* {
    box-sizing: border-box;
}

body {
    font-family: system-ui, -apple-system, sans-serif;
    margin: 0;
    padding: 0;
    overflow: hidden;
}

:root {
    --tank-size: 100px;
    --tank-bottom: 100px;
    --hero-height: 600px;
    /* Anchos calculados para loops perfectos (AnchoNatural / AltoNatural * AltoRenderizado) */
    --w1: 2171px;
    --w2: 2198px;
    --w3: 2102px;
    --w4: 2605px;
    --w5: 2607px;
    --w6: 1564px;
}

@media (max-width: 700px) {
    :root {
        --tank-size: 50px;
        --tank-bottom: 60px;
        --hero-height: 400px;
        /* Anchos móviles (AnchoNatural / AltoNatural * AltoMóvil) */
        --w1: 1277px;
        --w2: 1318px;
        --w3: 1236px;
        --w4: 1488px;
        --w5: 1564px;
        --w6: 938px;
    }
}

.hero {
    width: 100%;
    min-height: var(--hero-height);
    position: relative;
    top: 0;
    left: 0;
    background: linear-gradient(to bottom, #e3f2fd 600px, #ffffff 600px);
    overflow: hidden;
}

/* Base style for all parallax elements */
.parallax-layer {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-repeat: repeat-x;
    background-position: 0 100%;
}

.bike-1,
.bike-2,
.bike-3,
.bike-4 {
    z-index: 9;
    position: absolute;
    bottom: var(--tank-bottom);
    left: 0;
    width: 100%;
    height: 100%;
    background-size: auto var(--tank-size);
    background-position: 0 100%;
    background-repeat: no-repeat;
    transition: all 0.3s ease;
}

.bike-1 {
    background-image: url('../2.1.4_Recursos/2.1.4.1_Paralax/amx_vci.png');
    background-size: auto calc(var(--tank-size) * 1.10);
}

.bike-2 {
    background-image: url('../2.1.4_Recursos/2.1.4.1_Paralax/tanqueSD.png');
}

.bike-3 {
    background-image: url('../2.1.4_Recursos/2.1.4.1_Paralax/amx_155.png');
}

.bike-4 {
    background-image: url('../2.1.4_Recursos/2.1.4.1_Paralax/howo.png');
    background-size: auto calc(var(--tank-size) * 1.20);
}


.bike-1 {
    animation: parallax_bike linear 40s infinite both 10s;
}

.bike-2 {
    animation: parallax_bike linear 40s infinite both 0s;
}

.bike-3 {
    animation: parallax_bike linear 40s infinite both 20s;
}

.bike-4 {
    animation: parallax_bike linear 40s infinite both 30s;
}




.layer-1 {
    animation: loop_l1 linear 20s infinite;
    background-image: url('../2.1.4_Recursos/2.1.4.1_Paralax/2.png');
    z-index: 10;
    background-size: auto 136px;
}

.layer-2 {
    animation: loop_l2 linear 30s infinite;
    background-image: url('../2.1.4_Recursos/2.1.4.1_Paralax/3.png');
    z-index: 9;
    background-size: auto 150px;
}

.layer-3 {
    animation: loop_l3 linear 55s infinite;
    background-image: url('../2.1.4_Recursos/2.1.4.1_Paralax/4.png');
    z-index: 8;
    background-size: auto 425px;
}

.layer-4 {
    animation: loop_l4 linear 75s infinite;
    background-image: url('../2.1.4_Recursos/2.1.4.1_Paralax/5.png');
    z-index: 7;
    background-size: auto 350px;
}

.layer-5 {
    animation: loop_l5 linear 95s infinite;
    background-image: url('../2.1.4_Recursos/2.1.4.1_Paralax/6.png');
    z-index: 6;
    background-size: auto 250px;
}

.layer-6 {
    animation: loop_l6 linear 120s infinite;
    background-image: url('../2.1.4_Recursos/2.1.4.1_Paralax/6.png');
    z-index: 5;
    background-size: auto 150px;
}

