:root {
    color-scheme: light;
    font-family: Arial, "Microsoft YaHei", sans-serif;
    background: white;
    color: black;
}

body {
    width: min(100% - 32px, 980px);
    margin: 0 auto;
    padding: 28px 0 64px;
    overflow-wrap: anywhere;
    line-height: 1.75;
}

h1 {
    margin-top: 0;
}

button {
    margin: 8px;
    font: inherit;
}

hr {
    margin: 22px 0;
    border: 0;
    border-top: 1px solid #d8d8d8;
}

img {
    display: inline-block;
    vertical-align: middle;
}

@media (max-width: 640px) {
    body {
        width: min(100% - 24px, 980px);
        padding-top: 20px;
        font-size: 15px;
    }
}