feat(app-content): Revise sidebar selection and content edge styling

Main content now has a subtle left divider and rounded left edge next
to the navigation. Selected nav and list items use a softly tinted
pill instead of a solid primary fill.

Signed-off-by: nfebe <fenn25.fn@gmail.com>

Author: nfebe

src/assets/NcAppNavigationItem.scss

@@ -28,18 +28,32 @@
 		}
 	}
 
-	// When .active class is applied, change color background of link and utils. The
-	// !important prevents the focus state to override the active state.
+	// !important so :focus-within does not override the active state.
 	&.active {
-		background-color: var(--color-primary-element) !important;
+		background-color: color-mix(in srgb, var(--color-primary-element) 16%, transparent) !important;
 
 		&:hover {
-			background-color: var(--color-primary-element-hover) !important;
+			background-color: color-mix(in srgb, var(--color-primary-element) 25%, transparent) !important;
 		}
 
-		// overwrite active text color
-		.app-navigation-entry-link, .app-navigation-entry-button {
-			color: var(--color-primary-element-text) !important;
+		&:not(.app-navigation-entry--editing) {
+			.app-navigation-entry-link,
+			.app-navigation-entry-button {
+				position: relative;
+				color: var(--color-main-text) !important;
+
+				&::before {
+					content: '';
+					position: absolute;
+					inset-block: var(--default-grid-baseline, 4px);
+					inset-inline-start: 0;
+					width: 3px;
+					background-color: var(--color-primary-element);
+					border-start-end-radius: 2px;
+					border-end-end-radius: 2px;
+					animation: nc-nav-stripe-in var(--animation-quick, 200ms) ease-out;
+				}
+			}
 		}
 	}
 	&:focus-within,
@@ -72,7 +86,7 @@
 		background-color: var(--color-background-dark) !important;
 	}
 	&.active .app-navigation-entry__actions:hover :deep(.button-vue) {
-		background-color: var(--color-primary-element) !important;
+		background-color: var(--color-primary-element-light-hover) !important;
 	}
 
 	/* hide deletion/collapse of subitems */
@@ -227,3 +241,14 @@
 		}
 	}
 }
+
+@keyframes nc-nav-stripe-in {
+	from {
+		transform: scaleY(0);
+		opacity: 0;
+	}
+	to {
+		transform: scaleY(1);
+		opacity: 1;
+	}
+}

src/components/NcAppContent/NcAppContent.vue

@@ -466,6 +466,12 @@ export default {
 	&:not(.app-content--has-list) {
 		overflow: auto;
 	}
+
+	@media only screen and (min-width: $breakpoint-mobile) {
+		border-inline-start: 1px solid var(--color-border);
+		border-start-start-radius: var(--body-container-radius);
+		border-end-start-radius: var(--body-container-radius);
+	}
 }
 
 .app-content-wrapper {

src/components/NcAppNavigation/NcAppNavigation.vue

@@ -354,9 +354,9 @@ function handleEsc(): void {
 	user-select: none;
 	flex-grow: 0;
 	flex-shrink: 0;
-	background-color: var(--color-main-background-blur, var(--color-main-background));
-	-webkit-backdrop-filter: var(--filter-background-blur, none);
-	backdrop-filter: var(--filter-background-blur, none);
+	// Frosted chrome lives on NcContent's wrapper; staying transparent
+	// keeps the nav and the rounded-edge cutouts on one surface.
+	background-color: transparent;
 
 	&--closed {
 		margin-inline-start: calc(-1 * min($navigation-width, var(--app-navigation-max-width)));

src/components/NcContent/NcContent.vue

@@ -235,6 +235,11 @@ function setAppNavigation(value: boolean): void {
 	height: var(--body-height);
 	overflow: hidden;
 	padding: 0;
+	// Frosted chrome owned at wrapper level so the nav area and the
+	// cutouts from NcAppContent's rounded start-edges share one surface.
+	background-color: var(--color-main-background-blur, var(--color-main-background));
+	backdrop-filter: var(--filter-background-blur, none);
+	-webkit-backdrop-filter: var(--filter-background-blur, none);
 
 	&:not(.with-sidebar--full) {
 		position: fixed;

src/components/NcListItem/NcListItem.vue

@@ -854,22 +854,22 @@ export default {
 	&--active,
 	&.active {
 		.list-item {
-			background-color: var(--color-primary-element);
-			color: var(--color-primary-element-text) !important;
+			background-color: var(--color-primary-element-light);
+			color: var(--color-primary-element-light-text) !important;
 
 			&:hover,
 			&:focus-within,
 			&:has(:focus-visible),
 			&:has(:active) {
-				background-color: var(--color-primary-element-hover);
+				background-color: var(--color-primary-element-light-hover);
 			}
 		}
 
 		.list-item-content__name,
 		.list-item-content__subname,
 		.list-item-content__details,
 		.list-item-details__details {
-			color: var(--color-primary-element-text) !important;
+			color: var(--color-primary-element-light-text) !important;
 		}
 	}
 	.list-item-content__name,