body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
}

header {
    background-color: #2d3e50;
    color: white;
    padding: 1rem;
    text-align: center;
}

nav ul {
    list-style: none;
    padding: 0;
}

nav ul li {
    display: inline;
    margin-right: 20px;
}

section#tools {
    padding: 2rem;
    text-align: center;
}

.tool {
    background-color: #fff;
    border: 1px solid #ccc;
    padding: 1rem;
    margin-bottom: 1rem;
}