[解決済み] Pure CSS 水平方向のテキストを切れ目なく連続的にスクロールさせる。

.marquee {
  margin: 0 auto;
  white-space: nowrap;
  overflow: hidden;
  position: absolute;
}

.marquee span {
  display: inline-block;
  padding-left: 100%;
  animation: marquee 5s linear infinite;
}

.marquee2 span {
  animation-delay: 2.5s;
}

@keyframes marquee {
  0% {
    transform: translate(0, 0);
  }
  100% {
    transform: translate(-100%, 0);
  }
}

<p class="marquee">
  <span>This is text - This is text - This is text - This is text - This is text - This is text - This is text - This is text - This is text - This is text - This is text - This is text -&nbsp;</span>
</p>
<p class="marquee marquee2">
  <span>This is text - This is text - This is text - This is text - This is text - This is text - This is text - This is text - This is text - This is text - This is text - This is text -&nbsp;</span>
</p>