响应式布局—设备像素密度(-webkit-min-device-pixel-ratio)

常见值对照表：

-webkit-min-device-pixel-ratio: 1.0

All non-Retina Macs

Apple iPhone (1st generation)

Apple iPhone 3G

Apple iPhone 3GS

Apple iPad (1st generation)

Apple iPad 2

Apple iPad mini (1st generation)

Acer Iconia A500

Samsung Galaxy Tab 10.1

Samsung Galaxy S

-webkit-min-device-pixel-ratio: 1.3

Asus MemoPad HD 7

Google Nexus 7 (2012 model)

-webkit-min-device-pixel-ratio: 1.4

Nokia Lumia 520

-webkit-min-device-pixel-ratio: 1.5

Google Nexus S

HTC Desire

HTC Desire HD

HTC Incredible S

HTC Velocity

HTC Sensation

Kindle Fire HD

Samsung Galaxy S II

Sony Xperia Tablet Z

Sony Xperia U

-webkit-min-device-pixel-ratio: 2.0

All Macs with Retina displays

Apple iPhone 4

Apple iPhone 4S

Apple iPhone 5

Apple iPhone 5c

Apple iPhone 5s

Apple iPhone 6

Apple iPhone 6s

Apple iPhone 7

Apple iPad (3rd generation)

Apple iPad 4

Apple iPad Air

Apple iPad mini (2rd generation)

HTC One X

Google Galaxy Nexus

Google Nexus 4

Google Nexus 7 (2013 model)

Google Nexus 10

Motorola Moto X

Samsung Galaxy S III

Samsung Galaxy Note II

Sony Xperia S

Sony Xperia T

-webkit-min-device-pixel-ratio: 2.6

Nokia Lumia 930

Google Nexus 5X

-webkit-min-device-pixel-ratio: 3.0

HTC One (M7)

HTC Butterfly

Huawei Honor 6

Huawei Mate 9

Apple iPhone 6 Plus

Apple iPhone 6s Plus

Apple iPhone 7 Plus

LG G2

Nexus 5

Nexus 6

Motorola Moto G4

OnePlus One

Oppo Find 7 (X9076)

Samsung Galaxy S4

Samsung Galaxy Note 3

Samsung Galaxy Note 4

Sony Xperia Z

Xiaomi Mi 3