<svg viewBox="0 0 600 300" class="svg-defs">
  <!-- Symbol wth text -->
  <symbol id="s-text">
    <text text-anchor="middle"
          x="50%"
          y="50%"
          dy=".35em"
          class="text"
          >
      Love
    </text>    
  </symbol>

  <!-- Mask with text -->
  <mask id="m-text"
        maskunits="userSpaceOnUse"
        maskcontentunits="userSpaceOnUse">
    <rect
          width="100%"
          height="100%"
          class="mask__shape">
    </rect>
    <use xlink:href="#s-text"
         class="text-mask"
         ></use>
  </mask>
</svg>

<div class="box-with-text">
  <!-- Content for text -->
  <div class="text-fill">
    <!-- Element with animated shadows -->
    <div class="shadows"></div>
  </div>

  <!-- SVG to cover text fill -->
  <svg viewBox="0 0 600 300"
       class="svg-inverted-mask">
    <!-- Big shape with hole in form of text -->
    <rect
          width="100%"
          height="100%"
          mask="url(#m-text)"
          class="shape--fill"/>
    <!-- Transparent copy of text to keep
         patterned text selectable -->
    <use xlink:href="#s-text"
         class="text--transparent"
         ></use>
  </svg> 
</div
@import url(http://fonts.googleapis.com/css?family=Open+Sans:800);

.svg-inverted-mask {
  position: absolute;
  width: 100%;
  height: 100%;
}

.mask__shape {
  fill: white;
}

.box-with-text {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
}

.text-fill {
  position: absolute;
  top: 50%;
  left: 50%;
  padding-top: 35vw;
  padding-left: 100%;
  margin: auto;
  overflow: hidden;
  -webkit-transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
}

.shape--fill {
  fill: lightgoldenrodyellow;
}

/* Transparent copy of text to keep patterned text selectable */
.text--transparent {
  fill: transparent;
}

/* Element with animated shadows */
.shadows {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 1vmax;
  height: 1vmax;
  background: gold;
  border-radius: 50%;
  box-shadow: 0 0 0 2vmax purple, 0 0 0 4vmax crimson, 0 0 0 6vmax red, 0 0 0 8vmax orangered, 0 0 0 10vmax tomato, 0 0 0 12vmax gold, 0 0 0 14vmax yellow, 0 0 0 16vmax yellowgreen, 0 0 0 18vmax turquoise, 0 0 0 20vmax royalblue, 0 0 0 22vmax mediumslateblue, 0 0 0 24vmax mediumorchid, 0 0 0 26vmax purple, 0 0 0 28vmax crimson, 0 0 0 30vmax red, 0 0 0 32vmax orangered, 0 0 0 34vmax tomato, 0 0 0 36vmax gold, 0 0 0 38vmax yellow, 0 0 0 40vmax yellowgreen, 0 0 0 42vmax turquoise, 0 0 0 44vmax royalblue, 0 0 0 46vmax mediumslateblue, 0 0 0 48vmax mediumorchid, 0 0 0 50vmax darkviolet, 0 0 0 52vmax purple, 0 0 0 54vmax crimson, 0 0 0 56vmax red, 0 0 0 58vmax orangered, 0 0 0 60vmax tomato, 0 0 0 62vmax gold, 0 0 0 64vmax yellow, 0 0 0 66vmax yellowgreen, 0 0 0 68vmax turquoise, 0 0 0 70vmax royalblue, 0 0 0 72vmax mediumslateblue, 0 0 0 74vmax mediumorchid, 0 0 0 76vmax darkviolet, 0 0 0 78vmax purple, 0 0 0 80vmax crimson, 0 0 0 82vmax red, 0 0 0 84vmax orangered, 0 0 0 86vmax tomato, 0 0 0 88vmax gold, 0 0 0 90vmax yellow;
  -webkit-animation: shadows-move 4s linear infinite;
  animation: shadows-move 4s linear infinite;
}

