@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@500&family=Charm&display=swap');



/* root styles */
:root{
    --body-background: white;
    --display-background: transparent;
    --button-area-back: transparent;
    --topDisplay-font-color: rgba(0, 0, 0, 0.6);
    --display-font-color: #2f2f2f;
    --input-button-font-color: black;
    --input-button-color: #cccccc;
    --input-button-hover-color: #c7c7c7;
    --number-button-color: #dddddd;
    --button-font: 'Poppins', sans-serif;
    --footer-font-color: rgb(173, 173, 173);
}
/* style for dark mode */
:root.dark{
    --body-background: black;
    --display-background: transparent;
    --button-area-back: transparent;
    --topDisplay-font-color: rgba(255, 255, 255, 0.6);
    --display-font-color: whitesmoke;
    --input-button-font-color: white;
    --input-button-color: #444444;
    --input-button-hover-color: #4d4d4d;
    --number-button-color: #333333;
    --button-font: 'Poppins', sans-serif;
    --footer-font-color: rgb(70, 70, 70);
}
/* get tahoma font from .ttf file */
@font-face {
    font-family: displayFont;
    src: url(fonts/tahoma.ttf);
}


html{ font-size: 16px;}
*{
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}
body{
    background: var(--body-background);
    margin: 0;
}
.container{
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    min-height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
}

/* light and dark mode toggler styles */
.theme{
    width: 100%;
    min-width: 13rem;
    max-width: 33rem;
    display: flex;
    justify-content: flex-end;
    margin-top: 0.5rem;
}
.toggle{
    background: rgb(185, 185, 185);
    height: 10px;
    width: 50px;
    border-radius: 10px;
    padding: 10px 0;
    position: relative;
    display: flex;
    align-items: center;
}
.toggler{
    fill: white;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 20px;
    height: 20px;
    background: rgb(51, 51, 51);
    position: absolute;
    border-radius: 50%;
}
.dark .toggler{
    fill: black;
    background: white;
    transform: translateX(30px);
}


/* calculator styles */
.calculator{
    min-width: 15rem;
    max-width: 35rem;
}

/* calculator display styles */
.input-area{
    background: var(--display-background);
    padding: 0.5rem 0.5rem 1rem;
    font-family: displayFont, 'Tahoma', sans-serif;
}
#topDisplay{
    background: transparent;
    color: var(--topDisplay-font-color);
    width: 100%;
    text-align: right;
    font-size: 1.3rem;
    border: 0;
    outline: 0;
}
#display{
    background: transparent;
    color: var(--display-font-color);
    width: 100%;
    text-align: right;
    font-size: 2.7rem;
    border: 0;
    outline: 0;
}

/* calculator button styles */
.button-area{
    width: 100%;
    height: 65vh;
    min-height: 15rem;
    background: var(--button-area-back);
    padding: 2px;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-gap: 1.5vh;
}
.input-button{
    color: var(--input-button-font-color);
    text-align: center;
    font-size: 1.4rem;
    font-family: var(--button-font);
    background: var(--input-button-color);
    position: relative;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    border-radius: 40px;
    user-select: none;
}
.input-button.clicked{
    animation: clickAnimation 100ms ease-out;
}
@keyframes clickAnimation {
    0%{transform: scale3d(.9,.9,.9);}
    40%{transform: scale3d(1.3,1.3,1.3);}
    100%{transform: scaleX(1);}
}
.numberButton{
    background: var(--number-button-color);
}
.operationBut, #equalBut{
    background: rgb(255, 102, 0);
}
#squareBut, #sqrtBut, #oneDivided{
    font-family: 'Charm', serif;
    font-weight: bold;
}
sup{
    font-size: 17px;
    position: relative;
    top: -5px;
}
sub{
    position: relative;
    top: 5px;
}


/* signature of the maker of this calculator */
footer{
    color: var(--footer-font-color);
    font-family: 'Poppins';
    letter-spacing: 1px;
}
footer > a{
    color: inherit;
}


/* style only for laptop or desktop */
@media screen and (min-width: 768px) {    
    html{ font-size: 20px; }
    
    .input-button:hover{
        background: var(--input-button-hover-color);
    }
    .operationBut:hover, #equalBut:hover{
        background: rgb(255, 81, 0);
    }
    @keyframes clickAnimation {
        40%{transform: scale3d(1.1,1.2,1.1);}
    }

    footer{
        letter-spacing: 5px;
    }
}