body {
    font-family: sans-serif;
    margin: 0;
    padding: 0;
    background: #f9f9f9;
    color: #333;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 1em;
}

header {
    background: #c3d9e3;
    padding: 2em;
    text-align: center;
}

main {
    padding: 2em 1em;
}

h2 {
    color: #4a7b8c;
}

.line-button {
    display: inline-block;
    padding: 10px 20px;
    background-color: #00c300;
    color: white;
    text-decoration: none;
    border-radius: 5px;
}

footer {
    text-align: center;
    padding: 1em;
    background: #eee;
    margin-top: 2em;
}