:root {
    /* Tol palette */
    --cb-indigo: #332288;
    --cb-green: #117733;
    --cb-teal: #44AA99;
    --cb-sky: #88CCEE;
    --cb-sand: #DDCC77;
    --cb-rose: #CC6677;
    --cb-purple: #AA4499;
    --cb-wine: #882255;

    /* Neutral surfaces */
    --color-bg: #f7f8fa;
    --color-bg-elevated: #ffffff;
    --color-bg-sunken: #f0f2f6;
    --color-ink: #1b1d29;
    --color-ink-muted: #595f72;
    --color-border: #e3e6ee;
    --color-border-strong: #c9cedb;

    /* Semantic tokens */
    --color-accent: var(--cb-indigo);
    --color-accent-soft: color-mix(in srgb, var(--cb-indigo) 8%, white);
    --color-accent-soft-2: color-mix(in srgb, var(--cb-indigo) 14%, white);
    --color-action: var(--cb-indigo);
    --color-link: var(--cb-indigo);
    --color-link-hover: var(--cb-wine);
    --color-active: var(--cb-teal);

    --font-body: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
    --font-display: var(--font-body);
    --font-mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;

    --shadow-sm: 0 1px 2px rgb(27 29 41 / 6%), 0 1px 1px rgb(27 29 41 / 4%);
    --shadow-md: 0 10px 30px rgb(27 29 41 / 12%), 0 2px 6px rgb(27 29 41 / 6%);

    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.5rem;
    --space-6: 2rem;
    --space-7: 3rem;

    --content-max: 84rem;
    --prose-max: 46rem;
    --fold-max: 58rem;
    --plot-umap-w: 600px;
    --plot-umap-h: 500px;
    --plot-violin-w: 130px;
    --keyboard-h: min(200px, 28vw);
    --waveform-max: 1000px;
    --nav-h: 3.25rem;

    --focus-ring: 0 0 0 3px color-mix(in srgb, var(--cb-sky) 55%, transparent);
    --transition-fast: 140ms ease;
}

/* ---------- Reset / base ---------- */

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

html {
    scrollbar-gutter: stable; /* page width must not change when the scrollbar appears (plots measure it at load) */
    scroll-behavior: smooth;
    scroll-padding-top: calc(var(--nav-h) + 1rem);
    -webkit-text-size-adjust: 100%;
    text-size-adjust: 100%;
}

body {
    margin: 0;
    min-height: 100vh;
    min-height: 100dvh;
    color: var(--color-ink);
    font-family: var(--font-body);
    font-size: 1rem;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    background:
        radial-gradient(900px 320px at 50% -80px, color-mix(in srgb, var(--cb-indigo) 7%, transparent), transparent 70%),
        var(--color-bg);
}

img,
svg {
    max-width: 100%;
}

/* Plot canvases use exact pixel sizes: squeezing them would desync mouse and drawing coordinates */
canvas {
    max-width: none;
}

canvas {
    display: block;
    touch-action: none;
}

a {
    color: var(--color-link);
    text-decoration-thickness: 1px;
    text-underline-offset: 0.18em;
    text-decoration-color: color-mix(in srgb, var(--color-link) 40%, transparent);
    transition: color var(--transition-fast), text-decoration-color var(--transition-fast);
}

a:hover {
    color: var(--color-link-hover);
    text-decoration-color: currentColor;
}

:focus-visible {
    outline: 2px solid var(--cb-indigo);
    outline-offset: 2px;
    border-radius: 4px;
}

::selection {
    background: color-mix(in srgb, var(--cb-sky) 60%, white);
}

.skip-link {
    position: absolute;
    left: var(--space-4);
    top: -100px;
    z-index: 2000;
    padding: var(--space-2) var(--space-3);
    background: var(--cb-indigo);
    color: #fff;
    border-radius: var(--radius-sm);
    text-decoration: none;
}

.skip-link:focus {
    top: var(--space-3);
}

/* ---------- Typography ---------- */

h1, h2, h3, h4 {
    font-family: var(--font-display);
    font-weight: 650;
    line-height: 1.2;
    letter-spacing: -0.015em;
    color: var(--color-ink);
    margin: 0 0 var(--space-3);
}

h1 { font-size: clamp(2.1rem, 5vw, 3.4rem); letter-spacing: -0.03em; font-weight: 700; }
h2 { font-size: clamp(1.4rem, 2.6vw, 1.85rem); }
h3 { font-size: 1.15rem; margin-top: var(--space-5); }
h4 {
    font-weight: 600;
    font-size: 0.78rem;
    color: var(--color-ink-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

p { margin: 0 0 var(--space-4); }
ol, ul { margin: 0 0 var(--space-4); padding-left: 1.25rem; }
li { margin-bottom: var(--space-2); }
li::marker { color: var(--color-ink-muted); }

/* ---------- Site chrome ---------- */

.site-header {
    padding: clamp(var(--space-6), 8vw, 5rem) var(--space-5) var(--space-6);
}

.site-header__inner {
    max-width: var(--content-max);
    margin: 0 auto;
}

.site-header__inner > :not(.site-eyebrow):not(.site-title) {
    max-width: var(--prose-max);
}

.site-eyebrow {
    display: inline-block;
    margin: 0 0 var(--space-3);
    padding: 0.25rem 0.7rem;
    font-size: 0.72rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--cb-indigo);
    background: var(--color-accent-soft);
    border: 1px solid var(--color-accent-soft-2);
    border-radius: 999px;
}

.site-title {
    margin-bottom: var(--space-4);
    background: linear-gradient(100deg, var(--cb-indigo) 0%, var(--cb-purple) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: var(--cb-indigo); /* fallback */
}

.site-lede {
    font-size: 1.12rem;
    color: var(--color-ink-muted);
}

.sound-wave {
    display: inline-flex;
    align-items: baseline;
    color: var(--cb-indigo);
    font-weight: 650;
    font-style: italic;
}

.sound-wave__letter {
    display: inline-block;
    will-change: transform;
    animation: sound-letter-wave 1.6s ease-in-out infinite;
    animation-delay: calc(var(--i) * 0.12s);
}

@keyframes sound-letter-wave {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-0.28em); }
}

@media (prefers-reduced-motion: reduce) {
    .sound-wave__letter {
        animation: none;
    }
}

.site-header h3 {
    font-size: 1rem;
}

.section-toc {
    list-style: none;
    padding: 0;
    display: grid;
    gap: var(--space-3);
}

.section-toc li {
    margin: 0;
    padding: var(--space-3) var(--space-4);
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.section-toc a {
    font-weight: 600;
}

/* Sticky nav */

.section-nav {
    position: sticky;
    top: 0;
    z-index: 50;
    display: flex;
    align-items: center;
    gap: var(--space-1);
    min-height: var(--nav-h);
    padding: var(--space-2) max(var(--space-4), calc((100% - var(--content-max)) / 2));
    background: color-mix(in srgb, var(--color-bg-elevated) 82%, transparent);
    border-bottom: 1px solid var(--color-border);
    backdrop-filter: saturate(180%) blur(14px);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
    overflow-x: auto;
    scrollbar-width: none;
}

