<label for="avatar">Choose a profile picture:</label><br />

<input id="avatar" type="file" name="avatar" accept="image/png, image/jpeg" />

input {
  margin-top: 1rem;
}

input::file-selector-button {
  font-weight: bold;
  color: dodgerblue;
  padding: 0.5em;
  border: thin solid grey;
  border-radius: 3px;
}