:root {
    --primary-font: 'Roboto', sans-serif;
    --text-color: #333333;
    --text-light: #888888;
    --bg-color: #ffffff;
    --hover-bg: rgba(0, 0, 0, 0.8);
    --transition-speed: 0.3s;
}

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

body {
    font-family: var(--primary-font);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-speed);
}

.container {
    max-width: 1140px;
    margin: 0 auto;
    padding: 0 15px;
}

/* Header */
.site-header {
    padding: 30px 0;
    background: #fff;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    letter-spacing: 1px;
}

.logo span {
    font-weight: 400;
    color: var(--text-light);
}

.main-nav a {
    margin-left: 30px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-color);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.main-nav a:hover, .main-nav a.active {
    color: var(--text-light);
}

/* Page Heading */
.page-heading {
    margin-top: 60px;
    margin-bottom: 40px;
}

.page-heading h1 {
    font-size: 42px;
    font-weight: 400;
    color: #111;
    margin: 0;
}

/* Portfolio Filter */
.portfolio-filter {
    margin-bottom: 40px;
    display: flex;
    gap: 20px;
}

.portfolio-filter a {
    font-size: 14px;
    color: var(--text-light);
    font-weight: 500;
    padding-bottom: 5px;
}

.portfolio-filter a.active {
    color: var(--text-color);
    border-bottom: 2px solid var(--text-color);
}

/* Portfolio Grid */
.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 30px;
    margin-bottom: 60px;
}

.portfolio-item {
    position: relative;
    overflow: hidden;
    background: #f5f5f5; /* Light gray placeholder bg */
}

.portfolio-link {
    display: block;
    width: 100%;
    height: 100%;
    position: relative;
}

.portfolio-image-wrapper {
    width: 100%;
    /* To create a masonry-like varied height feel, we can just let the image dictate height, 
       but for placeholders we need a min-height */
    min-height: 300px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.portfolio-image-wrapper img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.5s ease;
}

.placeholder-img {
    width: 100%;
    height: 350px;
    background: #ececec;
    display: flex;
    align-items: center;
    justify-content: center;
}

.placeholder-img span {
    font-size: 48px;
    font-weight: 700;
    color: #d0d0d0;
}

/* Hover Overlay */
.portfolio-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--hover-bg);
    opacity: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity var(--transition-speed) ease;
}

.portfolio-link:hover .portfolio-overlay {
    opacity: 1;
}

.portfolio-link:hover .portfolio-image-wrapper img {
    transform: scale(1.03);
}

.portfolio-caption {
    text-align: center;
    color: #fff;
    transform: translateY(20px);
    transition: transform var(--transition-speed) ease;
}

.portfolio-link:hover .portfolio-caption {
    transform: translateY(0);
}

.portfolio-title {
    font-size: 20px;
    font-weight: 500;
    margin-bottom: 5px;
    letter-spacing: 0.5px;
}

.portfolio-desc {
    font-size: 13px;
    font-weight: 400;
    color: #cccccc;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Load More Button */
.load-more-container {
    text-align: center;
    margin-bottom: 100px;
}

.btn-load-more {
    display: inline-block;
    padding: 12px 35px;
    border: 1px solid #ddd;
    color: #333;
    font-size: 13px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1px;
    background: transparent;
    transition: all 0.3s ease;
}

.btn-load-more:hover {
    background: #333;
    color: #fff;
    border-color: #333;
}

/* Empty State */
.empty-state {
    padding: 50px 0;
    color: var(--text-light);
}

/* Responsive */
@media (max-width: 768px) {
    .header-inner {
        flex-direction: column;
        gap: 15px;
    }
    
    .main-nav a {
        margin: 0 15px;
    }
    
    .page-heading h1 {
        font-size: 32px;
    }
}