diff --git a/backend/app/controllers/posts_controller.rb b/backend/app/controllers/posts_controller.rb
index 2ee9d53..5bfbdb1 100644
--- a/backend/app/controllers/posts_controller.rb
+++ b/backend/app/controllers/posts_controller.rb
@@ -148,7 +148,8 @@ class PostsController < ApplicationController
                                          original_created_from: params[:original_created_from],
                                          original_created_before: params[:original_created_before],
                                          parent_post_ids: parse_parent_post_ids,
-                                         video_ms: params[:video_ms] }).create!
+                                         video_ms: params[:video_ms],
+                                         duration: params[:duration] }).create!
 
     post.reload
     render json: PostRepr.base(post), status: :created
diff --git a/frontend/src/components/TopNav.tsx b/frontend/src/components/TopNav.tsx
index 9524311..fe9cdd9 100644
--- a/frontend/src/components/TopNav.tsx
+++ b/frontend/src/components/TopNav.tsx
@@ -18,7 +18,7 @@ import type { FC, MouseEvent } from 'react'
 
 import type { Material, Menu, MenuVisibleItem, Tag, User } from '@/types'
 
-type Props = { user: User | null }
+type Props = { user: User | null, }
 
 
 export const menuOutline = (
diff --git a/frontend/src/components/posts/import/PostImportRowForm.tsx b/frontend/src/components/posts/import/PostImportRowForm.tsx
index 31c068b..4200a5c 100644
--- a/frontend/src/components/posts/import/PostImportRowForm.tsx
+++ b/frontend/src/components/posts/import/PostImportRowForm.tsx
@@ -4,6 +4,7 @@ import PostOriginalCreatedTimeField from '@/components/PostOriginalCreatedTimeFi
 import FieldError from '@/components/common/FieldError'
 import FieldWarning from '@/components/common/FieldWarning'
 import FormField from '@/components/common/FormField'
+import TextArea from '@/components/common/TextArea'
 import ThumbnailPreview from '@/components/posts/import/ThumbnailPreview'
 import { inputClass } from '@/lib/utils'
 
@@ -259,13 +260,13 @@ const PostImportAreaField = (
     <FormField label={label} messages={errors}>
       {({ describedBy, invalid }) => (
 	  <>
-	    <textarea
+	    <TextArea
 		value={value}
 		rows={4}
 		onChange={ev => onChange (ev.target.value)}
 		aria-describedby={describedBy}
-		aria-invalid={invalid}
-		className={inputClass (invalid)}/>
+		invalid={invalid}
+		className="h-auto"/>
 	    <FieldWarning messages={warnings}/>
 	  </>)}
     </FormField>)
diff --git a/frontend/src/pages/posts/PostImportResultPage.tsx b/frontend/src/pages/posts/PostImportResultPage.tsx
index a4509b6..5124e3b 100644
--- a/frontend/src/pages/posts/PostImportResultPage.tsx
+++ b/frontend/src/pages/posts/PostImportResultPage.tsx
@@ -1,7 +1,6 @@
 import { useEffect, useMemo, useState } from 'react'
 import { Helmet } from 'react-helmet-async'
-import { useNavigate,
-	 useParams } from 'react-router-dom'
+import { useNavigate, useParams } from 'react-router-dom'
 
 import FieldError from '@/components/common/FieldError'
 import PageTitle from '@/components/common/PageTitle'
@@ -26,9 +25,8 @@ import Forbidden from '@/pages/Forbidden'
 
 import type { FC } from 'react'
 
-import type { PostImportResultRow,
-	      PostImportRow,
-	      PostImportSession } from '@/lib/postImportSession'
+import type { PostImportResultRow, PostImportRow } from '@/lib/postImportSession'
+import type { PostImportSession } from '@/lib/postImportSession'
 import type { User } from '@/types'
 
 type Props = { user: User | null }
@@ -38,184 +36,184 @@ const rowMessages = (row: PostImportRow): string[] =>
 
 
 const PostImportResultPage: FC<Props> = ({ user }) => {
-    const editable = canEditContent (user)
-    const navigate = useNavigate ()
-    const { sessionId } = useParams ()
+  const editable = canEditContent (user)
+  const navigate = useNavigate ()
+  const { sessionId } = useParams ()
 
