Increase contrast in dark theme

Closes #194.

assets/stylesheets/global/variables-dark.scss

@@ -7,7 +7,7 @@ $headerHeight: 3rem;
 $sidebarWidth: 18rem;
 $sidebarMediumWidth: 16rem;
 
-$contentBackground: #2d2d2d;
+$contentBackground: #303030;
 
 $textColor: #c9c9c9;
 $textColorLight: #858585;
@@ -32,8 +32,8 @@ $highlightBackground: #3d4449;
 $linkColor: #fff;
 $linkColorHover: #fff;
 
-$headerBackground: #1e1e1e;
-$headerBorder: #1e1e1e;
+$headerBackground: #1c1c1c;
+$headerBorder: #1c1c1c;
 
 $sidebarBackground: #262626;
 $sidebarBorder: #262626;
@@ -44,30 +44,30 @@ $scrollbarColorHover: #888;
 $pathBackground: $headerBackground;
 $pathBorder: $headerBorder;
 
-$noticeBackground: #1e1e1e;
-$noticeBorder: #1e1e1e;
+$noticeBackground: #1c1c1c;
+$noticeBorder: #1c1c1c;
 
-$boxBackground: #1e1e1e;
-$boxBorder: #0a0a0a;
-$boxBorderLight: #171717;
-$boxHeaderBackground: #1e1e1e;
+$boxBackground: #262626;
+$boxBorder: #000;
+$boxBorderLight: #000;
+$boxHeaderBackground: #262626;
 
-$noteBackground: #3a3e31;
-$noteBorder: #1a1c17;
+$noteBackground: #3a4031;
+$noteBorder: #000;
 
-$noteGreenBackground: #283e2b;
-$noteGreenBorder: #111b13;
+$noteGreenBackground: #223e23;
+$noteGreenBorder: #000;
 
-$noteBlueBackground: #1f2f3e;
-$noteBlueBorder: #101922;
+$noteBlueBackground: #223546;
+$noteBlueBorder: #000;
 
-$noteOrangeBackground: #3e271d;
-$noteOrangeBorder: #1f1511;
+$noteOrangeBackground: #523121;
+$noteOrangeBorder: #000;
 
-$noteRedBackground: #3e1b1b;
-$noteRedBorder: #170808;
+$noteRedBackground: #5b1f22;
+$noteRedBorder: #000;
 
-$labelBackground: #3C3C3E;
+$labelBackground: #3c3c3e;
 
 $notifBackground: rgba(#000, .85);
 $notifColor: #fff;