More visual controls for pane spacing and borders

[matiashoyld]

I would like more update-safe UI customization through config.toml.

My immediate pain point is multi-pane layouts: with borders off, panes blend together; with the current borders and gaps enabled, they still feel visually tight. I would like a way to add more breathing room while keeping pane boundaries clear.

The most useful controls would be:

• Width of the space between panes
• Padding between a pane border and its terminal content
• Optionally, border style and focused/unfocused border colors

The goal is a calmer, more organized layout without maintaining a custom Herdr build. Existing defaults could stay unchanged.

Would this fit Herdr’s visual direction?

[ClaudeBusiness1992]

Would love if this also covered the focused pane border width itself, not just spacing/padding.

Right now the only control is [ui] pane_borders = true/false — the focused border always uses the same "thick" glyph set with no way to go beyond that (see #688, which found the thick-vs-plain toggle already exists via the accent color path, but there's no way to make it visually heavier/thicker still). A pane_border_width (or a pane_border_style enum like plain / thick / double) alongside the pane_gap_width / pane_padding proposed here would round this out nicely — makes it much easier to make the active pane pop in a busy multi-agent layout.

[daun]

+1 for a padding setting. The current styling is a bit tight on large screens.

[magoz]

+1 for padding controls. Right now the main pane is too close to the sidebar