/* ==========================================================================
   BTF BACKGROUND ENGINE
   Stripped from SN 2026 — grainient + conical light rays only.
   ========================================================================== */

.btf-bg-engine {
    background-color: #030305 !important;
    position: absolute;
    inset: 0;
    z-index: 1;
    overflow: hidden;
    pointer-events: none;
}

/* THE CANVAS: Base configuration */
.btf-bg-canvas {
    display: block !important;
    position: absolute;
    top: -10%;
    left: -10%;
    width: 120% !important;
    height: 120% !important;
    opacity: 0;
    transition: opacity 1.5s ease-in;
    pointer-events: none;
}

/* Conical Light Rays — medium blur for beam definition */
.btf-bg-canvas--light_rays {
    z-index: 5 !important;
    filter: blur(20px) !important;
    transform: scale(1.1) translateY(-2%) translateZ(0) !important;
    mix-blend-mode: screen;
    will-change: transform, filter;
}

/* Fade in when JS is ready */
.btf-bg-canvas.is-ready {
    opacity: 1 !important;
}

/* Center Glow — pulsating city-color radial */
.btf-engine-glow {
    position: absolute;
    inset: 0;
    z-index: 10;
    background: radial-gradient(circle at 50% 45%, rgba(var(--blue-rgb), var(--glow-opacity, 0.45)) 0%, transparent 65%);
    mix-blend-mode: screen;
    animation: btfGlowPulse 8s ease-in-out infinite;
}

@keyframes btfGlowPulse {
    0%, 100% { transform: scale(1); opacity: 0.6; }
    50% { transform: scale(1.1); opacity: 0.9; }
}

/* Dark Overlay — opacity controlled inline by background-engine.php */
.btf-engine-overlay {
    position: absolute;
    inset: 0;
    z-index: 5;
}

/* ==========================================================================
   GRAINIENT MODE (Animated Mesh + SVG Grain)
   ========================================================================== */

.btf-bg-mode-grainient {
    background: #030305 !important;
}

/* Grain Texture Overlay */
.btf-bg-mode-grainient::before {
    content: "";
    position: absolute;
    inset: -100%;
    z-index: 2;
    background: #fff;
    filter: url(#grain-filter);
    opacity: var(--grain-opacity, 0.1);
    pointer-events: none;
}

/* Shifting Mesh */
.btf-bg-canvas--grainient {
    filter: blur(140px) !important;
    opacity: 0.6 !important;
    background-color: var(--aurora-color-1) !important;
    background-image:
        radial-gradient(at 10% 10%, var(--aurora-color-2) 0px, transparent 50%),
        radial-gradient(at 90% 10%, var(--aurora-color-3) 0px, transparent 50%),
        radial-gradient(at 50% 50%, var(--aurora-color-2) 0px, transparent 50%),
        radial-gradient(at 10% 90%, var(--aurora-color-3) 0px, transparent 50%),
        radial-gradient(at 90% 90%, var(--aurora-color-2) 0px, transparent 50%) !important;
    background-size: 200% 200% !important;
    animation: btfGrainientShift var(--gradient-speed, 12s) ease-in-out infinite alternate !important;
    transform: scale(1.4) !important;
}

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

/* ==========================================================================
   MOBILE OVERRIDES
   ========================================================================== */
@media (max-width: 991px) {
    .btf-bg-canvas {
        top: 0 !important;
        left: 0 !important;
        width: 100% !important;
        height: 100% !important;
        transform: none !important;
    }

    .btf-bg-canvas--light_rays {
        filter: blur(12px) !important;
    }
}