iview/src/styles/components/loading-bar.less

@loading-bar-prefix-cls: ~"@{css-prefix}loading-bar";

.@{loading-bar-prefix-cls} {
    width: 100%;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: @zindex-loading-bar;

    &-inner {
        transition: width @transition-time linear;

        &-color-primary {
            background-color: @primary-color;
        }

        &-failed-color-error {
            background-color: @error-color;
        }
    }
}