fix(trip): switch panel animation to max-height (grid-template-rows broken)

grid-template-rows: 0fr fails to fully collapse when the direct grid
child has overflow:hidden (creates a BFC that prevents 0-height).
max-height: 0 → 600px with overflow:hidden is simpler and reliable.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Vgmzx8VTTTmCskSpQtsLTr

themes/intotheeast/css/style.css

@@ -1210,22 +1210,19 @@ body::after {
 
 .trip-stats-block,
 .trip-cycling-block {
-    display: grid;
-    grid-template-rows: 0fr;
+    max-height: 0;
     overflow: hidden;
     margin-bottom: 0;
-    transition: grid-template-rows 0.35s ease, margin-bottom 0.35s ease;
+    transition: max-height 0.4s ease, margin-bottom 0.35s ease;
 }
 
 .trip-stats-block.is-open,
 .trip-cycling-block.is-open {
-    grid-template-rows: 1fr;
+    max-height: 600px;
     margin-bottom: var(--space-6);
 }
 
 .trip-panel-inner {
-    min-height: 0;
-    overflow: hidden;
     background: var(--color-canvas);
     border: 1px solid var(--color-border);
     border-radius: var(--radius-md);