/* Invent CSS — default stylesheet.
 *
 * Override any variable by re-declaring it inside a :root {} block
 * in your own stylesheet, loaded after this one.
 *
 * Note: --breakpoint-sm (600px) is used in @media rules below.
 * CSS custom properties cannot be referenced inside @media queries,
 * so this value is hardcoded.  Update the comment and the media
 * query together if you change the breakpoint.
 */

/* === Variables: light theme (default) === */

:root {
    color-scheme: light;

    /* Typography. */
    --font: 'Roboto', sans-serif;
    --font-mono: monospace, monospace;
    --line-height: 1.5;
    --h1-size: 3.5rem;
    --h2-size: 3rem;
    --h3-size: 2.5rem;
    --h4-size: 2rem;
    --h5-size: 1.5rem;
    --h6-size: 1.25rem;

    /* Layout. */
    --page-width: 80%;
    --page-max-width: 960px;

    /* Background overlays.
     * These can be used to apply a semi-transparent overlay to background
     * images, improving contrast and readability. */
    --bg-image-overlay: rgba(255, 255, 255, 0.66); /* pale wash. */


    /* Borders and shape. */
    --border-width: 2px;
    --border-radius: 4px;
    --border-radius-lg: 8px;
    --spacing-sm: 8px;
    --spacing-md: 12px;
    --spacing-lg: 16px;

    /* Transitions (suppressed by prefers-reduced-motion below). */
    --transition-speed: 0.2s;
    --transition-speed-button: 235ms ease-in-out 0s;
    --transition-speed-slow: 0.4s;
    --transition-speed-fast: 0.1s;

    /* Colours: base. */
    --color-body: #111;
    --main-background: white;

    /* Colours: links. */
    --link: #085aa5;
    --link-hover: #208ef3;
    --link-visited: #5a2a8a;

    /* Colours: semantic. */
    --primary: #41403e;
    --secondary: #0b74d5;
    --success: #4a9e6a;
    --warning: #e0a030;
    --danger: #a7342d;
    --muted: #868e96;

    /* Colours: light variants. */
    --primary-light: #cdcccb;
    --secondary-light: #d8ebfd;
    --success-light: #d0e8d6;
    --warning-light: #f5e6c0;
    --danger-light: #f0cbc9;
    --muted-light: #e6e7e9;

    /* Colours: active variants. */
    --primary-active: #b4b3b0;
    --secondary-active: #a7d3fa;
    --success-active: #a8d4b5;
    --warning-active: #e8cc88;
    --danger-active: #e6a5a1;

    /* Colours: dark variants. */
    --primary-dark: #1a1918;
    --secondary-dark: #053a6a;
    --success-dark: #1e5a32;
    --warning-dark: #8a5c10;
    --danger-dark: #5a1410;
    --muted-dark: #313538;

    /* Colours: neutral. */
    --white: white;
    --black: black;

    /* Colours: text. */
    --primary-text: #272625;
    --secondary-text: #085aa5;
    --success-text: #2a5e38;
    --warning-text: #7a5510;
    --danger-text: #7f2722;
    --muted-text: #6c757d;
}

/* === Variables: dark theme overrides === */

@media (prefers-color-scheme: dark) {
    :root {
        color-scheme: dark;

        /* Background overlays. */
        --bg-image-overlay: rgba(0, 0, 0, 0.66); /* dark wash. */


        /* Colours: base. */
        --color-body: #e0e0e0;
        --main-background: #1a1a1e;

        /* Colours: links. */
        --link: #4da8f0;
        --link-hover: #7cc4ff;
        --link-visited: #c084fc;

        /* Colours: semantic. */
        --primary: #9a9895;
        --secondary: #3d9cf0;
        --success: #5fb87e;
        --warning: #e8b040;
        --danger: #cf5048;
        --muted: #6c757d;

        /* Colours: light variants. */
        --primary-light: #3a3937;
        --secondary-light: #1a2d42;
        --success-light: #1e3025;
        --warning-light: #3a2e15;
        --danger-light: #3d1f1d;
        --muted-light: #2a2d30;

        /* Colours: active variants. */
        --primary-active: #4a4947;
        --secondary-active: #253d55;
        --success-active: #2a4030;
        --warning-active: #4d3d20;
        --danger-active: #522a27;

        /* Colours: dark variants. */
        --primary-dark: #c0bfbd;
        --secondary-dark: #6db8f7;
        --success-dark: #90d8a5;
        --warning-dark: #f0cc70;
        --danger-dark: #e8807a;
        --muted-dark: #b0b5ba;

        /* Colours: neutral. */
        --white: #1a1a1e;
        --black: #e0e0e0;

        /* Colours: text. */
        --primary-text: #e0dfdd;
        --secondary-text: #6db8f7;
        --success-text: #85cc9a;
        --warning-text: #e0b848;
        --danger-text: #e0756f;
        --muted-text: #9ca3ab;
    }

    /* Checkbox tick: re-drawn using the dark secondary colour.
     * The light-mode SVG fill is hardcoded and will not respond
     * to CSS variables, so a separate rule is required here. */
    input[type="checkbox"]:checked + .checkbox::before {
        background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='1em' height='1em' viewBox='0 0 256 256'%3E%3Cpath fill='%233d9cf0' d='m243.31 90.91l-128.4 128.4a16 16 0 0 1-22.62 0l-71.62-72a16 16 0 0 1 0-22.61l20-20a16 16 0 0 1 22.58 0L104 144.22l96.76-95.57a16 16 0 0 1 22.59 0l19.95 19.54a16 16 0 0 1 .01 22.72'/%3E%3C/svg%3E");
    }

    /* Radio dot: re-drawn using the dark secondary colour. */
    input[type="radio"]:checked + span::before {
        background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='1em' height='1em' viewBox='0 0 256 256'%3E%3Cpath fill='%233d9cf0' d='M232 128A104 104 0 1 1 128 24a104.13 104.13 0 0 1 104 104'/%3E%3C/svg%3E");
    }
}

/* === Accessibility: disable transitions for users who prefer it === */

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        transition-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
    }
}

/* === Page layout === */

html, body {
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font);
    font-size: 100%;
    line-height: var(--line-height);
    color: var(--color-body);
    background-color: var(--main-background);
    min-height: 100vh;
}

.invent-page {
    box-sizing: border-box;
    margin: 1rem auto;
    padding: 2rem;
    width: var(--page-width);
    max-width: var(--page-max-width);
}

/* For apps that need a native app (full width) layout. */
body.app-view .invent-page {
    width: 100%;
    max-width: none;
    margin: 0;
    padding: 1rem;
}

/* === Typography === */

p {
    font-size: 1rem;
}

a {
    color: var(--link);
    text-decoration: none;
}

a:visited {
    color: var(--link-visited);
}

a:hover, a:active {
    color: var(--link-hover);
    text-decoration: underline;
}

a:focus {
    color: var(--link);
    text-decoration: underline;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: bold;
    line-height: 1.2;
}

h1 { font-size: var(--h1-size); }
h2 { font-size: var(--h2-size); }
h3 { font-size: var(--h3-size); }
h4 { font-size: var(--h4-size); }
h5 { font-size: var(--h5-size); }
h6 { font-size: var(--h6-size); }

b, strong {
    font-weight: bolder;
}

code, kbd, samp {
    font-family: var(--font-mono);
    font-size: 1rem;
}

pre {
    display: block;
    max-width: 100%;
    overflow: auto;
    padding: 1rem;
    border: var(--border-width) solid var(--primary-light);
    background-color: var(--muted-light);
}

