Add full dark mode support (#1079)

* Add full dark mode support

* Fix welcome, permissions, and quick start scrollbars

* Fix action popup dark mode on mobile

* Add theme to info page

* Reduce flashbang

* Move position of settingsDisplayController to not break things

* Fix dictionary import drag drop theming

* Make dark shadow color less bad

* Prepare themeController to avoid not being able to set browser theme

4 files changed, 97 insertions, 26 deletions

diff --git a/ext/css/action-popup.css b/ext/css/action-popup.css
index e88aa3ee..5b68396f 100644
--- a/ext/css/action-popup.css
+++ b/ext/css/action-popup.css
@@ -27,6 +27,30 @@
 
     --warning-color: #96751c;
     --warning-color-light: #edc75e;
+
+    --nav-button-background-image: linear-gradient(#f8f8f8, #e0e0e0);
+    --nav-button-border-color: #cccccc;
+    --nav-button-background-image-focus: linear-gradient(#e8e8e8, #d0d0d0);
+    --nav-button-border-color-focus: #aaaaaa;
+    --nav-button-background-image-active-focus: linear-gradient(#c8c8c8, #e0e0e0);
+    --nav-button-border-color-active-focus: #808080;
+    --nav-button-icon-bg: #333333;
+    --background-color: #f8f9fa;
+    --text-color: #333333;
+    --svg-filter: 0;
+}
+
+:root[data-theme=dark] {
+    --nav-button-background-image: linear-gradient(#464646, #444444);
+    --nav-button-border-color: #333333;
+    --nav-button-background-image-focus: linear-gradient(#171717, #2f2f2f);
+    --nav-button-border-color-focus: #555555;
+    --nav-button-background-image-active-focus: linear-gradient(#373737, #1f1f1f);
+    --nav-button-border-color-active-focus: #7f7f7f;
+    --nav-button-icon-bg: #fbfbfb;
+    --background-color: #1e1e1e;
+    --text-color: #cccccc;
+    --svg-filter: invert(100%);
 }
 
 body {
@@ -36,6 +60,7 @@ body {
     font-size: var(--font-size);
     width: max-content;
     height: max-content;
+    background-color: var(--background-color);
 }
 
 h3 {
@@ -44,7 +69,7 @@ h3 {
     font-weight: 500;
     line-height: 1.1;
     font-size: 24px;
-    color: inherit;
+    color: var(--text-color);
 }
 label {
     font-weight: normal;
@@ -98,7 +123,7 @@ label {
     margin: 0 -10px;
     padding: 0.5em 10px;
     cursor: pointer;
-    color: #333;
+    color: var(--text-color);
     text-decoration: none;
     background-color: transparent;
     transition: background-color 0.125s linear 0s;
@@ -109,7 +134,7 @@ label {
 }
 .link-group:hover,
 .link-group:active {
-    color: #333;
+    color: var(--text-color);
     text-decoration: none;
 }
 .link-group:hover>.link-group-label,
@@ -136,11 +161,11 @@ label {
     margin: 0;
     padding: 0;
 }
-.link-group-icon[data-icon=chevron] { background-image: url(/images/right-chevron.svg); }
-.link-group-icon[data-icon=cog] { background-image: url(/images/cog.svg); }
-.link-group-icon[data-icon=key] { background-image: url(/images/key.svg); }
-.link-group-icon[data-icon=magnifying-glass] { background-image: url(/images/magnifying-glass.svg); }
-.link-group-icon[data-icon=question-mark-circle] { background-image: url(/images/question-mark-circle.svg); }
+.link-group-icon[data-icon=chevron] { background-image: url(/images/right-chevron.svg); filter: var(--svg-filter); }
+.link-group-icon[data-icon=cog] { background-image: url(/images/cog.svg); filter: var(--svg-filter); }
+.link-group-icon[data-icon=key] { background-image: url(/images/key.svg); filter: var(--svg-filter); }
+.link-group-icon[data-icon=magnifying-glass] { background-image: url(/images/magnifying-glass.svg); filter: var(--svg-filter); }
+.link-group-icon[data-icon=question-mark-circle] { background-image: url(/images/question-mark-circle.svg); filter: var(--svg-filter); }
 
