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

body {
    font-family: 'Microsoft YaHei', Arial, sans-serif;
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.6;
}

.container {
    display: flex;
    min-height: 100vh;
}

/* 左侧导航栏 */
.sidebar {
    width: 250px;
    background: white;
    box-shadow: 2px 0 10px rgba(0,0,0,0.08);
    padding: 20px;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
}

.sidebar h2 {
    color: #333;
    margin-bottom: 20px;
    font-size: 1.2rem;
}

.nav-list {
    list-style: none;
}

.nav-list li {
    margin-bottom: 10px;
}

.nav-list a {
    display: block;
    padding: 10px 15px;
    color: #666;
    text-decoration: none;
    border-radius: 5px;
    transition: all 0.3s ease;
}

.nav-list a:hover {
    background: #f0f0f0;
    color: #667eea;
}

/* 主内容区 */
.main-content {
    flex: 1;
    margin-left: 250px;
    padding: 20px;
    display: flex;
    flex-direction: column;
}

header {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 700;
}

p.subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* 搜索栏 */
.search-box {
    margin-bottom: 30px;
    text-align: center;
}

.search-input {
    width: 60%;
    padding: 12px 20px;
    border: 1px solid #ddd;
    border-radius: 25px;
    font-size: 1rem;
    outline: none;
    transition: all 0.3s ease;
}

.search-input:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 2px rgba(102, 126, 234, 0.2);
}

.tools-grid {
    flex: 1;
    overflow: auto;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 15px;
    margin-bottom: 30px;
}

.tool-card {
    background: white;
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    text-align: center;
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.12);
}

.tool-icon {
    width: 50px;
    height: 50px;
    margin: 0 auto 15px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 20px;
}

.tool-card h3 {
    margin-bottom: 8px;
    font-size: 1rem;
    color: #333;
}

.tool-card p {
    color: #666;
    margin-bottom: 15px;
    font-size: 0.8rem;
    line-height: 1.4;
}

.tool-card a {
    display: inline-block;
    padding: 8px 16px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-decoration: none;
    border-radius: 20px;
    transition: all 0.3s ease;
    font-size: 0.8rem;
}

.tool-card a:hover {
    background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
    transform: scale(1.05);
}

footer {
    text-align: center;
    padding: 20px;
    background: #333;
    color: white;
    border-radius: 10px;
}

@media (max-width: 768px) {
    .container {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
        box-shadow: 0 2px 10px rgba(0,0,0,0.08);
    }
    
    .main-content {
        margin-left: 0;
    }
    
    header {
        padding: 30px 0;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
    }
    
    .search-input {
        width: 90%;
    }
}