continuwuity/src/web/pages/resources/common.css

:root {
    color-scheme: light;
    --font-stack: sans-serif;

    --background-color: #fff;
    --text-color: #000;
    --secondary: #666;
    --bg: oklch(0.76 0.0854 317.27);
    --panel-bg: oklch(0.91 0.042 317.27);
    --c1: oklch(0.44 0.177 353.06);
    --c2: oklch(0.59 0.158 150.88);

    --name-lightness: 0.45;
    --background-lightness: 0.9;

    --background-gradient:
        radial-gradient(42.12% 56.13% at 100% 0%, oklch(from var(--c2) var(--background-lightness) c h) 0%, #fff0 100%),
        radial-gradient(42.01% 79.63% at 52.86% 0%, #d9ff5333 0%, #fff0 100%),
        radial-gradient(79.67% 58.09% at 0% 0%, oklch(from var(--c1) var(--background-lightness) c h) 0%, #fff0 100%);

    --normal-font-size: 1rem;
    --small-font-size: 0.8rem;

    --border-radius-sm: 5px;
    --border-radius-lg: 15px;

    @media (prefers-color-scheme: dark) {
        color-scheme: dark;
        --text-color: #fff;
        --secondary: #888;
        --bg: oklch(0.15 0.042 317.27);
        --panel-bg: oklch(0.24 0.03 317.27);

        --name-lightness: 0.8;
        --background-lightness: 0.2;

        --background-gradient:
            radial-gradient(
                42.12% 56.13% at 100% 0%,
                oklch(from var(--c2) var(--background-lightness) c h) 0%,
                #12121200 100%
            ),
            radial-gradient(55.81% 87.78% at 48.37% 0%, #000 0%, #12121200 89.55%),
            radial-gradient(
                122.65% 88.24% at 0% 0%,
                oklch(from var(--c1) var(--background-lightness) c h) 0%,
                #12121200 100%
            );
    }
}

* {
    box-sizing: border-box;
}

body {
    display: grid;
    margin: 0;
    padding: 0;
    place-items: center;
    min-height: 100vh;

    color: var(--text-color);
    font-family: var(--font-stack);
    line-height: 1.5;
}

html {
    background-color: var(--bg);
    background-image: var(--background-gradient);
    font-size: var(--normal-font-size);
}

footer {
    padding-inline: 0.25rem;
    height: max(fit-content, 2rem);

    .logo {
        width: 100%;
        height: 64px;
    }
}

p {
    margin: 1rem 0;
}

em {
    color: oklch(from var(--c2) var(--name-lightness) c h);
    font-weight: bold;
    font-style: normal;
}

small {
    color: var(--secondary);
}

small.error {
    display: block;
    color: red;
    font-size: small;
    font-style: italic;
    margin-bottom: 0.5rem;
}

.panel {
    --preferred-width: 12rem + 40dvw;
    --maximum-width: 48rem;

    width: min(clamp(24rem, var(--preferred-width), var(--maximum-width)), calc(100dvw - 3rem));
    border-radius: var(--border-radius-lg);
    background-color: var(--panel-bg);
    padding-inline: 1.5rem;
    padding-block: 1rem;
    box-shadow: 0 0.25em 0.375em hsla(0, 0%, 0%, 0.1);

    &.narrow {
        --preferred-width: 12rem + 20dvw;
        --maximum-width: 36rem;

        input, button {
            width: 100%;
        }
    }
}

label {
    display: block;
}

input, button {
    display: inline-block;
    padding: 0.5em;
    margin-bottom: 0.5em;

    font-size: inherit;
    font-family: inherit;
    color: white;
    background-color: transparent;

    border: none;
    border-radius: var(--border-radius-sm);
}

input {
    border: 2px solid var(--secondary);

    &:focus-visible {
        outline: 2px solid var(--c1);
        border-color: transparent;
    }
}

button {
    background-color: var(--c1);
    transition: opacity .2s;

    &:enabled:hover {
        opacity: 0.8;
        cursor: pointer;
    }
}

h1 {
    margin-top: 0;
    margin-bottom: 0.67em;
}

@media (max-width: 425px) {
    main {
        padding-block-start: 2rem;
        width: 100%;
    }

    .panel {
        border-radius: 0;
        width: 100%;
    }
}

@media (max-width: 799px) {
    input, button {
        width: 100%;
    }
}