header {
  position: sticky;
  top: 0;
  z-index: 999;
  /*margin: -8px;*/
  margin: 0;
}
body {
  font-weight: 400;
  font-family: "Suisse Int", "Noto Sans JP", sans-serif;
}
html, body {
  max-width: 100%;
  overflow-x: hidden;
  margin: 0;
  padding: 0;
}

.top {
  position: fixed;
}

.logo {
  height: 60px;
  width: 100%;
  position: fixed;
  display: inline-block;
  top: 0px;
  background-color: rgba(17, 18, 25, 0.77);
  margin: 0px;
  z-index: 1;
}


.logo p {
  display: inline-block;
  font-weight: 700;
  vertical-align: middle;
  margin: 10px 10px;
}

.logo a {
  display: inline-block;
  text-decoration: none;
  font-weight: 500;
  font-size: 25px;
  color: #ca4;
}

@media screen and (min-width: 600px){
  nav {
    display: block;
    position: fixed;
    background-color: rgba(0, 0, 0, 0.6); 
    width: 260px;
    top: 0;
    right: -300px;
    height: 470px;
    bottom: auto;
    transition: all 0.5s;
    z-index: 3;
    opacity: 0;
  }

  nav.active {
    right: 0;
    opacity: 1;
  
  }
  
  .open nav {
    right: 0;
    opacity: 1;
  }
  
  nav .inner {
    padding: 25px;
  }
  
  nav .inner ul {
    list-style: none;
    margin: 0;
    padding: 0;
  }
  
  nav .inner ul li {
    margin: 0;
    border-bottom: 1px solid #ffffff;
  }
  
  nav .inner ul li a {
    display: block;
    text-align: center;
    color: #ffffff;
    font-size: 14px;
    padding: 1rem;
    text-decoration: none;
    transition-duration: 0.2s;
  }
  
  nav .inner ul li a:hover {
    background: #e4e4e4;
    color: #ca4;
  }
  
  .toggle-btn {
    display: block;
    position: fixed;
    top: 30px;
    right: 30px;
    width: 30px;
    height: 30px;
    z-index: 3;
    cursor: pointer;
  }
  
  .toggle-btn span {
    position: absolute;
    display: block;
    right: 0;
    width: 30px;
    height: 2px;
    background-color: #ca4;
    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: #ca4;
  }
}

@media screen and (max-width: 600px){
  nav {
    display: block;
    position: fixed;
    background-color: rgba(0, 0, 0, 0.719); 
    width: 100%;
    top: 0;
    right: -300px;
    height: 100vh;
    bottom: auto;
    transition: all 0.5s;
    z-index: 3;
    opacity: 0;
    visibility: hidden;
  }

  nav.active {
    right: 0;
    opacity: 1;
  }
  
  .open nav {
    right: 0;
    opacity: 1;
    visibility: visible;
  }
  
  nav .inner {
    padding: 40px;
    height: 90vh;
  }
  
  nav .inner ul {
    list-style: none;
    height: 90vh;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
  }
  
  nav .inner ul li {
    flex-grow: 1; 
    display: flex;
    align-items: center;
    justify-content: center; 
    border-bottom: 1px solid #ffffff;
  }
  
  nav .inner ul li:last-child {
    border-bottom: none; 
  }
  
  nav .inner ul li a {
    width: 100%;
    text-align: center;
    color: #ffffff;
    font-size: 18px;
    padding: 2rem;
    text-decoration: none;
    transition-duration: 0.2s;
  }
  
  nav .inner ul li a:hover {
    background: #e4e4e4;
    color: #ca4;
  }
}
  



.toggle-btn {
  display: block;
  position: fixed;
  top: 15px;
  right: 30px;
  width: 30px;
  height: 30px;
  z-index: 3;
  cursor: pointer;
}

.toggle-btn span {
  position: absolute;
  display: block;
  right: 0;
  width: 30px;
  height: 2px;
  background-color: #ca4;
  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: #ca4;
}

.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;
  width: 100%;
  height: 100%;
  top: 0;
  right: 0;
  position: fixed;
  opacity: 0.8;
  z-index: 2;
  cursor: pointer;
}