* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Pretendard', sans-serif;
}

body {
    line-height: 1.6;
    color: #333;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: auto;
}

.header {
    background: #111;
    color: #fff;
    padding: 15px 0;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav a {
    color: #fff;
    margin-left: 20px;
    text-decoration: none;
}

.btn {
    display: inline-block;
    margin-top: 20px;
    padding: 12px 25px;
    background: #fff;
    color: #005bea;
    text-decoration: none;
    border-radius: 5px;
    font-weight: bold;
}

.btn.outline {
    background: transparent;
    border: 2px solid #fff;
    color: #fff;
}

.features {
    padding: 60px 0;
    text-align: center;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 30px;
}

.feature-item {
    background: #f4f4f4;
    padding: 30px;
    border-radius: 10px;
}

.review {
    padding: 60px 0;
    background: #fafafa;
    text-align: center;
}

.contact {
    padding: 60px 0;
    text-align: center;
    background: #005bea;
    color: white;
}

.card-image{
    overflow:hidden;
    border-radius:14px;
    box-shadow:0 8px 25px rgba(0,0,0,0.08);
    background:#fff;
    padding-bottom:20px;
    transition:all 0.3s ease;
}

.card-image:hover{
    transform:translateY(-6px);
    box-shadow:0 15px 35px rgba(0,0,0,0.12);
}

.card-image img{
        width:100%;
        height:auto;
        
        aspect-ratio: 4/3;
        
        object-fit:cover;
        
        border-radius:14px 14px 0 0;
}

.card-image h3{
    padding:15px 15px 5px 15px;
    font-size:18px;
    text-align:center;
}

.card-image p{
    padding:0 15px;
    text-align:center;
    font-size:14px;
    color:#666;
}

.footer {
    background: #111;
    color: #fff;
    text-align: center;
    padding: 20px 0;
}

/* ========================= */
/* 📱 반응형 (모바일 대응) */
/* ========================= */

@media (max-width: 992px) {
    .feature-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {

    .header .container {
        flex-direction: column;
    }

    .nav {
        margin-top: 10px;
    }

    .feature-grid {
        grid-template-columns: 1fr;
    }

    .hero {
        padding: 50px 20px;
    }

}

/* ========================= */
/* 🎞 슬라이드 배너 */
/* ========================= */
.top-banner img {
    transition: 0.4s ease;
}

.top-banner img:hover {
    transform: scale(1.02);
}
.slider {
    position: relative;
    width: 100%;
    height: 700px;
    overflow: hidden;
}

.slide {
    position: absolute;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    opacity: 0;
    transition: opacity 0.8s ease-in-out;
    cursor: pointer;
}
.slide-link {
    display: block;
    text-decoration: none;
    color: inherit;
    z-index: 2;
}
.slide.active {
    opacity: 1;
}

.overlay {
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.4);
    color: white;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 20px;
    z-index: 1;
    pointer-events: none;
}

.overlay-link {
    display: block;
    width: 100%;
    height: 100%;
    color: inherit;
    text-decoration: none;
    pointer-events: none;
}

.overlay h2 {
    font-size: 42px;
}

.overlay p {
    margin-top: 15px;
    font-size: 20px;
}

.prev, .next {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(0,0,0,0.5);
    border: none;
    color: white;
    font-size: 30px;
    padding: 10px 20px;
    cursor: pointer;
}

.prev { left: 20px; }
.next { right: 20px; }

/* 모바일 대응 */
@media (max-width: 768px) {
    .slider {
        height: 400px;
    }

    .overlay h2 {
        font-size: 24px;
    }

    .overlay p {
        font-size: 16px;
    }
}

.youtube-section {
    padding: 60px 0;
    background: #f5f5f5;
}

.youtube-grid {
    width: 90%;
    margin: auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.youtube-item {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 비율 */
    height: 0;
}

.youtube-item iframe {
    position: absolute;
    width: 100%;
    height: 100%;
    left: 0;
    top: 0;
    border-radius: 10px;
}

/* 태블릿 */
@media (max-width: 1024px) {
    .youtube-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* 모바일 */
@media (max-width: 768px) {
    .youtube-grid {
        grid-template-columns: 1fr;
    }
}

/* ===== EDULEE 유튜브 SECTION ===== */
.edulee-youtube-wrap {
    padding: 100px 0;
    background: #f7faff;
    text-align: center;
  }
  
