:root {
  --ink: #081421;
  --muted: #6a7888;
  --green: #14c98b;
  --dark: #07131f;
  --line: #dce5ec;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  color: var(--ink);
  background: #eef4f6;
}
a { color: inherit; text-decoration: none; }
.checkout-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 28px;
  background:
    linear-gradient(120deg, rgba(7,19,31,.92), rgba(7,19,31,.56)),
    url("https://pay.globaldevsoft.com/assets/hero-usdt-payment-network.png") center / cover;
}
.checkout-card {
  width: min(1080px, 100%);
  border-radius: 8px;
  overflow: hidden;
  background: white;
  box-shadow: 0 34px 120px rgba(0,0,0,.32);
}
header {
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; min-width: 0; }
.brand img { display: block; width: 154px; height: auto; }
header small, .kicker { color: var(--green); font-size: 12px; font-weight: 900; letter-spacing: .16em; }
.checkout-grid { display: grid; grid-template-columns: minmax(0, 1fr) 360px; }
.payment-panel { padding: 52px; }
h1 { margin: 12px 0 18px; font-size: clamp(34px, 5vw, 58px); line-height: 1.08; }
p { color: var(--muted); line-height: 1.8; }
.order-form { display: grid; gap: 14px; margin-top: 32px; }
label { display: grid; gap: 8px; font-size: 13px; font-weight: 800; }
input {
  height: 48px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 14px;
  font: inherit;
  outline: 0;
}
input:focus { border-color: var(--green); box-shadow: 0 0 0 4px rgba(20,201,139,.14); }
button {
  height: 48px;
  border: 0;
  border-radius: 8px;
  background: var(--dark);
  color: white;
  font-weight: 900;
  cursor: pointer;
}
.result {
  margin-top: 24px;
  border: 1px solid #cfece1;
  border-radius: 8px;
  padding: 16px;
  background: #f1fbf7;
  display: grid;
  gap: 6px;
}
.result span { color: var(--muted); font-size: 14px; }
.qr-panel {
  background: #f7fafb;
  border-left: 1px solid var(--line);
  padding: 42px 32px;
  display: grid;
  align-content: start;
  gap: 26px;
}
.qr-box {
  aspect-ratio: 1;
  border-radius: 8px;
  background: white;
  border: 1px solid var(--line);
  display: grid;
  place-items: center;
  position: relative;
  overflow: hidden;
}
.qr-grid {
  position: absolute;
  inset: 34px;
  background:
    linear-gradient(90deg, #122338 16px, transparent 16px) 0 0 / 32px 32px,
    linear-gradient(#122338 16px, transparent 16px) 0 0 / 32px 32px,
    #eef4f6;
  opacity: .38;
}
.qr-box span { position: relative; width: 72px; height: 72px; display: grid; place-items: center; border-radius: 50%; color: white; background: var(--green); font-weight: 900; }
dl { display: grid; gap: 14px; margin: 0; }
dl div { display: flex; justify-content: space-between; gap: 18px; border-bottom: 1px solid var(--line); padding-bottom: 12px; }
dt { color: var(--muted); }
dd { margin: 0; font-weight: 900; }
@media (max-width: 820px) {
  header { gap: 14px; padding: 0 22px; }
  .brand img { width: 140px; }
  .checkout-grid { grid-template-columns: 1fr; }
  .payment-panel { padding: 34px 24px; }
  .qr-panel { border-left: 0; border-top: 1px solid var(--line); }
}