Password Generator

  <link href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.11.2/css/all.min.css" rel="stylesheet">
  <link href="https://fonts.googleapis.com/css?family=Montserrat&amp;display=swap" rel="stylesheet">
  
  <div class="container">
    <h2 class="title">Password Generator</h2>
    <div class="result">
      <div class="result__title field-title">Generated Password</div>
      <div class="result__info right">click to copy</div>
      <div class="result__info left">copied</div>
      <div class="result__viewbox" id="result">CLICK GENERATE</div>
      <button id="copy-btn" style="--x: 0; --y: 0"><i class="far fa-copy"></i></button>
    </div>
    <div class="length range__slider" data-min="4" data-max="32">
      <div class="length__title field-title" data-length='0'>length:</div>
      <input id="slider" type="range" min="4" max="32" value="16" />
    </div>
  
    <div class="settings">
      <span class="settings__title field-title">settings</span>
      <div class="setting">
        <input type="checkbox" id="uppercase" checked />
        <label for="uppercase">Include Uppercase</label>
      </div>
      <div class="setting">
        <input type="checkbox" id="lowercase" checked />
        <label for="lowercase">Include Lowercase</label>
      </div>
      <div class="setting">
        <input type="checkbox" id="number" checked />
        <label for="number">Include Numbers</label>
      </div>
      <div class="setting">
        <input type="checkbox" id="symbol" />
        <label for="symbol">Include Symbols</label>
      </div>
    </div>
  
    <button class="btn generate" id="generate">Generate Password</button>
  </div>

* {
	margin: 0;
	padding: 0;
	box-sizing: border-box;
  }
  
  body {
	width: 100%;
	height: 100vh;
	background-image: linear-gradient(to top, #209cff 100%, #68e0cf 200%);
	display: flex;
	justify-content: center;
	align-items: center;
  }
  
  button {
	border: 0;
	outline: 0;
  }
  
  .container {
	margin: 40px 0;
	width: 400px;
	height: 600px;
	padding: 10px 25px;
	background: #0a0e31;
	border-radius: 10px;
	box-shadow: 0 0 5px rgba(0, 0, 0, 0.45), 0 4px 8px rgba(0, 0, 0, 0.35), 0 8px 12px rgba(0, 0, 0, 0.15);
	font-family: "Montserrat";
  }
  .container h2.title {
	font-size: 1.75rem;
	margin: 10px -5px;
	margin-bottom: 30px;
	color: #fff;
  }
  
  .result {
	position: relative;
	width: 100%;
	height: 65px;
	overflow: hidden;
  }
  .result__info {
	position: absolute;
	bottom: 4px;
	color: #fff;
	font-size: 0.8rem;
	transition: all 150ms ease-in-out;
	transform: translateY(200%);
	opacity: 0;
  }
  .result__info.right {
	right: 8px;
  }
  .result__info.left {
	left: 8px;
  }
  .result__viewbox {
	width: 100%;
	height: 100%;
	background: rgba(255, 255, 255, 0.08);
	border-radius: 8px;
	color: #fff;
	text-align: center;
	line-height: 65px;
  }
  .result #copy-btn {
	position: absolute;
	top: var(--y);
	left: var(--x);
	width: 38px;
	height: 38px;
	background: #fff;
	border-radius: 50%;
	opacity: 0;
	transform: translate(-50%, -50%) scale(0);
	transition: all 350ms cubic-bezier(0.175, 0.885, 0.32, 1.275);
	cursor: pointer;
	z-index: 2;
  }
  .result #copy-btn:active {
	box-shadow: 0 0 0 200px rgba(255, 255, 255, 0.08);
  }
  .result:hover #copy-btn {
	opacity: 1;
	transform: translate(-50%, -50%) scale(1.35);
  }
  
  .field-title {
	position: absolute;
	top: -10px;
	left: 8px;
	transform: translateY(-50%);
	font-weight: 800;
	color: rgba(255, 255, 255, 0.5);
	text-transform: uppercase;
	font-size: 0.65rem;
	pointer-events: none;
	user-select: none;
  }
  
  .options {
	width: 100%;
	height: auto;
	margin: 50px 0;
  }
  
  .range__slider {
	position: relative;
	width: 100%;
	height: calc(65px - 10px);
	display: flex;
	justify-content: center;
	align-items: center;
	background: rgba(255, 255, 255, 0.08);
	border-radius: 8px;
	margin: 30px 0;
  }
  .range__slider::before, .range__slider::after {
	position: absolute;
	color: #fff;
	font-size: 0.9rem;
	font-weight: bold;
  }
  .range__slider::before {
	content: attr(data-min);
	left: 10px;
  }
  .range__slider::after {
	content: attr(data-max);
	right: 10px;
  }
  .range__slider .length__title::after {
	content: attr(data-length);
	position: absolute;
	right: -16px;
	font-variant-numeric: tabular-nums;
	color: #fff;
  }
  
