.button {
  background-color: #4CAF50; /* Green */
  border: none;
  color: white;
  padding: 15px 32px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 16px;
  margin: 4px 2px;
  cursor: pointer;
}

.button2 {background-color: #008CBA;} /* Blue */
.button3 {background-color: #f44336;} /* Red */
.button4 {background-color: #e7e7e7; color: black;} /* Gray */
.button5 {background-color: #555555;} /* Black */

.button1 {border-radius: 2px;}
.button2 {border-radius: 4px;}
.button3 {border-radius: 8px;}
.button4 {border-radius: 12px;}
.button5 {border-radius: 50%;}