Fix various misalignments and overflows (#34227)

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Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

templates/repo/diff/box.tmpl

@@ -223,6 +223,7 @@
 	{{if and (not $.Repository.IsArchived) (not .DiffNotAvailable)}}
 		<template id="issue-comment-editor-template">
 			<form class="ui form comment">
+				<div class="field">
 				{{template "shared/combomarkdowneditor" (dict
 					"CustomInit" true
 					"MarkdownPreviewInRepo" $.Repository
@@ -230,12 +231,13 @@
 					"TextareaName" "content"
 					"DropzoneParentContainer" ".ui.form"
 				)}}
+				</div>
 				{{if .IsAttachmentEnabled}}
 					<div class="field">
 						{{template "repo/upload" .}}
 					</div>
 				{{end}}
-				<div class="tw-text-right edit buttons">
+				<div class="field flex-text-block tw-justify-end">
 					<button class="ui cancel button">{{ctx.Locale.Tr "repo.issues.cancel"}}</button>
 					<button class="ui primary button">{{ctx.Locale.Tr "repo.issues.save"}}</button>
 				</div>

templates/repo/diff/comment_form.tmpl

@@ -27,7 +27,7 @@
 		{{end}}
 
 		<div class="field footer">
-			<div class="tw-text-right">
+			<div class="flex-text-block tw-justify-end">
 				{{if $.reply}}
 					<button class="ui submit primary tiny button btn-reply" type="submit">{{ctx.Locale.Tr "repo.diff.comment.reply"}}</button>
 					<input type="hidden" name="reply" value="{{$.reply}}">