用gtk inspector查看元素结构：

GTK_DEBUG=interactive gvim

@define-color VIM_BG_FIX #3C4C55;

window#vim-main-window {
    background-color: @VIM_BG_FIX;
}

window#vim-main-window notebook header {
    background-color: #1E272C;
    border-bottom-width: 0;
}
window#vim-main-window notebook tab {
    border-bottom-width: 0;
}
window#vim-main-window notebook tab label {
    padding-left:5px;
    padding-right:5px;
    padding-top:1px;
    padding-bottom:2px;
    color: #7CBDC6;
}
window#vim-main-window notebook tab:checked label {
    background-color: #7CBDC6;
    color: #1E272C;
}