<div id="contentContainerModule">
        <div class="row">
            <div class="col-lg-7" id="userProfileOverview">
               // some more thml
             </div>
        <div class="row">
            <div class="col-lg-7" id="furtherInfosProfile">
                <div class="form-group">
                    <label class="control-label">
                        label
                    </label>
                    <div class="form-control-plaintext">
                        personnelNmbr
                    </div>
                </div>
                <div class="form-group">
                    // other info
                </div>
            </div>
        </div>
        <div class="row">
            <div class="col-lg-7" id="changePassword">
                <div class="form-group">
                    <label class="control-label">
                       username
                    </label>
                   // other div
                </div>
            </div>
        <div class="row">
            <div class="col-lg-7" id="languageSettings">
                <div class="form-group">
                   // something
                </div>
            </div>
        </div>
        <hr>
    <div class="text-center">
        <button type="submit" class="btn btn-success" id="saveButtonProfile">save</button>
    </div>
</div>
<div id="darkness"></div>

darkness {
  position: absolute;
  z-index: 1;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, .5);
}