.intro__txt {
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.intro__nav {
  display: flex;
  flex-wrap: wrap;
  border-top: 1px solid #e0e0e0;
  border-left: 1px solid #e0e0e0;
}
.intro__nav > a {
  width: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  padding: 15px 10px;
  border-right: 1px solid #e0e0e0;
  border-bottom: 1px solid #e0e0e0;
  font-size: 1.6rem;
  font-weight: 500;
  color: #404040;
}
.intro__nav > a > span {
  display: block;
}
.intro__nav > a > span > span + span {
  display: none;
}
.intro__nav > a::after {
  content: "";
  display: block;
  width: 8px;
  height: 8px;
  border-right: 2px solid #2798CB;
  border-bottom: 2px solid #2798CB;
  transform: rotate(45deg);
  flex-shrink: 0;
}

.message__name {
  text-align: right;
  font-size: 1.6rem;
  font-weight: 500;
}

.group__list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
}

.group__card-img {
  width: 100%;
  height: 130px;
  line-height: 1;
  place-content: center;
  text-align: center;
  border: 1px solid rgba(112, 112, 112, 0.3);
  margin-bottom: 10px;
}

.group__name {
  margin-bottom: 10px;
}
.group__name > a {
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 16px;
  color: #404040;
  font-size: 1.4rem;
}
.group__name > a > img {
  width: 14px;
  height: 14px;
}
@media screen and (min-width: 768px) {
  .intro__nav > a {
    width: 25%;
    padding: 20px;
    font-size: 1.8rem;
  }
  .intro__nav > a > span {
    position: relative;
    overflow: hidden;
  }
  .intro__nav > a > span > span {
    display: block;
    transition: transform 0.4s ease;
  }
  .intro__nav > a > span > span + span {
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    transform: translateY(100%);
  }
  .intro__nav > a:hover {
    opacity: 1;
  }
  .intro__nav > a:hover > span > span:first-child {
    transform: translateY(-100%);
  }
  .intro__nav > a:hover > span > span + span {
    transform: translateY(0);
  }
  .message__name {
    font-size: 1.8rem;
  }
  .group__list {
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
  }
  .group__card-img {
    height: 160px;
  }
  .group__name > a {
    font-size: 1.6rem;
  }
}