styles.css

@import url('https://fonts.googleapis.com/css2?family=Poppins: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');

/* Themes */
:root {
    --box-shadow:
    0px 0px 1.8px rgba(0, 0, 0, 0.16),
    0px 0px 5.7px rgba(0, 0, 0, 0.23),
    0px 0px 14.6px rgba(0, 0, 0, 0.3),
    0px 0px 32px rgba(0, 0, 0, 0.46);

}
:root.light {
    --background-img: url("images/background-light.jpg");
    --logo-img: url("images/logo-light.svg");
    --accent-one: #FFF6EA;
    --accent-two: #F7E9D7;
    --accent-three: #EBD8C3;
    --accent-four: #FFEEEE;

    --font-color: black;
    --input-text-color: var(--font-color);
    --logo-color: white;
    --logo-background-color: rgba(0, 0, 0, 0.8);
}
:root.dark {
    --background-img: url("images/background-dark.jpg");
    --logo-img: url("images/logo-dark.svg");
    --accent-one: #7D5A50;
    --accent-two: #B4846C;
    --accent-three: #E5B299;
    --accent-four: #FCDEC0;

    --font-color: #FCDEC0;
    --input-text-color: var(--accent-one);
    --logo-color: black;
    --logo-background-color: rgba(255, 255, 255, 0.5);
}

/* Global */
* {
    margin: 0;
    padding: 0;
    font-family: 'Poppins', sans-serif;
    color: var(--font-color);
}

body {
    height: 100%;
}

/* Main wrapper */
#wrapper {
    display: flex;
    height: 100%;
    flex-direction: row;
}

/* Background */
#wrapper__background {
    position: relative;
    display: flex;
    align-items: center;
    width: 40vw;
    overflow: hidden;
}
#logo__container {
    position: absolute;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    height: 10rem;
    background-color: var(--logo-background-color);
}
#logo__image {
    content: var(--logo-img);
    height: 5rem;
    color: "red";
}
#logo__text {
    font-size: 5rem;
    color: var(--logo-color);
    font-weight: 700;
}
#background-image {
    content: var(--background-img);
    height: 100%;
    width: 100%;
    object-fit: cover;
}

/* Form */
#wrapper__form {
    width: 60vw;
    position: relative;
    background-color: var(--accent-one);
}

#info__title {
    padding: 2rem;
    width: 70%;
    margin-top: 4rem;
    margin-bottom: 2rem;
    font-size: 5rem;
    font-weight: 900;
}

#form__container {
    margin: 1rem;
    padding: 1rem;
    padding-bottom: 2rem;
    background-color: var(--accent-two);
    box-shadow: var(--box-shadow);
    border-radius: 1rem;
}
#form__title {
    margin: 1rem;
    font-size: 2rem;
    font-weight: 700;
}
#sign-up__form {
    display: flex;
    flex-wrap: wrap;
    font-weight: 500;
}
.input__container {
    display: flex;
    flex-direction: column;
    flex: 40%;
    margin: 1rem;
}
.form__input {
    padding: 1rem;
    font-weight: 300;
    background-color: var(--accent-three);
    color: var(--input-text-color);
    border: none;
    border-radius: 1rem;

    transition: transform 0.2s;
}
.form__input:hover {
    transform: scale(1.03);
}
.form__input:focus {
    transform: scale(1.03);
}

#submit__button {
    margin: 1rem;
    margin-left: 2rem;

    padding: 0.7rem;
    padding-left: 2rem;
    padding-right: 2rem;

    background-color: var(--accent-three);
    border: none;
    font-weight: 500;
    font-size: 1rem;
    border-radius: 1rem;

    transition: transform 0.2s;
}
#submit__button:hover {
    transform: scale(1.1);
    cursor: pointer;
}
#submit__button:focus {
    transform: scale(1.1);
}

#login-text {
    position: relative;
    left: 0;
    bottom: 0;
    margin: 1rem;
    margin-left: 2rem;
    font-weight: 300;
    font-size: 1.1rem;
    font-style: italic;
}

#theme-toggle {
    position: fixed;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 5rem;
    width: 5rem;
    border-radius: 100%;
    background-color: var(--accent-three);

    bottom: 0;
    right: 0;
    margin: 1rem;

    transition: transform 0.2s;
}
#theme-toggle:hover {
    transform: scale(1.1);
    cursor: pointer;
}
#theme-toggle > p {
    font-size: 0.8rem;
    font-weight: 600;
}

/*
  Responsive design
*/

@media only screen and (max-width: 800px) {
    body {
        background-color: var(--accent-one);
    }

    #wrapper {
        flex-direction: column;
        width: 100vw;
    }

    #wrapper__background {
        display: none;
    }

    #wrapper__form {
        width: 100vw;
    }

    #submit__button {
        margin-bottom: 3rem;
    }

    #theme-toggle {
        width: 4rem;
        height: 4rem;
        margin-bottom: 2.5rem;
    }
}