diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index be6424e6..bebf3976 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -78,6 +78,8 @@ dependencies {
 
     implementation("com.google.accompanist:accompanist-flowlayout:0.16.1")
     implementation("com.google.accompanist:accompanist-appcompat-theme:0.16.0")
+    implementation("com.google.accompanist:accompanist-insets:0.18.0")
+    implementation("com.google.accompanist:accompanist-insets-ui:0.18.0")
 
     implementation("io.coil-kt:coil-compose:1.3.2")
 
diff --git a/app/src/main/java/xyz/quaver/pupil/ui/ReaderActivity.kt b/app/src/main/java/xyz/quaver/pupil/ui/ReaderActivity.kt
index 33cd1b0e..2bb693e4 100644
--- a/app/src/main/java/xyz/quaver/pupil/ui/ReaderActivity.kt
+++ b/app/src/main/java/xyz/quaver/pupil/ui/ReaderActivity.kt
@@ -20,27 +20,28 @@ package xyz.quaver.pupil.ui
 
 import android.content.Intent
 import android.os.Bundle
-import android.view.*
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.viewModels
 import androidx.compose.material.MaterialTheme
 import androidx.compose.material.Scaffold
-import androidx.compose.material.TopAppBar
 import androidx.compose.material.Text
+import androidx.compose.material.TopAppBar
 import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.DateRange
-import androidx.compose.material.icons.filled.Science
+import androidx.compose.material.icons.filled.Fullscreen
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.livedata.observeAsState
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.res.stringResource
-import androidx.recyclerview.widget.LinearLayoutManager
+import androidx.core.view.WindowCompat
+import androidx.core.view.WindowInsetsCompat
+import androidx.core.view.WindowInsetsControllerCompat
 import com.google.accompanist.appcompattheme.AppCompatTheme
 import org.kodein.di.DIAware
 import org.kodein.di.android.closestDI
-import xyz.quaver.pupil.databinding.ReaderActivityBinding
+import xyz.quaver.pupil.R
 import xyz.quaver.pupil.ui.composable.FloatingActionButtonState
 import xyz.quaver.pupil.ui.composable.MultipleFloatingActionButton
 import xyz.quaver.pupil.ui.composable.SubFabItem
@@ -56,18 +57,38 @@ class ReaderActivity : ComponentActivity(), DIAware {
 
         setContent {
             var isFABExpanded by remember { mutableStateOf(FloatingActionButtonState.COLLAPSED) }
+            val isFullscreen by model.isFullscreen.observeAsState(false)
+
+            WindowInsetsControllerCompat(window, window.decorView).run {
+                if (isFullscreen) {
+                    hide(WindowInsetsCompat.Type.systemBars())
+                    systemBarsBehavior = WindowInsetsControllerCompat.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
+                } else
+                    show(WindowInsetsCompat.Type.systemBars())
+            }
 
             AppCompatTheme {
                 Scaffold(
                     topBar = {
-                        TopAppBar(
-                            title = { Text("Reader", color = MaterialTheme.colors.onSecondary) }
-                        )
+                        if (!isFullscreen)
+                            TopAppBar(
+                                title = {
+                                    Text(
+                                        "Reader",
+                                        color = MaterialTheme.colors.onSecondary
+                                    )
+                                }
+                            )
                     },
                     floatingActionButton = {
                         MultipleFloatingActionButton(
                             items = listOf(
-                                // TODO
+                                SubFabItem(
+                                    icon = Icons.Default.Fullscreen,
+                                    label = stringResource(id = R.string.reader_fab_fullscreen)
+                                ) {
+                                    model.isFullscreen.postValue(!isFullscreen)
+                                }
                             ),
                             targetState = isFABExpanded,
                             onStateChanged = {
diff --git a/app/src/main/java/xyz/quaver/pupil/ui/composable/MultipleFloatingActionButton.kt b/app/src/main/java/xyz/quaver/pupil/ui/composable/MultipleFloatingActionButton.kt
index aebb6b31..f649e5d4 100644
--- a/app/src/main/java/xyz/quaver/pupil/ui/composable/MultipleFloatingActionButton.kt
+++ b/app/src/main/java/xyz/quaver/pupil/ui/composable/MultipleFloatingActionButton.kt
@@ -24,7 +24,7 @@ import androidx.compose.ui.tooling.preview.PreviewParameterProvider
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
 
-enum class FloatingActionButtonState(val isExpanded: Boolean) {
+enum class FloatingActionButtonState(private val isExpanded: Boolean) {
     COLLAPSED(false), EXPANDED(true);
 
     operator fun not() = lookupTable[!this.isExpanded]!!
@@ -39,7 +39,8 @@ enum class FloatingActionButtonState(val isExpanded: Boolean) {
 
 data class SubFabItem(
     val icon: ImageVector,
-    val label: String? = null
+    val label: String? = null,
+    val onClick: ((SubFabItem) -> Unit)? = null
 )
 
 @Composable
@@ -97,7 +98,6 @@ private class FloatingActionButtonItemProvider : PreviewParameterProvider<SubFab
 fun MultipleFloatingActionButton(
     @PreviewParameter(provider = FloatingActionButtonItemProvider::class) items: List<SubFabItem>,
     fabIcon: ImageVector = Icons.Default.Add,
-    onItemClick: ((SubFabItem) -> Unit)? = null,
     targetState: FloatingActionButtonState = FloatingActionButtonState.COLLAPSED,
     onStateChanged: ((FloatingActionButtonState) -> Unit)? = null
 ) {
@@ -191,7 +191,7 @@ fun MultipleFloatingActionButton(
                 labelAlpha = labelAlpha,
                 labelOffset = labelOffset
             ) {
-                onItemClick?.invoke(it)
+                item.onClick?.invoke(it)
             }
         }
 
diff --git a/app/src/main/java/xyz/quaver/pupil/ui/viewmodel/ReaderViewModel.kt b/app/src/main/java/xyz/quaver/pupil/ui/viewmodel/ReaderViewModel.kt
index 56150b34..87c6ee1e 100644
--- a/app/src/main/java/xyz/quaver/pupil/ui/viewmodel/ReaderViewModel.kt
+++ b/app/src/main/java/xyz/quaver/pupil/ui/viewmodel/ReaderViewModel.kt
@@ -42,6 +42,8 @@ class ReaderViewModel(app: Application) : AndroidViewModel(app), DIAware {
 
     override val di by closestDI()
 
+    val isFullscreen = MutableLiveData(false)
+
     private val database: AppDatabase by instance()
 
     private val historyDao = database.historyDao()