body { font: 16px/1.5 system-ui, sans-serif; margin: 2rem auto; max-width: 42rem; padding: 0 1rem; }
h1 { font-size: 1.5rem; }
h2 { font-size: 1.1rem; margin-top: 2rem; }
ul { list-style: none; padding: 0; }
li { border: 1px solid #ddd; border-radius: 6px; padding: .75rem; margin-bottom: .5rem; }
button { font: inherit; padding: .4rem .8rem; cursor: pointer; }
input { font: inherit; padding: .4rem; display: block; margin: .25rem 0 .75rem; width: 100%; }
code { background: #f3f3f3; padding: .2rem .4rem; }
.last-error { color: #a00; margin: .5rem 0 0; }
#error { color: #a00; }