/* Main styles for the tutorial site */
:root {
    --primary: #245ea8;
    --primary-dark: #164374;
    --text: #222831;
    --text-light: #616161;
    --bg: #ffffff;
    --bg-soft: #f6f7f9;
    --bg-code: #f3f4f6;
    --border: #d9dee7;
    --accent: #b25c2b;
    --primary-contrast: #ffffff;
    --form-bg: #ffffff;
    --form-text: #222831;
    --concept-bg: #fff3e0;
    --concept-text: #3c2b16;
    --concept-name: #e65100;
    --exercise-bg: #e8f5e9;
    --exercise-text: #173d1b;
    --exercise-title: #2e7d32;
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --primary: #8ab4f8;
        --primary-dark: #c7ddff;
        --text: #e8eaed;
        --text-light: #b4bdc9;
        --bg: #11151b;
        --bg-soft: #1a2029;
        --bg-code: #151922;
        --border: #303946;
        --accent: #f0a36a;
        --primary-contrast: #0b1624;
        --form-bg: #202734;
        --form-text: #e8eaed;
        --concept-bg: #332416;
        --concept-text: #f5dfc5;
        --concept-name: #ffb06c;
        --exercise-bg: #173222;
        --exercise-text: #d7f2df;
        --exercise-title: #88d08e;
    }
}

:root[data-theme="dark"] {
    --primary: #8ab4f8;
    --primary-dark: #c7ddff;
    --text: #e8eaed;
    --text-light: #b4bdc9;
    --bg: #11151b;
    --bg-soft: #1a2029;
    --bg-code: #151922;
    --border: #303946;
    --accent: #f0a36a;
    --primary-contrast: #0b1624;
    --form-bg: #202734;
    --form-text: #e8eaed;
    --concept-bg: #332416;
    --concept-text: #f5dfc5;
    --concept-name: #ffb06c;
    --exercise-bg: #173222;
    --exercise-text: #d7f2df;
    --exercise-title: #88d08e;
}

* {
    box-sizing: border-box;
}

body {
    font-family: system-ui, -apple-system, sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
    max-width: 980px;
    margin: 0 auto;
    padding: 24px;
}

h1, h2, h3 {
    color: var(--text);
    margin-top: 1.5em;
}

h1 { font-size: 2.1em; margin: 0 0 0.25em; }
h2 { font-size: 1.35em; border-bottom: 1px solid var(--border); padding-bottom: 0.3em; }
h3 { font-size: 1.2em; }

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

a:hover {
    text-decoration: underline;
}

/* Breadcrumb navigation */
.breadcrumb {
    color: var(--text-light);
    font-size: 0.9em;
    margin-bottom: 1.5em;
    display: flex;
    gap: 0.5em;
    flex-wrap: wrap;
}

.breadcrumb a {
    color: var(--text-light);
}

.page-header {
    margin-bottom: 1em;
}

.chapter-label {
    color: var(--accent);
    font-weight: 700;
    margin: 0 0 0.35em;
    text-transform: uppercase;
    letter-spacing: 0;
    font-size: 0.85em;
}

.subtitle {
    color: var(--text-light);
    margin-top: 0;
}

.chapter-toc {
    background: var(--bg-soft);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 1em 1.25em;
    margin: 1.5em 0 2em;
}

.chapter-toc h2 {
    margin: 0 0 0.5em;
    border: 0;
    padding: 0;
    font-size: 1.05em;
}

.chapter-toc ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
    gap: 0.25em 1em;
}

.chapter-toc li {
    padding: 0.2em 0;
}

.chapter-toc li.current a {
    color: var(--text);
    font-weight: 700;
}

/* Description block */
.description {
    background: var(--bg-soft);
    border-left: 4px solid var(--primary);
    padding: 1em;
    margin: 1em 0;
    border-radius: 0 4px 4px 0;
}

/* Page sections */
.page-section {
    margin: 2em 0;
}

/* Code blocks */
.code-example {
    --kfsb-control-card: #ffffff;
    --kfsb-control-ink: #222831;
    --kfsb-control-muted: #536273;
    --kfsb-control-write: #245ea8;
    margin: 1em 0;
    border: 1px solid var(--border);
    border-radius: 4px;
    overflow: hidden;
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) .code-example {
        --kfsb-control-card: #1b1e24;
        --kfsb-control-ink: #e8eaed;
        --kfsb-control-muted: #adb4bf;
        --kfsb-control-write: #4a89dc;
    }
}

