シャドウ付き立体風ボタン（押すとメニューがスライドダウン表示）

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

.menu-wrapper {
  position: relative;
  text-align: center;
  margin-top: 40px;
}

.press-button {
  background: linear-gradient(to bottom, #f44336, #c62828);
  color: #fff;
  padding: 14px 28px;
  font-size: 1rem;
  border: none;
  border-radius: 30px;
  box-shadow: 0 5px 0 #7f1d1d;
  cursor: pointer;
  transition: transform 0.1s, box-shadow 0.1s;
}
.press-button:active {
  transform: translateY(5px);
  box-shadow: 0 0 0 #7f1d1d;
}

.slide-menu {
  position: absolute;
  top: 60px;
  left: 50%;
  transform: translateX(-50%) translateY(-10px);
  opacity: 0;
  pointer-events: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: all 0.3s ease;
  z-index: 10;
}

.slide-menu.open {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
  pointer-events: auto;
}

.slide-menu a {
  background: #111;
  color: #fff;
  padding: 10px 16px;
  border-radius: 20px;
  text-decoration: none;
  font-size: 0.9rem;
}

.slide-menu a:hover {
  background: #f44336;
}

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

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