:root {
    color-scheme: dark;

    font-family:
        system-ui,
        -apple-system,
        BlinkMacSystemFont,
        'Segoe UI',
        sans-serif;

    font-size: 14px;

    --page-width: 1200px;
    --field-width: 240px;
    --control-width: 190px;
    --column-gap: 24px;
    --button-gap: 6px;
    --practice-detail-gap: 10px;
    --practice-row-gap: 8px;
    --stats-spacing: 8px;
    --footer-height: 1.7rem;

    --background: #111;
    --surface: #1b1b1b;
    --button: #272727;
    --button-hover: #333;
    --border: #444;
    --muted: #999;
    --text: #eee;
    --mic-accent: crimson;
    --correct: #68d47d;
    --correct-border: #477e52;
    --correct-background: #245d32;
    --correct-emphasis: #8dec9f;
    --incorrect: #ee7474;
    --incorrect-border: #8a4a4a;
    --incorrect-background: #642929;
    --incorrect-emphasis: #ff9090;
    --target: #8ab8ff;
    --target-border: #4a668a;
    --target-background: #263f64;
}

* {
    box-sizing: border-box;
}

html {
    overflow-y: scroll;
}

html,
body {
    margin: 0;
    min-width: 0;
}

body {
    overflow-x: hidden;

    padding-bottom: calc(var(--footer-height) + 0.85rem);

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

button,
input,
select {
    font: inherit;
}

button,
input[type='number'],
select {
    height: 32px;
}

button {
    border: 1px solid var(--border);
    border-radius: 4px;

    background: var(--button);
    color: var(--text);

    cursor: pointer;
}

button:hover:not(:disabled) {
    background: var(--button-hover);
}

button:disabled {
    opacity: 0.42;
    cursor: default;
}

button:focus-visible,
input:focus-visible,
select:focus-visible,
.info-tip:focus-visible {
    outline: 2px solid var(--target);
    outline-offset: 2px;
}

input,
select {
    min-width: 0;

    border: 1px solid var(--border);
    border-radius: 4px;

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

input[type='number'] {
    padding: 2px 8px;
}

select {
    padding: 2px 28px 2px 8px;
}

.page-width {
    width: min(var(--page-width), calc(100% - 28px));
    margin-inline: auto;
}

/* Header */

.topbar {
    border-bottom: 1px solid #303030;
}

.topbar-inner {
    min-height: 64px;

    padding-block: 8px;

    display: grid;
    grid-template-columns: repeat(4, var(--field-width));

    column-gap: var(--column-gap);

    align-items: center;
    justify-content: start;
}

.brand-name {
    grid-column: 1 / 3;

    margin: 0;

    font-size: 28px;
    font-weight: 700;

    white-space: nowrap;
}

.global-volume {
    grid-column: 3;
    min-width: 0;
}

.global-reference {
    grid-column: 4;
    min-width: 0;
}

.global-volume > label,
.global-reference > label {
    display: block;

    margin-bottom: 5px;

    color: #bbb;

    font-size: 12px;
    line-height: 1.2;
}

.global-volume input {
    display: block;

    width: var(--control-width);
    height: 32px;
    margin: 0;
}

.global-reference-controls {
    width: var(--control-width);
    max-width: 100%;

    display: flex;
    align-items: center;

    gap: 6px;
}

.global-reference-controls input {
    width: 0;
    min-width: 0;

    flex: 1;
}

.global-reference-controls button {
    flex: none;

    padding-inline: 8px;
}

/* Tabs */

.tabs {
    overflow-x: auto;
    border-bottom: 1px solid #303030;
}

.tabs-inner {
    min-width: max-content;
    height: 38px;

    display: flex;
    align-items: end;

    gap: 22px;
}

.tab {
    height: 38px;

    padding: 0 2px;

    border: 0;
    border-bottom: 2px solid transparent;
    border-radius: 0;

    background: transparent;
    color: var(--muted);
}

.tab:hover:not(:disabled) {
    background: transparent;
    color: var(--text);
}

