/* CSS 变量定义 */
:root {
    --primary-color: #4f46e5;
    --primary-dark: #3730a3;
    --secondary-color: #06b6d4;
    --accent-color: #f59e0b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --bg-dark: #111827;
    
    --border-color: #e5e7eb;
    --border-light: #f3f4f6;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    --font-family: 'Inter', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
}

/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.6;
}

/* 语言切换器 */
.language-switcher {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
}

.lang-btn {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 8px 16px;
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: var(--shadow-md);
    font-size: 14px;
    color: var(--text-primary);
}

.lang-btn:hover {
    background: var(--bg-secondary);
    transform: translateY(-1px);
}

.lang-dropdown {
    position: absolute;
    top: 100%;
    right: 0;
    margin-top: 8px;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.2s ease;
    min-width: 120px;
}

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

.lang-option {
    display: block;
    width: 100%;
    padding: 10px 16px;
    background: none;
    border: none;
    text-align: left;
    cursor: pointer;
    transition: background-color 0.2s ease;
    font-size: 14px;
    color: var(--text-primary);
}

.lang-option:hover {
    background: var(--bg-secondary);
}

.lang-option:first-child {
    border-radius: var(--radius-md) var(--radius-md) 0 0;
}

.lang-option:last-child {
    border-radius: 0 0 var(--radius-md) var(--radius-md);
}

/* 主容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
}

/* 头部区域 */
.header {
    text-align: center;
    margin-bottom: 60px;
}

.logo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    margin-bottom: 20px;
}

.logo-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 36px;
    color: white;
    box-shadow: var(--shadow-lg);
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
}

.header h1 {
    font-size: 3rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
}

.subtitle {
    font-size: 1.25rem;
    color: white;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
}

/* 工具卡片网格 */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-bottom: 80px;
}

.tool-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: 32px;
    box-shadow: var(--shadow-xl);
    transition: all 0.3s ease;
    border: 1px solid var(--border-light);
    position: relative;
    overflow: hidden;
}

.tool-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
}

.tool-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl), 0 25px 50px -12px rgba(0, 0, 0, 0.25);
}

.tool-card.coming-soon {
    opacity: 0.7;
    cursor: not-allowed;
}

.tool-card.coming-soon:hover {
    transform: none;
}

.tool-icon {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    color: white;
    margin-bottom: 24px;
    box-shadow: var(--shadow-md);
}

.tool-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.tool-card p {
    color: var(--text-secondary);
    margin-bottom: 20px;
    line-height: 1.6;
}

.tool-features {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 24px;
}

.feature-tag {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: 4px 12px;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
}

.tool-btn {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border: none;
    border-radius: var(--radius-lg);
    padding: 12px 24px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 8px;
    width: 100%;
    justify-content: center;
}

.tool-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.tool-btn:active {
    transform: translateY(0);
}

.coming-soon-badge {
    position: absolute;
    top: 20px;
    right: 20px;
    background: var(--accent-color);
    color: white;
    padding: 4px 12px;
    border-radius: var(--radius-md);
    font-size: 0.75rem;
    font-weight: 600;
}

/* 功能特性区域 */
.features-section {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: 60px 40px;
    box-shadow: var(--shadow-xl);
    margin-bottom: 60px;
}

.features-section h2 {
    text-align: center;
    font-size: 2.25rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 50px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
}

.feature-item {
    text-align: center;
}

.feature-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    color: white;
    margin: 0 auto 20px;
    box-shadow: var(--shadow-md);
}

.feature-item h4 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.feature-item p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 页脚 */
.footer {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-xl);
    padding: 30px;
    text-align: center;
    margin-top: 40px;
}

.footer-content p {
    color: white;
    opacity: 0.9;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 20px 16px;
    }
    
    .header h1 {
        font-size: 2.5rem;
    }
    
    .subtitle {
        font-size: 1.125rem;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
        gap: 20px;
        margin-bottom: 60px;
    }
    
    .tool-card {
        padding: 24px;
    }
    
    .features-section {
        padding: 40px 20px;
    }
    
    .features-section h2 {
        font-size: 1.875rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .language-switcher {
        top: 16px;
        right: 16px;
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 2rem;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
    }
    
    .tool-card {
        padding: 20px;
    }
    
    .logo-icon {
        width: 60px;
        height: 60px;
        font-size: 28px;
    }
}

/* 加载动画 */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.loading {
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

/* 无障碍支持 */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* 高对比度模式支持 */
@media (prefers-contrast: high) {
    :root {
        --border-color: #000000;
        --text-secondary: #000000;
    }
}