Why doesn't css see the font-family?

Question

css

Hello everyone, I downloaded the fonts to my folder, I connect them (sass):

@font-face
  font-family: 'Lato'
  src: url('../fonts/Lato-Black.ttf') format('ttf')
  font-weight: 900

@font-face
  font-family: 'Lato'
  src: url('../fonts/Lato-Regular.ttf') format('ttf')
  font-weight: 400

@font-face
  font-family: 'PlayfairDisplay'
  src: url('../fonts/PlayfairDisplay-Regular.otf') format('otf')
  font-weight: normal

After connecting, fonts are not displayed if sans-serif is written in font-family along with the font name.
If you remove sans-serif, then the font is displayed adequately

Answer 1

try

body {
font-family: 'Lato', sans-serif;
}