CSS Fill With Yellow Button Animation


.button {
  background-color: #4CAF50; 
  font-size: 13px;
  -webkit-transition-duration: 0.3s;
  transition-duration: 0.2s;
  padding: 38px;
  -webkit-transition-duration: 0.3s;
  transition-duration: 0.3s;
}

.codebutton4 {
    padding-top: 0.3em;
    padding-bottom: 0.3em;
    background-color: #d9d9d9;
    border-top-left-radius: 10px;
    border-bottom-left-radius: 10px;
    border-top-right-radius: 10px;
    border-bottom-right-radius: 10px;
    border: 4px solid #ff9900;

}

.codebutton4:hover {
  background-color: #ff9900;
}

Button Animations CSS (w/ code)