diff --git a/lib/-ftb-fzf b/lib/-ftb-fzf
index 3741d22..0af2e7e 100755
--- a/lib/-ftb-fzf
+++ b/lib/-ftb-fzf
@@ -7,29 +7,24 @@ zmathfunc
 local tmp_dir=${TMPPREFIX:-/tmp/zsh}-fzf-tab-$USER
 [[ -d $tmp_dir ]] || command mkdir $tmp_dir
 
-local ftb_preview_init="
-zmodload zsh/mapfile
-local -a _ftb_compcap=(\"\${(@f)mapfile[$tmp_dir/compcap.$$]}\")
-local -a _ftb_groups=(\"\${(@f)mapfile[$tmp_dir/groups.$$]}\")
-local bs=\$'\2'
-# get description
-export desc=\${\${\"\$(<{f})\"%\$'\0'*}#*\$'\0'}
-# get ctxt for current completion
-local -A ctxt=(\"\${(@0)\${_ftb_compcap[(r)\${(b)desc}\$bs*]#*\$bs}}\")
-# get group
-if (( \$+ctxt[group] )); then
-  export group=\$_ftb_groups[\$ctxt[group]]
-fi
-# get original word
-export word=\${(Q)ctxt[word]}
-# get real path if it is file
-if (( \$+ctxt[realdir] )); then
-  export realpath=\${ctxt[realdir]}\$word
-fi
-$(typeset -p words)
-"
+local ftb_preview_init
+ftb_preview_init=$(<"$FZF_TAB_HOME/lib/-ftb-preview.tpl")
+
+# Inject resolved paths (these MUST refer to the correct pid used to create the files)
+local compcap_file="$tmp_dir/compcap.$$"
+local groups_file="$tmp_dir/groups.$$"
+
+ftb_preview_init=${ftb_preview_init//__FTB_COMPCAP__/${(q)compcap_file}}
+ftb_preview_init=${ftb_preview_init//__FTB_GROUPS__/${(q)groups_file}}
+
+# Inject the dump of 'words'
+ftb_preview_init=${ftb_preview_init//__FTB_WORDS_DUMP__/$(typeset -p words)}
+
+# command substitution strips all trailing newlines from the output
+ftb_preview_init+=$'\n'
+
 local default_binds=tab:down,btab:up,change:top,ctrl-space:toggle,bspace:backward-delete-char/eof,ctrl-h:backward-delete-char/eof
-local fzf_command fzf_flags fzf_preview debug_command tmp switch_group fzf_pad fzf_min_height binds
+local fzf_command fzf_flags fzf_preview debug_command tmp switch_group active_group_style fzf_pad fzf_min_height binds
 local ret=0
 
 -ftb-zstyle -s fzf-command fzf_command || fzf_command=fzf
@@ -41,12 +36,18 @@ local ret=0
 -ftb-zstyle -s fzf-pad fzf_pad || fzf_pad=2
 -ftb-zstyle -s fzf-min-height fzf_min_height || fzf_min_height=0
 -ftb-zstyle -b use-fzf-default-opts use_fzf_default_opts || use_fzf_default_opts="no"
+-ftb-zstyle -a active-group-style active_group_style || active_group_style=(bold)
 
 -ftb-zstyle -a debug-command debug_command && {
   ${(eX)debug_command} $fzf_flags
   return
 }
 
+local -a _active_style_lower=(${(L)active_group_style})
+local -a _active_style_valid=(${(M)_active_style_lower:#(bold|underline|none)})
+local -a _active_style_sorted=(${(ou)_active_style_valid})
+local normalized_active_group_style=${${(j:,:)_active_style_sorted}:-none}
+
 print -rl -- $_ftb_compcap > $tmp_dir/compcap.$$
 print -rl -- $_ftb_groups  > $tmp_dir/groups.$$
 print -r -- ${ftb_preview_init/{f}/\$1} > $tmp_dir/ftb_preview_init.$$
@@ -55,7 +56,7 @@ binds=${binds//{_FTB_INIT_}/. $tmp_dir/ftb_preview_init.$$ {f} $'\n'}
 
 local -i header_lines=$#_ftb_headers
 local -i lines=$(( $#_ftb_compcap + fzf_pad + header_lines ))
-local reload_command="$commands[zsh] -f $FZF_TAB_HOME/lib/ftb-switch-group $$ $header_lines $tmp_dir"
+local reload_command="$commands[zsh] -f $FZF_TAB_HOME/lib/ftb-switch-group $$ $header_lines $normalized_active_group_style $tmp_dir"
 
