<<'EOF'
* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body {
  display: flex; align-items: center; justify-content: center;
  padding: 24px;
  background: #f2f5f9;
  font-family: "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: #1f2a37;
}
.card {
  max-width: 560px; width: 100%;
  background: #fff; border-radius: 12px;
  padding: 40px 32px; text-align: center;
  box-shadow: 0 6px 24px rgba(31, 58, 95, .12);
  border-top: 6px solid #1f3a5f;
}
.icon { font-size: 44px; margin-bottom: 8px; }
h1 { margin: 0 0 16px; font-size: 26px; color: #1f3a5f; }
p  { margin: 0 0 12px; font-size: 17px; line-height: 1.6; color: #4b5563; }
@media (prefers-color-scheme: dark) {
  body { background: #111827; color: #e5e7eb; }
  .card { background: #1f2937; box-shadow: none; }
  h1 { color: #93c5fd; }
  p  { color: #d1d5db; }
}
EOF