redraw gym icons as squat rack/bench/barbell pictograms, rebalance quick tiles

agents.md

@@ -194,13 +194,15 @@ Themes: `web` = default frosted-glass website (sidebar + content, light/dark),
   `.web-section-head` (the eyebrow + `.web-section-title`) and `.web-tile-title`
   ("Right now" / "Gym PRs"). Desktop keeps the left-aligned headings.
 - The gym PR icons (`.gym-icon--squat` / `--bench` / `--deadlift`) are **pure
-  CSS barbells**, not SVGs: a bar (`::before`) plus plates drawn as layered
-  `linear-gradient` backgrounds on `::after`, all in `currentColor` so they
-  adapt to light/dark and the desktop app surface. More plates per side = a
-  heavier lift (bench 1, squat 2, deadlift 3). Don't swap them back to images.
-- `.web-quick` is top-aligned (`align-items: start`) so the shorter "Right now"
-  tile isn't stretched to the Gym tile's height (it used to leave a big empty
-  gap under the text).
+  CSS pictograms**, not SVGs: each is drawn as layered solid gradients on the
+  element's `background` in `currentColor` (one rectangle per background layer),
+  so they adapt to light/dark and the desktop app surface. Squat = a squat rack
+  with a racked barbell, bench = a bench press, deadlift = a loaded barbell.
+  Don't swap them back to images.
+- `.web-quick` keeps equal-height tiles (`align-items: stretch`, symmetric with
+  the taller Gym tile); the shorter "Right now" paragraph centres itself
+  vertically via `margin-block: auto` so it isn't stranded at the top with a
+  big gap under it.
 - Under `max-width: 640px` the year-grid heatmap (`.heatmap-container`) and its
   legend/hover row (`.heatmap-status-row`) are `display: none` — the grid is
   unreadable at phone widths. The contribution total and the commit history