 # detect if we will use tmux popup
 local use_tmux_popup=0
@@ -87,6 +88,8 @@ if [[ "$use_fzf_default_opts" == "yes" ]]; then
   fzf_default_opts=$FZF_DEFAULT_OPTS
 fi
 
+local -a initial_command=(${(z)reload_command} 0)
+
 FZF_DEFAULT_OPTS=$fzf_default_opts SHELL=$ZSH_NAME ${(z)fzf_command} \
   --ansi \
   --bind=$binds \
@@ -102,8 +105,8 @@ FZF_DEFAULT_OPTS=$fzf_default_opts SHELL=$ZSH_NAME ${(z)fzf_command} \
   --print-query \
   --query=$_ftb_query \
   --tiebreak=begin \
-  ${fzf_preview:+--preview=${ftb_preview_init/{f}/'{f}'}$fzf_preview} \
-  $fzf_flags < $tmp_dir/completions.$$ || ret=$?
+  ${fzf_preview:+--preview=${ftb_preview_init}$fzf_preview} \
+  $fzf_flags < <($initial_command) || ret=$?
 
 if (( ! use_tmux_popup )); then
   echoti civis >/dev/tty 2>/dev/null
diff --git a/lib/-ftb-preview.tpl b/lib/-ftb-preview.tpl
new file mode 100755
index 0000000..4824854
--- /dev/null
+++ b/lib/-ftb-preview.tpl
@@ -0,0 +1,21 @@
+zmodload zsh/mapfile
+local -a _ftb_compcap=("${(@f)mapfile[__FTB_COMPCAP__]}")
+local -a _ftb_groups=("${(@f)mapfile[__FTB_GROUPS__]}")
+local bs=$'\2'
+
+# get description
+export desc=${${"$(<'{f}')"%$'\0'*}#*$'\0'}
+# get ctxt for current completion
+local -A ctxt=("${(@0)${_ftb_compcap[(r)${(b)desc}$bs*]#*$bs}}")
+# get group
+if (( $+ctxt[group] )); then
+  export group=$_ftb_groups[$ctxt[group]]
+fi
+# get original word
+export word=${(Q)ctxt[word]}
+# get real path if it is file
+if (( $+ctxt[realdir] )); then
+  export realpath=${ctxt[realdir]}$word
+fi
+__FTB_WORDS_DUMP__
+
diff --git a/lib/ftb-switch-group b/lib/ftb-switch-group
index 8d06956..9c4397e 100644
--- a/lib/ftb-switch-group
+++ b/lib/ftb-switch-group
@@ -4,35 +4,86 @@ emulate -L zsh -o extended_glob
 zmodload zsh/mapfile
 
 # receive arguments
-local pid=$1 header_lines=$2 tmp_dir=$3 offset=$@[-1]
+local pid=$1 header_lines=$2 active_group_style=$3 tmp_dir=$4 offset=$5
 
 # read completion list
 local -a list=(${(f)mapfile[$tmp_dir/completions.$pid]})
 
-# get total group count
+local grep_cmd=''
 if (( $#list > 10000 )); then
-  local -Ua total=(${(f)"$(print -l ${list:$header_lines} | grep -a -oP '^\x1b\[[0-9;]*m')"})
-else
-  local -Ua total=(${(M)${list:$header_lines}#$'\x1b['[0-9;]#*m})
+  local v
+  # Prefer GNU grep: grep first (Linux), then ggrep (macOS/Homebrew)
+  # Use $commands[...] so we get the resolved executable path (not an alias/function).
+  if (( ${+commands[grep]} )); then
+    v=$("$commands[grep]" --version 2>/dev/null)
+    [[ $v == *'(GNU grep)'* ]] && grep_cmd=$commands[grep]
+  fi
+
+  if [[ -z $grep_cmd && ${+commands[ggrep]} -eq 1 ]]; then
+    v=$("$commands[ggrep]" --version 2>/dev/null)
+    [[ $v == *'(GNU grep)'* ]] && grep_cmd=$commands[ggrep]
+  fi
 fi
 
