.errorInput {
    color: red;
}
.errorInput:focus {
    color: inherit;
}
.errorInput:focus + .errorTextForm {
    display: none;
}

div.errorTextForm {
    background: #dedede;
    border-radius: 8px;
    border: 1px solid #fff;
    color: red;
    line-height: 1.5;
    text-align: center;
    -moz-border-radius: 8px;
    -webkit-border-radius: 8px;
    padding: 5px 10px;
    position: absolute;
    width: auto;
    z-index: 1;
    font-family: sans-serif;
    font-size: 14px;
    top: calc(50% + 5px);
}

div.errorTextForm:after{
    border: 10px solid;
    border-color: transparent transparent #dedede transparent;
    bottom: 100%;
    content: '';
    height: 0;
    left: 50%;
    margin-left: -10px;
    position: absolute;
    width: 0;
}

button:disabled {
    background: #b3b3b3 !important;
    cursor: not-allowed;
}