Adding upstream version 5.2.3+dfsg.

Signed-off-by: Daniel Baumann <daniel@debian.org>

site/assets/scss/_navbar.scss

@@ -0,0 +1,91 @@
+.bd-navbar {
+  padding: .75rem 0;
+  background-color: transparent;
+  background-image: linear-gradient(to bottom, rgba(var(--bd-violet-rgb), 1), rgba(var(--bd-violet-rgb), .95));
+  box-shadow: 0 .5rem 1rem rgba(0, 0, 0, .15), inset 0 -1px 0 rgba(0, 0, 0, .15);
+
+  .bd-navbar-toggle {
+    @include media-breakpoint-down(lg) {
+      width: 4.25rem;
+    }
+  }
+
+  .navbar-toggler {
+    padding: 0;
+    margin-right: -.5rem;
+    border: 0;
+
+    &:first-child {
+      margin-left: -.5rem;
+    }
+
+    .bi {
+      width: 1.5rem;
+      height: 1.5rem;
+    }
+
+    &:focus {
+      box-shadow: none;
+    }
+  }
+
+  .navbar-brand {
+    transition: .2s ease-in-out transform; // stylelint-disable-line property-disallowed-list
+
+    &:hover {
+      transform: rotate(-5deg) scale(1.1);
+    }
+  }
+
+  .navbar-toggler,
+  .nav-link {
+    padding-right: $spacer * .25;
+    padding-left: $spacer * .25;
+    color: rgba($white, .85);
+
+    &:hover,
+    &:focus {
+      color: $white;
+    }
+
+    &.active {
+      font-weight: 600;
+      color: $white;
+    }
+  }
+
+  .navbar-nav-svg {
+    display: inline-block;
+    vertical-align: -.125rem;
+  }
+
+  .offcanvas-lg {
+    background-color: var(--bd-violet);
+    border-left: 0;
+
+    @include media-breakpoint-down(lg) {
+      box-shadow: $box-shadow-lg;
+    }
+  }
+
+  .dropdown-toggle {
+    &:focus:not(:focus-visible) {
+      outline: 0;
+    }
+  }
+
+  .dropdown-menu {
+    --#{$prefix}dropdown-min-width: 12rem;
+    --#{$prefix}dropdown-link-hover-bg: rgba(var(--bd-violet-rgb), .1);
+    @include rfs(.875rem, --#{$prefix}dropdown-font-size);
+    box-shadow: $dropdown-box-shadow;
+  }
+
+  .dropdown-item.current {
+    font-weight: 600;
+    background-image: escape-svg($dropdown-active-icon);
+    background-repeat: no-repeat;
+    background-position: right $dropdown-item-padding-x top .6rem;
+    background-size: .75rem .75rem;
+  }
+}