fix(visual): 1:1 banner/hero/modal + strip non-zibll card chrome

Align banner s-desc caption/scale-height, hero search pill and -40px cards, modal colorful header/spring scale; remove white/pink card borders and hover lifts across mainline surfaces.

assets/css/frontend/sidebar.css

@@ -12,9 +12,9 @@
 /* Widget 通用 */
 .widget {
   background: var(--surface-1, #fff);
-  border-radius: var(--radius-lg, 10px);
+  border-radius: var(--main-radius, var(--radius, 8px));
   box-shadow: var(--shadow-sm);
-  border: 1px solid rgba(255, 255, 255, 0.55);
+  border: none;
   margin-bottom: 20px;
   overflow: hidden;
 }