/* ensure the page takes over all the webpage */
html {
    height: 100%;
    font-family: Arial, sans-serif;
    margin: 0px;
    padding: 0px;
    align-items: center;
    background: linear-gradient(125deg,
            rgb(255, 255, 255),
            rgb(186, 186, 186));
}

#body {
    border: solid white 5px;
    padding: 8px;
    margin: 15% 30% 10% 30%;
    min-height: 50%;
    display: flex;
    flex-direction: column;
    /* border radius of the calculator body */
    border-radius: 24px;
    /* calculator body background color */
    background: linear-gradient(125deg,
            rgb(255, 197, 197),
            rgb(246, 239, 230),
            rgb(183, 228, 249));
    /* box-shadow: 5px 5px 10px rgba(0, 0, 0, 0.2); */
    box-shadow: 5px 5px 10px rgba(0, 0, 0, 0.2);
}

#display {
    display: flex;
    margin: 8px;
    border: solid white 2px;
    flex-direction: column;
    min-height: 100px;
    /* how much percentage the display takes the space */
    flex: 0.5;
    /* border-radius of the display */
    border-radius: 8px;
    /* display background color */
    background: linear-gradient(125deg,
            rgb(255, 255, 255),
            rgb(241, 241, 241));
    box-shadow: inset 1px 1px 5px rgba(0, 0, 0, 0.2);
}

.displayCell {
    padding: 8px;
}

#inputNumber{
    display: flex;
    flex: 1;
    flex-direction: column;
    align-items: end;
}

#output {
    /* border: solid red; */
    flex:0.4;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    align-items: end;
    padding-bottom: 8px;
}

#btGroup {
    /* how much percentage the buttons take the space */
    flex: 1;
    display: flex;
    flex-direction: column;
}

#btGroup2 {
    /* ensure buttons spread all the way vertically */
    flex: 1;
    display: flex;
}

#btEqual {
    border: solid pink;
}

.bt {
    border: solid white 2px;
    /* border radius of the buttons */
    border-radius: 8px;
    /* ensure bts spread all the way horizontally */
    flex: 1;
    padding: 8px;
    margin: 8px;
    /* buttons background color */
    background: linear-gradient(125deg,
            rgb(255, 255, 255),
            rgb(231, 231, 231));
    box-shadow: 2px 2px 5px rgba(0, 0, 0, 0.2);
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.bt#btEqual {
    flex: 3;
}

.copyright {
    text-align: center;
    color: gray;
}