:root {
  color-scheme: light;
  --ink: #1c2430;
  --muted: #647084;
  --line: #d9e0e8;
  --panel: #ffffff;
  --page: #f4f7f5;
  --accent: #087f5b;
  --accent-dark: #056348;
  --warn: #a45c00;
  --good: #087f5b;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--page);
  color: var(--ink);
  font-family: Arial, "Microsoft YaHei", sans-serif;
}

.topbar {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 24px;
  padding: 32px clamp(18px, 4vw, 56px) 20px;
  border-bottom: 1px solid var(--line);
  background: #fbfcfb;
}

h1,
h2,
h3,
p {
  margin: 0;
}

h1 {
  font-size: clamp(28px, 5vw, 48px);
  line-height: 1.05;
}

.eyebrow {
  margin-bottom: 8px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
}

.lookup {
  display: flex;
  gap: 8px;
  min-width: min(100%, 420px);
}

input,
button {
  min-height: 44px;
  border-radius: 6px;
  border: 1px solid var(--line);
  font: inherit;
}

input {
  width: 100%;
  padding: 0 12px;
  background: #fff;
  color: var(--ink);
}

button {
  padding: 0 16px;
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
  cursor: pointer;
  white-space: nowrap;
}

button:hover {
  background: var(--accent-dark);
}

button.secondary,
button.ghost {
  background: #fff;
  color: var(--accent);
}

main {
  padding: 28px clamp(18px, 4vw, 56px) 56px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.product {
  display: grid;
  gap: 14px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.product h3 {
  font-size: 20px;
}

.price {
  font-size: 28px;
  font-weight: 700;
}

.muted {
  color: var(--muted);
  line-height: 1.5;
}

.checkout {
  margin-top: 24px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.hidden {
  display: none;
}

.checkout-header,
.actions,
.copy-row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.checkout-header {
  justify-content: space-between;
  margin-bottom: 20px;
}

.payment-layout {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 20px;
}

.qr-wrap {
  display: grid;
  place-items: center;
  min-height: 220px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f8faf8;
}

.payment-fields {
  display: grid;
  gap: 14px;
}

label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 13px;
}

label input {
  color: var(--ink);
  font-size: 15px;
}

.result {
  margin-top: 18px;
  padding: 12px;
  border-radius: 6px;
  background: #f8faf8;
  color: var(--muted);
  white-space: pre-wrap;
}

.result.good {
  color: var(--good);
}

.result.warn {
  color: var(--warn);
}

@media (max-width: 760px) {
  .topbar,
  .lookup,
  .payment-layout,
  .checkout-header,
  .actions,
  .copy-row {
    align-items: stretch;
    flex-direction: column;
  }

  .payment-layout {
    grid-template-columns: 1fr;
  }
}