댓글쓰기 버튼이 아래 글 목록까지 내려가면 숨겨져 버리는데,

z-index 값을 높여서 상위로 띄우는 건 어떨까요?

<div id="float-comment" class="p-3 gap-2 mt-3" style="left: 935px; top: auto; right: auto; visibility: visible; z-index: 999; bottom: 5px !important; padding-right: 2.2rem !important;">
<button id="comment-write-button" data-bs-toggle="offcanvas" data-bs-target="#commentOffcanvas" aria-controls="commentOffcanvas" class="d-none"></button>
<button class="btn btn-primary btn-sm" style="width:95px" data-bs-toggle="offcanvas" data-bs-target="#commentOffcanvas" aria-controls="commentOffcanvas" onclick="comment_box('','w','산다는건');">
<i class="bi bi-pencil-square"></i>
댓글 등록
</button>
</div>