Add bookstack integration

public/assets/css/thetool.css

@@ -783,10 +783,45 @@ td.controls {
   max-width: 100% !important;
 }
 
-.chevron-icon::before {
-  content: "\f077";
+.bookstack-integration-modal {
+  position: fixed;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  background: rgba(0,0,0,0.5);
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  z-index: 9999;
 }
 
-.collapsed .chevron-icon::before {
-  content: "\f078";
-}
+.bookstack-integration-modal-content {
+  background: white;
+  padding: 20px;
+  border-radius: 5px;
+  width: 80%;
+  height: 80%;
+  position: relative;
+  transition: opacity 0.3s ease;
+}
+
+.bookstack-integration-close-btn {
+  position: absolute;
+  right: -10px;
+  top: -10px;
+  background: red;
+  border: none;
+  color: white;
+  border-radius: 50%;
+  width: 25px;
+  height: 25px;
+  cursor: pointer;
+}
+
+.bookstack-integration-iframe {
+  width: 100%;
+  height: 100%;
+  border: 1px solid #ddd;
+  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
+}