细节修改

app/design/frontend/Joshine/breeze/Magento_Checkout/templates/onepage.phtml

@@ -758,10 +758,16 @@ script;
             $(window).scroll(function () {
                 var scrollTop = $(document).scrollTop(),
                     offsetTop = $('.checkout-container').offset().top,
-                    containerHeight = $('.checkout-container').height() - 20,
+                    containerHeight = $('.checkout-container').height()-20,
                     sidebarHeight = $('#opc-sidebar').height();
 
-                if (scrollTop > offsetTop && scrollTop <= containerHeight+offsetTop) {
+                if (scrollTop > offsetTop) {
+                    if (containerHeight + offsetTop - scrollTop > sidebarHeight) {
+                        $('#opc-sidebar').css('top', (scrollTop - offsetTop)+'px');
+                    } else {
+                        $('#opc-sidebar').css('top', (containerHeight - sidebarHeight)+'px');
+                    }
+                } else {
                     $('#opc-sidebar').css('top', '0');
                 }
             });

app/design/frontend/Joshine/breeze/web/css/_custom.less

@@ -2553,6 +2553,7 @@ tr.grand.totals {
 
 .cart-container .checkout-methods-items li:first-child{
   background-color: #000000;
+  height: 3.2rem;
 }
 .checkout.checkout-methods-items li .paypal.checkout{
   width: 100%;