Enhance customization form with input for box selection and update styles for better usability

pricing.html

@@ -53,6 +53,8 @@
             <option>4:00 PM – 5:30 PM</option>
             <option>Custom timing (tell us below)</option>
           </select>
+          <label for="box">Your box</label>
+          <input id="box" name="box" type="text" placeholder="Choose a box above" readonly required />
           <label for="preferences">Meal preferences</label>
           <textarea id="preferences" name="preferences" rows="3" placeholder="Less spicy, no onion, add extra protein..."></textarea>
           <button class="button button-primary" type="submit">Send my preferences <span>↗</span></button>