.top_img {
  background-image: url('/2021/assets/img/index/top.png');
  background-repeat: no-repeat;
  background-position: center;
  background-size: cover;
  margin: 0;
  padding: 68vh 0 10vh;
  height: calc(100vh - 57px);
}

.theme {
  display: flex;
  justify-content: center;
  align-items: center;
}

.theme_img {
  width: auto;
  height: 10vh;
  margin-right: 5vw;
}

.theme_desc {
  text-align: left;
}

.live_link {
  display: flex;
  width: 400px;
  height: 70px;
  line-height: 70px;
  font-size: 1.5rem;
  border: #ebebeb solid 1px;
  border-radius: 5px;
  margin: 5rem auto 1rem;
  transition: all .5s;
  text-decoration: none;
  position: relative;
}

.live_link:hover {
  border: #1f1f1f solid 1px;
}

.live_link span {
  color: #ebebeb;
  width: 100%;
  height: 100%;
  z-index: 1;
}

.live_link span::before {
  display: block;
  position: absolute;
  content: "";
  width: 0;
  top: 0;
  bottom: 0;
  background-color: #f5f5f5;
  z-index: -1;
  transition: .3s;
}

.live_link span:hover {
  color: #1f1f1f;
}

.live_link span:hover::before {
  width: 100%;
}

.embed_twitter {
  width: 90%;
  margin: auto;
}

@media screen and (orientation: portrait) {
  .top_img {
    background-image: url('/2021/assets/img/index/top_mobile.png');
  }
}

/* 900px以下 タブレット用 */
@media screen and (max-width: 900px) {}

/* 600px以下 スマホ用 */
@media screen and (max-width: 600px) {
  .live_link {
    width: 80%;
    height: 60px;
    line-height: 60px;
    font-size: 1rem;
    margin-top: 3rem;
  }

  .theme {
    flex-wrap: wrap;
  }

  .theme_img {
    margin-right: unset;
    margin-bottom: 2rem;
  }

  .theme_desc .b {
    text-align: center;
  }
}