body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    text-align: center;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    padding: 20px;
    min-height: 100vh;
    margin: 0;
}

#registro {
    background: #ffffff;
    padding: 25px;
    width: 90%;
    max-width: 500px;
    margin: 30px auto;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    border-radius: 15px;
    border-top: 5px solid #fc4a4a;
    border-bottom: 5px solid #fc4a4a;
}

input {
    width: 85%;
    padding: 12px;
    margin: 15px 0;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 16px;
    transition: all 0.3s;
}

input:focus {
    border-color: #fc4a4a;
    outline: none;
    box-shadow: 0 0 0 3px rgba(252, 74, 74, 0.2);
}

button {
    padding: 12px 25px;
    margin: 15px 10px;
    cursor: pointer;
    border: none;
    background-color: #007bff;
    color: white;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    transition: all 0.3s;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

button:enabled {
    background-color: #28a745;
    color: white;
}

button:disabled {
    background-color: #cccccc;
    color: #666666;
    cursor: not-allowed;
    box-shadow: none;
    transform: none;
}

#verificar {
    background-color: #007bff;
}

#verificar:enabled:hover {
    background-color: #0056b3;
    transform: translateY(-2px);
    box-shadow: 0 6px 8px rgba(0, 0, 0, 0.15);
}

#nuevoEjercicio {
    background-color: #ffc107;
    color: #212529;
}

#nuevoEjercicio:enabled:hover {
    background-color: #e0a800;
    transform: translateY(-2px);
    box-shadow: 0 6px 8px rgba(0, 0, 0, 0.15);
}

#mensajeBienvenida {
    font-size: 2.2rem;
    font-weight: bold;
    color: #eb7c48;
    text-align: center;
    margin: 20px 0;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
    
}

#puntaje {
    font-size: 1.5rem;
    font-weight: bold;
    color: #ffffff;
    text-align: center;
    margin: 15px auto;
    background: linear-gradient(135deg, #c12e2e 0%, #eb7c48 100%);
    padding: 12px 25px;
    border-radius: 30px;
    display: inline-block;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    border: 2px solid white;
}

#ejercicios {
    display: none;
    background: #ffffff;
    padding: 30px;
    width: 95%;
    max-width: 900px;
    margin: 30px auto;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
    border-radius: 15px;
    border-top: 5px solid #28a745;
    border-bottom: 5px solid #28a745;
}

table {
    margin: 20px auto;
    border-collapse: separate;
    border-spacing: 0;
    width: 95%;
    max-width: 850px;
    background: #ffffff;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    border-radius: 10px;
    overflow: hidden;
}

th {
    background: linear-gradient(135deg, #04362a 0%, #0a6e5a 100%);
    color: white;
    padding: 16px;
    font-size: 1.1rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

td {
    border: 1px solid #e0e0e0;
    padding: 16px;
    text-align: center;
    font-size: 1rem;
    transition: background-color 0.3s;
}



select {
    padding: 10px 15px;
    border-radius: 8px;
    border: 2px solid #007bff;
    font-size: 1rem;
    width: 120px;
    cursor: pointer;
    transition: all 0.3s;
}

select:focus {
    border-color: #0056b3;
    outline: none;
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.25);
}

.correct {
    background-color: #e8f5e9;
    border-left: 4px solid #2e7d32;
}

.incorrect {
    background-color: #ffebee;
    border-left: 4px solid #c62828;
}

#resultado {
    font-size: 1.2rem;
    font-weight: 600;
    margin: 20px 0;
    padding: 15px;
    border-radius: 8px;
    width: 90%;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

#instruccion {
    font-size: 1.1rem;
    color: #555;
    margin-bottom: 25px;
    font-style: italic;
}

@media (max-width: 768px) {
    #ejercicios {
        width: 98%;
        padding: 15px;
    }
    
    table {
        width: 100%;
    }
    
    th, td {
        padding: 12px 8px;
        font-size: 0.9rem;
    }
    
    select {
        width: 100%;
    }
    
    #mensajeBienvenida {
        font-size: 1.8rem;
    }
}