:root {
    --primary: #0b3d91;
    --accent: #ffcc00;
    --bg: #f5f7fa;
    --text: #222;
    --card-bg: #ffffff;
}

body.dark {
    --primary: #111827;
    --accent: #3b82f6;
    --bg: #0f172a;
    --text: #e5e7eb;
    --card-bg: #1f2937;
}

body {
    margin: 0;
    font-family: 'Segoe UI', Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    transition: background 0.4s ease, color 0.4s ease;
}

header {
    background: var(--primary);
    color: white;
    padding: 30px 0;
    text-align: center;
}

nav {
    display: flex;
    justify-content: center;
    gap: 30px;
    padding: 15px;
    background: #ffffff10;
    backdrop-filter: blur(8px);
}

nav a {
    text-decoration: none;
    color: var(--text);
    font-weight: 600;
    transition: 0.3s;
}

nav a:hover {
    color: var(--accent);
}

.hero {
    background: linear-gradient(120deg, var(--primary), #1e40af);
    color: white;
    padding: 120px 20px;
    text-align: center;
}

.container {
    max-width: 1100px;
    margin: 60px auto;
    padding: 0 20px;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.card {
    background: var(--card-bg);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 8px 25px rgba(0,0,0,0.08);
    transition: transform 0.4s ease, box-shadow 0.4s ease;
    opacity: 0;
    transform: translateY(30px);
}

.card.visible {
    opacity: 1;
    transform: translateY(0);
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 12px 35px rgba(0,0,0,0.15);
}

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

.card-body {
    padding: 25px;
}

footer {
    text-align: center;
    padding: 30px;
    background: var(--primary);
    color: white;
    margin-top: 60px;
}

.toggle-btn {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 10px 15px;
    background: var(--accent);
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-weight: bold;
}