body {
    background-color: #f8f9fa;
    font-family: 'Microsoft YaHei', sans-serif;
}

.tool-card {
    transition: transform 0.3s, box-shadow 0.3s;
    border-radius: 10px;
    overflow: hidden;
    border: none;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
}

.tool-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: #0d6efd;
}

.btn-primary {
    border-radius: 20px;
    padding: 0.5rem 1.5rem;
}

header {
    position: relative;
}

header::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 3px;
    background-color: #0d6efd;
    border-radius: 3px;
}