:root {
  color-scheme: dark;
  --bg: #0e1210;
  --card: #171c19;
  --raised: #242b26;
  --text: #f2f6f3;
  --muted: #c5d1c8;
  --green: #8fe3b4;
  --pine: #063322;
  --line: #8a988f;
  --error: #ffb4ab;
  font-family: "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
}
main {
  width: min(640px, 100%);
  margin: 0 auto;
  padding: 18px 20px 40px;
}
h1 { font-size: 28px; line-height: 1.2; margin: 0 0 8px; }
h2 { font-size: 18px; margin: 12px 0 6px; }
.subtitle { color: var(--green); font-size: 18px; font-weight: 600; margin: 0 0 12px; }
.intro, .help, .fine, #grid-status, #status { font-size: 17px; line-height: 1.4; }
.help, .fine, #grid-status { color: var(--muted); }
.tabs { display: flex; gap: 0; margin-top: 16px; }
.tabs button, .grid-tab, .button {
  min-height: 52px;
  font-size: 16px;
  font-weight: 600;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--text);
}
.tabs button { flex: 1; border-radius: 0; }
.tabs button:first-child { border-radius: 999px 0 0 999px; }
.tabs button:last-child { border-radius: 0 999px 999px 0; }
.tabs button[aria-selected="true"], .grid-tab[aria-selected="true"], .button.primary {
  background: #1f7a4d;
  color: white;
  border-color: #1f7a4d;
}
.grid-tab, .button { display: flex; align-items: center; justify-content: center; width: 100%; margin-top: 12px; text-decoration: none; }
.button.disabled { opacity: 0.45; pointer-events: none; }
label { display: block; margin: 14px 0 6px; color: var(--muted); font-size: 15px; }
input {
  width: 100%;
  min-height: 72px;
  padding: 12px 14px;
  font-size: 28px;
  font-weight: 600;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 12px;
}
input:focus { outline: 3px solid var(--green); }
.preview, #readout {
  margin-top: 16px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--card);
}
.role, .label { color: var(--green); font-weight: 600; margin: 8px 0 0; }
.digits, .figure { font-size: 26px; font-weight: 650; margin: 0; overflow-wrap: anywhere; }
.source, .pair { color: var(--muted); }
.pair { font-family: ui-monospace, monospace; font-size: 18px; user-select: text; }
.w3w { margin-top: 16px; padding: 16px; border: 1px solid var(--line); border-radius: 16px; }
@media (max-width: 380px) {
  main { padding-inline: 14px; }
  .tabs button, .grid-tab { font-size: 15px; }
}