.sub_cont {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
  }
  
  .title_area {
    text-align: center;
    margin-bottom: 3rem;
    color: #fff;
  }
  
  .title_area .title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.4;
  }
  
  .title_area .sub_text {
    font-size: 1.4rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
    word-break: keep-all;
  }
  
  .title_area .text {
    font-size: 1.1rem;
    line-height: 1.8;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 1rem;
    word-break: keep-all;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
  }
  
  .title_area .text:last-child {
    margin-bottom: 0;
  }
  
  /* 강조 색상 */
  .green {
    color: #00FFAB;
    font-weight: 500;
  }
  
  .yellow {
    color: #FFD700;
    font-weight: 500;
  }
  
  /* 상단 섹션 스타일 */
  .sub_top {
    background: #111;
    color: white;
    padding: 3rem 0 2rem;
    text-align: center;
    position: relative;
    overflow: hidden;
  }
  
  .sub_top::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 50% 50%, rgba(0, 255, 171, 0.1) 0%, transparent 70%);
  }
  
  .sub_top_tit {
    padding: 40px 0 0;
    font-size: 3.5rem;
    font-weight: 700;
    letter-spacing: 0.2em;
    color: #fff;
    line-height: 1.2;
    text-align: center;
    position: relative;
    z-index: 1;
    animation: fadeInUp 1s forwards;
  }
  
  @keyframes fadeInUp {
    from {
      opacity: 0;
      transform: translateY(20px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }
  
  /* Content section */
  .about_wrap .cont {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
  }
  
  .box {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 40px;
    margin-top: 2rem;
    width: 100%;
  }
  
  .video_box {
    width: 100%;
    max-width: 800px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.1);
  }
  
  .video_box .inner {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
  }
  
  .video_box iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
  }
  
  .text_box {
    width: 100%;
    max-width: 800px;
    padding: 2rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: 50px;
  }
  
  .text_list {
    list-style: none;
    padding: 0;
  }
  
  .text_list li {
    margin-bottom: 25px;
    line-height: 1.8;
    color: rgba(255, 255, 255, 0.9);
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.6s ease;
    font-size: 1rem;
  }
  
  .text_list li:last-child {
    margin-bottom: 0;
  }
  
  .text_list li.show {
    opacity: 1;
    transform: translateY(0);
  }
  
  .text_list li span {
    font-weight: 600;
  }
  
  .text_list .green {
    color: #00FFAB;
  }
  
  .text_list .yellow {
    color: #FFD700;
  }
  
  /* 반응형 스타일 */
  @media (max-width: 1200px) {
    .sub_cont {
      width: 90%;
    }
  }
  
  @media (max-width: 992px) {
    .sub_top_tit {
      font-size: 3rem;
    }
  
    .title_area .title {
      font-size: 2.2rem;
    }
  
    .title_area .sub_text {
      font-size: 1.2rem;
    }
  
    .text_list li {
      font-size: 1rem;
    }
  }
  
  @media (max-width: 768px) {
    .sub_top {
      padding: 2.5rem 0 1.5rem;
    }
  
    .sub_top_tit {
      font-size: 2.8rem;
      padding: 30px 0 0;
      letter-spacing: 0.1em;
    }
  
    .sub_cont {
      padding: 3rem 1.5rem;
    }
  
    .title_area {
      margin-bottom: 2rem;
    }
  
    .title_area .title {
      font-size: 2rem;
      margin-bottom: 1.2rem;
    }
  
    .title_area .sub_text {
      font-size: 1.1rem;
      margin-bottom: 1.2rem;
    }
  
    .title_area .text {
      font-size: 1rem;
      margin-bottom: 1rem;
      padding: 0 1rem;
    }
  
    .box {
      gap: 30px;
    }
  
    .text_list li {
      font-size: 0.95rem;
      margin-bottom: 20px;
    }
  
    .about_wrap .cont {
      padding: 0 1.5rem;
    }
  
    .text_box {
      padding: 1.5rem;
    }
  
    .video_box {
      margin: 0 -1rem;
      width: calc(100% + 2rem);
      border-radius: 0;
    }
  }
  
  @media (max-width: 480px) {
    .sub_top {
      padding: 2rem 0 1rem;
    }
  
    .sub_top_tit {
      font-size: 2.5rem;
      padding: 20px 0 0;
    }
  
    .sub_cont {
      padding: 2rem 1rem;
    }
  
    .title_area .title {
      font-size: 1.8rem;
      margin-bottom: 1rem;
    }
  
    .title_area .sub_text {
      font-size: 1rem;
      margin-bottom: 1rem;
    }
  
    .title_area .text {
      font-size: 0.9rem;
      margin-bottom: 0.8rem;
    }
  
    .box {
      gap: 20px;
    }
  
    .text_list li {
      font-size: 0.9rem;
      margin-bottom: 15px;
    }
  
    .about_wrap .cont {
      padding: 0 1rem;
    }
  
    .text_box {
      padding: 1.2rem;
    }
  
    .video_box {
      margin: 0 -1rem;
      width: calc(100% + 2rem);
    }
  }

.top_banner {
    position: relative;
    transform: translateX(-50%);  /* 중앙 정렬 보정 */
    left: 50%;  /* 중앙으로 위치 */
    height: 500px;
    max-width: 1920px;
    /* 현대적인 교육/협업 공간 이미지 */
    background: url('https://images.unsplash.com/photo-1497215728101-856f4ea42174?w=1920&q=80') no-repeat center;
    background-size: cover;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 160px;
}

.top_banner::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(0,0,0,0.8), rgba(0,0,0,0.4));
}

.top_banner .cont {
    position: relative;
    z-index: 1;
}

.top_banner .text {
    font-size: 3rem;
    line-height: 1.4;
    color: #fff;
    text-align: center;
    font-weight: 700;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
}

.top_banner .text span {
    color: #ffd700;
    font-weight: 800;
}

/* Responsive styles */
@media screen and (max-width: 1024px) {
    .box {
        flex-direction: column;
        gap: 40px;
        margin-top: -50px;
    }

    .video_box, .text_box {
        width: 100%;
    }
}

@media screen and (max-width: 768px) {
    .sub_top {
        height: 300px;
    }

    .sub_top_tit {
        font-size: 3rem;
    }

    .top_banner {
        height: 400px;
    }

    .top_banner .text {
        font-size: 2.2rem;
    }

    .m_br {
        display: block;
    }

    .text_list li {
        font-size: 0.9rem;
    }
}