document.getElementById('password').oninput = function () {
    var password = this.value;
    var strengthText = document.getElementById('password-strength');
    var strength = getPasswordStrength(password);

    strengthText.innerHTML = strength.text.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
    strengthText.className = strength.class;
};

function getPasswordStrength(password) {
    var strength = { text: '', class: '' };

    if (password.length < 6) {
        strength.text = 'Weak';
        strength.class = 'password-weak';
    } else if (password.length < 10) {
        strength.text = 'Medium';
        strength.class = 'password-medium';
    } else {
        var hasUpperCase = /[A-Z]/.test(password);
        var hasLowerCase = /[a-z]/.test(password);
        var hasNumbers = /\d/.test(password);
        var hasSpecialChars = /[!@#$%^&*(),.?":{}|<>]/.test(password);

        if (hasUpperCase && hasLowerCase && hasNumbers && hasSpecialChars) {
            strength.text = 'Strong';
            strength.class = 'password-strong';
        } else {
            strength.text = 'Medium';
            strength.class = 'password-medium';
        }
    }

    return strength;
}