/* メニュー */

body {
  position: relative;
}

.menu-btn {
  position: fixed;
  top: 1rem;
  right: 1rem;
  border: none;
  font-size: 2rem;
  cursor: pointer;
  z-index: 999999;
}

.menu ul {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  height: 100%;
  list-style: none;
  padding: 0;
}

.menu ul li {
  margin-bottom: 1rem;
}

.menu ul li a {
  color: #544;
  font-size: 1.5rem;
  text-decoration: none;
}

.menu {
  background-color: rgba(255, 255, 255, 0.9);
  opacity: 0;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 0;
  z-index: 999998;
  box-sizing: border-box;
  overflow-y: auto;
  transition: height 0.3s, opacity, 0.3s;
}

.open {
  height: 100%;
  opacity: 1;
}