-    const [session, setSession] = useState<PostImportSession | null> (null)
-    const [missing, setMissing] = useState (false)
-    const [loadingRow, setLoadingRow] = useState<number | null> (null)
+  const [session, setSession] = useState<PostImportSession | null> (null)
+  const [missing, setMissing] = useState (false)
+  const [loadingRow, setLoadingRow] = useState<number | null> (null)
 
-    useEffect (() => {
-	if (sessionId == null)
-	  return
+  useEffect (() => {
+    if (sessionId == null)
+      return
 
-	const loaded = loadPostImportSession (sessionId, message =>
-	    toast ({ title: '取込状態を復元できませんでした', description: message }))
-	setSession (loaded)
-	setMissing (loaded == null)
-    }, [sessionId])
+    const loaded = loadPostImportSession (sessionId, message =>
+	toast ({ title: '取込状態を復元できませんでした', description: message }))
+    setSession (loaded)
+    setMissing (loaded == null)
+  }, [sessionId])
 
-    useEffect (() => {
-	if (sessionId == null || session == null)
-	  return
+  useEffect (() => {
+    if (sessionId == null || session == null)
+      return
 
-	savePostImportSession (sessionId, session, message =>
-	    toast ({ title: '取込状態を保存できませんでした', description: message }))
-    }, [session, sessionId])
+    savePostImportSession (sessionId, session, message =>
+	toast ({ title: '取込状態を保存できませんでした', description: message }))
+  }, [session, sessionId])
 
-    const counts = useMemo (
-	() => resultSummaryCounts (session?.rows ?? []),
-	[session])
+  const counts = useMemo (
+      () => resultSummaryCounts (session?.rows ?? []),
+      [session])
 
-    const retry = async (sourceRow: number) => {
-	if (session == null || sessionId == null)
-	  return
+  const retry = async (sourceRow: number) => {
+    if (session == null || sessionId == null)
+      return
 
