#navigation ul {
    display: block;
    margin: 0 auto;
    text-align: left;
  }

  #navigation ul li a:hover,
  #navigation ul li a:active {
    color: aqua;
  }
/* =======================================
　MENUが☓に
======================================= */
  #menu-btn-check {
    display: none;
  }
  .menu-btn p {
    display: block;
    width: 75px;
    margin-left: 35px;
    color: #fff;
  }
  .menu-btn span,
  .menu-btn span:before,
  .menu-btn span:after {
    content: '';
    display: block;
    height: 3px;
    width: 30px;
    border-radius: 3px;
    background-color: #ffffff;
    position: absolute;
  }
      .menu-btn span:before {
        bottom: 0.5em;
      }
      .menu-btn span:after {
        top: 0.5em;
      }
    #menu-btn-check:checked ~ .menu-btn span {
      background-color: rgba(255, 255, 255, 0);/*メニューオープン時は真ん中の線を透明にする*/
    }
    #menu-btn-check:checked ~ .menu-btn span::before {
      bottom: 0;
      transform: rotate(45deg);
    }
    #menu-btn-check:checked ~ .menu-btn span::after {
      top: 0;
      transform: rotate(-45deg);
    }
    #menu-btn-check:checked ~ #navigation {
      left: 0;/*メニューを画面内へ*/
    }

    #navigation {
      width: calc(100% - 300px);
      height: 100%;
      position: fixed;
      top: 0;
      left: 100%;/*leftの値を変更してメニューを画面外へ*/
      z-index: 80;
      background-color: #5295b3;
      transition: all 0.5s;/*アニメーション設定*/
  }

  #navigation ul {
    padding: 70px 10px 0;
  }
  #navigation ul li {
    padding: 1em 0.5em;
    border-bottom: solid 1px #ffffff;
    list-style: none;
  }
  #navigation ul li a {
    display: block;
    width: 100%;
    font-size: 15px;
    box-sizing: border-box;
    text-decoration: none;
    padding: 9px 15px 10px 0;
    position: relative;
  }
  #menu-btn-check {
    display: none;
  }
  #navigation a,
  #navigation a:link,
  #navigation a:active,
  #navigation a:visited,
  #navigation a:hover {
    color: #ffffff;
    text-decoration: none;
  }
  #navigation ul li a::before {
    content: "";
    width: 7px;
    height: 7px;
    border-top: solid 2px #ffffff;
    border-right: solid 2px #ffffff;
    transform: rotate(45deg);
    position: absolute;
    right: 1em;
    top: 1em;
  }

/*///////////////////////////////////////
  Media Query
///////////////////////////////////////*/
@media screen and (min-width: 960px) {
  #navigation ul {
    width: 80%;
  }
    .menu-btn {
      position: fixed;
      top: 10px;
      right: 0;
      display: flex;
      justify-content: flex-start;
      align-items: center;
      width: 130px;
      height: 60px;
      z-index: 90;
      background-color: #5295b3;
      border-radius: 0.5em 0 0 0.5em;/* 左上 | 右上 | 右下 | 左下 */
    }

    #menu-btn-check:checked ~ .menu-btn {
      width: 200px;
      transition: all 0.5s;
    }
}
@media screen and (min-width: 521px) and (max-width: 959px) {
  #navigation ul {
    width: 90%;
  }
    .menu-btn {
      position: fixed;
      top: 100px;
      right: 0;
      display: flex;
      justify-content: flex-start;
      align-items: center;
      width: 120px;
      height: 75px;
      z-index: 90;
      background-color: #5295b3;
      border-radius: 0.5em 0 0 0.5em;/* 左上 | 右上 | 右下 | 左下 */
    }
}
  @media screen and (max-width: 520px) {
    #navigation ul {
      width: 90%;
    }
    .menu-btn {
      position: fixed;
      top: 15px;
      right: 0;
      display: flex;
      justify-content: flex-start;
      align-items: center;
      width: 80px;
      height: 60px;
      z-index: 90;
      background-color: #5295b3;
      border-radius: 0.5em 0 0 0.5em;/* 左上 | 右上 | 右下 | 左下 */
    }
    .menu-btn span {
      margin-left: 25px;
    }
    .menu-btn p {
      display: none;
    }
    #navigation ul li {
      padding: 0.5em 0.5em;
    }
  }

  @media screen and (min-width: 768px) {
    #menu-btn-check:checked ~ #navigation {
      left: 60%;
    }
    #navigation {
      width: 30%;
    }
}
@media screen and (max-width: 768px) {
    #menu-btn-check:checked ~ #navigation {
      left: 0;
    }
    #navigation {
      width: 75%;
      height: 85%;
      overflow: auto;
    }
    #navigation ul {
      padding: 1em 10px 0;
    }
}