* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    background: linear-gradient(to left top, blue, violet);
}

.container {
    width: 100%;
    max-width: 350px;
    min-width: 280px;
    border-radius: 3ch;
    padding: 20px;
    background: rgba(255, 255, 255, 0.4);
    box-shadow: 5px 5px 20px 3px rgb(0, 0, 0);
    backdrop-filter: blur(100px);
    border: none;
}

.parentbox {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(5, 1fr);    
    gap: 10px;
    border: none;
    margin-top: 15px;
}

.box {
    background-color: rgb(255, 255, 255);
    aspect-ratio: 1/1;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: clamp(18px, 4vw, 26px);
    font-family: 'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
    box-shadow: 5px 5px 5px 0px rgba(116, 3, 255, 0.618);
    transition: all 0.2s ease;
    width: 100%;
}

#ans {
    grid-column: span 2;
    border-radius: 3ch;
    background-color: rgb(255, 136, 0);
    aspect-ratio: unset;
}

#ac, #del, #percentage, #div, #mul, #add, #sub {
    color: rgb(0, 13, 255);
}

input {
    width: 100%;
    height: 10vh;
    max-height: 100px;
    min-height: 60px;
    text-align: right;
    margin-bottom: 10px;
    border-radius: 1ch;
    font-size: clamp(24px, 6vw, 3rem);
    padding: 0 10px;
    border: none;
    background-color: rgb(240, 222, 197);
}

.box:hover {
    background-color: rgba(128, 128, 128, 0.8);
}

/* Media query for very small screens */
@media (max-width: 300px) {
    .container {
        padding: 10px;
    }
    
    .box {
        font-size: 16px;
    }
    
    input {
        font-size: 20px;
    }
}