💄 Fix light/dark themes for admin

src/objects/scss/admin/_admin_theme.scss

@@ -3,8 +3,15 @@ Generic admin styling overrides.
 
 DO NOT PUT ANY TARGET APP-SPECIFIC RULES HERE.
 */
+@use './themes/dark' as dark-theme;
+@use './themes/light' as light-theme;
+
 @import "./vars";
 
+@include light-theme.styles;
+@include dark-theme.styles;
+
+
 // override django CSS variables
 // see admin/static/admin/css/base.css for a reference
 :root {
@@ -131,22 +138,59 @@ div.breadcrumbs {
   font-weight: bold !important;
 }
 
+@mixin icon-override($iconUrl) {
+  background: none;
+  // display: inline-flex;
+  // align-items: center;
+  // padding-left: 0;
+  color: var(--body-fg);
+  position: relative;
+
+  // need to use pseudo element, otherwise the text in the same element is not visible
+  // because of the mask clipping
+  &:before {
+    display: block;
+    content: '';
+    position: absolute;
+    left: 0;
+    top: 0;
+    width: 14px;
+    height: 14px;
+    margin-right: 2px;
+    background: var(--body-fg) !important;
+    color: var(--body-fg);
+    mask-image: url($iconUrl);
+    mask-repeat: no-repeat;
+    mask-size: 14px 14px;
+    mask-position: 0px 0px;
+  }
+}
+
 /* Icons */
 .addlink {
-  background: url("../img/admin/plus-square-regular.svg") 0 0/14px 14px no-repeat;
+  @include icon-override('../img/admin/plus-square-regular.svg');
 }
+
+.object-tools a.addlink {
+  &:before {
+    display: none;
+  }
+}
+
 .changelink,
 .inlinechangelink {
-  background: url("../img/admin/edit-regular.svg") 0 0/14px 14px no-repeat;
+  @include icon-override('../img/admin/edit-regular.svg');
 }
 .deletelink {
-  background: url("../img/admin/trash-alt-regular.svg") 0 0/14px 14px no-repeat;
+  background: url('../img/admin/trash-alt-regular.svg') 0 0/14px 14px no-repeat;
 }
 .datetimeshortcuts .clock-icon {
-  background: url("../img/admin/clock-regular.svg") 0 0/14px 14px no-repeat !important;
+  @include icon-override('../img/admin/clock-regular.svg');
+  background: none !important;
 }
 .datetimeshortcuts .date-icon {
-  background: url("../img/admin/calendar-alt-regular.svg") 0 0/14px 14px no-repeat !important;
+  @include icon-override('../img/admin/calendar-alt-regular.svg');
+  background: none !important;
 }
 
 /**

src/objects/scss/admin/_app_overrides.scss

@@ -36,7 +36,7 @@ $djai-border-width: 8px;
   width: 100%;
 
   /* Added to attach to body/breadcrumbs */
-  border-bottom: $djai-border-width solid $color_secondary;
+  border-bottom: var(--oz-djai-border-bottom-width) solid var(--oz-djai-border-bottom-color);
 
   & &__drop {
     min-width: 250px !important;
@@ -70,6 +70,9 @@ $djai-border-width: 8px;
       }
     }
   }
+  @at-root body.login #header {
+    padding-bottom: 15px !important;
+  }
 }
 
 // TODO: check environment banner

src/objects/scss/admin/_vars.scss

@@ -1,28 +1,28 @@
 /* Colors */
-$color-primary: #04a5bb;
-$color-primary-dark: #017092;
-$color-primary-light: #c3eaef;
+$color_primary: #04a5bb;
+$color_primary_dark: #017092;
+$color_primary_light: #c3eaef;
 
-$color-secondary: #f3f3f3;
-$color-secondary-dark: #ddd;
-$color-secondary-light: #fff;
+$color_secondary: #f3f3f3;
+$color_secondary_dark: #ddd;
+$color_secondary_light: #fff;
 
-$color-link: #017092;
-$color-link-hover: #051f31;
+$color_link: #017092;
+$color_link_hover: #051f31;
 
-$color-darkest: #000;
-$color-dark: #333;
-$color-lightest: #fff;
+$color_darkest: #000;
+$color_dark: #333;
+$color_lightest: #fff;
 
-$color-error: #ba2121; // default django admin color
+$color_error: #ba2121; // default django admin color
 
-$color-tooltip-background: #fffeaa;
-$color-tooltip-border: #f7f071;
-$color-tooltip-text: #000;
+$color_tooltip_background: #fffeaa;
+$color_tooltip_border: #f7f071;
+$color_tooltip_text: #000;
 
 /* Dimensions */
-$input-field-size: 20em; // django-original: 20em;
+$input_field_size: 20em; // django-original: 20em;
 
