Nuxt build css optimize cause broken style.

[toshusai]

In development mode.
.spectrum-TreeView-itemLink has below styles.

    padding-top: var(--spectrum-treeview-item-text-padding-top);
    padding-bottom: var(--spectrum-treeview-item-text-padding-bottom);
    padding-left: var(--spectrum-treeview-item-affordance-size);
    padding-right: var(--spectrum-treeview-item-affordance-size);

In production (nuxt generate)

    padding: var(--spectrum-treeview-item-text-padding-top) var(--spectrum-treeview-item-affordance-size) var(--spectrum-treeview-item-text-padding-bottom);

padding-right is missing. So TreeView don't show Chevron.

What is the cause of this problem? webpack in Nuxt?, css-loader?, or Spectrum CSS?
Look like var(--spectrum-treeview-item-text-padding-bottom) is not defined. Is this cause of missing padding-right?

Anyway, we need to investigate.