It didnt use the space efficiently

chatgpt-streetcomplete-flyer.tex

@@ -1,7 +1,8 @@
-\documentclass[a5paper,twocolumn]{article}
-\usepackage[margin=1cm]{geometry}
+\documentclass[a5paper]{article}
+\usepackage[margin=0.5cm]{geometry}
 \usepackage{graphicx}
 \usepackage{color}
+\usepackage{multicol}
 
 \begin{document}
 
@@ -15,40 +16,30 @@
 
 \vspace{0.5cm}
 
+\begin{multicols}{2}
 {\large\textbf{What is StreetComplete?}}
 
-\vspace{0.5cm}
-
 StreetComplete is a mobile app that allows you to improve the map of your city by answering simple questions about the streets around you. With StreetComplete, you can add missing information like street names, missing sidewalks, and more.
 
-\vspace{1cm}
-
 {\large\textbf{How it works}}
 
-\vspace{0.5cm}
-
 - Download the StreetComplete app from the App Store or Google Play
 - Open the app and select the questions you want to answer
 - Go out and answer the questions by taking photos and adding information
 - Your contributions will be reviewed and added to the map
-\end{center}
 
-\begin{flushright}
 {\large\textbf{Why participate}}
 
-\vspace{0.5cm}
-
 - Help make your city more accessible
 - Improve the map for everyone
 - Learn more about the streets around you
-\vspace{1cm}
 
 {\large\textbf{Contact Information}}
 
-\vspace{0.5cm}
-
 Email: contact@streetcomplete.com
 
 Website: www.streetcomplete.com
-\end{flushright}
+\end{multicols}
+\end{center}
+
 \end{document}