-bottom: 8px;
}

.no-results-hint {
    font-size: 0.9375rem;
    color: var(--gray-500);
}

/* ===== 页脚 ===== */
.footer {
    background: var(--bg-card);
    border-top: 1px solid var(--gray-200);
    margin-top: 60px;
    padding: 40px 0;
}

.footer-content {
    text-align: center;
}

.footer-brand {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    font-size: 1.25rem;
    margin-bottom: 12px;
}

.footer-desc {
    font-size: 0.9375rem;
    color: var(--gray-500);
    margin-bottom: 16px;
}

.footer-links {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-bottom: 16px;
}

.footer-links a {
    font-size: 0.875rem;
    color: var(--gray-600);
    transition: color var(--transition);
}

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

.link-divider {
    color: var(--gray-300);
}

.footer-copyright {
    font-size: 0.8125rem;
    color: var(--gray-400);
}

/* ===== 回到顶部 ===== */
.back-to-top {
    position: fixed;
    right: 24px;
    bottom: 24px;
    width: 44px;
    height: 44px;
    border-radius: var(--radius-full);
    background: var(--bg-card);
    border: 1px solid var(--gray-200);
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition);
    z-index: 50;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.back-to-top svg {
    width: 20px;
    height: 20px;
    color: var(--gray-600);
}

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

.tool-card {
    animation: fadeInUp 0.4s ease forwards;
    opacity: 0;
}

.tool-card:nth-child(1) { animation-delay: 0.05s; }
.tool-card:nth-child(2) { animation-delay: 0.1s; }
.tool-card:nth-child(3) { animation-delay: 0.15s; }
.tool-card:nth-child(4) { animation-delay: 0.2s; }
.tool-card:nth-child(5) { animation-delay: 0.25s; }
.tool-card:nth-child(6) { animation-delay: 0.3s; }
.tool-card:nth-child(7) { animation-delay: 0.35s; }
.tool-card:nth-child(8) { animation-delay: 0.4s; }

/* ===== 响应式设计 ===== */
@media (max-width: 768px) {
    .header-content {
        flex-wrap: wrap;
        height: auto;
        padding: 12px 0;
        gap: 12px;
    }
    
    .search-box {
        order: 3;
        flex: none;
        width: 100%;
        max-width: none;
    }
    
    .search-shortcut {
        display: none;
    }
    
    .hero {
        padding: 32px 0 24px;
    }
    
    .hero-title {
        font-size: 1.75rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .category-tabs {
        overflow-x: auto;
        flex-wrap: nowrap;
        padding-bottom: 8px;
        -webkit-overflow-scrolling: touch;
    }
    
    .category-tabs::-webkit-scrollbar {
        display: none;
    }
    
    .filters {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .tool-count {
        width: 100%;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    
    .back-to-top {
        right: 16px;
        bottom: 16px;
        width: 40px;
        height: 40px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    .hero-title {
        font-size: 1.5rem;
    }
    
    .filter-tags {
        gap: 6px;
    }
    
    .filter-tag {
        padding: 5px 10px;
        font-size: 0.75rem;
    }
    
    .hot-card {
        width: 160px;
        padding: 12px;
    }
    
    .tool-card {
        padding: 16px;
    }
    
    .tool-icon {
        width: 42px;
        height: 42px;
        font-size: 1.5rem;
    }
}

/* ===== 语言切换器 ===== */
.header-right {
    display: flex;
    align-items: center;
    gap: 16px;
    flex: 1;
    max-width: 600px;
}

.lang-switcher {
    position: relative;
    flex-shrink: 0;
}

.lang-btn {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 8px 12px;
    background: var(--bg-card);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-700);
    transition: all var(--transition);
}

.lang-btn:hover {
    border-color: var(--gray-300);
    background: var(--gray-50);
}

.lang-arrow {
    width: 14px;
    height: 14px;
    color: var(--gray-400);
    transition: transform var(--transition);
}

.lang-dropdown {
    position: absolute;
    top: calc(100% + 4px);
    right: 0;
    min-width: 100px;
    background: var(--bg-card);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all var(--transition);
    z-index: 200;
    overflow: hidden;
}

.lang-dropdown.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.lang-option {
    display: block;
    width: 100%;
    padding: 10px 14px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-700);
    text-align: center;
    transition: background var(--transition);
}

.lang-option:hover {
    background: var(--gray-50);
}

.lang-option:first-child {
    border-bottom: 1px solid var(--gray-100);
}

/* 响应式更新 */
@media (max-width: 768px) {
    .header-right {
        flex-wrap: wrap;
        width: 100%;
    }
    
    .search-box {
        order: 2;
        flex: none;
        width: 100%;
        max-width: none;
    }
    
    .lang-switcher {
        order: 1;
    }
}