body{
    background-image: url(img/jinx8.jpg);
    background-attachment: fixed;
    background-position: center center;
    background-size: cover;
}
:root {
    --fondo-base: #ffffff36;
    --fondo-hover: #8080809c;
    --borde: black;
    --borde-hover: white;
    --sombra: 0 2px 4px black;
    --sombra-hover: 0 2px 4px white;
    --ancho: 1300px;
}

body {
    background-color: #f0f0f0;
    font-family: sans-serif;
    animation: fondoAnimado 10s infinite alternate;
}

@keyframes fondoAnimado {
    0% { background-color: #f0f0f0; }
    100% { background-color: #dcdcdc; }
}

#landing-header {
    width: var(--ancho);
    margin: auto;
    margin-top: 20px;
    height: 100px;
    background-color: var(--fondo-base);
    border: 1px outset var(--borde);
    box-shadow: var(--sombra);
    text-align: center;
    line-height: 100px;
    font-size: 28px;
    animation: entradaDeslizar 1s ease-out forwards;
    transform: translateY(-50px);
    opacity: 0;
}

@keyframes entradaDeslizar {
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

#landing-contenido {
    width: var(--ancho);
    margin: auto;
    margin-top: 30px;
    overflow: hidden;
}

.landing-card {
    float: left;
    width: 400px;
    height: 200px;
    margin: 15px;
    background-color: var(--fondo-base);
    border: 1px outset var(--borde);
    box-shadow: var(--sombra);
    text-align: center;
    line-height: 200px;
    font-weight: bold;
    transition: all 0.3s ease;
    animation: aparecer 1s ease forwards;
    opacity: 0;
}

.landing-card:nth-child(1) { animation-delay: 0.5s; }
.landing-card:nth-child(2) { animation-delay: 0.8s; }
.landing-card:nth-child(3) { animation-delay: 1.1s; }
.landing-card:nth-child(4) { animation-delay: 1.5s; }
.landing-card:nth-child(5) { animation-delay: 1.8s; }
.landing-card:nth-child(6) { animation-delay: 2.1s; }
.landing-card:nth-child(7) { animation-delay: 2.5s; }
.landing-card:nth-child(8) { animation-delay: 2.8s; }
.landing-card:nth-child(9) { animation-delay: 3.1s; }
.landing-card:nth-child(10) { animation-delay: 3.5s; }
.landing-card:nth-child(11) { animation-delay: 3.8s; }
.landing-card:nth-child(12) { animation-delay: 4.1s; }

@keyframes aparecer {
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.landing-card:hover {
    background-color: var(--fondo-hover);
    box-shadow: var(--sombra-hover);
    border: 1px outset var(--borde-hover);
    transform: scale(1.05) rotate(1deg);
}

#landing-footer {
    width: var(--ancho);
    margin: auto;
    margin-top: 30px;
    height: 80px;
    background-color: var(--fondo-base);
    border: 1px outset var(--borde);
    box-shadow: var(--sombra);
    text-align: center;
    line-height: 80px;
    font-size: 16px;
}