mdb-ui-kit/less/inputs.less

// main: material.less

.form-control-wrapper .form-control, .form-control {
    &, &:focus {
        float: none;
        border: 0;
        box-shadow: none;
        border-radius: 0;
        background: transparent;
        border-bottom: 1px solid #757575;
        &:disabled {
            border-style: dashed;
        }
    }
}

.form-control-wrapper {
    position: relative;

    .form-control:focus {
        outline: none;
    }

    .floating-label {
        color: #7E7E7E;
        font-size: 14px;
        position: absolute;
        pointer-events: none;
        left: 12px;
        top: 7px;
        transition: 0.2s ease all;
        opacity: 0;
    }
    .form-control:focus ~ .floating-label {
        top: -10px;
        font-size: 10px;
        color: @input-default;
    }
    .form-control:not(.empty) ~ .floating-label {
        top: -10px;
        font-size: 10px;
        opacity: 1;
    }
    .form-control:focus:invalid ~ .floating-label {
        color: @input-danger;
    }
    .form-control:focus ~ .material-input:after {
        background-color: @input-default;
    }
    .form-control:focus:invalid ~ .material-input {
        &:before, &:after  {
            background-color: @input-danger;
        }
    }
    .form-control.empty ~ .floating-label {
        opacity: 1;
    }
    .material-input:before {
        position: absolute;
        content: "";
        width: 100%;
        left: 0;
        height: 2px;
        background-color: @input-default;
        bottom: -1px;
        transform: scaleX(0);
        transition: transform 0s;
    }
    .form-control:focus  ~ .material-input:before {
        transform: scaleX(1);
        transition: transform 0.2s ease-out;
    }
    .material-input:after {
        content: "";
        position: absolute;
        height: 18px;
        width: 100px;
        margin-top: -1px;
        top: 25%;
        left: 0;
        pointer-events: none;
        opacity: 0.9;
    }
    .input-lg ~ .material-input:after {
        height: 26px;
    }
    textarea { resize: none; }
    textarea ~ .form-control-highlight {
        margin-top: -11px;
    }

    /* active state */
    .form-control:focus ~ .material-input:after {
        -webkit-animation: input-highlight 0.3s ease;
        animation: input-highlight 0.3s ease;
        -webkit-animation-fill-mode: forwards;
        animation-fill-mode: forwards;
    }

    select ~ .material-input:before {
        bottom: 1px;
    }
    select ~ .material-input:after {
        display: none;
    }

}

.form-group {
    &.has-warning {
        .material-input:before, input.form-control:focus ~ .material-input:after {
            background: @input-warning;
        }
        .control-label, input.form-control:focus ~ .floating-label {
            color: @input-warning;
        }
    }
    &.has-error {
        .material-input:before, input.form-control:focus ~ .material-input:after {
            background: @input-danger;
        }
        .control-label, input.form-control:focus ~ .floating-label {
            color: @input-danger;
        }
    }
    &.has-success {
        .material-input:before, input.form-control:focus ~ .material-input:after {
            background: @input-success;
        }
        .control-label, input.form-control:focus ~ .floating-label {
            color: @input-success;
        }
    }
    &.has-info {
        .material-input:before, input.form-control:focus ~ .material-input:after {
            background: @input-info;
        }
        .control-label, input.form-control:focus ~ .floating-label {
            color: @input-info;
        }
    }
    .variations(~" .material-input:before", background-color, @indigo);
    .variations(~" input.form-control:focus ~ .material-input:after", background-color, @indigo);
    .variations(~" .control-label", color, @lightbg-text);
    .variations(~" input.form-control:focus ~ .floating-label", color, @indigo);

}

.input-group {
    .form-control-wrapper {
        .form-control {
            float: none;
        }
        margin-right: 5px;
        margin-left: 5px;
        bottom: -10px;
    }
    .input-group-addon {
        border: 0;
    }
    .input-group-btn .btn {
        border-radius: 4px;
    }
}

select.form-control {
    border: 0;
    box-shadow: none;
    border-bottom: 1px solid #757575;
    border-radius: 0;
    &:focus {
        box-shadow: none;
        border-color: #757575;
    }
}