 .link-group-label {
     vertical-align: middle;
@@ -304,8 +329,8 @@ input[type=checkbox]~.toggle-group>.toggle-handle:active:focus {
     white-space: nowrap;
 }
 .nav-button {
-    background-image: linear-gradient(#f8f8f8, #e0e0e0);
-    border: 1px solid #cccccc;
+    background-image: var(--nav-button-background-image);
+    border: 1px solid var(--nav-button-border-color);
     margin: 0;
     padding: 2px 3px;
     cursor: pointer;
@@ -317,27 +342,27 @@ input[type=checkbox]~.toggle-group>.toggle-handle:active:focus {
 .nav-button:hover,
 .nav-button:focus {
     z-index: 1;
-    border-color: #aaaaaa;
-    background-image: linear-gradient(#e8e8e8, #d0d0d0);
+    border-color: var(--nav-button-border-color-focus);
+    background-image: var(--nav-button-background-image-focus);
     box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.15);
     outline: none;
 }
 .nav-button:focus:not(:focus-visible) {
-    background-image: linear-gradient(#f8f8f8, #e0e0e0);
-    border-color: #cccccc;
+    background-image: var(--nav-button-background-image);
+    border-color: var(--nav-button-border-color);
     box-shadow: none;
 }
 .nav-button:focus-visible {
     z-index: 1;
-    border-color: #aaaaaa;
-    background-image: linear-gradient(#e8e8e8, #d0d0d0);
+    border-color: var(--nav-button-border-color-focus);
+    background-image: var(--nav-button-background-image-focus);
     box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.15);
 }
 .nav-button:active,
 .nav-button:active:focus {
     z-index: 1;
-    border-color: #808080;
-    background-image: linear-gradient(#c8c8c8, #e0e0e0);
+    border-color: var(--nav-button-border-color-active-focus);
+    background-image: var(--nav-button-background-image-active-focus);
     box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.15);
 }
 .nav-button>.icon {
@@ -346,7 +371,7 @@ input[type=checkbox]~.toggle-group>.toggle-handle:active:focus {
     width: 16px;
     height: 16px;
     box-sizing: content-box;
-    background-color: #333333;
+    background-color: var(--nav-button-icon-bg);
 }
 .nav-button:first-child,
 .nav-button:first-child[hidden]+.nav-button {
diff --git a/ext/css/material.css b/ext/css/material.css
index 18c72621..00265586 100644
--- a/ext/css/material.css
+++ b/ext/css/material.css
@@ -136,7 +136,7 @@
     --background-color-light: #0a0a0a;
     --background-color-dark1: #333333;
 
-    --shadow-color: rgba(255, 255, 255, 0.185);
+    --shadow-color: rgba(105, 105, 105, 0.185);
     --shadow-color-off: rgba(255, 255, 255, 0);
     --shadow-color-light: rgba(255, 255, 255, 0.085);
 
diff --git a/ext/css/popup-preview.css b/ext/css/popup-preview.css
index 2f5a03a8..a72edc65 100644
--- a/ext/css/popup-preview.css
+++ b/ext/css/popup-preview.css
@@ -24,18 +24,23 @@
     --line-height: calc(var(--line-height-no-units) / var(--font-size-no-units));
 
     --animation-duration: 0s;
+
+    --example-text-color: #333333;
 }
 :root[data-loaded=true] {
     --animation-duration: 0.25s;
 }
 
