/*
 * Article audio player. Class names stay article-tts so existing theme
 * overrides that remap --tts-* tokens keep working.
 *
 * Base is shared by many customer sites, so nothing here is hardcoded to a
 * palette: every colour, shape, font and spacing value is read from a token
 * declared once on .article-tts. Each token falls back through the theme
 * variable to a neutral default, so an instance theme only has to remap tokens
 * (see web/css/override-blocks.css) instead of restating layout.
 *
 * State classes toggled by js/articleTts.js on the root element:
 *   is-enhanced, is-ready, is-playing, is-buffering, is-seeking, is-muted,
 *   has-duration, has-error   (+ is-pressed / is-changed on single controls)
 */

.article-tts {
    /* palette */
    --tts-accent: var(--primary, #1b3a5c);
    --tts-accent-contrast: var(--light, #fff);
    --tts-surface: var(--lightblue, #f2f6fa);
    --tts-on-surface: var(--dark, #16181a);
    /* Accent is only safe for large and non-text parts: text needs its own token
       so contrast never depends on how bright a customer's brand colour is. */
    --tts-accent-text: var(--tts-on-surface);
    --tts-muted: rgba(22, 24, 26, 0.66);
    /* 0.5 composites to ≥ 3:1 on white and on --tts-surface (WCAG 1.4.11). */
    --tts-track: rgba(22, 24, 26, 0.5);
    --tts-track-buffered: rgba(22, 24, 26, 0.6);
    --tts-halo: rgba(22, 24, 26, 0.09);
    --tts-error: var(--danger, #b3261e);

    /* shape */
    --tts-radius: 999px;
    --tts-radius-surface: 4px;
    --tts-track-radius: 999px;
    --tts-toggle-radius: 50%;
    --tts-thumb-radius: 50%;
    --tts-track-height: 6px;
    --tts-thumb-size: 14px;
    --tts-hit: 44px;
    --tts-control-size: 44px;
    --tts-border-width: 1px;

    /* typography */
    --tts-font: inherit;
    --tts-font-size: 0.9375rem;
    --tts-note-size: 0.8125rem;
    --tts-letter-spacing: normal;

    /* spacing */
    --tts-gap: 0.75rem;
    --tts-gap-tight: 0.375rem;
    --tts-row-gap: 0.5rem;
    --tts-pad-y: 0.75rem;
    --tts-pad-x: 1rem;
    --tts-note-space: 0.5rem;

    /* motion */
    --tts-duration: 180ms;
    --tts-duration-slow: 320ms;
    --tts-ease: cubic-bezier(0.4, 0, 0.2, 1);

    /* live state, written by the JS */
    --tts-progress: 0;
    --tts-buffered: 0;
    --tts-volume: 100;

    box-sizing: border-box;
    display: block;
    margin: 1rem 0 1.5rem;
    max-width: 42rem;
    font-family: var(--tts-font);
    color: var(--tts-on-surface);
}

.article-tts *,
.article-tts *::before,
.article-tts *::after {
    box-sizing: border-box;
}

/* Variants -------------------------------------------------------------- */

.article-tts[data-tts-variant="bare"] {
    padding: 0;
    background: transparent;
}

.article-tts[data-tts-variant="surface"] {
    padding: var(--tts-pad-y) var(--tts-pad-x);
    border-radius: var(--tts-radius-surface);
    background: var(--tts-surface);
}

/* Progressive enhancement ---------------------------------------------- */

/*
 * The enhanced element never carries "controls", so it has no box of its own and
 * cannot flash before the JS runs. Visitors without JS get the <noscript> copy.
 */
.article-tts-fallback {
    display: block;
    width: 100%;
    max-width: 420px;
}

.article-tts-controls {
    display: none;
}

.article-tts.is-enhanced .article-tts-controls {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--tts-row-gap) var(--tts-gap);
}

.article-tts.is-enhanced .article-tts-controls[hidden] {
    display: flex;
}

/* Entrance + playing pulse --------------------------------------------- */

.article-tts.is-ready {
    animation: tts-enter var(--tts-duration-slow) var(--tts-ease) both;
}

@keyframes tts-enter {
    from {
        opacity: 0;
        transform: translateY(6px);
    }

    to {
        opacity: 1;
        transform: none;
    }
}

@keyframes tts-pulse {
    0%,
    100% {
        box-shadow: 0 0 0 0 var(--tts-halo);
    }

