As Andrew has stated in the theme setting u can modify some basic settings but if you want full control of what your tabs look like you will need to play with the CSS.

Here is an example of something i've been playing with for one of my forms.

.cf-pagination-tabs {
  
  
}

.cf-pagination-tabs li {
	position: relative;
	z-index: 1;
	white-space: nowrap;
  	background:none !important;
  	border:none !important;
}

.cf-pagination-tabs li {
	position: relative;
	display: inline-block;
	padding: 1.5em 1.5em 1em;
	text-decoration: none;
	margin: 0 -7px;
} 

.cf-pagination-tabs li::before {
	content: '';
	position: absolute;
	top: 0; 
    right: 0;
    bottom: .5em;
    left: 0;
	z-index: -1;
  	border: 1px solid #000;
	border-bottom: none;
	border-radius: 10px 10px 0 0;
	background: #ddd;
	box-shadow: 0 2px hsla(0,0%,100%,.5) inset;
	transform: perspective(5px) rotateX(2deg);
	transform-origin: bottom;
}


.cf-pagination-tabs li::before {
	transform-origin: bottom;
}


.cf-pagination-tabs li.active {
	z-index: 2;
}

.cf-pagination-tabs li.active::before {
	margin-bottom: -1px;
	border-top-width: 1px;
}

.cf-pagination-tabs li.active::before {
	background: #eee;
}
.cf-pagination-tabs li a{
   min-width: 90px;
  text-align:center;
  display:inline-block;
}