diff --git a/packages/client/src/components/MkAbuseReport.vue b/packages/client/src/components/MkAbuseReport.vue
index 33649c0868..259fe294af 100644
--- a/packages/client/src/components/MkAbuseReport.vue
+++ b/packages/client/src/components/MkAbuseReport.vue
@@ -101,7 +101,7 @@ function resolve() {
 		box-sizing: border-box;
 		text-align: left;
 		padding: 24px;
-		border-right: solid 1px var(--divider);
+		border-inline-end: solid 1px var(--divider);
 
 		> .info {
 			display: flex;
diff --git a/packages/client/src/components/MkGoogle.vue b/packages/client/src/components/MkGoogle.vue
index cec4930471..a0e86270f3 100644
--- a/packages/client/src/components/MkGoogle.vue
+++ b/packages/client/src/components/MkGoogle.vue
@@ -48,7 +48,7 @@ const search = () => {
 		margin: 0;
 		padding: 0 16px;
 		border: solid 1px var(--divider);
-		border-left: none;
+		border-inline-start: none;
 		border-radius: 0 4px 4px 0;
 
 		&:active {
diff --git a/packages/client/src/components/MkImageViewer.vue b/packages/client/src/components/MkImageViewer.vue
index 7190098f7b..bf49ee5dce 100644
--- a/packages/client/src/components/MkImageViewer.vue
+++ b/packages/client/src/components/MkImageViewer.vue
@@ -85,7 +85,7 @@ const modal = $ref<InstanceType<typeof MkModal>>();
 		> span + span {
 			margin-inline-start: 0.5em;
 			padding-inline-start: 0.5em;
-			border-left: solid 1px rgba(255, 255, 255, 0.5);
+			border-inline-start: solid 1px rgba(255, 255, 255, 0.5);
 		}
 	}
 }
diff --git a/packages/client/src/components/MkMediaCaption.vue b/packages/client/src/components/MkMediaCaption.vue
index ace65b22ee..6e7ee2004e 100644
--- a/packages/client/src/components/MkMediaCaption.vue
+++ b/packages/client/src/components/MkMediaCaption.vue
@@ -320,7 +320,7 @@ export default defineComponent({
 		> span + span {
 			margin-inline-start: 0.5em;
 			padding-inline-start: 0.5em;
-			border-left: solid 1px rgba(255, 255, 255, 0.5);
+			border-inline-start: solid 1px rgba(255, 255, 255, 0.5);
 		}
 	}
 }
diff --git a/packages/client/src/components/MkNote.vue b/packages/client/src/components/MkNote.vue
index daddbfd637..8b5a73a6bd 100644
--- a/packages/client/src/components/MkNote.vue
+++ b/packages/client/src/components/MkNote.vue
@@ -652,7 +652,7 @@ defineExpose({
 				display: block;
 				margin-bottom: -4px;
 				margin-top: 16px;
-				border-left: 2px solid currentColor;
+				border-inline-start: 2px solid currentColor;
 				margin-inline-start: calc((var(--avatarSize) / 2) - 1px);
 				opacity: 0.25;
 			}
@@ -749,7 +749,7 @@ defineExpose({
 				&::after {
 					content: "";
 					position: absolute;
-					border-left: 2px solid currentColor;
+					border-inline-start: 2px solid currentColor;
 					border-top: 2px solid currentColor;
 					margin-inline-start: calc(var(--avatarSize) / 2 - 1px);
 					width: calc(var(--avatarSize) / 2 + 14px);
diff --git a/packages/client/src/components/MkNoteSub.vue b/packages/client/src/components/MkNoteSub.vue
index 59a6faf30a..0156b5b992 100644
--- a/packages/client/src/components/MkNoteSub.vue
+++ b/packages/client/src/components/MkNoteSub.vue
@@ -656,7 +656,7 @@ function noteClick(e) {
 			&::before {
 				content: "";
 				position: absolute;
-				border-left: 2px solid currentColor;
+				border-inline-start: 2px solid currentColor;
 				margin-inline-start: calc((var(--avatarSize) / 2) - 1px);
 				width: calc(var(--indent) / 2);
 				inset-block: 0;
@@ -698,7 +698,7 @@ function noteClick(e) {
 			&::after {
 				content: "";
 				position: absolute;
-				border-left: 2px solid currentColor;
+				border-inline-start: 2px solid currentColor;
 				border-bottom: 2px solid currentColor;
 				margin-inline-start: calc((var(--avatarSize) / 2) - 1px);
 				width: calc(var(--indent) / 2);
diff --git a/packages/client/src/components/MkReactionsViewer.details.vue b/packages/client/src/components/MkReactionsViewer.details.vue
index a5eb5737b9..6af616790d 100644
--- a/packages/client/src/components/MkReactionsViewer.details.vue
+++ b/packages/client/src/components/MkReactionsViewer.details.vue
@@ -70,7 +70,7 @@ const emit = defineEmits<{
 		flex: 1;
 		min-width: 0;
 		font-size: 0.95em;
-		border-left: solid 0.5px var(--divider);
+		border-inline-start: solid 0.5px var(--divider);
 		padding-inline-start: 10px;
 		margin-inline-start: 10px;
 		margin-inline-end: 14px;
diff --git a/packages/client/src/components/MkTimeline.vue b/packages/client/src/components/MkTimeline.vue
index beb930b8ba..9ef659f9f4 100644
--- a/packages/client/src/components/MkTimeline.vue
+++ b/packages/client/src/components/MkTimeline.vue
@@ -305,7 +305,7 @@ const timetravel = (date?: Date) => {
 		}
 		i {
 			margin-inline-start: 0.7em;
-			border-left: 1px solid var(--accentedBg);
+			border-inline-start: 1px solid var(--accentedBg);
 			padding-inline-start: 0.4em;
 		}
 	}
diff --git a/packages/client/src/components/global/MkMisskeyFlavoredMarkdown.vue b/packages/client/src/components/global/MkMisskeyFlavoredMarkdown.vue
index e5ed1dc869..97f4d0a98e 100644
--- a/packages/client/src/components/global/MkMisskeyFlavoredMarkdown.vue
+++ b/packages/client/src/components/global/MkMisskeyFlavoredMarkdown.vue
@@ -356,7 +356,7 @@ const props = withDefaults(
 		margin: 8px 0;
 		padding-inline-start: 12px;
 		color: var(--fgTransparentWeak);
-		border-left: solid 4px var(--fgTransparent);
+		border-inline-start: solid 4px var(--fgTransparent);
 	}
 
