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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #f3c3f1 0%, #e7e1ee 100%);
    min-height: 100vh;
    padding: 40px 20px;
}

h1 {
    text-align: center;
    color: white;
    margin-bottom: 50px;
    font-size: 2.5rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.iframe-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    max-width: 1400px;
    margin: 0 auto;
}

.assignment-card {
    position: relative;
    overflow: hidden;
    border-radius: 12px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
    background: white;
}

.assignment-card:hover {
    box-shadow: 0 12px 48px rgba(0, 0, 0, 0.35);
}

.assignment-card a {
    display: block;
    text-decoration: none;
    color: inherit;
}

.assignment-label {
    padding: 15px;
    background: linear-gradient(135deg, #e29fd4 0%, #f18be9 100%);
    color: white;
    font-weight: 600;
    text-align: center;
    font-size: 0.95rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

iframe {
    width: 100%;
    height: 280px;
    border: none;
    display: block;
}

@media (max-width: 1024px) {
    .iframe-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 25px;
    }

    h1 {
        font-size: 2rem;
    }
}

@media (max-width: 600px) {
    .iframe-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    h1 {
        font-size: 1.5rem;
        margin-bottom: 30px;
    }

    iframe {
        height: 200px;
    }
}