-	setLoadingRow (sourceRow)
-	try
-	{
-	    const pendingRows = retryImportRow (session.rows, sourceRow)
-	    setSession ({ ...session, rows: pendingRows })
-	    const validated = await apiPost<{ rows: PostImportRow[] }> ('/posts/import/validate', {
-		rows: pendingRows
-		    .filter (row => row.importStatus !== 'created')
-		    .map (row => ({
-			sourceRow: row.sourceRow,
-			url: row.url,
-			attributes: row.attributes,
-			provenance: row.provenance,
-			tagSources: row.tagSources,
-			metadataUrl: row.metadataUrl })),
-		changed_row: -1 })
-	    const validatedRows = mergeValidatedImportRows (
-		pendingRows,
-		initialisePreviewRows (validated.rows))
-	    const nextSession = {
-		...session,
-		rows: validatedRows,
-		repairMode: 'failed' as const }
-	    setSession (nextSession)
-	    const target = validatedRows.find (_1 => _1.sourceRow === sourceRow)
-	    if (target == null)
-	      return
-	    if (Object.keys (target.validationErrors ?? { }).length > 0)
-	      {
-		const saved = savePostImportSession (sessionId, nextSession, message =>
-		    toast ({ title: '取込状態を保存できませんでした', description: message }))
-		if (saved)
-		  navigate (`/posts/import/${ sessionId }/review?edit=${ sourceRow }`)
-		return
-	      }
-
-	    const result = await apiPost<{
-		created: number
-		skipped: number
-		failed:  number
-		rows:    PostImportResultRow[] }> ('/posts/import', {
-		    rows: [{
-			sourceRow: target.sourceRow,
-			url: target.url,
-			attributes: target.attributes,
-			provenance: target.provenance,
-			tagSources: target.tagSources,
-			metadataUrl: target.metadataUrl }] })
-	    const mergedRows = mergeImportResults (nextSession.rows, result.rows)
-	    const recoverableRows = result.rows.filter (row =>
-		row.status === 'failed'
-		&& row.recoverable
-		&& Object.keys (row.errors ?? { }).length > 0)
-	    const nextRows = mergedRows.map (row => {
-		const recoverable = recoverableRows.find (_1 => _1.sourceRow === row.sourceRow)
-		if (recoverable == null)
-		  return row
-		return {
-		    ...row,
-		    importStatus: 'pending',
-		    validationErrors: recoverable.errors ?? { },
-		    importErrors: undefined }
-	    })
-	    const recoverableTarget = nextRows.find (_1 => _1.sourceRow === sourceRow)
-	    const resultSession = {
-		...nextSession,
-		rows: nextRows,
-		repairMode: recoverableTarget == null ? 'all' as const : 'failed' as const }
-	    setSession (resultSession)
-	    if (recoverableTarget != null
-		&& Object.keys (recoverableTarget.validationErrors).length > 0)
-	      {
-		const saved = savePostImportSession (sessionId, resultSession, message =>
-		    toast ({ title: '取込状態を保存できませんでした', description: message }))
-		if (saved)
-		  navigate (`/posts/import/${ sessionId }/review?edit=${ sourceRow }`)
-		return
-	      }
-	}
-	catch
-	{
-	    setSession (session)
-	    toast ({ title: '再試行に失敗しました' })
-	}
-	finally
-	{
-	    setLoadingRow (null)
-	}
-    }
-
-    const openRepair = (sourceRow: number) => {
-	if (session == null || sessionId == null)
-	  return
-
-	const nextSession = { ...session, repairMode: 'failed' as const }
-	setSession (nextSession)
-	const saved = savePostImportSession (sessionId, nextSession, message =>
-	    toast ({ title: '取込状態を保存できませんでした', description: message }))
-	if (!(saved))
-	  return
-	navigate (`/posts/import/${ sessionId }/review?edit=${ sourceRow }`)
-    }
-
-    if (!(editable))
-      return <Forbidden/>
-
-    if (missing || sessionId == null || session == null)
+    setLoadingRow (sourceRow)
+    try
       {
-	return (
-	    <MainArea>
-	      <div className="mx-auto max-w-4xl space-y-4 p-4">
-		<PageTitle>投稿インポート結果</PageTitle>
-		<FieldError messages={['取込状態が見つかりません．']}/>
-		<Button type="button" onClick={() => navigate ('/posts/import')}>
-		  URL リスト入力へ戻る
-		</Button>
-	      </div>
-	    </MainArea>)
+	const pendingRows = retryImportRow (session.rows, sourceRow)
+	setSession ({ ...session, rows: pendingRows })
+	const validated = await apiPost<{ rows: PostImportRow[] }> ('/posts/import/validate', {
+	    rows: pendingRows
+		.filter (row => row.importStatus !== 'created')
+		.map (row => ({
+		    sourceRow: row.sourceRow,
+		    url: row.url,
+		    attributes: row.attributes,
+		    provenance: row.provenance,
+		    tagSources: row.tagSources,
+		    metadataUrl: row.metadataUrl })),
+	    changed_row: -1 })
+	const validatedRows = mergeValidatedImportRows (
+	    pendingRows,
+	    initialisePreviewRows (validated.rows))
+	const nextSession = {
+	    ...session,
+	    rows: validatedRows,
+	    repairMode: 'failed' as const }
+	setSession (nextSession)
+	const target = validatedRows.find (_1 => _1.sourceRow === sourceRow)
+	if (target == null)
+	  return
+	if (Object.keys (target.validationErrors ?? { }).length > 0)
+	  {
+	    const saved = savePostImportSession (sessionId, nextSession, message =>
+		toast ({ title: '取込状態を保存できませんでした', description: message }))
+	    if (saved)
+	      navigate (`/posts/import/${ sessionId }/review?edit=${ sourceRow }`)
+	    return
+	  }
+
+	const result = await apiPost<{
+	    created: number
+	    skipped: number
+	    failed:  number
+	    rows:    PostImportResultRow[] }> ('/posts/import', {
+		rows: [{
+		    sourceRow: target.sourceRow,
+		    url: target.url,
+		    attributes: target.attributes,
+		    provenance: target.provenance,
+		    tagSources: target.tagSources,
+		    metadataUrl: target.metadataUrl }] })
+	const mergedRows = mergeImportResults (nextSession.rows, result.rows)
+	const recoverableRows = result.rows.filter (row =>
+	    row.status === 'failed'
+	    && row.recoverable
+	    && Object.keys (row.errors ?? { }).length > 0)
+	const nextRows = mergedRows.map (row => {
+	  const recoverable = recoverableRows.find (_1 => _1.sourceRow === row.sourceRow)
+	  if (recoverable == null)
+	    return row
+	  return {
+	      ...row,
+	      importStatus: 'pending',
+	      validationErrors: recoverable.errors ?? { },
+	      importErrors: undefined }
+	})
+	const recoverableTarget = nextRows.find (_1 => _1.sourceRow === sourceRow)
+	const resultSession = {
+	    ...nextSession,
+	    rows: nextRows,
+	    repairMode: recoverableTarget == null ? 'all' as const : 'failed' as const }
+	setSession (resultSession)
+	if (recoverableTarget != null
+	    && Object.keys (recoverableTarget.validationErrors).length > 0)
+	  {
+	    const saved = savePostImportSession (sessionId, resultSession, message =>
+		toast ({ title: '取込状態を保存できませんでした', description: message }))
+	    if (saved)
+	      navigate (`/posts/import/${ sessionId }/review?edit=${ sourceRow }`)
+	    return
+	  }
       }
+    catch
+      {
+	setSession (session)
+	toast ({ title: '再試行に失敗しました' })
+      }
+    finally
+      {
+	setLoadingRow (null)
+      }
+  }
 
