fix: 优化后台工单工作区布局

frontend/src/admin/AdminLayout.jsx

@@ -304,7 +304,7 @@ export default function AdminLayout() {
         )}
       </Box>
 
-      <Box component="main" sx={{ flexGrow: 1, p: { xs: 2, md: 3 }, minWidth: 0 }}>
+      <Box component="main" sx={{ flex: '1 1 auto', width: { xs: '100%', md: 'calc(100vw - 240px)' }, maxWidth: { xs: '100%', md: 'calc(100vw - 240px)' }, boxSizing: 'border-box', p: { xs: 2, md: 3 }, minWidth: 0, overflowX: 'hidden' }}>
         {/* AppBar 占位：桌面 64 / 移动 56 + 搜索行 48 */}
         <Box sx={{ height: isMobile ? 104 : 64 }} />
         <Outlet />

frontend/src/admin/pages/TicketManage.jsx

@@ -146,13 +146,13 @@ export default function TicketManage() {
   ], [stats, total]);
 
   return (
-    <Box component="main" aria-labelledby="ticket-page-title">
+    <Box component="main" className="ticket-workspace" aria-labelledby="ticket-page-title">
       <Stack direction="row" alignItems="center" justifyContent="space-between" sx={{ mb: 2 }}>
         <Box><Typography id="ticket-page-title" variant="h5" component="h1">工单管理</Typography><Typography variant="body2" color="text.secondary">集中处理论坛和站内问题反馈</Typography></Box>
         <IconButton aria-label="刷新工单" title="刷新" onClick={refresh} disabled={loading || saving}><RefreshIcon /></IconButton>
       </Stack>
 
-      <Stack direction="row" spacing={1.25} useFlexGap flexWrap="wrap" sx={{ mb: 2 }}>
+      <Stack className="ticket-stats" direction="row" spacing={1.25} useFlexGap flexWrap="wrap" sx={{ mb: 2 }}>
         {statItems.map(([label, value, tone]) => <StatCard key={label} label={label} value={value} tone={tone} />)}
       </Stack>
 
@@ -167,8 +167,8 @@ export default function TicketManage() {
       </Paper>
 
       {error && <Alert severity="error" role="alert" action={<Button color="inherit" size="small" onClick={loadList}>重试</Button>} sx={{ mb: 2 }}>{error}</Alert>}
-      <Grid container spacing={2} alignItems="stretch">
-        <Grid item xs={12} lg={5} sx={{ minWidth: 0 }}>
+      <Box className="ticket-work-area">
+        <Box className="ticket-list-pane">
           <Paper variant="outlined" sx={{ height: '100%', overflow: 'hidden' }}>
             <Box sx={{ p: 1.5, display: 'flex', justifyContent: 'space-between', alignItems: 'center' }}><Typography variant="subtitle1" fontWeight={700}>最近工单</Typography><Typography variant="caption" color="text.secondary">共 {total} 条</Typography></Box>
             <Divider />
@@ -179,9 +179,9 @@ export default function TicketManage() {
             )}
             <Stack direction="row" alignItems="center" justifyContent="center" spacing={1} sx={{ p: 1.25 }}><IconButton aria-label="上一页" size="small" disabled={page <= 1 || loading} onClick={() => setPage(page - 1)}><NavigateBeforeIcon /></IconButton><Typography variant="caption">第 {page} / {totalPages} 页</Typography><IconButton aria-label="下一页" size="small" disabled={page >= totalPages || loading} onClick={() => setPage(page + 1)}><NavigateNextIcon /></IconButton></Stack>
           </Paper>
-        </Grid>
+        </Box>
 
-        <Grid item xs={12} lg={7} sx={{ minWidth: 0 }}>
+        <Box className="ticket-detail-pane">
           <Paper variant="outlined" sx={{ p: { xs: 2, md: 2.5 }, minHeight: 420 }}>
             {!selectedId ? <Box sx={{ py: 10, textAlign: 'center' }}><Typography variant="h6" color="text.secondary">选择一个工单开始处理</Typography><Typography variant="body2" color="text.secondary" sx={{ mt: 1 }}>工单详情、回复和状态操作会显示在这里</Typography></Box> : detailLoading ? <Box role="status" aria-label="正在加载工单详情" sx={{ py: 10, textAlign: 'center' }}><CircularProgress /></Box> : selectedTicket ? (
               <Stack spacing={2}>
@@ -194,8 +194,8 @@ export default function TicketManage() {
               </Stack>
             ) : <Alert severity="error">工单详情不存在或加载失败。</Alert>}
           </Paper>
-        </Grid>
-      </Grid>
+        </Box>
+      </Box>
     </Box>
   );
 }

frontend/src/admin/theme.css

@@ -32,6 +32,77 @@ body {
 [data-theme="dark"] ::-webkit-scrollbar-thumb { background: #49454f; }
 [data-theme="dark"] ::-webkit-scrollbar-thumb:hover { background: #938f99; }
 
+/* 工单工作区：占满 AdminLayout 内容区，桌面保持列表/详情主次比例。 */
+.ticket-workspace {
+  width: 100%;
+  max-width: none;
+  min-width: 0;
+  min-height: calc(100vh - 112px);
+}
+
+.ticket-workspace .ticket-stats {
+  width: 100%;
+}
+
+.ticket-work-area {
+  display: grid;
+  grid-template-columns: minmax(280px, 0.55fr) minmax(0, 1fr);
+  gap: 16px;
+  width: 100%;
+  min-width: 0;
+  min-height: calc(100vh - 280px);
+  align-items: stretch;
+}
+
+.ticket-list-pane,
+.ticket-detail-pane {
+  min-width: 0;
+  width: 100%;
+}
+
+.ticket-list-pane > .MuiPaper-root,
+.ticket-detail-pane > .MuiPaper-root {
+  width: 100%;
+  min-width: 0;
+  box-sizing: border-box;
+}
+
+.ticket-list-pane > .MuiPaper-root {
+  min-height: calc(100vh - 280px);
+}
+
+.ticket-detail-pane > .MuiPaper-root {
+  min-height: calc(100vh - 280px);
+}
+
+@media (max-width: 1199px) and (min-width: 700px) {
+  .ticket-work-area {
+    grid-template-columns: minmax(250px, 0.62fr) minmax(0, 1fr);
+    gap: 14px;
+  }
+}
+
+@media (max-width: 699px) {
+  .ticket-workspace {
+    min-height: 0;
+  }
+
+  .ticket-work-area {
+    grid-template-columns: minmax(0, 1fr);
+    min-height: 0;
+    gap: 16px;
+  }
+
+  .ticket-list-pane > .MuiPaper-root,
+  .ticket-detail-pane > .MuiPaper-root {
+    min-height: 0;
+  }
+
+  .ticket-detail-pane > .MuiPaper-root {
+    min-height: 480px;
+  }
+}
+
 /* 减弱动效偏好 */
 @media (prefers-reduced-motion: reduce) {
   *, *::before, *::after {