diff --git a/app/src/main/kotlin/com/hippo/ehviewer/client/EhEngine.kt b/app/src/main/kotlin/com/hippo/ehviewer/client/EhEngine.kt
index e565d01a8..ad9a3d39b 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/client/EhEngine.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/client/EhEngine.kt
@@ -278,7 +278,7 @@ object EhEngine {
         ehRequest(location, url).fetchUsingAsText {
             val document = Jsoup.parse(this)
             val elements = document.select("#chd + p")
-            if (elements.size > 0) {
+            if (elements.isNotEmpty()) {
                 throw EhException(elements[0].text())
             }
             GalleryDetailParser.parseComments(document)
diff --git a/app/src/main/kotlin/com/hippo/ehviewer/client/EhTagDatabase.kt b/app/src/main/kotlin/com/hippo/ehviewer/client/EhTagDatabase.kt
index 0b383db2f..3a6d3709d 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/client/EhTagDatabase.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/client/EhTagDatabase.kt
@@ -32,7 +32,6 @@ import io.ktor.client.HttpClient
 import io.ktor.client.request.prepareGet
 import io.ktor.client.statement.bodyAsChannel
 import java.io.File
-import java.nio.charset.StandardCharsets
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
@@ -133,7 +132,7 @@ object EhTagDatabase : CoroutineScope {
     fun isTranslatable(context: Context): Boolean = context.resources.getBoolean(R.bool.tag_translatable)
 
     private fun getFileContent(file: File): String? = runCatching {
-        file.source().buffer().use { it.readString(StandardCharsets.UTF_8) }
+        file.source().buffer().use { it.readUtf8() }
     }.getOrNull()
 
     private fun checkData(sha1: String?, data: File): Boolean = sha1 != null && sha1 == data.toOkioPath().sha1()
diff --git a/app/src/main/kotlin/com/hippo/ehviewer/ui/UrlOpener.kt b/app/src/main/kotlin/com/hippo/ehviewer/ui/UrlOpener.kt
index b54376b61..5cb2f63d3 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/ui/UrlOpener.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/ui/UrlOpener.kt
@@ -36,11 +36,7 @@ fun Context.openBrowser(url: String) {
     }
 }
 
-context(Context, DestinationsNavigator)
-fun Context.jumpToReaderByPage(
-    url: String,
-    detail: GalleryDetail,
-): Boolean {
+fun DestinationsNavigator.jumpToReaderByPage(url: String, detail: GalleryDetail): Boolean {
     GalleryPageUrlParser.parse(url)?.let {
         if (it.gid == detail.gid) {
             navToReader(detail.galleryInfo, it.page)
diff --git a/app/src/main/kotlin/com/hippo/ehviewer/ui/reader/PagerViewer.kt b/app/src/main/kotlin/com/hippo/ehviewer/ui/reader/PagerViewer.kt
index 5e0a9812f..e502e8ec0 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/ui/reader/PagerViewer.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/ui/reader/PagerViewer.kt
@@ -8,7 +8,6 @@ import androidx.compose.foundation.pager.PagerState
 import androidx.compose.foundation.pager.VerticalPager
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
-import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
diff --git a/app/src/main/kotlin/com/jamal/composeprefs3/ui/PrefsUtils.kt b/app/src/main/kotlin/com/jamal/composeprefs3/ui/PrefsUtils.kt
index f441fa900..247ea7a29 100644
--- a/app/src/main/kotlin/com/jamal/composeprefs3/ui/PrefsUtils.kt
+++ b/app/src/main/kotlin/com/jamal/composeprefs3/ui/PrefsUtils.kt
@@ -1,13 +1,7 @@
 package com.jamal.composeprefs3.ui
 
 import androidx.compose.runtime.Composable
-import java.math.BigDecimal
-import java.math.RoundingMode
 
 fun Any?.ifNotNullThen(content: @Composable () -> Unit): (@Composable () -> Unit)? = if (this != null) content else null
 
 fun Boolean.ifTrueThen(content: @Composable () -> Unit): (@Composable () -> Unit)? = if (this) content else null
-
-fun roundToDP(value: Double, places: Int): Double = BigDecimal(value).setScale(places, RoundingMode.HALF_EVEN).toDouble()
-
-fun roundToDP(value: Float, places: Int): Float = BigDecimal(value.toDouble()).setScale(places, RoundingMode.HALF_EVEN).toFloat()