:root {
  --bg: #f6f7fb; --card: #fff; --ink: #1a1f36; --muted: #697386;
  --accent: #635bff; --accent-ink: #fff; --line: #e3e8ee; --danger: #c0123c;
}
* { box-sizing: border-box; }
body { margin: 0; font: 16px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif; background: var(--bg); color: var(--ink); }
.wrap { max-width: 920px; margin: 0 auto; padding: 40px 20px 60px; }
.narrow { max-width: 560px; text-align: center; padding-top: 80px; }
h1 { margin: 0 0 6px; } h2 { margin-top: 0; font-size: 1.1rem; }
.muted { color: var(--muted); } .small { font-size: .875rem; }
.hidden { display: none !important; }
.banner { text-align: center; padding: 8px; font-weight: 600; font-size: .9rem; letter-spacing: .02em; }
.banner.sandbox { background: #fff4d6; color: #7a4d00; }
.banner.live { background: #ffe1e6; color: var(--danger); }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 16px; margin: 28px 0; }
.product, .cards { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 20px; }
.product h3 { margin: 0; }
.price { font-size: 1.5rem; font-weight: 700; margin: 8px 0 14px; }
label { display: block; margin-bottom: 14px; color: var(--muted); }
input[type=number] { width: 64px; margin-left: 6px; padding: 6px; border: 1px solid var(--line); border-radius: 6px; font: inherit; }
button, .btn { display: inline-block; width: 100%; padding: 11px 16px; border: 0; border-radius: 8px; background: var(--accent);
  color: var(--accent-ink); font: inherit; font-weight: 600; cursor: pointer; text-decoration: none; text-align: center; }
.btn { width: auto; margin-top: 20px; }
button:disabled { opacity: .6; cursor: wait; }
button:focus-visible, .btn:focus-visible { outline: 3px solid #a5a1ff; outline-offset: 2px; }
.error { color: var(--danger); }
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 8px 4px; border-top: 1px solid var(--line); }
code { font-family: ui-monospace, Menlo, monospace; font-size: .92em; }