/* Rhythumb — the site, in the app's own light.
   Palette lifted verbatim from PlaySurface.swift so the page and the thing it
   describes are recognisably one object. */

:root {
  --ground-high: #101A32;
  --ground-mid:  #080C16;
  --ground-low:  #05070C;
  --left-core:   #4A90D9;
  --left-glow:   #CFE4FF;
  --right-core:  #DDA05A;
  --right-glow:  #FFE9C9;
  --star:        #DCE4FF;
  --ink:         #E8E6E1;
  --ink-soft:    #9BA3B4;
  --rule:        #1E2637;
  --measure: 34rem;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(120% 80% at 50% 0%, var(--ground-high) 0%, var(--ground-mid) 45%, var(--ground-low) 100%),
    var(--ground-low);
  background-attachment: fixed;
  color: var(--ink);
  font: 400 17px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: 46rem; margin: 0 auto; padding: 0 1.5rem 5rem; }
.prose { max-width: var(--measure); }

/* --- the two bodies, as on the play surface ------------------------------ */

.sky { position: relative; height: 15rem; margin: 3rem 0 2.5rem; }

.body {
  position: absolute;
  border-radius: 50%;
  animation: breathe 11s ease-in-out infinite;
}
.body.left {
  width: 9.5rem; height: 9.5rem; left: 12%; top: 8%;
  background: radial-gradient(circle at 37% 33%, var(--left-glow) 0%, var(--left-core) 38%, rgba(74,144,217,0.06) 100%);
  box-shadow: 0 0 6rem 1.5rem rgba(74,144,217,0.22);
}
.body.right {
  width: 8.5rem; height: 8.5rem; left: 42%; top: 42%;
  background: radial-gradient(circle at 37% 33%, var(--right-glow) 0%, var(--right-core) 38%, rgba(221,160,90,0.06) 100%);
  box-shadow: 0 0 6rem 1.5rem rgba(221,160,90,0.20);
  animation-delay: -5.5s;
}
@keyframes breathe {
  0%, 100% { transform: scale(1); }
  50%      { transform: scale(1.05); }
}
/* The app honours Reduce Motion, and so does its website. */
@media (prefers-reduced-motion: reduce) {
  .body { animation: none; }
}

/* --- type ---------------------------------------------------------------- */

h1 {
  font-size: clamp(2.6rem, 9vw, 4rem);
  line-height: 1.02;
  letter-spacing: -0.03em;
  font-weight: 300;
  margin: 0 0 0.75rem;
}
.standfirst { font-size: 1.2rem; color: var(--ink-soft); margin: 0 0 2.5rem; text-wrap: pretty; }

h2 {
  font-size: 1.05rem;
  font-weight: 500;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-soft);
  margin: 3rem 0 1rem;
}
h3 { font-size: 1.05rem; font-weight: 600; margin: 2rem 0 0.4rem; }
p { margin: 0 0 1.1rem; }
a { color: var(--left-glow); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: #fff; }

ul.plain { list-style: none; padding: 0; margin: 0 0 1.5rem; }
ul.plain li { position: relative; padding-left: 1.4rem; margin-bottom: 0.6rem; }
ul.plain li::before {
  content: ""; position: absolute; left: 0; top: 0.66em;
  width: 5px; height: 5px; border-radius: 50%; background: var(--right-core);
}

.promises { border-top: 1px solid var(--rule); border-bottom: 1px solid var(--rule); padding: 1.75rem 0; margin: 2.5rem 0; }
.promises ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.7rem; }
.promises li { color: var(--ink); }
.promises li span { color: var(--ink-soft); }

nav.top { display: flex; gap: 1.5rem; padding: 1.75rem 0 0; font-size: 0.95rem; }
nav.top a { color: var(--ink-soft); text-decoration: none; }
nav.top a:hover, nav.top a[aria-current] { color: var(--ink); }

footer {
  margin-top: 4rem; padding-top: 1.75rem;
  border-top: 1px solid var(--rule);
  color: var(--ink-soft); font-size: 0.9rem;
}
footer a { color: var(--ink-soft); }

.updated { color: var(--ink-soft); font-size: 0.9rem; margin-bottom: 2rem; }

code { font: 0.9em ui-monospace, SFMono-Regular, Menlo, monospace; color: var(--right-glow); }

/* Companies Act trading disclosure. A UK limited company must show its
   registered name, number, place of registration and registered office on its
   website — so it is here, quietly, rather than not at all. */
.legal {
  margin-top: 1.25rem;
  font-size: 0.8rem;
  line-height: 1.55;
  color: var(--ink-soft);
  opacity: 0.75;
  max-width: var(--measure);
}