styles.css

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, Helvetica, sans-serif;
    letter-spacing: 1px;
}

body {
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    display: grid;
    place-items: center;
    background-color: darkslategray;
}

.github {
    position: absolute;
    right: 0;
    top: 0;
    padding: 10px;
}

.github {
    background-color: rgb(17, 17, 17);
    border-radius: 0 0 10px 10px;
}

.github a {
    color: #dfdadf;
}

.github a i {
    color: white;
    margin-right: 10px;
}

.container {
    padding: 20px;
    text-align: center;
    box-shadow: 0 0 15px #000;
    border-radius: 25px;
    background-color: rgb(25, 31, 31);
    box-shadow: 6px 6px 0px #0c0c0c,
        -6px -6px 0px #0c0c0c;
}

.container {
    box-shadow: inset 4px 4px 2px #686666,
        inset -4px -4px 2px #666565;
}

.box-text {
    color: aliceblue;
    margin: 5px;
}

.box-text h1 {
    text-align: left;
    font-size: 23px;
    font-family: Impact, 'Arial Narrow Bold', sans-serif;
    outline: #000;
}

.box-text p {
    font-family: 'Courier New', monospace, Verdana, Tahoma, sans-serif;

}

.box-text small {
    float: right;
    font-family: 'Arial Narrow Bold', sans-serif;
    font-size: 12px;
}

.display-sc input {
    width: 280px;
    height: 100px;
    border: #0c0c0c;
    outline: green;
    padding: 10px;
    border-radius: 5px;
    margin: 10px;
    background-color: rgb(27, 85, 55);
    color: rgb(236, 229, 229);
    font-size: 13px;
    cursor: pointer;
    box-shadow: inset 8px 8px 3px #0c0c0c,
        inset -8px -8px 3px #0c0c0c;
}

@font-face {
    font-family: 'casio-calculator-font';
    src: url('font/casio-calculator-font.ttf') format('truetype');
    font-weight: normal;
    font-style: normal;
}

.display-sc input {
    font-family: 'casio-calculator-font';
}

input::placeholder {
    color: azure;
}

button {
    width: 45px;
    height: 35px;
    margin: 3px;
    background-color: lightslategray;
    color: aliceblue;
    font-size: 17px;
    border-radius: 5px;
    box-shadow: 1px 1px 0px #000;
}

.support-btns {
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
}

.support-btns button {
    width: 32px;
    height: 32px;
    font-size: 14px;
    background: linear-gradient(145deg, #171717, #272627);
    border-radius: 50%;
    outline: none;
    border: 2.5px #090909 solid;
    box-shadow: inset 1px 1px 0px #7d7c7e;
    margin: 10px;
}

.support-btns button:active {
    transform: translateX(4px);
}

.support-btns .bg {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #171717;
    border-radius: 150px;
    margin: 15px;
    height: 32px;
    box-shadow: inset 2px 2px 2px#000, inset -2px -2px 2px;
}

.funct-keys button {
    width: 35px;
    height: 25px;
    font-size: 14px;
    background-color: rgb(37, 54, 54);
    margin-top: 5px;
}

.basic-keys {
    margin: 5px;
}

.row span {
    background-color: #0c0c0c;
    height: 100px;
}

#left-btn {
    border-top-left-radius: 100px;
    border-bottom-left-radius: 100px;
    background: linear-gradient(145deg, #171717, #272627);
}

#right-btn {
    border-top-right-radius: 100px;
    border-bottom-right-radius: 100px;
    background: linear-gradient(145deg, #171717, #272627);
}

button:active {
    background-color: aliceblue;
    transform: translate(2px, 3px);
}

.funct {
    background-color: rgb(134, 190, 50);
}


@media screen and (min-width: 1200px) {
    .box-test small {
        display: none;
    }

    .container {
        padding: 20px;
        border-radius: 20px;
    }

    .github {
        top: 0;
        right: 0;
    }

}

@media screen and (min-width: 768px) {
    .container {
        padding: 20px;
        border-radius: 20px;
    }

    .github {
        top: 0;
        right: 0;
    }
}

@media screen and (max-width: 768px) {
    .github {
        top: 0;
        right: 0;
    }

    .container {
        padding: 20px;
        border-radius: 20px;
    }
}