:root {
    --rojo: #d32f2f;
    --azul: #1e3a8a;
    --verde: #2e7d32;
    --blanco: #ffffff;
    --gris-fondo: #f3f4f6;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Arial, sans-serif;
    background-color: var(--gris-fondo);
}

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

header {
    display: flex;
    align-items: center;
    gap: 20px;
    background: linear-gradient(90deg, var(--rojo), var(--azul));
    color: var(--blanco);
    padding: 15px 30px;
    border-bottom: 6px solid var(--verde);
}

header img {
    height: 70px;
    background-color: var(--blanco);
    padding: 6px;
    border-radius: 8px;
}

header h1 {
    margin: 0;
    font-size: 26px;
}

/* ================= MAIN ================= */

main {
    padding: 30px;
}

.grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 30px;
}

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

.card {
    background-color: var(--blanco);
    border-radius: 10px;
    overflow: hidden;
    text-decoration: none;
    color: var(--azul);
    box-shadow: 0 3px 6px rgba(0,0,0,0.15);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    border-left: 6px solid var(--rojo);
    display: flex;
    flex-direction: column;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 12px rgba(0,0,0,0.25);
    border-left-color: var(--verde);
}

/* ===== CONTENEDOR DE IMAGEN ===== */

.card-img {
    height: 160px;
    background-color: #f9f9f9;
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.card-img img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    display: block;
}

/* ===== TEXTO ===== */

.card p {
    margin: 0;
    padding: 12px;
    text-align: center;
    font-size: 14px;
    font-weight: bold;
    background-color: var(--blanco);
}

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

footer {
    background: linear-gradient(90deg, var(--azul), var(--rojo));
    color: var(--blanco);
    text-align: center;
    padding: 15px;
    border-top: 6px solid var(--verde);
    margin-top: 40px;
    font-size: 14px;
}

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

@media (max-width: 900px) {
    .grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    .grid {
        grid-template-columns: 1fr;
    }

    header {
        flex-direction: column;
        text-align: center;
    }
}

.logo-link {
    display: flex;
    align-items: center;
    gap: 20px;
    text-decoration: none;
    color: white;
}

.logo-link:hover {
    text-decoration: underline;
}