:root {
    --bg-color: #f7f7f7;
    --text-color: #333;
    --accent-color: #007bff;
    --surface-color: #ffffff;
    --shadow-color: rgba(0, 0, 0, 0.05);
    --hover-shadow: rgba(0, 0, 0, 0.12);
    --gap: 16px;
}

:root[data-theme='dark'] {
    --bg-color: #0f1115;
    --text-color: #e6e6e6;
    --accent-color: #4da3ff;
    --surface-color: #1a1d23;
    --shadow-color: rgba(0, 0, 0, 0.6);
    --hover-shadow: rgba(0, 0, 0, 0.7);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

header {
    text-align: center;
    padding: 40px 20px;
    background-color: var(--surface-color);
    box-shadow: 0 2px 4px var(--shadow-color);
    margin-bottom: 20px;
}

h1 {
    margin: 0;
    font-weight: 300;
    letter-spacing: 1px;
}

.gallery {
    column-count: 1;
    column-gap: var(--gap);
    padding: 0 var(--gap);
    max-width: 1600px;
    margin: 0 auto;
}

@media (min-width: 600px) {
    .gallery {
        column-count: 2;
    }
}

@media (min-width: 900px) {
    .gallery {
        column-count: 3;
    }
}

@media (min-width: 1200px) {
    .gallery {
        column-count: 4;
    }
}

.gallery-item {
    break-inside: avoid;
    margin-bottom: var(--gap);
    position: relative;
    overflow: hidden;
    border-radius: 12px;
    transition: transform 0.4s cubic-bezier(0.165, 0.84, 0.44, 1), box-shadow 0.4s ease;
    cursor: zoom-in;
    opacity: 0;
    transform: translateY(30px);
}

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

.gallery-item:hover {
    transform: translateY(-6px) scale(1.02);
    box-shadow: 0 20px 40px var(--hover-shadow);
    z-index: 1;
}

.gallery-link {
    display: block;
    position: relative;
    text-decoration: none;
}

.placeholder {
    width: 100%;
    background-size: cover;
    background-position: center;
    filter: blur(10px);
    transform: scale(1.1);
    transition: opacity 0.5s ease;
}

.gallery-item img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    opacity: 0;
    transition: opacity 0.6s ease;
}

.gallery-item.loaded img {
    opacity: 1;
}

.gallery-item.loaded .placeholder {
    opacity: 0;
}

/* PhotoSwipe customization */
.pswp__bg {
    background: rgba(0, 0, 0, 0.9);
}