/* === Tables === */

table {
    border-collapse: collapse;
    width: 100%;
}

tr:nth-child(even) {
    background-color: var(--muted-light);
}

thead {
    background-color: var(--primary-light);
}

th {
    text-align: start;
}

td, th {
    padding: 0.5rem;
}

/* === Multimedia === */

img, video {
    max-width: 100%;
    height: auto;
    object-fit: contain;
}

/* === Form elements === */

input,
select,
textarea {
    color: var(--primary);
    border-color: var(--primary);
    background: transparent;
    border-style: solid;
    border-width: var(--border-width);
    display: block;
    font-size: 1rem;
    /* Suppress the default outline; a keyboard-focus ring is
     * provided via :focus-visible below. */
    outline: none;
    padding: 0.5rem;
}

input:focus,
select:focus,
textarea:focus {
    border-color: var(--secondary);
    border-style: solid;
    border-width: var(--border-width);
}

/* Visible keyboard-focus ring for all interactive elements. */
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
button:focus-visible {
    outline: var(--border-width) solid var(--secondary);
    outline-offset: 2px;
}

select {
    height: 2.35rem;
}

label {
    cursor: pointer;
}

.disabled, input.disabled, input[disabled],
select.disabled, select[disabled],
textarea.disabled, textarea[disabled] {
    cursor: not-allowed;
    opacity: 0.5;
}

/* === Buttons ===
 *
 * The unstyled button has the primary appearance by default.
 * Use .secondary, .success, .warning, or .danger to vary the
 * intent; omit the class (or leave it unstyled) for a primary
 * action.
 */

button {
    align-self: center;
    background-color: var(--primary-light);
    background-image: none;
    border-color: var(--primary);
    border-radius: var(--border-radius-lg);
    border-style: solid;
    border-width: var(--border-width);
    color: var(--primary-text);
    cursor: pointer;
    display: inline-block;
    font-size: 1rem;
    /* Suppress the default outline; a keyboard-focus ring is
     * provided via :focus-visible above. */
    outline: none;
    padding: 0.75rem;
    transition: all var(--transition-speed-button);
}

button:hover {
    background-color: var(--primary-active);
    border-color: var(--primary-dark);
}

button:active {
    background-color: var(--primary);
    border-color: var(--primary-dark);
    color: var(--primary-light);
}

button.large {
    font-size: 2rem;
    padding: 1rem;
}

button.small {
    font-size: 0.75rem;
    padding: 0.5rem;
}

button.secondary {
    color: var(--secondary-text);
    background-color: var(--secondary-light);
    border-color: var(--secondary);
}

button.secondary:hover {
    background-color: var(--secondary-active);
}

button.secondary:active {
    background-color: var(--secondary);
    color: var(--secondary-light);
}

button.success {
    color: var(--success-text);
    background-color: var(--success-light);
    border-color: var(--success);
}

button.success:hover {
    background-color: var(--success-active);
}

button.success:active {
    background-color: var(--success);
    color: var(--success-light);
}

button.warning {
    color: var(--warning-text);
    background-color: var(--warning-light);
    border-color: var(--warning);
}

button.warning:hover {
    background-color: var(--warning-active);
}

button.warning:active {
    background-color: var(--warning);
    color: var(--warning-light);
}

button.danger {
    color: var(--danger-text);
    background-color: var(--danger-light);
    border-color: var(--danger);
}

button.danger:hover {
    background-color: var(--danger-active);
}

button.danger:active {
    background-color: var(--danger);
    color: var(--danger-light);
}

/* === Slider === */

input[type=range] {
    -webkit-appearance: none;
       -moz-appearance: none;
            appearance: none;
    border-width: 0;
    padding: 0;
}

input[type="range"]::-webkit-slider-runnable-track {
    background: var(--secondary);
    border-color: var(--primary);
    border-radius: 18px;
    border-style: solid;
    border-width: 1px;
    cursor: pointer;
    height: 8px;
    margin: 10px 0;
    width: 100%;
}

input[type=range]::-moz-range-track {
    background: var(--secondary);
    border-color: var(--primary);
    border-radius: 18px;
    cursor: pointer;
    height: 8px;
    width: 100%;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
            appearance: none;
    background: var(--white);
    border-color: var(--primary);
    border-radius: 1rem;
    border-style: solid;
    border-width: var(--border-width);
    cursor: pointer;
    height: 36px;
    margin-top: -14px;
    width: 16px;
}

input[type=range]::-moz-range-thumb {
    background: var(--white);
    border-color: var(--primary);
    border-radius: 1rem;
    border-style: solid;
    border-width: var(--border-width);
    cursor: pointer;
    height: 36px;
    width: 16px;
}

input[type=range]::-ms-track {
    background: transparent;
    border-color: transparent;
    border-width: 16px 0;
    color: transparent;
    cursor: pointer;
    height: 8px;
    width: 100%;
}

input[type=range]::-ms-fill-lower,
input[type=range]::-ms-fill-upper {
    background: var(--secondary);
    border-color: var(--primary);
    border-radius: 18px;
    border-style: solid;
    border-width: 1px;
}

input[type=range]::-ms-thumb {
    background: var(--white);
    border-color: var(--primary);
    border-radius: 1rem;
    border-style: solid;
    border-width: var(--border-width);
    cursor: pointer;
    height: 36px;
    width: 16px;
}

/* === Meter === */

meter {
    display: block;
    width: 100%;
    height: 36px;
}

meter::-webkit-meter-optimum-value,
meter::-moz-meter-optimum,
meter::-ms-fill-lower {
    background-color: var(--success);
}

meter::-webkit-meter-suboptimum-value,
meter::-moz-meter-suboptimum,
meter::-ms-fill-middle {
    background-color: var(--warning);
}

meter::-webkit-meter-even-less-good-value,
meter::-moz-meter-sub-suboptimum,
meter::-ms-fill-upper {
    background-color: var(--danger);
}

/* === Progress bar === */

progress:not([value]) {
    accent-color: var(--warning);
    display: block;
    width: 100%;
    height: 18px;
}

progress {
    accent-color: var(--secondary);
    display: block;
    width: 100%;
    height: 18px;
}

/* === Checkboxes, switches, and radio buttons === */

input[type="checkbox"], input[type="radio"] {
    border: 0;
    height: 1px;
    margin: -1px;
    opacity: 0;
    overflow: hidden;
    padding: 0;
    position: absolute;
    width: 1px;
}

input[type="checkbox"] + span,
input[type="radio"] + span {
    cursor: pointer;
    display: inline-block;
    font-size: 1rem;
    margin: 15px 0;
    position: relative;
}

/* Checkbox tick SVG: fill matches the light secondary colour.
 * The dark-theme override is in the dark @media block above. */
input[type="checkbox"]:checked + .checkbox::before {
    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='1em' height='1em' viewBox='0 0 256 256'%3E%3Cpath fill='%230b74d5' d='m243.31 90.91l-128.4 128.4a16 16 0 0 1-22.62 0l-71.62-72a16 16 0 0 1 0-22.61l20-20a16 16 0 0 1 22.58 0L104 144.22l96.76-95.57a16 16 0 0 1 22.59 0l19.95 19.54a16 16 0 0 1 .01 22.72'/%3E%3C/svg%3E");
}

input[type="checkbox"] + .checkbox::before {
    border-color: var(--primary);
    border-style: solid;
    border-width: var(--border-width);
    border-radius: var(--border-radius);
    content: "";
    display: inline-block;
    height: 1rem;
    margin-right: 0.75em;
    position: relative;
    vertical-align: -0.25em;
    width: 1rem;
}

input[type="radio"] + span {
    padding: 0 15px;
}

/* Radio dot SVG: fill matches the light secondary colour.
 * The dark-theme override is in the dark @media block above. */
input[type="radio"]:checked + span::before {
    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='1em' height='1em' viewBox='0 0 256 256'%3E%3Cpath fill='%230b74d5' d='M232 128A104 104 0 1 1 128 24a104.13 104.13 0 0 1 104 104'/%3E%3C/svg%3E");
}

input[type="radio"] + span::before {
    border-color: var(--primary);
    border-style: solid;
    border-width: var(--border-width);
    border-radius: 50%;
    content: "";
    display: inline-block;
    height: 1rem;
    margin-right: 0.75em;
    position: relative;
    vertical-align: -0.25em;
    width: 1rem;
}

