uas-platform/frontend/uas-web/app/main/MainTabPanel.scss

.#{$prefix}panel-header-main {
    background-color: $color-light;
    padding: 0 30px;

    .#{$prefix}btn-default-small {
        background-color: transparent;
        border-width: 0;
        padding: 6px 7px 6px 7px;

        .#{$prefix}btn-icon-el-default-small {
            color: $color-gray;
            min-height: 20px;
            font-size: 20px;
            line-height: 20px;
        }

        &.#{$prefix}btn-pressed,&.#{$prefix}btn-focus,&.#{$prefix}btn-focus.#{$prefix}btn-pressed {
            outline: 0;
            box-shadow: none !important;
            background-color: transparent;

            .#{$prefix}btn-icon-el-default-small {
                color: $base-color;
            }
        }
    }
}