* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    background: #f2f4f7;
    color: #333;
}

.contenedor {
    width: 90%;
    max-width: 1000px;
    margin: 40px auto;
    text-align: center;
}

h1 {
    margin-bottom: 10px;
    color: #1f3c88;
}

.subtitulo {
    color: #666;
    margin-bottom: 30px;
}

/* GRUPOS */

.grupos {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 20px;
    max-width: 1000px;
    margin: 40px auto;
}

.grupos a {
    text-decoration: none;
    background: #1f3c88;
    color: white;
    padding: 25px 10px;
    border-radius: 10px;
    text-align: center;
    transition: 0.3s;
}

.grupos a:hover {
    transform: translateY(-5px);
    opacity: 0.85;
}

.grupos strong {
    display: block;
    font-size: 28px;
    margin-bottom: 8px;
}

.grupos span {
    font-size: 14px;
}

@media (max-width: 700px) {
    .grupos {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* PÁGINA DEL HORARIO */

.horario h2 {
    font-size: 30px;
    color: #1f3c88;
    margin-bottom: 20px;
}

/* BOTONES */

.botones {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 25px;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 12px 20px;
    border-radius: 8px;
    text-decoration: none;
    color: white;
    font-weight: bold;
    transition: 0.3s;
}

.ver {
    background: #1f3c88;
}

.descargar {
    background: #198754;
}

.btn:hover {
    opacity: 0.85;
    transform: translateY(-2px);
}

/* VISOR DEL PDF */

.visor {
    width: 100%;
    height: 700px;
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0,0,0,0.15);
}

.visor iframe {
    width: 100%;
    height: 100%;
    border: none;
}

/* REGRESAR */

.regresar {
    display: inline-block;
    margin-top: 25px;
    text-decoration: none;
    color: #1f3c88;
    font-weight: bold;
}

/* RESPONSIVE */

@media (max-width: 800px) {

    .grupos {
        grid-template-columns: repeat(2, 1fr);
    }

    .visor {
        height: 600px;
    }
}

@media (max-width: 500px) {

    .grupos {
        grid-template-columns: 1fr;
    }

    .visor {
        height: 500px;
    }
}