diff --git a/src/components/inline-tools/inline-tool-bold.ts b/src/components/inline-tools/inline-tool-bold.ts
index c3a4d9d2..38fe1125 100644
--- a/src/components/inline-tools/inline-tool-bold.ts
+++ b/src/components/inline-tools/inline-tool-bold.ts
@@ -34,11 +34,6 @@ export default class BoldInlineTool implements InlineTool {
     } as SanitizerConfig;
   }
 
-  /**
-   * Native Document's command that uses for Bold
-   */
-  private readonly commandName: string = 'bold';
-
   /**
    * Create button for Inline Toolbar
    */
@@ -47,12 +42,174 @@ export default class BoldInlineTool implements InlineTool {
       icon: IconBold,
       name: 'bold',
       onActivate: () => {
-        document.execCommand(this.commandName);
+        this.toggleBold();
+      },
+      isActive: () => {
+        const selection = window.getSelection();
+
+        return selection ? this.isSelectionBold(selection) : false;
       },
-      isActive: () => document.queryCommandState(this.commandName),
     };
   }
 
+  /**
+   * Apply or remove bold formatting using modern Selection API
+   */
+  private toggleBold(): void {
+    const selection = window.getSelection();
+
+    if (!selection || selection.rangeCount === 0) {
+      return;
+    }
+
+    const range = selection.getRangeAt(0);
+
+    if (range.collapsed) {
+      return;
+    }
+
+    // Check if selection is already wrapped in <b> tag
+    const isBold = this.isSelectionBold(selection);
+
+    if (isBold) {
+      // Unwrap: remove <b> tags while preserving content
+      this.unwrapBoldTags(range);
+    } else {
+      // Wrap: surround selection with <b> tag
+      this.wrapWithBold(range);
+    }
+  }
+
+  /**
+   * Check if current selection is within a <b> tag
+   *
+   * @param selection - The Selection object to check
+   */
+  private isSelectionBold(selection: Selection): boolean {
+    if (!selection || selection.rangeCount === 0) {
+      return false;
+    }
+
+    const range = selection.getRangeAt(0);
+    const container = range.commonAncestorContainer;
+
+    // Check if container itself is a <b> tag
+    if (container.nodeType === Node.ELEMENT_NODE && (container as Element).tagName === 'B') {
+      return true;
+    }
+
+    // Check if container is inside a <b> tag
+    let parent: Node | null = container.nodeType === Node.TEXT_NODE ? container.parentElement : container as Element;
+
+    while (parent && parent.nodeType === Node.ELEMENT_NODE) {
+      if ((parent as Element).tagName === 'B') {
+        return true;
+      }
+      parent = parent.parentElement;
+    }
+
+    return false;
+  }
+
+  /**
+   * Wrap selection with <b> tag
+   *
+   * @param range - The Range object containing the selection to wrap
+   */
+  private wrapWithBold(range: Range): void {
+    const bElement = document.createElement('b');
+
+    try {
+      range.surroundContents(bElement);
+    } catch (error) {
+      // If surroundContents fails (e.g., range spans multiple elements),
+      // extract content and wrap it
+      const contents = range.extractContents();
+
+      bElement.appendChild(contents);
+      range.insertNode(bElement);
+    }
+
+    // Restore selection
+    const selection = window.getSelection();
+
+    if (selection) {
+      selection.removeAllRanges();
+      const newRange = document.createRange();
+
+      newRange.selectNodeContents(bElement);
+      selection.addRange(newRange);
+    }
+  }
+
+  /**
+   * Remove <b> tags while preserving content
+   *
+   * @param range - The Range object containing the selection to unwrap
+   */
+  private unwrapBoldTags(range: Range): void {
+    const container = range.commonAncestorContainer;
+    let boldElement: HTMLElement | null = null;
+
+    // Find the <b> element
+    if (container.nodeType === Node.ELEMENT_NODE && (container as Element).tagName === 'B') {
+      boldElement = container as HTMLElement;
+    } else {
+      let parent: Node | null = container.nodeType === Node.TEXT_NODE ? container.parentElement : container as Element;
+
+      while (parent && parent.nodeType === Node.ELEMENT_NODE) {
+        if ((parent as Element).tagName === 'B') {
+          boldElement = parent as HTMLElement;
+          break;
+        }
+        parent = parent.parentElement;
+      }
+    }
+
+    if (boldElement) {
+      const selection = window.getSelection();
+
+      if (!selection || selection.rangeCount === 0) {
+        return;
+      }
+
+      // Save references to first and last child before unwrapping
+      const firstChild = boldElement.firstChild;
+      const lastChild = boldElement.lastChild;
+
+      // Replace <b> with its contents
+      const parent = boldElement.parentNode;
+
+      if (parent && firstChild && lastChild) {
+        // Insert all children before the bold element
+        while (boldElement.firstChild) {
+          parent.insertBefore(boldElement.firstChild, boldElement);
+        }
+        parent.removeChild(boldElement);
+
+        // Restore selection to the unwrapped content
+        selection.removeAllRanges();
+        const newRange = document.createRange();
+
+        if (firstChild === lastChild && firstChild.nodeType === Node.TEXT_NODE) {
+          // Single text node: try to preserve offsets
+          const textLength = firstChild.textContent?.length ?? 0;
+          const start = Math.min(range.startOffset, textLength);
+          const end = Math.min(range.endOffset, textLength);
+
+          newRange.setStart(firstChild, start);
+          newRange.setEnd(firstChild, end);
+        } else {
+          // Multiple nodes: select from first to last
+          newRange.setStartBefore(firstChild);
+          newRange.setEndAfter(lastChild);
+        }
+
+        selection.addRange(newRange);
+      }
+    }
+  }
+
   /**
    * Set a shortcut
    *