add background

app.py

@@ -201,6 +201,32 @@ def analyze_youtube_video(video_url_or_id: str):
 # Page configuration: Set to centered layout (default) instead of "wide"
 st.set_page_config(page_title="Social Sentiment Analysis", layout="centered")
 
+st.markdown(
+    """
+    <style>
+    .stApp {
+        background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
+        color: white;
+    }
+
+    /* Tùy chỉnh text và component */
+    .stTextInput > div > div > input,
+    .stTextArea textarea,
+    .stButton>button,
+    .stSelectbox>div>div {
+        background-color: #1e1e1e;
+        color: white;
+    }
+
+    .stButton>button:hover {
+        background-color: #333333;
+        color: white;
+    }
+    </style>
+    """,
+    unsafe_allow_html=True,
+)
+
 st.title("📊 SOCIAL SENTIMENT ANALYSIS")
 # A little description for the user
 st.write(