@media (min-aspect-ratio: 1 / 2) {
  .text-fill {
    padding-top: 35vw;
  }
}

@media (min-aspect-ratio: 2 / 1) {
  .text-fill {
    padding-top: 70vh;
    padding-left: 190vh;
  }
}

@-webkit-keyframes shadows-move {
  25% {
    box-shadow: 0 0 0 2vmax royalblue, 0 0 0 4vmax mediumslateblue, 0 0 0 6vmax mediumorchid, 0 0 0 8vmax purple, 0 0 0 10vmax crimson, 0 0 0 12vmax red, 0 0 0 14vmax orangered, 0 0 0 16vmax tomato, 0 0 0 18vmax gold, 0 0 0 20vmax yellow, 0 0 0 22vmax yellowgreen, 0 0 0 24vmax turquoise, 0 0 0 26vmax royalblue, 0 0 0 28vmax mediumslateblue, 0 0 0 30vmax mediumorchid, 0 0 0 32vmax darkviolet, 0 0 0 34vmax purple, 0 0 0 36vmax crimson, 0 0 0 38vmax red, 0 0 0 40vmax orangered, 0 0 0 42vmax tomato, 0 0 0 44vmax gold, 0 0 0 46vmax yellow, 0 0 0 48vmax yellowgreen, 0 0 0 50vmax turquoise, 0 0 0 52vmax royalblue, 0 0 0 54vmax mediumslateblue, 0 0 0 56vmax mediumorchid, 0 0 0 58vmax darkviolet, 0 0 0 60vmax purple, 0 0 0 62vmax crimson, 0 0 0 64vmax red, 0 0 0 66vmax orangered, 0 0 0 68vmax tomato, 0 0 0 70vmax gold, 0 0 0 72vmax yellow, 0 0 0 74vmax yellowgreen, 0 0 0 76vmax turquoise, 0 0 0 78vmax royalblue, 0 0 0 80vmax mediumslateblue, 0 0 0 82vmax mediumorchid, 0 0 0 84vmax darkviolet, 0 0 0 86vmax purple, 0 0 0 88vmax crimson, 0 0 0 90vmax red;
  }
  45% {
    box-shadow: 0 0 0 2vmax yellow, 0 0 0 4vmax yellowgreen, 0 0 0 6vmax turquoise, 0 0 0 8vmax royalblue, 0 0 0 10vmax mediumslateblue, 0 0 0 12vmax mediumorchid, 0 0 0 14vmax purple, 0 0 0 16vmax crimson, 0 0 0 18vmax red, 0 0 0 20vmax orangered, 0 0 0 22vmax tomato, 0 0 0 24vmax gold, 0 0 0 26vmax yellow, 0 0 0 28vmax yellowgreen, 0 0 0 30vmax turquoise, 0 0 0 32vmax royalblue, 0 0 0 34vmax mediumslateblue, 0 0 0 36vmax mediumorchid, 0 0 0 38vmax darkviolet, 0 0 0 40vmax purple, 0 0 0 42vmax crimson, 0 0 0 44vmax red, 0 0 0 46vmax orangered, 0 0 0 48vmax tomato, 0 0 0 50vmax gold, 0 0 0 52vmax yellow, 0 0 0 54vmax yellowgreen, 0 0 0 56vmax turquoise, 0 0 0 58vmax royalblue, 0 0 0 60vmax mediumslateblue, 0 0 0 62vmax mediumorchid, 0 0 0 64vmax darkviolet, 0 0 0 66vmax purple, 0 0 0 68vmax crimson, 0 0 0 70vmax red, 0 0 0 72vmax orangered, 0 0 0 74vmax tomato, 0 0 0 76vmax gold, 0 0 0 78vmax yellow, 0 0 0 80vmax yellowgreen, 0 0 0 82vmax turquoise, 0 0 0 84vmax royalblue, 0 0 0 86vmax mediumslateblue, 0 0 0 88vmax mediumorchid, 0 0 0 90vmax darkviolet;
