diff --git a/frontend/js/db.js b/frontend/js/db.js
index b27b2a7..4cd1c2c 100644
--- a/frontend/js/db.js
+++ b/frontend/js/db.js
@@ -906,22 +906,8 @@ async function runMigrations() {
     console.log("[db.js] Seeded 5 serving units");
   }
 
-  // Seed product_units for eggs (one-time)
-  try {
-    const puCnt = await select("SELECT COUNT(*) as cnt FROM product_units");
-    if (puCnt[0].cnt === 0) {
-      const eggProducts = await select(
-        `SELECT id FROM products WHERE name_lower LIKE '%яйц%' AND name_lower LIKE '%кур%'`
-      );
-      for (const ep of eggProducts) {
-        await execute(
-          `INSERT OR IGNORE INTO product_units (product_id, unit_id, grams_per_unit)
-           VALUES (?1, 1, 60)`, [ep.id]
-        );
-      }
-      if (eggProducts.length > 0) console.log(`[db.js] Linked ${eggProducts.length} egg products`);
-    }
-  } catch (e) { console.error("[db.js] egg unit seeding error:", e); }
+  // product_units: user adds per-product unit mappings manually via UI.
+  // No auto-seeding — product names too varied for reliable matching.
 
   // --- Bikes table ---
   await execute(`CREATE TABLE IF NOT EXISTS bikes (
diff --git a/frontend/js/gps.js b/frontend/js/gps.js
index 16d891b..58b2138 100644
--- a/frontend/js/gps.js
+++ b/frontend/js/gps.js
@@ -67,12 +67,12 @@ GPS.computeStats = function(points, weightKg, opts) {
   const rho = 1.225;        // air density at sea level (kg/m^3)
   const efficiency = 0.25;  // human mechanical efficiency (~25%)
   const Crr = opts?.surfaceCrr ?? 0.006; // rolling resistance (mixed surface default)
-  const mTotal = (weightKg ?? 80) + (opts?.bikeWeightKg ?? 0);
+  const wKg = parseFloat(weightKg) || 80; // ensure numeric (profile stores strings)
+  const mTotal = wKg + (parseFloat(opts?.bikeWeightKg) || 0);
   const isBike = (opts?.activityType ?? "bike") === "bike";
 
   let totalKcal = 0;
-  // Basal metabolic rate per minute (MET=1 sitting, formula: MET * 3.5 * kg / 200)
-  const basalPerMin = (1.0 * 3.5 * (weightKg ?? 80)) / 200;
+  const basalPerMin = (1.0 * 3.5 * wKg) / 200;
 
   // Cadence tracking
   let totalPedalRevs = 0;
@@ -111,8 +111,8 @@ GPS.computeStats = function(points, weightKg, opts) {
       const rawAlt = sorted[i].altitude ?? sorted[i].altitude_gps_m ?? 0;
       const rawAltPrev = sorted[i-1].altitude ?? sorted[i-1].altitude_gps_m ?? 0;
       const altDiff = rawAlt - rawAltPrev;
-      const gradient = d > 2 ? altDiff / d : 0; // rise/run
-      const sinG = gradient; // for small angles sin ~= gradient
+      const gradient = d > 2 ? Math.max(-0.5, Math.min(0.5, altDiff / d)) : 0; // clamp to +-50%
+      const sinG = gradient;
       const cosG = Math.sqrt(1 - sinG * sinG);
 
       // Power required (watts): gravity + rolling resistance + aerodynamic drag
@@ -149,7 +149,7 @@ GPS.computeStats = function(points, weightKg, opts) {
       else if (speedKmh < 16) met = 12.5;  // fast running
       else met = 15.0;                      // sprint
 
-      totalKcal += (dt / 60) * (met * 3.5 * (weightKg ?? 80)) / 200;
+      totalKcal += (dt / 60) * (met * 3.5 * wKg) / 200;
     }
   }
 
diff --git a/frontend/js/main.js b/frontend/js/main.js
index 177e1de..531719b 100644
--- a/frontend/js/main.js
+++ b/frontend/js/main.js
@@ -607,11 +607,14 @@ async function renderStatsCharts(container, days, foodTotals, bmr) {
       const closeBtn = document.createElement("div");
       closeBtn.className = "chart-close-btn";
       closeBtn.innerHTML = "&#x2715;";
-      closeBtn.onclick = (e) => {
-        e.stopPropagation();
+      function collapseChart() {
         wrap.classList.remove("chart-full");
         closeBtn.remove();
-      };
+        window.removeEventListener("popstate", chartPopHandler);
+      }
+      closeBtn.onclick = (e) => { e.stopPropagation(); collapseChart(); history.back(); };
+      const chartPopHandler = () => { collapseChart(); };
+      window.addEventListener("popstate", chartPopHandler, { once: true });
       wrap.appendChild(closeBtn);
     };
   });
@@ -3218,6 +3221,14 @@ function esc(str) {
 window.addEventListener("popstate", (e) => {
   // If a modal is open, don't handle here (modal has its own handler)
   if (document.querySelector(".modal-overlay")) return;
+  // Chart fullscreen on screen (not in modal) — collapse it
+  const fsChart = document.querySelector(".chart-full");
+  if (fsChart) {
+    fsChart.classList.remove("chart-full");
+    const btn = fsChart.querySelector(".chart-close-btn");
+    if (btn) btn.remove();
+    return;
+  }
   // Stale modal/chart entries left after app restart — skip them
   if (e.state && (e.state.modal || e.state.chartFull)) {
     history.back();