body { font-family: system-ui, sans-serif; max-width: 28rem; margin: 3rem auto; padding: 0 1rem;
  color: #1a1a1a; background: #fff; }
h1 { font-size: 1.4rem; }
label { display: block; margin-top: 1rem; }
input[type=text], input[type=password] { width: 100%; padding: 0.5rem; box-sizing: border-box; }
button { margin-top: 1.25rem; padding: 0.5rem 1.25rem; }
.error { color: #a40000; margin-top: 1rem; }