/* The matsuokengo.com look, ported from that site's own stylesheet
   (kengomatsuo/kengomatsuo at 8387491, style.css). Rules above the
   "Artosia's own" line are that file's, cut to what this page uses. */

@font-face {
  font-family: "Plus Jakarta Sans"; /* taste-skill-ignore: the brand's typeface */
  src: url("fonts/PlusJakartaSans.woff2") format("woff2");
  font-weight: 500 800;
  font-style: normal;
  font-display: block;
}

@property --card-glow {
  syntax: "<number>";
  inherits: false;
  initial-value: 0;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  cursor: default;
}

a,
button,
[role="button"],
label[for],
summary {
  cursor: pointer;
}

:root {
  --bg: #ffffff;
  --bg-alt: #f7f7f7;
  --surface: #f0f0f0;
  --border: #e6e6e6;
  --text: #111111;
  --muted: #737373;
  /* #737373 reads 4.4:1 on the alternate band; this one reads 5:1 there */
  --muted-alt: #6b6b6b;
  --accent: #008760;
  --radius: 24px;
  --nav-h: 54px;
  --max-w: 960px;
  --pad-x: clamp(1.25rem, 5vw, 2.5rem);
  --glow-border: #e0e0e0;
  --glow-highlight: #b6b6b6;
  --mark: #6a3913;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d0d0d;
    --bg-alt: #141414;
    --surface: #1c1c1c;
    --border: #252525;
    --text: #ebebeb;
    --muted: #808080;
    --muted-alt: #878787;
    --accent: #00a068;
    --glow-border: #3d3d3d;
    --glow-highlight: #a6a6a6;
    --mark: #f0e7d6;
  }
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 1rem);
  background: var(--bg);
  color-scheme: light dark;
}

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

body {
  font-family:
    "Plus Jakarta Sans",
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    "Helvetica Neue",
    Arial,
    sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
}

::selection {
  background: var(--accent);
  color: #ffffff;
}

/* ── Nav ───────────────────────────────────────────── */

nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0 var(--pad-x);
  background: var(--bg);
  border-bottom: 1px solid transparent; /* taste-skill-ignore: the brand's nav line */
  transition: border-bottom-color 0.3s ease;
}

nav.scrolled {
  border-bottom-color: var(--border);
}

.nav-logo {
  font-weight: 700;
  font-size: 0.9375rem;
  color: var(--text);
}

.nav-links {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 1.75rem;
}

.nav-links a {
  font-size: 0.8125rem;
  color: var(--muted);
  transition: color 0.15s;
}

.nav-links a:hover {
  color: var(--text);
}

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

#hero {
  padding: clamp(4.5rem, 12vw, 8rem) var(--pad-x) clamp(3rem, 8vw, 5rem);
}

.hero-inner {
  max-width: var(--max-w);
  margin: 0 auto;
}

#hero h1 {
  font-size: clamp(2.25rem, 6vw, 3.75rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.08;
  margin-bottom: 1rem;
}

.hero-sub {
  font-size: clamp(1rem, 2.5vw, 1.125rem);
  color: var(--muted);
  max-width: 560px;
  margin-bottom: 2rem;
  line-height: 1.55;
}

.hero-links {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  flex-wrap: wrap;
}

.hero-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.5rem 1rem;
  font: inherit;
  font-size: 0.8125rem;
  font-weight: 500;
  border: 1px solid transparent; /* taste-skill-ignore: the brand's glow border */
  border-radius: var(--radius);
  color: var(--text);
  --fill: var(--bg);
  background:
    linear-gradient(var(--fill), var(--fill)) padding-box, /* taste-skill-ignore: a flat fill under the glow */
    conic-gradient( /* taste-skill-ignore: the brand's glow border */
        from calc(var(--card-light-angle, 315deg) - 90deg) at 50% 50%,
        var(--glow-border) 0deg,
        color-mix(
            in srgb,
            rgb(from var(--glow-highlight) r g b / 0.85)
              calc(var(--card-glow) * 100%),
            var(--glow-border)
          )
          90deg,
        var(--glow-border) 180deg,
        var(--glow-border) 240deg,
        color-mix(
            in srgb,
            rgb(from var(--glow-highlight) r g b / 0.85)
              calc(var(--card-glow) * 100%),
            var(--glow-border)
          )
          270deg,
        var(--glow-border) 300deg,
        var(--glow-border) 360deg
      )
      border-box;
  transition:
    color 0.15s,
    opacity 0.15s,
    --card-glow 0.7s ease;
}

.hero-btn:hover {
  color: var(--accent);
}

/* ── Sections ──────────────────────────────────────── */

section {
  padding: clamp(2.5rem, 7vw, 4.5rem) var(--pad-x);
}

.section-inner {
  max-width: var(--max-w);
  margin: 0 auto;
}

.section-title {
  font-size: clamp(1.5rem, 3.2vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.15;
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
}

.shot img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  background: var(--surface);
}

.shot figcaption {
  margin-top: 0.625rem;
  font-size: 0.875rem;
  color: var(--muted);
}

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

footer {
  border-top: 1px solid var(--border); /* taste-skill-ignore: the brand's footer line */
  padding: 1.75rem var(--pad-x);
  background: var(--bg);
}

.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
  font-size: 0.8125rem;
  color: var(--muted);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
}

