purityselect/resources/styles/@core/template/_default-layout-w-vertical-nav.scss

@use "vuetify/lib/styles/tools/elevation" as elevation;

.layout-wrapper.layout-nav-type-vertical {
  // 👉 Layout footer
  .layout-footer {
    $ele-layout-footer: &;

    .footer-content-container {
      // Sticky footer
      @at-root {
        // ℹ️ .layout-footer-sticky#{$ele-layout-footer} => .layout-footer-sticky.layout-wrapper.layout-nav-type-vertical .layout-footer
        .layout-footer-sticky#{$ele-layout-footer} {
          .footer-content-container {
            @include elevation.elevation(4);
          }
        }
      }
    }
  }
}