upgrade to bootstrap version 5

assets/sass/_bootswatch-5.scss

@@ -0,0 +1,112 @@
+// Litera 5.1.3
+// Bootswatch
+
+// Navbar
+
+.navbar {
+  font-size: $font-size-sm;
+
+  &.bg-dark {
+    background-color: $success !important;
+  }
+
+  &.bg-light {
+    background-color: $white !important;
+    border: 1px solid rgba(0, 0, 0, .1);
+
+    &.navbar-fixed-top {
+      border-width: 0 0 1px;
+    }
+
+    &.navbar-fixed-bottom {
+      border-width: 1px 0 0;
+    }
+  }
+}
+
+// Typography
+
+p {
+  font-family: $font-family-serif;
+}
+
+blockquote {
+  font-style: italic;
+}
+
+footer {
+  font-size: $font-size-sm;
+}
+
+.lead {
+  color: $gray-600;
+  font-family: $font-family-sans-serif;
+}
+
+// Tables
+
+table,
+.table {
+  font-size: $font-size-sm;
+}
+
+// Navs
+
+.nav,
+.breadcrumb,
+.pagination {
+  font-size: $font-size-sm;
+}
+
+.dropdown-menu {
+  font-size: $font-size-sm;
+}
+
+// Indicators
+
+.alert {
+  color: $white;
+  font-size: $font-size-sm;
+
+  &,
+  p {
+    font-family: $font-family-sans-serif;
+  }
+
+  a,
+  .alert-link {
+    color: $white;
+    font-weight: 400;
+    text-decoration: underline;
+  }
+
+  @each $color, $value in $theme-colors {
+    &-#{$color} {
+      @if $enable-gradients {
+        background: $value linear-gradient($value, mix($body-bg, $value, 15%)) repeat-x;
+      } @else {
+        background-color: $value;
+      }
+    }
+  }
+
+  &-light {
+    &,
+    a,
+    .alert-link {
+      color: $body-color;
+    }
+  }
+}
+
+.badge {
+  &.bg-light {
+    color: $dark;
+  }
+}
+
+// Containers
+
+.list-group {
+  font-size: $font-size-sm;
+}

assets/sass/_custom-vars.scss

@@ -0,0 +1,4 @@
+// custom-vars.scss
+// set scss variable defaults
+
+$grid-gutter-width: 15px;

assets/sass/_custom.scss

@@ -1,3 +1,5 @@
+// styles
+
 .pagination {
   display: flex;
   justify-content: center;

assets/sass/_litera.scss

@@ -0,0 +1,100 @@
+// Litera 5.1.3
+// Bootswatch
+
+$theme: "litera" !default;
+
+//
+// Color system
+//
+
+$white:    #fff !default;
+$gray-100: #f8f9fa !default;
+$gray-200: #e9ecef !default;
+$gray-300: #ddd !default;
+$gray-400: #ced4da !default;
+$gray-500: #adb5bd !default;
+$gray-600: #868e96 !default;
+$gray-700: #495057 !default;
+$gray-800: #343a40 !default;
+$gray-900: #212529 !default;
+$black:    #000 !default;
+
+$blue:    #4582ec !default;
+$indigo:  #6610f2 !default;
+$purple:  #6f42c1 !default;
+$pink:    #e83e8c !default;
+$red:     #d9534f !default;
+$orange:  #fd7e14 !default;
+$yellow:  #f0ad4e !default;
+$green:   #02b875 !default;
+$teal:    #20c997 !default;
+$cyan:    #17a2b8 !default;
+
+$primary:       $blue !default;
+$secondary:     $gray-500 !default;
+$success:       $green !default;
+$info:          $cyan !default;
+$warning:       $yellow !default;
+$danger:        $red !default;
+$light:         $gray-100 !default;
+$dark:          $gray-800 !default;
+
+$min-contrast-ratio:   1.85 !default;
+
+// Body
+
+$body-color:                $gray-800 !default;
+
+// Fonts
+
+// stylelint-disable value-keyword-case
+$font-family-sans-serif:      -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji" !default;
+$font-family-serif:           Georgia, Cambria, "Times New Roman", Times, serif !default;
+// stylelint-enable
+
+$font-size-base:              1.1rem !default;
+$headings-font-weight:        700 !default;
+
+// Tables
+
+$table-border-color:          rgba(0, 0, 0, .1) !default;
+
+$table-bg-scale:              0 !default;
+
+// Buttons
+
+$input-btn-padding-y:         .5rem !default;
+$input-btn-padding-x:         1.1rem !default;
+$btn-font-family:             $font-family-sans-serif !default;
+$btn-font-size:               .875rem !default;
+$btn-font-size-sm:            .688rem !default;
+
+$btn-border-radius:           1.078em !default;
+$btn-border-radius-lg:        2.688em !default;
+$btn-border-radius-sm:        .844em !default;
+
+// Forms
+
+$input-border-color:                    rgba(0, 0, 0, .1) !default;
+$input-group-addon-bg:                  $gray-200 !default !default;
+
+// Navbar
+
+$navbar-dark-color:                 rgba($white, .6) !default;
+$navbar-dark-hover-color:           $white !default;
+$navbar-light-hover-color:          $body-color !default;
+$navbar-light-active-color:         $body-color !default;
+
+// Tooltips
+
+$tooltip-font-size:                 11px !default;
+
+// Badges
+
+$badge-font-weight:                 400 !default;
+$badge-padding-y:                   .6em !default;
+$badge-padding-x:                   1.2em !default;
+
+// Alerts
+
+$alert-border-width:                0 !default;

