.nuclide-workspace-views-toggle-button .nuclide-workspace-views-toggle-button-inner {
    background-color: @base-color;
}

.nuclide-workspace-views-panel {
    position: relative;

    &-handle {
        position: absolute;
        opacity: 0;
        z-index: 10;

        .left &, .right & {
            top: 0;
            bottom: 0;
        }

        .bottom &, .top & {
            left: 0;
            right: 0;
        }

        .bottom & {
            top: 0;
        }

        .top & {
            bottom: 0;
        }

        .left & {
            right: 0;
        }

        .right & {
            left: 0;
        }
    }
}

.nuclide-workspace-views {
    &-toggle-button .nuclide-workspace-views-toggle-button-inner {
        background-color: @base-color;
    }

    &-panel {
        position: relative;

        &-handle {
            position: absolute;
            opacity: 0;
            z-index: 10;

            .left &, .right & {
                top: 0;
                bottom: 0;
            }

            .bottom &, .top & {
                left: 0;
                right: 0;
            }

            .bottom & {
                top: 0;
            }

            .top & {
                bottom: 0;
            }

            .left & {
                right: 0;
            }

            .right & {
                left: 0;
            }
        }
    }

    .amu-use-animations & {
        &-panel-mask:not(:active) {
            transition:
                height 250ms @md-timing-function,
                width 250ms @md-timing-function;
        }
    }
}

Add animations to Nuclide's panels
Add animations to Nuclide's panels
