Merge static and dynamic styles (#3950)

* Merge static and dynamic styles

---------

Co-authored-by: Jonathan Kelley <jkelleyrtp@gmail.com>

packages/playwright-tests/web/src/main.rs

@@ -63,6 +63,7 @@ fn app() -> Element {
         OnMounted {}
         WebSysClosure {}
         DocumentElements {}
+        MergeStyles {}
         SelectMultiple {}
     }
 }
@@ -156,6 +157,20 @@ fn DocumentElements() -> Element {
     }
 }
 
+// Regression test for https://github.com/DioxusLabs/dioxus/issues/3887
+#[component]
+fn MergeStyles() -> Element {
+    let px = 100;
+
+    rsx! {
+        div {
+            id: "merge-styles-div",
+            style: "width: {px}px; height: {px}px",
+            background_color: "red",
+        }
+    }
+}
+
 // Select elements have odd default behavior when you set the multiple attribute after mounting the element
 // Regression test for https://github.com/DioxusLabs/dioxus/issues/3185
 #[component]