统一PC前端布局密度（05-28-pc-frontend-layout-unification）

client/src/pages/ReimbursementDetailPage.tsx

@@ -740,7 +740,7 @@ export function ReimbursementDetailPage() {
 
   if (!reimbursementId) {
     return (
-      <div className="card-std p-6">
+      <div className="card-std p-5">
         <p className="text-sm text-red-600">缺少 reimbursementId 参数。</p>
       </div>
     );
@@ -760,7 +760,7 @@ export function ReimbursementDetailPage() {
       : "加载报销详情失败";
 
     return (
-      <div className="card-std space-y-3 p-6">
+      <div className="card-std space-y-3 p-5">
         <p className="text-sm text-red-600">{message}</p>
         <Button asChild variant="secondary">
           <Link to="/reimbursements">返回报销列表</Link>
@@ -1230,7 +1230,7 @@ export function ReimbursementDetailPage() {
           </SectionPanel>
 
           <SectionPanel title="明细与票据">
-            <div className="space-y-6">
+            <div className="space-y-4">
               <div className="space-y-4" data-testid="reimbursement-items">
         <div className="flex flex-col gap-3 md:flex-row md:items-center md:justify-between">
           <div className="space-y-1">
@@ -1465,7 +1465,7 @@ export function ReimbursementDetailPage() {
           </SectionPanel>
 
           <SectionPanel title="预算与审核提示">
-            <div className="space-y-6">
+            <div className="space-y-4">
               {budgetHint ? (
                 <div className="detail-command-panel text-sm" data-testid="reimbursement-budget-hint">
                   <h3 className="text-base font-semibold text-zinc-900">预算提示</h3>