パカッと周りに開くメニューボタン（周囲に分かれて開閉）

<div class="radial-wrapper">
  <button class="radial-button" id="menu-toggle">＋</button>
  <nav class="radial-menu" id="radial-menu">
    <a href="#">TOP</a>
    <a href="#">ABOUT</a>
    <a href="#">WORKS</a>
    <a href="#">CONTACT</a>
  </nav>
</div>

.radial-wrapper {
  position: relative;
  width: 100px;
  height: 100px;
  margin: 100px auto;
}

.radial-button {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: #d60000;
  color: #fff;
  font-size: 2rem;
  font-weight: bold;
  border: none;
  cursor: pointer;
  z-index: 10;
  position: absolute;
  top: 20px;
  left: 20px;
  transition: transform 0.3s ease;
}

.radial-button:hover {
  transform: rotate(90deg);
}

.radial-menu {
  position: absolute;
  top: 20px;
  left: 20px;
  width: 60px;
  height: 60px;
}

.radial-menu a {
  position: absolute;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: #111;
  color: #fff;
  text-align: center;
  line-height: 50px;
  text-decoration: none;
  font-size: 0.8rem;
  opacity: 0;
  transform: translate(0, 0);
  transition: all 0.4s ease;
  pointer-events: none;
}

/* 展開位置と表示 */
.radial-menu.open a:nth-child(1) {
  transform: translate(80px, 0);
  opacity: 1;
  pointer-events: auto;
}
.radial-menu.open a:nth-child(2) {
  transform: translate(60px, 60px);
  opacity: 1;
  pointer-events: auto;
}
.radial-menu.open a:nth-child(3) {
  transform: translate(0, 80px);
  opacity: 1;
  pointer-events: auto;
}
.radial-menu.open a:nth-child(4) {
  transform: translate(-60px, 60px);
  opacity: 1;
  pointer-events: auto;
}

const toggleBtn = document.getElementById("menu-toggle");
const radialMenu = document.getElementById("radial-menu");

toggleBtn.addEventListener("click", () => {
  radialMenu.classList.toggle("open");
});