Learn CSS3 to style your web pages

.button {
    background-color: #336699; /* blue */
    border: none;
    color: white;
    padding: 15px 32px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
}

.button1 {background-color: #008CBA;font-size: 10px;} /* Blue */
.button2 {background-color: #f44336;font-size: 12px;} /* Red */
.button3 {background-color: #e7e7e7; color: black;font-size: 16px;} /* Gray */
.button4 {background-color: #555555;font-size: 24px;} /* Black */

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