.split-bg-container {
    position: fixed;
    inset: 0;
    z-index: -1;
    overflow: hidden;
    pointer-events: none;
    isolation: isolate;
}

.split-bg-half {
    position: absolute;
    top: -2%;
    bottom: -2%;
    width: 50%;
}

.split-bg-half--left {
    left: 0;
    background: linear-gradient(90deg, #0000ff 0%, #0000ff 72%, rgba(0, 0, 255, 0.7) 100%);
}

.split-bg-half--right {
    right: 0;
    background: linear-gradient(270deg, #ff0000 0%, #ff0000 72%, rgba(255, 0, 0, 0.7) 100%);
}

.split-bg-seam {
    position: absolute;
    top: 0;
    left: 50%;
    width: clamp(360px, 50vw, 920px);
    height: 100%;
    transform: translateX(-50%);
    filter: blur(16px) saturate(128%) brightness(1.05);
    opacity: 1;
}

.split-bg-seam::before,
.split-bg-seam::after {
    content: "";
    position: absolute;
    inset: 0;
}

.split-bg-seam::before {
    background:
        linear-gradient(
            90deg,
            rgba(0, 0, 255, 0.08) 0%,
            rgba(0, 0, 255, 0.16) 24%,
            rgba(255, 255, 255, 0.12) 50%,
            rgba(255, 0, 0, 0.16) 76%,
            rgba(255, 0, 0, 0.08) 100%
        );
}

.split-bg-seam::after {
    background:
        radial-gradient(circle at center, rgba(255, 255, 255, 0.18), transparent 62%),
        linear-gradient(90deg, rgba(0, 0, 255, 0.16), transparent 32%, transparent 68%, rgba(255, 0, 0, 0.16));
    filter: blur(34px);
}

.split-bg-seam-canvas {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 0.65s ease-in-out;
}

.split-bg-seam-canvas.is-visible {
    opacity: 1;
}