/* Switch. */

.switch {
    display: inline-block;
    height: 1.5rem;
    margin-right: 0.75em;
    position: relative;
    width: 3rem;
}

.switch-label {
    cursor: pointer;
    padding-top: 0.25em;
    position: absolute;
}

.slider {
    background-color: var(--primary-light);
    border: var(--border-width) solid var(--primary);
    border-radius: var(--border-radius);
    bottom: 0;
    cursor: pointer;
    height: 1.5rem;
    left: 0;
    margin: 0 1rem 0 0 !important;
    position: absolute;
    right: 0;
    top: 0;
    transition: var(--transition-speed);
    width: 3rem;
}

.slider:before {
    background-color: var(--white);
    bottom: 4px;
    content: "";
    height: 1rem;
    left: 4px;
    position: absolute;
    transition: var(--transition-speed);
    width: 1rem;
}

input[type="checkbox"]:focus + .slider {
    box-shadow: 0 0 1px var(--secondary);
}

input[type="checkbox"]:checked + .slider {
    background-color: var(--secondary) !important;
}

input[type="checkbox"]:checked + .slider:before {
    transform: translateX(1.5rem);
}

/* === Audio === */

audio {
    display: block;
    margin: 0 auto;
    width: 100%;
}

/* === Specialised text inputs === */

input[type="email"] {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='1em' height='1em' viewBox='0 0 256 256'%3E%3Cpath fill='grey' d='M224 48H32a8 8 0 0 0-8 8v136a16 16 0 0 0 16 16h176a16 16 0 0 0 16-16V56a8 8 0 0 0-8-8m-96 85.15L52.57 64h150.86ZM98.71 128L40 181.81V74.19Zm11.84 10.85l12 11.05a8 8 0 0 0 10.82 0l12-11.05l58 53.15H52.57ZM157.29 128L216 74.18v107.64Z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right;
    background-size: contain;
}

input[type="password"] {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='1em' height='1em' viewBox='0 0 256 256'%3E%3Cpath fill='grey' d='M48 56v144a8 8 0 0 1-16 0V56a8 8 0 0 1 16 0m92 54.5l-20 6.5V96a8 8 0 0 0-16 0v21l-20-6.5a8 8 0 0 0-5 15.22l20 6.49l-12.34 17a8 8 0 1 0 12.94 9.4l12.34-17l12.34 17a8 8 0 1 0 12.94-9.4l-12.34-17l20-6.49A8 8 0 0 0 140 110.5m106 5.14a8 8 0 0 0-10-5.14l-20 6.5V96a8 8 0 0 0-16 0v21l-20-6.49a8 8 0 0 0-4.95 15.22l20 6.49l-12.34 17a8 8 0 1 0 12.94 9.4l12.34-17l12.34 17a8 8 0 1 0 12.94-9.4l-12.34-17l20-6.49a8 8 0 0 0 5.07-10.09'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right;
    background-size: contain;
}

input[type="tel"] {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='1em' height='1em' viewBox='0 0 256 256'%3E%3Cpath fill='grey' d='m222.37 158.46l-47.11-21.11l-.13-.06a16 16 0 0 0-15.17 1.4a8 8 0 0 0-.75.56L134.87 160c-15.42-7.49-31.34-23.29-38.83-38.51l20.78-24.71c.2-.25.39-.5.57-.77a16 16 0 0 0 1.32-15.06v-.12L97.54 33.64a16 16 0 0 0-16.62-9.52A56.26 56.26 0 0 0 32 80c0 79.4 64.6 144 144 144a56.26 56.26 0 0 0 55.88-48.92a16 16 0 0 0-9.51-16.62M176 208A128.14 128.14 0 0 1 48 80a40.2 40.2 0 0 1 34.87-40a.6.6 0 0 0 0 .12l21 47l-20.67 24.74a6 6 0 0 0-.57.77a16 16 0 0 0-1 15.7c9.06 18.53 27.73 37.06 46.46 46.11a16 16 0 0 0 15.75-1.14a8 8 0 0 0 .74-.56L168.89 152l47 21.05h.11A40.21 40.21 0 0 1 176 208'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right;
    background-size: contain;
}

input[type="url"] {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='1em' height='1em' viewBox='0 0 256 256'%3E%3Cpath fill='grey' d='M128 24a104 104 0 1 0 104 104A104.12 104.12 0 0 0 128 24m88 104a87.6 87.6 0 0 1-3.33 24h-38.51a157.4 157.4 0 0 0 0-48h38.51a87.6 87.6 0 0 1 3.33 24m-114 40h52a115.1 115.1 0 0 1-26 45a115.3 115.3 0 0 1-26-45m-3.9-16a140.8 140.8 0 0 1 0-48h59.88a140.8 140.8 0 0 1 0 48ZM40 128a87.6 87.6 0 0 1 3.33-24h38.51a157.4 157.4 0 0 0 0 48H43.33A87.6 87.6 0 0 1 40 128m114-40h-52a115.1 115.1 0 0 1 26-45a115.3 115.3 0 0 1 26 45m52.33 0h-35.62a135.3 135.3 0 0 0-22.3-45.6A88.29 88.29 0 0 1 206.37 88Zm-98.74-45.6A135.3 135.3 0 0 0 85.29 88H49.63a88.29 88.29 0 0 1 57.96-45.6M49.63 168h35.66a135.3 135.3 0 0 0 22.3 45.6A88.29 88.29 0 0 1 49.63 168m98.78 45.6a135.3 135.3 0 0 0 22.3-45.6h35.66a88.29 88.29 0 0 1-57.96 45.6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right;
    background-size: contain;
}

/* === Colour picker === */

input[type="color"] {
    border: var(--border-width) solid var(--primary);
    border-radius: var(--border-radius);
    cursor: pointer;
    display: inline-block;
    height: 2rem;
    margin-right: 0.75em;
    padding: 0.1rem;
    width: 3rem;
}

/* === File selector === */

input[type="file"] {
    border: 0;
    cursor: pointer;
}

/* === Date and time pickers === */

input[type="date"],
input[type="time"],
input[type="datetime-local"] {
    border: var(--border-width) solid var(--primary);
    cursor: pointer;
    display: inline-block;
    margin-right: 0.75em;
}

/* === Accordion === */

.accordion-item {
    border: var(--border-width) solid var(--primary);
    display: grid;
    grid-template-rows: max-content 0fr;
    isolation: isolate;
    overflow: hidden;
    padding-bottom: 8px;
    position: relative;
    transition: grid-template-rows var(--transition-speed);

    > input:is([type="checkbox"], [type="radio"]) {
        appearance: none;
        grid-column-start: 1;
        grid-row-start: 1;
        opacity: 0;
    }

    &:is([open], :focus:not(.collapse-close)),
    &:not(.collapse-close):has(
        > input:is([type="checkbox"], [type="radio"]):checked
    ) {
        grid-template-rows: max-content 1fr;
    }

    &:is([open], :focus:not(.collapse-close)) > .collapse-content,
    &:not(.collapse-close) > :where(
        input:is([type="checkbox"],
        [type="radio"]):checked ~ .collapse-content
    ) {
        min-height: fit-content;
        visibility: visible;
    }