  }
  75% {
    box-shadow: 0 0 0 2vmax orangered, 0 0 0 4vmax tomato, 0 0 0 6vmax gold, 0 0 0 8vmax yellow, 0 0 0 10vmax yellowgreen, 0 0 0 12vmax turquoise, 0 0 0 14vmax royalblue, 0 0 0 16vmax mediumslateblue, 0 0 0 18vmax mediumorchid, 0 0 0 20vmax purple, 0 0 0 22vmax crimson, 0 0 0 24vmax red, 0 0 0 26vmax orangered, 0 0 0 28vmax tomato, 0 0 0 30vmax gold, 0 0 0 32vmax yellow, 0 0 0 34vmax yellowgreen, 0 0 0 36vmax turquoise, 0 0 0 38vmax royalblue, 0 0 0 40vmax mediumslateblue, 0 0 0 42vmax mediumorchid, 0 0 0 44vmax darkviolet, 0 0 0 46vmax purple, 0 0 0 48vmax crimson, 0 0 0 50vmax red, 0 0 0 52vmax orangered, 0 0 0 54vmax tomato, 0 0 0 56vmax gold, 0 0 0 58vmax yellow, 0 0 0 60vmax yellowgreen, 0 0 0 62vmax turquoise, 0 0 0 64vmax royalblue, 0 0 0 66vmax mediumslateblue, 0 0 0 68vmax mediumorchid, 0 0 0 70vmax darkviolet, 0 0 0 72vmax purple, 0 0 0 74vmax crimson, 0 0 0 76vmax red, 0 0 0 78vmax orangered, 0 0 0 80vmax tomato, 0 0 0 82vmax gold, 0 0 0 84vmax yellow, 0 0 0 86vmax yellowgreen, 0 0 0 88vmax turquoise, 0 0 0 90vmax royalblue;
  }
}
@keyframes shadows-move {
  25% {
    box-shadow: 0 0 0 2vmax royalblue, 0 0 0 4vmax mediumslateblue, 0 0 0 6vmax mediumorchid, 0 0 0 8vmax purple, 0 0 0 10vmax crimson, 0 0 0 12vmax red, 0 0 0 14vmax orangered, 0 0 0 16vmax tomato, 0 0 0 18vmax gold, 0 0 0 20vmax yellow, 0 0 0 22vmax yellowgreen, 0 0 0 24vmax turquoise, 0 0 0 26vmax royalblue, 0 0 0 28vmax mediumslateblue, 0 0 0 30vmax mediumorchid, 0 0 0 32vmax darkviolet, 0 0 0 34vmax purple, 0 0 0 36vmax crimson, 0 0 0 38vmax red, 0 0 0 40vmax orangered, 0 0 0 42vmax tomato, 0 0 0 44vmax gold, 0 0 0 46vmax yellow, 0 0 0 48vmax yellowgreen, 0 0 0 50vmax turquoise, 0 0 0 52vmax royalblue, 0 0 0 54vmax mediumslateblue, 0 0 0 56vmax mediumorchid, 0 0 0 58vmax darkviolet, 0 0 0 60vmax purple, 0 0 0 62vmax crimson, 0 0 0 64vmax red, 0 0 0 66vmax orangered, 0 0 0 68vmax tomato, 0 0 0 70vmax gold, 0 0 0 72vmax yellow, 0 0 0 74vmax yellowgreen, 0 0 0 76vmax turquoise, 0 0 0 78vmax royalblue, 0 0 0 80vmax mediumslateblue, 0 0 0 82vmax mediumorchid, 0 0 0 84vmax darkviolet, 0 0 0 86vmax purple, 0 0 0 88vmax crimson, 0 0 0 90vmax red;
  }
  45% {
