/*
 * SubTrack marketing site.
 *
 * The palette is lifted from the app icon: the indigo-to-magenta gradient
 * behind the clapperboard, and the gold its glyphs are outlined in. One family
 * sets the whole page — Archivo's width axis separates display from text, so
 * the width jump itself carries the typography.
 */

@font-face {
  font-family: "Archivo";
  src: url("assets/fonts/archivo.woff2") format("woff2-variations");
  font-weight: 400 800;
  font-stretch: 62.5% 125%;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Plex Mono";
  src: url("assets/fonts/plex-mono-400.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Plex Mono";
  src: url("assets/fonts/plex-mono-500.woff2") format("woff2");
  font-weight: 500;
  font-style: normal;
  font-display: swap;
}

:root {
  --paper: #edebf0;
  --paper-raised: #f9f8fa;
  --paper-deep: #e3e0e9;
  --ink: #17131f;
  --ink-soft: #5d5570;
  --rule: #d8d3e0;

  /* The ledger panel, straight off the icon's upper corner. */
  --chassis-top: #271c49;
  --chassis-bottom: #1a1230;
  --chassis-line: #372a5e;
  --chassis-ink: #ece8f4;
  --chassis-ink-dim: #8d84ab;

  --magenta: #b23566;
  --magenta-hover: #98284f;
  --on-magenta: #ffffff;
  --gold: #dfad55;

  --page-width: 1080px;
  --gutter: 1.5rem;
  --measure: 60ch;
  --radius: 6px;
  --radius-panel: 12px;

  --font: "Archivo", -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;

  /* Display type is the same family opened up and pushed heavy. */
  --width-display: 116%;
  --width-text: 100%;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #131020;
    --paper-raised: #1c1830;
    --paper-deep: #0e0b1a;
    --ink: #f1eef8;
    --ink-soft: #a29ab9;
    --rule: #2c2544;

    --chassis-top: #2b1f52;
    --chassis-bottom: #1c1334;
    --chassis-line: #3d2f68;

    --magenta: #d95c8b;
    --magenta-hover: #e87ba3;
    --on-magenta: #16101f;
    --gold: #e8bc63;
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  margin: 0;
  font-family: var(--font);
  font-stretch: var(--width-text);
  font-size: 17px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1,
h2 {
  font-stretch: var(--width-display);
  font-weight: 800;
  line-height: 1.03;
  letter-spacing: -0.035em;
  text-wrap: balance;
}

h1 {
  font-size: clamp(2.1rem, 4.8vw, 3.375rem);
  margin: 0 0 1.25rem;
}

h2 {
  font-size: clamp(1.75rem, 3.4vw, 2.5rem);
  margin: 0 0 1.75rem;
}

h3 {
  font-stretch: 106%;
  font-weight: 700;
  font-size: 1.0625rem;
  line-height: 1.25;
  letter-spacing: -0.015em;
  margin: 0 0 0.4em;
}

p {
  margin: 0 0 1rem;
}

a {
  color: var(--magenta);
  text-underline-offset: 0.18em;
  text-decoration-thickness: 1px;
}

a:hover {
  color: var(--magenta-hover);
}

:focus-visible {
  outline: 2px solid var(--magenta);
  outline-offset: 3px;
  border-radius: 2px;
}

code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: color-mix(in srgb, var(--ink) 8%, transparent);
  border-radius: 3px;
  padding: 0.12em 0.36em;
}

strong {
  font-weight: 700;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

.skip-link {
  position: absolute;
  left: 0.5rem;
  top: -3rem;
  z-index: 20;
  padding: 0.5rem 1rem;
  background: var(--paper-raised);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  transition: top 120ms ease;
}

.skip-link:focus {
  top: 0.5rem;
}

/* ─────────────────────────────  Layout  ───────────────────────────── */

/*
 * The section owns the content column, so every child shares one left edge
 * whether or not it sets its own margins.
 */
main > section,
.site-header,
.footer-inner {
  padding-inline: max(var(--gutter), calc((100% - var(--page-width)) / 2));
}

main > section {
  padding-block: 5.5rem;

  /* Clears the sticky header, so an anchored heading isn't hidden behind it. */
  scroll-margin-top: 3.5rem;
}

/* Exceeds the hero's own offset, so the wordmark returns to the very top. */
#top {
  scroll-margin-top: 12rem;
}

/* A hairline is the only separator between sections; there are no colour bands. */
main > section:not(.hero):not(.showcase):not(.doc) {
  border-top: 1px solid var(--rule);
}