:root[data-theme="dark"] .code-example {
    --kfsb-control-card: #1b1e24;
    --kfsb-control-ink: #e8eaed;
    --kfsb-control-muted: #adb4bf;
    --kfsb-control-write: #4a89dc;
}

.variant-controls {
    display: flex;
    flex-wrap: wrap;
    gap: 0.375rem;
    align-items: center;
    background: var(--bg-soft);
    border-bottom: 1px solid var(--border);
    padding: 0.65em 1em;
    font-size: 0.9em;
}

fieldset.variant-controls {
    border: 0;
    margin: 0.5rem 0;
}

.variant-controls legend {
    color: var(--kfsb-ink, var(--kfsb-control-ink, #222831));
    font-weight: 600;
    margin-right: 0.5rem;
    padding: 0;
}

.variant-controls label {
    display: inline-flex;
    align-items: center;
    gap: 0.5em;
    color: var(--text-light);
    font-weight: 600;
}

.variant-controls select {
    font: inherit;
    color: var(--form-text);
    background: var(--form-bg);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 0.25em 1.8em 0.25em 0.5em;
}

.kfsb-vpick {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
    pointer-events: none;
}

.variant-controls .kfsb-vlabel {
    display: inline-flex;
    align-items: center;
    padding: 0.15rem 0.55rem;
    border: 1px solid var(--kfsb-muted, var(--kfsb-control-muted, #536273));
    border-radius: 9999px;
    cursor: pointer;
    font-size: 0.85em;
    line-height: 1.5;
    background: var(--kfsb-card, var(--kfsb-control-card, #ffffff));
    color: var(--kfsb-ink, var(--kfsb-control-ink, #222831));
    user-select: none;
}

.variant-controls .kfsb-vlabel:hover {
    border-color: var(--kfsb-muted, var(--kfsb-control-muted, #536273));
}

/* Existing radio-based pages carry an inline, hardcoded selected color.
   Override it through their stable -oN id/for contract until those pages
   can be regenerated from a tracked radio-template source. */
.code-example:has(> .kfsb-vpick[id$="-o0"]:checked) > .variant-controls > .kfsb-vlabel[for$="-o0"],
.code-example:has(> .kfsb-vpick[id$="-o1"]:checked) > .variant-controls > .kfsb-vlabel[for$="-o1"],
.code-example:has(> .kfsb-vpick[id$="-o2"]:checked) > .variant-controls > .kfsb-vlabel[for$="-o2"],
.code-example:has(> .kfsb-vpick[id$="-o3"]:checked) > .variant-controls > .kfsb-vlabel[for$="-o3"],
.code-example:has(> .kfsb-vpick[id$="-o4"]:checked) > .variant-controls > .kfsb-vlabel[for$="-o4"],
.code-example:has(> .kfsb-vpick[id$="-o5"]:checked) > .variant-controls > .kfsb-vlabel[for$="-o5"],
.code-example:has(> .kfsb-vpick[id$="-o6"]:checked) > .variant-controls > .kfsb-vlabel[for$="-o6"],
.code-example:has(> .kfsb-vpick[id$="-o7"]:checked) > .variant-controls > .kfsb-vlabel[for$="-o7"],
.code-example:has(> .kfsb-vpick[id$="-o8"]:checked) > .variant-controls > .kfsb-vlabel[for$="-o8"] {
    background: var(--kfsb-write, var(--kfsb-control-write, #245ea8)) !important;
    color: var(--kfsb-card, var(--kfsb-control-card, #ffffff)) !important;
    border-color: var(--kfsb-write, var(--kfsb-control-write, #245ea8));
}

.code-example:has(.kfsb-vpick:focus-visible) .variant-controls {
    outline: 2px solid var(--kfsb-write, var(--kfsb-control-write, #245ea8));
    outline-offset: 2px;
}

.inline-variant-value {
    color: inherit;
    font: inherit;
}

.inline-variant-select {
    font: inherit;
    font-family: inherit;
    color: var(--form-text);
    background: var(--form-bg);
    border: 1px solid var(--primary);
    border-radius: 4px;
    padding: 0 1.4em 0 0.25em;
    min-width: 3.2em;
}

/* Code example tabs */
.code-tabs {
    display: flex;
    align-items: center;
    gap: 0.25em;
    background: var(--bg-code);
    padding: 0.5em 1em;
    border-bottom: 1px solid var(--border);
}

