/* CSS Variables */
:root {
    /* Background Colors */
    --bg-color: #1c1c1c;
    --gallery-item-bg: rgba(255, 255, 255, 1);
    --video-bg: transparent;
    --lightbox-bg: rgba(0, 0, 0, 0.9);
    --video-overlay-bg: rgba(255, 255, 255, 0.95);
    --video-overlay-bg-hover: rgba(255, 255, 255, 1);
    --nav-btn-bg: rgba(255, 255, 255, 0.2);
    --nav-btn-bg-hover: rgba(255, 255, 255, 0.3);
    
    /* Timing Durations */
    --transition-fast: 100ms;
    --transition-normal: 0.2s;
    --transition-medium: 0.3s;
    --transition-slow: 0.8s;
    --lightbox-fade-duration: 300ms;
    --lightbox-zoom-duration: 300ms;
    --spinner-duration: 0.8s;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--bg-color);
    color: #333;
    line-height: 1.6;
}

.container {
    margin: 0 auto;
    padding: 5px;
}

.gallery {
    position: relative;
    width: 100%;
}

.gallery-item {
    position: absolute;
    width: 100%;
    margin-bottom: 15px;
    cursor: pointer;
    transition: left var(--transition-normal) cubic-bezier(0.4, 0, 0.2, 1), 
                top var(--transition-normal) cubic-bezier(0.4, 0, 0.2, 1), 
                width var(--transition-normal) cubic-bezier(0.4, 0, 0.2, 1),
                transform var(--transition-medium) ease,
                box-shadow var(--transition-medium) ease;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    background-color: var(--gallery-item-bg);
    border-radius: 3px;
}

.gallery-item:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
    z-index: 10;
}

.gallery-item img {
    width: 100%;
    height: auto;
    display: block;
    transition: opacity var(--transition-fast) ease;
}

.gallery-item video {
    width: 100%;
    height: auto;
    display: block;
    object-fit: contain;
    transition: opacity var(--transition-fast) ease;
}

.gallery-item:hover img,
.gallery-item:hover video {
    opacity: 0.9;
}

.gallery-item video {
    background-color: var(--video-bg);
}

.video-overlay {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 70px;
    height: 70px;
    background-color: var(--video-overlay-bg);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    pointer-events: none;
    transition: transform var(--transition-medium) ease, background-color var(--transition-medium) ease;
    z-index: 2;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.gallery-item:hover .video-overlay {
    transform: translate(-50%, -50%) scale(1.1);
    background-color: var(--video-overlay-bg-hover);
}

.video-overlay::before {
    content: '';
    width: 0;
    height: 0;
    border-left: 20px solid #333;
    border-top: 12px solid transparent;
    border-bottom: 12px solid transparent;
    margin-left: 4px;
}

/* Lightbox Styles */
.lightbox {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: var(--lightbox-bg);
    animation: fadeIn var(--lightbox-fade-duration) ease;
}

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

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.lightbox-image,
.lightbox-video {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    border-radius: 4px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
    animation: zoomIn var(--lightbox-zoom-duration) ease;
}

.lightbox-video {
    background-color: var(--video-bg);
}

@keyframes zoomIn {
    from {
        transform: scale(0.9);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

.close-btn {
    position: absolute;
    top: 10px;
    right: 10px;
    color: rgba(255, 255, 255, .3);
    font-size: 40px;
    font-weight: medium;
    cursor: pointer;
    transition: color var(--transition-medium) ease;
    z-index: 1001;
    line-height: 1;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.close-btn:hover {
    color: #ccc;
}

.nav-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background-color: var(--nav-btn-bg);
    color: #fff;
    border: none;
    font-size: 30px;
    padding: 15px 20px;
    cursor: pointer;
    transition: all var(--transition-medium) ease;
    border-radius: 4px;
    opacity: 0.3;
    z-index: 1001;
}

.nav-btn:hover {
    background-color: var(--nav-btn-bg-hover);
    opacity: .8;
}

.prev-btn {
    left: 20px;
}

.next-btn {
    right: 20px;
}

/* Lightbox Loader */
.lightbox-loader {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 1002;
    display: none;
}

.lightbox-loader.active {
    display: block;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top: 4px solid #fff;
    border-radius: 50%;
    animation: spin var(--spinner-duration) linear infinite;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }
    
    .gallery-item {
        margin-bottom: 10px;
    }
    
    .close-btn {
        top: 10px;
        right: 15px;
        font-size: 30px;
    }
    
    .nav-btn {
        font-size: 24px;
        padding: 10px 15px;
    }
    
    .prev-btn {
        left: 10px;
    }
    
    .next-btn {
        right: 10px;
    }
}