:root {
  color-scheme: light dark;
  --bg: #f5f5f4;
  --card: #ffffff;
  --text: #1c1917;
  --muted: #57534e;
  --accent: #1c1917;
  --on-accent: #ffffff;
  --ok: #15803d;
  --error: #b91c1c;
  --border: #e7e5e4;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0c0a09;
    --card: #1c1917;
    --text: #fafaf9;
    --muted: #a8a29e;
    --accent: #fafaf9;
    --on-accent: #0c0a09;
    --ok: #4ade80;
    --error: #f87171;
    --border: #292524;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 24px 16px;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", "Noto Sans Devanagari", "Noto Sans Telugu", sans-serif;
}

.card {
  width: 100%;
  max-width: 420px;
  padding: 28px 24px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  text-align: center;
}

.merchant { margin: 0; color: var(--muted); font-weight: 600; }
.amount { margin: 8px 0 4px; font-size: 40px; line-height: 1.1; }
.description { margin: 0 0 20px; color: var(--muted); }

.status { margin: 0 0 20px; min-height: 1.5em; }
.status.ok { color: var(--ok); font-weight: 600; }
.status.error { color: var(--error); }

button {
  width: 100%;
  min-height: 48px;
  border-radius: 12px;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}

button[disabled] { opacity: 0.6; cursor: default; }

.pay { border: 0; background: var(--accent); color: var(--on-accent); }
.secondary { margin-top: 12px; border: 1px solid var(--border); background: transparent; color: var(--text); }

.footer { margin-top: 16px; color: var(--muted); font-size: 13px; text-align: center; }