+:root[data-theme=dark] {
+    --example-text-color: #d4d4d4;
+}
+
+
 html {
     transition: background-color var(--animation-duration) linear 0s, color var(--animation-duration) linear 0s;
     background-color: rgba(255, 255, 255, 0);
-    color: #333333;
 }
 html.dark {
-    color: #d4d4d4;
     background-color: #1e1e1e;
 }
 html,
@@ -92,7 +97,7 @@ body {
     margin: 0;
     padding: 0;
     outline: none;
-    color: inherit;
+    color: var(--example-text-color);
     background-color: transparent;
     white-space: pre;
     transition: background-color var(--animation-duration) linear 0s, border-color var(--animation-duration) linear 0s;
diff --git a/ext/css/settings.css b/ext/css/settings.css
index d23062b1..3c05906e 100644
--- a/ext/css/settings.css
+++ b/ext/css/settings.css
@@ -76,6 +76,15 @@
     --modal-padding-vertical: 0.625em;
     --modal-padding-vertical-half: calc(var(--modal-padding-vertical) * 0.5);
     --modal-button-spacing: 0.625em;
+
+    --scrollbar-thumb-color: #c1c1c1;
+    --scrollbar-track-color: #f1f1f1;
+    --scrollbar-inverse-thumb-color: #444444;
+    --scrollbar-inverse-track-color: #2f2f2f;
+
+    --dictionary-import-border-color: #cccccc;
+    --dictionary-import-border-color-hover: #bfd1ff;
+    --dictionary-import-hover-background-color: rgba(28, 116, 233, 0.05);
 }
 :root:not([data-loaded=true]) {
     --animation-duration: 0s;
@@ -83,6 +92,38 @@
 :root[data-theme=dark] {
     --separator-color1: #333333;
     --separator-color2: #222222;
+
+    --scrollbar-thumb-color: #444444;
+    --scrollbar-track-color: #2f2f2f;
+    --scrollbar-inverse-thumb-color: #c1c1c1;
+    --scrollbar-inverse-track-color: #f1f1f1;
+
+    --dictionary-import-border-color: #333333;
+    --dictionary-import-border-color-hover: #1c74e9;
+    --dictionary-import-hover-background-color: rgba(191, 209, 255, 0.05);
+}
+
+/* Scrollbars */
+:root:not([data-theme=light]) .scrollbar {
+    scrollbar-color: var(--scrollbar-thumb-color) var(--scrollbar-track-color);
+}
+:root:not([data-theme=light]) .scrollbar::-webkit-scrollbar {
+    width: auto;
+}
+:root:not([data-theme=light]) .scrollbar::-webkit-scrollbar-button {
+    height: 0;
+}
+:root:not([data-theme=light]) .scrollbar::-webkit-scrollbar-thumb {
+    background-color: var(--scrollbar-thumb-color);
+}
+:root:not([data-theme=light]) .scrollbar::-webkit-scrollbar-track {
+    background-color: var(--scrollbar-thumb-color);
+}
+:root:not([data-theme=light]) .scrollbar::-webkit-scrollbar-track-piece {
+    background-color: var(--scrollbar-track-color);
+}
+:root:not([data-theme=light]) .scrollbar::-webkit-scrollbar-corner {
+    background-color: var(--scrollbar-track-color);
 }
 
 
@@ -2377,7 +2418,7 @@ input[type=number].dictionary-priority {
 
 #dictionary-drop-file-zone {
     transition: background-color var(--animation-duration) ease-in-out, border var(--animation-duration) ease-in-out;
-    border: 2px dashed rgb(204, 204, 204);
+    border: 2px dashed var(--dictionary-import-border-color);
     border-radius: 5px;
     flex: auto;
     min-height: 20em;
@@ -2390,13 +2431,13 @@ input[type=number].dictionary-priority {
 }
 
 #dictionary-drop-file-zone:hover {
-    background-color: rgba(28, 116, 233, 0.05);
+    background-color: var(--dictionary-import-hover-background-color);
     border: 2px dashed var(--accent-color);
 }
 
 #dictionary-drop-file-zone.drag-over {
     border: 2px solid var(--accent-color);
-    background-color: rgb(191, 209, 255);
+    background-color: var(--dictionary-import-border-color-hover);
 }
 
 #dictionary-drag-drop-text {