-# get current group index, start from 2
-local current=2
-if [[ -f $tmp_dir/current-group.$pid ]]; then
-  current=$(( $(<$tmp_dir/current-group.$pid) + offset ))
+# --- group marker detection (fzf-tab groups) ---------------------------------
+# When groups exist, fzf-tab prefixes each entry with a group SGR like $'\e[94m'.
+# When no groups exist (often file lists), entries may start with $'\e[0m'
+# (reset for LS_COLORS). Treat that as "no groups".
+
+local -Ua group_sgr_prefixes
+if [[ -n $grep_cmd ]]; then
+  group_sgr_prefixes=(
+    ${(f)"$(
+      print -l -- ${list:$header_lines} | "$grep_cmd" -a -oP $'^\x1b\\[[0-9;]*m'
+    )"}
+  )
+else
+  group_sgr_prefixes=(${(M)${list:$header_lines}#$'\x1b['[0-9;]#*m})
 fi
-(( current > $#total )) && current=1
-(( current == 0 )) && current=$#total
-echo $current > $tmp_dir/current-group.$pid
+
+# if the only marker is reset, there are no real groups
+if (( $#group_sgr_prefixes == 1 )) && [[ $group_sgr_prefixes[1] == $'\e[0m' ]]; then
+  group_sgr_prefixes=()
+fi
+
+# --- current group index (persist across reloads) ----------------------------
+local current=1
+if (( $#group_sgr_prefixes > 0 )) && [[ -f $tmp_dir/current-group.$pid ]]; then
+  current=$(( $(<$tmp_dir/current-group.$pid) + offset ))
+  (( current > $#group_sgr_prefixes )) && current=1
+  (( current <= 0 )) && current=$#group_sgr_prefixes
+fi
+print -r -- $current > $tmp_dir/current-group.$pid
+
+# configure style of active header
+local sgr_on='' sgr_off=''
+case $active_group_style in
+  (bold)          sgr_on=$'\x1b[1m';    sgr_off=$'\x1b[22m' ;;
+  (underline)     sgr_on=$'\x1b[4m';    sgr_off=$'\x1b[24m' ;;
+  (bold,underline) sgr_on=$'\x1b[1;4m'; sgr_off=$'\x1b[22;24m' ;;
+  (none)          sgr_on='';            sgr_off='' ;;
+  (*)             sgr_on=$'\x1b[1m';    sgr_off=$'\x1b[22m' ;;  # fallback
+esac
+
+# The ANSI SGR code that marks every line in the currently selected group.
+local current_prefix=${group_sgr_prefixes[current]}
 
 # print headers
 if (( header_lines != 0 )); then
-  print -l ${list[1,header_lines]/${total[current]}/$'\x1b[1m'}
+  local -i i
+  local line
+  for i in {1..$header_lines}; do
+    line=$list[i]
+    if [[ $line == *$current_prefix* ]]; then
+      # Apply style only to the group label (up to the first ']'), then disable it
+      line=${line/$current_prefix(#b)([^]]##)\]/$current_prefix$sgr_on${match[1]}]$sgr_off}
+    fi
+    print -r $line
+  done
 fi
 
-# print current group
-if (( $#list > 10000 )); then
-  print -l ${list:$header_lines} | grep -a -F "${total[current]}"
+if [[ -n $grep_cmd ]]; then
+  print -rl -- ${list:$header_lines} | "$grep_cmd" -a -F -- "${group_sgr_prefixes[current]}"
 else
-  print -l ${(M)${list:$header_lines}:#${total[current]}*}
+  print -rl -- ${(M)${list:$header_lines}:#${group_sgr_prefixes[current]}*}
 fi