body {
        font-family: 'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode';
        margin: 30px;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        min-height: calc(100vh - 60px);
    }

    h2 {
        margin-bottom: 2px;
        font-size: 24px;
        color: blue;
        text-decoration: underline;
        text-align: center;
    }

    form {
        background-color: #f5f5f5;
        padding: 20px;
        border-radius: 8px;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
        max-width: 400px;
        margin: 20px auto 0 auto;
        width: 100%;
    }

    #mensaje_notas {
        margin-top: 20px;
        background-color: #f5f5f5;
        padding: 10px;
        border-radius: 8px;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
        max-width: 400px;
        color: #666;
        font-size: 0.9em;
        margin-bottom: 15px;
    }

    label {
        font-size: 1.1em;
        font-weight: bold;
        color: #333;
        display: block;
        margin-bottom: 5px;
    }

    input[type="text"] {
        font-size: 1.1em;
        padding: 10px;
        border: 2px solid #ddd;
        border-radius: 4px;
        width: 100%;
        box-sizing: border-box;
        margin-bottom: 15px;
        transition: border-color 0.3s;
    }

    input[type="text"]:focus {
        outline: none;
        border-color: #4CAF50;
        box-shadow: 0 0 5px rgba(76, 175, 80, 0.3);
    }

    button {
        background-color: #4CAF50;
        color: white;
        font-size: 1.1em;
        font-weight: bold;
        padding: 12px 24px;
        border: none;
        border-radius: 4px;
        cursor: pointer;
        transition: background-color 0.3s, transform 0.1s;
        width: 100%;
    }

    button:hover {
        background-color: #45a049;
        transform: translateY(-2px);
    }

    button:active {
        transform: translateY(0);
    }
    
    #resultado {
        margin: 20px auto 0 auto;
        padding: 20px;
        border-radius: 8px;
        font-weight: bold;
        font-size: 1.2em;
        text-align: center;
        min-height: 20px;
        max-width: 400px;
        width: 100%;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
        box-sizing: border-box;
    }

    #resultado:not(:empty) {
        background-color: #e8f5e8;
        border: 2px solid #4CAF50;
        color: #2e7d32;
    }
    
    .error {
        background-color: #ffebee !important;
        border: 2px solid #f44336 !important;
        color: #d32f2f !important;
    }