diff --git a/sh/.config/sh/env b/sh/.config/sh/env
index c835c24..f333088 100644
--- a/sh/.config/sh/env
+++ b/sh/.config/sh/env
@@ -50,6 +50,8 @@ export LANG="en_US.UTF-8"
 export SHELL="${SHELL:-/bin/bash}"
 
 export TERM=xterm-256color
+# set env var to current shell background luminosity (used by vifm)
+. dark_bg
 
 if exist fzf; then
     export FZF_DEFAULT_OPTS="--bind 'tab:toggle+down,shift-tab:toggle+up,ctrl-g:top,ctrl-t:toggle-preview,ctrl-d:preview-half-page-down,ctrl-u:preview-half-page-up' --color=light -1 -m --delimiter :"
diff --git a/sh/.local/bin/dark_bg b/sh/.local/bin/dark_bg
new file mode 100755
index 0000000..380451a
--- /dev/null
+++ b/sh/.local/bin/dark_bg
@@ -0,0 +1,72 @@
+#!/usr/bin/env sh
+#
+# Determine if term background is dark or light.
+# Uses a couple different heuristics, most of them
+# from this:
+# https://unix.stackexchange.com/questions/245378/common-environment-variable-to-set-dark-or-light-terminal-background
+# unix exchange.
+#
+# If the background is dark, returns exit code 0 (true).
+# If the background is light, returns exit code 1 (false).
+# TODO implement alternative $COLORBFG method
+
+is_dark() {
+	IFS=/ read -r bg_r bg_g bg_b << EOF 
+${1:-"0000/0000/0000"}
+EOF
+	IFS=/ read -r fg_r fg_g fg_b << EOF 
+${2:-"ffff/ffff/ffff"}
+EOF
+    calc=$(echo "($bg_r+$bg_g+$bg_b)-($fg_r+$fg_g+$fg_b)" | tr '[:lower:]' '[:upper:]')
+    luminance=$(echo "ibase=16; $calc" | bc)
+	if [ "$luminance" -lt 0 ]; then
+		true
+	else
+		false
+	fi
+}
+
+orig_ssty=$(stty -g)
+stty raw -echo min 0 time 0
+printf '\e]11;?\a'
+sleep 0.01
+read -r answer
+bg="${answer#*;}"
+printf '\e]10;?\a'
+sleep 0.01
+read -r answer
+fg="${answer#*;}"
+
+stty "$orig_ssty"
+
+bg=$(echo "${bg}" | sed 's/.*\(rgb:[0-9a-f/]*\).*/\1/')
+fg=$(echo "${fg}" | sed 's/.*\(rgb:[0-9a-f/]*\).*/\1/')
+
+# from the amazing
+# https://stackoverflow.com/questions/2683279/how-to-detect-if-a-script-is-being-sourced
+# answer
+sourced=0
+if [ -n "$ZSH_VERSION" ]; then 
+  case $ZSH_EVAL_CONTEXT in *:file) sourced=1;; esac
+elif [ -n "$KSH_VERSION" ]; then
+  # shellcheck disable=SC2296
+  [ "$(cd -- "$(dirname -- "$0")" && pwd -P)/$(basename -- "$0")" != "$(cd -- "$(dirname -- "${.sh.file}")" && pwd -P)/$(basename -- "${.sh.file}")" ] && sourced=1
+elif [ -n "$BASH_VERSION" ]; then
+  (return 0 2>/dev/null) && sourced=1 
+else 
+  # Detects `sh` and `dash`; add additional shell filenames as needed.
+  case ${0##*/} in sh|-sh|dash|-dash) sourced=1;; esac
+fi
+
+is_dark "${bg#rgb:}" "${fg#rgb:}"
+outp="$?"
+
+if [ "$sourced" -eq 1 ]; then
+    if [ "$outp" -eq 0 ]; then
+        export TERM_DARK=true
+    else
+        export TERM_DARK=false
+    fi
+else
+    exit "$outp"
+fi
diff --git a/terminal/.config/vifm/scripts/vifm-default-viewer b/terminal/.config/vifm/scripts/vifm-default-viewer
index b4d0497..0ad47c6 100755
--- a/terminal/.config/vifm/scripts/vifm-default-viewer
+++ b/terminal/.config/vifm/scripts/vifm-default-viewer
@@ -21,5 +21,5 @@ charset=${info#*=}
 if [ "x$charset" == "xbinary" ]; then
     hexdump -e '"%08_ax: "' -e '8/1 "%02x " "  " 8/1 "%02x "' -e '" |" 16/1 "%_p"' -e '"\n"' -v -n $nbytes "$1"
 else
-    head -$nlines "$1" | enconv -g -L $language -x $encoding
+    head -$nlines "$1" | enconv -g -L $language -x $encoding | bat --color=always --style=plain
 fi
diff --git a/terminal/.config/vifm/vifmrc b/terminal/.config/vifm/vifmrc
index 688480a..cf813a8 100644
--- a/terminal/.config/vifm/vifmrc
+++ b/terminal/.config/vifm/vifmrc
@@ -552,7 +552,8 @@ filetype *.docx
             \ pandoc -s -t markdown %f | nvim,
             \ docx2txt %f - | nvim
 fileviewer *.docx
-            \ pandoc -s -t markdown %f,
+            \ [ "$TERM_DARK" = "true" ] && pandoc -s -t markdown %f |  glow --style=dark - || pandoc -s -t markdown %f | glow --style=light -,
+            \ pandoc -s -t markdown %f | bat --color=always --style=plain
             \ docx2txt %f -
 
 " TuDu files
@@ -569,6 +570,11 @@ fileviewer */
         \ exa --color always --tree -L2,
         \ tree -L 2,
 
+" markdown text
+fileviewer *.md
+        \ [ "$TERM_DARK" = "true" ] && glow --style=dark %c || glow --style=light %c,
+        \ bat --color=always --style=plain
+
 " use custom viewer script for rest
 fileviewer * vifm-default-viewer %c