implement styling refactor + fixes

public/style.css

@@ -3999,7 +3999,7 @@ body[data-theme="beta-ai"] .persona-form .field {
     margin-top: -2px;
     background: linear-gradient(180deg, rgba(255, 255, 255, 0), var(--composer-bg) 18%);
     border: 1px solid var(--line);
-    border-radius: 10;
+    border-radius: 30px;
     box-shadow: none;
     backdrop-filter: blur(12px);
 }
@@ -4051,6 +4051,7 @@ body[data-theme="beta-ai"] .persona-form .field {
     background: var(--panel-elevated);
     border: 1px solid var(--line);
     border-radius: 28px;
+    overflow: hidden;
     box-shadow: 0 28px 80px rgba(0, 0, 0, 0.18);
 }
 
@@ -4071,9 +4072,10 @@ body[data-theme="beta-ai"] .persona-form .field {
 .chat-drawer-body {
     min-height: 0;
     overflow: auto;
-    padding-right: 10px;
+    overflow-x: hidden;
+    padding-inline: 2px 8px;
     gap: 16px;
-    scrollbar-gutter: stable;
+    scrollbar-gutter: stable both-edges;
 }
 
 .chat-drawer-section {