* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: #02010a;
}

.swiss-flag {
  position: relative;
  width: 500px;
  height: 500px;
  background-color: #ff0000;
}

.cross {
  position: absolute;
  width: 75%;
  height: 20%;
  background-color: #ffffff;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.cross.horizontal {
  width: 20%;
  height: 75%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}