```css
/* =========================
   GENERAL
========================= */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, Helvetica, sans-serif;
}

html {
    scroll-behavior: smooth;
}

body {
    background: #f5f8fc;
    color: #222;
}


/* =========================
   HEADER
========================= */

header {
    background: linear-gradient(
        135deg,
        #3C78D8,
        #2456a6
    );

    color: white;

    padding: 22px 8%;

    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: bold;
}

nav {
    display: flex;
    gap: 25px;
}

nav a {
    color: white;
    text-decoration: none;
    font-weight: bold;
}

nav a:hover {
    text-decoration: underline;
}


/* =========================
   HERO
========================= */

.hero {
    min-height: 520px;

    display: flex;
    align-items: center;
    justify-content: space-between;

    gap: 50px;

    padding: 70px 8%;

    background: white;
}

.hero-text {
    max-width: 600px;
}

.hero-text h1 {
    font-size: 52px;
    line-height: 1.1;

    color: #2456a6;

    margin-bottom: 20px;
}

.hero-text h1 span {
    color: #3C78D8;
    display: block;
}

.hero-text p {
    font-size: 19px;
    line-height: 1.7;

    color: #555;

    margin-bottom: 30px;
}


/* =========================
   BOTONES
========================= */

.boton {
    display: inline-block;

    background: #3C78D8;

    color: white;

    text-decoration: none;

    padding: 15px 30px;

    border-radius: 30px;

    font-weight: bold;

    transition: 0.3s;
}

.boton:hover {
    background: #2456a6;
    transform: translateY(-3px);
}


/* =========================
   IMAGEN
========================= */

.hero-image {
    width: 45%;
    text-align: center;
}

.hero-image img {
    width: 100%;
    max-width: 500px;

    border-radius: 25px;

    box-shadow:
        0 15px 35px rgba(0, 0, 0, 0.15);
}


/* =========================
   SECCIONES
========================= */

.seccion {
    padding: 70px 8%;
    text-align: center;
}

.seccion h2 {
    font-size: 36px;

    color: #2456a6;

    margin-bottom: 15px;
}

.intro {
    color: #666;

    font-size: 18px;

    max-width: 700px;

    margin: auto;

    line-height: 1.6;
}


/* =========================
   TARJETAS
========================= */

.tarjetas {
    display: flex;

    justify-content: center;

    gap: 25px;

    margin-top: 45px;

    flex-wrap: wrap;
}

.tarjeta {
    background: white;

    width: 280px;

    padding: 30px;

    border-radius: 20px;

    box-shadow:
        0 8px 25px rgba(0, 0, 0, 0.08);

    transition: 0.3s;
}

.tarjeta:hover {
    transform: translateY(-6px);
}

.icono {
    font-size: 42px;

    margin-bottom: 15px;
}

.tarjeta h3 {
    color: #3C78D8;

    margin-bottom: 12px;
}

.tarjeta p {
    color: #666;

    line-height: 1.5;
}


/* =========================
   FORMULARIO
========================= */

/* =========================
   SECCIÓN DE CORREO
========================= */

.correo-unete {
    max-width: 650px;

    margin: 40px auto 0;

    padding: 40px 35px;

    background: white;

    border-radius: 22px;

    box-shadow:
        0 8px 25px rgba(0, 0, 0, 0.08);

    text-align: center;
}

.correo-icono {
    font-size: 45px;

    margin-bottom: 15px;
}

.correo-unete h3 {
    color: #3C78D8;

    font-size: 25px;

    margin-bottom: 15px;
}

.correo-unete p {
    color: #666;

    font-size: 17px;

    line-height: 1.6;
}

.correo-unete a {
    display: inline-block;

    margin: 18px 0;

    color: #2456a6;

    font-size: 20px;

    font-weight: bold;

    text-decoration: none;
}

.correo-unete a:hover {
    text-decoration: underline;
}

.correo-nota {
    font-size: 15px !important;

    color: #888 !important;

    margin-top: 5px;
}


    /* -------------------------
       VOLVER
    ------------------------- */

    .volver{

        padding:20px 0 50px;
    }


    .boton-volver{

        font-size:18px;

        padding:13px 30px;
    }


/* =========================
   FOOTER
========================= */

footer {
    background: #172d50;

    color: white;

    text-align: center;

    padding: 30px 8%;
}

footer p {
    margin: 6px 0;
}


/* =========================
   RESPONSIVE
========================= */

@media (max-width: 800px) {

    header {
        flex-direction: column;

        gap: 15px;

        text-align: center;
    }


    nav {
        gap: 15px;

        flex-wrap: wrap;

        justify-content: center;
    }


    .hero {
        flex-direction: column;

        text-align: center;

        padding: 50px 6%;
    }


    .hero-text h1 {
        font-size: 40px;
    }


    .hero-image {
        width: 100%;
    }


    .hero-image img {
        max-width: 450px;
    }


    .seccion {
        padding: 55px 6%;
    }

}