@font-face {
  font-family: 'Seshat';
  src: url(../fonts/Seshat.otf);
}

:root {
  --header_height: 30px;
  --nav-font-size: 23px;
  --hamburgerBarHeight: 3px;
}

header {
  height: var(--header_height);
  background-color: white;
  color: darkgray;
  font-family: Seshat;
  display : flex;
  align-items : center;
  position: relative;
  margin: 18px 0;
}

header .face {
  height: 100%;
}

header>a {
  height:100%;
}

#hamburger_btn {
  display: none;
}

#global_nav ul {
  display: flex;
  flex-wrap: wrap;
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
  margin-left: calc(var(--nav-font-size) * 1);
}

#global_nav ul li {
  list-style: none;
  display: flex;
  height: 100%;
  align-items: center;
  margin: 0 calc(var(--nav-font-size) * 1);
  letter-spacing: 10px;
}

#global_nav ul li a {
  text-decoration: none;
  color: #a9a9a9;
  letter-spacing: 0;
  font-size: var(--nav-font-size);
  line-height: calc(var(--nav-font-size) * 1.2);
}

#global_nav ul li a:hover {
  color: black;
}

/* リンクにマウスホバーしたら上下に線を出す */
#global_nav ul li a {
  position: relative;
  transition: .3s;
}

#global_nav ul li a::before,
#global_nav ul li a::after {
  position: absolute;
  content: '';
  width: 0;
  height: 1px;
  transition: .3s;
  background-color: black;
}

#global_nav ul li a::before {
  top: 0;
  left: 0;
}

#global_nav ul li a::after {
  bottom: 0;
  right: 0;
}

#global_nav ul li a:hover::before,
#global_nav ul li a:hover::after {
  width: 100%;
}

#lang_change_btns {
  position: absolute;
  right: 0;
  /* 言語選択が可能なページでのみvisibleにする */
  visibility: hidden;
  cursor: pointer;
}

#lang_change_btns .slash {
  margin: 0 5px;
}

#lang_change_btns .active {
  color: black;
}

/*スマホ向け*/
@media screen and (max-width: 750px) {
  header {
    justify-content: space-between;
  }

  #hamburger {
    width: calc(var(--nav-font-size) * 1.5);
    height: calc(var(--header_height));
    margin-bottom: var(--hamburgerBarHeight);
  }

  #hamburger_btn{
    display: block;
    position: relative;
    width: 100%;
    height: calc(100% - var(--hamburgerBarHeight) * 2);
    z-index: 3;
    box-sizing: border-box;
    cursor: pointer;
    -webkit-transition: all 400ms;
    transition: all 400ms;
  }

  #hamburger_btn span{
    position: absolute;
    width: 100%;
    height: var(--hamburgerBarHeight);
    background: black;
    -webkit-transition: all 400ms;
    transition: all 400ms;
  }

  #hamburger_btn span:nth-child(1) {
    top:0;
  }
  #hamburger_btn span:nth-child(2) {
    top: 50%;
  }
  #hamburger_btn span:nth-child(3) {
    top: 100%;
  }

  #hamburger_btn.open span {
    height: 1px;
  }

  #hamburger_btn.open span:nth-child(1){
    background: #fff;
    top: 12px;
    -webkit-transform: rotate(-45deg);
    -moz-transform   : rotate(-45deg);
    transform        : rotate(-45deg);
  }

  #hamburger_btn.open span:nth-child(2),#hamburger_btn.open span:nth-child(3){
    top: 12px;
    background :#fff;
    -webkit-transform: rotate(45deg);
    -moz-transform   : rotate(45deg);
    transform        : rotate(45deg);
  }

  #global_nav{
    position: fixed;
    top: 0;
    right: -100%;
    width: 100%;
    height: 100%;
    font-size: 16px;
    box-sizing: border-box;
    z-index: 2;
    padding-top: 50px;
    transition: .3s;
  }

  #global_nav.open{
    right: 0px;
    background: rgba(0, 0, 0, 0.9);
  }

  #global_nav ul{
    position: absolute;
    top: 25vh;
    align-items: flex-end;
    flex-direction: column;
    flex-wrap: nowrap;
    right: 2vw;
  }

  #global_nav ul li{
    margin-bottom: var(--nav-font-size);
    height: auto;
  }

  #global_nav ul li a{
    font-size:   var(--nav-font-size);
    line-height: var(--nav-font-size);
    color: white;
  }


  #global_nav ul li a:hover {
    color: white;
  }

  #global_nav ul li a::before,
  #global_nav ul li a::after {
    background-color: white;
  }

  #lang_change_btns {
    right: 50px;
  }
}