/* ===========================
   COSMIC BACKGROUND - Shared
   Fundo com grid animado
   =========================== */

.cosmic-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: var(--z-behind, -1);
    overflow: hidden;
    background: linear-gradient(135deg, #0a0e1a 0%, #1a1a2e 50%, #0a0e1a 100%);
}

.grid-lines {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image:
        linear-gradient(rgba(0, 212, 255, 0.1) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 212, 255, 0.1) 1px, transparent 1px);
    background-size: 50px 50px;
    animation: gridMove 10s linear infinite;
}

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

/* ===========================
   PARTICLES
   =========================== */
.particles {
    position: absolute;
    width: 100%;
    height: 100%;
    overflow: hidden;
}

.particle {
    position: absolute;
    width: 2px;
    height: 2px;
    background: var(--neon-blue, #00D4FF);
    border-radius: 50%;
    opacity: 0.5;
    animation: float 20s infinite linear;
}

@keyframes float {
    0% {
        transform: translateY(100vh) rotate(0deg);
        opacity: 0;
    }
    10% {
        opacity: 0.5;
    }
    90% {
        opacity: 0.5;
    }
    100% {
        transform: translateY(-100vh) rotate(720deg);
        opacity: 0;
    }
}