diff --git a/Dockerfile b/Dockerfile
index 5ebe438..ef8091e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,3 +1,4 @@
 FROM nginx:alpine
+COPY nginx-default.conf /etc/nginx/conf.d/default.conf
 COPY index.html /usr/share/nginx/html/index.html
 EXPOSE 80
diff --git a/index.html b/index.html
index 064585e..71dd9d6 100644
--- a/index.html
+++ b/index.html
@@ -1642,10 +1642,6 @@ function updateAll() {
   const phases = getPhaseSequence(effective);
   const totalMonths = estimateMonths(phases);
 
-  document.querySelectorAll('.referral-col').forEach(el => {
-    el.style.display = showRef ? '' : 'none';
-  });
-
   const yr1Cum = estimateYear1Cum(phases, commPct, giftLevel) * numPeople;
   const yr1PerPerson = estimateYear1Cum(phases, commPct, giftLevel);
   const totalEG = Math.round(phases.filter(k => k !== '3xL7')
@@ -1715,16 +1711,6 @@ ${numPeople > 0 ? `
   `;
   document.getElementById('summaryCards').innerHTML = summaryHtml;
 
-  // Toggle referral columns when no people in downline, but respect checkbox
-  const shouldShow = (numPeople > 0) && showRef;
-  for (const id of ['headerYourCut','headerCumulative','headerTimelineComm','headerTimelineCum']) {
-    const el = document.getElementById(id);
-    if (el) el.style.display = shouldShow ? '' : 'none';
-  }
-  for (const el of document.querySelectorAll('.referral-col')) {
-    el.style.display = shouldShow ? '' : 'none';
-  }
-
   let cumRunning = 0;
   let roiCum = 0;
   let roiHit = false;
@@ -1850,6 +1836,14 @@ ${numPeople > 0 ? `
   }
   document.getElementById('timelineBody').innerHTML = tRows;
 
+  // Referral-column visibility — must run AFTER both tables render, or the
+  // freshly built cells ignore the toggle while the headers obey it (the
+  // blank-headers-over-populated-columns bug, 2026-07-30).
+  const showRefCols = (numPeople > 0) && showRef;
+  for (const el of document.querySelectorAll('.referral-col')) {
+    el.style.display = showRefCols ? '' : 'none';
+  }
+
   const ctx2 = document.getElementById('timelineChart').getContext('2d');
   chart2 = new Chart(ctx2, {
     type: 'bar',
diff --git a/nginx-default.conf b/nginx-default.conf
new file mode 100644
index 0000000..58bbc98
--- /dev/null
+++ b/nginx-default.conf
@@ -0,0 +1,9 @@
+server {
+  listen 80;
+  root /usr/share/nginx/html;
+  index index.html;
+  # HTML must revalidate every load — deploys were invisible behind
+  # browser cache. Images/banners keep default caching.
+  location = /index.html { add_header Cache-Control "no-cache"; }
+  location = / { add_header Cache-Control "no-cache"; try_files /index.html =404; }
+}