diff --git a/blackboard/test.jpg b/blackboard/test.jpg
new file mode 100644
index 0000000..0a5f2ba
Binary files /dev/null and b/blackboard/test.jpg differ
diff --git a/css/body.css b/css/body.css
index 3d33fc2..eca9af3 100644
--- a/css/body.css
+++ b/css/body.css
@@ -1,6 +1,17 @@
 body {
     margin: 0;
     font-family: "Arial", sans-serif;
+
+    /* 背景图 */
+    background-image: url("../blackboard/test.jpg"); /* 图片地址 */
+    background-size: cover;                  /* 自动缩放并裁剪 */
+    background-position: center center;      /* 居中裁剪 */
+    background-repeat: no-repeat;            /* 不重复平铺 */
+
+    /* 铺满整个屏幕 */
+    width: 100vw;
+    height: 100vh;
+    overflow: hidden;
 }
 
 .main-layout {
diff --git a/css/chat.css b/css/chat.css
index 86a7ed6..c047e5c 100644
--- a/css/chat.css
+++ b/css/chat.css
@@ -3,9 +3,7 @@
     bottom: 50px;
     left: 0;
     width: 100%;
-    background: rgba(255, 255, 255, 0.05); /* 几乎全透明 */
-    backdrop-filter: blur(4px);            /* 模糊背景 */
-    -webkit-backdrop-filter: blur(4px);
+    background: rgba(255, 255, 255, 0); /* 几乎全透明 */
     display: flex;
     flex-direction: column;
     align-items: center;