:root {
    --switch-height: 30px;
    --switch-width: calc(var(--switch-height) * 2);

    --dark-background: #333;
    --dark-text: white;

    --light-background: white;
    --light-text: black;

    --background-color: var(--light-background);
    --text-color: var(--light-text);
}

body,
html,
main {
    height: 100%;
}

body {
    font-family: Arial, Helvetica, sans-serif;
}

main {
    width: 100%;
    background-color: var(--background-color);
    color: var(--text-color);
    position: absolute;
    z-index: 0;
    justify-content: center;
    flex-direction: column;
    align-items: center;
    display: flex;
    transition: color 250ms, background-color 250ms;
    box-sizing: border-box;
}

main > * {
    max-width: 768px;
}

h1 {
    font-weight: bold;
    font-size: 1.8rem;
    margin-bottom: 1.8rem;
}

bold {
    font-weight: bold;
}

p {
    margin-bottom: 1rem;
    line-height: 1.5rem;
}

[type='checkbox'] {
    display: none;
}

.switch {
    position: absolute;
    top: 3%;
    width: var(--switch-width);
    height: var(--switch-height);
    text-align: right;
    font-size: 1.2rem;
    vertical-align: middle;
    line-height: var(--switch-height);
    user-select: none;
    display: flex;
    justify-content: space-between;
    cursor: pointer;
    opacity: 1;
    left: 80%;
}

[type='checkbox']:checked + .switch.daily::before {
    transform: translateX(calc(200% - var(--switch-height)));
}

[type='checkbox']:checked + .switch.nightly::before {
    transform: translateX(calc(-200% + var(--switch-height)));
}

.switch::before {
    content: '';
    width: var(--switch-height);
    height: var(--switch-height);
    border-radius: var(--switch-height);
    background-color: white;
    position: absolute;
    z-index: 2;
    transition: transform 250ms;
    top: 0;
}

.daily.switch::before {
    left: 0%;
}

.nightly.switch::before {
    right: 0%;
}

.switch::after {
    content: '';
    width: var(--switch-width);
    height: var(--switch-height);
    border-radius: 60px;
    background-color: gray;
    position: absolute;
    left: 0;
    top: 0;
    z-index: 1;
}

[type='checkbox']:checked + .nightly.switch::after {
    background-color: gray;
}

.night,
.day {
    z-index: 3;
}

.switch.daily > .night {
    opacity: 0;
}

.switch.nightly > .day {
    opacity: 0;
}

[type='checkbox']:checked + .switch.daily::after,
[type='checkbox'] + .switch.nightly::after {
    background-color: #4cda64;
}

[type='checkbox']:checked + .switch.daily > .day {
    opacity: 0;
}

[type='checkbox']:checked + .switch.daily > .night {
    opacity: 1;
}

[type='checkbox']:checked + .switch.nightly > .day {
    opacity: 1;
}

[type='checkbox']:checked + .switch.nightly > .night {
    opacity: 0;
}

#day-switch[type='checkbox']:checked ~ main {
    --background-color: var(--dark-background);
    --text-color: var(--dark-text);
}

#night-switch[type='checkbox']:checked ~ main {
    --background-color: var(--light-background);
    --text-color: var(--light-text);
}

.switch.nightly {
    display: none;
}

.switch.daily {
    display: flex;
}

@media (prefers-color-scheme: dark) {
    :root {
        --background-color: var(--dark-background);
        --text-color: var(--dark-text);
    }

    .switch.nightly {
        display: flex;
    }

    .switch.daily {
        display: none;
    }
}

@media (max-width: 769px) {
    main {
        padding-left: 30px;
        padding-right: 30px;
    }
}

@media (max-width: 486px) {
    main {
        padding-left: 30px;
        padding-right: 30px;
    }
}