popup.css

* {
    padding: 0;
    margin: 0;
    color: rgb(61, 4, 61);
    font-weight: bold;
    font-family: Cambria, Cochin, Georgia, Times, 'Times New Roman', serif;
}

html {
    font-size: 62.5%;
}

body {
    background-color: rgb(241, 219, 240);
    width: 500px;
    height: 500px;
}

.cont {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: 3rem;
}

.cont p {
    text-align: center;
    font-size: 3rem;
}

.cont img {
    width: 5rem;
    height: 5rem;
    margin: 1rem;
    border-radius: 3rem;
}

.container {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    margin-top: 3rem;
    font-size: 2rem;
}

.cont2 {
    width: 50vw;
    height: 60vh;
    background-color: rgb(37, 240, 179);
    border-radius: 3rem;
}

.cont2 p {
    margin-top: 3rem;
    text-align: center;
}

.cont3 {
    text-align: center;
    align-items: center;
    justify-content: center;
}

.cont3 #day {
    margin-top: 5rem;
}

.cont3 #res,
#day {
    margin-top: 2rem;
    height: 3rem;
    background-color: rgb(243, 223, 243);
    width: 15rem;
    border: none;
    text-align: center;
    margin-left: 1rem;
    border-radius: 1rem;
}

.cont3 p {
    margin: 1rem;
    display: inline-block;
    font-size: 1.7rem;
    margin-bottom: 2rem;
}

.btn {
    margin-top: 2rem;
}

button {
    width: 11rem;
    height: 3.5rem;
    color: white;
    font-size: 1.6rem;
    font-weight: lighter;
    margin-right: 1rem;
    border: none;
}

#btn1:hover {
    cursor: pointer;
    background-color: #2eeb27;
    color: black;
}

#btn2:hover {
    cursor: pointer;
    background-color: red;
    color: black;
}

#btn1 {
    background-color: green;
}

#btn2 {
    background-color: #ec1a12;
}


/*Media Query*/
@media(max-width:998px) {
    html {
        font-size: 55%;
    }
}

@media(max-width:768px) {
    html {
        font-size: 39%;
    }

    .cont2 {
        width: 100vw;
        height: 60vh;
    }

    input::placeholder {
        font-size: 1.5rem;
    }
}

@media(max-width:300px) {
    html {
        font-size: 25%;
    }

    input::placeholder {
        font-size: 1.8rem;
    }
}