.tab.is-active {
    border-bottom-color: #ddd;
    color: #fff;
}

/* Main */

main {
    padding-block: 8px 8px;
}

.tab-panel[hidden] {
    display: none;
}

.sr-only {
    position: absolute;

    width: 1px;
    height: 1px;

    padding: 0;
    margin: -1px;

    overflow: hidden;
    clip-path: inset(50%);

    white-space: nowrap;

    border: 0;
}

.blurb {
    margin: 5px 0 0;

    color: var(--muted);
    line-height: 1.4;
}

/* Form fields */

.form-grid {
    margin-top: 18px;

    display: grid;
    grid-template-columns: repeat(4, var(--field-width));

    gap: 16px var(--column-gap);

    justify-content: start;
}

.field {
    min-width: 0;
}

.field > label {
    display: flex;
    align-items: center;

    width: max-content;
    max-width: 100%;

    margin-bottom: 5px;

    color: #bbb;

    font-size: 12px;
    line-height: 1.2;
}

.control-row {
    min-width: 0;
}

.control-row input[type='number'],
.control-row select {
    width: var(--control-width);
    max-width: 100%;
}

.quality-toggles {
    width: var(--control-width);
    max-width: 100%;

    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
}

.quality-toggles button {
    min-width: 0;
    padding: 0;

    border-radius: 0;

    font-size: 12px;
}

.quality-toggles button:first-child {
    border-radius: 4px 0 0 4px;
}

.quality-toggles button:last-child {
    border-radius: 0 4px 4px 0;
}

.quality-toggles button + button {
    border-left: 0;
}

.quality-toggles button[aria-pressed='true'] {
    background: #3d526e;
    color: #d9e8ff;
}

.range-controls {
    width: var(--control-width);
    max-width: 100%;

    display: flex;
    align-items: center;

    gap: 6px;
}

.range-controls input {
    width: 0;
    min-width: 0;

    flex: 1;
}

.range-controls > span {
    flex: none;
    color: var(--muted);
}

.note-frequency {
    color: #ddd;
}

.frequency-value {
    font-variant-numeric: tabular-nums;
}

.stats,
.pick-target-candidate-details,
.practice-result {
    font-variant-numeric: tabular-nums;
}

/* Tooltips */

.info-tip {
    position: relative;

    display: inline-grid;
    place-items: center;

    margin-left: 4px;

    color: #888;

    font-size: 12px;
    line-height: 1;

    cursor: help;
}

.info-tip:hover,
.info-tip:focus-visible {
    color: #ddd;
}

.info-tip::after {
    content: attr(data-tooltip);

    position: absolute;
    z-index: 50;

    top: calc(100% + 7px);
    left: 50%;

    width: max-content;
    max-width: min(280px, calc(100vw - 24px));

    padding: 7px 9px;

    border: 1px solid #555;
    border-radius: 5px;

    background: #202020;
    color: var(--text);

    font-size: 12px;
    font-weight: 400;
    line-height: 1.35;

    white-space: normal;

    opacity: 0;
    visibility: hidden;

    pointer-events: none;

    transform: translateX(calc(-50% + var(--tooltip-shift-x, 0px)));
}

.info-tip:hover::after,
.info-tip:focus-visible::after {
    opacity: 1;
    visibility: visible;
}

/* Practice layout */

.practice {
    width: max-content;
    max-width: 100%;

    margin-top: 17px;

    display: grid;

    grid-template-columns:
        var(--control-width)
        max-content;

    column-gap: var(--practice-detail-gap);
    row-gap: var(--practice-row-gap);

    align-items: center;
}

.practice-wide {
    width: auto;

    grid-template-columns: repeat(2, var(--field-width));

    column-gap: var(--column-gap);
    row-gap: var(--practice-row-gap);

    align-items: start;
}

.practice-wide-content {
    width: calc(var(--field-width) + var(--column-gap) + var(--control-width));
    max-width: 100%;
}