  .edulee-youtube-inner {
    width: 90%;
    margin: auto;
  }
  
  .edulee-youtube-title {
    font-size: 36px;
    font-weight: 700;
    color: #002d72;
    margin-bottom: 8px;
  }
  
  .edulee-youtube-sub {
    font-size: 18px;
    color: #415a88;
    margin-bottom: 40px;
  }
  
  .edulee-youtube-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
  }
  
  .edulee-youtube-card {
    position: relative;
    padding-bottom: 80.25%;
    height: 0;
    box-shadow: 0px 12px 30px rgba(0, 0, 50, 0.15);
    border-radius: 15px;
    overflow: hidden;
    transition: transform 0.3s ease;
  }
  
  .edulee-youtube-card:hover {
    transform: translateY(-8px) scale(1.02);
  }
  
  .edulee-youtube-card iframe {
    position: absolute;
    width: 100%;
    height: 100%;
    border: 0;
    top: 0;
    left: 0;
    border-radius: 15px;
  }
  
  /* 반응형 */
  @media (max-width:1024px) {
    .edulee-youtube-grid {
      grid-template-columns: repeat(2,1fr);
    }
  }
    .edulee-youtube-title {
      font-size: 28px;
    }

    .image-grid {
        display:grid;
        grid-template-columns:repeat(auto-fit, minmax(250px,1fr));
        gap:20px;
        margin-top:40px;
    }
    
    .image-grid img {
        width:100%;
        height:260px;
        object-fit:cover;
        border-radius:10px;
        box-shadow:0 5px 20px rgba(0,0,0,0.1);
        transition:0.3s;
    }
    
    .image-grid img:hover {
        transform:scale(1.05);
    }
    img {
        width:100%;
        max-width:1200px;
              height:auto;
    margin:0 auto;
    display:block;

  }
  
  .card-image img{
    height:160px;
  }

  /* 캠퍼스 갤러리 */
.cella-campus-gallery {
    margin-top: 40px;
}

.cella-main-banner img {
    width: 100%;
    height: 420px;
    object-fit: cover;
    border-radius: 20px;
    margin-bottom: 25px;
    box-shadow: 0 15px 40px rgba(0,0,0,0.15);
}
.cella-hero {
    position: relative;
    background: url('./images/cella_campus.jpg') center/cover no-repeat;    
    height: 600px;
    border-radius: 0px; /* 완전 각지게 */
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 20px 50px rgba(0,0,0,0.15);
}

.cella-hero-box {
    position: relative;
    
    height: 600px;
    border-radius: 10px; /* 완전 각지게 */
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 20px 50px rgba(0,0,0,0.15);
    background: linear-gradient(
        120deg,
        rgba(0, 20, 60, 0.85),
        rgba(54, 104, 179, 0.75)
    );
    z-index: 1;
}

.cella-sub-images {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 25px;
}

.cella-sub-images img {
    width: 100%;
    height: 260px;
    object-fit: cover;
    border-radius: 18px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.12);
    transition: 0.3s ease;
}

.cella-sub-images img:hover {
    transform: scale(1.03);
}    

.cella-hero-content h1 {
    color: #ffffff;
    font-size: 48px;
    font-weight: 800;

    /* 부드러운 그림자 */
    text-shadow: 0 4px 12px rgba(0,0,0,0.6);
}

.cella-hero-content p {
    color: #E6F0FF;
    text-shadow: 0 2px 8px rgba(0,0,0,0.5);
}


.cella-gallery .image-wrap {
    display: flex;
    gap: 30px;
}

.cella-gallery img {
    width: 100%;
    border-radius: 25px;              /* 🔥 라운드 효과 */
    box-shadow: 0 15px 40px rgba(0,0,0,0.08);  /* 부드러운 그림자 */
    object-fit: cover;
    transition: 0.3s ease;
}

/* PC 화면 */
@media (min-width: 768px) {
    .cella-gallery .image-wrap img {
        flex: 1;     /* 두 개 동일 비율 */
        height: 420px;
    }
}

/* 모바일 화면 */
@media (max-width: 767px) {
    .cella-gallery .image-wrap {
        flex-direction: column;
    }

    .cella-gallery .image-wrap img {
        height: 250px;
    }
}