html,
body {
  height: 100%;
}

body {
  display: flex;
  align-items: center;
  padding-top: 40px;
  padding-bottom: 40px;
  background-color: #f5f5f5;
}

.mainpage {
  width: 100%;
  max-width: 400px;
  padding: 	15px;
  margin: auto;
}

.img-flag {
	width: 24px;
	height: 24px;
}

@media ( min-width : 768px) {
	.bd-placeholder-img-lg {
		font-size: 3.5rem;
	}
}