.tuner-practice {
    grid-template-areas:
        'actions .'
        'meter meter';
}

.metronome-practice {
    grid-template-areas: 'actions .';
}

.pitch-placement-practice {
    grid-template-areas:
        'actions .'
        'placement-judgment result'
        'stats stats';
}

.pick-target-practice {
    grid-template-areas:
        'actions .'
        'candidates candidates'
        'stats stats';
}

.chord-quality-practice {
    grid-template-areas:
        'actions .'
        'answers result'
        'stats stats';
}

.pitch-memory-practice {
    grid-template-areas:
        'actions .'
        'body body'
        'report report';
}

.practice-body {
    grid-area: body;
    min-width: 0;
}

.practice-status {
    min-height: 32px;
    margin: 0 0 8px;

    display: flex;
    align-items: center;

    color: #bbb;
    line-height: 1.4;
}

.practice-body > label {
    display: block;
    margin-bottom: 5px;

    color: #bbb;
    font-size: 12px;
}

.practice-body input[type='range'] {
    display: block;
    width: 100%;
    height: 32px;
    margin: 0 0 6px;
}

.pitch-memory-frequency-scale {
    position: relative;
    display: flow-root;
}

.pitch-memory-frequency-markers {
    position: absolute;
    z-index: 2;
    inset: 4px 8px 10px;

    pointer-events: none;
}

.pitch-memory-frequency-marker {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;

    width: 3px;

    pointer-events: none;
    transform: translateX(-1.5px);
}

.pitch-memory-frequency-marker.is-target {
    background: var(--target);
}

.pitch-memory-frequency-marker.is-response {
    background: var(--incorrect);
}

.pitch-memory-frequency-marker.is-response.is-correct {
    background: var(--correct);
}

.pitch-memory-frequency-scale input.has-result::-webkit-slider-thumb {
    opacity: 0;
}

.pitch-memory-frequency-scale input.has-result::-moz-range-thumb {
    opacity: 0;
}

.response-actions {
    display: flex;
    gap: var(--button-gap);
}

.response-actions button {
    flex: 1;
}

.practice-report {
    grid-area: report;

    display: flex;
    align-items: flex-end;
    gap: 12px;
}

.practice-report .practice-stats {
    margin-top: var(--stats-spacing);
}

.report-actions {
    display: flex;
    align-items: center;
    gap: 12px;

    margin-top: var(--stats-spacing);
}

.report-actions button:first-child {
    padding-inline: 12px;
}

.practice > .action-button-grid {
    grid-area: actions;
}

.practice-stats {
    grid-area: stats;

    margin-top: calc(var(--stats-spacing) - var(--practice-row-gap));
}

.practice-result {
    min-width: 0;
}

.practice-result.is-correct {
    color: var(--correct);
}

.practice-result.is-incorrect {
    color: var(--incorrect);
}

.answer-option.is-correct {
    border-color: var(--correct-border);
    background: var(--correct-background);
    color: var(--correct-emphasis);
}

.answer-option.is-incorrect {
    border-color: var(--incorrect-border);
    background: var(--incorrect-background);
    color: var(--incorrect-emphasis);
}

.answer-option.is-target {
    border-color: var(--target-border);
    background: var(--target-background);
    color: var(--target);
}

.answer-option.is-correct:disabled,
.answer-option.is-incorrect:disabled,
.answer-option.is-target:disabled {
    opacity: 1;
}

/* Action buttons */

.action-button-grid,
.pick-target-candidate-actions {
    width: var(--control-width);
    max-width: 100%;

    display: grid;

    grid-template-columns: repeat(3, minmax(0, 1fr));

    gap: var(--button-gap);

    align-items: center;
}

.action-button-grid [data-action='play-tuner'],
.action-button-grid [data-action='play-metronome'],
.action-button-grid [data-action='play-placement'] {
    grid-column: 1;
}