 	::v-deep(pre) {
diff --git a/packages/client/src/pages/admin/index.vue b/packages/client/src/pages/admin/index.vue
index d9feb8574d..608905241b 100644
--- a/packages/client/src/pages/admin/index.vue
+++ b/packages/client/src/pages/admin/index.vue
@@ -454,7 +454,7 @@ defineExpose({
 			width: 32%;
 			max-width: 280px;
 			box-sizing: border-box;
-			border-right: solid 0.5px var(--divider);
+			border-inline-end: solid 0.5px var(--divider);
 			overflow: auto;
 			height: 100%;
 		}
diff --git a/packages/client/src/pages/messaging/messaging-room.message.vue b/packages/client/src/pages/messaging/messaging-room.message.vue
index 8fe84d81c3..6ddf4192c0 100644
--- a/packages/client/src/pages/messaging/messaging-room.message.vue
+++ b/packages/client/src/pages/messaging/messaging-room.message.vue
@@ -271,9 +271,9 @@ function del(): void {
 				&:not(.noText):before {
 					left: -14px;
 					border-top: solid 8px transparent;
-					border-right: solid 8px $color;
+					border-inline-end: solid 8px $color;
 					border-bottom: solid 8px transparent;
-					border-left: solid 8px transparent;
+					border-inline-start: solid 8px transparent;
 				}
 