/* The app captures are light windows, so they get a deeper ground to sit on. */
.tinted {
  background: var(--paper-deep);
}

.section-lede {
  max-width: var(--measure);
  margin: -0.75rem 0 2.5rem;
  color: var(--ink-soft);
}

/* The mono label repeats the section's name in the nav, so the rule says where you are. */
.section-mark,
.eyebrow,
.step-label {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 0.6875rem;
  letter-spacing: 0.19em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.section-mark {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin: 0 0 1.5rem;
}

.section-mark::before {
  content: "";
  width: 0.4rem;
  height: 0.4rem;
  background: var(--magenta);
}

/* ─────────────────────────────  Header  ───────────────────────────── */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 2rem;
  padding-block: 0.7rem;
  background: color-mix(in srgb, var(--paper) 82%, transparent);
  backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--rule);
}

.wordmark {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  font-stretch: 116%;
  font-weight: 700;
  font-size: 1.0625rem;
  letter-spacing: -0.02em;
  color: var(--ink);
  text-decoration: none;
}

.wordmark img {
  border-radius: 6px;
}

.site-header nav {
  display: flex;
  gap: 1.5rem;
  margin-right: auto;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.site-header nav a {
  color: var(--ink-soft);
  text-decoration: none;
  padding-block: 0.35rem;
  border-bottom: 1px solid transparent;
  transition: color 120ms ease, border-color 120ms ease;
}

.site-header nav a:hover {
  color: var(--ink);
  border-bottom-color: var(--magenta);
}

/* ─────────────────────────────  Buttons  ──────────────────────────── */

.button {
  display: inline-block;
  padding: 0.65rem 1.35rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  background: var(--paper-raised);
  color: var(--ink);
  font-weight: 600;
  font-size: 0.9375rem;
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 120ms ease, border-color 120ms ease, color 120ms ease;
}

.button:hover {
  border-color: var(--magenta);
  color: var(--ink);
}

.button-primary {
  background: var(--magenta);
  border-color: var(--magenta);
  color: var(--on-magenta);
}

.button-primary:hover {
  background: var(--magenta-hover);
  border-color: var(--magenta-hover);
  color: var(--on-magenta);
}

.button-small {
  padding: 0.35rem 0.9rem;
  font-size: 0.875rem;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 0.85rem;
}

/* ──────────────────────────────  Hero  ────────────────────────────── */

.hero {
  padding-top: 4rem;
  padding-bottom: 3rem;
}

.hero-icon {
  width: 88px;
  height: 88px;
  margin-bottom: 1.75rem;
}

.eyebrow {
  margin: 0 0 1.1rem;
}

.lede {
  max-width: 56ch;
  margin-bottom: 2rem;
  font-size: 1.1875rem;
  line-height: 1.5;
  color: var(--ink-soft);
}

.fine-print {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--ink-soft);
}

/* ─────────────────────────────  Ledger  ───────────────────────────── */

/*
 * The signature element: one file's track list, with the dropped tracks struck
 * out. The markup carries the finished state, so no-JS and reduced-motion get
 * the answer; ledger.js replays the subtraction for everyone else.
 */
.ledger {
  margin: 3.5rem 0 0;
  padding: 1.5rem 1.75rem 1.75rem;
  border-radius: var(--radius-panel);
  background: linear-gradient(158deg, var(--chassis-top), var(--chassis-bottom) 62%, #2a1540);
  color: var(--chassis-ink);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.9;
  box-shadow: 0 18px 40px -22px rgb(23 8 46 / 55%);
}

/* The drop shadow does no work against a dark page, so the edge is drawn. */
@media (prefers-color-scheme: dark) {
  .ledger {
    border: 1px solid var(--chassis-line);
    box-shadow: none;
  }
}

.ledger-io {
  display: grid;
  grid-template-columns: 4ch 1fr auto auto;
  gap: 0 1.25rem;
  align-items: baseline;
}

.ledger-dir {
  color: var(--chassis-ink-dim);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 500;
}

.ledger-file {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.ledger-count {
  color: var(--chassis-ink-dim);
}

.ledger-size {
  font-weight: 500;
  font-variant-numeric: tabular-nums;
  min-width: 7ch;
  text-align: right;
}

.ledger-out {
  border-top: 1px solid var(--chassis-line);
  padding-top: 0.9rem;
  margin-top: 0.9rem;
}

.tracks {
  list-style: none;
  margin: 0.9rem 0;
  padding: 0.9rem 0;
  border-block: 1px solid var(--chassis-line);
}