    box-shadow: 0 0 0 2vmax yellow, 0 0 0 4vmax yellowgreen, 0 0 0 6vmax turquoise, 0 0 0 8vmax royalblue, 0 0 0 10vmax mediumslateblue, 0 0 0 12vmax mediumorchid, 0 0 0 14vmax purple, 0 0 0 16vmax crimson, 0 0 0 18vmax red, 0 0 0 20vmax orangered, 0 0 0 22vmax tomato, 0 0 0 24vmax gold, 0 0 0 26vmax yellow, 0 0 0 28vmax yellowgreen, 0 0 0 30vmax turquoise, 0 0 0 32vmax royalblue, 0 0 0 34vmax mediumslateblue, 0 0 0 36vmax mediumorchid, 0 0 0 38vmax darkviolet, 0 0 0 40vmax purple, 0 0 0 42vmax crimson, 0 0 0 44vmax red, 0 0 0 46vmax orangered, 0 0 0 48vmax tomato, 0 0 0 50vmax gold, 0 0 0 52vmax yellow, 0 0 0 54vmax yellowgreen, 0 0 0 56vmax turquoise, 0 0 0 58vmax royalblue, 0 0 0 60vmax mediumslateblue, 0 0 0 62vmax mediumorchid, 0 0 0 64vmax darkviolet, 0 0 0 66vmax purple, 0 0 0 68vmax crimson, 0 0 0 70vmax red, 0 0 0 72vmax orangered, 0 0 0 74vmax tomato, 0 0 0 76vmax gold, 0 0 0 78vmax yellow, 0 0 0 80vmax yellowgreen, 0 0 0 82vmax turquoise, 0 0 0 84vmax royalblue, 0 0 0 86vmax mediumslateblue, 0 0 0 88vmax mediumorchid, 0 0 0 90vmax darkviolet;
  }
  75% {
    box-shadow: 0 0 0 2vmax orangered, 0 0 0 4vmax tomato, 0 0 0 6vmax gold, 0 0 0 8vmax yellow, 0 0 0 10vmax yellowgreen, 0 0 0 12vmax turquoise, 0 0 0 14vmax royalblue, 0 0 0 16vmax mediumslateblue, 0 0 0 18vmax mediumorchid, 0 0 0 20vmax purple, 0 0 0 22vmax crimson, 0 0 0 24vmax red, 0 0 0 26vmax orangered, 0 0 0 28vmax tomato, 0 0 0 30vmax gold, 0 0 0 32vmax yellow, 0 0 0 34vmax yellowgreen, 0 0 0 36vmax turquoise, 0 0 0 38vmax royalblue, 0 0 0 40vmax mediumslateblue, 0 0 0 42vmax mediumorchid, 0 0 0 44vmax darkviolet, 0 0 0 46vmax purple, 0 0 0 48vmax crimson, 0 0 0 50vmax red, 0 0 0 52vmax orangered, 0 0 0 54vmax tomato, 0 0 0 56vmax gold, 0 0 0 58vmax yellow, 0 0 0 60vmax yellowgreen, 0 0 0 62vmax turquoise, 0 0 0 64vmax royalblue, 0 0 0 66vmax mediumslateblue, 0 0 0 68vmax mediumorchid, 0 0 0 70vmax darkviolet, 0 0 0 72vmax purple, 0 0 0 74vmax crimson, 0 0 0 76vmax red, 0 0 0 78vmax orangered, 0 0 0 80vmax tomato, 0 0 0 82vmax gold, 0 0 0 84vmax yellow, 0 0 0 86vmax yellowgreen, 0 0 0 88vmax turquoise, 0 0 0 90vmax royalblue;
  }
}

/* Other styles */
html, body {
  height: 100%;
}

body {
  background: #fafad2;
  font: 14.5em/1 Open Sans, Impact;
  text-transform: uppercase;
  margin: 0;
}

.svg-defs {
  width: 0;
  height: 0;
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.