  #slider {
	-webkit-appearance: none;
	width: calc(100% - (70px));
	height: 2px;
	border-radius: 5px;
	background: rgba(255, 255, 255, 0.314);
	outline: none;
	padding: 0;
	margin: 0;
	cursor: pointer;
  }
  #slider::-webkit-slider-thumb {
	-webkit-appearance: none;
	width: 20px;
	height: 20px;
	border-radius: 50%;
	background: white;
	cursor: pointer;
	transition: all 0.15s ease-in-out;
  }
  #slider::-webkit-slider-thumb:hover {
	background: #d4d4d4;
	transform: scale(1.2);
  }
  #slider::-moz-range-thumb {
	width: 20px;
	height: 20px;
	border: 0;
	border-radius: 50%;
	background: white;
	cursor: pointer;
	transition: background 0.15s ease-in-out;
  }
  #slider::-moz-range-thumb:hover {
	background: #d4d4d4;
  }
  
  .settings {
	position: relative;
	height: auto;
	widows: 100%;
	display: flex;
	flex-direction: column;
  }
  .settings .setting {
	position: relative;
	width: 100%;
	height: calc(65px - 10px);
	background: rgba(255, 255, 255, 0.08);
	border-radius: 8px;
	display: flex;
	align-items: center;
	padding: 10px 25px;
	color: #fff;
	margin-bottom: 8px;
  }
  .settings .setting input {
	opacity: 0;
	position: absolute;
  }
  .settings .setting input + label {
	user-select: none;
  }
  .settings .setting input + label::before, .settings .setting input + label::after {
	content: "";
	position: absolute;
	transition: 150ms cubic-bezier(0.24, 0, 0.5, 1);
	transform: translateY(-50%);
	top: 50%;
	right: 10px;
	cursor: pointer;
  }
  .settings .setting input + label::before {
	height: 30px;
	width: 50px;
	border-radius: 30px;
	background: rgba(214, 214, 214, 0.434);
  }
  .settings .setting input + label::after {
	height: 24px;
	width: 24px;
	border-radius: 60px;
	right: 32px;
	background: #fff;
  }
  .settings .setting input:checked + label:before {
	background: #5d68e2;
	transition: all 150ms cubic-bezier(0, 0, 0, 0.1);
  }
  .settings .setting input:checked + label:after {
	right: 14px;
  }
  .settings .setting input:focus + label:before {
	box-shadow: 0 0 0 2px rgba(255, 255, 255, 0.75);
  }
  .settings .setting input:disabled + label:before, .settings .setting input:disabled + label:after {
	cursor: not-allowed;
  }
  .settings .setting input:disabled + label:before {
	background: #4f4f6a;
  }
  .settings .setting input:disabled + label:after {
	background: #909090;
  }
  
  .btn.generate {
	user-select: none;
	position: relative;
	width: 100%;
	height: 50px;
	margin: 10px 0;
	border-radius: 8px;
	color: #fff;
	border: none;
	background-image: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
	letter-spacing: 1px;
	font-weight: bold;
	text-transform: uppercase;
	cursor: pointer;
	transition: all 150ms ease;
  }
  .btn.generate:active {
	transform: translateY(-3%);
	box-shadow: 0 4px 8px rgba(255, 255, 255, 0.08);
  }
  
  .support {
	position: fixed;
	right: 10px;
	bottom: 10px;
	padding: 10px;
	display: flex;
  }
  
  a {
	margin: 0 20px;
	color: #fff;
	font-size: 2rem;
	transition: all 400ms ease;
  }
  
  a:hover {
	color: #222;
  }
  
  .github-corner svg {
	position: absolute;
	right: 0;
	top: 0;
	mix-blend-mode: darken;
	color: #eeeeee;
	fill: #353535;
	clip-path: polygon(0 0, 100% 0, 100% 100%);
  }
  
  .github-corner:hover .octo-arm {
	animation: octocat-wave 0.56s;
  }
  
  @keyframes octocat-wave {
	0%, 100% {
	  transform: rotate(0);
	}
	20%, 60% {
	  transform: rotate(-20deg);
	}
	40%, 80% {
	  transform: rotate(10deg);
	}
  }

console.clear();

const sliderProps = {
	fill: "#0B1EDF",
	background: "rgba(255, 255, 255, 0.214)",
};

const slider = document.querySelector(".range__slider");

const sliderValue = document.querySelector(".length__title");

slider.querySelector("input").addEventListener("input", event => {
	sliderValue.setAttribute("data-length", event.target.value);
	applyFill(event.target);
});

applyFill(slider.querySelector("input"));

function applyFill(slider) {
	const percentage = (100 * (slider.value - slider.min)) / (slider.max - slider.min);
	const bg = `linear-gradient(90deg, ${sliderProps.fill} ${percentage}%, ${sliderProps.background} ${percentage +
			0.1}%)`;
	slider.style.background = bg;
	sliderValue.setAttribute("data-length", slider.value);
}

