diff --git a/src/preview-mode/custom-element/SpoilerSpanElement.ts b/src/preview-mode/custom-element/SpoilerSpanElement.ts
new file mode 100644
index 0000000..b3c5cc8
--- /dev/null
+++ b/src/preview-mode/custom-element/SpoilerSpanElement.ts
@@ -0,0 +1,19 @@
+export class SpoilerSpanElement extends HTMLElement {
+    constructor() {
+        super();
+    }
+    clickListener = (evt: MouseEvent) => {
+        let curTarget = evt.currentTarget as HTMLElement;
+        if (curTarget.getAttribute("revealed") === null) {
+            curTarget.setAttribute("revealed", "");
+        } else {
+            curTarget.removeAttribute("revealed");
+        }
+    }
+    connectedCallback() {
+        this.addEventListener("click", this.clickListener);
+    }
+    disconnectedCallback() {
+        this.removeEventListener("click", this.clickListener);
+    }
+}
\ No newline at end of file
diff --git a/src/preview-mode/custom-element/index.ts b/src/preview-mode/custom-element/index.ts
new file mode 100644
index 0000000..5f4f415
--- /dev/null
+++ b/src/preview-mode/custom-element/index.ts
@@ -0,0 +1 @@
+export * from "./SpoilerSpanElement";
\ No newline at end of file