OS Details

MacBook Pro 2017 (15 Inch) has been launched in Mid 2017.
MacBook Pro 2017 (15 Inch) have macOS Sierra

Device Size

MacBook Pro 2017 screen size is 15.4 inch screen . Physical dimensions for MacBook Pro 2017 (15 Inch) device is 0.61 x 13.75 INCH or ( 1.55 x 34.93 MM).

Displaying of Units are in this order "Height x Width"

Screen Pixel Density and CSS Pixel Ratio

"Pixel" is smallest unit/element of any display.

The total number of pixels that fit into an inch is referred to as "Screen Density" or "Pixel Density" and it measured as "Pixels Per Inch".
Pixel Desnsity have limits to display Pixels Per Inch depends on different screen sizes. When number of pixels per inch increases than it's screen-size limit, the Display resolution will increase but actual device width/height in pixels remain same. Actual device pixels are known as Device Independent Pixels or CSS Pixel Ratio.

MacBook Pro 2017 (15 Inch) resolution is 2880 x 1800 ^PX with ~ 220 pixel desnsity.
MacBook Pro 2017 (15 Inch) viewport size is 1440 x 900 ^PX with ~ 112 actual pixel density, which means it have 2.0 xhdpi display pixel density.

Screen Resolution and Viewport

The sum of pixels which are displaying on a device is called as "Screen Resolution". and sum of actual pixels of any device is reffered to as "Viewport".

MacBook Pro 2017 (15 Inch) have 15.4" physical screen size with IPS technology and it's native resolution is 2880 x 1800 Pixels with approximately 220 PPI pixel density. MacBook Pro 2017 (15 Inch) has viewport size 1440 x 900 Pixels and its pixel ratio is about 2.0.

MacBook Pro 2017 (15 Inch) supports scaled lower resolutions listed below:
- 1920 x 1200
- 1680 x 1050
- 1280 x 800
- 1024 x 640

MacBook Pro 2017 (15 Inch) built-in-display to support highly NATIVE resolutions upto 5K with use of thunderbolt or HDMI display devices. Here some list below:
- Up to two displays with 5120 x 2880 resolution at 60Hz
- Up to four displays with 4096 x 2304 resolution at 60Hz
- Up to four displays with 3840 x 2160 resolution at 60Hz

For better understanding screen actual sizes, viewport sizes, display resolution and about their density click here.

CSS Media Queries

MacBook Pro 2017 (15 Inch) Media Queries (In terms of Mobile only)

@media only screen and (min-width: 1440px) and (max-width: 767px) { /* Your Styles... */ }

MacBook Pro 2017 (15 Inch) Min-Width Media Queries

@media only screen and (min-width: 1440px) { /* Your Styles... */ }

MacBook Pro 2017 (15 Inch) Min-Height Media Queries

@media only screen and (min-height: 900px) { /* Your Styles... */ }

MacBook Pro 2017 (15 Inch) Landscape Media Queries

@media only screen and (min-width: 900px) and (orientation: landscape) { /* Your Styles... */ }

MacBook Pro 2017 (15 Inch) Portrait Media Queries

@media only screen and (min-width: 1440px) and (orientation: portrait) { /* Your Styles... */ }

MacBook Pro 2017 (15 Inch) Device Width Media Queries

@media only screen and (min-device-width: 1440px) and (orientation: portrait) { /* Your Styles... */ }
@media only screen and (min-device-width: 900px) and (orientation: landscape) { /* Your Styles... */ }

MacBook Pro 2017 (15 Inch) Retina Media Queries

@media
  only screen and (-webkit-min-device-pixel-ratio: 2.0),
  only screen and (   min--moz-device-pixel-ratio: 2.0),
  only screen and (     -o-min-device-pixel-ratio: 2.0/1),
  only screen and (        min-device-pixel-ratio: 2.0),
  only screen and (                min-resolution: 220dpi),
  only screen and (                min-resolution: 2.0dppx) { 
    /* Retina styles here */
}
                                

Retina is actually based upon device pixel ratio. Devices mostly have 2x or 3x display so you can use general retina media queries to display high resolution content on all kind of devices. Retina 2x and Retina 3x media queries given below:

Retina 2x Media Query

@media
  only screen and (-webkit-min-device-pixel-ratio: 2),
  only screen and (   min--moz-device-pixel-ratio: 2),
  only screen and (     -o-min-device-pixel-ratio: 2/1),
  only screen and (        min-device-pixel-ratio: 2),
  only screen and (                min-resolution: 192dpi),
  only screen and (                min-resolution: 2dppx) { 
    /* Retina styles here */
}
                                

Retina 3x Media Query

@media
  only screen and (-webkit-min-device-pixel-ratio: 3),
  only screen and (   min--moz-device-pixel-ratio: 3),
  only screen and (     -o-min-device-pixel-ratio: 3/1),
  only screen and (        min-device-pixel-ratio: 3),
  only screen and (                min-resolution: 384dpi),
  only screen and (                min-resolution: 3dppx) { 
    /* Retina styles here */
}
                                

MacBook Pro 2017 (15 Inch) Specifications

• Launch Date Mid 2017
• macOS Sierra
• Physical Screen Size 15.4 INCH
• Resolution 2880 x 1800 PX
• Viewport Size 1440 x 900 PX
• Pixel Density 220 PPI
• Device-Independent Pixels 112 PPI
• Pixel Ratio 2.0 xhdpi
• Width 2880 PX
• Height 1800 PX
• Device Width 1440 PX
• Device Height 900 PX
• Dimensions 1.55 x 34.93 cm (0.61 x 13.75 in)
• Weight 1.83 kg - 4.02 Pounds