Merge pull request 'fix(charts): make the national-average marker visible on both templates' (#99) from fix/chart-marker-contrast into main

Reviewed-on: #99

nextjs-app/components/SatsChart.module.css

@@ -48,13 +48,32 @@
    Each bar compares against its own benchmark (expected vs higher standard /
    greater depth), so the marker sits on the individual bar's track rather than
    as one line spanning both bars. */
+/*
+ * Knockout, not a colour.
+ *
+ * This marker was var(--brand) — the same value as .barExpected and
+ * .barExceeding, so wherever it crossed a bar it measured 1.00:1 and was not
+ * rendered distinguishably at all. It scored 5.47:1 only against the empty
+ * track, which means it was visible precisely when a school was BELOW the
+ * national average and vanished for every school at or above it.
+ *
+ * No single colour fixes this, because the marker's position is data-driven:
+ * it can land on the bar, on the empty track, or straddle the boundary. So it
+ * is drawn as a knockout — a light core carrying a dark edge. On the teal bar
+ * the core reads; on the pale track the edge reads. Both tokens flip with the
+ * theme, so the pairing holds in dark mode too.
+ *
+ * The edge is box-shadow rather than border so it costs no layout width and
+ * cannot shift the 50% translate.
+ */
 .natTick {
   position: absolute;
   top: -3px;
   bottom: -3px;
-  width: 2px;
+  width: 3px;
   transform: translateX(-50%);
-  background: var(--brand);
+  background: var(--bg-card);
+  box-shadow: 0 0 0 1px var(--text-primary);
   border-radius: 2px;
   z-index: 4;
   pointer-events: none;
@@ -63,13 +82,14 @@
 .natTick::before {
   content: '';
   position: absolute;
-  top: -3px;
+  top: -4px;
   left: 50%;
   transform: translateX(-50%);
-  width: 5px;
-  height: 5px;
+  width: 6px;
+  height: 6px;
   border-radius: 50%;
-  background: var(--brand);
+  background: var(--bg-card);
+  box-shadow: 0 0 0 1px var(--text-primary);
 }
 
 .barHeaderRight {
@@ -122,12 +142,24 @@
   transition: width 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94);
 }
 
+/*
+ * Expected and Exceeding were both var(--brand) — one colour for two series,
+ * distinguished only by which row you were looking at, while the legend
+ * claimed two.
+ *
+ * They are a sequential pair, not two categories: "exceeding" is a subset of
+ * the same cohort at a harder bar. So they take two steps of the same hue
+ * rather than two different hues, with the harder measure the more intense
+ * step. --brand-stronger is darker than --brand in the light theme and lighter
+ * in the dark one, which is the right direction in both: further from the
+ * ground.
+ */
 .barExpected {
   background: var(--brand);
 }
 
 .barExceeding {
-  background: var(--brand);
+  background: var(--brand-stronger);
 }
 
 .barLabel {

nextjs-app/components/SatsChart.tsx

@@ -143,17 +143,40 @@ export default function SatsChart({ subjects }: SatsChartProps) {
           <SubjectColumn key={subject.name} subject={subject} />
         ))}
       </div>
+      {/*
+        The legend describes what is drawn, which it previously did not.
+
+        Both data swatches were var(--status-above) — green — while the bars
+        they labelled were var(--brand) teal, and they were identical to each
+        other, so two different series shared one swatch. Worse, the only
+        swatch that matched the bar colour was the one labelled "National
+        average": anyone reading the chart by matching colours would conclude
+        the teal bars WERE the national average.
+
+        Each swatch now carries the exact value its bar carries, and the
+        national-average swatch mirrors the knockout marker rather than being
+        a flat colour, so it is recognisable as the thing on the chart.
+      */}
       <div className={styles.legend}>
         <div className={styles.legendItem}>
-          <div className={styles.legendSwatch} style={{ background: 'var(--status-above)' }} />
+          <div className={styles.legendSwatch} style={{ background: 'var(--brand)' }} />
           Expected standard
         </div>
         <div className={styles.legendItem}>
-          <div className={styles.legendSwatch} style={{ background: 'var(--status-above)' }} />
+          <div className={styles.legendSwatch} style={{ background: 'var(--brand-stronger)' }} />
           Exceeding / high score
         </div>
         <div className={styles.legendItem}>
-          <div className={styles.legendSwatch} style={{ background: 'var(--brand)', width: '3px', height: '12px', borderRadius: '2px' }} />
+          <div
+            className={styles.legendSwatch}
+            style={{
+              background: 'var(--bg-card)',
+              boxShadow: '0 0 0 1px var(--text-primary)',
+              width: '3px',
+              height: '12px',
+              borderRadius: '2px',
+            }}
+          />
           National average
         </div>
       </div>

nextjs-app/components/school/schoolSections.module.css

@@ -1807,12 +1807,23 @@
     border-radius: 4px 0 0 4px;
     transition: width 0.6s ease;
 }
+/*
+ * Knockout, for the same reason as .natTick in SatsChart.module.css: this was
+ * var(--brand), identical to .att8VizFill above it, so where the marker
+ * crossed the school's own bar it measured 1.00:1 — invisible for exactly the
+ * schools at or above the national average.
+ *
+ * A light core with a dark edge reads on the teal fill and on the pale track
+ * alike, and both tokens flip with the theme. Keep this in step with
+ * SatsChart's .natTick; they are the same marker on two templates.
+ */
 .att8VizNatLine {
     position: absolute;
     top: -4px;
     bottom: -4px;
-    width: 2px;
-    background: var(--brand);
+    width: 3px;
+    background: var(--bg-card);
+    box-shadow: 0 0 0 1px var(--text-primary);
     border-radius: 2px;
     z-index: 2;
 }