@media (max-width: 700px) {
    .hero {
        background: linear-gradient(to bottom, #e3f2fd 400px, #ffffff 400px);
        min-height: 400px;
    }

    .layer-1 {
        background-size: auto 80px;
    }

    .layer-2 {
        background-size: auto 90px;
    }

    .layer-3 {
        background-size: auto 250px;
    }

    .layer-4 {
        background-size: auto 200px;
    }

    .layer-5 {
        background-size: auto 150px;
    }

    .layer-6 {
        background-size: auto 90px;
    }
}


@keyframes loop_l1 {
    from {
        background-position: var(--w1) 100%;
    }

    to {
        background-position: 0 100%;
    }
}

@keyframes loop_l2 {
    from {
        background-position: var(--w2) 100%;
    }

    to {
        background-position: 0 100%;
    }
}

@keyframes loop_l3 {
    from {
        background-position: var(--w3) 100%;
    }

    to {
        background-position: 0 100%;
    }
}

@keyframes loop_l4 {
    from {
        background-position: var(--w4) 100%;
    }

    to {
        background-position: 0 100%;
    }
}

@keyframes loop_l5 {
    from {
        background-position: var(--w5) 100%;
    }

    to {
        background-position: 0 100%;
    }
}

@keyframes loop_l6 {
    from {
        background-position: var(--w6) 100%;
    }

    to {
        background-position: 0 100%;
    }
}

@keyframes parallax_bike {
    0% {
        background-position: -300px 100%;
    }

    100% {
        background-position: 2000px 100%;
    }
}

.logo {
    position: absolute;
    top: 20px;
    z-index: 4;
    width: 100%;
    pointer-events: none;
}

.logo h1 {
    font-family: system-ui, -apple-system, sans-serif;
    font-weight: 900;
    font-size: 5rem;
    text-align: center;
    color: #fff;
    text-transform: uppercase;
    margin: 0;
    letter-spacing: 5px;
    text-shadow: 2px 2px 10px rgba(0, 0, 0, 0.5);
}

@media (max-width: 700px) {
    .logo h1 {
        font-size: 2.5rem;
        letter-spacing: 2px;
    }
}

/* Animated Birds */
.bird {
    position: absolute;
    top: 0;
    left: -100px;
    width: 18px;
    height: 2px;
    z-index: 0;
    opacity: 0.7;
}

.bird-body {
    position: relative;
    width: 100%;
    height: 100%;
}

.bird-wing {
    position: absolute;
    top: 0;
    width: 55%;
    height: 1.5px;
    background: #1a1a1a;
    border-radius: 1px;
}

.wing-left {
    left: 0;
    transform-origin: right center;
    animation: flap-left 0.3s infinite alternate ease-in-out;
}

.wing-right {
    right: 0;
    transform-origin: left center;
    animation: flap-right 0.3s infinite alternate ease-in-out;
}

@keyframes flap-left {
    from {
        transform: rotate(35deg);
    }

    to {
        transform: rotate(-35deg);
    }
}

@keyframes flap-right {
    from {
        transform: rotate(-35deg);
    }

    to {
        transform: rotate(35deg);
    }
}

@keyframes fly-across {
    from {
        transform: translate(-100px, 0) scale(1.2);
    }

    to {
        transform: translate(2200px, -80px) scale(0.8);
    }
}

.animate-fly {
    animation: fly-across linear infinite;
}

/* Clouds (Extra for a better sky) */
.cloud {
    position: absolute;
    width: 220px;
    height: 70px;
    background: #fff;
    border-radius: 200px;
    opacity: 0.5;
    filter: blur(18px);
    z-index: 0;
}

.cloud::before,
.cloud::after {
    content: '';
    position: absolute;
    background: #fff;
    width: 110px;
    height: 110px;
    top: -55px;
    left: 15px;
    border-radius: 100%;
}

.cloud::after {
    width: 130px;
    height: 130px;
    top: -75px;
    left: 75px;
}

.animate-cloud-slow {
    animation: moveClouds linear infinite;
}

@keyframes moveClouds {
    from {
        transform: translateX(-350px);
    }

    to {
        transform: translateX(2200px);
    }
}