.section-nav::-webkit-scrollbar { display: none; }

.section-nav__brand {
    margin-right: auto;
    padding-right: var(--space-4);
    font-weight: 700;
    font-size: 0.95rem;
    letter-spacing: -0.01em;
    color: var(--cb-indigo);
    white-space: nowrap;
}

.section-nav a {
    padding: 0.4rem 0.8rem;
    border-radius: 999px;
    color: var(--color-ink-muted);
    font-size: 0.88rem;
    font-weight: 500;
    text-decoration: none;
    white-space: nowrap;
    transition: background var(--transition-fast), color var(--transition-fast);
}

.section-nav a:hover,
.section-nav a:focus-visible {
    background: var(--color-accent-soft);
    color: var(--cb-indigo);
}

main {
    max-width: var(--content-max);
    margin: 0 auto;
    padding: var(--space-5) var(--space-4) var(--space-7);
}

/* ---------- Sections / panels ---------- */

.app-section {
    display: flex;
    flex-direction: column;
    gap: var(--space-5);
    margin-bottom: clamp(var(--space-6), 7vw, 4.5rem);
    padding: 0;
}

.section-header {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding-bottom: var(--space-3);
    border-bottom: 1px solid var(--color-border);
}

.section-header h2 {
    margin: 0;
}

.section-header__index {
    display: inline-grid;
    place-items: center;
    min-width: 2rem;
    height: 2rem;
    padding: 0 0.4rem;
    border-radius: var(--radius-sm);
    background: var(--cb-indigo);
    color: #fff;
    font-family: var(--font-mono);
    font-size: 0.78rem;
    font-weight: 500;
}

.panel {
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-5);
    box-shadow: var(--shadow-sm);
}

.panel__header {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-3);
    margin-bottom: var(--space-4);
}

.panel__title {
    margin: 0;
    font-size: 1.05rem;
}

.prose-block {
    max-width: var(--prose-max);
}

.prose-block a {
    overflow-wrap: anywhere;
}

.prose-block p {
    color: color-mix(in srgb, var(--color-ink) 90%, white);
}

/* ---------- Foldable Science / Music theory briefs ---------- */

.fold-stack {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
    width: 100%;
    max-width: var(--fold-max);
}

.fold {
    margin: 0;
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    overflow: clip;
}

.fold--science {
    border-left: 3px solid var(--cb-teal);
}

.fold--theory {
    border-left: 3px solid var(--cb-sand);
}

.fold__summary {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto;
    align-items: center;
    gap: var(--space-3);
    padding: 0.85rem 1rem;
    cursor: pointer;
    list-style: none;
    user-select: none;
    transition: background var(--transition-fast);
}

.fold__summary::-webkit-details-marker,
.fold__summary::marker {
    display: none;
    content: "";
}

.fold__summary:hover {
    background: var(--color-bg-sunken);
}

.fold__summary:focus-visible {
    outline: none;
    box-shadow: inset var(--focus-ring);
}

.fold__badge {
    display: inline-flex;
    align-items: center;
    padding: 0.2rem 0.55rem;
    border-radius: 999px;
    font-size: 0.68rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    line-height: 1.2;
    white-space: nowrap;
}

.fold--science .fold__badge {
    color: color-mix(in srgb, var(--cb-teal) 75%, black);
    background: color-mix(in srgb, var(--cb-teal) 16%, white);
    border: 1px solid color-mix(in srgb, var(--cb-teal) 35%, white);
}

.fold--theory .fold__badge {
    color: color-mix(in srgb, var(--cb-sand) 55%, black);
    background: color-mix(in srgb, var(--cb-sand) 28%, white);
    border: 1px solid color-mix(in srgb, var(--cb-sand) 55%, white);
}

.fold__title {
    min-width: 0;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--color-ink);
    line-height: 1.35;
}

.fold__chevron {
    width: 0.55rem;
    height: 0.55rem;
    border-right: 2px solid var(--color-ink-muted);
    border-bottom: 2px solid var(--color-ink-muted);
    transform: rotate(45deg);
    transition: transform var(--transition-fast);
    justify-self: end;
    margin-right: 0.15rem;
}

.fold[open] > .fold__summary .fold__chevron {
    transform: rotate(225deg);
    margin-top: 0.2rem;
}

.fold[open] > .fold__summary {
    border-bottom: 1px solid var(--color-border);
    background: color-mix(in srgb, var(--color-bg-sunken) 70%, white);
}

.fold__body {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-4) var(--space-5) var(--space-5);
    max-width: none;
}

.fold__body.panel {
    border: none;
    border-radius: 0;
    box-shadow: none;
    background: transparent;
}

.fold__body > :first-child {
    margin-top: 0;
}

.fold__body > :last-child {
    margin-bottom: 0;
}

#SynthDiv > .fold {
    max-width: none;
}

@media (max-width: 640px) {
    .fold__summary {
        grid-template-columns: minmax(0, 1fr) auto;
        grid-template-areas:
            "badge chevron"
            "title chevron";
        gap: var(--space-1) var(--space-3);
        align-items: start;
    }

    .fold__badge { grid-area: badge; }
    .fold__title { grid-area: title; font-size: 0.9rem; }
    .fold__chevron {
        grid-area: chevron;
        align-self: center;
    }
}

@media (prefers-reduced-motion: reduce) {
    .fold__chevron {
        transition: none;
    }
}

.app-section--methods .methods-grid {
    display: grid;
    gap: var(--space-6);
    max-width: none;
}

.app-section--methods .methods-grid h3:first-child {
    margin-top: 0;
}

@media (min-width: 900px) {
    .app-section--methods .methods-grid {
        grid-template-columns: minmax(0, 1.7fr) minmax(0, 1fr);
        align-items: start;
    }

    .limitations {
        position: sticky;
        top: calc(var(--nav-h) + 1rem);
    }
}

.limitations {
    padding: var(--space-5);
    background: color-mix(in srgb, var(--cb-sand) 16%, white);
    border: 1px solid color-mix(in srgb, var(--cb-sand) 55%, white);
    border-left: 4px solid var(--cb-sand);
    border-radius: var(--radius-md);
}

.limitations h3 {
    margin-top: 0;
    color: var(--cb-wine);
}

/* ---------- Buttons / toolbar ---------- */

.toolbar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--space-2);
}

.btn-group {
    display: inline-flex;
    flex-wrap: wrap;
    padding: 3px;
    gap: 2px;
    background: var(--color-bg-sunken);
    border: 1px solid var(--color-border);
    border-radius: calc(var(--radius-sm) + 3px);
}

.btn-group .btn {
    min-height: 2rem;
    border-color: transparent;
    background: transparent;
    box-shadow: none;
    color: var(--color-ink-muted);
}

.btn-group .btn:hover {
    background: var(--color-bg-elevated);
    color: var(--cb-indigo);
    border-color: transparent;
    box-shadow: var(--shadow-sm);
}

