How to show/hide an element in real time (Blazor)?

The hidden html attribute also works to hide an element.

<p hidden>This paragraph should be hidden.</p>

To bind to Model:

 <p hidden="@HideLabel">I am Hidden When HideLabel == true</p>

 <p hidden="@(!HideLabel)">I am Hidden when Hidelabel == false</p>
    
 <button @onclick="@Toggle">Show/Hide</button>

 @code {
      private bool HideLabel { get; set; } = false;
      private void Toggle()
      {
         HideLabel =   !HideLabel;
      }      
 } 

Edit: You can also use a CSS class to hide/show an element:

<div class="font-italic @(HideLabel ? "d-none" : "d-show")">
   I am Hidden When HideLabel == true
</div>