feat(app): scaffold Vue3 frontend (stage 1)

app-frontend/src/style.css

@@ -0,0 +1,61 @@
+:root {
+  --app-bg: #f6f7fb;
+  --app-text: #111827;
+  --app-muted: #6b7280;
+  --app-border: rgba(17, 24, 39, 0.08);
+  --app-radius: 12px;
+  --app-shadow: 0 8px 24px rgba(17, 24, 39, 0.06);
+
+  font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI',
+    'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', Arial, sans-serif;
+  font-synthesis: none;
+  text-rendering: optimizeLegibility;
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
+}
+
+html,
+body,
+#app {
+  height: 100%;
+}
+
+body {
+  margin: 0;
+  background: var(--app-bg);
+  color: var(--app-text);
+}
+
+a {
+  color: inherit;
+  text-decoration: none;
+}
+
+.app-muted {
+  color: var(--app-muted);
+}
+
+@media (max-width: 768px) {
+  .el-dialog {
+    max-width: 92vw;
+  }
+
+  .el-form-item {
+    flex-direction: column;
+    align-items: stretch;
+  }
+
+  .el-form-item__label {
+    width: auto !important;
+    justify-content: flex-start !important;
+    padding: 0 0 6px !important;
+    line-height: 1.4;
+    text-align: left !important;
+  }
+
+  .el-form-item__content {
+    margin-left: 0 !important;
+    width: 100%;
+  }
+}
+