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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: #333333;
    background-color: #f8f9fa;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

header {
    text-align: center;
    padding: 20px;
    background-color: #ffffff;
    border-bottom: 1px solid #e0e0e0;
}

header img {
    height: 60px;
    width: auto;
    margin-bottom: 10px;
}

header h3 {
    font-size: 1.6rem;
    color: #1a252f;
    margin-bottom: 5px;
}

header p.subtitle {
    font-size: 0.85rem;
    color: #6c757d;
    letter-spacing: 0.5px;
    font-weight: 600;
}

.navbar {
    background-color: #1a252f;
    text-align: center;
    padding: 10px 0;
}

.navbar a.navtab {
    color: #ffffff;
    text-decoration: none;
    padding: 8px 16px;
    font-weight: 500;
    transition: background-color 0.2s ease;
}

.navbar a.navtab:hover {
    background-color: #34495e;
    border-radius: 4px;
}

.navbar span.sep {
    color: #7f8c8d;
}

.main-content {
    flex: 1;
    max-width: 1000px;
    width: 90%;
    margin: 30px auto;
    background: #ffffff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

.grid-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.card {
    border: 1px solid #e0e0e0;
    padding: 20px;
    border-radius: 6px;
    background-color: #fafafa;
}

.card h4 {
    color: #2c3e50;
    margin-bottom: 10px;
}

footer {
    background-color: #1a252f;
    color: #ffffff;
    text-align: center;
    padding: 15px 20px;
    font-size: 0.9rem;
}

footer h4 {
    font-weight: 400;
}