header {
    display: block;
    unicode-bidi: isolate;
}
body {
    margin: 40px auto;
    max-width: 650px;
    line-height: 1.6;
    font-size: 18px;
    color: #444;
    padding: 0 10px
}

h1,h2,h3 {
    line-height: 1.2
}