Add indent guide and line fold arrows

_rstudio-dark.scss

 	background-color: $ui-line-active-gutter;
 }
 .ace_fold {
-	background-color: $rlang-function;
-	border-color: $ui-foreground;
+	background-color: $ui-fold-arrows-background;
+	border-color: $ui-fold-arrows-color;
+}
+.ace_indent-guide{
+	border-right: 1px solid $ui-indent_guide;
 }
 .ace_active-line ~ .ace_selection.ace_start {
 	background-color: opacify($ui-line-active, 1);

nord-polar-night-aurora.scss

 // primary UI colors
 // $ui-background           : $nord0;
 $ui-background           : #262a33;
-$ui-foreground           : $nord5;
-$ui-code-chunk-background: $nord1;
+$ui-foreground           : $nord4;
+$ui-code-chunk-background: $nord0;
 $ui-selection            : transparentize($nord3, 0.6);
 $ui-cursor               : $nord9;
 $ui-margin-line          : lighten($ui-selection, 5%);
 $ui-gutter-background    : $ui-background;
 
 // less common UI colors
-$ui-line-active       : transparentize($nord2, 0.4);
-$ui-line-active-gutter: $ui-background;
-$ui-line-find         : $ui-selection;
-$ui-bracket           : darken($ui-foreground, 50%);
-$ui-invisible         : darken($ui-foreground, 50%);
-$ui-debug-background  : lighten($ui-background, 10%);
+$ui-line-active           : transparentize($nord2, 0.6);
+$ui-line-active-gutter    : $ui-background;
+$ui-line-find             : $ui-selection;
+$ui-bracket               : darken($ui-foreground, 50%);
+$ui-invisible             : $nord3;
+$ui-indent-guide          : $nord1;
+$ui-debug-background      : lighten($ui-background, 10%);
+$ui-fold-arrows-background: $nord11;
+$ui-fold-arrows-color     : $ui-foreground;
 
 // R language colors
 $rlang-comment  : transparentize($ui-foreground, 0.5);

oceanic-eighties.scss

 $ui-gutter-background    : $ui-background;
 
 // less common UI colors
-$ui-line-active       : darken($ui-background, 0.1);
-$ui-line-active-gutter: #1b3541;
-$ui-line-find         : #36444c;
-$ui-bracket           : #6a6a6a;
-$ui-invisible         : #99999960;
-$ui-debug-background  : lighten($ui-background, 10%);
+$ui-line-active           : darken($ui-background, 0.1);
+$ui-line-active-gutter    : #1b3541;
+$ui-line-find             : #36444c;
+$ui-bracket               : #6a6a6a;
+$ui-invisible             : #99999960;
+$ui-indent-guide          : $ui-invisible;
+$ui-debug-background      : lighten($ui-background, 10%);
+$ui-fold-arrows-background: #f2777a;
+$ui-fold-arrows-color     : $ui-foreground;
 
 // R language colors
 $rlang-comment  : #999;

rsthemes/nord-polar-night-aurora.rstheme

 /* rs-theme-is-dark: TRUE */
 .ace_gutter {
   background: #262a33;
-  color: rgba(229, 233, 240, 0.25);
+  color: rgba(216, 222, 233, 0.25);
 }
 
 .ace_print-margin {
 
 .ace_editor {
   background-color: #262a33;
-  color: #e5e9f0;
+  color: #d8dee9;
 }
 
 .rstudio-themes-flat.ace_editor_theme {
   background-color: #262a33;
-  color: #e5e9f0;
+  color: #d8dee9;
 }
 
 .rstudio-themes-flat.ace_editor_theme .profvis-flamegraph {
   background-color: #262a33;
-  color: #e5e9f0;
+  color: #d8dee9;
 }
 
 .rstudio-themes-flat .ace_editor_theme {
   background-color: #262a33;
-  color: #e5e9f0;
+  color: #d8dee9;
 }
 
 .rstudio-themes-flat.editor_dark.ace_editor_theme a {
 }
 
 .rstudio-themes-flat.rstudio-themes-dark-menus .ace_editor.ace_autocomplete .ace_marker-layer .ace_active-line {
-  background: rgba(229, 233, 240, 0.25);
+  background: rgba(216, 222, 233, 0.25);
   border: none;
 }
 
 .rstudio-themes-flat.rstudio-themes-dark-menus .ace_editor.ace_autocomplete .ace_marker-layer .ace_line-hover {
-  background: rgba(229, 233, 240, 0.25);
+  background: rgba(216, 222, 233, 0.25);
   border: none;
 }
 
 
 .ace_marker-layer .ace_bracket {
   margin: -1px 0 0 -1px;
-  border: 1px solid #4e6388;
+  border: 1px solid #46597c;
 }
 
 .ace_marker-layer .ace_active-line {
-  background: rgba(67, 76, 94, 0.6);
+  background: rgba(67, 76, 94, 0.4);
 }
 
 .ace_marker-layer .ace_selected-word {
 .ace_marker-layer .ace_foreign_line {
   position: absolute;
   z-index: -1;
-  background-color: #3b4252;
+  background-color: #2e3440;
 }
 
 .ace_marker-layer .ace_active_debug_line {
 }
 
 .ace_fold {
-  background-color: #88c0d0;
-  border-color: #e5e9f0;
+  background-color: #bf616a;
+  border-color: #d8dee9;
+}
+
+.ace_indent-guide {
+  border-right: 1px solid #3b4252;
 }
 
