body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: #102030;
  color: #f4f7fb;
  min-height: 100vh;
  display: grid;
  place-items: center;
}
.card {
  width: min(760px, calc(100vw - 40px));
  background: #182c42;
  border: 1px solid #2e5278;
  border-radius: 18px;
  padding: 28px;
  box-shadow: 0 16px 40px rgba(0,0,0,.35);
}
.logo { width: 84px; height: 84px; }
button {
  background: #3ca8ff;
  color: #001d33;
  border: 0;
  padding: 12px 18px;
  border-radius: 10px;
  cursor: pointer;
  font-weight: bold;
}
pre {
  background: #081522;
  border-radius: 10px;
  padding: 16px;
  overflow: auto;
}
.small { color: #b8cfdf; font-size: .9rem; }