    &:focus-visible,
    &:has(
        > input:is([type="checkbox"], [type="radio"]):focus-visible
    ) {
        outline-color: var(--color-body);
        outline-offset: 2px;
        outline-style: solid;
        outline-width: var(--border-width);
    }

    &:not(.collapse-close) {
        > input[type="checkbox"],
        > input[type="radio"]:not(:checked),
        > .collapse-title {
            cursor: pointer;
        }
    }

    &:focus:not(.collapse-close, .collapse[open]) > .collapse-title {
        cursor: unset;
    }

    &:is([open], :focus:not(.collapse-close)) > :where(.collapse-content),
    &:not(.collapse-close) > :where(
        input:is([type="checkbox"],
        [type="radio"]):checked ~ .collapse-content
    ) {
        padding-bottom: 1rem;
        transition:
            padding var(--transition-speed) ease-out,
            background-color var(--transition-speed) ease-out;
    }

    > input:is([type="checkbox"], [type="radio"]) {
        min-height: 1lh;
        padding: 1rem;
        padding-inline-end: 3rem;
        transition: background-color var(--transition-speed) ease-out;
        width: 100%;
        z-index: 1;
    }

    /* Rotate the chevron when the accordion is open. */
    &:is([open]) > .accordion-title:after,
    &.collapse-open > .accordion-title:after,
    &:focus:not(.collapse-close) > .accordion-title:after,
    &:not(.collapse-close) > input:is(
        [type="checkbox"], [type="radio"]
    ):checked ~ .accordion-title:after {
        transform: translateY(-50%) rotate(225deg);
    }

    > .accordion-title:after {
        content: "";
        display: inline-block;
        height: 0.5rem;
        width: 0.5rem;
        border-inline-end: var(--border-width) solid currentColor;
        border-block-end: var(--border-width) solid currentColor;
        transform: translateY(-100%) rotate(45deg);
        transform-origin: 75% 75%;
        transition-property: all;
        transition-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
        transition-duration: var(--transition-speed);
        inset-inline-end: 1.4rem;
        pointer-events: none;
        position: absolute;
        top: 1.9rem;
    }
}

.accordion-title,
.accordion-content {
    grid-column-start: 1;
    grid-row-start: 1;
}

.accordion-title {
    font-weight: bold;
    padding: 1rem;
}

.accordion-content {
    box-sizing: border-box;
    cursor: unset;
    grid-row-start: 2;
    max-width: 100%;
    min-height: 0;
    overflow-x: auto;
    padding-left: 1rem;
    padding-right: 1rem;
    transition:
        visibility var(--transition-speed),
        padding var(--transition-speed) ease-out,
        background-color var(--transition-speed) ease-out;
    visibility: hidden;
    word-break: break-word;
}

/* === Tabs === */

.invent-tabs {
    border-radius: var(--border-radius) var(--border-radius) 0 0;
    box-sizing: border-box;
    display: flex;
    flex-wrap: wrap;
    margin: 0 auto 20px;
    width: 100%;
}

.invent-tabs-radiotab {
    opacity: 0;
    position: absolute;
}

.invent-tabs-label {
    background-color: var(--primary-light);
    border: solid var(--border-width) var(--primary);
    cursor: pointer;
    font-weight: bold;
    padding: 22px 20px;
    width: 100%;
}

.invent-tabs-panel {
    background: var(--main-background);
    border-bottom: solid var(--border-width) var(--primary);
    border-left: solid var(--border-width) var(--primary);
    border-right: solid var(--border-width) var(--primary);
    box-sizing: border-box;
    display: none;
    max-width: 100%;
    overflow-x: auto;
    padding: 20px 30px 30px;
    width: 100%;
    word-break: break-word;
}

.invent-tabs-radiotab:checked + .invent-tabs-label {
    background: var(--main-background);
    border-bottom: none;
    border-right: solid var(--border-width) var(--primary);
    border-top: solid var(--border-width) var(--primary);
}

.invent-tabs-radiotab:checked + .invent-tabs-label + .invent-tabs-panel {
    display: block;
}

/* Tabs: wider-screen layout (breakpoint: 600px). */
@media (min-width: 600px) {
    .invent-tabs-panel {
        order: 99;
    }

    .invent-tabs-label {
        border-bottom: solid var(--border-width) var(--primary);
        border-left: none;
        border-radius:
            var(--border-radius-lg) var(--border-radius-lg) 0 0;
        flex-grow: 1;
        min-width: calc(100% / 8);
        width: unset;
    }

    :nth-child(1 of label.invent-tabs-label) {
        border-left: solid var(--border-width) var(--primary);
    }
}

/* -- Tree view widget, uses native <details>/<summary> -- */
/* -- for toggling with no JavaScript required.         -- */
.invent-tree {
    font-family: var(--font);
    color: var(--color-body);
    background: var(--main-background);
    padding: 0.25rem 0;
    user-select: none;
}

/* -- Nested branches and leaves indented under their parent. -- */
.invent-tree details details,
.invent-tree details .invent-tree-leaf {
    margin-inline-start: 1.5rem;
}

/* -- Remove the default browser disclosure triangle. -- */
.invent-tree summary {
    list-style: none;
    cursor: pointer;
    padding: 0.3rem 0.5rem;
    border-radius: 3px;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-weight: 600;
    color: var(--primary-text);
    transition: background 0.15s ease;
}

.invent-tree summary::marker,
.invent-tree summary::-webkit-details-marker {
    display: none;
}

/* -- Toggle arrow sits before the label. -- */
.invent-tree summary::before {
    content: "▶";
    font-size: 0.65rem;
    color: var(--secondary);
    transition: transform 0.15s ease;
    display: inline-block;
    flex-shrink: 0;
}

.invent-tree details[open] > summary::before {
    transform: rotate(90deg);
}

/* -- Leaf wrapper: flex row to align bullet with content. -- */
.invent-tree-leaf {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.15rem 0.5rem;
    border-radius: 3px;
    transition: background 0.15s ease;
}

/* -- Muted bullet aligns leaves with sibling branch labels. -- */
.invent-tree-leaf::before {
    content: "•";
    font-size: 1.6rem;
    color: var(--muted);
    flex-shrink: 0;
}

/* -- Hover and focus states. -- */
.invent-tree summary:hover {
    background: var(--primary-light);
}

.invent-tree summary:focus-visible {
    outline: 2px solid var(--secondary);
    outline-offset: -2px;
}

.invent-tree summary:active {
    background: var(--primary-active);
}

.invent-tree-leaf:hover {
    background: var(--secondary-light);
}

/* === Header and Footer containers === */

/* -- Shared base: a tinted background distinguishes         -- */
/* -- header/footer from the main page body whilst keeping  -- */
/* -- all child widget colours intact.                      -- */
.invent-header,
.invent-footer {
    display: flex;
    flex-flow: row wrap;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    width: 100%;
    box-sizing: border-box;
    background: var(--primary-light);
    color: var(--color-body);
    font-family: var(--font);
    /* -- Subtle shadow lifts the bars off the page content. -- */
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
    transition: box-shadow var(--transition-speed) ease;
}

/* -- Accent stripe on the inward-facing edge of each bar.  -- */
.invent-header {
    border-block-end: 3px solid var(--secondary);
}

.invent-footer {
    border-block-start: 3px solid var(--secondary);
}

/* -- Sticky header: pins to top; stronger shadow signals    -- */
/* -- it is floating above scrolled content.               -- */
.invent-header--sticky {
    position: sticky;
    top: 0;
    z-index: 99999;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.18);
}

/* -- Sticky footer: pins to bottom; shadow points upward.  -- */
.invent-footer--sticky {
    position: sticky;
    bottom: 0;
    z-index: 99999;
    box-shadow: 0 -3px 10px rgba(0, 0, 0, 0.18);
}