.btn {
    appearance: none;
    -webkit-appearance: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    min-height: 2.5rem;
    padding: 0.45rem 1rem;
    border: 1px solid var(--color-border-strong);
    border-radius: var(--radius-sm);
    background: var(--color-bg-elevated);
    color: var(--color-ink);
    font-family: var(--font-body);
    font-size: 0.88rem;
    font-weight: 600;
    line-height: 1;
    cursor: pointer;
    box-shadow: var(--shadow-sm);
    touch-action: manipulation;
    transition: background var(--transition-fast), border-color var(--transition-fast),
                color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
}

.btn:hover {
    background: var(--color-accent-soft);
    border-color: color-mix(in srgb, var(--cb-indigo) 45%, white);
    color: var(--cb-indigo);
}

.btn:active {
    transform: translateY(1px);
    box-shadow: none;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn--primary {
    background: var(--cb-indigo);
    border-color: var(--cb-indigo);
    color: #fff;
}

.btn--primary:hover {
    background: color-mix(in srgb, var(--cb-indigo) 85%, black);
    border-color: color-mix(in srgb, var(--cb-indigo) 85%, black);
    color: #fff;
}

.btn--ghost {
    background: transparent;
    border-color: transparent;
    box-shadow: none;
    color: var(--color-ink-muted);
}

.btn--ghost:hover {
    background: color-mix(in srgb, var(--cb-rose) 14%, white);
    color: var(--cb-wine);
    border-color: transparent;
}

/* ---------- Synth: science fold ---------- */

.synth-science {
    width: 100%;
    padding: var(--space-1);
}

.synth-science__plot {
    width: 100%;
    max-width: 40rem;
    margin: var(--space-3) 0 var(--space-4);
    padding: var(--space-2);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-bg-elevated);
    box-shadow: var(--shadow-sm);
}

.synth-science__svg {
    display: block;
    width: 100%;
    height: auto;
}

.synth-science__waves {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--space-3);
    margin: var(--space-4) 0;
}

.synth-science__wave {
    display: flex;
    flex-direction: column;
    margin: 0;
    padding: var(--space-3) var(--space-2) var(--space-3);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-bg-elevated);
    box-shadow: var(--shadow-sm);
}

.synth-science__plotCaption {
    margin: 0;
    padding: var(--space-3) var(--space-2) var(--space-3);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-bg-elevated);
    box-shadow: var(--shadow-sm);    
}

.synth-science__wave-plot {
    width: 100%;
    flex: 0 0 auto;
}

.synth-science__wave figcaption {
    flex: 1 1 auto;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: var(--space-4);
    padding: var(--space-1) var(--space-1) var(--space-2);
    min-height: 3.25rem;
    font-size: 0.86rem;
    line-height: 1.45;
    color: var(--color-ink-muted);
    text-align: center;
}

.synth-science__play:hover rect:first-child {
    fill: var(--color-accent-soft);
}

@media (max-width: 720px) {
    .synth-science__waves {
        grid-template-columns: minmax(0, 1fr);
    }
}

/* ---------- Synth: waveform + keyboard ---------- */

#Synth_Waveform_div {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    width: 100%;
}

#Synth_interaction_bar {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: flex-end;
    gap: var(--space-3);
    width: 100%;
}

.synth-waveform-label,
#synth_waveform_name {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.15rem;
    width: 100%;
    margin: 0;
    text-align: center;
}

.synth-waveform-label__eyebrow {
    font-size: 0.68rem;
    font-weight: 650;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-ink-muted);
}

.synth-waveform-label__text {
    display: inline-flex;
    align-items: center;
    max-width: 100%;
    padding: 0.2rem 0.75rem;
    border-radius: 999px;
    background: var(--color-bg-sunken);
    border: 1px solid var(--color-border);
    font-family: var(--font-mono);
    font-size: 0.92rem;
    font-weight: 650;
    color: var(--color-ink-muted);
    line-height: 1.3;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    transition: background var(--transition-fast), border-color var(--transition-fast),
                color var(--transition-fast);
}

.synth-waveform-label.has-gene .synth-waveform-label__text {
    background: color-mix(in srgb, var(--cb-indigo) 8%, white);
    border-color: color-mix(in srgb, var(--cb-indigo) 22%, white);
    color: var(--cb-indigo);
}

#Waveform_Button_div {
    display: flex;
    flex-wrap: wrap;
    flex: 1 1 auto;
    justify-content: flex-end;
    align-items: center;
    gap: var(--space-3);
    min-width: 0;
}

#Synth_Searchbar {
    flex: 1 1 16rem;
    width: auto;
    max-width: 24rem;
}

.canvas-shell {
    width: 100%;
    max-width: var(--waveform-max);
    margin-inline: auto;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-bg-sunken);
    overflow: hidden;
}

#Synth_Waveform {
    width: 100%;
    height: auto;
    aspect-ratio: 5 / 1;
}

.keyboard-shell,
#Synth_Keyboard_div {
    width: 100%;
    max-width: var(--waveform-max);
    margin: var(--space-4) auto 0;
    height: var(--keyboard-h);
    min-height: 120px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-bg-sunken);
    overflow: hidden;
    -webkit-user-select: none;
    user-select: none;
    touch-action: manipulation;
}

.piano-key.pressed {
    fill: var(--cb-teal);
}

.octave-button.pressed rect {
    fill: var(--cb-indigo);
}

.octave-button.pressed polygon {
    fill: #fff;
}

/* ---------- Synth → Jukebox assign strip ---------- */

.synth-to-jukebox,
#pushSound {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-3) var(--space-4);
    width: 100%;
    max-width: var(--waveform-max);
    margin: var(--space-4) auto 0;
    padding: var(--space-3) 2.5rem var(--space-3) var(--space-4);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background:
        linear-gradient(
            110deg,
            color-mix(in srgb, var(--cb-indigo) 5%, white) 0%,
            var(--color-bg-elevated) 55%
        );
    transition: opacity var(--transition-fast), border-color var(--transition-fast),
                background var(--transition-fast);
}

.synth-to-jukebox.is-disabled {
    opacity: 0.72;
    background: var(--color-bg-sunken);
}

.synth-to-jukebox__copy {
    display: flex;
    flex-direction: column;
    gap: 0.15rem;
    min-width: 0;
}

.synth-to-jukebox__title {
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--cb-indigo);
}

.synth-to-jukebox.is-disabled .synth-to-jukebox__title {
    color: var(--color-ink-muted);
}

.synth-to-jukebox__hint {
    margin: 0;
    color: var(--color-ink-muted);
    font-size: 0.9rem;
    line-height: 1.35;
}

.synth-to-jukebox__gene {
    display: inline;
    font-family: var(--font-mono);
    font-size: 0.84em;
    font-weight: 650;
    color: var(--cb-indigo);
}

.synth-to-jukebox__gene.is-empty {
    font-family: var(--font-body);
    font-weight: 500;
    /* font-style: italic; */
    color: var(--color-ink-muted);
}

.synth-to-jukebox__controls {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--space-2);
}

.synth-to-jukebox__field-label {
    font-size: 0.72rem;
    font-weight: 650;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    color: var(--color-ink-muted);
}