    50% {
        box-shadow: 0 0 0 7px var(--tts-halo);
    }
}

/* Play / pause --------------------------------------------------------- */

.article-tts-toggle {
    position: relative;
    flex: 0 0 auto;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: var(--tts-control-size);
    height: var(--tts-control-size);
    margin: 0;
    padding: 0;
    border: 0;
    border-radius: var(--tts-toggle-radius);
    background: var(--tts-accent);
    color: var(--tts-accent-contrast);
    line-height: 0;
    cursor: pointer;
    -webkit-appearance: none;
    appearance: none;
    transition: transform var(--tts-duration) var(--tts-ease),
                box-shadow var(--tts-duration) var(--tts-ease);
}

.article-tts-toggle:hover {
    transform: scale(1.06);
}

.article-tts-toggle:active {
    transform: scale(0.94);
}

.article-tts.is-playing .article-tts-toggle {
    animation: tts-pulse 2.6s var(--tts-ease) infinite;
}

/* press ripple */
.article-tts-toggle::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: var(--tts-toggle-radius);
    background: var(--tts-accent-contrast);
    opacity: 0;
    transform: scale(0.55);
    pointer-events: none;
}

.article-tts-toggle.is-pressed::before {
    animation: tts-ripple 480ms var(--tts-ease);
}

@keyframes tts-ripple {
    from {
        opacity: 0.42;
        transform: scale(0.55);
    }

    to {
        opacity: 0;
        transform: scale(1.25);
    }
}

/* buffering ring */
.article-tts-toggle::after {
    content: '';
    position: absolute;
    inset: -4px;
    border-radius: var(--tts-toggle-radius);
    background: conic-gradient(from 0deg, transparent 0 55%, var(--tts-accent) 100%);
    opacity: 0;
    transition: opacity var(--tts-duration) var(--tts-ease);
    pointer-events: none;
    -webkit-mask: radial-gradient(farthest-side, transparent calc(100% - 3px), #000 calc(100% - 2.5px));
    mask: radial-gradient(farthest-side, transparent calc(100% - 3px), #000 calc(100% - 2.5px));
}

.article-tts.is-buffering .article-tts-toggle::after {
    opacity: 1;
    animation: tts-spin 900ms linear infinite;
}

@keyframes tts-spin {
    to {
        transform: rotate(360deg);
    }
}

.article-tts-icon {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transform: scale(0.78);
    transition: opacity var(--tts-duration) var(--tts-ease),
                transform var(--tts-duration) var(--tts-ease);
    pointer-events: none;
}

.article-tts-icon svg {
    display: block;
    fill: currentColor;
}

.article-tts-icon-play,
.article-tts-icon-unmuted {
    opacity: 1;
    transform: scale(1);
}

.article-tts.is-playing .article-tts-icon-play {
    opacity: 0;
    transform: scale(0.78);
}

.article-tts.is-playing .article-tts-icon-pause {
    opacity: 1;
    transform: scale(1);
}

.article-tts.is-muted .article-tts-icon-unmuted {
    opacity: 0;
    transform: scale(0.78);
}

.article-tts.is-muted .article-tts-icon-muted {
    opacity: 1;
    transform: scale(1);
}

/* Seek ----------------------------------------------------------------- */

.article-tts-track {
    position: relative;
    flex: 1 1 10rem;
    display: flex;
    align-items: center;
    min-width: 6rem;
    height: var(--tts-hit);
}

/* rail */
.article-tts-track::before {
    content: '';
    position: absolute;
    left: 0;
    right: 0;
    top: 50%;
    height: var(--tts-track-height);
    border-radius: var(--tts-track-radius);
    background-color: var(--tts-track);
    background-repeat: no-repeat;
    background-size: 45% 100%;
    background-position: -45% 50%;
    transform: translateY(-50%);
    pointer-events: none;
}

.article-tts.is-buffering .article-tts-track::before {
    background-image: linear-gradient(90deg, transparent, var(--tts-track-buffered), transparent);
    animation: tts-shimmer 1.15s linear infinite;
}

@keyframes tts-shimmer {
    from {
        background-position: -45% 50%;
    }

    to {
        background-position: 145% 50%;
    }
}

/* buffered range */
.article-tts-buffered {
    position: absolute;
    left: 0;
    top: 50%;
    height: var(--tts-track-height);
    width: calc(var(--tts-buffered) * 1%);
    max-width: 100%;
    border-radius: var(--tts-track-radius);
    background: var(--tts-track-buffered);
    transform: translateY(-50%);
    transition: width 240ms linear;
    pointer-events: none;
}