/* -- Dark mode: a slightly lifted tone distinguishes the    -- */
/* -- bars from the darker page body.                       -- */
@media (prefers-color-scheme: dark) {
    .invent-header,
    .invent-footer {
        background: var(--muted-dark);
        color: var(--white);
        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.35);
    }

    .invent-header--sticky,
    .invent-footer--sticky {
        box-shadow: 0 3px 12px rgba(0, 0, 0, 0.5);
    }
}

/* -- Reduced motion: disable shadow transitions. -- */
@media (prefers-reduced-motion: reduce) {
    .invent-header,
    .invent-footer {
        transition: none;
    }
}

/* === Calendar widget ===
 *
 * Scoped under .invent-calendar to avoid conflicts with the base
 * table styles in theme.css (especially zebra-striping and thead
 * background, which do not suit a calendar layout).
 *
 * Depends on the CSS variables defined in theme.css.
 */

/* -- Outer wrapper: contains nav bar and table. -- */
.invent-calendar {
    border: var(--border-width) solid var(--primary-light);
    border-radius: var(--border-radius-lg);
    font-family: var(--font);
    /* Clip the table so rounded corners apply cleanly. */
    overflow: hidden;
}

/* -- Navigation bar: previous/next buttons with centred title. -- */
.invent-calendar-nav {
    align-items: center;
    background: var(--primary-light);
    border-block-end: var(--border-width) solid var(--primary-light);
    display: flex;
    justify-content: space-between;
    padding: 0.4rem 0.6rem;
}

.invent-calendar-nav h2 {
    flex: 1;
    font-size: 1.1rem;
    font-weight: bold;
    margin: 0;
    text-align: center;
}

/* -- Nav buttons: compact variant of the base button style. -- */
.invent-calendar-nav button {
    border-radius: var(--border-radius);
    font-size: 1.5rem;
    line-height: 1;
    padding: 0.1rem 0.5rem;
}

/* -- Base table overrides for the calendar context. -- */

/* Suppress the base zebra-striping inside the calendar. */
.invent-calendar tr:nth-child(even) {
    background-color: transparent;
}

/* Suppress the default thead background; the nav bar serves
 * as the visual header for the widget. */
.invent-calendar thead {
    background-color: var(--muted-light);
}

.invent-calendar table {
    border-collapse: collapse;
    table-layout: fixed;
    width: 100%;
}

/* -- Day-name column headers. -- */
.invent-calendar th {
    border-block-end: var(--border-width) solid var(--primary-light);
    color: var(--muted-text);
    font-size: 0.8rem;
    font-weight: bold;
    padding: 0.35rem 0;
    text-align: center;
}

/* Weekend column headers: slightly de-emphasised. */
.invent-calendar th:nth-child(6),
.invent-calendar th:nth-child(7) {
    color: var(--primary-light);
    background-color: var(--primary-light);
    color: var(--primary);
}

/* -- All cells: shared baseline. -- */
.invent-calendar td {
    border: 1px solid var(--primary-light);
    padding: 0;
    vertical-align: top;
    width: calc(100% / 7);
}

/* -- Inner wrapper: fixed height with scroll for overflow content. -- */
.invent-calendar td > div {
    box-sizing: border-box;
    height: 8rem;
    overflow-y: auto;
    padding: 0.3rem 0.35rem;
    /* Firefox scrollbar: thin width with theme colours. */
    scrollbar-width: thin;
    scrollbar-color: var(--secondary) var(--primary-light);
}

/* WebKit scrollbar (Chrome, Safari, Edge): width and theme colours. */
.invent-calendar td > div::-webkit-scrollbar {
    width: var(--border-width);
}

.invent-calendar td > div::-webkit-scrollbar-track {
    background: var(--primary-light);
}

.invent-calendar td > div::-webkit-scrollbar-thumb {
    background: var(--secondary);
}

/* -- Padding cells: days outside the current month. -- */
.invent-calendar td.calendar-empty {
    background: var(--muted-light);
}

/* -- Active day cells. -- */
.invent-calendar td.calendar-day {
    background: var(--main-background);
}

/* -- Today: accent stripe on the top edge. -- */
.invent-calendar td.calendar-today {
    background: var(--warning-light);
    border-block-start: 3px solid var(--warning);
}

/* -- Day number: displayed top-right within each cell. -- */
.invent-calendar .calendar-day-num {
    color: var(--muted-text);
    display: block;
    font-size: 0.8rem;
    font-weight: bold;
    line-height: 1;
    margin-block-end: 0.25rem;
    text-align: end;
}

/* Today's number gets the warning accent colour. */
.invent-calendar td.calendar-today .calendar-day-num {
    color: var(--warning);
}

/* -- Events list: stacked chips below the day number. -- */
.invent-calendar .calendar-events {
    display: flex;
    flex-direction: column;
    gap: 0.15rem;
    list-style: none;
    margin: 0;
    padding: 0;
}

.invent-calendar .calendar-events li {
    background: var(--secondary-light);
    border-inline-start: 2px solid var(--secondary);
    border-radius: 2px;
    color: var(--primary-text);
    font-size: 0.7rem;
    line-height: 1.3;
    overflow: hidden;
    padding: 0.1rem 0.25rem;
    word-break: break-word;
}

/* Event time: monospaced and in the secondary text colour. */
.invent-calendar .calendar-events time {
    color: var(--secondary-text);
    font-family: var(--font-mono);
    font-size: 0.65rem;
    margin-inline-end: 0.2rem;
}

/* -- Dark mode adjustments. -- */
@media (prefers-color-scheme: dark) {
    .invent-calendar td.calendar-today {
        background: var(--warning-light);
    }

    .invent-calendar .calendar-events li {
        background: var(--secondary-light);
    }
}

/* -- Responsive: compact layout for narrow viewports.
 *    Breakpoint: 600px (matches --breakpoint-sm in theme.css). -- */
@media (max-width: 599px) {
    .invent-calendar td > div {
        height: 2.8rem;
        padding: 0.2rem 0.15rem;
    }

    /* Hide event chips; a dot signals the presence of events. */
    .invent-calendar .calendar-events {
        display: none;
    }

    /* Small coloured dot below the day number for cells with events. */
    .invent-calendar td.has-events::after {
        background: var(--secondary);
        border-radius: 50%;
        content: "";
        display: block;
        height: 0.35rem;
        margin: 0.15rem auto 0;
        width: 0.35rem;
    }

    .invent-calendar .calendar-day-num {
        font-size: 0.7rem;
        text-align: center;
    }

    .invent-calendar th {
        font-size: 0.6rem;
        padding: 0.25rem 0;
    }

    .invent-calendar-nav h2 {
        font-size: 0.95rem;
    }

    .invent-calendar-nav button {
        font-size: 1.2rem;
        padding: 0.1rem 0.35rem;
    }
}

/* --- Bubble-local variables -------------------------------------------- */

/* These are per-instance overrides, not theme-level tokens.
 * --bubble-bg is set inline per participant; it falls back to
 * the theme's secondary colour as a sensible default.
 * --bubble-text is the text colour rendered over --bubble-bg;
 * override inline if a dark bubble colour needs light text. */
.invent-bubble {
    --bubble-bg:   var(--secondary);
    --bubble-text: var(--white);
    --bubble-link: var(--secondary-light);
    /* Size of the triangular tail pointing toward the avatar. */
    --bubble-tail: 0.5rem;
    --avatar-size: 2.5rem;
    --bubble-gap:  0.6rem;
    --max-width:   70%;
}