.synth-to-jukebox__select {
    appearance: none;
    -webkit-appearance: none;
    min-height: 2.5rem;
    min-width: 9.5rem;
    padding: 0.4rem 2rem 0.4rem 0.75rem;
    border: 1px solid var(--color-border-strong);
    border-radius: var(--radius-sm);
    background:
        var(--color-bg-elevated)
        url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath fill='%33595f72' d='M1.2 1.4h9.6L6 7z'/%3E%3C/svg%3E")
        no-repeat right 0.7rem center / 0.7rem;
    color: var(--color-ink);
    font-family: var(--font-body);
    font-size: 0.88rem;
    font-weight: 600;
    cursor: pointer;
    box-shadow: var(--shadow-sm);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.synth-to-jukebox__select:hover:not(:disabled),
.synth-to-jukebox__select:focus-visible {
    border-color: color-mix(in srgb, var(--cb-indigo) 45%, white);
    outline: none;
    box-shadow: var(--focus-ring);
}

.synth-to-jukebox__select:disabled {
    opacity: 0.55;
    cursor: not-allowed;
    box-shadow: none;
}

.synth-to-jukebox__status {
    min-width: 0;
    font-size: 0.8rem;
    font-weight: 650;
    line-height: 1.2;
}

.synth-to-jukebox__status.is-success {
    color: var(--cb-green);
}

.synth-to-jukebox__status.is-error {
    color: var(--cb-wine);
}

/* ---------- Plots ---------- */

.plot-row,
#Synth_Plots_div {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-4);
    justify-content: center;
    align-items: flex-start;
    width: 100%;
}

.plot-frame {
    position: relative;
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    overflow: auto;
    -webkit-overflow-scrolling: touch;
}

#read_counts,
#fft {
    flex: 1 1 320px;
    max-width: var(--plot-umap-w);
    height: var(--plot-umap-h);
    min-height: 280px;
}

#filter_slider,
.plot-frame--narrow {
    flex: 0 0 auto;
    width: min(100%, calc(var(--plot-violin-w) + 40px));
    min-height: 280px;
}

#Gene_Plots,
.plot-frame--gene {
    display: flex;
    width: 100%;
    max-width: 800px;
    height: auto;
    min-height: 220px;
    margin: var(--space-4) 0;
    justify-content: center;
    align-items: center;
    overflow: auto;
}

/* ---------- MIDI / Arabidopsis Jukebox ---------- */

/* Reserve the closed-handle strip on the right; content stays left-aligned */
#SynthDiv {
    --jukebox-handle-w: 2.75rem;
    --jukebox-gutter: calc(var(--jukebox-handle-w) + var(--space-2));
}

#SynthDiv > :not(.synth-sticky-region) {
    padding-right: var(--jukebox-gutter);
}

.synth-sticky-region {
    display: flex;
    flex-direction: column;
    gap: var(--space-5);
    position: relative;
    /* Absolute dock covers this padding box, so the handle sits in the gutter */
    padding-right: var(--jukebox-gutter);
}

.synth-sticky-dock {
    position: absolute;
    inset: 0;
    z-index: 40;
    pointer-events: none;
}

#midi_container {
    --jukebox-width: min(42rem, calc(100vw - 3.5rem));
    --jukebox-max-h: calc(100vh - var(--nav-h) - 2rem);
    --jukebox-max-h: calc(100dvh - var(--nav-h) - 2rem);

    position: sticky;
    top: calc(var(--nav-h) + 0.5rem);
    display: flex;
    justify-content: flex-end;
    width: 100%;
    height: fit-content;
    max-height: var(--jukebox-max-h);
    pointer-events: none;
}

#midi_panel {
    pointer-events: auto;
    display: flex;
    flex-direction: row;
    align-items: stretch;
    width: var(--jukebox-width);
    max-height: var(--jukebox-max-h);
    transform: translateX(calc(100% - var(--jukebox-handle-w)));
    transition: transform 0.3s ease;
    will-change: transform;
}

#midi_container.is-open #midi_panel {
    transform: translateX(0);
}

#midi_handle {
    flex: 0 0 var(--jukebox-handle-w);
    width: var(--jukebox-handle-w);
    margin: 0;
    padding: 0.75rem 0;
    border: 1px solid var(--color-border-strong);
    border-right: none;
    border-radius: var(--radius-md) 0 0 var(--radius-md);
    background: var(--color-bg-elevated);
    color: var(--color-ink);
    cursor: pointer;
    box-shadow: var(--shadow-sm);
}

#midi_handle:hover,
#midi_handle:focus-visible {
    background: var(--color-accent-soft);
}

#midi_handle:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring), var(--shadow-sm);
}

#midi_handle_text {
    display: inline-block;
    writing-mode: vertical-rl;
    transform: rotate(180deg);
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    white-space: nowrap;
    user-select: none;
}

#midi_content {
    flex: 1 1 auto;
    min-width: 0;
    min-height: 0;
    max-height: var(--jukebox-max-h);
    overflow: auto;
    box-shadow: var(--shadow-md);
}

#midi {
    display: flex;
    flex-direction: column;
    width: 100%;
    border-radius: 0;
    border-left: none;
}

.panel--midi {
    width: 100%;
    padding: var(--space-4);
    background:
        linear-gradient(
            135deg,
            color-mix(in srgb, var(--cb-teal) 6%, white) 0%,
            var(--color-bg-elevated) 42%,
            var(--color-bg-elevated) 100%
        );
    border-color: color-mix(in srgb, var(--cb-teal) 22%, var(--color-border));
}

.midi-header {
    margin-bottom: var(--space-2);
}

.midi-header__titles {
    display: flex;
    flex-direction: column;
    gap: 0.1rem;
    min-width: 0;
}

.midi-header__sub {
    margin: 0;
    max-width: 36rem;
    font-size: 0.8rem;
    line-height: 1.35;
    color: var(--color-ink-muted);
}

.midi-transport {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto;
    align-items: center;
    gap: var(--space-2) var(--space-3);
    margin: 0 0 var(--space-2);
    padding: 0.4rem 0.65rem 0.4rem 0.4rem;
    background: color-mix(in srgb, var(--color-bg-elevated) 82%, var(--cb-teal));
    border: 1px solid color-mix(in srgb, var(--cb-teal) 28%, var(--color-border));
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.midi-transport__play {
    min-width: 3.75rem;
    min-height: 2rem;
    padding-inline: 0.75rem;
    font-size: 0.82rem;
}

.midi-transport__time {
    display: inline-flex;
    align-items: baseline;
    gap: 0.15em;
    min-width: 7.5rem;
    font-family: var(--font-mono);
    font-size: 0.78rem;
    font-variant-numeric: tabular-nums;
    color: var(--color-ink-muted);
    white-space: nowrap;
    user-select: none;
}

#midi_time_display {
    color: var(--color-ink);
    font-weight: 600;
}

/* Scrubber: filled track via --fill (set from midiplayer.js) */
.midi-transport__scrubber {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 1.5rem;
    margin: 0;
    background: transparent;
    cursor: pointer;
    touch-action: none;
}

