style(sidebar): refine membership cards

src/app/sidebar/components/voice-package-card.module.css

@@ -1,15 +1,19 @@
-/* 双层 background 实现 pink → orange 渐变描边 */
 .card {
-  background:
-    linear-gradient(#ffffff, #ffffff) padding-box,
+  background-image:
     linear-gradient(
-      135deg,
-      var(--color-voice-gradient-start, #ff6fa3),
-      var(--color-voice-gradient-end, #ff9a5a)
-    ) border-box;
-  border: var(--border-card, 1.5px) solid transparent;
-  border-radius: var(--radius-xl, 16px);
-  box-shadow: var(--shadow-card, 0 1px 3px rgba(0, 0, 0, 0.04));
+      180deg,
+      rgba(250, 208, 198, 0.57) 0%,
+      rgba(250, 176, 165, 0.57) 0%,
+      rgba(250, 143, 132, 0.57) 0%,
+      rgba(251, 176, 156, 0.57) 8%,
+      rgba(251, 208, 180, 0.57) 16%,
+      rgba(255, 255, 255, 0.57) 38%,
+      rgba(255, 255, 255, 0.57) 100%
+    ),
+    linear-gradient(#ffffff, #ffffff);
+  background-blend-mode: normal, normal;
+  border: solid 1px #fbbcb6;
+  border-radius: 21px;
   width: 100%;
   box-sizing: border-box;
   overflow: hidden;