diff --git a/frontend/src/topbar.ts b/frontend/src/topbar.ts
index f6754af..b9859cd 100644
--- a/frontend/src/topbar.ts
+++ b/frontend/src/topbar.ts
@@ -2,7 +2,8 @@
 
 export function setTopbarOffset() {
     const height = document.getElementById("topbar")!.getBoundingClientRect().height;
-    document.querySelector(":root")!.style = `--topbar-offset: ${height}px;`
+    const root: HTMLElement = document.querySelector(":root")!;
+    root.style.setProperty("--topbar-offset", `${height}px`);
 }
 
 export function addToggleDropdownListener() {