style.css

@import url('https://fonts.googleapis.com/css2?family=Poppins:ital,wght@0,700;1,400;1,800&display=swap');

* {
    box-sizing: border-box;
    margin: 0;
    overflow-x: hidden;
}

body {
    font-family: 'Poppins', sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background-color: #f0f0f0;
    width: 100vw;
}

.container {
    width: 842px;
    height: 651px;
    background-color: white;
    border-radius: 2rem 2rem 14rem 2rem;
    padding: 3rem;
    position: relative;
}

.inputs {
    width: 634px;
    display: flex;
    justify-content: start;
    gap: 3rem;
}

.inputEl {
    display: flex;
    flex-direction: column;
    gap: .7rem;
}

.inputEl label {
    font-size: 15px;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    font-family: inherit;
    color: hsl(0, 1%, 44%);
}

.inputEl input {
    border-radius: 5px;
    padding: 15px 20px;
    font-size: 25px;
    max-width: 150px;
    font-family: inherit;
    border: 1px solid gray;
}

.error-message {
    font-size: 10px;
    color: red;
}

.line {
    border: 1px solid hsl(0, 0%, 86%);
    margin-top: 3rem;
}

.btn {
    background: #874cfc;
    border-radius: 50%;
    width: 97px;
    height: 97px;
    display: flex;
    justify-content: center;
    align-items: center;
    position: absolute;
    top: 165px;
    right: 5%;
    cursor: pointer;
    border: none;
    transition: .3s ease;
}

.btn:hover {
    background-color: hsl(0, 0%, 8%);
}

.stats {
    font-size: 40px;
    margin-top: .5rem;
    font-style: italic;
}

.stats span {
    color: #874cfc;
}

footer {
    font-size: 12px;
    text-align: center;
    bottom: 10px;
}

footer a {
    color: red;
}

@media(max-width:878px) {
    .container {
        width: 95%;
    }
}

@media(max-width:783px) {
    .container {
        padding: 3rem 10px;
        height: auto;
        border-radius: 2rem 2rem 8rem 2rem;
    }

    .inputs {
        width: 100%;
        justify-content: center;
        gap: 1rem;
    }

    .inputEl input {
        padding: 10px 20px;
        max-width: 200px;
    }

    .btn {
        left: 50%;
        top: 170px;
        transform: translateX(-50%);
        width: 70px;
        height: 70px;
    }

    .stats {
        font-size: 25px;
        margin-top: 2rem;
    }
}

@media(max-width:400px) {
    .container {
        height: auto;
    }

    .inputs {
        display: flex;
        flex-direction: column;
        align-items: center;
    }

    .inputEl {
        width: 100%;
    }

    .inputEl input {
        min-width: 100%;
    }

    .btn {
        top: 415px;
    }

    .stats {
        font-size: 18px;
        padding-top: 3rem;
        padding-left: 1rem;
    }

    footer {
        font-size: 8px;
    }
}