Add standards legend to offset order page with proper positioning

- Move StandardsLegend from calculator input page to OffsetOrder page
- Position after project cards and before offset amount slider
- Update Wren certification link to https://www.wren.co/certification
- Add vertical spacing (mb-8) below the dropdown for better layout

components/CalculatorClient.tsx

@@ -4,7 +4,6 @@ import { useState } from 'react';
 import { TripCalculator } from '../src/components/TripCalculator';
 import { QRCalculatorLoader } from '../src/components/QRCalculatorLoader';
 import { OffsetOrder } from '../src/components/OffsetOrder';
-import { StandardsLegend } from './StandardsLegend';
 import { useHasQRData } from '../src/hooks/useQRDecoder';
 import type { VesselData } from '../src/types';
 
@@ -74,11 +73,6 @@ export function CalculatorClient() {
             onOffsetClick={handleOffsetClick}
           />
         )}
-
-        {/* Standards Legend - Learn about Wren's offset standards */}
-        <div className="w-full">
-          <StandardsLegend />
-        </div>
       </div>
     </div>
   );

components/StandardsLegend.tsx

@@ -7,7 +7,7 @@ export function StandardsLegend() {
   const [isExpanded, setIsExpanded] = useState(false);
 
   return (
-    <div className="mt-8 bg-gradient-to-br from-blue-50 to-cyan-50 rounded-2xl p-6 border border-blue-200 print:hidden">
+    <div className="mt-8 mb-8 bg-gradient-to-br from-blue-50 to-cyan-50 rounded-2xl p-6 border border-blue-200 print:hidden">
       {/* Header */}
       <button
         onClick={() => setIsExpanded(!isExpanded)}
@@ -145,7 +145,7 @@ export function StandardsLegend() {
           {/* Learn More */}
           <div className="text-center">
             <a
-              href="https://www.wren.co/certification-standards"
+              href="https://www.wren.co/certification"
               target="_blank"
               rel="noopener noreferrer"
               className="inline-flex items-center gap-2 text-sm font-medium text-blue-600 hover:text-blue-700 hover:underline"

src/components/OffsetOrder.tsx

@@ -15,6 +15,7 @@ import { PortfolioDonutChart } from './PortfolioDonutChart';
 import { getProjectColor } from '../utils/portfolioColors';
 import { CertificationBadge } from './CertificationBadge';
 import { useCalculatorState } from '../hooks/useCalculatorState';
+import { StandardsLegend } from '../../components/StandardsLegend';
 
 interface Props {
   tons: number;
@@ -464,6 +465,9 @@ export function OffsetOrder({ tons, monetaryAmount, onBack, calculatorType }: Pr
             </motion.div>
           </div>
 
+          {/* Standards Legend - Learn about Wren's certification standards */}
+          <StandardsLegend />
+
           {/* Offset Percentage Slider */}
           {!monetaryAmount && (
             <motion.div