index.css

/* @import url('https://fonts.googleapis.com/css2?family=Fira+Sans+Condensed:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800;1,900&display=swap'); */

* {
    font-family: 'Fira Sans Condensed', sans-serif;
}

body {
    --background-color: #dde8f0;
    --divs-color: white;
    --text-color: white;
    --signin-color: black;
    --box-shadow_1: 0 0 20px #eee;
    /* --error-message: #750317; */
    --error-message: red;
    --signup-text: black;
    --switch-text: black;
    --input-color: white;
    --btn-sub-colors: linear-gradient(to right, #009cbf 0%, #26D0CE  51%, #1A2980  100%);

    background: url('images/background-login-dark-trans.png') no-repeat center fixed;
    background-size: cover;
    background-color: var(--background-color);
    height: 100%;  
    overflow: hidden;
    margin:0;

}

body.dark {
    --background-color: #333;
    --divs-color: #444444;
    --text-color: #EEEEEE;
    --signin-color: #EEEEEE;
    --box-shadow_1: none;
    /* --error-message: rgb(212, 182, 182); */
    --error-message: rgb(252, 76, 76);
    --signup-text: lightgrey;
    --switch-text: white;
    --input-color: #EEEEEE;
    --btn-sub-colors: linear-gradient(to right, #009cbf 40%, #26d0cd59  51%, #1A2980  100%);

    background-color: var(--background-color);
}


.wrapper {
    display: flex;
    flex-direction: row;
    position: relative;
    top: 200px;
}

.empty-div {
    order: 1;
    width: 60%;
}

.login-div {
    order:2;
    padding-right: 15px;
    display: flex;
    flex-direction: column;
}

.logo {
    max-width: 280px;
    max-height: 280px;
}

.logo-div {
    width: 39.5%;
    padding-left: 21%;
}

.div-form {
    background-color:var(--divs-color);
    text-align: center;
    width: 450px;
    border-radius: 15px;
    box-shadow: rgba(0, 0, 0, 0.24) 0px 3px 8px; 
}

.label-signin {
    color: var(--signin-color);
    font-size: 2rem;
    font-weight: 600;
}

.input-login {
    border-radius: 15px;
    border: 2px solid #009cbf;
    background-color: var(--input-color);
    padding: 20px;
    width: 50%;
    height: 1px;
    font-size: 0.9rem;
    outline: none;
    font-size: 100%;
}

.btn {
    margin: 10px;
    padding: 10px 30px;
    text-align: center;
    text-transform: uppercase;
    transition: 0.5s;
    background-size: 200% auto;
    color: var(--text-color);            
    box-shadow: var(--box-shadow_1);
    border-radius: 10px;
    display: block;
    border: 2px solid var(--text-color);
    cursor: pointer;
    margin: 0 auto;
    display: table;
    font-size: 1rem;
    background-image: var(--btn-sub-colors);
}

.btn:hover {
    background-position: right center;
    color: #fff;
    text-decoration: none;
}

.login_error {
    text-align: center;
    font-size: 0.9rem;
    color: var(--error-message);
}

.signup-link {
    color: var(--signup-text);
}

.signup-link a {
    color: var(--signup-text);
}

.dark-light {
    position: absolute;
    left:0;
    width: 100%;
}

.drk-lght-button {
    float: right;
    margin: 10px;
    padding: 10px 30px;
    text-align: center;
    text-transform: uppercase;
    color: var(--switch-text);            
    border-radius: 10px;
    display: block;
    border: none;
    background: none;
    cursor: pointer;
    margin: 0 auto;
    display: table;
    font-size: 1rem;
}

.drk-lght-button img {
    vertical-align: middle;
}

/* mobile */
@media all and (max-width:414px) {

    .wrapper {
        /* display: flex;
        flex-direction: row;
        position: relative; */
        top: 90px;
    }


    .div-form {
        /* background-color:var(--divs-color);
        text-align: center;
        width: 450px;
        border-radius: 15px;
        box-shadow: rgba(0, 0, 0, 0.24) 0px 3px 8px;  */

        width: 100vw;
    }

    .logo-div {
        width: 100vw;
        padding-left: 15%;
    }
    

}