/* Book's green, as the app grows its colours from it, light and dark. Nothing from other origins. */
:root {
  color-scheme: light dark;
  --bg: #f6f8f5;
  --card: #ffffff;
  --text: #1a1c19;
  --muted: #5a6157;
  --line: #d9ded5;
  --accent: #1b5e20;
  --accent-text: #ffffff;
  --code-bg: #eef2ec;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111410;
    --card: #1a1e19;
    --text: #e2e4de;
    --muted: #a0a89c;
    --line: #2d332b;
    --accent: #8fd18f;
    --accent-text: #0b1f0c;
    --code-bg: #232922;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, Ubuntu, Cantarell, sans-serif;
}
a { color: var(--accent); }
header, main, footer { max-width: 720px; margin: 0 auto; padding: 0 16px; }
header { padding-top: 20px; }
.brand { display: inline-flex; align-items: center; gap: 12px; color: var(--text); text-decoration: none; font-weight: 600; font-size: 22px; }
h1 { font-size: 30px; line-height: 1.2; margin: 28px 0 12px; }
h2 { font-size: 22px; margin: 0 0 12px; }
section { margin: 0 0 24px; }
#get-book, #about, #pair, #group, #report, #bad {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 4px 24px 20px;
}
#get-book { padding-top: 20px; }
.lead { font-size: 19px; }
.points { padding-left: 20px; }
.points li { margin: 6px 0; }
.muted { color: var(--muted); font-size: 15px; }
.hidden { display: none !important; }

.button, button {
  font: inherit;
  font-size: 16px;
  border-radius: 999px;
  padding: 10px 20px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--text);
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
}
.button { background: var(--accent); color: var(--accent-text); border-color: var(--accent); font-weight: 600; }
.actions { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }
button:focus-visible, .button:focus-visible, a:focus-visible, pre:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }

.qr { width: 220px; max-width: 100%; aspect-ratio: 1; border-radius: 8px; overflow: hidden; }
.qr svg { display: block; width: 100%; height: 100%; }

.tabs { display: flex; gap: 8px; margin-bottom: 12px; }
.platform[aria-selected="true"] { background: var(--accent); color: var(--accent-text); border-color: var(--accent); }
.command { display: flex; gap: 8px; align-items: flex-start; margin: 8px 0; }
pre, code { background: var(--code-bg); border-radius: 8px; font-family: ui-monospace, "DejaVu Sans Mono", monospace; font-size: 14px; }
code { padding: 1px 5px; }
pre { margin: 0; padding: 10px 12px; overflow-x: auto; flex: 1; min-width: 0; white-space: pre; }
footer { padding-bottom: 32px; }
footer p { color: var(--muted); font-size: 14px; }