html,
body {
  margin: 0;
  padding: 0;
  background: black;
}

:root {
  --white: #ffffff;
  --red: #bc022c;
  --flag-height: 200px;
}

body {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* Start styling */
.flag {
  width: calc(var(--flag-height) * 3 / 2);
  height: var(--flag-height);
  background-color: var(--white);
  display: flex;
  justify-content: center;
  align-items: center;
}

.circle {
  width: calc(var(--flag-height) * 3 / 5);
  height: calc(var(--flag-height) * 3 / 5);
  background-color: var(--red);
  border-radius: 50%;
}