/* ヘッダー */
  .header {
    background-color: gray;
    width: 100%;
    height: 50px;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 999;
  }
  
  .header__inner {
    padding: 0 0 0 10px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: inherit;
    position: relative;
  }

  .header a{
    margin-top: 10px;
  }
  .header img{
    margin-right: 0;
  }
  .header h1{
    margin-top: 30px;
  }
  .header a:visited{
    color: #000;
  }
  .header a:link{
    color: #000;
  }
  
  
  @media screen and (min-width: 640px) {
    .header__title {
      width: 160px;
    }
  }
  
  .header__title img {
    display: block;
    width: 100%;
    height: 100%;
  }
  
  .header__nav {
    position: absolute;
    right: 0;
    left: 0;
    top: 0;
    width: 100%;
    height: 100vh;
    transform: translateX(100%);
    background-color: #bbb;
    transition: ease .4s;
  }
  
  
  @media screen and (min-width: 640px) {
    .header__inner {
      padding: 0 0 0 10px;
      display: flex;
      align-items: center;
      justify-content: flex-start;
      height: inherit;
      position: relative;
    }
    .header__nav {
      position: static;
      transform: initial;
      background-color: inherit;
      height: inherit;
      display: flex;
      justify-content: end;
      width: 60%;
      margin-left: 5vw;
    }
  }
  
  
  @media screen and (min-width: 640px) {
    .nav__items {
      width: 100%;
      display: flex;
      align-items: center;
      height: initial;
      justify-content: flex-start;
    }
  }
  
  .nav-items {
    position: absolute;
    top: 40%;
    left: 50%;
    transform: translate(-50%, -50%);
    padding: 0;
  }
  
  
  @media screen and (min-width: 640px) {
    .nav-items {
      padding-top: inherit;
      padding-bottom: inherit;
      position: inherit;
      top: 0;
      left: 0;
      transform: translate(0, 0);
    }
  }
  
  .nav-items__item a {
    color: black;
    width: 100%;
    display: block;
    text-align: center;
    font-size: 30px;
    margin-bottom: 24px;
  }
  
  .nav-items__item:last-child a {
    margin-bottom: 0;
  }
  
  @media screen and (min-width: 640px) {
    .nav-items__item a {
      font-size: 120%;
      width: 100%;
      margin-bottom: 0;
      margin-right: 40px;
    }
  }
  
  
  /* ハンバーガーメニュー */
  .header__hamburger {
    width: 48px;
    height: 100%;
  
  }
  
  .hamburger {
    background-color: transparent;
    border-color: transparent;
    z-index: 9999;
  }
  
  @media screen and (min-width: 640px) {
    .hamburger {
      display: none;
    }
  }
  
  
  .hamburger span {
    width: 100%;
    height: 3px;
    background-color: #fff;
    border-radius: 10px;
    position: relative;
    transition: ease .4s;
    display: block;
  }
  
  .hamburger span:nth-child(1) {
    top: 0;
  }
  
  .hamburger span:nth-child(2) {
    margin: 8px 0;
  }
  
  .hamburger span:nth-child(3) {
    top: 0;
  }
  
  
  /* ハンバーガーメニュークリック後のスタイル */
  .header__nav.active {
    transform: translateX(0);
  }
  
  .hamburger.active span:nth-child(1) {
    top: 5px;
    transform: rotate(45deg);
  }
  
  .hamburger.active span:nth-child(2) {
    opacity: 0;
  
  }
  
  .hamburger.active span:nth-child(3) {
    top: -13px;
    transform: rotate(-45deg);
  }