Clicking to open dropdown menu on iPhone doesn't work

1. Go to edit code window, search for file 'dropdown-menu.liquid', look for line

<span class="expand"><i class="fa fa-angle-down"></i></span>

2. Change that line to 

<a href="javascript:;" class="expand"><i class="fa fa-angle-down"></i></a>

3. Open file 'theme-style.scss.liquid' (or 'bc.style.scss.liquid' on other themes), look for the code below

add: padding: 0; display: inline-block (Only add padding: 0 if the arrow isn't displayed fine)