viz: actually suppress rectangular focus on SVG paths (box-shadow culprit)

Previous fix targeted outline only, but the rectangular cyan box was the
box-shadow from the global :focus-visible rule: Chrome renders both
outline AND box-shadow on SVG <path> as the path's bounding-box
rectangle, ignoring the arc geometry.

Fix at source: change global :focus-visible to :focus-visible:not(path)
so the rule simply does not match SVG paths in the first place. Path
focus is now exclusively handled by the dedicated path[role="button"]
rule using stroke (which follows the arc shape).

Added !important on path outline/box-shadow override to defend against
any other selector that may target SVG paths in the future.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: quantbai

docs/style.css

@@ -155,22 +155,26 @@ input {
   border: 0;
 }
 
-/* Focus ring — WCAG 2.4.13 compliant */
-:focus-visible {
+/* Focus ring — WCAG 2.4.13 compliant.
+   Excludes <path> because Chrome renders both `outline` and `box-shadow` on
+   SVG <path> as the path's bounding-box rectangle, which ignores the arc
+   geometry of sunburst wedges. Paths get their own stroke-based focus ring
+   in the dedicated rule below — the stroke follows the path geometry. */
+:focus-visible:not(path) {
   outline: 2px solid var(--accent);
   outline-offset: 2px;
   box-shadow: 0 0 0 4px var(--focus-ring);
 }
 
-/* SVG paths (sunburst wedges): rectangular outline does not follow the arc
-   shape. Suppress browser default and use stroke as focus indicator — stroke
-   follows the path geometry, giving a curved focus ring that matches the
-   wedge. WCAG 2.4.13: 2.5px stroke change, 3:1 contrast vs unfocused state. */
-path[role="button"] { outline: none; }
+/* SVG path focus indicator (sunburst wedges) — stroke follows arc shape. */
+path[role="button"] {
+  outline: none !important;
+  box-shadow: none !important;
+}
 path[role="button"]:focus,
 path[role="button"]:focus-visible {
-  outline: none;
-  box-shadow: none;
+  outline: none !important;
+  box-shadow: none !important;
   stroke: var(--accent);
   stroke-width: 2.5;
 }