update(css): added btn-spinner, refactored btn-primary class

assets/css/cart.css

@@ -396,21 +396,9 @@ body {
 
 /* CTA buttons */
 .btn-checkout {
-	display: flex;
-	align-items: center;
 	justify-content: center;
-	gap: var(--space-2);
-	background: var(--blue);
-	color: white;
-	border: none;
-	border-radius: var(--radius-md);
-	padding: var(--space-4) var(--space-6);
 	font-size: var(--text-xl);
-	font-weight: 700;
-	cursor: pointer;
-	font-family: inherit;
 	width: 100%;
-	transition: background 0.2s, transform 0.15s;
 }
 
 .btn-checkout:hover {
@@ -418,10 +406,6 @@ body {
 	transform: translateY(-0.0625rem);
 }
 
-.btn-checkout::after {
-	content: "→";
-}
-
 .btn-continue {
 	display: flex;
 	align-items: center;
@@ -445,10 +429,6 @@ body {
 	background: var(--blue-light);
 }
 
-.btn-continue::before {
-	content: "←";
-}
-
 .btn-clear {
 	display: flex;
 	align-items: center;