diff --git a/web/static/css/c2.css b/web/static/css/c2.css
index 4ce3ab63..89af3bbc 100644
--- a/web/static/css/c2.css
+++ b/web/static/css/c2.css
@@ -2411,13 +2411,21 @@ html[data-theme="dark"] .c2-session-main-empty__icon {
     width: 100%;
     max-width: 540px;
     max-height: 85vh;
-    overflow-y: auto;
+    overflow: hidden;
     box-shadow: var(--c2-shadow-lg);
     border: 1px solid var(--c2-border);
     animation: c2-slide-up 0.18s ease-out;
     contain: layout style paint;
 }
 
+.c2-modal > #c2-modal-content {
+    display: flex;
+    flex-direction: column;
+    width: 100%;
+    max-height: inherit;
+    min-height: 0;
+}
+
 @keyframes c2-slide-up {
     from { opacity: 0; transform: translateY(12px) scale(0.98); }
     to { opacity: 1; transform: translateY(0) scale(1); }
@@ -2427,6 +2435,7 @@ html[data-theme="dark"] .c2-session-main-empty__icon {
     display: flex;
     justify-content: space-between;
     align-items: center;
+    flex: 0 0 auto;
     padding: 24px 28px 20px;
     border-bottom: 1px solid var(--c2-border);
 }
@@ -2439,15 +2448,22 @@ html[data-theme="dark"] .c2-session-main-empty__icon {
 
 /* .c2-modal-close 样式见 style.css 统一关闭按钮 */
 
-.c2-modal-body { padding: 24px 28px; }
+.c2-modal-body {
+    flex: 1 1 auto;
+    min-height: 0;
+    overflow-y: auto;
+    padding: 24px 28px;
+    scrollbar-gutter: stable;
+}
 
 .c2-modal-footer {
     display: flex;
     justify-content: flex-end;
     gap: 10px;
+    flex: 0 0 auto;
     padding: 16px 28px;
     border-top: 1px solid var(--c2-border);
-    background: var(--c2-surface-alt);
+    background: var(--c2-surface);
     border-radius: 0 0 16px 16px;
 }