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

.container {
    width: 90%;
    max-width: 700px;
    margin: 0 auto;
}

header {
    margin-bottom: 3em;
}

#main {
    margin-bottom: 3em;
}

h1 {
    font-size: 1.7em;
    margin: 0;
}

h2 {
    font-size: 1.5em;
    margin-bottom: 1em;
    text-align: left;
}