.invent-bubble.sent {
    --bubble-bg: var(--primary);
}

/* --- Bubble container -------------------------------------------------- */

/* Row holding the optional avatar and the bubble body side by side. */
.invent-bubble {
    display:        flex;
    align-items:    flex-end;
    gap:            var(--bubble-gap);
    max-width:      var(--max-width);
    /* Default: received message sits on the left. */
    flex-direction: row;
}

/* Sent bubbles sit on the right edge of the container. */
.invent-bubble.sent {
    flex-direction: row-reverse;
    align-self:     flex-end;
}

.invent-bubble-body a {
    color: var(--bubble-link, var(--link));
    text-decoration: underline;
}

.invent-bubble-body a:hover {
    color: var(--bubble-link, var(--link-hover));
    opacity: 0.85;
}

/* RTL locales: mirror sent/received so layout follows reading order. */
[dir="rtl"] .invent-bubble          { flex-direction: row-reverse; }
[dir="rtl"] .invent-bubble.sent     { flex-direction: row; }

/* --- Avatar ------------------------------------------------------------ */

/* The avatar image sits outside the bubble, beside the tail. */
.invent-bubble > img {
    width:         var(--avatar-size);
    height:        var(--avatar-size);
    border-radius: 50%;
    flex-shrink:   0;
    object-fit:    cover;
    box-shadow:    0 1px 3px rgba(0, 0, 0, 0.15);
}

/* --- Bubble body ------------------------------------------------------- */

/* The coloured bubble containing all message content. */
.invent-bubble-body {
    position:      relative;
    background:    var(--bubble-bg);
    color:         var(--bubble-text);
    border-radius: var(--border-radius-lg);
    padding:       0.6rem 0.85rem;
    box-shadow:    0 2px 6px rgba(0, 0, 0, 0.1);
}

/* --- Bubble tail ------------------------------------------------------- */

/* Tail for received bubbles: points left toward the avatar side. */
.invent-bubble.received .invent-bubble-body::after {
    content:      '';
    position:     absolute;
    bottom:       0.6rem;
    left:         calc(-1 * var(--bubble-tail));
    border-width: var(--bubble-tail) var(--bubble-tail) 0 0;
    border-style: solid;
    /* Only the right border is visible, inheriting the bubble colour. */
    border-color:
        transparent
        var(--bubble-bg)
        transparent
        transparent;
}

/* Tail for sent bubbles: points right toward the avatar side. */
.invent-bubble.sent .invent-bubble-body::after {
    content:      '';
    position:     absolute;
    bottom:       0.6rem;
    right:        calc(-1 * var(--bubble-tail));
    border-width: var(--bubble-tail) 0 0 var(--bubble-tail);
    border-style: solid;
    /* Only the left border is visible, inheriting the bubble colour. */
    border-color:
        transparent
        transparent
        transparent
        var(--bubble-bg);
}

/* --- Metadata: username ------------------------------------------------ */

.invent-bubble-body header {
    margin-bottom: 0.3rem;
}

.invent-bubble-body header strong {
    font-size:   0.75rem;
    font-weight: 600;
    opacity:     0.85;
}

/* --- Message text ------------------------------------------------------ */

.invent-bubble-body p {
    line-height: var(--line-height);
}

/* --- Metadata: timestamp ----------------------------------------------- */

.invent-bubble-body footer {
    margin-top: 0.35rem;
    text-align: end;
}

/* Semi-transparent so it reads as secondary information over any
 * bubble colour without needing a per-colour text override. */
.invent-bubble-body footer time {
    font-size: 0.7rem;
    color: var(--bubble-text);
    opacity: 0.75;
}

/* --- Responsive: narrow screens (breakpoint: 600px) ------------------- */

@media (max-width: 599px) {
    .invent-bubble {
        --max-width: 85%;
    }
}


/* === ContentCard widget ==============================================
 *
 * A card for displaying a title, optional image/icon, optional
 * timestamp and a body of rendered content.
 *
 * Modifier classes on the root <article>:
 *   .square       — removes rounded corners.
 *   .banner-image — renders the image as a full-width banner above
 *                   the header rather than as a circular avatar.
 *   .publish-end  — moves the timestamp from the header to the footer.
 *
 * Structural visibility is data-driven: Python sets or clears
 * attribute values (src, datetime) and textContent; CSS rules here
 * hide any element that carries no data.  The DOM skeleton is always
 * fully present; nothing is ever added or removed by Python.
 *
 * Works well inside an .invent-timeline column container.
 */

/* --- Local variables -------------------------------------------------- */

/* Per-instance overrides: re-declare inline on .invent-card to
 * customise background, border colour, and shape for one card. */
.invent-card {
    --card-bg:           var(--main-background);
    --card-border-color: var(--primary-light);
    --card-radius:       var(--border-radius-lg);
    --card-avatar-size:  2.5rem;
    --card-padding:      1rem;
}

/* --- Structural visibility rules -------------------------------------- */

/* Elements carrying no data are hidden so that Python change handlers
 * need only update attribute values, never add or remove nodes. */

/* Images with no src set are invisible. */
.invent-card img[src=""] {
    display: none;
}

/* An empty heading occupies no space. */
.invent-card header h3:empty {
    display: none;
}

/* Timestamps with no datetime value are invisible. */
.invent-card time[datetime=""] {
    display: none;
}

/* --- Card container --------------------------------------------------- */

/* Self-contained block with border, shadow and flexible column layout. */
.invent-card {
    background:     var(--card-bg);
    border:         var(--border-width) solid var(--card-border-color);
    border-radius:  var(--card-radius);
    box-shadow:     0 2px 6px rgba(0, 0, 0, 0.08);
    box-sizing:     border-box;
    display:        flex;
    flex-direction: column;
    /* Required to clip the banner image to the card's rounded corners. */
    overflow:       hidden;
    padding:        var(--card-padding);
    width:          100%;
}

/* Square variant: suppress all corner rounding. */
.invent-card.square {
    --card-radius: 0;
}

/* --- Banner image ----------------------------------------------------- */

/* Hidden by default; shown only when the card is in banner-image mode
 * and the src attribute has been set. */
.invent-card > img {
    display: none;
}

/* Full-width image spanning the card edges above the header.
 * Negative margins pull the image outside the card's padding box;
 * overflow: hidden on the card clips it to the rounded corners. */
.invent-card.banner-image > img:not([src=""]) {
    display:       block;
    height:        12rem;
    margin:        calc(-1 * var(--card-padding));
    margin-bottom: var(--card-padding);
    max-width:     none;
    object-fit:    cover;
    width:         calc(100% + 2 * var(--card-padding));
}

/* Avatar hidden when the banner-image mode is active. */
.invent-card.banner-image header > img {
    display: none;
}

/* --- Header ----------------------------------------------------------- */

/* Flex row: optional avatar on the start side, metadata on the other. */
.invent-card header {
    align-items:   center;
    display:       flex;
    gap:           0.75rem;
    margin-bottom: 0.75rem;
}

/* Avatar image: circular, fixed size, does not shrink. */
.invent-card header > img {
    border-radius: 50%;
    flex-shrink:   0;
    height:        var(--card-avatar-size);
    object-fit:    cover;
    width:         var(--card-avatar-size);
}

/* Metadata group: title and optional timestamp stacked vertically.
 * min-width: 0 prevents long titles from overflowing the flex row. */
.invent-card header > div {
    display:        flex;
    flex-direction: column;
    gap:            0.15rem;
    min-width:      0;
}

/* Card title: overrides the global h3 size which is too large here. */
.invent-card header h3 {
    font-size:   1rem;
    font-weight: 600;
    line-height: 1.3;
    margin:      0;
}

/* Timestamp inside the header: muted, monospaced, small. */
.invent-card header time {
    color:       var(--muted-text);
    font-family: var(--font-mono);
    font-size:   0.7rem;
    line-height: 1;
}

