<button class="nemengin nekavenes"><span>Отправить</span>
<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">
<path d="M24 0l-6 22-8.129-7.239 7.802-8.234-10.458 7.227-7.215-1.754 24-12zm-15 16.668v7.332l3.258-4.431-3.258-2.901z"/>
</svg></button>

.nekavenes {
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  -khtml-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

button {
  width: 198px;
  height: 52px;
  cursor: pointer;
  border: none;
  color: #fbf5f5;
  background-color: #7646a7;
  background-image: linear-gradient(
315deg
, #643694 0%, #8093e6 74%);
  border-radius: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: 500ms;
  box-shadow: 1px 1px 5px 0px rgb(78 73 73 / 69%), 0px 0px 3px 0px rgb(51 51 51 / 60%);
  border: 2px solid rgb(206 206 206 / 71%);
}

button svg {
  position: absolute;
  fill: white;
  width: 24px;
  height: 24px;
  transform: translateX(20px);
  transition: 1s;
}

button span {
  position: absolute;
  transform: translateX(-30px);
  transition: 1s;
}

button:focus {
  outline: none;
}

button:focus svg {
  transform: translateX(30px) translateY(-10px);
  width: 0px;
  height: 0px;
}

button:focus span {
  transform: translateX(0);
}