.action-button-grid [data-action='stop-audio'] {
    grid-column: 2;
}

.action-button-grid [data-action='toggle-tuner-mic'],
.action-button-grid [data-action='tap-tempo'],
.action-button-grid [data-action='new-placement'],
.action-button-grid [data-action='new-pick'] {
    grid-column: 3;
}

.action-button-grid .icon-button,
.pick-target-candidate-actions .icon-button {
    width: 100%;
    min-width: 0;
}

.icon-button {
    min-width: 0;
    height: 32px;

    padding: 0;

    display: inline-grid;
    place-items: center;

    font-size: 15px;
    line-height: 1;
}

/* Tuner */

.tuner-header,
.tuner-footer {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.tuner-mic-button {
    font-size: 12px;
}

.tuner-mic-button.is-active {
    border-color: var(--mic-accent);
    color: var(--mic-accent);
}

.tuner-meter {
    grid-area: meter;
}

.tuner-header {
    min-height: 58px;
}

.tuner-note {
    font-size: 32px;
    font-weight: 700;
    line-height: 1;

    font-variant-numeric: tabular-nums;
}

.tuner-target-frequency {
    margin-top: 6px;

    color: var(--muted);

    font-size: 12px;
    line-height: 1.2;
}

.tuner-gauge {
    padding-top: 4px;
    padding-bottom: 8px;
}

.tuner-scale {
    position: relative;

    height: 16px;

    margin-bottom: 4px;

    color: var(--muted);

    font-size: 10px;
    line-height: 1;

    font-variant-numeric: tabular-nums;
}

.tuner-scale-left,
.tuner-scale-center,
.tuner-scale-right {
    position: absolute;
}

.tuner-scale-left {
    left: 0;
}

.tuner-scale-center {
    left: 50%;

    transform: translateX(-50%);
}

.tuner-scale-right {
    right: 0;
}

.tuner-track {
    position: relative;

    height: 28px;

    border: 1px solid var(--border);
    border-radius: 4px;

    background: var(--surface);
}

/*
 * Each tick represents 10 cents:
 *
 * 10% = -40
 * 20% = -30
 * 30% = -20
 * 40% = -10
 * 50% =   0
 * 60% = +10
 * 70% = +20
 * 80% = +30
 * 90% = +40
 */
.tuner-tick {
    position: absolute;

    top: 8px;
    bottom: 8px;

    width: 1px;

    background: #555;

    transform: translateX(-50%);
}

.tuner-tick-center {
    top: 4px;
    bottom: 4px;

    width: 2px;

    background: #888;
}

.tuner-needle {
    position: absolute;
    z-index: 2;

    top: -5px;
    bottom: -5px;
    left: 50%;

    width: 3px;

    opacity: 0;

    background-color: var(--mic-accent);

    transform: translateX(-50%);

    transition:
        left 120ms ease-out,
        opacity 120ms linear,
        background-color 120ms linear;
}

.tuner-needle.is-visible {
    opacity: 1;
}

.tuner-needle.is-in-tune {
    background-color: var(--correct);
}

.tuner-footer {
    min-height: 40px;
}

.tuner-cents {
    font-size: 21px;
    font-weight: 600;
    line-height: 1;

    font-variant-numeric: tabular-nums;
}

.tuner-detected-frequency {
    margin-top: 6px;

    color: var(--muted);

    font-size: 12px;
    line-height: 1.2;
}

/* Stats */

.stats {
    width: max-content;
    max-width: 100%;
    min-width: 0;

    margin-bottom: 0;

    color: #bbb;

    font-size: 13px;
    line-height: 18px;

    white-space: nowrap;
}

.stats > div {
    display: flex;
    align-items: baseline;

    gap: 4px;
}

.stats > .adaptive-status-row:has(dd:empty) {
    display: none;
}

.stats dt,
.stats dd {
    margin: 0;
}

.stats dt::after {
    content: ':';
}

.stats dd {
    color: #ddd;
    font-weight: 600;
}

.stats-with-action dd {
    display: flex;
    align-items: baseline;

    gap: 8px;
}

.link-button {
    height: auto;
    min-height: 0;

    padding: 0;

    border: 0;

    background: transparent;
    color: var(--muted);

    font-size: 12px;
    line-height: inherit;

    text-decoration: underline;
}

.link-button:hover:not(:disabled) {
    background: transparent;
    color: #fff;
}

