      background: radial-gradient(
                400px circle at var(--x, 50%) var(--y, 50%),
                rgba(167, 199, 255, 0.15),
                transparent 80%
            );
            z-index: 0;
            transition: background 0.1s ease-out;
        }
        html.light-mode body::before {
             background: radial-gradient(
                400px circle at var(--x, 50%) var(--y, 50%),
                rgba(0, 113, 227, 0.1),
                transparent 80%
            );