assets/sass/_spacelab.scss

@@ -0,0 +1,64 @@
+// Spacelab 5.1.3
+// Bootswatch
+
+$theme: "spacelab" !default;
+
+//
+// Color system
+//
+
+$white:    #fff !default;
+$gray-100: #f8f9fa !default;
+$gray-200: #eee !default;
+$gray-300: #dee2e6 !default;
+$gray-400: #ced4da !default;
+$gray-500: #999 !default;
+$gray-600: #777 !default;
+$gray-700: #495057 !default;
+$gray-800: #333 !default;
+$gray-900: #2d2d2d !default;
+$black:    #000 !default;
+
+$blue:    #446e9b !default;
+$indigo:  #6610f2 !default;
+$purple:  #6f42c1 !default;
+$pink:    #e83e8c !default;
+$red:     #cd0200 !default;
+$orange:  #fd7e14 !default;
+$yellow:  #d47500 !default;
+$green:   #3cb521 !default;
+$teal:    #20c997 !default;
+$cyan:    #3399f3 !default;
+
+$primary:       $blue !default;
+$secondary:     $gray-500 !default;
+$success:       $green !default;
+$info:          $cyan !default;
+$warning:       $yellow !default;
+$danger:        $red !default;
+$light:         $gray-200 !default;
+$dark:          $gray-800 !default;
+
+$min-contrast-ratio:   2.65 !default;
+
+// Body
+
+$body-color:                $gray-600 !default;
+
+// Links
+
+$link-color:                $info !default;
+
+// Fonts
+
+// stylelint-disable-next-line value-keyword-case
+$font-family-sans-serif:      "Open Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol" !default;
+$headings-color:              $gray-900 !default;
+
+// Navbar
+
+$navbar-dark-color:                 rgba($white, .75) !default;
+$navbar-dark-hover-color:           $white !default;
+$navbar-light-color:                rgba($black, .4) !default;
+$navbar-light-hover-color:          $info !default;
+$navbar-light-active-color:         $info !default;

assets/sass/main.scss

@@ -1,8 +1,9 @@
 // Import partials from `sass_dir` (defaults to `_sass`)
 @import
-        "litera-soft",
+        "custom-vars",
-        "../../../node_modules/bootstrap/scss/bootstrap",
+        "litera",
-        "bootswatch",
+        "../../../common/bootstrap/scss/bootstrap",
+        "bootswatch-5",
         "custom",
         "syntax-tango"
 ;

layouts/_default/baseof.html

@@ -24,8 +24,8 @@
   </div>
   {{ partial "footer.html" . }}    
   <!--<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>-->
-  <script src="{{ .Site.BaseURL }}js/jquery.min.js"></script>
+  <!--<script src="{{ .Site.BaseURL }}js/jquery.min.js"></script>-->
-  <script src="{{ .Site.BaseURL }}js/bootstrap.min.js"></script>
+  <script src="{{ .Site.BaseURL }}js/bootstrap.bundle.min.js"></script>
   {{ block "appjs" . }} {{ end }}  
 </body>
 </html>

layouts/partials/footer.html

@@ -3,7 +3,7 @@
     <div class="row p10">
 
       {{ with .Site.Params.copyright }}
-        <div class="col-md-4 text-left">
+        <div class="col-md-4 text-start">
           <span class="fa fa-copyright"></span>
           <a target="_blank" class="text-decoration-none"
              href="{{.link}}">{{ .name }}</a>
@@ -16,7 +16,7 @@
         {{ end }}
       </div>
 
-      <ul class="col-md-4 text-right list-inline">
+      <ul class="col-md-4 text-end list-inline">
         {{with  .Site.Params.github }}
           <li class="social github list-inline-item">
             <a target="_blank" title="GitHub" href="{{.}}"><i class="fa fa-github-square"></i></a></li>

layouts/partials/sidebar.html

@@ -29,7 +29,7 @@
       <div class="card-body">
           {{ range . -}}
           {{- $page := $site.GetPage (printf "/topics/%s" .) -}}
-          <span class="badge badge-pill badge-secondary m-1">
+          <span class="badge rounded-pill bg-secondary m-1">
             <a href="{{ $page.Permalink }}">{{ $page.Title }}</a>
           </span>
           {{- end }}

layouts/taxonomy/list.html

@@ -23,7 +23,7 @@
             <p class="card-text">
             {{- i18n "child-topics" -}}:
             {{ range . -}}
-              <span class="badge badge-pill badge-secondary mr-1">
+              <span class="badge rounded-pill bg-secondary m-1">
                 <a href="{{ .Permalink }}">{{ .Title }}</a>
               </span>
             {{- end }}
@@ -42,7 +42,7 @@
         <div class="card-body">
           {{ range . -}}
             {{- $page := $site.GetPage (printf "/topics/%s" .) -}}
-            <span class="badge badge-pill badge-secondary mr-1 mb-1">
+            <span class="badge rounded-pill bg-secondary m-1">
               <a href="{{ $page.Permalink }}"
                  class="text-decoration-none">{{ $page.Title }}
               </a>

layouts/taxonomy/terms.html

@@ -20,7 +20,7 @@
         <a href="{{ .Page.Permalink }}" 
            class="list-group-item d-flex justify-content-between align-items-center text-decoration-none">
           {{ .Page.Title }}
-          <span class="badge badge-light badge-pill">{{ .Count }}</span>
+          <span class="badge rounded-pill bg-secondary">{{ .Count }}</span>
         </a>
       </div>
     </div>