.callback {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -ms-flex-pack: distribute;
        justify-content: space-around;
    -webkit-box-align: center;
        -ms-flex-align: center;
            align-items: center;
    padding-top: 30px;
    -webkit-box-flex: 1;
        -ms-flex-positive: 1;
            flex-grow: 1;
    height: 100%;
    background: -webkit-gradient(linear, left top, left bottom, from(rgba(221, 179, 45, 1)), color-stop(80%, rgba(221, 179, 45, .8)), to(rgba(221, 179, 45, 1))),
    url("../image/background/workout-zone.webp") center center no-repeat;
    background: -o-linear-gradient(top, rgba(221, 179, 45, 1), rgba(221, 179, 45, .8) 80%, rgba(221, 179, 45, 1)),
    url("../image/background/workout-zone.webp") center center no-repeat;
    background: linear-gradient(to bottom, rgba(221, 179, 45, 1), rgba(221, 179, 45, .8) 80%, rgba(221, 179, 45, 1)),
    url("../image/background/workout-zone.webp") center center no-repeat;
    background-size: cover;
}

.form-container {
    width: 400px;
    height: 300px;
}

.callback-form {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-orient: vertical;
    -webkit-box-direction: normal;
        -ms-flex-direction: column;
            flex-direction: column;
    -webkit-box-pack: center;
        -ms-flex-pack: center;
            justify-content: center;
    -webkit-box-align: center;
        -ms-flex-align: center;
            align-items: center;
}

.input-group {
    padding-top: 22px;
    margin-bottom: -15px;
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-orient: vertical;
    -webkit-box-direction: normal;
        -ms-flex-direction: column;
            flex-direction: column;
    -webkit-box-pack: center;
        -ms-flex-pack: center;
            justify-content: center;
}

.input-group label {
    -webkit-user-select: none;
       -moz-user-select: none;
        -ms-user-select: none;
            user-select: none;
    width: auto;
    position: relative;
    top: -28px;
    left: 10px;
    cursor: text;
    color: #7f7f7f;
    -webkit-transition: all 0.2s ease;
    -o-transition: all 0.2s ease;
    transition: all 0.2s ease;
}

.input-group input:focus + label, .input-group input:valid + label {
    color: #ddb32d;
    top: -55px;
    cursor: default;
}

.input-group input {
    padding-right: 20px;
    outline: none;
    height: 35px;
    width: 300px;
    border: 1px solid #c9c9c9;
    border-bottom: 2px solid #ddb32d;
    -webkit-transition: all 0.3s ease;
    -o-transition: all 0.3s ease;
    transition: all 0.3s ease;

    -webkit-box-sizing: border-box;
    box-sizing: border-box;
}

.input-group input.invalid-input {
    border-bottom: 2px solid red;
}

.input-group input:focus {
    -webkit-box-shadow: 0 2px 1px 0 #ddb32d;
            box-shadow: 0 2px 1px 0 #ddb32d;
}

.input-group input.invalid-input:focus {
    -webkit-box-shadow: 0 2px 1px 0 red;
            box-shadow: 0 2px 1px 0 red;
}

.input-group input:first-child {
    font-weight: bold;
    padding-left: 10px;
    color: #23252b;
}

input[type="button"] {
    -webkit-appearance: none;
       -moz-appearance: none;
            appearance: none;
    outline: none;
    margin: 10px;
    padding: 10px 20px;
    background-color: #ddb32d;
    font-size: 12pt;
    color: #23252b;
    border: none;
    border-radius: 2px;
    cursor: pointer;
}

input[type="button"]:disabled {
    outline: none;
    margin: 10px;
    padding: 10px 20px;
    background-color: #5a5a5a;
    font-size: 12pt;
    color: #23252b;
    border: none;
    border-radius: 2px;
    cursor: pointer;
}

.error-label {
    display: none;
    color: red;
    text-align: center;
    font-size: 11pt;
}

.thank-for-callback-request {
    display: none;
    text-align: center;
    font-size: 11pt;
    color: #23252b;
    padding-top: 10px;
    margin: 5px 10px 0 10px;
}

@media screen and (max-width: 420px) {

    .form-container {
        width: 300px;
    }

    .input-group input {
        width: 150px;
    }
}