Fill background of info panel arrow

Author: wenli-cai

workflow-trace-viewer/src/jvmMain/kotlin/com/squareup/workflow1/traceviewer/ui/WorkflowInfoPanel.kt

@@ -12,12 +12,14 @@ import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material.Card
 import androidx.compose.material.Icon
 import androidx.compose.material.IconButton
 import androidx.compose.material.MaterialTheme
 import androidx.compose.material.Text
 import androidx.compose.material.icons.Icons.AutoMirrored.Filled
+import androidx.compose.material.icons.Icons.AutoMirrored.Rounded
 import androidx.compose.material.icons.automirrored.filled.KeyboardArrowLeft
 import androidx.compose.material.icons.automirrored.filled.KeyboardArrowRight
 import androidx.compose.runtime.Composable
@@ -27,6 +29,7 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextAlign
@@ -55,6 +58,9 @@ internal fun RightInfoPanel(
     IconButton(
       onClick = { panelOpen = !panelOpen },
       modifier = Modifier
+        .size(40.dp)
+        .clip(CircleShape)
+        .background(Color.White)
         .padding(8.dp)
         .size(40.dp)
         .align(Alignment.Top)