html - How can I achieve a text loading animation over multiple lines?

Question

I'm trying to implement a text loading animation using only CSS. what I have is a text with black color, then when the page loads the text will fill start filling with a red color over several seconds.

The issue I'm facing is that the text loading animation is working fine, but when the text ends and begins with a new line the animation text still continues on the same line.

How can I fix this?

body {
  background: #3498db;
  font-family: sans-serif;
}

h1 {
  position: relative;
  color: rgba(0, 0, 0, .3);
  font-size: 5em;
  white-space: wrap;
}

h1:before {
  content: attr(data-text);
  position: absolute;
  overflow: hidden;
  max-width: 100%;
  white-space: nowrap;
  word-break: break-all;
  color: #fff;
  animation: loading 8s linear;
}

@keyframes loading {
  0% {
    max-width: 0;
  }
}

<h1 data-text="Suspendisse mollis dolor vitae porta egestas. Nunc nec congue odio.">Suspendisse mollis dolor vitae porta egestas. Nunc nec congue odio.</h1>

Answer 1

An idea is to consider gradient coloration with background-clip: text applied to an inline element.

body {
  background: #3498db;
  font-family: sans-serif;
}

h1 {
  font-size: 5em;
}

h1 span {
  background:
    linear-gradient(#fff,#fff) left no-repeat
    rgba(0, 0, 0, .3);
  background-size:0% 100%;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  animation:loading 5s forwards linear;
}

@keyframes loading {
  to {
    background-size:100% 100%;
  }
}

<h1><span>Suspendisse mollis dolor vitae porta egestas. Nunc nec congue odio.</span></h1>