 .ace_active-line ~ .ace_selection.ace_start {
 
 .ace_keyword.ace_other.ace_unit {
   font-style: normal;
-  color: #ebcb8b;
+  color: #bf616a;
 }
 
 .ace_constant.ace_language {
 }
 
 .ace_constant.ace_numeric {
-  color: #ebcb8b;
+  color: #bf616a;
 }
 
 .ace_constant.ace_character {
-  color: #ebcb8b;
+  color: #bf616a;
 }
 
 .ace_constant.ace_other {
-  color: #e5e9f0;
+  color: #d8dee9;
 }
 
 .ace_support.ace_function {
 }
 
 .ace_support.ace_constant {
-  color: #ebcb8b;
+  color: #bf616a;
 }
 
 .ace_support.ace_class {
   font-style: italic;
-  color: #bf616a;
+  color: #ebcb8b;
 }
 
 .ace_support.ace_type {
-  color: #bf616a;
+  color: #ebcb8b;
 }
 
 .ace_paren.ace_keyword.ace_operator {
 }
 
 .ace_comment {
-  color: rgba(229, 233, 240, 0.5);
+  color: rgba(216, 222, 233, 0.5);
 }
 
 .ace_invisible {
-  color: #4e6388;
+  color: #4c566a;
 }
 
 .ace_variable {
 }
 
 .ace_variable.ace_parameter {
-  color: #ebcb8b;
+  color: #bf616a;
 }
 
 .ace_entity.ace_name.ace_function {
 .ace_bracket {
   margin: 0 !important;
   border: 0 !important;
-  background-color: #4e6388;
+  background-color: #46597c;
 }
 
 .ace_console_error {
 }
 
 .terminal {
-  background-color: #eceae8;
-  color: #b1a394;
+  background-color: #262a33;
+  color: #d8dee9;
   font-feature-settings: "liga" 0;
   position: relative;
   user-select: none;
 }
 
 .terminal.xterm-cursor-style-block.focus:not(.xterm-cursor-blink-on) .terminal-cursor {
-  background-color: #333;
-  color: #CCC;
+  background-color: #81a1c1;
+  color: #81a1c1;
 }
 
-.terminal.focus.xterm-cursor-style-bar:not(.xterm-cursor-blink-on) .terminal-cursor::before,
-.terminal.focus.xterm-cursor-style-underline:not(.xterm-cursor-blink-on) .terminal-cursor::before {
+.terminal.focus.xterm-cursor-style-bar:not(.xterm-cursor-blink-on) .terminal-cursor::before, .terminal.focus.xterm-cursor-style-underline:not(.xterm-cursor-blink-on) .terminal-cursor::before {
   content: '';
   position: absolute;
-  background-color: #333;
+  background-color: #262a33;
 }
 
 .terminal:not(.focus) .terminal-cursor {
-  outline: 1px solid #333;
+  outline: 1px solid #d8dee9;
   outline-offset: -1px;
 }
 
 .terminal .xterm-selection div {
   position: absolute;
-  background-color: #333;
+  background-color: rgba(76, 86, 106, 0.4);
 }
 
 .terminal .xterm-viewport {
-  background-color: #eceae8;
+  background-color: #262a33;
   overflow-y: scroll;
 }
 
 .xtermInvertColor {
-  color: #eceae8;
+  color: #d8dee9;
 }
 
 .xtermInvertBgColor {
-  background-color: #b1a394;
+  background-color: #262a33;
 }
 
 .xtermBold {

rsthemes/oceanic-eighties.rstheme

 }
 
 .ace_fold {
-  background-color: #69c;
+  background-color: #f2777a;
   border-color: #ccc;
 }
 
+.ace_indent-guide {
+  border-right: 1px solid #99999960;
+}
+
 .ace_active-line ~ .ace_selection.ace_start {
   background-color: #11232d;
 }
 }
 
 .terminal {
-  background-color: #eceae8;
-  color: #b1a394;
+  background-color: #11232d;
+  color: #ccc;
   font-feature-settings: "liga" 0;
   position: relative;
   user-select: none;
 }
 
 .terminal.xterm-cursor-style-block.focus:not(.xterm-cursor-blink-on) .terminal-cursor {
-  background-color: #333;
-  color: #CCC;
+  background-color: #e19938;
+  color: #e19938;
 }
 
-.terminal.focus.xterm-cursor-style-bar:not(.xterm-cursor-blink-on) .terminal-cursor::before,
-.terminal.focus.xterm-cursor-style-underline:not(.xterm-cursor-blink-on) .terminal-cursor::before {
+.terminal.focus.xterm-cursor-style-bar:not(.xterm-cursor-blink-on) .terminal-cursor::before, .terminal.focus.xterm-cursor-style-underline:not(.xterm-cursor-blink-on) .terminal-cursor::before {
   content: '';
   position: absolute;
-  background-color: #333;
+  background-color: #11232d;
 }
 
 .terminal:not(.focus) .terminal-cursor {
-  outline: 1px solid #333;
+  outline: 1px solid #ccc;
   outline-offset: -1px;
 }
 
 .terminal .xterm-selection div {
   position: absolute;
-  background-color: #333;
+  background-color: rgba(27, 53, 65, 0.4);
 }
 
 .terminal .xterm-viewport {
-  background-color: #eceae8;
+  background-color: #11232d;
   overflow-y: scroll;
 }
 
 .xtermInvertColor {
-  color: #eceae8;
+  color: #ccc;
 }
 
 .xtermInvertBgColor {
-  background-color: #b1a394;
+  background-color: #11232d;
 }
 
 .xtermBold {