<button class="button">Submit</button>

.button {
  display: inline-block;
  padding: 10px 20px;
  background-color: #007BFF;
  color: white;
  border: none;
  border-radius: 4px;
  position: relative;
  font-size: 16px;
  cursor: pointer;
}

.button::before {
  content: '✓';
  margin-right: 10px;
  font-size: 16px;
}