/* played fill */
.article-tts-track::after {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    height: var(--tts-track-height);
    width: calc(var(--tts-progress) * 1%);
    max-width: 100%;
    border-radius: var(--tts-track-radius);
    background: var(--tts-accent);
    transform: translateY(-50%);
    transition: width 100ms linear;
    pointer-events: none;
}

.article-tts.is-seeking .article-tts-track::after {
    transition: none;
}

.article-tts input[type="range"] {
    position: relative;
    z-index: 2;
    margin: 0;
    padding: 0;
    border: 0;
    background-color: transparent;
    color: var(--tts-accent);
    font: inherit;
    cursor: pointer;
    -webkit-appearance: none;
    appearance: none;
}

.article-tts input[type="range"]:disabled {
    cursor: default;
    opacity: 0.55;
}

.article-tts-seek {
    width: 100%;
    height: var(--tts-hit);
}

.article-tts input[type="range"]::-webkit-slider-runnable-track {
    height: var(--tts-hit);
    border: 0;
    background: transparent;
}

.article-tts input[type="range"]::-moz-range-track {
    height: var(--tts-hit);
    border: 0;
    background: transparent;
}

.article-tts input[type="range"]::-moz-range-progress {
    background: transparent;
}

.article-tts input[type="range"]::-webkit-slider-thumb {
    width: var(--tts-thumb-size);
    height: var(--tts-thumb-size);
    margin-top: calc((var(--tts-hit) - var(--tts-thumb-size)) / 2);
    border: 0;
    border-radius: var(--tts-thumb-radius);
    background: var(--tts-accent);
    transition: transform var(--tts-duration) var(--tts-ease);
    -webkit-appearance: none;
    appearance: none;
}

.article-tts input[type="range"]::-moz-range-thumb {
    width: var(--tts-thumb-size);
    height: var(--tts-thumb-size);
    border: 0;
    border-radius: var(--tts-thumb-radius);
    background: var(--tts-accent);
    transition: transform var(--tts-duration) var(--tts-ease);
}

.article-tts input[type="range"]:hover::-webkit-slider-thumb,
.article-tts input[type="range"]:focus-visible::-webkit-slider-thumb {
    transform: scale(1.35);
}

.article-tts input[type="range"]:hover::-moz-range-thumb,
.article-tts input[type="range"]:focus-visible::-moz-range-thumb {
    transform: scale(1.35);
}

.article-tts.is-seeking .article-tts-seek::-webkit-slider-thumb {
    transform: scale(1.5);
}

.article-tts.is-seeking .article-tts-seek::-moz-range-thumb {
    transform: scale(1.5);
}

.article-tts .article-tts-seek:disabled::-webkit-slider-thumb {
    transform: scale(0.8);
    background: var(--tts-track-buffered);
}

.article-tts .article-tts-seek:disabled::-moz-range-thumb {
    transform: scale(0.8);
    background: var(--tts-track-buffered);
}

/* Remaining time ------------------------------------------------------- */

.article-tts-time {
    flex: 0 0 auto;
    min-width: 3.25rem;
    font-size: var(--tts-font-size);
    line-height: 1.2;
    font-variant-numeric: tabular-nums;
    text-align: right;
    color: var(--tts-muted);
}

.article-tts-time[hidden] {
    display: none;
}

/* Playback speed ------------------------------------------------------- */

.article-tts-speed {
    flex: 0 0 auto;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 3.5rem;
    min-height: var(--tts-hit);
    margin: 0;
    padding: 0 0.75rem;
    overflow: hidden;
    border: var(--tts-border-width) solid var(--tts-accent);
    border-radius: var(--tts-radius);
    background: transparent;
    color: var(--tts-accent-text);
    font-family: inherit;
    font-size: var(--tts-font-size);
    font-variant-numeric: tabular-nums;
    letter-spacing: var(--tts-letter-spacing);
    line-height: 1.2;
    cursor: pointer;
    -webkit-appearance: none;
    appearance: none;
    transition: background-color var(--tts-duration) var(--tts-ease),
                color var(--tts-duration) var(--tts-ease),
                transform var(--tts-duration) var(--tts-ease);
}

/* A tinted hover rather than an accent fill: white-on-accent pill text would
   drop below 4.5:1 on a bright brand colour. */
.article-tts-speed:hover {
    background: var(--tts-halo);
}

