docs: Add tiered focus visibility techniques to tmux pane border page

Stack multiple signals (color, background dimming, arrows, labels)
for progressively stronger pane focus indication in dense layouts.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: codekiln

pages/tmux___Q___How can I put a thick border around the focused pane%3F.md

@@ -32,6 +32,88 @@
 		- ### Requirements
 			- `heavy` and `double` border styles require UTF-8 support in your terminal
 			- If UTF-8 is not supported, tmux falls back to standard ACS line drawing
+	- ## Going Further: Making Focus Impossible to Miss
+		- Heavy borders alone are still pretty subtle, especially in dense multi-pane layouts. Thick lines alone don't change enough visual contrast.
+		- For **"impossible to miss" focus**, stack multiple signals:
+			- border weight
+			- strong color contrast
+			- background fill change
+			- title/status cue
+			- optionally dim *inactive* panes instead of highlighting the active one
+		- That last trick (dim others) is dramatically more legible.
+		- ### Tier 1 — Strong border + high-contrast color
+			- Much louder than basic `fg=green`:
+				- ~~~
+				  set -g pane-border-lines heavy
+				  
+				  # inactive = dark gray
+				  set -g pane-border-style fg=colour238
+				  
+				  # active = neon
+				  set -g pane-active-border-style fg=colour46,bold
+				  ~~~
+			- Bright green (`colour46`) or yellow (`colour226`) pops much harder than `green`.
+		- ### Tier 2 — Fill the entire active pane background (huge improvement)
+			- This is the first *actually obvious* solution.
+			- Change the **pane background**, not just the border:
+				- ~~~
+				  # dim inactive panes
+				  set -g window-style fg=colour245,bg=colour234
+				  
+				  # brighten active pane
+				  set -g window-active-style fg=colour255,bg=colour236
+				  ~~~
+			- Effect:
+				- everything else looks muted
+				- active pane looks "lit"
+			- This is far more perceptible than borders alone.
+			- Most people who try this never go back.
+		- ### Tier 3 — Add explicit focus markers (arrows)
+			- Adds directional cues:
+				- ~~~
+				  set -g pane-border-indicators both
+				  ~~~
+			- Gives arrows + color hint on the border edges.
+			- Helpful when panes are small.
+		- ### Tier 4 — Big "FOCUS" tag in the border (very obvious)
+			- tmux lets you show text in the active border:
+				- ~~~
+				  set -g pane-border-format "#{?pane_active,#[bold fg=black bg=colour46] ACTIVE #[default], }"
+				  ~~~
+			- You literally get `ACTIVE` on the focused pane's border. Zero ambiguity.
+		- ### Tier 5 — Extreme (best for dense layouts)
+			- Combine dimming + bright border + title:
+				- ~~~
+				  set -g pane-border-lines heavy
+				  set -g pane-border-style fg=colour238
+				  set -g pane-active-border-style fg=colour226,bold
+				  
+				  set -g window-style fg=colour245,bg=colour234
+				  set -g window-active-style fg=colour255,bg=colour236
+				  
+				  set -g pane-border-indicators both
+				  
+				  set -g pane-border-format "#{?pane_active,#[bold fg=black bg=colour226] ● ACTIVE #[default], }"
+				  ~~~
+			- This gives you:
+				- dim others
+				- bright yellow border
+				- arrows
+				- literal "● ACTIVE" label
+			- It's almost impossible to lose track of focus.
+		- ### Bonus: focus flash when switching panes
+			- A quick flash on selection for nice UX:
+				- ~~~
+				  bind -n C-h select-pane -L \; display-message "◀"
+				  bind -n C-j select-pane -D \; display-message "▼"
+				  bind -n C-k select-pane -U \; display-message "▲"
+				  bind -n C-l select-pane -R \; display-message "▶"
+				  ~~~
+			- Small directional feedback helps muscle memory.
+		- ### Practical recommendation
+			- For dense layouts (lots of panes, codespaces, tmux nested in browser): start with **Tier 2 + Tier 5 combo** (dim inactive + bright border + label).
+			- Borders alone just don't carry enough signal.
+			- That combo makes the active pane visually dominant without being garish.
 	- ## My Notes
 		- Add to `~/.tmux.conf` and reload with `tmux source-file ~/.tmux.conf`
 		- Or test live with `prefix + :` then type the set command