.midi-transport__scrubber::-webkit-slider-runnable-track {
    height: 6px;
    border-radius: 999px;
    background: linear-gradient(
        to right,
        var(--cb-teal) var(--fill, 0%),
        color-mix(in srgb, var(--color-border-strong) 70%, white) var(--fill, 0%)
    );
}

.midi-transport__scrubber::-moz-range-track {
    height: 6px;
    border-radius: 999px;
    background: color-mix(in srgb, var(--color-border-strong) 70%, white);
}

.midi-transport__scrubber::-moz-range-progress {
    height: 6px;
    border-radius: 999px;
    background: var(--cb-teal);
}

.midi-transport__scrubber::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    margin-top: -5px;
    border: 2px solid #fff;
    border-radius: 50%;
    background: var(--cb-teal);
    box-shadow: 0 1px 3px rgb(27 29 41 / 30%);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.midi-transport__scrubber::-moz-range-thumb {
    width: 12px;
    height: 12px;
    border: 2px solid #fff;
    border-radius: 50%;
    background: var(--cb-teal);
    box-shadow: 0 1px 3px rgb(27 29 41 / 30%);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.midi-transport__scrubber:hover::-webkit-slider-thumb,
.midi-transport__scrubber:focus-visible::-webkit-slider-thumb {
    transform: scale(1.12);
    box-shadow: 0 0 0 3px color-mix(in srgb, var(--cb-teal) 35%, transparent);
}

.midi-transport__scrubber:hover::-moz-range-thumb,
.midi-transport__scrubber:focus-visible::-moz-range-thumb {
    transform: scale(1.12);
    box-shadow: 0 0 0 3px color-mix(in srgb, var(--cb-teal) 35%, transparent);
}

.midi-transport__scrubber:focus-visible {
    outline: none;
}

.midi-hint {
    margin: 0 0 var(--space-2);
    padding: 0.35rem 0.65rem;
    font-size: 0.78rem;
    line-height: 1.35;
    color: var(--color-ink-muted);
    background: var(--color-bg-sunken);
    border: 1px solid var(--color-border);
    border-left: 3px solid var(--cb-sand);
    border-radius: var(--radius-sm);
}

.midi-tracks {
    position: relative;
    display: grid;
    gap: 0.4rem;
    isolation: isolate;
}

.midi-track {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: minmax(11.5rem, 15rem) minmax(0, 1fr);
    gap: 0.5rem 0.75rem;
    align-items: center;
    padding: 0.35rem 0.55rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    background: var(--color-bg-elevated);
    color: var(--cb-indigo);
    transition: border-color var(--transition-fast), background var(--transition-fast),
                box-shadow var(--transition-fast), opacity var(--transition-fast), filter var(--transition-fast);
}

.midi-track:hover {
    border-color: var(--color-border-strong);
}

/* Raise the active track so its gene dropdown paints above siblings.
   (opacity/filter on unloaded tracks create stacking contexts that otherwise trap z-index.) */
.midi-track:focus-within {
    z-index: 40;
    border-color: var(--color-border-strong);
    box-shadow: var(--shadow-sm);
}

/* Unloaded = no wavetable assigned → silent in the audio worklet */
.midi-track.is-unloaded {
    opacity: 0.78;
    filter: grayscale(0.45);
    border-style: dashed;
    border-color: var(--color-border-strong);
    background: var(--color-bg-sunken);
    color: var(--color-ink-muted);
}

.midi-track.is-unloaded:hover,
.midi-track.is-unloaded:focus-within {
    opacity: 0.95;
    filter: grayscale(0.15);
}

.midi-track.is-unloaded .midi-track-display {
    opacity: 0.45;
    border-color: var(--color-border-strong);
}

.midi-track.is-loaded {
    opacity: 1;
    filter: none;
    border-style: solid;
    border-color: color-mix(in srgb, var(--cb-teal) 45%, var(--color-border));
    background:
        linear-gradient(
            90deg,
            color-mix(in srgb, var(--cb-teal) 7%, white) 0,
            var(--color-bg-elevated) 7rem
        );
}

.midi-track__side {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0.2rem;
    min-width: 0;
}

.midi-track__meta {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.3rem 0.35rem;
    min-width: 0;
}

.midi-track__name {
    font-weight: 700;
    font-size: 0.82rem;
    color: var(--color-ink);
    white-space: nowrap;
}

.midi-track__badge {
    flex: 0 0 auto;
    font-size: 0.6rem;
    font-weight: 700;
    letter-spacing: 0.03em;
    text-transform: uppercase;
    padding: 0.1rem 0.4rem;
    border-radius: 999px;
    background: color-mix(in srgb, var(--color-ink-muted) 14%, white);
    color: var(--color-ink-muted);
    border: 1px solid color-mix(in srgb, var(--color-ink-muted) 18%, white);
}

.midi-track.is-loaded .midi-track__badge {
    background: color-mix(in srgb, var(--cb-teal) 16%, white);
    color: var(--cb-green);
    border-color: color-mix(in srgb, var(--cb-teal) 35%, white);
}

.midi-symbol {
    display: grid;
    place-items: center;
    flex: 0 0 auto;
    width: 1.35rem;
    height: 1.35rem;
    border-radius: 6px;
    background: color-mix(in srgb, var(--cb-indigo) 8%, white);
    font-size: 0.78rem;
    line-height: 1;
}

.midi-track.is-unloaded .midi-symbol {
    background: color-mix(in srgb, var(--color-ink-muted) 10%, white);
}

.midi-gene-name {
    display: none;
    margin: 0;
    min-width: 0;
    max-width: 100%;
    width: max-content;
    align-items: center;
    gap: 0.2rem;
    padding: 0.1rem 0.15rem 0.1rem 0.4rem;
    border-radius: 999px;
    background: color-mix(in srgb, var(--cb-indigo) 8%, white);
    border: 1px solid color-mix(in srgb, var(--cb-indigo) 18%, white);
    font-family: var(--font-mono);
    font-size: 0.68rem;
    font-weight: 600;
    color: var(--cb-indigo);
    line-height: 1.2;
}

.midi-track.is-loaded .midi-gene-name {
    display: inline-flex;
    flex: 0 1 auto;
}

.midi-gene-name__id {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.midi-track-remove {
    appearance: none;
    -webkit-appearance: none;
    flex: 0 0 auto;
    display: grid;
    place-items: center;
    width: 1.15rem;
    height: 1.15rem;
    margin: 0;
    padding: 0;
    border: none;
    border-radius: 50%;
    background: color-mix(in srgb, var(--cb-wine) 12%, white);
    color: var(--cb-wine);
    font-size: 0.85rem;
    font-weight: 700;
    line-height: 1;
    cursor: pointer;
    transition: background var(--transition-fast), color var(--transition-fast), transform var(--transition-fast);
}

.midi-track-remove:hover,
.midi-track-remove:focus-visible {
    background: var(--cb-wine);
    color: #fff;
    outline: none;
}

.midi-track-remove:active {
    transform: scale(0.94);
}

.midi-track .gene-search {
    gap: 0;
}

.midi-track .gene-search-label {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.midi-track .gene-search-field input[type="search"] {
    min-height: 1.85rem;
    padding: 0.25rem 0.55rem;
    font-size: 0.78rem;
}

