body {
    font-family: Arial, sans-serif;
    background: #f5f7fa;
    margin: 0;
    padding: 20px;
}

.mensaje-exito {
    background: #d4edda;
    color: #155724;
    text-align: center;
    padding: 12px;
    margin-bottom: 20px;
    border-radius: 8px;
    font-weight: bold;
    border: 1px solid #c3e6cb;
}

.form-registro {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    background: #fff;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    max-width: 1000px;
    margin: auto;
}

.columna {
    flex: 1;
    min-width: 300px;
}

h3 {
    margin-bottom: 15px;
    color: #333;
    border-bottom: 2px solid #007BFF;
    padding-bottom: 5px;
}

.campo {
    display: flex;
    align-items: center;
    margin-bottom: 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 8px;
    background: #fafafa;
}

.campo i {
    color: #007BFF;
    margin-right: 10px;
    font-size: 18px;
}

.campo input {
    border: none;
    outline: none;
    flex: 1;
    background: transparent;
    font-size: 15px;
}

.boton {
    width: 100%;
    text-align: center;
    margin-top: 20px;
}

button {
    background: #007BFF;
    color: white;
    border: none;
    padding: 12px 20px;
    font-size: 16px;
    border-radius: 8px;
    cursor: pointer;
    transition: 0.3s;
}

button:hover {
    background: #0056b3;
}

/* 📱 RESPONSIVE */
@media (max-width: 768px) {
    .form-registro {
        flex-direction: column;
        padding: 15px;
    }

    .columna {
        min-width: 100%;
    }

    .campo {
        flex-direction: column;
        align-items: flex-start;
    }

    .campo i {
        margin-bottom: 8px;
    }

    button {
        width: 100%;
    }
}