 /* Responsive breakpoints used int the Django admin */
-$breakpoint-tablet: 768px;
-$breakpoint-laptop: 1025px;
+$breakpoint_tablet: 768px;
+$breakpoint_laptop: 1025px;

src/objects/scss/admin/themes/_dark.scss

@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: EUPL-1.2 */
+/* Copyright (C) 2025 Dimpact */
+/**
+ * Dark theme implementation.
+ *
+ * Use this as:
+ *
+ *   @use './themes/dark' as dark-theme;
+ *
+ *   @include dark-theme.styles;
+ */
+
+/**
+ * Define the CSS properties overriding default admin theme.
+ */
+@mixin variables {
+  --primary: #037383 !important;
+  --secondary: #037383 !important;
+
+  --breadcrumbs-fg: #2fc0ec;
+  --breadcrumbs-link-hover: #888;
+  --breadcrumbs-bg: #333;
+
+  --link-fg: #04a5bb;
+  --link-hover-color: #b2cddf;
+
+  --hairline-color: #686868;
+
+  --button-hover-bg: #04a5bb;
+  --default-button-bg: #04a5bb;
+  --default-button-hover-bg: #888;
+}
+
+@mixin djai-variables {
+
+  // use a more specific selector so that the dark theme overrides the default,
+  // less specific selector.
+  .djai-dropdown-menu {
+    --djai-tab-bg--hover: #04a5bb;
+    --djai-tab-fg--active: #fff;
+    --djai-dropdown-bg--hover: #04a5bb;
+
+    --oz-djai-border-bottom-color: #333;
+  }
+}
+
+@mixin bootstrap {
+
+  .btn,
+  .btn:hover {
+    color: var(--body-fg);
+  }
+
+  pre {
+    color: var(--body-fg);
+  }
+}
+
+
+/**
+   * Aggregate the bits and pieces to define the dark theme style rules.
+   */
+@mixin styles {
+
+  // Include the relevant variables
+  @media (prefers-color-scheme: dark) {
+
+    // This either gets overridden by the more specific light theme selector, or applies
+    // in auto mode through the media query.
+    :root {
+      @include variables;
+    }
+
+    // only apply based on browser preferences if the theme is not explicitly set to
+    // light or dark
+    html[data-theme='auto'] {
+      @include variables;
+      @include djai-variables;
+      @include bootstrap;
+    }
+  }
+
+  // explicit dark-mode -> apply all relevant styles
+  html[data-theme='dark'] {
+    @include variables;
+    @include djai-variables;
+    @include bootstrap;
+  }
+}

src/objects/scss/admin/themes/_light.scss

@@ -0,0 +1,84 @@
+/* SPDX-License-Identifier: EUPL-1.2 */
+/* Copyright (C) 2025 Dimpact */
+/**
+ * Light/default theme implementation.
+ *
+ * Use this as:
+ *
+ *   @use './themes/light' as light-theme;
+ *
+ *   @include light-theme.styles;
+ */
+
+/**
+ * Define the CSS properties overriding default admin theme.
+ *
+ * @todo - check if the !important's are still needed?
+ *
+ * See `admin/static/admin/css/base.css` for a reference of available variables.
+ */
+@mixin variables {
+  --primary: #04a5bb !important;
+  --accent: #f3f3f3;
+  --secondary: #04a5bb !important;
+  --primary-fg: #fff;
+
+  --header-color: #fff;
+
+  --breadcrumbs-fg: #04a5bb;
+  --breadcrumbs-link-fg: var(--body-fg);
+  --breadcrumbs-link-hover: #000; // not in the core django vars
+  --breadcrumbs-bg: #f3f3f3;
+
+  --link-fg: #017092;
+  --link-hover-color: #051f31;
+  --link-selected-fg: #5b80b2;
+
+  // #748 client requested increased contrast for form-row borders
+  // here we override a django admin style
+  --hairline-color: #e5e5e5;
+
+  // --button-bg: var(--primary);
+  --button-fg: #fff;
+  --button-hover-bg: #017092;
+  --default-button-bg: #017092;
+  --default-button-hover-bg: #000;
+  --close-button-bg: #888;
+  --close-button-hover-bg: #333;
+
+  --object-tools-bg: #888;
+  --object-tools-hover-bg: #333;
+}
+
+@mixin djai-variables {
+  --djai-tab-bg: var(--primary); // no fallback to default admin vars
+  --djai-tab-bg--active: var(--breadcrumbs-bg);
+  --djai-tab-bg--hover: #017092;
+  --djai-tab-fg--active: var(--secondary);
+  --djai-dropdown-bg--active: #017092;
+  --djai-dropdown-bg--hover: #017092;
+
+  // custom properties
+  --oz-djai-border-bottom-width: 8px;
+  --oz-djai-border-bottom-color: #f3f3f3;
+}
+
+/**
+   * Aggregate the bits and pieces to define the light theme style rules.
+   *
+   * The light theme styles are not guarded by a media query to make sure they're the
+   * default that is applied.
+   */
+@mixin styles {
+
+  html[data-theme='light'],
+  :root {
+    @include variables;
+  }
+
+  // generic selector to be more specific than the library itself, but less specific
+  // than the dark theme styles
+  body {
+    @include djai-variables;
+  }
+}

src/objects/templates/admin/base_site.html

@@ -13,6 +13,10 @@
 
 {% block branding %}
     <h1 id="site-name"><a href="{% url 'admin:index' %}">{{ settings.PROJECT_NAME }} {% trans 'Administration' %}</a></h1>
+
+    {% if user.is_anonymous %}
+      {% include "admin/color_theme_toggle.html" %}
+    {% endif %}
 {% endblock %}
 
 {% block welcome-msg %}
@@ -35,6 +39,8 @@ <h1 id="site-name"><a href="{% url 'admin:index' %}">{{ settings.PROJECT_NAME }}
         {% csrf_token %}
         <button type="submit">{% trans 'Log out' %}</button>        
     </form>
+
+    {% include "admin/color_theme_toggle.html" %}
 {% endblock %}
 
 {% block nav-global %}{% endblock %}