.space-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100vw;
    height: 123vh;
    background: radial-gradient(ellipse at center, #0a001f 0%, #000000 80%);
    overflow: hidden;
    z-index: -1;
}

.star {
    position: absolute;
    width: 2px;
    height: 2px;
    background: white;
    border-radius: 50%;
    opacity: 0.8;
    animation: twinkle 3s infinite ease-in-out alternate;
    filter: drop-shadow(0 0 2px white);
}

.planet {
    position: absolute;
    bottom: 0%;
    left: 50%;
    transform: translateX(-50%);
    width: 120vw;
    height: 23vw;
    max-height: 400px;
    background: #0D0D0D;
    border-radius: 60% 60% 0 0 / 100% 100% 0 0;
    z-index: 1;
    box-shadow:
            0 -20px 60px 10px rgba(255, 255, 255, 0.35),
            inset 0 20px 60px 10px rgba(255, 255, 255, 0.25);
}

.planet::after {
    content: "";
    position: absolute;
    top: -3px;
    left: 50%;
    transform: translateX(-50%);
    width: 100%;
    height: 100%;
    border-top: 2.5px solid white;
    border-radius: 60% 60% 0 0 / 100% 100% 0 0;
    mask-image: linear-gradient(to right, transparent 0%, white 40%, white 60%, transparent 100%);
    pointer-events: none;
    z-index: 2;
}

@keyframes twinkle {
    0% { opacity: 0.3; transform: scale(0.8); }
    100% { opacity: 1; transform: scale(1.2); }
}

.nebula {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.5;
    mix-blend-mode: screen;
    animation: nebulaMove 15s ease-in-out infinite alternate;
}

.nebula1 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, #9b59b6 0%, transparent 70%);
    top: 10%;
    left: 15%;
    animation-delay: 0s;
}

.nebula2 {
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, #8e44ad 0%, transparent 70%);
    top: 50%;
    left: 65%;
    animation-delay: 5s;
}

.nebula3 {
    width: 350px;
    height: 350px;
    background: radial-gradient(circle, #663399 0%, transparent 70%);
    top: 75%;
    left: 35%;
    animation-delay: 10s;
}

@keyframes nebulaMove {
    0% {
        transform: translate(0, 0) scale(1);
        opacity: 0.5;
    }
    100% {
        transform: translate(20px, -20px) scale(1.05);
        opacity: 0.6;
    }
}