• Normal viewport mode
• viewport: force width 320px
• viewport: force width 1020px
• viewport: force width=device_width
• viewport: force initial-scale=2
• viewport: force width=device_width , and target-densitydpi=device-dpi
• viewport: force width=device_width , and target-densitydpi=high-dpi
• viewport: force width=device_width , and target-densitydpi=low-dpi