:root { color-scheme: light; color: #202124; background: #fff; font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif; }
* { box-sizing: border-box; }
body { margin: 0; }
main { max-width: 75ch; margin-inline: auto; padding: 24px 16px; }
h1 { margin: 0 0 20px; font-size: 24px; line-height: 1.4; }
p { font-size: 16px; line-height: 1.8; }
button { min-height: 44px; padding: 10px 20px; color: #202124; background: #fff; border: 1px solid #777; border-radius: 6px; font: inherit; cursor: pointer; }
button:hover { background: #f5f5f5; }
button:focus-visible { outline: 2px solid #a53621; outline-offset: 3px; }
iframe { display: block; width: 100%; min-height: 400px; height: calc(100dvh - 120px); border: 0; }
[hidden] { display: none; }
::selection { background: #ffe4da; color: #202124; }