@import url('https://fonts.googleapis.com/css2?family=League+Spartan:wght@100..900&display=swap');

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

:root {
    --main-bg: hsl(222, 26%, 31%);
    --keypad-bg: hsl(223, 31%, 20%);
    --screen-bg: hsl(224, 36%, 15%);

    --key-blue-bg: hsl(225, 21%, 49%);
    --key-blue-shadow: hsl(224, 28%, 35%);
    --key-red-bg: hsl(6, 63%, 50%);
    --key-red-shadow: hsl(6, 70%, 34%);
    --key-light-bg: hsl(30, 25%, 89%);
    --key-light-shadow: hsl(28, 16%, 65%);
    --text-main: #ffffff;
    --text-keys: hsl(221, 14%, 31%);
}

.theme-2 {
    --main-bg: hsl(0, 0%, 90%);
    --keypad-bg: hsl(0, 5%, 81%);
    --screen-bg: hsl(0, 0%, 93%);
    --key-blue-bg: hsl(185, 42%, 37%);
    --key-blue-shadow: hsl(185, 58%, 25%);
    --key-red-bg: hsl(25, 98%, 40%);
    --key-red-shadow: hsl(25, 99%, 27%);
    --key-light-bg: hsl(45, 7%, 89%);
    --key-light-shadow: hsl(35, 11%, 61%);
    --text-main: hsl(60, 10%, 19%);
    --text-keys: hsl(60, 10%, 19%);
}

.theme-3 {
    --main-bg: hsl(268, 75%, 9%);
    --keypad-bg: hsl(268, 71%, 12%);
    --screen-bg: hsl(268, 71%, 12%);
    --key-blue-bg: hsl(281, 89%, 26%);
    --key-blue-shadow: hsl(285, 91%, 52%);
    --key-red-bg: hsl(176, 100%, 44%);
    --key-red-shadow: hsl(177, 92%, 70%);
    --key-light-bg: hsl(268, 47%, 21%);
    --key-light-shadow: hsl(290, 70%, 36%);
    --text-main: hsl(52, 100%, 62%);
    --text-keys: hsl(52, 100%, 62%);
}


.theme-3 .equal-btn {
    color: hsl(198, 20%, 13%);
}

body {
    background-color: var(--main-bg);
    font-family: 'League Spartan', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    overflow: hidden;
}

.calculator {
    width: 100%;
    max-width: 30.3rem;
    padding: 0.6rem;
}

.calc-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    text-align: center;
}

.logo {
    color: var(--text-main);
}

.theme-switcher {
    display: flex;
    align-items: flex-end;
    gap: 1.25rem;
    color: var(--text-main);
}

.theme-label {
    font-size: 0.9rem;
    letter-spacing: 1px;
    margin-bottom: 0.3rem;
}

.toggle-container {
    width: 4.3rem;
}

.toggle-numbers {
    display: flex;
    justify-content: space-around;
    font-size: 0.75rem;
    margin-bottom: 0.3rem;
    font-weight: 700;
}

.toggle-inputs {
    background: var(--keypad-bg);
    height: 1.62rem;
    border-radius: 3.12rem;
    position: relative;
    display: flex;
    align-items: center;
    padding: 0 0.3rem;
}

.toggle-inputs input {
    opacity: 0;
    flex: 1;
    height: 100%;
    cursor: pointer;
    z-index: 2;
    margin: 0;
}

.toggle-slider {
    position: absolute;
    height: 1rem;
    width: 1rem;
    background: var(--key-red-bg);
    border-radius: 50%;
    transition: 0.3s ease;
    left: 0.3rem;
}


#theme1:checked~.toggle-slider {
    left: 0.3rem;
}

#theme2:checked~.toggle-slider {
    left: 1.6rem;
}

#theme3:checked~.toggle-slider {
    left: 3rem;
}


.calc-screen {
    background: var(--screen-bg);
    color: var(--text-main);
    padding: 1.5rem;
    text-align: right;
    font-size: 2.5rem;
    border-radius: 0.6rem;
    margin: 1.5rem 0;
}


.calc-keypad {
    background: var(--keypad-bg);
    padding: 1.5rem;
    border-radius: 0.6rem;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.9rem;
}

.key {
    padding: 0.9rem;
    font-size: 1.75rem;
    border: none;
    border-radius: 0.5rem;
    cursor: pointer;
    background: var(--key-light-bg);
    color: var(--text-dark-blue);
    box-shadow: 0 4px var(--key-light-shadow);
}

.key:active {
    transform: translateY(2px);
    box-shadow: 0 2px var(--key-light-shadow);
}

.del-btn,
.reset-btn {
    background: var(--key-blue-bg);
    color: white;
    box-shadow: 0 4px var(--key-blue-shadow);
    font-size: 1.25rem;
}

.equal-btn {
    background: var(--key-red-bg);
    color: white;
    box-shadow: 0 4px var(--key-red-shadow);
}

.span-two {
    grid-column: span 2;
}

@media (max-width: 480px) {
    body {
        align-items: flex-start;
        padding-top: 2rem;
    }

    .calculator {
        padding: 1rem;
    }

    .logo {
        font-size: 2rem;
    }

    .theme-label {
        font-size: 1rem;
    }

    .toggle-numbers{
        font-size: 1rem;
    }


    .calc-screen {
        font-size: 3rem;
        padding: 1.25rem 1rem;
        margin: 1rem 0;
    }

    .calc-keypad {
        padding: 1.25rem;
        gap: 0.75rem;
    }

    .key {
        padding: 1rem;
        font-size: 1.5rem;
        border-radius: 0.4rem;
    }

    .del-btn,
    .reset-btn {
        font-size: 1rem;
    }

    .equal-btn {
        font-size: 1.25rem;
    }

    .toggle-container {
        width: 3.8rem;
    }

    .toggle-inputs {
        height: 1.4rem;
    }

    .toggle-slider {
        height: 0.85rem;
        width: 0.85rem;
    }

    #theme2:checked ~ .toggle-slider {
        left: 1.45rem;
    }

    #theme3:checked ~ .toggle-slider {
        left: 2.7rem;
    }
}