/* === SFONDO COSMICO === */
body {
    margin: 0;
    padding: 0;
    background: radial-gradient(circle at 50% 50%, #021024 0%, #000814 100%);
    color: #e0f4ff;
    font-family: 'Segoe UI', sans-serif;
    overflow: hidden;
}

/* === NUCLEO CENTRALE HO === */
#nucleo-ho {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 160px;
    height: 160px;
    transform: translate(-50%, -50%);
    border-radius: 50%;
    background: radial-gradient(circle, #27c4ff 0%, #003b5c 60%, #00111f 100%);
    box-shadow:
        0 0 25px rgba(0, 200, 255, 0.9),
        0 0 80px rgba(0, 120, 255, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
}

#nucleo-ho span {
    font-size: 34px;
    font-weight: 600;
    letter-spacing: 4px;
    color: #e9fbff;
    text-shadow: 0 0 12px rgba(0, 255, 255, 0.9);
}

/* === ORBITA === */
#orbita {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 520px;
    height: 520px;
    transform: translate(-50%, -50%);
    border-radius: 50%;
    animation: rotazione 60s linear infinite;
}

/* === SFERE ORBITALI === */
.sfera {
    position: absolute;
    width: 130px;
    height: 130px;
    border-radius: 50%;
    border: 1px solid rgba(120, 220, 255, 0.7);
    background: radial-gradient(circle, #0b2238 0%, #020814 80%);
    color: #dff6ff;
    font-size: 12px;
    letter-spacing: 1px;
    text-transform: uppercase;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 0 14px rgba(0, 200, 255, 0.7);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}

/* POSIZIONI */
.s1 { top: 0%;   left: 50%; transform: translate(-50%, -50%); }
.s2 { top: 18%;  left: 82%; transform: translate(-50%, -50%); }
.s3 { top: 50%;  left: 100%; transform: translate(-50%, -50%); }
.s4 { top: 82%;  left: 82%; transform: translate(-50%, -50%); }
.s5 { top: 100%; left: 50%; transform: translate(-50%, -50%); }
.s6 { top: 82%;  left: 18%; transform: translate(-50%, -50%); }
.s7 { top: 50%;  left: 0%;  transform: translate(-50%, -50%); }
.s8 { top: 18%;  left: 18%; transform: translate(-50%, -50%); }

/* HOVER */
.sfera:hover {
    background: radial-gradient(circle, #12345a 0%, #020814 80%);
    box-shadow:
        0 0 22px rgba(0, 255, 255, 0.9),
        0 0 60px rgba(0, 140, 255, 0.7);
    transform: translate(-50%, -50%) scale(1.06);
}

/* === HUD === */
#hud {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 520px;
    height: 340px;
    transform: translate(-50%, -50%);
    background: rgba(3, 12, 26, 0.92);
    border-radius: 14px;
    border: 1px solid rgba(120, 220, 255, 0.6);
    box-shadow:
        0 0 30px rgba(0, 200, 255, 0.7),
        0 0 90px rgba(0, 80, 160, 0.7);
    padding: 20px;
    display: none;
    overflow: auto;
}

#hud-close {
    position: absolute;
    top: 10px;
    right: 10px;
    width: 26px;
    height: 26px;
    border-radius: 50%;
    border: 1px solid rgba(120, 220, 255, 0.7);
    background: rgba(5, 25, 45, 0.9);
    color: #e5f6ff;
    cursor: pointer;
    font-size: 12px;
    box-shadow: 0 0 10px rgba(0, 200, 255, 0.7);
}

/* === ANIMAZIONI === */
@keyframes rotazione {
    from { transform: translate(-50%, -50%) rotate(0deg); }
    to   { transform: translate(-50%, -50%) rotate(360deg); }
}