.midi-track .gene-search-results {
    z-index: 50;
    max-height: 200px;
}

.midi-track-display {
    position: relative;
    min-width: 0;
    width: 100%;
    height: 40px;
    overflow: hidden;
    color: inherit;
    border-radius: 6px;
    background:
        repeating-linear-gradient(
            to bottom,
            transparent 0,
            transparent 9px,
            color-mix(in srgb, var(--color-border) 70%, transparent) 9px,
            color-mix(in srgb, var(--color-border) 70%, transparent) 10px
        ),
        color-mix(in srgb, var(--color-bg-sunken) 85%, white);
    border: 1px solid var(--color-border);
}

.midi-track.is-loaded .midi-track-display {
    border-color: color-mix(in srgb, var(--cb-teal) 30%, var(--color-border));
    color: var(--cb-indigo);
}

.midi-track-display svg {
    display: block;
    width: 100%;
    height: 100%;
}

.midi-track-display .midi-playhead {
    color: var(--cb-rose);
}

@media (max-width: 820px) {
    .midi-track {
        grid-template-columns: 1fr;
        gap: 0.35rem;
        align-items: stretch;
    }

    .midi-track-display {
        height: 36px;
    }
}

@media (max-width: 560px) {
    .midi-transport {
        grid-template-columns: auto minmax(0, 1fr);
        grid-template-areas:
            "play time"
            "scrub scrub";
        row-gap: var(--space-2);
        padding: var(--space-2);
    }

    .midi-transport__play { grid-area: play; }
    .midi-transport__time {
        grid-area: time;
        justify-self: end;
        min-width: 0;
    }
    .midi-transport__scrubber { grid-area: scrub; }

    .midi-track {
        padding: 0.4rem 0.5rem;
    }
}

/* ---------- Step sequencer workspace ---------- */
.seq-workspace,
#StepSequencerContainer {
    position: relative;
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    grid-template-areas:
        "main"
        "controls"
        "violin"
        "gp";
    gap: var(--space-4);
    width: 100%;
    align-items: start;
}

@media (min-width: 900px) {
    .seq-workspace,
    #StepSequencerContainer {
        grid-template-columns: minmax(0, 1fr) auto;
        grid-template-areas:
            "main     violin"
            "controls violin"
            "gp       gp";
        align-items: stretch;
    }
}

/* ---------- Step sequencer tutorial chrome ---------- */

#StepSeqTutorialMask {
    position: absolute;
    inset: 0;
    z-index: 999;
    background: rgba(27, 29, 41, 0.45);
    pointer-events: auto;
}

#StepSeqTooltip {
    display: none;
    position: absolute;
    z-index: 1005;
    max-width: min(22rem, calc(100% - 1.5rem));
    padding: var(--space-3) var(--space-4);
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border-strong);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
    pointer-events: auto;
}

#StepSeqTooltip .tutorial-tooltip__body {
    margin: 0 0 var(--space-3);
    font-size: 0.92rem;
    line-height: 1.45;
    color: var(--color-ink);
}

#StepSeqTooltip .tutorial-tooltip__footer {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-2);
}

#StepSeqTooltip .tutorial-tooltip__count {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    color: var(--color-ink-muted);
    font-variant-numeric: tabular-nums;
}

#StepSeqTooltip .tutorial-tooltip__actions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
}

#StepSeqTooltip .tutorial-tooltip__actions .btn {
    min-height: 2rem;
    padding: 0.35rem 0.75rem;
    font-size: 0.82rem;
}

.tutorial-highlight {
    position: absolute;
    z-index: 1004; 
    border: 2px solid var(--cb-sky);
    border-radius: var(--radius-sm);
    box-shadow: 0 0 0 1px rgb(255 255 255 / 70%);
    pointer-events: none;
    box-sizing: border-box;
}

/*
 * unmask  → .tutorial-elevated  (above the dim mask → looks bright)
 * block   → .tutorial-block-interaction on the *unmasked* element
 */
.tutorial-elevated {
    position: relative;
    z-index: 1003;
}

.tutorial-block-interaction,
.tutorial-block-interaction * {
    pointer-events: none;
}

#StepSeqMain,
.plot-frame--seq-main {
    grid-area: main;
    width: 100%;
    min-height: 320px;
    overflow: auto;
}

.panel--seq-controls,
#StepSeqControls {
    grid-area: controls;
    min-width: 0;
    width: 100%;
    padding: var(--space-2) var(--space-3);
}

#StepSeqControlButtons {
    justify-content: center;
}

.panel--filters,
#StepSeqViolin {
    grid-area: violin;
    display: grid;
    grid-template-columns: repeat(3, auto);
    gap: var(--space-1);
    justify-content: center;
    justify-items: center;
    align-content: stretch;
    align-items: stretch;
    align-self: stretch;
    height: 100%;
    padding: var(--space-2);
    width: max-content;
    max-width: 100%;
    /* Reserve column width before the SVGs paint so #StepSeqMain can measure correctly */
    min-width: 20rem;
    box-sizing: border-box;
}

@media (max-width: 899px) {
    .panel--filters,
    #StepSeqViolin {
        width: 100%;
        min-width: 0;
        height: auto;
        grid-template-columns: repeat(3, minmax(0, 1fr));
        align-content: start;
    }
}

@media (max-width: 520px) {
    .panel--filters,
    #StepSeqViolin {
        grid-template-columns: 1fr;
        justify-items: stretch;
    }
}

.violin-slot {
    width: max-content;
    max-width: 100%;
    height: 100%;
    min-height: 0;
    display: flex;
    justify-content: center;
    align-items: stretch;
    overflow: hidden;
}

.violin-slot svg {
    display: block;
    max-height: 100%;
}

.panel--seq-gp,
#StepSeqGPDisplay {
    grid-area: gp;
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-3);
    min-width: 0;
    width: 100%;
    align-items: start;
}

.capsule-toggle {
    display: inline-flex;
    align-items: center;
    padding: 3px;
    gap: 2px;
    width: max-content;
    max-width: 100%;
    background: var(--color-bg-sunken);
    border: 1px solid var(--color-border);
    border-radius: 999px;
}

.capsule-toggle .btn {
    min-height: 2rem;
    padding: 0.35rem 0.95rem;
    border-color: transparent;
    border-radius: 999px;
    background: transparent;
    box-shadow: none;
    color: var(--color-ink-muted);
    font-size: 0.82rem;
}

.capsule-toggle .btn:hover {
    background: var(--color-bg-elevated);
    color: var(--cb-indigo);
    border-color: transparent;
    box-shadow: var(--shadow-sm);
}

.capsule-toggle .btn[aria-pressed="true"] {
    background: var(--cb-indigo);
    border-color: var(--cb-indigo);
    color: #fff;
    box-shadow: var(--shadow-sm);
}

.capsule-toggle .btn[aria-pressed="true"]:hover {
    background: color-mix(in srgb, var(--cb-indigo) 85%, black);
    border-color: color-mix(in srgb, var(--cb-indigo) 85%, black);
    color: #fff;
}

