fix(theme-classic): various fixes (#546)

* fix(theme-classic): vertically center items

* fix(classic-theme): extend bottom gradient to span full width

* fix(theme-classic): fix gradient on Safari

Author: sarahdayan

packages/autocomplete-theme-classic/src/theme.scss

@@ -503,6 +503,7 @@ body {
   align-items: center;
   border-radius: 3px;
   cursor: pointer;
+  display: grid;
   min-height: calc(var(--aa-spacing) * 2.5);
   padding: calc(var(--aa-spacing-half) / 2);
   // When the result is active
@@ -965,7 +966,7 @@ body {
   left: 0;
   pointer-events: none;
   position: absolute;
-  right: var(--aa-scrollbar-width);
+  right: 0;
   z-index: var(--aa-base-z-index);
 }
 
@@ -982,6 +983,8 @@ body {
     rgba(var(--aa-background-color-rgb), 0),
     rgba(var(--aa-background-color-rgb), 1)
   );
+  border-bottom-left-radius: calc(var(--aa-spacing) / 4);
+  border-bottom-right-radius: calc(var(--aa-spacing) / 4);
   bottom: 0;
 }