如何使用css固定相同的div高度

Question

我面临的div高度不一样的问题

以下是此div的代码，其中div的高度不同

<?php for($i=0; $i<4; $i++) { ?>
<div class="col-md-3">
    <div class="card card-stats card-raised">
        <div class="card-body">
          <div class="row"> 
            <div class="col-sm-12">
                <a href="<?php echo $Row_DS['wizardpage'];?>?ds_pid=<?php echo $catid1 = Encrypt($Row_DS['id']);?>" style="color: #fff !important;" class="category_link"><button class="btn btn-primary btn-block">Add <?php echo $Row_DS['prefix'];?></button></a> 
            </div>
    <?php if($Row_DS['id'] == '13'){
          $prospectiveID = 14;
          $prospectName = "Add Prospective Clients";
          $fileName = "client"; 
   } elseif($Row_DS['id'] == '15'){
          $prospectiveID = 16;
          $prospectName = "Add Prospective Donors";
          $fileName = "donor";
   } elseif($Row_DS['id'] == '17'){
          $prospectiveID = 18;
          $prospectName = "Add Prospective Beneficiaries";
          $fileName = "beneficary";
   } elseif($Row_DS['id'] == '19'){
          $prospectiveID = 20;
          $prospectName = "Add Prospective Employees";
          $fileName = "employee";
   } elseif($Row_DS['id'] == '21'){
          $prospectiveID = 22;
          $prospectName = "Add Prospective Contractors";
          $fileName = "contractor";
   } elseif($Row_DS['id'] == '23'){
          $prospectiveID = "23";
          $prospectName = "";
          $fileName = "volunteer";
   } elseif($Row_DS['id'] == '24'){
          $prospectiveID = "24";
          $fileName = "supplier";
          $prospectName = "";
   } elseif($Row_DS['id'] == '25'){
          $prospectiveID = "25";
          $prospectName = "";
          $fileName = "minor";
   } else {
        $prospectiveID = "";
    }     ?>   

   <div class="col-sm-12" <?php if($prospectName == ""){?> style="display:none;" <?php } else{?> style="display:block;"<?php } ?>>

   <a href="<?php echo $Row_DS['wizardpage'];?>?ds_pid=<?php echo $catid1 = Encrypt($prospectiveID);?>" style="color: #fff !important;" class="category_link"><button class="btn btn-primary btn-block"><?php echo $prospectName;?></button></a>
                    </div>
     <div class="col-sm-12" align="center">
        <label>
            OR
        </label>
     </div>   
        <div class="col-sm-12" align="center">
                            <label>
                                Upload Record via Excel (.xls) Format <a href="../../uploads/samples/<?php echo $fileName;?>_sample_file_04072018.xls">Download Sample</a>
                            </label>
                            <div class="fileinput fileinput-new text-center" data-provides="fileinput">

                                    <div class="fileinput-preview fileinput-exists thumbnail"></div>
                            <form id="TypeValidation<?php echo $i1;?>" method="" enctype="multipart/form-data">
                        <input type="hidden" id="pii_categoryid" name="pii_categoryid" value="<?php echo $Row_DS['id'];?>" /> 
                                    <div>
                                        <span class="btn btn-rose btn-round btn-file">
                                            <span class="fileinput-new">Select File</span>
                                            <span class="fileinput-exists">Change</span>
                                            <input type="file" name="<?php echo $fileName;?>_attachment" id="<?php echo $fileName;?>_attachment" accept=".xlsx, .xls, .csv" />
                                        </span>
                                        <a href="#" class="btn btn-danger btn-round fileinput-exists" data-dismiss="fileinput"><i class="fa fa-times"></i> Remove</a>
                                        <button type="submit" name="add_file" id="add_file" value="<?php echo $fileName;?>_file" class="btn btn-success btn-round fileinput-exists">Upload</button>
                                    </div>
                                    </form>
                            </div>
                    </div> 
          </div>  
        </div>
    </div>
</div>
<?php } ?>

我已经尝试使用CSS属性max-height和min-height来尝试它，但是仍然无法正常工作。如何解决这个错误？ b可以使用显示属性或除CSS中的属性添加以外的其他属性来解决此问题吗？