/* ========================================
   Image Gallery Styles - FIXED VERSION
   Grid Layout (Row-based) + Lightbox
   修复：从瀑布流改为行优先的网格布局
   ======================================== */

/* ========================================
   Gallery Container
   ======================================== */
.gallery-section {
    padding: var(--spacing-lg) var(--spacing-md);
    max-width: 1600px;
    margin: 0 auto;
}

/* ========================================
   Masonry Grid Layout - 行优先排列（从左到右，从上到下）
   ======================================== */
.masonry-grid {
    /* 使用 CSS Grid 代替 column-count */
    display: grid;
    /* 使用固定列数：4列 */
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    /* 关键：按行填充（从左到右，从上到下）- 这是最重要的属性 */
    grid-auto-flow: row;
    /* 确保网格对齐正确 */
    justify-items: stretch;
    align-items: stretch;
    /* 防止网格项被重新排序 */
    unicode-bidi: plaintext;
}

/* 确保所有网格项按DOM顺序显示 */
.masonry-grid > * {
    order: 0;
}

.masonry-item {
    position: relative;
    overflow: hidden;
    background: var(--color-gray-dark);
    cursor: pointer;
    /* 设置统一高度以保证整齐排列 */
    aspect-ratio: 1 / 1;
}

.masonry-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: transform 0.4s ease, filter 0.3s ease;
}

.masonry-item:hover img {
    transform: scale(1.03);
}

/* Overlay on hover */
.masonry-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 20px;
    background: linear-gradient(transparent, rgba(0, 0, 0, 0.85));
    opacity: 0;
    transform: translateY(10px);
    transition: all 0.3s ease;
}

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

.masonry-title {
    font-size: 1rem;
    font-weight: 500;
    color: var(--color-white);
    margin-bottom: 4px;
}

.masonry-meta {
    font-size: 0.75rem;
    color: var(--color-accent-light);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

/* ========================================
   Standard Grid Layout (Alternative)
   ======================================== */
.standard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 16px;
}

.standard-grid .gallery-item {
    position: relative;
    aspect-ratio: 4/3;
    overflow: hidden;
    background: var(--color-gray-dark);
    cursor: pointer;
}

.standard-grid .gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
}

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

/* ========================================
   Lightbox
   ======================================== */
.lightbox {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.95);
    z-index: 9999;
    justify-content: center;
    align-items: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

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

.lightbox-content {
    position: relative;
    max-width: 90vw;
    max-height: 90vh;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.lightbox-image {
    max-width: 100%;
    max-height: 80vh;
    object-fit: contain;
    box-shadow: 0 0 50px rgba(0, 0, 0, 0.5);
}

.lightbox-info {
    margin-top: 20px;
    text-align: center;
    color: var(--color-white);
}

.lightbox-title {
    font-size: 1.25rem;
    font-weight: 400;
    margin-bottom: 8px;
}

.lightbox-description {
    font-size: 0.875rem;
    color: var(--color-gray-light);
    max-width: 600px;
}

/* Lightbox Controls */
.lightbox-close {
    position: absolute;
    top: 20px;
    right: 20px;
    width: 50px;
    height: 50px;
    background: transparent;
    border: 1px solid var(--color-gray);
    color: var(--color-white);
    font-size: 24px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    z-index: 10001;
}

.lightbox-close:hover {
    background: var(--color-white);
    color: var(--color-black);
}

.lightbox-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 50px;
    height: 80px;
    background: transparent;
    border: 1px solid var(--color-gray);
    color: var(--color-white);
    font-size: 24px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.lightbox-nav:hover {
    background: var(--color-white);
    color: var(--color-black);
}

.lightbox-prev {
    left: 20px;
}

.lightbox-next {
    right: 20px;
}

.lightbox-counter {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    color: var(--color-gray-light);
    font-size: 0.875rem;
}

/* ========================================
   Filter Tags
   ======================================== */
.gallery-filters {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--color-gray-dark);
}

.filter-btn {
    background: transparent;
    border: 1px solid var(--color-gray);
    color: var(--color-gray-light);
    padding: 8px 16px;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: inherit;
}

.filter-btn:hover,
.filter-btn.active {
    border-color: var(--color-accent);
    color: var(--color-white);
    background: rgba(107, 143, 143, 0.2);
}

/* ========================================
   Loading State
   ======================================== */
.gallery-loading {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--color-gray-light);
}

.gallery-loading::after {
    content: '';
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--color-gray);
    border-top-color: var(--color-accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-left: 10px;
    vertical-align: middle;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ========================================
   Empty State
   ======================================== */
.gallery-empty {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--color-gray-light);
}

.gallery-empty-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
    opacity: 0.3;
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 1200px) {
    .masonry-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 900px) {
    .masonry-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .lightbox-nav {
        width: 40px;
        height: 60px;
    }
    
    .lightbox-prev { left: 10px; }
    .lightbox-next { right: 10px; }
}

@media (max-width: 600px) {
    .masonry-grid {
        grid-template-columns: 1fr;
    }
    
    .gallery-section {
        padding: var(--spacing-md) var(--spacing-sm);
    }
    
    .lightbox-close {
        top: 10px;
        right: 10px;
        width: 40px;
        height: 40px;
    }
    
    .lightbox-info {
        padding: 0 15px;
    }
    
    .gallery-filters {
        justify-content: center;
    }
}

/* ========================================
   Animation Effects
   ======================================== */
.masonry-item {
    animation: fadeInUp 0.6s ease forwards;
    opacity: 0;
}

.masonry-item:nth-child(1) { animation-delay: 0.05s; }
.masonry-item:nth-child(2) { animation-delay: 0.1s; }
.masonry-item:nth-child(3) { animation-delay: 0.15s; }
.masonry-item:nth-child(4) { animation-delay: 0.2s; }
.masonry-item:nth-child(5) { animation-delay: 0.25s; }
.masonry-item:nth-child(6) { animation-delay: 0.3s; }
.masonry-item:nth-child(7) { animation-delay: 0.35s; }
.masonry-item:nth-child(8) { animation-delay: 0.4s; }
.masonry-item:nth-child(n+9) { animation-delay: 0.45s; }

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Lightbox fade animations */
.lightbox-image {
    animation: zoomIn 0.3s ease;
}

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