* { box-sizing: border-box; }
:root {
  font-family: "Segoe UI", Arial, sans-serif;
  color: #242424;
  background: #f5f5f5;
}
body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}
.card {
  width: min(100%, 520px);
  padding: 40px 32px;
  text-align: center;
  background: #ffffff;
  border: 1px solid #e1e1e1;
  border-radius: 16px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, .08);
}
.logo {
  width: 72px;
  height: 72px;
  margin: 0 auto 20px;
  display: grid;
  place-items: center;
  border-radius: 18px;
  color: #ffffff;
  background: #5b5fc7;
  font-size: 36px;
  font-weight: 700;
}
h1 { margin: 0 0 12px; font-size: 30px; }
p { margin: 0 0 28px; color: #616161; line-height: 1.5; }
.button {
  display: inline-block;
  min-width: 220px;
  padding: 13px 24px;
  border-radius: 8px;
  color: #ffffff;
  background: #5b5fc7;
  text-decoration: none;
  font-weight: 600;
}
.button:hover { background: #4f52b2; }
.button:focus-visible { outline: 3px solid #8b8cc7; outline-offset: 3px; }
.help { margin: 20px 0 0; font-size: 13px; }
@media (prefers-color-scheme: dark) {
  :root { color: #ffffff; background: #202020; }
  .card { background: #292929; border-color: #444444; }
  p { color: #d0d0d0; }
}