@media only screen and (min-width: 749px){
   .twrbo-is-btn {
      display:none;
   }
}

@media only screen and (max-width: 749px){
   .twrbo-is-btn {
      width: 50%;
   }
   .btn1 {  
     left: 0;
     background: #007979;
   }
   .btn2 {
     right: 0;
     background: #24a09a;
   }
}