Upload user avatar with a custom upload button

index.html

<main>
 <input type="file" name="image" id="image" accept="image/*" />
    <div id="preview">
      <div id="avatar"></div>
      <button
        id="upload-button"
        aria-labelledby="image"
        aria-describedby="image"
      >
        🙂
      </button>
    </div>
</main>

script.js

const UPLOAD_BUTTON = document.getElementById("upload-button");
const FILE_INPUT = document.querySelector("input[type=file]");
const AVATAR = document.getElementById("avatar");

UPLOAD_BUTTON.addEventListener("click", () => FILE_INPUT.click());

FILE_INPUT.addEventListener("change", event => {
  const file = event.target.files[0];

  const reader = new FileReader();
  reader.readAsDataURL(file);

  reader.onloadend = () => {
    AVATAR.setAttribute("aria-label", file.name);
    AVATAR.style.background = `url(${reader.result}) center center/cover`;
  };
});

style.css

body {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

#avatar {
  background-color: antiquewhite;
  height: 200px;
  width: 200px;
  border: 3px solid #0af;
  border-radius: 50%;
  transition: background ease-out 200ms;
}

#preview {
  position: relative;
}

input[type="file"] {
  display: none;
}

button {
  padding: 18px;
  border-radius: 50%;
  border: none;
  cursor: pointer;
  background-color: #08f;
  box-shadow: 0px 3px 5px -1px rgba(0, 0, 0, 0.2),
    0px 6px 10px 0px rgba(0, 0, 0, 0.14), 0px 1px 18px 0px rgba(0, 0, 0, 0.12);
  transition: background-color ease-out 120ms;
  position: absolute;
  right: -5%;
  bottom: 0%;
}

button:hover {
  background-color: #45a;
}