.track {
  position: relative;
  display: grid;
  grid-template-columns: 5.5ch 9.5ch 4.5ch 8ch 1fr 5ch;
  gap: 0 0.75rem;
}

.track-keep .t-verdict {
  color: var(--gold);
}

.track-drop {
  color: var(--chassis-ink-dim);
}

/*
 * The strike is a pseudo-element so it can be drawn on, rather than toggled. It
 * stops short of the verdict column: the verdict annotates the line, the way a
 * proofreader's mark sits in the margin of the text it cancels.
 */
.track-drop::after {
  content: "";
  position: absolute;
  left: 0;
  right: calc(5ch + 0.75rem);
  top: 50%;
  height: 1px;
  background: currentColor;
  opacity: 0.55;
  transform-origin: left center;
}

.t-idx,
.t-detail {
  color: var(--chassis-ink-dim);
}

.track-drop .t-idx,
.track-drop .t-detail {
  color: inherit;
}

.t-verdict {
  text-align: right;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.6875rem;
}

.ledger figcaption {
  margin-top: 1.5rem;
  max-width: 62ch;
  font-family: var(--font);
  font-stretch: var(--width-text);
  font-size: 0.9375rem;
  line-height: 1.55;
  color: var(--chassis-ink-dim);
}

/* The output size is the payoff, so it carries the same gold as the kept rows. */
.ledger-out .ledger-size {
  color: var(--gold);
}

/* Replay: rows dim and strike in sequence, oldest first. */
@media (prefers-reduced-motion: no-preference) {
  .ledger.is-playing .track-drop {
    animation: track-dim 240ms ease-out both;
    animation-delay: calc(var(--i) * 55ms);
  }

  .ledger.is-playing .track-drop::after {
    animation: track-strike 240ms ease-out both;
    animation-delay: calc(var(--i) * 55ms);
  }
}

@keyframes track-dim {
  from {
    color: var(--chassis-ink);
  }
}

@keyframes track-strike {
  from {
    transform: scaleX(0);
  }
}

/* ────────────────────────────  Showcase  ──────────────────────────── */

.showcase {
  padding-block: 0 5.5rem;
}

.shot {
  margin: 0;
}

/* The captures carry their own window shadow, so they need no frame. */
.shot img {
  display: block;
  width: 100%;
  height: auto;
}

.shot figcaption {
  margin-top: 0.9rem;
  font-size: 0.9375rem;
  line-height: 1.5;
  color: var(--ink-soft);
}

.shot-row {
  display: grid;
  gap: 2.5rem;
  margin-top: 2.5rem;
}

/*
 * The columns are sized to the captures' aspect ratios, so both fill their
 * column at one shared height and the captions start on the same line.
 */
@media (min-width: 861px) {
  .shot-row {
    grid-template-columns: 1.336fr 1fr;
  }
}

/* ────────────────────────────  Steps  ─────────────────────────────── */

/* A signal path: one rule across all three stages, ticked at each. */
.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 2.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.steps li {
  border-top: 1px solid var(--ink);
  padding-top: 1rem;
}

.step-label {
  position: relative;
  margin: 0 0 1.25rem;
  color: var(--magenta);
}

.step-label::before {
  content: "";
  position: absolute;
  top: -1rem;
  left: 0;
  width: 1px;
  height: 0.5rem;
  background: var(--ink);
}

.steps p:last-child {
  margin: 0;
  color: var(--ink-soft);
}

/* ───────────────────────────  Features  ───────────────────────────── */

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2.25rem 2.5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.feature-grid li {
  border-top: 1px solid var(--rule);
  padding-top: 1rem;
}

.feature-grid p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.55;
  color: var(--ink-soft);
}

/* ───────────────────────────  Editions  ───────────────────────────── */

.editions {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
}

/*
 * Both cards run the same seven rows in the same order, so the difference
 * between the builds is legible without either being framed as the leftovers.
 */
.edition {
  display: flex;
  flex-direction: column;
  padding: 2rem;
  background: var(--paper-raised);
  border: 1px solid var(--rule);
  border-radius: var(--radius-panel);
}

.edition h3 {
  font-stretch: 112%;
  font-size: 1.375rem;
  margin-bottom: 0.25rem;
}

.edition-note {
  color: var(--ink-soft);
  font-size: 0.9375rem;
  margin-bottom: 1.5rem;
}

.edition .button {
  margin-top: auto;
  align-self: flex-start;
}

.edition .fine-print {
  margin: 0 0 1.25rem;
}

.spec {
  margin: 0 0 1.5rem;
  padding: 0;
  list-style: none;
  font-size: 0.9375rem;
}

