body { margin: 0; min-height: 100vh; display: grid; place-items: center; font: 16px/1.4 system-ui, sans-serif; background: #f7f7f5; color: #1a1a1a; }
main { width: min(92vw, 360px); text-align: center; }
form { display: flex; gap: 8px; }
input { flex: 1; padding: 10px 12px; font-size: 16px; border: 1px solid #bbb; border-radius: 8px; }
button { padding: 10px 16px; font-size: 16px; border: 0; border-radius: 8px; background: #1a1a1a; color: #fff; cursor: pointer; }
#e { color: #b00020; }
@media (prefers-color-scheme: dark) { body { background: #151515; color: #eee; } input { background: #222; color: #eee; border-color: #444; } button { background: #eee; color: #151515; } }
.u { position: absolute; left: -9999px; width: 1px; opacity: 0; }