static/style.css

body { font-family: Arial, sans-serif; margin: 20px; }
nav a { margin-right: 10px; }
.flashes li { list-style:none; padding:6px; margin:4px 0; border-radius:4px; }
.flashes .success { background:#d4edda; }
.flashes .danger { background:#f8d7da; }