notebook_style.css

/*
 * This is an exmaple notebook_style file for VTerm tab bar.
 * This is not to be used directly.
 */

@define-color  tab_bg_color #28282B;
@define-color  checked_tab_bg_color #005880;
@define-color  fg_color #fcfcfc;

notebook header{
    /* No wasted space */
    padding: 0 0 0 0;
    margin: 0 0 0 0;
    min-height: 0;
    min-width: 0;

    /* No borders for header */
    border: 0 ;

    /* header background */
    background-color: @tab_bg_color;
}

notebook arrow {
    /* No wasted space */
    margin: 0 0 0 0;
    padding: 0 0 0 0;
    min-height: 0;
    min-width: 0;

    background-color: @tab_bg_color;
    color: @fg_color;
}

notebook arrow:disabled{
    color: darker(darker(@fg_color));
}

notebook > header > tabs > arrow.down{
    /* this is to snap arrow buttons to the edgs */
    margin-left: -8px;
    -gtk-icon-source: -gtk-icontheme("pan-start-symbolic");
}

notebook > header > tabs > arrow.up{
    /* this is to snap arrow buttons to the edgs */
    margin-right: -8px;
    -gtk-icon-source: -gtk-icontheme("pan-end-symbolic");

    /* this is to hide the right border of the leftmost tab */
    margin-left: -1px;
    border-width: 0px 0px 0 1px;
    border-style: solid;
    border-color: @tab_bg_color; 
}

/* Style all tabs */
notebook tab {
    /* negative left margin to overlab borders */;
    margin: 0px 0 0 -1px;
    padding: 2px 5px 2px 5px;
    min-height: 0;
    min-width: 0;

    background-color: @tab_bg_color;

    border-image: none;
    border-width: 0px 1px 0 1px;
    border-style: solid;
    border-color: @fg_color; 

    color: @fg_color; 

    font: 12px Hack;
}

/* Style active tab */
notebook tab:checked {
    background-color: @checked_tab_bg_color;
}