.spec li {
  display: grid;
  grid-template-columns: 1.6rem 1fr;
  align-items: baseline;
  padding-block: 0.4rem;
  border-top: 1px solid var(--rule);
}

.spec li:first-child {
  border-top: 0;
}

.spec .off {
  color: var(--ink-soft);
}

.mark {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
}

.mark.yes {
  color: var(--magenta);
}

.mark.no {
  color: var(--ink-soft);
  opacity: 0.6;
}

/* ─────────────────────────────  FAQ  ──────────────────────────────── */

.faq {
  max-width: var(--measure);
  margin: 0;
}

.faq dt {
  font-stretch: 106%;
  font-weight: 700;
  letter-spacing: -0.015em;
  border-top: 1px solid var(--rule);
  padding-top: 1.25rem;
  margin-top: 1.75rem;
}

.faq dt:first-of-type {
  border-top: 0;
  padding-top: 0;
  margin-top: 0;
}

.faq dd {
  margin: 0.4rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--ink-soft);
}

/* ─────────────────────  Long-form document page  ──────────────────── */

.doc h1 {
  font-size: clamp(2rem, 4vw, 2.75rem);
  margin-bottom: 0.5rem;
}

.doc-date {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-soft);
  margin-bottom: 2.5rem;
}

/* A plain-language précis of the sections below; the policy itself governs. */
.doc-summary {
  max-width: var(--measure);
  margin-bottom: 3.5rem;
  padding: 1.75rem 2rem;
  background: var(--paper-raised);
  border: 1px solid var(--rule);
  border-radius: var(--radius-panel);
}

.doc-summary h2 {
  font-stretch: 108%;
  font-size: 1.0625rem;
  margin-bottom: 1rem;
}

.doc-summary ul {
  margin: 0 0 1rem;
  padding: 0;
  list-style: none;
  font-size: 0.9375rem;
}

.doc-summary li {
  padding-left: 1rem;
  margin-bottom: 0.6rem;
  text-indent: -1rem;
  color: var(--ink-soft);
}

.doc-summary li::before {
  content: "";
  display: inline-block;
  width: 0.3rem;
  height: 0.3rem;
  margin-right: 0.7rem;
  vertical-align: 0.2em;
  text-indent: 0;
  background: var(--magenta);
}

.doc-summary > p:last-child {
  margin: 0;
  font-size: 0.875rem;
  color: var(--ink-soft);
}

.doc-body {
  max-width: var(--measure);
}

.doc-body h2 {
  font-stretch: 108%;
  text-wrap: pretty;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  border-top: 1px solid var(--rule);
  padding-top: 1.5rem;
  margin: 3rem 0 1rem;
}

.doc-body h3 {
  margin: 2rem 0 0.5rem;
}

.doc-body p {
  color: var(--ink-soft);
  font-size: 0.9375rem;
  line-height: 1.65;
}

/* ────────────────────────────  Footer  ────────────────────────────── */

.site-footer {
  border-top: 1px solid var(--rule);
  background: var(--paper-deep);
  font-size: 0.8125rem;
  color: var(--ink-soft);
}

.footer-inner {
  padding-block: 3rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.footer-links a {
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.footer-links a:hover {
  border-bottom-color: var(--magenta);
}

.attribution {
  max-width: var(--measure);
  margin-top: 1.75rem;
  line-height: 1.55;
}

.copyright {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

/* ───────────────────────────  Narrow  ─────────────────────────────── */

@media (max-width: 860px) {
  .site-header nav {
    display: none;
  }

  .site-header {
    gap: 1rem;
  }
}

@media (max-width: 640px) {
  main > section,
  .site-header,
  .footer-inner {
    padding-inline: 1.25rem;
  }

  main > section {
    padding-block: 3.5rem;
  }

  .hero {
    padding-top: 2.5rem;
  }

  .showcase {
    padding-block: 0 3.5rem;
  }

  .ledger {
    padding: 1.1rem 1.1rem 1.25rem;
    font-size: 0.6875rem;
    line-height: 1.85;
  }

  /* Codec and channel layout are the first things to go when space runs out. */
  .track {
    grid-template-columns: 5.5ch 9.5ch 4.5ch 1fr 5ch;
  }

  .t-detail {
    display: none;
  }

  /* The track counts carry the argument; the filename is the decorative part. */
  .ledger-io {
    grid-template-columns: 4ch auto 1fr;
  }

  .ledger-file {
    display: none;
  }
}