/* Theme Variables */
:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --bg-color: #ffffff;
    --font-color: #333333;
    --heading-color: #2c3e50;
}

[data-theme="dark"] {
    --primary-color: #ecf0f1;
    --secondary-color: #3498db;
    --bg-color: #1a1a2e;
    --font-color: #ecf0f1;
    --heading-color: #ecf0f1;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--font-color);
    line-height: 1.6;
    transition: background-color 0.3s, color 0.3s;
}

header {
    background-color: var(--primary-color);
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 100;
}

nav { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; }
.nav-brand { font-size: 1.5rem; font-weight: bold; color: white; }
.nav-links { display: flex; list-style: none; gap: 1.5rem; }
.nav-links a { color: white; text-decoration: none; padding: 0.5rem 1rem; border-radius: 4px; transition: background-color 0.3s; }
.nav-links a:hover, .nav-links a.active { background-color: var(--secondary-color); }

#themeToggle {
    background-color: var(--secondary-color);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    cursor: pointer;
}

main { max-width: 1200px; margin: 0 auto; padding: 2rem; }
section { margin-bottom: 3rem; padding: 2rem; background-color: var(--bg-color); border-radius: 8px; box-shadow: 0 2px 10px rgba(0,0,0,0.1); }

.welcome-section { text-align: center; background: linear-gradient(135deg, var(--secondary-color), var(--primary-color)); color: white; }
.welcome-section h1 { font-size: 2.5rem; margin-bottom: 0.5rem; }

h2 { color: var(--heading-color); margin-bottom: 1rem; }

.input-group { display: flex; gap: 0.5rem; justify-content: center; }
.input-group input { padding: 0.75rem; border: 2px solid var(--secondary-color); border-radius: 4px; font-size: 1rem; }
.input-group button { padding: 0.75rem 1.5rem; background-color: var(--secondary-color); color: white; border: none; border-radius: 4px; cursor: pointer; }

.gallery-buttons { display: flex; gap: 1rem; margin-bottom: 1rem; }
.gallery-buttons button { padding: 0.5rem 1rem; background-color: var(--primary-color); color: white; border: none; border-radius: 4px; cursor: pointer; }
.gallery-content img { max-width: 100%; height: auto; border-radius: 8px; margin-bottom: 1rem; }

footer { background-color: var(--primary-color); color: white; text-align: center; padding: 1.5rem; }
footer a { color: var(--secondary-color); }