Question

How can i reduce the height of the tabs as given in this jsfiddle
How to do that?

Answer 1

You need to override the most specific css selector for that element, which in this case would mean this, to completely remove the top and bottom padding:

.ui-navbar-noicons li .ui-btn .ui-btn-inner, .ui-navbar-noicons .ui-navbar-toggle .ui-btn-inner {
    padding-top: 0px;
    padding-bottom: 0px;
}