/* Pitch placement */

.placement-judgment {
    grid-area: placement-judgment;

    width: var(--control-width);
    max-width: 100%;

    display: flex;

    border: 1px solid var(--border);
    border-radius: 5px;

    overflow: hidden;
}

.placement-judgment button {
    flex: 1;

    min-width: 0;
    height: 32px;

    margin: 0;
    padding: 0;

    border: 0;
    border-radius: 0;

    background: #222;
}

.placement-judgment button + button {
    border-left: 1px solid var(--border);
}

.placement-result {
    grid-area: result;

    white-space: nowrap;
}

/* Placement refresh countdown */

.auto-refresh {
    position: relative;
    overflow: hidden;
}

.auto-refresh::before {
    content: '';

    position: absolute;

    inset: 0;

    background: rgb(255 255 255 / 16%);

    transform: scaleX(0);
    transform-origin: right center;
}

.auto-refresh > span {
    position: relative;
    z-index: 1;
}

.auto-refresh.is-counting-down::before {
    animation: refresh-countdown 3s linear forwards;
}

@keyframes refresh-countdown {
    from {
        transform: scaleX(1);
    }

    to {
        transform: scaleX(0);
    }
}

/* Pick target */

.pick-target-candidate-list {
    grid-area: candidates;

    display: grid;

    grid-template-columns: subgrid;

    row-gap: 5px;
}

.pick-target-candidate-row {
    grid-column: 1 / -1;

    min-width: 0;
    min-height: 32px;

    display: grid;

    grid-template-columns: subgrid;

    align-items: center;
}

.pick-target-candidate-actions {
    grid-column: 1;
}

.pick-target-candidate-play {
    grid-column: 1;
}

.pick-target-candidate-choose {
    grid-column: 2 / 4;

    width: 100%;
    min-width: 0;
    height: 32px;

    padding: 0 7px;

    white-space: nowrap;
}

.pick-target-candidate-details {
    grid-column: 2;

    min-width: 0;

    white-space: nowrap;

    color: #aaa;
}

.pick-target-candidate-result-icon {
    display: inline-block;

    width: 1.4em;

    margin-right: 3px;

    font-weight: 700;
    text-align: center;
}

.pick-target-candidate-row.is-incorrect,
.pick-target-candidate-row.is-incorrect .pick-target-candidate-details {
    color: var(--incorrect);
}

.pick-target-candidate-row.is-target,
.pick-target-candidate-row.is-target .pick-target-candidate-details {
    color: var(--target);
}

.pick-target-candidate-row.is-correct,
.pick-target-candidate-row.is-correct .pick-target-candidate-details {
    color: var(--correct);
}

/* Chord quality */

.chord-answers {
    grid-area: answers;

    width: var(--control-width);
    max-width: 100%;

    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));

    gap: var(--button-gap);
}

.chord-result {
    grid-area: result;

    font-size: 13px;
    white-space: nowrap;
}

/* Pitch memory */

.pitch-memory-detected-frequency {
    min-height: 32px;
    margin-bottom: 6px;

    line-height: 32px;
}

.pitch-memory-result {
    min-height: 20px;
    margin-top: 8px;
}

.pitch-memory-result:empty {
    display: none;
}

/* Footer */

footer {
    position: fixed;
    z-index: 100;

    right: 0;
    bottom: 0;
    left: 0;
    height: var(--footer-height);

