I don’t know how to force it at startup, but I found a neat way to properly scale your content when changing from “Portrait” to “Landscape”, especially if you use canvas.
<head> <meta name="viewport" content="initial-scale=1.6; maximum-scale=1.0; width=device-width; "/> ... </head>
So, as soon as your user switches the phone to landscape mode, your page will appear in the correct timeline.
user141682
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