CSS — flex center

:root {
  color-scheme: light dark;
  font-family: system-ui, sans-serif;
}

body {
  min-height: 100vh;
  margin: 0;
  display: grid;
  place-items: center;
  background: #f4f6f8;
}

.card {
  padding: 1.25rem 1.5rem;
  border-radius: 12px;
  background: #fff;
  box-shadow: 0 8px 24px rgb(15 20 28 / 12%);
}