body {
    background-color: lightgrey;
    text-align:center;
}

h1, h2, h3, h4, h5, h6 {
    font-family: "Segoe UI", Candara, "Bitstream Vera Sans", "DejaVu Sans", "Bitstream Vera Sans", "Trebuchet MS", Verdana, "Verdana Ref", sans-serif;
    margin:0;
    padding:0;
}

header {
    margin: 2em;
}

input[type=number] {
    width: 3em;
}

body, a, input {
    color: #1e1e1e;
    font-family: Constantia, "Lucida Bright", Lucidabright, "Lucida Serif", Lucida, "DejaVu Serif", "Bitstream Vera Serif", "Liberation Serif", Georgia, serif;
}

.button, #res {
    border: 1px solid #1e1e1e;
    background-color: darkgrey;
    padding: 0.5em;
    border-radius: 0.25em;
}

#res {
    margin: 1em;
    padding: 1em;
    text-align: left;
}