body {
    min-height: 100vh;
    background: linear-gradient(135deg, #ff6b6b, #f7d358, #4ecdc4, #1a535c);
    background-size: 400% 400%;
    animation: gradientBG 15s ease infinite;
}

@keyframes gradientBG {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}