body {
    background: linear-gradient(120deg, var(--bg-1), var(--bg-2), var(--bg-3), var(--bg-4));
    background-size: 300% 300%;
    animation: bg-drift 12s ease infinite;
    position: relative;
    overflow-x: hidden;
    transition: background 0.6s ease;
}

body::before {
    content: "";
    position: fixed;
    top: 50%;
    left: 50%;
    width: 800px;
    height: 800px;
    transform: translate(-50%, -50%);
    background: radial-gradient(circle, var(--glow-color), transparent 70%);
    animation: glow-pulse 6s ease-in-out infinite;
    pointer-events: none;
    z-index: -1;
}

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

@keyframes glow-pulse {
    0%, 100% { opacity: 0.6; transform: translate(-50%, -50%) scale(1); }
    50%      { opacity: 1;   transform: translate(-50%, -50%) scale(1.15); }
}