diff --git a/src/utils/quickCss.ts b/src/utils/quickCss.ts
index ebf23cf48..14769fbb9 100644
--- a/src/utils/quickCss.ts
+++ b/src/utils/quickCss.ts
@@ -79,7 +79,7 @@ async function initThemes() {
     }
 
     themesStyle.textContent = links.map(link => `@import url("${link.trim()}");`).join("\n");
-    themesStyle.textContent += `:root{${cssVars.join("\n")}}`;
+    if (cssVars.length > 0) themesStyle.textContent += `:root{${cssVars.join("\n")}}`;
 }
 
 document.addEventListener("DOMContentLoaded", () => {