refactor(web): migrate feature screens to design tokens + radius token (#49)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/vocab/vocabulary-list.tsx

@@ -45,20 +45,20 @@ export function VocabularyList() {
           </Button>
         </div>
         {create.isError && (
-          <p role="alert" className="text-xs text-red-600">
+          <p role="alert" className="text-xs text-destructive">
             {t("form.rejected")}
           </p>
         )}
       </form>
       <ul className="flex-1 overflow-auto">
         {isLoading && (
-          <li className="p-3 text-sm text-neutral-400">…</li>
+          <li className="p-3 text-sm text-muted-foreground">…</li>
         )}
         {isError && (
-          <li className="p-3 text-sm text-red-600">{t("vocab.loadError")}</li>
+          <li className="p-3 text-sm text-destructive">{t("vocab.loadError")}</li>
         )}
         {data?.length === 0 && (
-          <li className="p-3 text-sm text-neutral-500">{t("vocab.empty")}</li>
+          <li className="p-3 text-sm text-muted-foreground">{t("vocab.empty")}</li>
         )}
         {data?.map((v) => (
           <li key={v.id} className="flex items-center gap-1 border-b pr-2">
@@ -85,7 +85,7 @@ export function VocabularyList() {
                   {t("form.cancel")}
                 </Button>
                 {renameVocabulary.isError && (
-                  <p role="alert" className="text-xs text-red-600">
+                  <p role="alert" className="text-xs text-destructive">
                     {t("form.rejected")}
                   </p>
                 )}
@@ -95,7 +95,7 @@ export function VocabularyList() {
                 <NavLink
                   to={`/vocabularies/${v.id}`}
                   className={({ isActive }) =>
-                    `block flex-1 px-3 py-2 text-sm ${isActive ? "bg-indigo-50" : "hover:bg-neutral-50"}`
+                    `block flex-1 px-3 py-2 text-sm ${isActive ? "bg-primary/10" : "hover:bg-muted"}`
                   }
                 >
                   {v.key}