Styling Tabs

Is it possible to have border of tab like EClipse for example in CUBA? And how can we set background colour during the mouse-over event instead the text colour we have by default?

You can tune appearence of the TabSheet component with predefined styles. List of them you can find in documentation.

Custom style should be defined with CSS. For example, to set background colour during the mouse-over event on tab caption you should add this rule:

css
.#{$primary-stylename}-tabitemcell > .v-tabsheet-tabitem > .v-caption:hover {
  background-color: gray;
}