body {
    background: #3d3d3d;
    color: #f2f2f2;
    font-family: -apple-system, BlinkMacSystemFont , "Helvetica Neue",
        "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC",
        "WenQuanYi Micro Hei", sans-serif;
    font-weight: 300;
    font-size: 15px;
}

header {
    width: 90%;
    max-width: 1240px;
    margin: 0 auto;
    position: relative;
    padding: 20px 30px;
    text-align: center;
    font-size: 20px;
}

header h1 {
    font-size: 34px;
    margin: 0 auto;
    font-weight: 700;
}

header span {
    display: block;
    font-weight: 300;
    text-align: left;
    padding-bottom: 0.5em;
}

a {
    color: #f2f2f2;
}

.main {
    max-width: 1800px;
    margin: auto;
}

footer {
    text-align: center;
    padding: 0.5em;
}

footer > p.credits {
    font-size: 0.6em;
    font-style: bold;
    padding-top: 0.4em;
    opacity: 0.6;
}