style.css

@import url('https://fonts.googleapis.com/css2?family=Dosis:wght@700&display=swap');

html {
    box-sizing: border-box;
    height:100%;
}

*,
*::after,
*::before {
    box-sizing: inherit;
    margin: 0;
    padding: 0;
}

body {
    align-items: center;
    background: linear-gradient(320deg, #ffef78, #63c9b4);
    display: flex;
    font-family: 'Dosis', sans-serif;
    font-display: swap;
    height: inherit;
    justify-content: center;
}

.wrapper {
    flex-basis: 400px;
    height: 540px;
    padding: 20px 35px;

    border-radius: 16px;
    box-shadow: 0 4px 30px rgba(35, 35, 35, .1);
    backdrop-filter: blur(5.5px) ;
    -webkit-backdrop-filter: blur(5.5px);
    background: rgba(255, 255, 255, .30);
    border: 1px solid rgba(255, 255, 255, .34);
}

.screen {
    border-radius: 16px;
    backdrop-filter: blur(5.5px) ;
    -webkit-backdrop-filter: blur(5.5px);
    background: rgba(255, 255, 255, .75);
    border: 1px solid rgba(255, 255, 255, .01);

    color: rgba(35, 35, 35, 1);
    font-size: 35px;
    text-align: end;
    width: 326px;
    overflow: auto;
    padding: 20px;
}

.calc-button-row {
    display: flex;
    justify-content: space-between;
    margin: 5% 0;
}

.calc-button {
    border-radius: 16px;
    backdrop-filter: blur(5.5px) ;
    -webkit-backdrop-filter: blur(5.5px);
    border: 1px solid rgba(255, 255, 255, .01);
    box-shadow: 0 4px 30px rgba(35, 35, 35, .1);
    background: rgba(255, 255, 255, .75);
    color: rgba(35, 35, 35, 1);
    flex-basis: 20%;
    font-family: inherit;
    font-size: 24px;
    height: 65px;
}

.calc-button:last-child {
    background: rgba(255, 158, 12, .84);
    color: rgba(255, 255, 255, 1);
}

.calc-button:last-child:active {
    background: rgba(255, 255, 255, .75);
    color: rgba(35, 35, 35, 1);
}

.calc-button:active {
    background: rgba(255, 158, 12, .64);
    color: rgba(255, 255, 255, 1);
}

.double {
    flex-basis: 47%;
}

.triple {
    flex-basis: 73%;
}