adding a "width" to a class overrides "display: flex" "align-items: center" & "justify-content: center" and aligns it to the left corner [duplicate]

I just want the box created to be centered on the bottom of the page and wide ~410px.
but every time I add "width" regardless of what follows "px/%" the box starts aligning to the left side of the page.

.disclamer { display: flex; justify-content: center; margin-top: 10px; border: 1px solid #000; background-color: #B54343; align-items: center; width: 410px; } <div class="disclamer"> <a>TEXTTEXTTEXTTEXT </a> </div>

I'm sure it's something simple, but I'm new and cannot find anyone discussing an issue like that. So I'm just lost. All other <div> are closed.