/*
  cpt-city: jmn/jmn-c64 (cpt)

  A colourmap with monotonic luminance for simultaneous colour and
  grey-scale publications.

  J. McNames, "An effective color scale for simultaneous color and
  gray-scale publications," in IEEE Signal Processing Magazine,
  vol. 23, no. 1, pp. 82-96, Jan. 2006,

  author: James McNames
  copyright: Free to use
  year: 2009
  url: https://phillips.shef.ac.uk/pub/cpt-city/jmn
*/
linear-gradient(
  0deg,
  rgb(255, 255, 255)   0.000%,
  rgb(252, 246, 253)   1.587%,
  rgb(249, 238, 252)   3.175%,
  rgb(245, 231, 251)   4.762%,
  rgb(240, 223, 251)   6.349%,
  rgb(235, 217, 251)   7.936%,
  rgb(228, 210, 252)   9.524%,
  rgb(221, 205, 253)  11.111%,
  rgb(213, 200, 253)  12.698%,
  rgb(205, 195, 254)  14.286%,
  rgb(196, 192, 254)  15.873%,
  rgb(186, 190, 254)  17.460%,
  rgb(176, 188, 254)  19.048%,
  rgb(165, 188, 253)  20.635%,
  rgb(155, 188, 251)  22.222%,
  rgb(144, 189, 248)  23.809%,
  rgb(133, 191, 245)  25.397%,
  rgb(123, 194, 240)  26.984%,
  rgb(112, 198, 235)  28.571%,
  rgb(103, 202, 228)  30.159%,
  rgb( 93, 207, 221)  31.746%,
  rgb( 85, 212, 212)  33.333%,
  rgb( 77, 217, 202)  34.921%,
  rgb( 71, 223, 191)  36.508%,
  rgb( 65, 228, 179)  38.095%,
  rgb( 61, 233, 166)  39.682%,
  rgb( 58, 238, 152)  41.270%,
  rgb( 56, 243, 137)  42.857%,
  rgb( 55, 246, 122)  44.444%,
  rgb( 56, 249, 106)  46.032%,
  rgb( 59, 250,  90)  47.619%,
  rgb( 63, 250,  74)  49.206%,
  rgb( 70, 246,  59)  50.794%,
  rgb( 78, 238,  47)  52.381%,
  rgb( 86, 229,  36)  53.968%,
  rgb( 93, 218,  27)  55.556%,
  rgb(101, 206,  19)  57.143%,
  rgb(107, 194,  13)  58.730%,
  rgb(113, 181,   8)  60.318%,
  rgb(118, 167,   4)  61.905%,
  rgb(122, 154,   2)  63.492%,
  rgb(125, 140,   0)  65.079%,
  rgb(127, 127,   0)  66.667%,
  rgb(127, 114,   0)  68.254%,
  rgb(127, 101,   1)  69.841%,
  rgb(126,  88,   3)  71.429%,
  rgb(123,  77,   5)  73.016%,
  rgb(119,  66,   8)  74.603%,
  rgb(115,  56,  10)  76.191%,
  rgb(109,  46,  13)  77.778%,
  rgb(103,  38,  16)  79.365%,
  rgb( 96,  30,  18)  80.952%,
  rgb( 88,  24,  20)  82.540%,
  rgb( 80,  18,  22)  84.127%,
  rgb( 72,  13,  23)  85.714%,
  rgb( 63,   9,  23)  87.302%,
  rgb( 54,   6,  23)  88.889%,
  rgb( 46,   4,  22)  90.476%,
  rgb( 37,   2,  20)  92.064%,
  rgb( 29,   1,  18)  93.651%,
  rgb( 21,   0,  14)  95.238%,
  rgb( 13,   0,  10)  96.825%,
  rgb(  6,   0,   5)  98.413%,
  rgb(  0,   0,   0) 100.000%
);