:root {
  --bg: oklch(0.97 0.008 85);
  --ink: oklch(0.24 0.01 85);
  --ink-muted: oklch(0.55 0.012 85);
  --rule: oklch(0.86 0.01 85);
  --valid: oklch(0.56 0.15 152);
  --invalid: oklch(0.5 0.17 27);
  --flood-ink: oklch(0.985 0.005 85);
  --flood-ink-soft: oklch(0.985 0.005 85 / 0.78);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: oklch(0.19 0.008 85);
    --ink: oklch(0.93 0.006 85);
    --ink-muted: oklch(0.62 0.01 85);
    --rule: oklch(0.32 0.01 85);
  }
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html, body { height: 100%; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  transition: background-color 200ms cubic-bezier(0.25, 1, 0.5, 1);
  -webkit-tap-highlight-color: transparent;
  padding: env(safe-area-inset-top) env(safe-area-inset-right)
           env(safe-area-inset-bottom) env(safe-area-inset-left);
}
body.valid   { background: var(--valid);   transition-duration: 120ms; }
body.invalid { background: var(--invalid); transition-duration: 120ms; }

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

main {
  height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
}

form {
  width: 100%;
  /* sit above true centre: leave room for the keyboard and the definition */
  transform: translateY(-12dvh);
  padding: 0 1.25rem;
}

.word-row {
  position: relative;
}

#word {
  width: 100%;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--ink);
  font: 700 var(--word-size, 3rem) -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  text-align: center;
  caret-color: var(--ink-muted);
  border-bottom: 1px solid var(--rule);
  padding: 0.25rem 2.25rem 0.4rem;
  border-radius: 0;
}
#word:disabled { opacity: 0.4; }

#word::placeholder {
  color: var(--ink-muted);
  opacity: 0.55;
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.14em;
}

body.valid #word, body.invalid #word {
  color: var(--flood-ink);
  border-bottom-color: transparent;
  caret-color: transparent;
}

#clear {
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  border: 0;
  background: transparent;
  color: var(--ink-muted);
  font-size: 1.1rem;
  line-height: 1;
  padding: 0.75rem;
  cursor: pointer;
}
body.valid #clear, body.invalid #clear { color: var(--flood-ink-soft); }

#verdict {
  text-align: center;
  visibility: hidden;
  min-height: 9rem;
  padding-top: 1.4rem;
}
body.valid #verdict, body.invalid #verdict { visibility: visible; }

.rule {
  width: 3.5rem;
  height: 1px;
  margin: 0 auto 1.1rem;
  background: var(--flood-ink-soft);
}

#ruling {
  color: var(--flood-ink);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.14em;
}

#definition {
  color: var(--flood-ink-soft);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.125rem;
  line-height: 1.5;
  max-width: 28ch;
  margin: 0.7rem auto 0;
}

#boot {
  text-align: center;
  color: var(--ink-muted);
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  padding-top: 1.4rem;
}