body {
  font-weight: 400;
}

main {
  padding: 50px;
}

main h1 {
  font-weight: 400;
  text-align: center;
}

nav {
  display: block;
  position: fixed;
  background-color: #ffffff;
  width: 230px;
  top: 0;
  left: -300px;
  bottom: 0;
  transition: all 0.5s;
  z-index: 3;
  opacity: 0;
}

.open nav {
  left: 0;
  opacity: 1;
}

nav .inner {
  padding: 31px;
}

nav .inner ul {
  list-style: none;
  margin: 50;
  padding: 0;
}

nav .inner ul li {
  margin: 0;
  border-bottom: 1px solid #333;
}

nav .inner ul li a {
  display: block;
  color: #333;
  font-size: 15px;
  padding: 1.2rem;
  text-decoration: none;
  transition-duration: 0.2s;
}

nav .inner ul li:nth-child(1) a {
  background-color: #e4e4e4;  /* 3階のリンクの背景色を変更 */
}

nav .inner ul li a:hover {
  background: #e4e4e4;
}

.room-number {
    
  color: #111;
}

 

.toggle-btn {
  display: block;
  position: fixed;
  top: 20px;
  left: 30px;
  width: 40px;
  height: 30px;
  z-index: 3;
  cursor: pointer;
}

.toggle-btn span {
  position: absolute;
  display: block;
  left: 0;
  width: 40px;
  height: 3px;
  background-color: #fff;
  transition: all 0.5s;
  border-radius: 4px;
}

.toggle-btn span:nth-child(1) {
  top: 4px;
}
.toggle-btn span:nth-child(2) {
  top: 14px;
}
.toggle-btn span:nth-child(3) {
  bottom: 4px;
}

.open .toggle-btn span {
  background-color: #000000;
}

.open .toggle-btn span:nth-child(1) {
  transform: translateY(10px) rotate(-315deg);
}

.open .toggle-btn span:nth-child(2) {
  opacity: 0;
}

.open .toggle-btn span:nth-child(3) {
  transform: translateY(-10px) rotate(315deg);
}

#mask {
  display: none;
  transition: all 0.5s;
}

.open #mask {
  display: block;
  background: #000;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  position: fixed;
  opacity: 0.8;
  z-index: 2;
  cursor: pointer;
}