diff --git a/frontend/js/labs/organic.js b/frontend/js/labs/organic.js
index dc23237..22e4673 100644
--- a/frontend/js/labs/organic.js
+++ b/frontend/js/labs/organic.js
@@ -1382,15 +1382,21 @@ class OrganicSim {
     const comp = this._qualCompound;
     const anim = this._qualAnim;
 
-    // draw multiple test tubes
+    // draw multiple test tubes — sized to fill the available height (bigger flasks)
     const tubes = rxn.compounds;
-    const tubeW = 56, tubeH = 150, gap = 20;
+    const badgePad = 48;   // room above tubes for the +/−/? badge
+    const labelPad = 62;   // room below tubes for the name + reagent labels
+    const tubeH = Math.max(190, Math.min(H - badgePad - labelPad, 340));
+    const tubeW = Math.round(tubeH * 0.46);
+    const gap   = Math.round(tubeW * 0.6);
     const totalW = tubes.length * (tubeW + gap) - gap;
-    let startX = (W - totalW) / 2;
+    const startX = (W - totalW) / 2;
+    // centre vertically, but never push the tubes so low they leave the viewport
+    let ty = badgePad + Math.max(0, (H - badgePad - labelPad - tubeH) / 2);
+    ty = Math.min(ty, 210);
 
     tubes.forEach((tube, i) => {
       const tx = startX + i * (tubeW + gap);
-      const ty = (H - tubeH) / 2 - 10;
       const isActive = comp && comp === tube;
       const progress = (isActive && anim) ? Math.min(anim.t / anim.maxT, 1) : 0;
 
@@ -1398,19 +1404,19 @@ class OrganicSim {
 
       // label
       ctx.fillStyle = isActive ? '#C9A0FF' : 'rgba(255,255,255,0.5)';
-      ctx.font = `${isActive ? '700' : '400'} 10px Manrope,sans-serif`;
+      ctx.font = `${isActive ? '700' : '400'} 11px Manrope,sans-serif`;
       ctx.textAlign = 'center';
       ctx.textBaseline = 'top';
-      const label = tube.name.length > 12 ? tube.name.substring(0,11)+'…' : tube.name;
-      ctx.fillText(label, tx + tubeW/2, ty + tubeH + 8);
+      const label = tube.name.length > 14 ? tube.name.substring(0,13)+'…' : tube.name;
+      ctx.fillText(label, tx + tubeW/2, ty + tubeH + 10);
     });
 
     // reagent label
     ctx.fillStyle = 'rgba(255,255,255,0.35)';
-    ctx.font = '11px Manrope,sans-serif';
+    ctx.font = '12px Manrope,sans-serif';
     ctx.textAlign = 'center';
     ctx.textBaseline = 'bottom';
-    ctx.fillText(`Реагент: ${rxn.reagent}`, W/2, H - 4);
+    ctx.fillText(`Реагент: ${rxn.reagent}`, W/2, Math.min(H - 6, ty + tubeH + 44));
   }
 
   _drawTestTube(ctx, x, y, w, h, rxn, comp, progress, isActive) {