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

:root {
    --background-color: #3b4764;
    --display-color: #181f32;
    --display-text-color: #ffffff;
    --keyboard-background-color: #242e44;
    --key-default-color: #e9e3db;
    --key-default-shadow-color: #b3a398;
    --key-default-hover-color:  #FFFFFE;
    --key-default-text-color: #4a505f;
    --key-accent-color: #64719b;
    --key-accent-shadow-color: #424d74;
    --key-accent-hover-color: #A2B2E1;
    --key-accent-text-color: #ffffff;
    --key-equal-color: #d14030;
    --key-equal-shadow-color: #912417;
    --key-equal-hover-color: #F96B5B;
    --key-equal-text-color: #ffffff;
}

body {
    margin: 0;
    padding: 0;
    background: var(--background-color);
    font-family: "Spartan", sans-serif;
}

.top {
    margin-bottom: 32px;
    max-height: 44px;
    max-width: 540px;
    display: flex;
    justify-content: space-between;
    line-height: 36px;
    letter-spacing: -0.5333333611488342px;
    text-align: center;
    color: var(--display-text-color);
}

.theme-toggle {
    display: flex;
    justify-content: space-between;
    max-width: 144px;
    margin-right: 1%;
}

.title {
    height: 100%;
    margin: auto 0;
}

.theme {
    position: relative;
    height: 13px;
    font-weight: bold;
    font-size: 13px;
    line-height: 14px;
    letter-spacing: 1px;
    margin: 5% auto;
    padding-right: 5%;
}

.slider {
    max-width: 71px;
    height: 26px;
    -webkit-appearance: none;
    border-radius: 13px;
    outline: none;
    background: var(--keyboard-background-color);  
    padding: 0 5px;
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--key-equal-color);  
    cursor: pointer;
  }

.slider::-webkit-slider-thumb:hover {
    background: var(--key-equal-hover-color);
}

.calculator {
    display: block;
    overflow: hidden;
    margin: 80px auto;
    max-width: 540px;
}

.calculator p {
    position: relative;
    text-align: right;
    font-size: 12px;
    line-height: 13px;
    letter-spacing: 15px;
    font-weight: bold;
    margin-bottom: 5px;
    color: var(--display-text-color);
}

.display {
    max-width: 540px;
    height: 128px;
    line-height: 128px;
    background: var(--display-color);
    color: var(--display-text-color);
    font-size: 42px;
    border-radius: 8px;
    margin-bottom: 25px;
    padding: 0 45px;
    text-align: right;
    box-sizing: border-box;
}

.keys {
    background: var(--keyboard-background-color);
    color: var(--key-default-color);
    height: 100%;
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr;
    grid-template-columns: repeat(4, 1fr);
    grid-row-gap: 7%;
    grid-column-gap: 4%;
    padding: 32px;
    padding-bottom: 92px;
    margin-bottom: 96px; 
    overflow: hidden;
    border-radius: 10px;
}

.keys button.long.accent {
    grid-column: 1/3;
}

.keys button.long.equal {
    grid-column: 3/5;
}

.keys button {
    border-radius: 8px;
    background: var(--key-default-color);
    outline: none;
    border: none;
    box-shadow: 0 5px 0 var(--key-default-shadow-color);
    color: var(--key-default-text-color);
    font-size: 28px;
    font-weight: bold;
    line-height: 50px;
    cursor: pointer;
    text-transform: uppercase;
}

.keys button:active {
    box-shadow: none !important;
    transform: translateY(5px);
}

.keys button:hover {
    background: var(--key-default-hover-color);
}


.keys button.accent {
    background: var(--key-accent-color);
    color: var(--key-accent-text-color);
    box-shadow: 0 5px 0 var(--key-accent-shadow-color);
}

.keys button.accent:hover {
    background: var(--key-accent-hover-color);
}

.keys button.equal {
    background: var(--key-equal-color);
    color: var(--key-equal-text-color);
    box-shadow: 0 5px 0 var(--key-equal-shadow-color);
}

.keys button.equal:hover {
    background: var(--key-equal-hover-color);
}

/*moblie version and tablet*/
@media only screen and (max-width:550px) {

    .calculator {
        margin: 5%;
    }
}

@media only screen and (max-width: 485px) {

    .calculator {
        margin: auto;
        max-width: 327px;
        
    }

    .display {
        font-size: 32px;
        
    }

    .keys button {
        line-height: 31px;
        min-height: 64px;
        min-width: 60px;
    }

    .keys button.long {
        font-size: 16px;
        line-height: 18px;
        letter-spacing: -0.2666666805744171px;
        text-align: center;
    }

    .keys button.accent {
        font-size: 16px;
        line-height: 18px;
        letter-spacing: -0.2666666805744171px;
        text-align: center;
    }

    .keys {
        padding-bottom: 112px;
    }

}

@media only screen and (max-width: 350px) {

    .calculator {
        margin: 5%;
    }

    .keys button {
        min-height: 54px;
        min-width: 50px;
    }
}

@media only screen and (max-width: 315px) {
    .keys button {
        min-height: 34px;
        min-width: 30px;
    }

    .keys button.long {
        font-size: 10px;
        line-height: 12px;
    }

    .keys button.accent {
        font-size: 10px;
        line-height: 12px;
    }

    .keys {
        padding: 5%;
        padding-bottom: 72px;
    }
}