Hi,
Please check out updated mobile friendly codes https://themonic.com/customization-guide-for-iconic-one-pro-with-css-codes/
Remove this part from additional CSS:
.site-content {
width: 67.2%;
}
.widget-area {
width: 24.7%;
}if there are any other layout width elements in additional CSS remove them too.
You have also modified the style.css directly I think, as the following is limiting the width in mobile.
site-content {
width: 70%;
}I would suggest to reinstall the theme to get default style.css back and ask here with what you want to do.
Do not modify style.css directly as everything can be done via additional CSS, you can ask here if you face any issues.