-    return (
-	<MainArea>
-	  <Helmet>
-	    <title>{`投稿インポート結果 | ${ SITE_TITLE }`}</title>
-	  </Helmet>
+  const openRepair = (sourceRow: number) => {
+    if (session == null || sessionId == null)
+      return
 
-	  <div className="mx-auto max-w-5xl space-y-4 p-4">
-	    <PageTitle>登録結果</PageTitle>
+    const nextSession = { ...session, repairMode: 'failed' as const }
+    setSession (nextSession)
+    const saved = savePostImportSession (sessionId, nextSession, message =>
+	toast ({ title: '取込状態を保存できませんでした', description: message }))
+    if (!(saved))
+      return
+    navigate (`/posts/import/${ sessionId }/review?edit=${ sourceRow }`)
+  }
 
-	    <div className="text-sm text-neutral-700 dark:text-neutral-200">
-	      登録成功 {counts.created}件　スキップ {counts.skipped}件　失敗 {counts.failed}件
+  if (!(editable))
+    return <Forbidden/>
+
+  if (missing || sessionId == null || session == null)
+    {
+      return (
+	  <MainArea>
+	    <div className="mx-auto max-w-4xl space-y-4 p-4">
+	      <PageTitle>投稿インポート結果</PageTitle>
+	      <FieldError messages={['取込状態が見つかりません．']}/>
+	      <Button type="button" onClick={() => navigate ('/posts/import')}>
+		URL リスト入力へ戻る
+	      </Button>
 	    </div>
+	  </MainArea>)
+    }
 
