body {
  background: #fff;
}

.contents_background {
  padding: 64px 160px;

  background: #def;
}

.contents_open {
  font-weight: bold;

  text-align: center;

  color: #cd5142;
}

.contents_open .contents_open_title .contents_open_title_sentence {
  position: relative;

  display: inline-block;
}

.contents_open .contents_open_title .contents_open_title_sentence br {
  display: none;
}

.contents_open .contents_open_title .contents_open_title_sentence span {
  font-size: 26px;
}

.contents_open .contents_open_title .contents_open_title_sentence span:before {
  position: absolute;
  top: 50%;
  right: 102%;

  width: 24px;

  content: '';

  border: #cd5142 2px solid;
}

.contents_open .contents_open_title .contents_open_title_sentence span:after {
  position: absolute;
  top: 50%;
  left: 102%;

  width: 24px;

  content: '';

  border: #cd5142 2px solid;
}

.contents_open img {
  width: 148px;
  height: 170px;
}

.contents_open_box {
  display: flex;
  justify-content: center;
}

.contents_open_btn {
  font-size: 30px;
  font-weight: bold;

  position: relative;

  display: flex;
  justify-content: center;

  width: 100%;
  margin: 32px 0;
  padding: 40px 80px;

  cursor: pointer;

  color: #fff;
  border-radius: 10px;
  background: #cd5142;
}

.contents_open_btn:hover {
  opacity: .7;
}

.contents_open_btn_start br {
  display: none;
}

.contents_open_btn_start span {
  position: relative;

  display: flex;
  align-items: center;

  white-space: nowrap;
}

.contents_open_btn_start span:before {
  position: absolute;
  top: -175%;
  left: 0;

  width: 148px;
  height: 170px;
  margin-left: -164px;

  content: '';

  background: url('../../images/g21premium/icon.png');
}

.contents_open_btn_start span:after {
  position: absolute;
  right: 0;

  width: 40px;
  height: 40px;
  margin-right: -56px;

  content: '';

  background: url('../../images/g21premium/start_btn.svg');
}


/*スマホ・タブレット用画面*/
@media screen and (max-width: 900px) {
  .contents_background {
    padding: 64px 24px;
  }

  .contents_open_btn {
    padding: 32px 100px 32px 100px;
  }

  .contents_open .contents_open_title {
    margin: 0 24px;
  }

  .contents_open .contents_open_title .contents_open_title_sentence span {
    font-size: 20px;
  }

  .contents_open .contents_open_title .contents_open_title_sentence span:before {
    border: #cd5142 1px solid;
  }

  .contents_open .contents_open_title .contents_open_title_sentence span:after {
    border: #cd5142 1px solid;
  }

  .contents_open_btn_start span {
    font-size: 20px;
  }

  .contents_open_btn_start span:before {
    top: auto;

    width: 100px;
    height: 115px;
    margin-left: -115px;

    background-repeat: no-repeat;
    background-size: contain;
  }

  .contents_open_btn_start span:after {
    width: 30px;
    height: 30px;
    margin-left: -46px;

    background-repeat: no-repeat;
    background-size: contain;
  }
}

@media screen and (max-width: 425px) {
  .contents_open .contents_open_title .contents_open_title_sentence span {
    font-size: 18px;
  }

  .contents_open_btn_start span {
    font-size: 16px;
  }

  .contents_open_btn_start br {
    display: inline-block;
  }
}


@media screen and (max-width: 375px) {
  .contents_open .contents_open_title .contents_open_title_sentence br {
    display: inline-block;
  }

  .contents_open_btn_start span {
    font-size: 14px;
  }
}


@media screen and (max-width: 320px) {
  .contents_open_btn {
    padding: 16px 70px 16px 70px;
  }

  .contents_open_btn_start span:before {
    width: 70px;
    height: 80px;
    margin-left: -80px;

    background-repeat: no-repeat;
    background-size: contain;
  }

  .contents_open_btn_start span:after {
    width: 26px;
    height: 26px;
    margin-left: -42px;

    background-repeat: no-repeat;
    background-size: contain;
  }
}