const randomFunc = {
	lower: getRandomLower,
	upper: getRandomUpper,
	number: getRandomNumber,
	symbol: getRandomSymbol,
};


function secureMathRandom() {
	return window.crypto.getRandomValues(new Uint32Array(1))[0] / (Math.pow(2, 32) - 1);
}

function getRandomLower() {
	return String.fromCharCode(Math.floor(Math.random() * 26) + 97);
}
function getRandomUpper() {
	return String.fromCharCode(Math.floor(Math.random() * 26) + 65);
}
function getRandomNumber() {
	return String.fromCharCode(Math.floor(secureMathRandom() * 10) + 48);
}
function getRandomSymbol() {
	const symbols = '~!@#$%^&*()_+{}":?><;.,';
	return symbols[Math.floor(Math.random() * symbols.length)];
}


const resultEl = document.getElementById("result");

const lengthEl = document.getElementById("slider");

const uppercaseEl = document.getElementById("uppercase");
const lowercaseEl = document.getElementById("lowercase");
const numberEl = document.getElementById("number");
const symbolEl = document.getElementById("symbol");

// Button to generate the password
const generateBtn = document.getElementById("generate");
// Button to copy the text
const copyBtn = document.getElementById("copy-btn");
// Result viewbox container
const resultContainer = document.querySelector(".result");
// Text info showed after generate button is clicked
const copyInfo = document.querySelector(".result__info.right");
// Text appear after copy button is clicked
const copiedInfo = document.querySelector(".result__info.left");

let generatedPassword = false;

let resultContainerBound = {
	left: resultContainer.getBoundingClientRect().left,
	top: resultContainer.getBoundingClientRect().top,
};

resultContainer.addEventListener("mousemove", e => {
	resultContainerBound = {
		left: resultContainer.getBoundingClientRect().left,
		top: resultContainer.getBoundingClientRect().top,
	};
	if(generatedPassword){
		copyBtn.style.opacity = '1';
		copyBtn.style.pointerEvents = 'all';
		copyBtn.style.setProperty("--x", `${e.x - resultContainerBound.left}px`);
		copyBtn.style.setProperty("--y", `${e.y - resultContainerBound.top}px`);
	}else{
		copyBtn.style.opacity = '0';
		copyBtn.style.pointerEvents = 'none';
	}
});
window.addEventListener("resize", e => {
	resultContainerBound = {
		left: resultContainer.getBoundingClientRect().left,
		top: resultContainer.getBoundingClientRect().top,
	};
});

// Copy Password in clipboard
copyBtn.addEventListener("click", () => {
	const textarea = document.createElement("textarea");
	const password = resultEl.innerText;
	if (!password || password == "CLICK GENERATE") {
		return;
	}
	textarea.value = password;
	document.body.appendChild(textarea);
	textarea.select();
	document.execCommand("copy");
	textarea.remove();

	copyInfo.style.transform = "translateY(200%)";
	copyInfo.style.opacity = "0";
	copiedInfo.style.transform = "translateY(0%)";
	copiedInfo.style.opacity = "0.75";
});

// When Generate is clicked Password id generated.
generateBtn.addEventListener("click", () => {
	const length = +lengthEl.value;
	const hasLower = lowercaseEl.checked;
	const hasUpper = uppercaseEl.checked;
	const hasNumber = numberEl.checked;
	const hasSymbol = symbolEl.checked;
	generatedPassword = true;
	resultEl.innerText = generatePassword(length, hasLower, hasUpper, hasNumber, hasSymbol);
	copyInfo.style.transform = "translateY(0%)";
	copyInfo.style.opacity = "0.75";
	copiedInfo.style.transform = "translateY(200%)";
	copiedInfo.style.opacity = "0";
});

// Function responsible to generate password and then returning it.
function generatePassword(length, lower, upper, number, symbol) {
	let generatedPassword = "";
	const typesCount = lower + upper + number + symbol;
	const typesArr = [{ lower }, { upper }, { number }, { symbol }].filter(item => Object.values(item)[0]);
	if (typesCount === 0) {
		return "";
	}
	for (let i = 0; i < length; i++) {
		typesArr.forEach(type => {
			const funcName = Object.keys(type)[0];
			generatedPassword += randomFunc[funcName]();
		});
	}
	return generatedPassword.slice(0, length)
									.split('').sort(() => Math.random() - 0.5)
									.join('');
}

function disableOnlyCheckbox(){
	let totalChecked = [uppercaseEl, lowercaseEl, numberEl, symbolEl].filter(el => el.checked)
	totalChecked.forEach(el => {
		if(totalChecked.length == 1){
			el.disabled = true;
		}else{
			el.disabled = false;
		}
	})
}

[uppercaseEl, lowercaseEl, numberEl, symbolEl].forEach(el => {
	el.addEventListener('click', () => {
		disableOnlyCheckbox()
	})
})