我通过JS在HTML中设置cookie，之后进入Flask app并打印
JS Part：
<html>
<head>
<script>
document.cookie = "screen_color="+screen.colorDepth;
document.cookie = "screen_height="+screen.height;
document.cookie = "screen_width="+screen.width;
</script>
</head>
<body>
<p>Hello world</p>
</body>
</html>
烧瓶部分：
@app.route('/test', methods=['GET', 'POST'])
def test():
screen_color = request.cookies.get('screen_color')
screen_height = request.cookies.get('screen_height')
screen_width = request.cookies.get('screen_width')
print(screen_color, screen_width, screen_height)
return 'ok'
在Chrome中一切正常：我加载页面和python打印cookie值，但在Safari中，Python打印无。
我做错了什么？