anchor-based zoom levels, week separators in chart, UI polish

wwwroot/style.css

@@ -119,7 +119,22 @@ header h1 { font-size: 1.1rem; font-weight: 600; color: var(--accent); }
 }
 
 .bar-in-chain { gap: 0; }
-.bar-spacer { width: 10px; min-width: 10px; flex: 0 0 10px; }
+.bar-spacer {
+  width: 12px; min-width: 12px; flex: 0 0 12px;
+  position: relative;
+  align-self: stretch;
+}
+.bar-spacer::before {
+  content: '';
+  position: absolute;
+  left: 50%;
+  top: 0;
+  bottom: 0;
+  width: 1px;
+  background: var(--muted);
+}
+#chart-labels .bar-spacer { display: none; }
+.bar-spacer.chain-spacer::before { display: none; }
 
 .bar {
   width: 100%;