body {
    margin: 0;
    font-family: 'Segoe UI', sans-serif;
    background-color: #f4f6f8;
    color: #333;
}

.centrado {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.contenedor {
    background: white;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 0 15px rgba(0,0,0,0.1);
    max-width: 500px;
    text-align: center;
}

h1 {
    color: #21a607;
}

.boton {
    display: inline-block;
    padding: 12px 20px;
    margin: 10px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: bold;
    color: white;
    transition: background-color 0.2s;
}

.boton:hover {
    opacity: 0.9;
}

.verde { background-color: #21a607; }
.azul  { background-color: #1976d2; }
.rojo  { background-color: #e53935; }
.gris  { background-color: #555; }

.alerta {
    background-color: #fff3cd;
    border: 1px solid #ffeeba;
    padding: 15px;
    border-radius: 8px;
    margin: 20px 0;
    color: #856404;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

th, td {
    padding: 12px;
    border: 1px solid #ccc;
    text-align: center;
}

th {
    background-color: #21a607;
    color: white;
}