:root {
    /* Colors */
    --primary-color: #6a0572; /* Deep Purple */
    --secondary-color: #fca311; /* Vibrant Orange */
    --accent-color: #1a759f; /* Deep Sky Blue */
    --text-color: #333;
    --light-text-color: #555;
    --background-color: #f8f8f8;
    --card-background: #fff;
    --border-color: #ddd;
    --success-color: #28a745;
    --error-color: #dc3545;

    /* Fonts */
    --font-family-sans: 'Helvetica Neue', Helvetica, Arial, sans-serif;
    --font-family-serif: 'Georgia', serif;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;

    /* Border Radius */
    --border-radius: 8px;
}

body {
    font-family: var(--font-family-sans);
    line-height: 1.6;
    margin: 0;
    padding: 0;
    background-color: var(--background-color);
    color: var(--text-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

/* Header */
header {
    background-color: var(--primary-color);
    color: #fff;
    padding: var(--spacing-md) 0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

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

.logo {
    margin: 0;
    font-size: 1.8rem;
    font-weight: bold;
}

header nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-wrap: wrap;
}

header nav ul li {
    margin-left: var(--spacing-lg);
}

header nav ul li a {
    color: #fff;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

header nav ul li a:hover {
    color: var(--secondary-color);
}

/* Hero Section */
.hero {
    background: linear-gradient(rgba(0,0,0,0.5), rgba(0,0,0,0.5)), url('https://images.unsplash.com/photo-1516762689617-e1cffcef479d?q=80&w=2070&auto=format&fit=crop&ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D') no-repeat center center/cover;
    color: #fff;
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-sm);
    border-radius: var(--border-radius);
    margin-top: var(--spacing-lg);
}

.hero h2 {
    font-size: 2.8rem;
    margin-bottom: var(--spacing-sm);
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-lg);
}

/* Buttons */
.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: bold;
    cursor: pointer;
    border: none;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.btn.primary {
    background-color: var(--secondary-color);
    color: var(--primary-color);
}

.btn.primary:hover {
    background-color: #e0920f;
}

.btn.secondary {
    background-color: transparent;
    color: #fff;
    border: 2px solid #fff;
    margin-left: var(--spacing-sm);
}

.btn.secondary:hover {
    background-color: #fff;
    color: var(--primary-color);
}

.btn.small {
    padding: 0.4rem 0.8rem;
    font-size: 0.9rem;
}

/* Sections */
section {
    padding: var(--spacing-xl) 0;
    margin-bottom: var(--spacing-lg);
}

section h2 {
    text-align: center;
    font-size: 2.2rem;
    margin-bottom: var(--spacing-lg);
    color: var(--primary-color);
}

/* Listings Grid */
.listings-section .filters {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    justify-content: center;
    flex-wrap: wrap;
}

.listings-section .filters input,
.listings-section .filters select {
    padding: var(--spacing-xs) var(--spacing-sm);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    flex-grow: 1;
    max-width: 250px;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.listing-card {
    background-color: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 10px rgba(0,0,0,0.05);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    flex-direction: column;
}

.listing-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 15px rgba(0,0,0,0.1);
}

.listing-card img {
    width: 100%;
    height: 250px;
    object-fit: cover;
    display: block;
    background-color: #eee; /* Placeholder background */
}

.listing-card-content {
    padding: var(--spacing-md);
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.listing-card h3 {
    margin-top: 0;
    margin-bottom: var(--spacing-xs);
    font-size: 1.4rem;
    color: var(--primary-color);
}

.listing-card p {
    font-size: 0.95rem;
    color: var(--light-text-color);
    margin-bottom: var(--spacing-sm);
    flex-grow: 1;
}

.listing-card .price {
    font-size: 1.3rem;
    font-weight: bold;
    color: var(--secondary-color);
    margin-top: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.listing-card .buy-btn {
    background-color: var(--accent-color);
    color: #fff;
    text-align: center;
    padding: var(--spacing-sm);
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: bold;
    transition: background-color 0.3s ease;
    margin-top: auto; /* Push button to bottom */
}