 				> .content {
@@ -316,9 +316,9 @@ function del(): void {
 					right: -14px;
 					left: auto;
 					border-top: solid 8px transparent;
-					border-right: solid 8px transparent;
+					border-inline-end: solid 8px transparent;
 					border-bottom: solid 8px transparent;
-					border-left: solid 8px $me-balloon-color;
+					border-inline-start: solid 8px $me-balloon-color;
 				}
 
 				> .content {
diff --git a/packages/client/src/pages/welcome.entrance.b.vue b/packages/client/src/pages/welcome.entrance.b.vue
index 6d533190ae..a6e8a387d4 100644
--- a/packages/client/src/pages/welcome.entrance.b.vue
+++ b/packages/client/src/pages/welcome.entrance.b.vue
@@ -294,7 +294,7 @@ export default defineComponent({
 					> span:not(:last-child) {
 						padding-inline-end: 1em;
 						margin-inline-end: 1em;
-						border-right: solid 1px rgba(255, 255, 255, 0.5);
+						border-inline-end: solid 1px rgba(255, 255, 255, 0.5);
 					}
 				}
 			}
diff --git a/packages/client/src/pages/welcome.entrance.c.vue b/packages/client/src/pages/welcome.entrance.c.vue
index 035df0a264..b3d0c32f6d 100644
--- a/packages/client/src/pages/welcome.entrance.c.vue
+++ b/packages/client/src/pages/welcome.entrance.c.vue
@@ -315,7 +315,7 @@ export default defineComponent({
 							> span:not(:last-child) {
 								padding-inline-end: 1em;
 								margin-inline-end: 1em;
-								border-right: solid 0.5px var(--divider);
+								border-inline-end: solid 0.5px var(--divider);
 							}
 						}
 
diff --git a/packages/client/src/ui/_common_/navbar.vue b/packages/client/src/ui/_common_/navbar.vue
index 04c1242d4b..5fecef5827 100644
--- a/packages/client/src/ui/_common_/navbar.vue
+++ b/packages/client/src/ui/_common_/navbar.vue
@@ -265,7 +265,7 @@ function more(ev: MouseEvent) {
 			background: var(--navBg);
 		}
 		#calckey_app > .wallpaper:not(.centered) & {
-			border-right: 1px solid var(--divider);
+			border-inline-end: 1px solid var(--divider);
 		}
 		contain: strict;
 		display: flex;
diff --git a/packages/client/src/ui/deck.vue b/packages/client/src/ui/deck.vue
index 95cea282f7..bd50376dd0 100644
--- a/packages/client/src/ui/deck.vue
+++ b/packages/client/src/ui/deck.vue
@@ -451,10 +451,10 @@ async function deleteProfile() {
 
 			> .column {
 				flex-shrink: 0;
-				border-right: solid var(--deckDividerThickness) var(--bg);
+				border-inline-end: solid var(--deckDividerThickness) var(--bg);
 
 				&:first-of-type {
-					border-left: solid var(--deckDividerThickness) var(--bg);
+					border-inline-start: solid var(--deckDividerThickness) var(--bg);
 				}
 
 				&.folder {
diff --git a/packages/client/src/ui/universal.vue b/packages/client/src/ui/universal.vue
index 10c1c4b237..9f3bc2e80e 100644
--- a/packages/client/src/ui/universal.vue
+++ b/packages/client/src/ui/universal.vue
@@ -475,7 +475,7 @@ console.log(mainRouter.currentRoute.value.name);
 	}
 	&:not(.isMobile) {
 		> .contents {
-			border-right: 0.5px solid var(--divider);
+			border-inline-end: 0.5px solid var(--divider);
 		}
 	}
 	&.wallpaper {