Make CSS background animaton not fade but to snap between colours

Question

I am currently playing / learning CSS animations and transitions and I want to make a simple animation where the background colour and text of a DIV alternate between two colors. This is pretty simple but my colours fade or blend from one to another and I would rather they snap or jump or toggle from one to another so the impact of the change is stronger. Here is my simple code


    I am some text

Here is my CSS

.boss {
        font-family: Helvetica, sans-serif;
        position: absolute;
        width: 100vw;
        height: 100vh;
        top: 0px;
        left: 0;
        background-color: #e91e63;
        display: flex;
        justify-content: center;
        align-items: center;
        color: white;
        font-size: 2em;
        text-transform: uppercase;
        animation: bg 1s linear infinite;
    }

@keyframes bg {
    0%  {
        background-color: #e91e63;
        color: white;
    }

    100%  {
        background-color: white;
        color: #e91e63;
    }
}

A jsbin of the code above is here: https://jsbin.com/macimep/edit?html,css,output

Can anyone tell me how I can make the colour change so it toggles rather than fades. I'm sure this isn't a hard question but everything I have tried so far hasn't worked. Also I want to do this with CSS, toggling with JavaScript is simple but I am trying to get to grips with CSS. Many thanks in advance

user_12163743 · Answer

If you don't need production ready code and just play with existing solutions, you can use animation-timing-function: steps(2, end); (see https://developer.mozilla.org/en-US/docs/Web/CSS/animation-timing-function#Step_examples).

You also can do :

@keyframes bg {
    0%,49%  {
        background-color: #e91e63;
        color: white;
    }

    50%,100%  {
        background-color: white;
        color: #e91e63;
    }
}

user_10742758 · Answer

Try this:

.boss {
  font-family: Helvetica, sans-serif;
  position: absolute;
  width: 100vw;
  height: 100vh;
  top: 0px;
  left: 0;
  background-color: #e91e63;
  display: flex;
  justify-content: center;
  align-items: center;
  color: white;
  font-size: 2em;
  text-transform: uppercase;
  animation: bg 1s linear infinite;
}

@keyframes bg {
  0%,
  49.99% {
    background-color: #e91e63;
    color: white;
  }
  50%,
  100% {
    background-color: white;
    color: #e91e63;
  }
}


  I am some text

Make CSS background animaton not fade but to snap between colours

2 Answers