.listing-card .buy-btn:hover {
    background-color: #155e80;
}


/* Forms */
.form {
    max-width: 600px;
    margin: 0 auto;
    background-color: var(--card-background);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 10px rgba(0,0,0,0.05);
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: bold;
    color: var(--light-text-color);
}

.form-group input[type="text"],
.form-group input[type="email"],
.form-group input[type="number"],
.form-group input[type="url"],
.form-group textarea,
.form-group select {
    width: calc(100% - 20px); /* Account for padding */
    padding: var(--spacing-sm);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    box-sizing: border-box; /* Include padding in width */
}

.form-group textarea {
    resize: vertical;
}

.form button[type="submit"] {
    width: 100%;
    padding: var(--spacing-md);
    font-size: 1.1rem;
}

.message {
    margin-top: var(--spacing-md);
    padding: var(--spacing-sm);
    border-radius: var(--border-radius);
    text-align: center;
    font-weight: bold;
}

.message.success {
    background-color: #d4edda;
    color: var(--success-color);
    border: 1px solid #c3e6cb;
}

.message.error {
    background-color: #f8d7da;
    color: var(--error-color);
    border: 1px solid #f5c6cb;
}

/* About Section */
.about-section p {
    max-width: 800px;
    margin: var(--spacing-md) auto;
    text-align: center;
    color: var(--light-text-color);
}

/* Footer */
footer {
    background-color: var(--primary-color);
    color: #fff;
    text-align: center;
    padding: var(--spacing-md) 0;
    margin-top: var(--spacing-xl);
}

footer p {
    margin: var(--spacing-xs) 0;
}

/* Loading Skeletons */
.loading-grid .listing-card.loading {
    background-color: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 10px rgba(0,0,0,0.05);
    overflow: hidden;
    position: relative;
    height: 400px; /* Approximate height of a card */
}

.loading-grid .listing-card.loading::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: loading 1.5s infinite;
}

.loading-grid .listing-card.loading img,
.loading-grid .listing-card.loading h3,
.loading-grid .listing-card.loading p,
.loading-grid .listing-card.loading .price,
.loading-grid .listing-card.loading .buy-btn {
    visibility: hidden; /* Hide actual content */
}

.loading-text .loading {
    height: 1.2em;
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: loading 1.5s infinite;
    margin: var(--spacing-sm) auto;
    border-radius: 4px;
}

.loading-text .loading:nth-child(1) { width: 70%; }
.loading-text .loading:nth-child(2) { width: 80%; }
.loading-text .loading:nth-child(3) { width: 60%; }

@keyframes loading {
    0% { background-position: -200% 0; }
    100% { background-position: 200% 0; }
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    header .container {
        flex-direction: column;
        text-align: center;
    }

    header nav ul {
        margin-top: var(--spacing-sm);
        justify-content: center;
    }

    header nav ul li {
        margin: 0 var(--spacing-sm);
    }

    .hero h2 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 1rem;
    }

    .btn.secondary {
        margin-left: 0;
        margin-top: var(--spacing-sm);
    }

    .listings-section .filters {
        flex-direction: column;
        align-items: center;
    }

    .listings-section .filters input,
    .listings-section .filters select,
    .listings-section .filters button {
        width: 100%;
        max-width: 300px;
    }

    .grid {
        grid-template-columns: 1fr;
    }

    .form {
        padding: var(--spacing-md);
    }
}

@media (max-width: 480px) {
    .logo {
        font-size: 1.5rem;
    }

    header nav ul li {
        margin: 0 var(--spacing-xs);
    }

    .hero {
        padding: var(--spacing-lg) var(--spacing-sm);
    }

    .hero h2 {
        font-size: 1.8rem;
    }

    .btn {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: 0.9rem;
    }

    section h2 {
        font-size: 1.8rem;
    }
}