.powrot {
display: inline-block;
padding: 12px 25px;
border: 1px solid #72C344;;
color: #FFFFFF;;
font-size: 18px;
transition: all 0.5s ease-out 0s;
cursor: pointer;
float: right;
margin: 20px 0px 0px 0px;
background-color: #72C344;;
font-weight: 500;
border-radius: 45px;
}

.powrot:before {
content: '';
display: inline-block;
width: 22px;
height: 15px;
margin-right: 10px;
transition: all 0.5s ease-out 0s;
vertical-align: middle;
background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAwAAAAVCAYAAAByrA+0AAAABHNCSVQICAgIfAhkiAAAAORJREFUOE+Vk0sOgjAURd8rzt2KU2M04GfOEmQHfjbACgw7wH1otCFxrjtwCTi3fVJiCSilpeNz+rn3FcFhbW6rEQp5ZQAR2ngNIyBKD/1OYZ8tQgmQajiZnO5GYZfN14AsBYKX2lnB6jatggluFSoY6CEHIkzG/Fl/Z+OEBvwWfhLw/DeUSnCBqyu5wqXQB/4Ky7zIaljkHSTTM7cViapJJogTEJHHAp23SSwf3UeqUnKVGj24SH+jYZNaZ6lLMk5rXUKg7WF2ORqnVUeqJdUTkIyU5PTjVE+6XKuge0JBMXkYfwCZ9LnpPwux4gAAAABJRU5ErkJggg==');

background-size: auto 100%;
background-repeat: no-repeat;
filter:brightness(0) invert(100%);
}
.powrot:hover:before {
filter:brightness(100%) invert(0);
}

.powrot:hover{
color: #72C344;;
background-color: #FFFFFF;
}

.powrot:hover:before {

}