:root {
    --bg-color: #020617;
    --accent-color: #38bdf8;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --glass-bg: rgba(15, 23, 42, 0.6);
    --glass-border: rgba(255, 255, 255, 0.05);
    --transition-smooth: all 0.5s cubic-bezier(0.23, 1, 0.32, 1);
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    overflow-x: hidden;
}

/* Custom Scrollbar for immersive experience */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: transparent; 
}

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.15); 
    border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3); 
}

/* Firefox scrollbar support */
* {
    scrollbar-width: thin;
    scrollbar-color: rgba(255, 255, 255, 0.15) transparent;
}

/* Header & Navigation */
header {
    padding: 2rem 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    background: rgba(2, 6, 23, 0.8);
    backdrop-filter: blur(20px);
    z-index: 1000;
}

.brand {
    font-size: 1.8rem;
    font-weight: 900;
    letter-spacing: -1px;
    background: linear-gradient(135deg, #fff 0%, var(--accent-color) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.filters {
    display: flex;
    gap: 1rem;
}

.filter-btn {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-secondary);
    padding: 0.5rem 1.2rem;
    border-radius: 50px;
    cursor: pointer;
    transition: var(--transition-smooth);
    font-size: 0.9rem;
}

.filter-btn.active, .filter-btn:hover {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
    box-shadow: 0 0 20px rgba(56, 189, 248, 0.3);
}

/* Masonry/Waterfall Layout */
.gallery-container {
    padding: 2rem 5%;
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
}

.gallery-item {
    position: relative;
    border-radius: 20px;
    overflow: hidden;
    cursor: pointer;
    background: var(--glass-bg);
    transition: var(--transition-smooth);
}

.gallery-item:hover {
    transform: scale(1.02);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
}

.gallery-item img {
    width: 100%;
    height: auto;
    display: block;
    transition: var(--transition-smooth);
    animation: imageFadeIn 0.8s ease-out;
}

@keyframes imageFadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.gallery-item:hover img {
    filter: brightness(0.7);
}

.item-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 1.5rem;
    background: linear-gradient(to top, rgba(0,0,0,0.8) 0%, transparent 100%);
    opacity: 0;
    transform: translateY(20px);
    transition: var(--transition-smooth);
}

.gallery-item:hover .item-overlay {
    opacity: 1;
    transform: translateY(0);
}

.item-title {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 0.3rem;
}

.item-category {
    font-size: 0.8rem;
    color: var(--accent-color);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Lightbox Styling */
.lightbox {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.95);
    backdrop-filter: blur(15px);
    display: none;
    z-index: 2000;
    justify-content: center;
    align-items: center;
}

.lightbox.active {
    display: flex;
    animation: fadeIn 0.4s ease;
}

.lightbox-content {
    max-width: 90%;
    max-height: 90%;
    display: flex;
    gap: 2rem;
    position: relative;
}

.lightbox-img-container {
    flex: 2;
    display: flex;
    align-items: center;
    justify-content: center;
}

.lightbox-img-container img {
    max-width: 100%;
    max-height: 80vh;
    border-radius: 12px;
    box-shadow: 0 0 50px rgba(0,0,0,0.5);
}

.lightbox-info {
    flex: 1;
    color: var(--text-primary);
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.info-title { font-size: 2rem; font-weight: 800; margin-bottom: 1rem; }
.info-desc { color: var(--text-secondary); line-height: 1.6; margin-bottom: 2rem; }
.info-meta { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.meta-item { background: var(--glass-bg); padding: 1rem; border-radius: 12px; border: 1px solid var(--glass-border); }
.meta-label { font-size: 0.7rem; color: var(--text-secondary); text-transform: uppercase; margin-bottom: 0.3rem; }
.meta-value { font-size: 1rem; font-weight: 600; }
.tags-display { display: flex; flex-wrap: wrap; gap: 5px; }
.mini-tag { 
    font-size: 0.75rem; 
    background: rgba(255,255,255,0.1); 
    padding: 2px 8px; 
    border-radius: 4px; 
    color: var(--text-primary);
    border: 1px solid rgba(255,255,255,0.1);
}

.close-lightbox {
    position: absolute;
    top: -40px;
    right: 0;
    font-size: 2rem;
    cursor: pointer;
    color: var(--text-secondary);
}

@keyframes fadeIn {
    from { opacity: 0; transform: scale(0.95); }
    to { opacity: 1; transform: scale(1); }
}

/* Responsive */
@media (max-width: 1024px) {
    .lightbox-content { flex-direction: column; overflow-y: auto; padding: 2rem; }
}

@media (max-width: 768px) {
    header {
        flex-direction: column;
        align-items: flex-start;
        padding: 1.5rem 5%;
        gap: 1.2rem;
    }

    .brand {
        font-size: 1.5rem;
    }

    .filters {
        width: 100%;
        overflow-x: auto;
        padding-bottom: 5px;
        -webkit-overflow-scrolling: touch;
        gap: 0.8rem;
        scrollbar-width: none; /* Hide scrollbar Firefox */
    }

    .filters::-webkit-scrollbar {
        display: none; /* Hide scrollbar Chrome/Safari */
    }

    .filter-btn {
        white-space: nowrap;
        padding: 0.4rem 1rem;
        font-size: 0.85rem;
        flex-shrink: 0;
    }
}

/* Footer Styles */
footer {
    padding: 60px 5% 40px;
    margin-top: 4rem;
    border-top: 1px solid var(--glass-border);
    text-align: center;
    background: linear-gradient(to bottom, transparent, rgba(15, 23, 42, 0.3));
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

#footerInfo {
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

#beianInfo {
    color: var(--text-secondary);
    font-size: 0.85rem;
    letter-spacing: 0.5px;
    text-decoration: none;
    transition: var(--transition-smooth);
}

#beianInfo:hover {
    color: var(--accent-color);
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: rgba(15, 23, 42, 0.7);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(56, 189, 248, 0.3);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-color);
    cursor: pointer;
    z-index: 1500;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--accent-color);
    color: #fff;
    box-shadow: 0 0 20px rgba(56, 189, 248, 0.5);
    transform: scale(1.1);
}

/* Enhanced Responsive Layout */
@media (min-width: 1801px) {
    .gallery-container, footer, header {
        max-width: 1800px;
        margin-left: auto !important;
        margin-right: auto !important;
    }
}

@media (max-width: 1024px) {
    .gallery-container {
        gap: 1rem;
        padding: 1rem 3%;
    }
}

@media (max-width: 480px) {
    .gallery-container {
        padding: 0.5rem 2%;
        gap: 0.8rem;
    }
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 44px;
        height: 44px;
    }
}