/* --- General Styles & Dark Mode --- */
:root {
    --bg-color: #121212;
    --surface-color: #1e1e1e;
    --primary-text: #e0e0e0;
    --secondary-text: #a0a0a0;
    --accent-color: #4CAF50; /* A nice, natural green */
    --border-color: #333333;
}

body {
    background-color: var(--bg-color);
    color: var(--primary-text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    margin: 0;
    padding: 2rem;
}

/* --- Header --- */
.header {
    text-align: center;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1.5rem;
    margin-bottom: 2rem;
}

.header h1 {
    margin: 0;
    font-size: 2.5rem;
    font-weight: 300;
    letter-spacing: 2px;
}

/* --- Gallery Grid --- */
.gallery-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.5rem;
    max-width: 1200px;
    margin: 0 auto;
}

/* --- Tree Card Thumbnail --- */
.tree-card {
    background-color: var(--surface-color);
    border-radius: 8px;
    overflow: hidden;
    text-decoration: none;
    color: var(--primary-text);
    border: 1px solid var(--border-color);
    transition: transform 0.2s ease-in-out, box-shadow 0.2s ease-in-out;
}

.tree-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.5);
}

.tree-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
}

.tree-card a {
    text-decoration: none;
}

.tree-card h3 {
    margin: 0;
    padding: 1rem;
    font-weight: 400;
    text-align: center;
    color: var(--secondary-text, #a0a0a0);
}