body {
  font-family: Verdana, sans-serif;
  margin: 0;
  background-color: #e1fbe9;
  color: #333;
}

* {
  box-sizing: border-box;
}

.header-container {
    width: 100%;
    padding: 20px;
    text-align: center;
    background-color: #e1fbe9;
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); 
    gap: 15px; 
    padding: 15px;
    max-width: 1600px;
    margin: 0 auto;
}

.gallery-item {
    position: relative;
    overflow: hidden;
    border-radius: 4px;
    background: #000;
    cursor: pointer;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.gallery-item:hover {
    transform: scale(1.03);
    box-shadow: 0 8px 15px rgba(0,0,0,0.2);
    z-index: 2;
}

.gallery-item img, 
.gallery-item video {
    width: 100%;
    height: 250px;
    object-fit: cover;
    display: block;
}

.gallery-item video {
    opacity: 0.9;
}

.play-icon {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 50px;
    color: white;
    opacity: 0.8;
    pointer-events: none;
    text-shadow: 0 0 10px rgba(0,0,0,0.5);
    z-index: 5;
}

.gallery-item:hover .play-icon {
    transform: translate(-50%, -50%) scale(1.2);
    opacity: 1;
}

.lightbox {
    display: none; 
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    background-color: rgba(0, 0, 0, 0.95);
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

.lightbox-content {
    position: relative;
    max-width: 90%;
    max-height: 85%;
    text-align: center;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

.lightbox-media {
    max-width: 100%;
    max-height: 80vh;
    box-shadow: 0 0 20px rgba(0,0,0,0.5);
    border: 1px solid #333;
}

#lightbox-youtube {
    width: 80vw;
    height: 45vw;
    max-width: 1280px;
    max-height: 720px;
}

.close {
    position: absolute;
    top: 20px;
    right: 35px;
    color: #f1f1f1;
    font-size: 40px;
    font-weight: bold;
    cursor: pointer;
    z-index: 1001;
}

.close:hover {
    color: #bbb;
}

.prev, .next {
    cursor: pointer;
    position: absolute;
    top: 50%;
    width: auto;
    padding: 16px;
    margin-top: -50px;
    color: white;
    font-weight: bold;
    font-size: 30px;
    transition: 0.3s;
    user-select: none;
    z-index: 1001;
    background-color: rgba(0,0,0,0.3);
    border-radius: 4px;
}

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

.prev:hover, .next:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

.caption-container {
    text-align: center;
    color: #ccc;
    padding: 15px;
    font-size: 16px;
    width: 100%;
}

@media only screen and (max-width: 600px) {
    .gallery-grid {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
        gap: 5px;
        padding: 5px;
    }
    
    .gallery-item img, 
    .gallery-item video {
        height: 140px;
    }
    
    .play-icon {
        font-size: 30px;
    }
    
    #lightbox-youtube {
        width: 95vw;
        height: 53vw;
    }
}

.pdf-btn {
    display: inline-block;
    margin: 15px 10px 5px 10px; 
    padding: 10px 20px;
    background-color: #2E7D32;
    color: white;
    text-decoration: none;
    font-weight: bold;
    border-radius: 6px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    transition: background-color 0.3s, transform 0.2s;
    font-size: 0.95rem;
}

.pdf-btn:hover {
    background-color: #1b5e20;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.3);
}

@media only screen and (max-width: 600px) {
    .pdf-btn {
        width: 90%;
        margin-top: 10px;
    }
}