*,
*:before,
*:after {
  box-sizing: border-box;
}

body {
    margin: 0;
    height: 100vh;
    background-color: darkgrey;
    padding: 10px;

}

#svetofor, #padestrianSvetofor, #padestrianSvetoforButton{
  width: 100px;
  height: 100px;
  border-radius: 50%;
  margin: 20px;
  border: 2px solid black;
  display: flex;
  justify-content: center;
  align-items: center;
  color: green;
  font-weight: bolder;
}

.svetoforRed {
  background-color: red;
}

.svetoforYellow {
  background-color: yellow;
}

.svetoforGreen {
  background-color: green;
}