:root {
  --night: #0b0b1e;
  --dark-blue: #1d2b53;
  --purple: #7e2553;
  --grey: #5f574f;
  --light: #c2c3c7;
  --white: #fff1e8;
  --orange: #ffa300;
  --yellow: #ffec27;
  --green: #00e436;
  --blue: #29adff;
  --lavender: #83769c;
  --font: "Courier New", Courier, ui-monospace, monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: auto; }

body {
  margin: 0;
  background: var(--night);
  color: var(--white);
  font: bold 16px/1.5 var(--font);
  image-rendering: pixelated;
}

canvas { image-rendering: crisp-edges; image-rendering: pixelated; }

#bg {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

/* ---------- hero ---------- */
.hero {
  min-height: 80vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 48px 16px;
}

.tag { color: var(--blue); letter-spacing: 4px; margin: 0; }

h1 { margin: 16px 0; line-height: 0; }
#title-art { width: min(92vw, 720px); height: auto; }

.lead { max-width: 34em; color: var(--light); margin: 0 0 32px; }

.btn {
  display: inline-block;
  padding: 12px 32px;
  font: inherit;
  font-size: 24px;
  letter-spacing: 4px;
  color: var(--night);
  background: var(--yellow);
  text-decoration: none;
  border: 4px solid var(--white);
  box-shadow: 4px 4px 0 var(--purple), inset -4px -4px 0 var(--orange);
  cursor: pointer;
}
/* Pixel-art play triangle: the font has no glyph for U+25B6. */
.btn .play-icon {
  display: inline-block;
  width: 0;
  height: 0;
  margin-right: 12px;
  border-style: solid;
  border-width: 8px 0 8px 14px;
  border-color: transparent transparent transparent currentColor;
}
.btn:hover, .btn:focus-visible { background: var(--white); outline: 4px solid var(--blue); outline-offset: 4px; }
.btn:active { transform: translate(4px, 4px); box-shadow: none; }

/* ---------- sections ---------- */
main { max-width: 1000px; margin: 0 auto; padding: 0 16px; }

.section { margin: 0 0 64px; }

h2 {
  display: inline-block;
  margin: 0 0 24px;
  padding: 4px 12px;
  font-size: 20px;
  letter-spacing: 4px;
  color: var(--yellow);
  background: var(--night);
  border: 4px solid var(--lavender);
}

.note { color: var(--lavender); margin: 16px 0 0; }

/* The game frame: chunky bevelled border around the integer-scaled canvas. */
.screen {
  display: block;
  width: 100%;
  padding: 12px;
  background: var(--dark-blue);
  border: 4px solid var(--white);
  box-shadow: 8px 8px 0 var(--purple);
  text-align: center;
  line-height: 0;
}
#game {
  display: inline-block;
  box-sizing: content-box; /* the 4px border sits outside the integer-scaled size */
  max-width: none;
  background: var(--night);
  border: 4px solid var(--night);
  cursor: crosshair;
}
#game:focus, #game.focused { outline: none; border-color: var(--green); }
/* Under 320px of room there is no whole-number scale: fill the width instead.
   Content-box sizing keeps the drawing area exactly 16:9 (width minus the two 4px borders). */
#game.fluid { box-sizing: content-box; width: calc(100% - 8px); height: auto; max-width: 100%; aspect-ratio: auto; }

/* Immersive mode (B key): only the game, filling the whole viewport. */
body.immersive { overflow: hidden; }
body.immersive #bg,
body.immersive .hero,
body.immersive .footer,
body.immersive main > .section:not(#demo),
body.immersive #demo > :not(.screen) { display: none; }
body.immersive main { max-width: none; margin: 0; padding: 0; }
body.immersive #demo { margin: 0; }
body.immersive .screen {
  position: fixed;
  inset: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100vw;
  height: 100vh;
  margin: 0;
  padding: 0;
  border: 0;
  box-shadow: none;
  background: var(--night);
}

.cards {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 24px;
}
.card {
  padding: 16px;
  background: var(--night);
  border: 4px solid var(--lavender);
  box-shadow: 6px 6px 0 var(--dark-blue);
}
.card h3 { margin: 0 0 8px; color: var(--orange); font-size: 16px; letter-spacing: 2px; }
.card p { margin: 0; color: var(--light); }

.keys {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0 8px;
  background: transparent;
}
.keys th, .keys td { padding: 8px 12px; background: var(--night); text-align: left; }
.keys th { width: 40%; border: 4px solid var(--lavender); border-right: 0; font-weight: bold; color: var(--white); }
.keys td { border: 4px solid var(--lavender); border-left: 0; color: var(--light); }

kbd {
  display: inline-block;
  min-width: 28px;
  padding: 0 6px;
  text-align: center;
  font: inherit;
  color: var(--night);
  background: var(--light);
  border: 2px solid var(--white);
  box-shadow: 2px 2px 0 var(--grey);
}

.footer {
  padding: 24px 16px 40px;
  text-align: center;
  color: var(--lavender);
  border-top: 4px solid var(--dark-blue);
  background: var(--night);
}
.footer p { margin: 0; }

@media (max-width: 600px) {
  .keys th, .keys td { display: block; width: auto; border: 4px solid var(--lavender); }
  .keys th { border-bottom: 0; }
  .keys td { border-top: 0; margin-bottom: 8px; }
}

.arcade-return{position:relative;z-index:10;display:inline-block;margin:18px 22px;color:#ffb347;font:12px monospace;text-decoration:none}.arcade-return:hover{text-decoration:underline}