/* Header timestamp hidden when the card is in publish-end mode. */
.invent-card.publish-end header time {
    display: none;
}

/* --- Body ------------------------------------------------------------- */

/* Container for widget children; grows to fill remaining card height. */
.invent-card > div {
    flex:        1;
    font-size:   0.95rem;
    line-height: var(--line-height);
    min-width:   0;
}

/* Remove surplus spacing at the top and bottom of the body content. */
.invent-card > div > :first-child { margin-top:    0; }
.invent-card > div > :last-child  { margin-bottom: 0; }

/* --- Footer ----------------------------------------------------------- */

/* Hidden by default; only shown as an end-position timestamp. */
.invent-card footer {
    display:         none;
    border-top:      var(--border-width) solid var(--card-border-color);
    justify-content: flex-end;
    margin-top:      0.75rem;
    padding-top:     0.5rem;
}

/* Footer shown when publish-end mode is active. */
.invent-card.publish-end footer {
    display: flex;
}

/* Footer hidden again if the timestamp carries no datetime value. */
.invent-card.publish-end footer:has(time[datetime=""]) {
    display: none;
}

/* Timestamp inside the footer: same style as the header timestamp. */
.invent-card footer time {
    color:       var(--muted-text);
    font-family: var(--font-mono);
    font-size:   0.7rem;
}

/* --- RTL support ------------------------------------------------------ */

/* Flex and logical margin properties handle most of the mirroring
 * automatically; the avatar and banner images need no special rules. */

/* --- Responsive: narrow screens (breakpoint: 600px) ------------------- */

@media (max-width: 599px) {
    .invent-card {
        --card-padding:     0.75rem;
        --card-avatar-size: 2rem;
    }

    /* Reduce the banner height on small screens. */
    .invent-card.banner-image > img:not([src=""]) {
        height: 8rem;
    }
}

/* Avatar widget. A circular, rounded, or square image representing
 * a person or entity. Sizes follow the Invent t-shirt scale. */

/* --- Size tokens ---------------------------------------------------------- */

:root {
    --avatar-size-xs:  1.5rem;
    --avatar-size-s:   2rem;
    --avatar-size-m:   3rem;
    --avatar-size-l:   4.5rem;
    --avatar-size-xl:  6rem;
}

/* --- Base widget ---------------------------------------------------------- */

figure.invent-avatar {
    /* Inline-flex keeps the figure tight around the image. */
    display:        inline-flex;
    margin:         0;
    padding:        0;
    cursor:         pointer;
    /* Default size. */
    width:          var(--avatar-size-medium);
    height:         var(--avatar-size-medium);
}

figure.invent-avatar img {
    width:          100%;
    height:         100%;
    object-fit:     cover;
    /* Inherit border-radius from the figure so one class controls
     * the shape for both the container and the image. */
    border-radius:  inherit;
    display:        block;
}

/* --- Shape modifiers ------------------------------------------------------ */

/* Fully circular avatar. */
figure.invent-avatar.invent-avatar--circle {
    border-radius: 50%;
}

/* Softly rounded corners. */
figure.invent-avatar.invent-avatar--rounded {
    border-radius: var(--border-radius);
}

/* No rounding: hard square corners. */
figure.invent-avatar.invent-avatar--square {
    border-radius: 0;
}

/* --- Size modifiers ------------------------------------------------------- */

figure.invent-avatar.invent-avatar--xs {
    width:  var(--avatar-size-xs);
    height: var(--avatar-size-xs);
}

figure.invent-avatar.invent-avatar--s {
    width:  var(--avatar-size-s);
    height: var(--avatar-size-s);
}

figure.invent-avatar.invent-avatar--m {
    width:  var(--avatar-size-m);
    height: var(--avatar-size-m);
}

figure.invent-avatar.invent-avatar--l {
    width:  var(--avatar-size-l);
    height: var(--avatar-size-l);
}

figure.invent-avatar.invent-avatar--xl {
    width:  var(--avatar-size-xl);
    height: var(--avatar-size-xl);
}

/* --- Focus / keyboard accessibility -------------------------------------- */

/* Visible focus ring for keyboard navigation. */
figure.invent-avatar:focus-visible {
    outline:        3px solid var(--primary);
    outline-offset: 2px;
}

/* --- Responsive ----------------------------------------------------------- */

/* On very narrow screens shrink large avatars so they don't overflow. */
@media (max-width: 600px) {
    figure.invent-avatar.invent-avatar--xl {
        width:  var(--avatar-size-l);
        height: var(--avatar-size-l);
    }
}

/* Alert widget.
 *
 * Python sets --alert-bg and --alert-border-color inline via
 * on_purpose_changed(). The defaults here cover the DEFAULT purpose.
 * Hidden until text is set; on_text_changed() drives display. */
.invent-alert {
    --alert-bg:           var(--main-background);
    --alert-border-color: var(--primary-light);

    display:       none;
    position:      relative;
    padding:       var(--card-padding, 1rem);
    border:        var(--border-width) solid var(--alert-border-color);
    border-radius: var(--border-radius-lg);
    background:    var(--alert-bg);
    color:         var(--color-body);
    box-sizing:    border-box;
}

/* Title: block paragraph above the body text. */
.invent-alert p.alert-title {
    font-weight:   600;
    margin-bottom: 0.35rem;
    margin-top:    0;
    padding-inline-end: 2rem;
}

/* Empty title occupies no space. */
.invent-alert p.alert-title:empty {
    display: none;
}

/* Dismiss button: larger and bolder for visibility. */
.invent-alert button {
    position:         absolute;
    top:              0.5rem;
    inset-inline-end: 0.5rem;
    background:       none;
    border:           none;
    cursor:           pointer;
    color:            inherit;
    font-size:        var(--h6-size);
    font-weight:      600;
    line-height:      1;
    opacity:          0.6;
}

.invent-alert button:hover {
    opacity: 1;
}

/* Modal widget.
 *
 * A full-viewport backdrop with a centred dialog box floating above it.
 * The trigger button lives in the normal page flow; the backdrop and box
 * are appended to <body> at open time and removed on dismissal.
 * Clicking outside the box (i.e. on the backdrop itself) also dismisses
 * the modal. */

/* --- Design tokens --------------------------------------------------- */

:root {
    --modal-max-width:      560px;
    --modal-padding:        1.5rem;
    /* Semi-transparent dark veil behind the dialog box. */
    --modal-backdrop-color: rgba(0, 0, 0, 0.45);
    --modal-backdrop-blur:  5px;
}

/* --- Backdrop -------------------------------------------------------- */

/* Fixed overlay covering the full viewport; blurs the page beneath it.
 * The -webkit- prefix is required for Safari. */
.invent-modal-backdrop {
    background-color:       var(--modal-backdrop-color);
    backdrop-filter:        blur(var(--modal-backdrop-blur));
    -webkit-backdrop-filter: blur(var(--modal-backdrop-blur));
    inset:                  0;
    position:               fixed;
    /* Sit above all page content and Invent widgets. */
    z-index:                99999999;
}

/* --- Modal box ------------------------------------------------------- */

/* Card centred within the backdrop; scrollable if taller than the
 * viewport. Uses existing theme variables so light/dark mode is free. */
.invent-modal {
    background:    var(--main-background);
    border:        var(--border-width) solid var(--primary-light);
    border-radius: var(--border-radius-lg);
    box-shadow:    0 8px 32px rgba(0, 0, 0, 0.2);
    box-sizing:    border-box;
    color:         var(--color-body);
    left:          50%;
    /* Leave breathing room above and below on tall content. */
    max-height:    85vh;
    max-width:     var(--modal-max-width);
    overflow-y:    auto;
    padding:       var(--modal-padding);
    position:      absolute;
    top:           50%;
    transform:     translate(-50%, -50%);
    /* Ensure the box never touches the viewport edges. */
    width:         calc(100% - 2rem);
}