#StepSeqGPPlotandMeta,
.gp-plot-and-meta {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(11.5rem, 15.5rem);
    gap: var(--space-3);
    align-items: stretch;
    min-width: 0;
    width: 100%;
}

#StepSeqGPPlot,
.plot-frame--seq-wave {
    width: 100%;
    min-height: 240px;
    overflow: auto;
}

#StepSeqGPMeta,
.gp-meta {
    display: flex;
    flex-direction: column;
    min-width: 0;
    padding: var(--space-4) var(--space-3);
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.gp-meta__list {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    margin: 0;
    padding: 0;
}

.gp-meta__row {
    display: grid;
    gap: var(--space-1);
    margin: 0;
}

.gp-meta__row dt {
    margin: 0;
    font-size: 0.68rem;
    font-weight: 650;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--color-ink-muted);
}

.gp-meta__unit {
    letter-spacing: 0.02em;
    text-transform: none;
    font-weight: 500;
    opacity: 0.85;
}

.gp-meta__value {
    margin: 0;
    font-size: 0.95rem;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
    color: var(--color-ink);
    line-height: 1.3;
}

.gp-meta__value--mono {
    font-family: var(--font-mono);
    font-size: 0.88rem;
    color: var(--cb-indigo);
}

.gp-meta__period {
    margin: 0;
}

.period-ci {
    position: relative;
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    align-items: start;
    justify-items: center;
    gap: 0;
    min-height: 3.25rem;
    padding: 0.15rem 0 0;
}

.period-ci__rail {
    position: absolute;
    left: 16.666%;
    right: 16.666%;
    top: 0.7rem;
    height: 2px;
    background: color-mix(in srgb, var(--cb-indigo) 45%, var(--color-border-strong));
    border-radius: 999px;
    pointer-events: none;
}

.period-ci__node {
    position: relative;
    z-index: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.35rem;
    width: 100%;
}

.period-ci__dot {
    width: 1.15rem;
    height: 1.15rem;
    border-radius: 50%;
    background: var(--color-bg-elevated);
    border: 2px solid var(--cb-teal);
    box-shadow: 0 0 0 2px var(--color-bg-elevated);
}

.period-ci__node--mid .period-ci__dot {
    width: 1.35rem;
    height: 1.35rem;
    margin-top: -0.1rem;
    background: var(--cb-indigo);
    border-color: var(--cb-indigo);
    box-shadow: 0 0 0 2px var(--color-bg-elevated);
}

.period-ci__val {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
    line-height: 1.15;
    color: var(--color-ink);
    text-align: center;
    white-space: nowrap;
}

.period-ci__node--mid .period-ci__val {
    color: var(--cb-indigo);
    font-size: 0.78rem;
}

.gp-meta.is-empty .period-ci__dot {
    border-color: var(--color-border-strong);
    background: var(--color-bg-sunken);
}

.gp-meta.is-empty .period-ci__node--mid .period-ci__dot {
    background: var(--color-border-strong);
    border-color: var(--color-border-strong);
}

.gp-meta.is-empty .period-ci__rail {
    background: var(--color-border);
}

.gp-meta.is-empty .gp-meta__value,
.gp-meta.is-empty .period-ci__val {
    color: var(--color-ink-muted);
    font-weight: 500;
}

@media (max-width: 720px) {
    #StepSeqGPPlotandMeta,
    .gp-plot-and-meta {
        grid-template-columns: minmax(0, 1fr);
    }
}

/* ---------- D3 axes (all plots) ---------- */

svg .tick line,
svg .domain { stroke: var(--color-border-strong); }
svg .tick text { fill: var(--color-ink-muted); font-size: 11px; font-variant-numeric: tabular-nums; }

/* ---------- Gene search ---------- */

.gene-search {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
    padding: 0;
    min-width: 0;
}

.gene-search-label {
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--color-ink-muted);
}

.gene-search-field {
    position: relative;
    width: 100%;
}

.gene-search-field input[type="search"] {
    width: 100%;
    min-height: 2.5rem;
    padding: 0.55rem 0.8rem;
    border: 1px solid var(--color-border-strong);
    border-radius: var(--radius-sm);
    font-size: 16px; /* prevents iOS zoom-on-focus */
    font-family: var(--font-mono);
    color: var(--color-ink);
    background: var(--color-bg-elevated);
    outline: none;
    -webkit-appearance: none;
    appearance: none;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

@media (min-width: 900px) {
    .gene-search-field input[type="search"] { font-size: 0.88rem; }
}

.gene-search-field input[type="search"]::placeholder {
    color: color-mix(in srgb, var(--color-ink-muted) 65%, white);
}

.gene-search-field input[type="search"]:hover {
    border-color: color-mix(in srgb, var(--cb-indigo) 40%, white);
}

.gene-search-field input[type="search"]:focus {
    border-color: var(--cb-indigo);
    box-shadow: var(--focus-ring);
}

.gene-search-field input[type="search"]::-webkit-search-cancel-button {
    cursor: pointer;
}

.gene-search-results {
    position: absolute;
    z-index: 30;
    top: calc(100% + 6px);
    left: 0;
    right: 0;
    margin: 0;
    padding: var(--space-1);
    list-style: none;
    max-height: 240px;
    overflow-y: auto;
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
}

.gene-search-option {
    padding: 0.5rem 0.7rem;
    border-radius: 6px;
    font-size: 0.84rem;
    font-family: var(--font-mono);
    color: var(--color-ink);
    cursor: pointer;
    line-height: 1.3;
}

.gene-search-option:hover,
.gene-search-option.is-active {
    background: var(--color-accent-soft-2);
    color: var(--cb-indigo);
}

.gene-search-option mark {
    background: color-mix(in srgb, var(--cb-sand) 65%, white);
    color: inherit;
    padding: 0 2px;
    font-weight: 600;
    border-radius: 3px;
}

.gene-search-empty {
    padding: 0.65rem 0.75rem;
    font-size: 0.85rem;
    color: var(--color-ink-muted);
}

/* ---------- Gene tags ---------- */

.gene-tag-tray,
#StepSeqGPSelectedGenes {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
    padding: var(--space-3);
    align-content: flex-start;
    min-height: 3.25rem;
    max-height: 6.5rem;
    overflow-y: auto;
    overflow-x: hidden;
    background: var(--color-bg-sunken);
    border: 1px dashed var(--color-border-strong);
    border-radius: var(--radius-md);
}

.gene-tag {
    display: inline-flex;
    align-items: center;
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border-strong);
    min-height: 1.75rem;
    border-radius: 999px;
    padding: 0.1rem 0.4rem 0.1rem 0.7rem;
    font-size: 0.78rem;
    font-family: var(--font-mono);
    box-shadow: var(--shadow-sm);
    cursor: default;
}

.gene-tag-label {
    cursor: pointer;
    color: var(--cb-indigo);
    line-height: 1.4;
}

.gene-tag-label:hover {
    color: var(--cb-wine);
    text-decoration: underline;
}

.gene-tag-remove {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.1rem;
    line-height: 1;
    padding: 0.2rem 0.35rem;
    border-radius: 50%;
    color: var(--color-ink-muted);
}

