input.invalid {
    background-color: #ffdddd
}

.tab {
    display: none
}

#regForm button {
    background-color: #4CAF50;
    color: #ffffff;
    border: none;
    padding: 10px 20px;
    font-size: 17px;
    cursor: pointer
}

button:hover {
    opacity: 0.8
}

#prevBtn {
    background-color: #bbbbbb
}

.step {
    height: 15px;
    width: 15px;
    margin: 0 2px;
    background-color: #bbbbbb;
    border: none;
    border-radius: 50%;
    display: inline-block;
    opacity: 0.5
}

.step.active {
    opacity: 1
}

.step.finish {
    background-color: #4CAF50
}

.all-steps {
    text-align: center;
    margin-top: 30px;
    margin-bottom: 30px
}

.thanks-message {
    display: none
}

/* Hide the browser's default radio button */

.container input[type="radio"] {
    position: absolute;
    opacity: 0;
    cursor: pointer;
}


/* Create a custom radio button */

.checkmark {
    position: absolute;
    top: 0;
    left: 0;
    height: 25px;
    width: 25px;
    background-color: #eee;
    border-radius: 50%;
}


/* On mouse-over, add a grey background color */

.container:hover input~.checkmark {
    background-color: #ccc;
}


/* When the radio button is checked, add a blue background */

.container input:checked~.checkmark {
    background-color: #2196F3;
}


/* Create the indicator (the dot/circle - hidden when not checked) */

.checkmark:after {
    content: "";
    position: absolute;
    display: none;
}


/* Show the indicator (dot/circle) when checked */

.container input:checked~.checkmark:after {
    display: block;
}


/* Style the indicator (dot/circle) */

.container .checkmark:after {
    top: 9px;
    left: 9px;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: white;
}