.footer-links a {
  color: var(--muted);
  transition: color 0.15s;
}

.footer-links a:hover {
  color: var(--text);
}

/* ── Appear animations ─────────────────────────────── */

/* Hidden only once the page's own script has said it is running (html.js),
   and shown regardless four seconds later (html.late), so a script that
   never arrives or a tab that never paints cannot leave the page blank. */
.js .appear {
  opacity: 0;
  transform: translateY(var(--appear-y, 18px));
  transition:
    opacity 0.9s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.9s cubic-bezier(0.16, 1, 0.3, 1),
    border-bottom-color 0.3s ease;
  transition-delay: var(--appear-delay, 0s);
}

.js .appear.visible,
.js.late .appear {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  .js .appear {
    transition: opacity 0.3s ease;
    transform: none;
  }
}

/* ── Artosia's own ─────────────────────────────────── */

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 6px;
}

.hero-btn:focus-visible {
  border-radius: var(--radius);
}

.nav-logo {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  letter-spacing: -0.01em;
}

.nav-logo svg {
  width: 1.375rem;
  height: auto;
  fill: var(--mark);
}

.nav-links .hero-btn {
  color: var(--text);
}

.nav-links .hero-btn:hover {
  color: var(--accent);
}

@media (max-width: 640px) {
  .nav-links {
    gap: 1rem;
  }
  .nav-links .nav-far {
    display: none;
  }
}

/* The download is the one filled control: ink on the page colour, never the accent. */
.hero-btn--primary {
  --fill: var(--text);
  padding: 0.75rem 1.375rem;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--bg);
}

.hero-btn--primary:hover {
  color: var(--bg);
  opacity: 0.85;
}

.hero-btn--quiet {
  padding: 0.75rem 1.125rem;
  font-size: 0.875rem;
}

.release-note {
  margin-top: 0.875rem;
  font-size: 0.8125rem;
  color: var(--muted);
}

.zip-note {
  margin-top: 1.5rem;
  font-size: 0.9375rem;
  max-width: 34rem;
}

.zip-note a {
  font-weight: 500;
  color: var(--accent);
  white-space: nowrap;
  transition: opacity 0.15s;
}

.zip-note a:hover {
  opacity: 0.7;
}

.band-alt {
  background: var(--bg-alt);
  --muted: var(--muted-alt);
}

/* The window on the page: real captures of the operator, stepped by the page's own Prev and Next. */
.stage {
  max-width: 1200px;
  margin: clamp(2.5rem, 7vw, 4rem) auto 0;
}

.stage-frames {
  display: grid;
  border-radius: var(--radius);
  background: var(--surface);
  overflow: hidden;
  aspect-ratio: 16 / 10;
}

.stage-frames picture {
  grid-area: 1 / 1;
  opacity: 0;
  transition: opacity 0.28s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.stage-frames picture.current {
  opacity: 1;
}

.stage-frames img {
  display: block;
  width: 100%;
  height: auto;
}

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

.stage-bar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.625rem 1rem;
  margin-top: 0.875rem;
}

.stage-keys {
  display: flex;
  gap: 0.5rem;
}

.stage-keys .hero-btn {
  min-width: 4.25rem;
  min-height: 2.75rem;
  justify-content: center;
  font-size: 0.875rem;
  font-weight: 600;
}

.stage-keys .hero-btn[disabled] {
  color: var(--muted);
  opacity: 0.55;
  cursor: default;
}

.stage-count {
  font-size: 0.8125rem;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  min-width: 3.5rem;
}

.stage-caption {
  flex: 1 1 16rem;
  font-size: 0.875rem;
  color: var(--muted);
}

/* What it does: a sentence beside the screen that proves it. */
.features {
  display: flex;
  flex-direction: column;
  gap: clamp(2.5rem, 7vw, 4.5rem);
}

.feature {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  align-items: center;
  column-gap: clamp(1.5rem, 4vw, 3rem);
  row-gap: 1.25rem;
}

.feature-words {
  grid-column: 1 / span 5;
}

.feature .shot {
  grid-column: 6 / span 7;
}

.feature--flip .feature-words {
  grid-column: 8 / span 5;
  grid-row: 1;
}

.feature--flip .shot {
  grid-column: 1 / span 7;
  grid-row: 1;
}

.feature--wide .feature-words,
.feature--wide .shot {
  grid-column: 1 / -1;
}

.feature-title {
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.3;
  margin-bottom: 0.5rem;
}

.feature-text {
  font-size: 1.0625rem;
  line-height: 1.55;
  max-width: 34rem;
}

@media (max-width: 760px) {
  .feature-words,
  .feature .shot,
  .feature--flip .feature-words,
  .feature--flip .shot {
    grid-column: 1 / -1;
    grid-row: auto;
  }
}

/* Start: three plain steps and the same download. */
.steps {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.5rem clamp(1.5rem, 4vw, 3rem);
  counter-reset: step;
  margin-bottom: 2.25rem;
}

.steps li {
  counter-increment: step;
}

.steps .feature-title::before {
  content: counter(step) ". ";
  color: var(--muted);
}

@media (max-width: 760px) {
  .steps {
    grid-template-columns: 1fr;
  }
}

/* Good to know: a term and its one line. */
.facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.5rem clamp(1.5rem, 4vw, 3rem);
}

.facts dt {
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 0.25rem;
}

.facts dd {
  font-size: 1.0625rem;
  line-height: 1.55;
  max-width: 30rem;
}

@media (max-width: 640px) {
  .facts {
    grid-template-columns: 1fr;
  }
}