.container{
    max-width: 600px;
}

body{
    
    background-image: url(../images/num2.jpg);
}
.button1 {background-color: #4CAF50; border-radius: 12px;} /* Green */
.button2 {background-color: #008CBA;border-radius: 12px;} /* Blue */
.button3 {background-color: #f44336;border-radius: 12px;} /* Red */
.button4 {background-color: #e7e7e7; color: black; border-radius: 12px;} /* Gray */
.button5 {background-color: #555555; border-radius: 12px;} /* Black */