    display: flex;
    justify-content: space-between;
    align-items: center;

    padding: 0 1rem;

    font-size: 0.85rem;

    color: #aaa;
    background: #181818;

    border-top: 1px solid #333;

    line-height: 1.6;
}

.footer-source {
    text-align: left;
}

.footer-socials {
    text-align: right;
    padding-top: 2px;
}

footer a {
    color: #bbb;
}

footer a:hover {
    text-decoration: none;
}

/* Tablet */
@media (max-width: 1060px) {
    .topbar-inner,
    .form-grid {
        grid-template-columns: repeat(3, var(--field-width));
    }

    .brand-name {
        grid-column: 1;
    }

    .global-volume {
        grid-column: 2;
    }

    .global-reference {
        grid-column: 3;
    }
}

@media (max-width: 800px) {
    .form-grid {
        grid-template-columns: repeat(2, var(--field-width));
    }

    .topbar-inner {
        grid-template-columns: repeat(2, var(--field-width));

        grid-template-areas:
            'brand brand'
            'volume reference';

        column-gap: var(--column-gap);
        row-gap: 8px;
    }

    .brand-name {
        grid-area: brand;
    }

    .global-volume {
        grid-area: volume;
    }

    .global-reference {
        grid-area: reference;
    }
}

@media (max-width: 560px) {
    :root {
        --column-gap: 12px;

        --field-width: calc((100vw - 40px) / 2);
        --control-width: min(190px, var(--field-width));
    }

    .page-width {
        width: calc(100% - 16px);
    }

    .topbar-inner {
        grid-template-columns: repeat(2, var(--field-width));

        column-gap: var(--column-gap);
        row-gap: 8px;
    }

    .brand-name {
        min-width: 0;

        font-size: clamp(18px, 5.5vw, 28px);
        white-space: nowrap;
    }

    .global-reference-controls button {
        padding-inline: 6px;
    }

    .form-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .control-row input[type='number'],
    .control-row select,
    .range-controls {
        width: 100%;
    }

    .practice {
        width: 100%;

        grid-template-columns:
            var(--control-width)
            minmax(0, 1fr);
    }

    .pitch-memory-practice {
        grid-template-columns: minmax(0, 1fr);
        grid-template-areas:
            'actions'
            'body'
            'report';

        row-gap: 14px;
    }

    .practice-wide-content {
        width: 100%;
    }

    .tuner-practice {
        grid-template-columns: minmax(0, 1fr);

        grid-template-areas:
            'actions'
            'meter';

        row-gap: 14px;
    }

    .tuner-note {
        font-size: 28px;
    }

    .tuner-cents {
        font-size: 19px;
    }

    .action-button-grid,
    .pick-target-candidate-actions,
    .placement-judgment {
        width: var(--control-width);
    }

    .placement-result,
    .chord-result,
    .practice-body,
    .pick-target-candidate-details {
        white-space: normal;

        overflow-wrap: anywhere;
    }

    .info-tip::after {
        position: fixed;

        top: 50%;
        right: 12px;
        left: 12px;

        width: auto;
        max-width: none;

        transform: translateY(-50%);
    }

    footer {
        flex-direction: row;
        align-items: center;

        gap: 12px;

        white-space: nowrap;
    }

    .footer-source {
        flex: none;
        font-size: 0.75rem;
    }

    .footer-socials {
        min-width: 0;

        overflow: hidden;

        text-overflow: ellipsis;
    }
}

/* Very narrow phones: only then switch to one column. */
@media (max-width: 340px) {
    :root {
        --field-width: 100%;
        --control-width: min(190px, 100%);
    }

    .topbar-inner {
        grid-template-columns: minmax(0, 1fr);

        grid-template-areas:
            'brand'
            'volume'
            'reference';
    }

    .form-grid {
        grid-template-columns: minmax(0, 1fr);
    }

    .brand-name {
        font-size: 22px;
    }
}