style.css

@import url();
*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins',sans-serif;
}
body{
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: url(2.webp) no-repeat;
    background-size: 900px;
    background-position: center;

}
header{
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 10px 1px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 99;
}
.logo{
    font-size: 2em;
    color: rgb(5, 5, 5);
    user-select: none;
}
.navigation a {
    position: relative;
    font-size: 1.1em;
    color: rgb(3, 39, 71);
    text-decoration: none;
    font-weight: 500;
    margin-left: 40px;
}
.navigation a::after{
    content: '';
    position: absolute;
    left: 0;
    bottom: -6px;
    width: 100%;
    height: 3px;
    background: rgb(18, 16, 16);
    border-radius: 5px;
    transform-origin: right;
    transform: scaleX(0);
    transition: transform .5s;
}
.navigation a:hover::after{
    transform-origin: left;
    transform: scaleX(1);
}

.navigation .btn {
    width: 130px;
    height: 50px;
    background: transparent;
    border: 2px solid rgb(29, 19, 19);
    outline: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1.1em;
    color: rgb(90, 102, 114);
    font-weight: 500;
    margin-left: 40px;
    transition: .5s;
}
.navigation .btn:hover{
    background: rgb(30, 28, 28);
    color: rgb(244, 235, 235);
}

.wrapper{
    position: relative;
    width: 400px;
    height: 440px;
    background: transparent;
    border: 2px solid rgb(244, 235, 235);
    border-radius: 20px;
    backdrop-filter: blur(20px);
    box-shadow: 0 0 30px rgb(0, 0, 0, .5);
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    transform: scale(0);
    transition: transform .5s ease, height .2s ease;
}
.wrapper.active-popup{
    transform: scale(1);
}

.wrapper.active{
    height: 520px ;
}
.wrapper .form-box{
    width: 100%;
    padding: 40px;
}
.wrapper .form-box.login{
    transition: transform .18s ease;
    transform: translateX(0);
}

.wrapper.active .form-box.login{
    transition: none;
    transform: translateX(-400px);
}
 
.wrapper .form-box.register{
    position: absolute;
    transition: none;
    transform: translateX(400px);
}
.wrapper.active .form-box.register{
    transition: transform .18s ease;
    transform: translateX(0);
}

.wrapper .icon-close{
    position: absolute;
    top: 0;
    right: 0;
 width: 45px;
    background-color:white;
    font-size: 2em;
    color:black;
    display: flex;
    justify-content: center;
    align-items: center;
   border-bottom-left-radius: 20px;
    cursor: pointer;
    z-index: 1;
}
.form-box h2{
    font-size: 2em;
    color:black;
    text-align: center;
}
.input-box {
    position: relative;
    width: 100%;
    height: 50px;
    border-bottom: 2px solid black;
    margin: 30px;
}
.input-box label{
    position: absolute;
    top: 50%;
    left: 5px;
    transform: translateY(-50%);
    font-size: 1em;
    color: black;
    font-weight: 500; 
    pointer-events: none;
    transition: 0.5s;
}
.input-box input:focus~label,
.input-box input:valid~label{
    top: -5px;
}

.input-box input {
    width: 100%;
    height: 100%;
    background: transparent;
    border: none;
    outline: none;
    font-size: 1em;
    color: black;
    font-weight: 600;
    padding: 0 35px 0 5;

}

.input-box .icon{
    position: absolute;
    right: 8px;
    font-size: 1.2em;
    color: black;
    line-height: 57px;
}

.remember-forget{
    font-size: .9em;
    color: black;
    font-weight: 500;
    margin: -15px 0 15px;
    display: flex;
    justify-content: space-between;
}

.remember-forget lable input{
    accent-color: black;
    margin-right: 3px;
}
    
.remember-forget a{
    color: red;
    text-decoration: none;
}

.remember-forget a:hover{
    text-decoration: underline;
}
.btnn{
    width: 100%;
    height: 45px;
    background: black;
    border: none;
    outline: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1em;
    color: white;
    font-weight: 500;
}

.login-register{
    font-size: .9em;
    color: black;
    text-align: center;
    font-weight: 500;
    margin: 25px 0 10px;
}

.login-register p a{
    color: black;
    text-decoration: none;
    font-weight: 600;
}
.login-register p a:hover{
    text-decoration: underline;
}