.gene-tag-remove:hover {
    color: var(--cb-wine);
    background: color-mix(in srgb, var(--cb-rose) 15%, white);
}

/* ---------- Help ---------- */

.help-panel {
    position: relative;
}

.help-button {
    position: absolute !important;
    top: 0.5rem !important;
    right: 0.5rem !important;
    z-index: 5;
    width: 1.5rem !important;
    height: 1.5rem !important;
    padding: 0 !important;
    border: 1px solid var(--color-border-strong) !important;
    border-radius: 50% !important;
    background: var(--color-bg-elevated) !important;
    color: var(--color-ink-muted) !important;
    font-family: var(--font-body) !important;
    font-size: 0.72rem !important;
    font-weight: 600 !important;
    line-height: 1 !important;
    cursor: pointer !important;
    box-shadow: var(--shadow-sm);
    opacity: 0.75;
    transition: opacity var(--transition-fast), background var(--transition-fast);
}

.help-button:hover,
.help-button:focus-visible {
    opacity: 1;
    background: var(--color-accent-soft-2) !important;
    color: var(--cb-indigo) !important;
    border-color: var(--cb-indigo) !important;
}

#help-popup {
    position: fixed;
    display: none;
    width: min(28rem, calc(100vw - 2rem));
    max-height: min(50vh, 24rem);
    overflow: auto;
    padding: var(--space-4);
    left: 0;
    top: 0;
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    background: color-mix(in srgb, var(--color-bg-elevated) 94%, transparent);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    color: var(--color-ink);
    font-size: 0.9rem;
    line-height: 1.5;
    box-shadow: var(--shadow-md);
    z-index: 1000;
    white-space: pre-line;
}

#help-popup.open {
    display: block;
}

/* ---------- Global volume control (src/globalVolumeControl.js) ---------- */

.volume-control {
    position: fixed;
    right: max(var(--space-4), env(safe-area-inset-right));
    bottom: max(var(--space-4), env(safe-area-inset-bottom));
    z-index: 900;
    display: grid;
    grid-template-columns: auto minmax(5.5rem, 9rem) 3.2rem;
    align-items: center;
    column-gap: var(--space-2);
    padding: 0.35rem 0.75rem 0.35rem 0.4rem;
    background: color-mix(in srgb, var(--color-bg-elevated) 88%, transparent);
    border: 1px solid var(--color-border);
    border-radius: 999px;
    box-shadow: var(--shadow-md);
    backdrop-filter: saturate(180%) blur(14px);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
}

.volume-control__mute {
    display: grid;
    place-items: center;
    width: 2.25rem;
    height: 2.25rem;
    padding: 0;
    border: none;
    border-radius: 50%;
    background: transparent;
    color: var(--cb-indigo);
    cursor: pointer;
    transition: background var(--transition-fast);
}

.volume-control__mute:hover { background: var(--color-accent-soft-2); }
.volume-control.is-muted .volume-control__mute { color: var(--cb-wine); }

.volume-control__value {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    text-align: right;
    color: var(--color-ink-muted);
}

/* Not-yet-unlocked state: a hint bubble above the pill, gently pulsing */
.volume-control__hint {
    position: absolute;
    right: 0;
    bottom: calc(100% + 8px);
    padding: 0.35rem 0.7rem;
    border-radius: var(--radius-sm);
    background: var(--cb-indigo);
    color: #fff;
    font-size: 0.78rem;
    font-weight: 500;
    white-space: nowrap;
    pointer-events: none;
}

.volume-control__hint:empty { display: none; }
.volume-control.is-locked { animation: volume-pulse 2.4s ease-in-out infinite; }

@keyframes volume-pulse {
    0%, 100% { box-shadow: var(--shadow-md); }
    50% { box-shadow: var(--shadow-md), 0 0 0 5px color-mix(in srgb, var(--cb-sky) 55%, transparent); }
}

/* Range slider: filled track via --fill (set from JS) */
.volume-control__slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 1.5rem;
    margin: 0;
    background: transparent;
    cursor: pointer;
    touch-action: pan-y;
}

.volume-control__slider::-webkit-slider-runnable-track {
    height: 4px;
    border-radius: 999px;
    background: linear-gradient(to right, var(--cb-indigo) var(--fill, 80%), var(--color-border-strong) var(--fill, 80%));
}

.volume-control__slider::-moz-range-track {
    height: 4px;
    border-radius: 999px;
    background: var(--color-border-strong);
}

.volume-control__slider::-moz-range-progress {
    height: 4px;
    border-radius: 999px;
    background: var(--cb-indigo);
}

.volume-control__slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    margin-top: -6px;
    border: 2px solid #fff;
    border-radius: 50%;
    background: var(--cb-indigo);
    box-shadow: 0 1px 3px rgb(27 29 41 / 35%);
}

.volume-control__slider::-moz-range-thumb {
    width: 12px;
    height: 12px;
    border: 2px solid #fff;
    border-radius: 50%;
    background: var(--cb-indigo);
    box-shadow: 0 1px 3px rgb(27 29 41 / 35%);
}

.volume-control.is-muted .volume-control__slider { opacity: 0.45; }

@media (max-width: 520px) {
    .volume-control {
        right: 50%;
        transform: translateX(50%);
        grid-template-columns: auto minmax(6rem, 12rem) 3rem;
    }
}

@media print {
    .volume-control { display: none !important; }
}

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

@media (max-width: 800px) {
    .site-header {
        padding-inline: var(--space-4);
    }

    .panel {
        padding: var(--space-4);
    }

    .section-nav__brand {
        display: none;
    }

    .section-nav {
        justify-content: center;
    }

    #Waveform_Button_div {
        justify-content: stretch;
        width: 100%;
    }

    .btn-group {
        width: 100%;
    }

    .btn-group .btn {
        flex: 1 1 auto;
    }

    #Synth_Searchbar {
        max-width: none;
        flex-basis: 100%;
    }

    .synth-to-jukebox,
    #pushSound {
        align-items: stretch;
    }

    .synth-to-jukebox__controls {
        width: 100%;
    }

    .synth-to-jukebox__select {
        flex: 1 1 auto;
        min-width: 0;
    }

    .synth-to-jukebox__status {
        flex: 1 1 100%;
    }
}

@media (max-width: 520px) {
    main {
        padding-inline: var(--space-3);
    }

    #read_counts,
    #fft {
        flex-basis: 100%;
        height: min(80vw, 380px);
    }

    #filter_slider {
        width: 100%;
    }

    .section-nav {
        justify-content: flex-start;
    }
}

@media (hover: none) {
    .help-button { opacity: 1; }
    .btn { min-height: 2.75rem; }
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Print: keep content readable, drop chrome */
@media print {
    .section-nav,
    .skip-link,
    .help-button,
    #help-popup {
        display: none !important;
    }

    body {
        background: #fff;
    }

    .site-title {
        -webkit-text-fill-color: currentColor;
        background: none;
    }

    .panel,
    .plot-frame {
        box-shadow: none;
        break-inside: avoid;
    }
}