How to fix jumping menu.

Since you made some changes to the css, you will want to adjust the margin of .collapseomatic_content as follows:

.collapseomatic_content {
      margin: 0 0 0 16px;
}

Keep in mind, any changes made to the plugin’s css will be overwritten when you update the plugin. Much smarter is to add overwriting css definitions to your theme's style.css file and add the !important tag to override like so:

.collapseomatic_content {
      margin: 0 0 0 16px !important;
}

Can you dig it?

Great you where able to get it working for you. Please let others know it works for you: Vote for Pedro!