main.css

*{
    box-sizing: border-box;
}

body{
    margin: 0;
    background: url(Sign\ in.jpg)rgba(0, 0, 0, .25);
	background-blend-mode: multiply;
	background-position: center;
	background-size: cover;
	background-repeat: no-repeat;
    font-family: 'Poppins';
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

h1{
    font-weight: bold;
    margin: 0;
}

.social ul li{
    list-style-type: none;
}

.social ul{
    display: flex;
    gap: 2em;
    padding: 0;
}

p {
	font-size: 14px;
	font-weight: 300;
	line-height: 20px;
	letter-spacing: 0.5px;
}

span {
	font-size: 12px;
}

a {
	color: #333;
	font-size: 14px;
	text-decoration: none;
	margin: 15px 0;
}

button {
	border-radius: 20px;
    border-color: #52c0e5;
	background: #4157ff;
	background: -webkit-linear-gradient(to right, #ff2bd1, #4157ff);
	background: linear-gradient(to right,#ff2bf1b4, #4157ff);
	color: #FFFFFF;
	font-size: 12px;
	font-weight: bold;
	padding: 12px 45px;
	letter-spacing: 1px;
	text-transform: uppercase;
	transition: transform 80ms ease-in;
}

button:active {
	transform: scale(0.95);
}


button.butt {
	background-color: transparent;
	border-color: #FFFFFF;
}

form {
	background-color: #FFFFFF;
	display: flex;
	align-items: center;
	justify-content: center;
	flex-direction: column;
	padding: 0 50px;
	height: 100%;
	text-align: center;
}

input {
	background-color: #eee;
	border: none;
	padding: 12px 15px;
	margin: 8px 0;
	width: 100%;
}

.container {
	background-color: #fff;
	border-radius: 10px;
  	box-shadow: 0 14px 28px rgba(0,0,0,0.25), 
			0 10px 10px rgba(0,0,0,0.22);
	position: relative;
	overflow: hidden;
	width: 768px;
	max-width: 100%;
	min-height: 480px;
}

.form-con {
	position: absolute;
	top: 0;
	height: 100%;
    transition: all 0.6s ease-in-out;
}

.signin_container {
	left: 0;
	width: 50%;
	z-index: 2;
}

.signup_container {
	left: 0;
	width: 50%;
	opacity: 0;
	z-index: 1;
	background-color: white;
}

.overlay-container {
	position: absolute;
	top: 0;
	left: 50%;
	width: 50%;
	height: 100%;
	overflow: hidden;
	z-index: 100;
    transition: transform 0.6s ease-in-out;
}

.overlay {
	background: #4157ff;
	background: -webkit-linear-gradient(to right, #ff2bd1d5, #4157ff);
	background: linear-gradient(to right, #ff2bf1d2, #4157ff );
	background-position: 0 0;
	color: #FFFFFF;
	position: relative;
	left: -100%;
	height: 100%;
	width: 200%;
  	transform: translateX(0);
	transition: transform 0.6s ease-in-out;
}

.panel {
	position: absolute;
	display: flex;
	align-items: center;
	justify-content: center;
	flex-direction: column;
	padding: 0 40px;
	text-align: center;
	top: 0;
	height: 100%;
	width: 50%;
	transform: translateX(0);
	transition: transform 0.6s ease-in-out;
}

.overlay-left {
	transform: translateX(-20%);
}

.overlay-right {
	right: 0;
	transform: translateX(0);
}



.container.right-panel-active .signin_container {
	transform: translateX(100%);
}

.container.right-panel-active .overlay-container{
	transform: translateX(-100%);
}

.container.right-panel-active .signup_container {
	transform: translateX(100%);
	opacity: 1;
	z-index: 5;
	animation: show 0.6s;
}

.container.right-panel-active .overlay {
    transform: translateX(50%);
}

.container.right-panel-active .overlay-left {
	transform: translateX(0);
}

.container.right-panel-active .overlay-right {
	transform: translateX(20%);
}

@media (max-width: 800px){
	.container{
		scale: .75;
	}
}

@media(max-height:700px){
	.container{
		min-height: 350px;
	}
	form{
		scale: .75;
		padding: 0px 20px;
	} 
	button,h1{
		scale: .75;
	}
	.overlay-left,.overlay-right{
		padding: 0px 20px;
	}
}

.container{
    animation: growin 3s cubic-bezier(0.075, 0.82, 0.165, 1)forwards;
    transform: scale(.4);
}

@keyframes growin {
    to{
        transform: scale(1);
    }
}