:root {
    --bg-color: #0f172a;
    --text-color: #f8fafc;
    --accent-color: #38bdf8;
    --card-bg: rgba(30, 41, 59, 0.7);
    --overlay-bg: rgba(0, 0, 0, 0.6);
    --transition-speed: 0.3s;
}

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

body {
    font-family: 'Outfit', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    overflow-x: hidden;
}

.background-gradient {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 15% 50%, rgba(56, 189, 248, 0.15), transparent 25%),
        radial-gradient(circle at 85% 30%, rgba(139, 92, 246, 0.15), transparent 25%);
    z-index: -1;
    pointer-events: none;
}

header {
    text-align: center;
    padding: 3rem 1rem;
    animation: fadeInDown 0.8s ease-out;
}

h1 {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    background: linear-gradient(to right, #38bdf8, #818cf8);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.subtitle {
    color: #94a3b8;
    font-size: 1.1rem;
}

.email {
    margin-top: 0.5rem;
    font-size: 1rem;
}

.email a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.2s;
}

.email a:hover {
    color: #818cf8;
    text-decoration: underline;
}

main {
    width: 100%;
    max-width: 1200px;
    padding: 0 2rem 4rem;
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2rem;
    width: 100%;
}

.gallery-item {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    cursor: pointer;
    background: var(--card-bg);
    border: 1px solid rgba(255, 255, 255, 0.05);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
    aspect-ratio: 4/3;
    /* Standard certificate ratio */
    animation: fadeInUp 0.6s ease-out backwards;
}

/* Staggered animation for items */
.gallery-item:nth-child(1) {
    animation-delay: 0.1s;
}

.gallery-item:nth-child(2) {
    animation-delay: 0.2s;
}

.gallery-item:nth-child(3) {
    animation-delay: 0.3s;
}

.gallery-item:nth-child(4) {
    animation-delay: 0.4s;
}

.gallery-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.2), 0 10px 10px -5px rgba(0, 0, 0, 0.1);
    border-color: rgba(56, 189, 248, 0.3);
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.gallery-item:hover img {
    transform: scale(1.05);
}

.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 23, 42, 0.6);
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0;
    transition: opacity var(--transition-speed);
    backdrop-filter: blur(2px);
}

.gallery-item:hover .overlay {
    opacity: 1;
}

.overlay span {
    color: white;
    font-weight: 600;
    padding: 0.75rem 1.5rem;
    border: 1px solid white;
    border-radius: 9999px;
    transform: translateY(10px);
    transition: transform var(--transition-speed);
}

.gallery-item:hover .overlay span {
    transform: translateY(0);
}

/* Lightbox */
.lightbox {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.9);
    backdrop-filter: blur(8px);
    justify-content: center;
    align-items: center;
    flex-direction: column;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.lightbox.active {
    display: flex;
    opacity: 1;
}

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

#lightboxImg {
    max-width: 100%;
    max-height: 85vh;
    border-radius: 8px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    object-fit: contain;
}

.close-btn {
    position: absolute;
    top: 20px;
    right: 30px;
    color: #f1f1f1;
    font-size: 40px;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.2s;
    z-index: 1001;
}

.close-btn:hover {
    color: var(--accent-color);
}

.nav-btn {
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: white;
    font-size: 2rem;
    padding: 1rem;
    cursor: pointer;
    border-radius: 50%;
    transition: background 0.2s, transform 0.2s;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 60px;
    height: 60px;
}

.nav-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-50%) scale(1.1);
}

.prev-btn {
    left: -80px;
}

.next-btn {
    right: -80px;
}

.caption {
    margin-top: 1rem;
    color: #ccc;
    font-size: 1.2rem;
    text-align: center;
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .nav-btn {
        position: fixed;
        top: auto;
        bottom: 20px;
        transform: none;
        background: rgba(0, 0, 0, 0.5);
    }

    .nav-btn:hover {
        transform: scale(1.1);
    }

    .prev-btn {
        left: 20px;
    }

    .next-btn {
        right: 20px;
    }

    .lightbox-content {
        width: 100%;
    }

    #lightboxImg {
        max-width: 95%;
    }
}