* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; display: grid; place-items: center; background: #f3f4f6; font-family: system-ui, 'Malgun Gothic', sans-serif; color: #111827; }
main { width: 320px; padding: 32px; background: #fff; border-radius: 8px; box-shadow: 0 1px 6px rgba(0, 0, 0, .12); }
h1 { margin: 0 0 24px; font-size: 20px; text-align: center; }
label { display: block; margin-bottom: 14px; font-size: 13px; color: #374151; }
input { display: block; width: 100%; margin-top: 4px; padding: 9px 10px; font-size: 14px; border: 1px solid #d1d5db; border-radius: 4px; }
button { width: 100%; padding: 10px; font-size: 14px; color: #fff; background: #1f2937; border: 0; border-radius: 4px; cursor: pointer; }
button:disabled { opacity: .6; cursor: default; }
#error { margin: 0 0 12px; font-size: 13px; color: #b91c1c; }