HTMLify

:root {
    --primary-color: #19172e;
    --counter-container-size: 9.375rem;
    --container-width: 100%;
    --btn-operator-size: 2.5rem;
}

@font-face {
    font-family: "sans";
    src: url(font/sans.ttf);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    user-select: none;
    font-family: "sans";
}

body {
    background: var(--primary-color);
    color: white;
    position: relative;
    min-height: 95vh;
    padding-bottom: 5rem;
}

a {
    color: white;
}

button {
    color: white;
    border: none;
    cursor: pointer;
}

.heading {
    font-size: 2rem;
    margin: 2rem auto;
    width: max-content;
}

.content-wrapper {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: center;
}

.number-counter,
.number-saved {
    width: var(--container-width);
}

.counter-container {
    width: var(--counter-container-size);
    height: var(--counter-container-size);
    margin: 1rem auto;
    background: rgba(255, 255, 255, 0.05);
    box-shadow: 0 15px 25px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(20px);
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    position: relative;
    border-radius: 1rem;
}

.counter {
    font-size: 4rem;
}

.btn-operator {
    width: var(--btn-operator-size);
    height: var(--btn-operator-size);
    position: absolute;
    font-size: 1.2em;
    background: white;
    color: rgb(34, 34, 34);
    border-radius: 3.125rem;
}

.increase {
    bottom: 10%;
    right: -15%;
}

.decrease {
    bottom: -15%;
    right: 10%;
}

.btn {
    display: block;
    background: #333333;
    padding: 1.25rem;
    margin: 2.5rem auto;
    width: fit-content;
    border-radius: 8px;
}

.btn:active {
    background: rgb(30, 142, 62);
}

.number {
    display: flex;
    height: 100%;
    flex-wrap: wrap;
}

.num {
    color: white;
    margin: 0.625rem;
    font-size: 1.125rem;
    align-self: center;
}

footer {
    display: flex;
    justify-content: space-around;
    align-items: center;
    text-align: center;
    font-size: 1rem;
    padding: 0.313rem;
    line-height: 3vh;
    position: absolute;
    bottom: 0;
    width: 100%;
}



@media screen and (min-width : 635px) {

    :root {
        --counter-container-size: 12rem;
        --btn-operator-size: 3rem;
    }

    .num {
        font-size: 1.4rem;
    }
}

@media screen and (min-width:835px) {

    :root {
        --counter-container-size: 12.5rem;
        --btn-operator-size: 3.5rem;
        --container-width: 50%;
    }

    .num {
        font-size: 1.5rem;
    }

    .content-wrapper {
        flex-direction: row;
        justify-content: space-evenly;
        align-items: flex-start;
    }  
     
}

@media screen and (min-width:1152px) {

    :root {
        --counter-container-size: 14rem;
        --btn-operator-size: 3.8rem;
    }

    .num {
        font-size: 2rem;
    }
}