style(ui): calm renderer shell visuals

apps/ui/src/styles/chat.css

@@ -162,7 +162,6 @@
   border-color: rgba(148, 199, 232, 0.46);
   color: #106bbf;
   box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9), 0 12px 24px rgba(89, 150, 194, 0.12);
-  transform: translateY(-1px);
 }
 
 .conversation-shell .nav-item.active {
@@ -208,7 +207,6 @@
   border-color: rgba(103, 176, 230, 0.74);
   color: #075eaf;
   box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.92), 0 18px 30px rgba(76, 143, 193, 0.2);
-  transform: translateY(-1px);
 }
 
 .conversation-shell .conversation-new-session-plus {
@@ -362,11 +360,11 @@
 .conversation-shell .sidebar-session-list:hover::-webkit-scrollbar-thumb,
 .conversation-shell .sidebar-session-list:active::-webkit-scrollbar-thumb,
 .conversation-shell .sidebar-session-list:focus::-webkit-scrollbar-thumb {
-  background: rgba(139, 92, 246, 0.3);
+  background: rgba(96, 165, 250, 0.34);
 }
 
 .conversation-shell .sidebar-session-list::-webkit-scrollbar-thumb:hover {
-  background: rgba(139, 92, 246, 0.5);
+  background: rgba(37, 99, 235, 0.42);
 }
 
 .conversation-shell .expert-category-item {

apps/ui/src/styles/components.css

@@ -293,8 +293,7 @@
   padding: 0 2px;
   opacity: 0;
   pointer-events: none;
-  transform: translateY(-2px);
-  transition: opacity 150ms ease, transform 150ms ease;
+  transition: opacity 150ms ease;
 }
 
 .thinking-spinner {
@@ -864,7 +863,6 @@
 .message-card:focus-within .message-card-meta {
   pointer-events: auto;
   opacity: 1;
-  transform: translateY(0);
 }
 
 .message-action-delete:hover {
@@ -924,8 +922,8 @@
 }
 
 .composer-shell.dragging {
-  border-color: rgba(139, 92, 246, 0.36);
-  background: var(--color-primary-50);
+  border-color: rgba(37, 99, 235, 0.36);
+  background: #eff6ff;
 }
 
 .composer-skill-badge {
@@ -1144,7 +1142,7 @@
   gap: 8px;
 }
 .catalog-item.static { cursor: default; }
-.catalog-item:hover { transform: translateY(-1px); }
+.catalog-item:hover { transform: none; }
 .catalog-item.static:hover { transform: none; }
 
 .form-grid.single { grid-template-columns: 1fr; }

apps/ui/src/styles/shell.css

@@ -16,13 +16,9 @@
   display: grid;
   grid-template-rows: auto auto minmax(0, 1fr);
   gap: 18px;
-  background:
-    linear-gradient(180deg, rgba(167, 139, 250, 0.15), rgba(124, 58, 237, 0.1)),
-    rgba(255, 255, 255, 0.05);
-  backdrop-filter: blur(8px);
-  -webkit-backdrop-filter: blur(8px);
+  background: #eff6ff;
   border-right: 1px solid var(--color-border-light);
-  box-shadow: inset -1px 0 0 rgba(124, 58, 237, 0.2);
+  box-shadow: inset -1px 0 0 rgba(148, 163, 184, 0.22);
 }
 
 .nav-list,
@@ -74,8 +70,8 @@
 
 .nav-item.active {
   background: linear-gradient(135deg,
-    rgba(139, 92, 246, 0.12),
-    rgba(59, 130, 246, 0.08)
+    rgba(239, 246, 255, 0.92),
+    rgba(219, 234, 254, 0.72)
   );
   color: var(--color-primary-500);
   box-shadow: var(--shadow-sm);
@@ -83,7 +79,7 @@
 }
 
 .nav-item:hover:not(.active) {
-  background: rgba(139, 92, 246, 0.05);
+  background: rgba(239, 246, 255, 0.72);
 }
 
 .sidebar-top,
@@ -106,7 +102,7 @@
   overflow-y: auto;
   overflow-x: hidden;
   scrollbar-width: thin;
-  scrollbar-color: rgba(139, 92, 246, 0.3) transparent;
+  scrollbar-color: rgba(96, 165, 250, 0.34) transparent;
 }
 
 .sidebar-expert-scroll::-webkit-scrollbar {
@@ -119,13 +115,13 @@
 }
 
 .sidebar-expert-scroll::-webkit-scrollbar-thumb {
-  background: rgba(139, 92, 246, 0.3);
+  background: rgba(96, 165, 250, 0.34);
   border-radius: 2px;
   transition: background 0.2s ease;
 }
 
 .sidebar-expert-scroll::-webkit-scrollbar-thumb:hover {
-  background: rgba(139, 92, 246, 0.5);
+  background: rgba(37, 99, 235, 0.42);
 }
 
 .sidebar-section {
@@ -200,9 +196,8 @@
 }
 
 .expert-card:hover {
-  transform: translateY(-2px);
-  box-shadow: var(--shadow-lg);
-  border-color: rgba(139, 92, 246, 0.3);
+  box-shadow: var(--shadow-sm);
+  border-color: rgba(96, 165, 250, 0.34);
 }
 
 .expert-card.active {
@@ -210,8 +205,8 @@
   box-shadow: var(--shadow-xl);
   background: linear-gradient(
     180deg,
-    rgba(139, 92, 246, 0.06),
-    rgba(59, 130, 246, 0.04)
+    rgba(239, 246, 255, 0.86),
+    rgba(248, 250, 252, 0.94)
   );
 }
 
@@ -260,16 +255,14 @@
 .sidebar-session-card:hover {
   background: rgba(255, 255, 255, 0.99);
   box-shadow: var(--shadow-sm);
-  transform: translateY(-1px);
 }
 
 .sidebar-session-card.active {
-  border-color: rgba(139, 92, 246, 0.1);
+  border-color: rgba(96, 165, 250, 0.2);
   background: linear-gradient(
     135deg,
-    rgba(139, 92, 246, 0.04) 0%,
-    rgba(139, 92, 246, 0.025) 50%,
-    rgba(139, 92, 246, 0.01) 100%
+    rgba(239, 246, 255, 0.86) 0%,
+    rgba(248, 250, 252, 0.94) 100%
   );
   box-shadow: var(--shadow-card);
 }
@@ -293,7 +286,7 @@
 }
 
 .sidebar-session-main:hover {
-  background: rgba(139, 92, 246, 0.04);
+  background: rgba(239, 246, 255, 0.72);
 }
 
 .sidebar-session-close {