/* The page around the frame. Its colours, font and corner radius come from style.js, which
   main.js copies into the custom properties below; the sizes here are the page's own. The
   frame itself is drawn on the canvas, entirely from style.js. The picker and the player are
   in controls.css.

   Three modes: the home page (no body class: GitHub Pages, where the user picks the files),
   body.run (pianoize's local preview of a run) and body.capture (the frames of the video). */

:root {
  /* Light text and dark controls on the dark background. */
  color-scheme: dark;
  --muted: color-mix(in srgb, var(--text) 62%, var(--background));
  --raised: color-mix(in srgb, var(--text) 6%, var(--background));
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --gutter: clamp(16px, 4vw, 32px);
  /* Narrow enough on a short window that the stage and the player under it fit one screen. */
  --stage-width: calc((100svh - 140px) * 16 / 9);
}

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.55;
}

a {
  color: inherit;
  text-decoration: underline;
  text-decoration-color: var(--felt);
  text-underline-offset: 3px;
}

a:hover {
  text-decoration-color: currentColor;
}

:focus-visible {
  outline: 2px solid var(--text);
  outline-offset: 2px;
}

code {
  font-family: var(--mono);
  font-size: 0.875em;
}

h1,
h2,
h3,
p,
ol,
dl,
dd,
pre {
  margin: 0;
}

.bar,
main {
  max-width: 1120px;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* The header and the footer. */
.bar {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
}

header.bar {
  padding-block: 20px 0;
}

footer.bar {
  margin-top: 88px;
  padding-bottom: 40px;
  color: var(--muted);
  font-size: 0.9375rem;
}

/* On the text, not the bar, so the rule spans the content and not the gutters. */
footer.bar p {
  flex: 1;
  padding-top: 24px;
  border-top: 1px solid var(--felt);
}

/* The left hand's colour under its half and the right hand's under the other, as the two
   hands sit on the keys. */
.wordmark {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  text-decoration: none;
  padding-bottom: 4px;
  background: linear-gradient(to right, var(--left) 50%, var(--right) 50%) bottom / 100% 3px
    no-repeat;
}

/* Short enough that the keyboard shows on a laptop's first screen. */
.intro {
  padding-block: 36px 28px;
}

.intro h1 {
  font-size: clamp(2rem, 1.25rem + 2.5vw, 3rem);
  font-weight: 500;
  line-height: 1.08;
  letter-spacing: -0.02em;
  text-wrap: balance;
}

.intro p {
  max-width: 62ch;
  margin-top: 14px;
  color: var(--muted);
  font-size: 1.125rem;
}

/* The canvas is the frame, 16:9 from style.js; the stage scales it to the page's width. */
.stage {
  position: relative;
  max-width: var(--stage-width);
  scroll-margin-top: 16px;
  border: 1px solid var(--felt);
  border-radius: var(--radius);
  overflow: hidden;
}

.stage canvas {
  display: block;
  width: 100%;
  height: auto;
}

/* The steps from a recording to the files the stage plays, one row each: the step, then its
   commands. */
.how {
  margin-top: 88px;
}

.how h2 {
  font-size: 1.5rem;
  font-weight: 600;
  line-height: 1.2;
}

.how > p {
  margin-top: 8px;
  color: var(--muted);
}

.how ol {
  margin-top: 28px;
  padding: 0;
  list-style: none;
  counter-reset: step;
}

.how li {
  display: grid;
  grid-template-columns: 2.5rem minmax(0, 2fr) minmax(0, 3fr);
  /* The commands' height goes under the text, not between it and its heading. */
  grid-template-rows: auto 1fr;
  gap: 6px 24px;
  align-items: start;
  padding-block: 24px;
  border-top: 1px solid var(--felt);
  counter-increment: step;
}

.how li::before {
  content: counter(step);
  grid-row: span 2;
  color: var(--muted);
  font-size: 1.75rem;
  font-weight: 300;
  line-height: 1;
}

.how h3 {
  font-size: 1.125rem;
  font-weight: 600;
  line-height: 1.3;
}

.how li p {
  grid-column: 2;
  color: var(--muted);
}

.how pre {
  grid-column: 3;
  grid-row: 1 / span 2;
  padding: 12px 14px;
  overflow-x: auto;
  background: var(--raised);
  border-radius: var(--radius);
  font-size: 0.875rem;
  line-height: 1.6;
}

.how pre code {
  font-size: inherit;
}

@media (max-width: 860px) {
  .how li {
    grid-template-columns: 2.5rem minmax(0, 1fr);
  }

  .how pre {
    grid-column: 2;
    grid-row: auto;
    margin-top: 8px;
  }
}

/* On a phone the picker goes under the stage (controls.css), so the canvas takes the frame. */
@media (max-width: 640px) {
  body:not(.run) .stage {
    overflow: visible;
    border: 0;
  }

  body:not(.run) .stage canvas {
    border: 1px solid var(--felt);
    border-radius: var(--radius);
  }

  /* Wrapped on screen only: a copy still gets each command on one line. */
  .how pre {
    white-space: pre-wrap;
    overflow-wrap: anywhere;
  }
}

/* The local preview: the stage fills the window above the player. */
body.run .home {
  display: none;
}

body.run main {
  display: flex;
  flex-direction: column;
  height: 100vh;
  max-width: none;
  padding: 0;
}

body.run .stage {
  flex: 1 1 0;
  min-height: 0;
  max-width: none;
  border: 0;
  border-radius: 0;
}

body.run .stage canvas {
  height: 100%;
  object-fit: contain;
}

body.run .transport,
body.run .effects {
  max-width: none;
  padding-inline: var(--gutter);
}

/* Capture screenshots the page at the canvas's pixel size, so only the canvas shows, at its
   own size, at the top left. */
body.capture .transport {
  display: none;
}

body.capture .stage canvas {
  width: auto;
  height: auto;
}