*{
    box-sizing:border-box;
}


body{

    margin:0;

    font-family:Segoe UI, Arial, Helvetica, sans-serif;

    background:#f5f5f5;

    color:#333;

}



/* =========================
   CABECERA GENERAL
========================= */


header{

    background:linear-gradient(135deg,#005A9C,#0078D7);

    color:white;

    padding:45px;

    text-align:center;

}


header h1{

    margin:0;

    font-size:38px;

}


header p{

    margin-top:12px;

    font-size:18px;

    opacity:.95;

}





/* =========================
   PORTADA - LISTADO CLASES
========================= */


.container{

    width:90%;

    max-width:1200px;

    margin:40px auto;

    display:grid;

    grid-template-columns:repeat(auto-fit,minmax(340px,1fr));

    gap:25px;

}



.card{

    background:white;

    border-radius:12px;

    padding:25px;

    box-shadow:0 3px 10px rgba(0,0,0,.15);

    transition:.25s;

}



.active:hover{

    transform:translateY(-4px);

    box-shadow:0 8px 20px rgba(0,0,0,.20);

}



.disabled{

    opacity:.65;

}



.card h2{

    color:#005A9C;

    margin-top:8px;

}



.card p{

    line-height:1.7em;

}





/* =========================
   CONTENIDO DE LAS CLASES
========================= */


.lesson{

    width:90%;

    max-width:1000px;

    margin:40px auto;

    background:white;

    border-radius:12px;

    padding:40px;

    box-shadow:0 3px 10px rgba(0,0,0,.15);

}



.lesson h2{

    color:#005A9C;

    margin-top:40px;

    border-bottom:2px solid #005A9C;

    padding-bottom:8px;

}



.lesson h3{

    color:#0078D7;

    margin-top:30px;

}



.lesson p{

    line-height:1.7em;

}



.lesson li{

    margin-bottom:8px;

}



hr{

    border:0;

    border-top:1px solid #ddd;

    margin:35px 0;

}





/* =========================
   BADGES
========================= */


.badge{

    display:inline-block;

    background:#28a745;

    color:white;

    padding:6px 12px;

    border-radius:20px;

    font-size:13px;

    font-weight:bold;

}



.gray{

    background:#8b8b8b;

}





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


.button{

    display:inline-block;

    margin-top:20px;

    background:#005A9C;

    color:white;

    text-decoration:none;

    padding:12px 22px;

    border-radius:6px;

    font-weight:bold;

    transition:.2s;

}



.button:hover{

    background:#00447a;

}





/* =========================
   TABLAS
========================= */


table{

    width:100%;

    border-collapse:collapse;

    margin:25px 0;

}



th{

    background:#005A9C;

    color:white;

    padding:12px;

    text-align:left;

}



td{

    padding:12px;

    border-bottom:1px solid #ddd;

}



tr:hover{

    background:#f5f5f5;

}





/* =========================
   IMAGENES
========================= */


.imagen{

    max-width:100%;

    display:block;

    margin:25px auto;

}





/* =========================
   COMANDOS CISCO
========================= */


pre{

    background:#222;

    color:white;

    padding:15px;

    border-radius:8px;

    overflow-x:auto;

    font-family:Consolas,monospace;

}





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


footer{

    margin-top:50px;

    text-align:center;

    color:#666;

    padding:30px;

    border-top:1px solid #ddd;

}