.article-tts-speed:active {
    transform: scale(0.95);
}

.article-tts-speed-value {
    display: block;
}

.article-tts-speed.is-changed .article-tts-speed-value {
    animation: tts-speed-in 220ms var(--tts-ease);
}

@keyframes tts-speed-in {
    from {
        opacity: 0;
        transform: translateY(0.55em);
    }

    to {
        opacity: 1;
        transform: none;
    }
}

.article-tts-speed-group {
    position: relative;
    flex: 0 0 auto;
}

/* Volume --------------------------------------------------------------- */

.article-tts-volume-group {
    flex: 0 0 auto;
    display: inline-flex;
    align-items: center;
    gap: var(--tts-gap-tight);
}

.article-tts-mute {
    position: relative;
    flex: 0 0 auto;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: var(--tts-hit);
    height: var(--tts-hit);
    margin: 0;
    padding: 0;
    border: 0;
    border-radius: var(--tts-toggle-radius);
    background: transparent;
    color: var(--tts-accent);
    line-height: 0;
    cursor: pointer;
    -webkit-appearance: none;
    appearance: none;
    transition: background-color var(--tts-duration) var(--tts-ease);
}

.article-tts-mute:hover {
    background: var(--tts-halo);
}

.article-tts-volume-track {
    position: relative;
    display: flex;
    align-items: center;
    width: 5rem;
    height: var(--tts-hit);
}

.article-tts-volume-track::before {
    content: '';
    position: absolute;
    left: 0;
    right: 0;
    top: 50%;
    height: var(--tts-track-height);
    border-radius: var(--tts-track-radius);
    background: var(--tts-track);
    transform: translateY(-50%);
    pointer-events: none;
}

.article-tts-volume-track::after {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    height: var(--tts-track-height);
    width: calc(var(--tts-volume) * 1%);
    max-width: 100%;
    border-radius: var(--tts-track-radius);
    background: var(--tts-accent);
    transform: translateY(-50%);
    pointer-events: none;
}

.article-tts.is-muted .article-tts-volume-track::after {
    background: var(--tts-track);
}

.article-tts-volume {
    position: relative;
    z-index: 2;
    width: 100%;
    height: var(--tts-hit);
}

/* Note + status -------------------------------------------------------- */

.article-tts-note {
    margin: var(--tts-note-space) 0 0;
    font-size: var(--tts-note-size);
    line-height: 1.35;
    color: var(--tts-muted);
}

/* Stays in the accessibility tree while empty so the live region keeps working. */
.article-tts-status {
    margin: 0;
    font-size: var(--tts-font-size);
    line-height: 1.3;
    color: var(--tts-on-surface);
}

.article-tts.has-error .article-tts-status {
    margin-top: var(--tts-note-space);
    color: var(--tts-error);
}

/* Focus ---------------------------------------------------------------- */

.article-tts button:focus,
.article-tts input[type="range"]:focus {
    outline: none;
}

.article-tts button:focus-visible,
.article-tts input[type="range"]:focus-visible {
    outline: 2px solid var(--tts-accent);
    outline-offset: 2px;
}

/* Narrow screens ------------------------------------------------------- */

@media (max-width: 30rem) {
    .article-tts-track {
        flex: 1 1 100%;
        order: 3;
    }
}

/* Reduced motion ------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
    .article-tts.is-ready,
    .article-tts.is-playing .article-tts-toggle,
    .article-tts.is-buffering .article-tts-toggle::after,
    .article-tts.is-buffering .article-tts-track::before,
    .article-tts-toggle.is-pressed::before,
    .article-tts-speed.is-changed .article-tts-speed-value {
        animation: none;
    }

    .article-tts.is-buffering .article-tts-toggle::after {
        opacity: 0;
    }

    .article-tts.is-buffering .article-tts-track::before {
        background-image: none;
    }

    .article-tts *,
    .article-tts *::before,
    .article-tts *::after {
        transition-duration: 1ms !important;
    }

    .article-tts-toggle:hover,
    .article-tts-toggle:active,
    .article-tts-speed:active,
    .article-tts input[type="range"]:hover::-webkit-slider-thumb,
    .article-tts input[type="range"]:focus-visible::-webkit-slider-thumb,
    .article-tts input[type="range"]:hover::-moz-range-thumb,
    .article-tts input[type="range"]:focus-visible::-moz-range-thumb {
        transform: none;
    }
}