.tab-btn {
    padding: 0.4em 0.8em;
    border: 1px solid var(--border);
    border-radius: 4px 4px 0 0;
    background: var(--bg);
    color: var(--text-light);
    cursor: pointer;
    font-size: 0.85em;
    font-family: inherit;
}

.tab-btn:hover {
    background: var(--bg-code);
    color: var(--text);
}

.tab-btn.active {
    background: var(--primary);
    color: var(--primary-contrast);
    border-color: var(--primary);
}

.code-tabs .filename {
    margin-left: auto;
    font-family: monospace;
    font-size: 0.85em;
    color: var(--text-light);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.source-variant,
.play-variant {
    display: none;
}

.source-variant.active,
.play-variant.active {
    display: block;
}

.tab-content.play iframe.play-variant.active {
    width: 100%;
    height: 400px;
    background: #1e1e1e;
    border: none;
}

.tab-content.play .execvis-embed.play-variant.active {
    display: block;
    width: 100%;
    min-height: 320px;
    background: #1e1e1e;
    overflow-x: auto;
}

.text-replay {
    background: #151a21;
    color: #dbe7f3;
    min-height: 320px;
}

.text-replay-toolbar {
    display: flex;
    align-items: center;
    gap: 0.5em;
    padding: 0.75em 1em;
    border-bottom: 1px solid #2d3642;
    background: #202834;
}

.text-replay-toolbar button {
    border: 1px solid #526174;
    border-radius: 4px;
    background: #edf3f8;
    color: #18202a;
    font: inherit;
    font-size: 0.85em;
    padding: 0.35em 0.75em;
    cursor: pointer;
}

.text-replay-counter {
    margin-left: auto;
    font-family: 'JetBrains Mono', 'Fira Code', Consolas, monospace;
    color: #b6c7d8;
    font-size: 0.85em;
}

.text-replay-frames {
    list-style: decimal-leading-zero;
    margin: 0;
    padding: 1em 1em 1em 3.25em;
    font-family: 'JetBrains Mono', 'Fira Code', Consolas, monospace;
    font-size: 0.9em;
}

.text-replay-frames li {
    padding: 0.35em 0.65em;
    margin: 0.1em 0;
    border-radius: 4px;
    color: #8190a3;
}

.text-replay-frames li.past {
    color: #b7c5d5;
}

.text-replay-frames li.active {
    color: #ffffff;
    background: #2b5f8f;
}

pre {
    margin: 0;
    padding: 1em;
    background: var(--bg-code);
    overflow-x: auto;
}

pre.source-variant {
    max-width: 100%;
    white-space: pre-wrap;
    overflow-wrap: anywhere;
}

pre.source-variant code {
    white-space: inherit;
    overflow-wrap: inherit;
}

code {
    font-family: 'JetBrains Mono', 'Fira Code', Consolas, monospace;
    font-size: 0.9em;
    /* Long unbreakable tokens (file paths, identifiers) in plain inline <code> overflowed the document:
       measured 240 px on /html/document_skeleton at 375 px wide. The two sibling rules above already
       wrap code inside a source-variant block; plain inline code was simply never wrapped. */
    overflow-wrap: anywhere;
}

/* Help markers - info icon with click-to-toggle tooltip */
.help-marker {
    display: inline-block;
    margin-left: 0.5em;
    color: var(--primary);
    cursor: pointer;
    font-style: normal;
    user-select: none;
}

.help-marker:hover {
    color: var(--primary-dark);
}

.help-tooltip {
    display: none;
    background: #333;
    color: white;
    padding: 0.5em 0.75em;
    border-radius: 4px;
    font-size: 0.85rem;
    font-family: system-ui, sans-serif;
    white-space: pre-wrap;
    max-width: 400px;
    margin-top: 0.25em;
    margin-left: 2em;
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.help-tooltip.show {
    display: block;
}

/* Concepts */
.concept {
    background: var(--concept-bg);
    border-left: 4px solid #f57c00;
    color: var(--concept-text);
    padding: 0.75em 1em;
    margin: 0.75em 0;
    border-radius: 0 4px 4px 0;
}

.concept-name {
    color: var(--concept-name);
}

/* Exercises */
.exercise {
    background: var(--exercise-bg);
    border-left: 4px solid #4caf50;
    color: var(--exercise-text);
    padding: 1em;
    margin: 1em 0;
    border-radius: 0 4px 4px 0;
}

