body { margin: 0; font: 16px/1.5 system-ui, sans-serif; color: #16233a; background: #f5f7fb; }
main { max-width: 42rem; margin: 12vh auto; padding: 2rem; background: #fff; border: 1px solid #d8dee8; border-radius: .5rem; }
button { padding: .6rem 1rem; font: inherit; cursor: pointer; }