-	    <div className="space-y-3">
-	      {session.rows.map (row => {
-		  const displayStatus = displayPostImportStatus (row)
-		  const canEdit = row.importStatus === 'failed'
-		  const canRetry =
-		      row.importStatus === 'failed'
-		      && Object.keys (row.validationErrors).length === 0
-		  return (
-		      <div
-			  key={row.sourceRow}
-			  className="rounded-lg border p-4 transition-shadow hover:shadow-sm">
+  return (
+      <MainArea>
+	<Helmet>
+	  <title>{`投稿インポート結果 | ${ SITE_TITLE }`}</title>
+	</Helmet>
+
+	<div className="mx-auto max-w-5xl space-y-4 p-4">
+	  <PageTitle>登録結果</PageTitle>
+
+	  <div className="text-sm text-neutral-700 dark:text-neutral-200">
+	    登録成功 {counts.created}件　スキップ {counts.skipped}件　失敗 {counts.failed}件
+	  </div>
+
+	  <div className="space-y-3">
+	    {session.rows.map (row => {
+	      const displayStatus = displayPostImportStatus (row)
+	      const canEdit = row.importStatus === 'failed'
+	      const canRetry =
+		  row.importStatus === 'failed'
+		  && Object.keys (row.validationErrors).length === 0
+	      return (
+		  <div
+		      key={row.sourceRow}
+		      className="rounded-lg border p-4 transition-shadow hover:shadow-sm">
 		    <div className="flex flex-col gap-3 md:flex-row md:items-start
 				    md:justify-between">
 		      <div className="space-y-2">
@@ -248,14 +246,12 @@ const PostImportResultPage: FC<Props> = ({ user }) => {
 			      編輯
 			    </Button>)}
 			{canRetry && (
-			    <>
-			      <Button
-				  type="button"
-				  onClick={() => retry (row.sourceRow)}
-				  disabled={loadingRow === row.sourceRow}>
-				再試行
-			      </Button>
-			    </>)}
+			    <Button
+				type="button"
+				onClick={() => retry (row.sourceRow)}
+				disabled={loadingRow === row.sourceRow}>
+			      再試行
+			    </Button>)}
 		      </div>
 		    </div>
 		  </div>)})}
diff --git a/frontend/src/pages/posts/PostImportSourcePage.tsx b/frontend/src/pages/posts/PostImportSourcePage.tsx
index 9b07796..8015b72 100644
--- a/frontend/src/pages/posts/PostImportSourcePage.tsx
+++ b/frontend/src/pages/posts/PostImportSourcePage.tsx
@@ -6,13 +6,13 @@ import FieldError from '@/components/common/FieldError'
 import Form from '@/components/common/Form'
 import FormField from '@/components/common/FormField'
 import PageTitle from '@/components/common/PageTitle'
+import TextArea from '@/components/common/TextArea'
 import MainArea from '@/components/layout/MainArea'
 import { Button } from '@/components/ui/button'
 import { toast } from '@/components/ui/use-toast'
 import { SITE_TITLE } from '@/config'
 import { apiPost, isApiError } from '@/lib/api'
 import { canEditContent } from '@/lib/users'
-import { inputClass } from '@/lib/utils'
 import { countImportSourceLines,
 	 cleanupExpiredPostImportSessions,
 	 createPostImportSessionId,
@@ -158,14 +158,12 @@ const PostImportSourcePage: FC<Props> = ({ user }) => {
 	  <PageTitle>投稿インポート</PageTitle>
 	  <FormField label="URL リスト">
 	    {() => (
-		<textarea
+		<TextArea
 		    value={source}
 		    rows={14}
-		    aria-invalid={messages.length > 0 || sourceIssues.length > 0}
+		    invalid={messages.length > 0 || sourceIssues.length > 0}
 		    aria-describedby={sourceDescribedBy || undefined}
-		    className={inputClass (
-			messages.length > 0 || sourceIssues.length > 0,
-			'font-mono text-sm')}
+		    className="h-80 font-mono text-sm"
 		    onBlur={() => {
 		      savePostImportSourceDraft (source, message =>
 			  toast ({ title: '入力内容を保存できませんでした',