/* Solo lo del ANDAMIO de la demo. La interfaz de arriba no se toca: es la
   misma hoja que corre en el juego. */
body.demo {
    margin: 0;
    min-height: 100vh;
    font-family: system-ui, sans-serif;
    background: #05070a;
    overflow: hidden;
}

/* En el juego detrás hay partida. Sobre negro, una NUI no se juzga bien:
   se ve el contraste real solo cuando hay algo debajo. */
.demo-fondo {
    position: fixed;
    inset: 0;
    background:
        radial-gradient(ellipse at 30% 20%, rgba(127, 212, 240, .10), transparent 60%),
        radial-gradient(ellipse at 75% 75%, rgba(43, 127, 163, .14), transparent 55%),
        linear-gradient(160deg, #0a1018, #05070a 60%);
}
.demo-fondo::after {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255, 255, 255, .022) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, .022) 1px, transparent 1px);
    background-size: 54px 54px;
    mask-image: radial-gradient(ellipse at 50% 40%, #000 30%, transparent 78%);
    -webkit-mask-image: radial-gradient(ellipse at 50% 40%, #000 30%, transparent 78%);
}

.demo-mando {
    position: fixed;
    top: 28px;
    left: 28px;
    width: 292px;
    z-index: 100;
    background: rgba(13, 17, 23, .93);
    border: 1px solid rgba(255, 255, 255, .10);
    border-radius: 14px;
    padding: 16px;
}
.demo-titulo {
    color: #7fd4f0;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: .16em;
    text-transform: uppercase;
    margin-bottom: 12px;
}
.demo-btn {
    display: block;
    width: 100%;
    text-align: left;
    background: rgba(255, 255, 255, .035);
    border: 1px solid rgba(255, 255, 255, .08);
    border-radius: 10px;
    padding: 10px 13px;
    margin-bottom: 8px;
    cursor: pointer;
    font: inherit;
    transition: background .18s, border-color .18s;
}
.demo-btn:hover {
    background: rgba(127, 212, 240, .09);
    border-color: rgba(127, 212, 240, .30);
}
.demo-btn b {
    display: block;
    color: rgba(255, 255, 255, .92);
    font-size: 13.5px;
    font-weight: 600;
    margin-bottom: 3px;
}
.demo-btn span {
    display: block;
    color: rgba(255, 255, 255, .48);
    font-size: 11.5px;
    line-height: 1.45;
}
.demo-volver {
    display: block;
    margin-top: 12px;
    color: rgba(255, 255, 255, .40);
    font-size: 12.5px;
    text-decoration: none;
}
.demo-volver:hover { color: #7fd4f0; }

@media (max-width: 780px) {
    .demo-mando { position: static; width: auto; margin: 16px; }
    body.demo { overflow: auto; }
}