.exercise h3 {
    margin-top: 0;
    color: var(--exercise-title);
}

/* Diagrams */
.diagram {
    margin: 1em 0;
    text-align: center;
}

.diagram svg {
    max-width: 100%;
    height: auto;
}

/* Pagination */
.pagination {
    display: flex;
    justify-content: space-between;
    gap: 1em;
    margin-top: 3em;
    padding-top: 1em;
    border-top: 1px solid var(--border);
}

.pagination a {
    display: inline-block;
    padding: 0.5em 1em;
    background: var(--bg-code);
    border-radius: 4px;
}

.pagination .toc-link {
    margin-left: auto;
    margin-right: auto;
}

/* Index pages */
.index h1 {
    color: var(--primary);
}

.home-hero {
    margin: 0 0 1.75em;
    padding: 0 0 1.25em;
    border-bottom: 1px solid var(--border);
}

.home-hero h1 {
    margin-bottom: 0.25em;
}

.home-hero__lede {
    max-width: 760px;
    margin: 0;
    color: var(--text);
    font-size: 1.1em;
}

.home-hero__actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.65em;
    margin-top: 1em;
}

.home-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 42px;
    padding: 0.45em 0.85em;
    border: 1px solid var(--primary);
    border-radius: 6px;
    color: var(--primary);
    font-weight: 700;
    line-height: 1.2;
}

.home-button:hover,
.home-button:focus-visible {
    background: var(--bg-soft);
    text-decoration: none;
}

.home-button--primary {
    background: var(--primary);
    color: var(--primary-contrast);
}

.home-button--primary:hover,
.home-button--primary:focus-visible {
    background: var(--primary-dark);
    color: var(--primary-contrast);
}

.section-lede {
    margin-top: 0;
    color: var(--text-light);
}

.tracks,
.languages,
.book-catalog__track {
    margin: 2em 0;
}

.track-intro,
.track-counts {
    color: var(--text-light);
}

.track-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: 0.85em;
}

.track-card {
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.9em;
    background: var(--bg);
}

.track-card h3 {
    margin: 0 0 0.35em;
    font-size: 1.05em;
    line-height: 1.25;
}

.track-card__description {
    margin: 0;
    color: var(--text-light);
    font-size: 0.92em;
    line-height: 1.45;
}

.track-card__samples {
    margin: 0.65em 0 0;
    padding-left: 1.1em;
    color: var(--text-light);
    font-size: 0.88em;
}

.chapter {
    margin: 2em 0;
}

.chapter h2 {
    color: var(--text);
}

.page-list {
    list-style: none;
    padding: 0;
}

.page-list li {
    padding: 0.5em 0;
    border-bottom: 1px solid var(--border);
}

/* Footer */
footer {
    margin-top: 3em;
    padding-top: 1em;
    border-top: 1px solid var(--border);
    color: var(--text-light);
    font-size: 0.85em;
    text-align: center;
}

/* Responsive */
@media (max-width: 600px) {
    body {
        padding: 14px;
    }

    h1 { font-size: 1.5em; }
    h2 { font-size: 1.2em; }
    .home-hero__lede {
        font-size: 1em;
    }
    .home-button {
        width: 100%;
    }
    .track-grid {
        grid-template-columns: minmax(0, 1fr);
    }
    .pagination {
        flex-direction: column;
    }
    .pagination .toc-link {
        margin: 0;
    }
}

/* The homepage example player (R37, design 15). The viewer's own style comes from /play/simple/simple.css and chapter.css. */
.home-player{margin:1.5em 0 2em}
.home-player__head{display:flex;align-items:baseline;justify-content:space-between;gap:1em;flex-wrap:wrap}
.home-player__head h2{margin:0;border:0;padding:0;font-size:1.35em}
.home-player__hint{color:var(--text-light);font-size:.85em}
.home-player__meta{display:flex;flex-wrap:wrap;align-items:center;gap:.5rem 1rem;margin:.75rem 0 0}
.home-player__title{margin:0;font-weight:600;flex:1 1 14rem;min-width:0;overflow-wrap:anywhere}
.home-player__open{color:#0b57d0;font-weight:600}
.home-player__next{font:inherit;padding:.3rem 1rem}
.home-player__next[hidden]{display:none}
.home-player .sv-gear{font:inherit;padding:.3rem .6rem;line-height:1}
.home-player .sv-edit-btn{display:none}
.home-player .sv-page{max-width:none;padding:0}
.home-player a:focus-visible,.home-player button:focus-visible{outline:3px solid #0b57d0;outline-offset:2px}
@media (prefers-reduced-motion:reduce){.home-player *{scroll-behavior:auto!important;transition:none!important;animation:none!important}}