/* --- Dismiss button -------------------------------------------------- */

/* Styled to match the alert widget's dismiss button for consistency.
 * Logical inset property ensures correct placement in RTL layouts. */
.invent-modal > button.dismiss {
    background:       none;
    border:           none;
    color:            inherit;
    cursor:           pointer;
    font-size:        var(--h6-size);
    font-weight:      600;
    inset-inline-end: 0.5rem;
    line-height:      1;
    opacity:          0.6;
    position:         absolute;
    top:              0.5rem;
}

.invent-modal > button.dismiss:hover {
    opacity: 1;
}

/* --- Responsive: narrow screens (breakpoint: 600px) ----------------- */

@media (max-width: 599px) {
    .invent-modal {
        /* Tighter padding on small screens. */
        --modal-padding: 1rem;
    }
}

/* === Rating === */

@keyframes rating-fade-out {
    0%   { opacity: 1;   transform: translateY(0);    }
    70%  { opacity: 1;   transform: translateY(0);    }
    100% { opacity: 0;   transform: translateY(-6px); }
}

.rating {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
    position: relative;
    padding: 4px 8px;
    border-radius: var(--border-radius-lg);
}

.rating-stars {
    display: inline-flex;
    gap: 2px;
}

/* Individual star */

.rating-star {
    position: relative;     /* stacking context for the half-zone overlays */
    display: inline-block;
    font-size: 1.5rem;
    line-height: 1;
    user-select: none;
}

/* The visible star — inherits color/gradient from the state classes below. */
.rating-star-glyph {
    display: block;
    pointer-events: none;   /* clicks fall through to the half zones */
}

/* Fill states */

.rating-star-full .rating-star-glyph {
    color: var(--warning);
}

.rating-star-half .rating-star-glyph {
    background: linear-gradient(
        to right,
        var(--warning) 50%,
        var(--main-background) 50%
    );
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    -webkit-text-stroke: 0.5px var(--warning);
}

.rating-star-empty .rating-star-glyph {
    color: var(--main-background);
    -webkit-text-stroke: 0.5px var(--warning);
}

/* Invisible click zones */

.rating-half {
    position: absolute;
    top: 0;
    bottom: 0;
    width: 50%;
}

.rating-half-left  { left: 0; }
.rating-half-right { right: 0; }

.rating-interactive .rating-half {
    cursor: pointer;
}

.rating-interactive .rating-star:hover .rating-star-glyph {
    display: inline-block;
    transform: scale(1.2);
    transition: transform 0.15s;
}

/* Read-only styles */

.rating-readonly .rating-star-glyph {
    filter: drop-shadow(0 0 0.5px var(--warning));
}

/* Numeric value label */

.rating-value {
    font-size: 0.9rem;
    color: var(--secondary-text, #555);
    min-width: 3ch;
}

/* Popup message */

.rating-message {
    position: absolute;
    bottom: 25%;
    left: 100%;
    transform: translateX(-50%);
    white-space: nowrap;

    font-size: 0.8rem;
    color: var(--color-body);
    background-color: var(--main-background);
    border: 1px solid var(--color-body);
    border-radius: var(--border-radius-lg);
    padding: 3px 10px;

    opacity: 0;
    pointer-events: none;
}

.rating-message-visible {
    animation: rating-fade-out 2.5s ease-in forwards;
}

/* === Divider === */

.divider {
    flex-shrink: 0;
    pointer-events: none;
    border: none;
    box-sizing: border-box; /* Ensures padding/border don't affect total size */
}

.divider-horizontal {
    align-self: stretch;
    border-top: var(--border-width) solid var(--color-body);
    margin: var(--spacing-md) 0;
    width: 100%;
    height: 0;
}

.divider-vertical {
    align-self: stretch;
    border-left: var(--border-width) solid var(--color-body);
    margin: 0 var(--spacing-md);
    width: 0;
    min-height: 1em; 
}
/* === Page transitions === */

/* -- Duration driven by --page-transition-duration, set inline    -- */
/* -- on each page element from its transition_speed property.    -- */

@keyframes invent-fade-in {
    from { opacity: 0; }
    to   { opacity: 1; }
}

@keyframes invent-fade-out {
    from { opacity: 1; }
    to   { opacity: 0; }
}

@keyframes invent-slide-in {
    from { transform: translateX(-100%); }
    to   { transform: translateX(0); }
}

@keyframes invent-slide-out {
    from { transform: translateX(0); }
    to   { transform: translateX(100%); }
}

@keyframes invent-zoom-in {
    from { opacity: 0; transform: scale(0.2); }
    to   { opacity: 1; transform: scale(1); }
}

@keyframes invent-zoom-out {
    from { opacity: 1; transform: scale(1); }
    to   { opacity: 0; transform: scale(0.2); }
}

/* -- Convex: page rotates outward on exit, inward on entry.      -- */
@keyframes invent-convex-in {
    from {
        opacity: 0;
        transform: perspective(2000px)
                   translateX(-100%) rotateY(90deg);
    }
    to {
        opacity: 1;
        transform: perspective(2000px)
                   translateX(0) rotateY(0deg);
    }
}

@keyframes invent-convex-out {
    from {
        opacity: 1;
        transform: perspective(2000px)
                   translateX(0) rotateY(0deg);
    }
    to {
        opacity: 0;
        transform: perspective(2000px)
                   translateX(100%) rotateY(-90deg);
    }
}

/* -- Concave: page rotates inward on exit, outward on entry.     -- */
@keyframes invent-concave-in {
    from {
        opacity: 0;
        transform: perspective(2000px)
                   translateX(-100%) rotateY(-90deg);
    }
    to {
        opacity: 1;
        transform: perspective(2000px)
                   translateX(0) rotateY(0deg);
    }
}

@keyframes invent-concave-out {
    from {
        opacity: 1;
        transform: perspective(2000px)
                   translateX(0) rotateY(0deg);
    }
    to {
        opacity: 0;
        transform: perspective(2000px)
                   translateX(100%) rotateY(90deg);
    }
}

.invent-page--entering-fade {
    animation: invent-fade-in
               var(--page-transition-duration) ease both;
}
.invent-page--leaving-fade {
    animation: invent-fade-out
               var(--page-transition-duration) ease both;
}
.invent-page--entering-slide,
.invent-page--leaving-slide {
    overflow: hidden;
}
.invent-page--entering-slide {
    animation: invent-slide-in
               var(--page-transition-duration) ease both;
}
.invent-page--leaving-slide {
    animation: invent-slide-out
               var(--page-transition-duration) ease both;
}
.invent-page--entering-zoom {
    animation: invent-zoom-in
               var(--page-transition-duration) ease both;
}
.invent-page--leaving-zoom {
    animation: invent-zoom-out
               var(--page-transition-duration) ease both;
}
.invent-page--entering-convex {
    animation: invent-convex-in
               var(--page-transition-duration) ease both;
}
.invent-page--leaving-convex {
    animation: invent-convex-out
               var(--page-transition-duration) ease both;
}
.invent-page--entering-concave {
    animation: invent-concave-in
               var(--page-transition-duration) ease both;
}
.invent-page--leaving-concave {
    animation: invent-concave-out
               var(--page-transition-duration) ease both;
}

/* -- Disable all page animations for users who prefer reduced     -- */
/* -- motion.                                                      -- */
@media (prefers-reduced-motion: reduce) {
    [class*="invent-page--entering-"],
    [class*="invent-page--leaving-"] {
        animation: none;
    }
}