diff --git a/gui/main.qml b/gui/main.qml
index a98544d..9e72f1a 100644
--- a/gui/main.qml
+++ b/gui/main.qml
@@ -619,15 +619,30 @@ ApplicationWindow {
                     onClicked: callText.visible = !callText.visible
                 }
             }
-            Label {
+            Text {
                 id: callText
                 Layout.fillWidth: true
                 text: block.blockContent
+                textFormat: Text.PlainText
                 wrapMode: Text.Wrap
                 font.family: "monospace"
                 font.pixelSize: Qt.application.font.pixelSize * 0.85
-                opacity: 0.4
+                opacity: 0.7
                 visible: false
+                color: palette.text
+
+                onVisibleChanged: {
+                    if (visible && textFormat === Text.PlainText) {
+                        try {
+                            let obj = JSON.parse(block.blockContent)
+                            let pretty = JSON.stringify(obj, null, 2)
+                            text = chatModel.highlightedHtml(pretty, "json")
+                        } catch(e) {
+                            text = chatModel.highlightedHtml(block.blockContent, "json")
+                        }
+                        textFormat = Text.RichText
+                    }
+                }
             }
         }
     }
@@ -646,17 +661,43 @@ ApplicationWindow {
                     onClicked: toolText.visible = !toolText.visible
                 }
             }
-            Label {
+            Text {
                 id: toolText
                 Layout.fillWidth: true
                 text: block.blockContent
+                textFormat: Text.PlainText
                 wrapMode: Text.Wrap
                 font.family: "monospace"
                 font.pixelSize: Qt.application.font.pixelSize * 0.85
-                opacity: 0.4
+                opacity: 0.7
                 visible: false
-                maximumLineCount: 50
+                color: palette.text
+                maximumLineCount: 80
                 elide: Text.ElideRight
+
+                onVisibleChanged: {
+                    if (visible && textFormat === Text.PlainText) {
+                        let content = block.blockContent
+                        let trimmed = content.trimStart()
+                        let lang = ""
+                        if (trimmed.startsWith("{") || trimmed.startsWith("[")) lang = "json"
+                        else if (trimmed.startsWith("---") || trimmed.startsWith("diff ")) lang = "diff"
+
+                        if (lang === "json") {
+                            try {
+                                let obj = JSON.parse(content)
+                                let pretty = JSON.stringify(obj, null, 2)
+                                text = chatModel.highlightedHtml(pretty, "json")
+                            } catch(e) {
+                                text = chatModel.highlightedHtml(content, "json")
+                            }
+                            textFormat = Text.RichText
+                        } else if (lang) {
+                            text = chatModel.highlightedHtml(content, lang)
+                            textFormat = Text.RichText
+                        }
+                    }
+                }
             }
         }
     }