:root { color-scheme: light dark; font-family: system-ui,sans-serif; }
body { margin: 0; background: light-dark(#f5f7fa,#101720); color: light-dark(#172231,#e3edf5); }
main { max-width: 48rem; margin: 8vh auto; padding: 1.5rem; }
.brand { letter-spacing: .15em; font-weight: 700; }
h1 { font-size: clamp(2rem,6vw,3rem); }
section { border: 1px solid #708090; border-radius: 1rem; padding: 1rem 1.5rem; margin: 1rem 0; }
p { line-height: 1.6; }
button { font: inherit; border-radius: .6rem; padding: .7rem 1rem; cursor: pointer; }