:root {
  --bg: #ffffff;
  --fg: #0a0a0a;
  --muted: #6b7280;
  --line: #e5e7eb;
  --accent: #16a34a;
  --accent-press: #128a3d;
  --radius: 14px;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--fg);
  background: var(--bg);
  font-size: 17px;
  line-height: 1.4;
  -webkit-font-smoothing: antialiased;
}

main {
  max-width: 560px;
  margin: 0 auto;
  padding: 24px 20px 60px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  border-bottom: 1px solid var(--line);
  max-width: 560px;
  margin: 0 auto;
}
.brand { font-weight: 700; font-size: 16px; }
.lang { display: flex; align-items: center; gap: 6px; font-size: 14px; }
.lang-btn {
  background: none; border: none; padding: 4px 6px;
  font: inherit; color: var(--muted); cursor: pointer;
}
.lang-btn.active { color: var(--fg); font-weight: 700; }
.lang-sep { color: var(--muted); }

.hero { padding: 28px 0 20px; text-align: left; }
.hero h1 {
  font-size: 36px;
  line-height: 1.1;
  margin: 0 0 8px;
  letter-spacing: -0.02em;
}
.hero p { margin: 0 0 6px; }
.hero .fee { color: var(--muted); margin: 6px 0 22px; }
.hero .methods { color: var(--muted); font-size: 14px; margin-top: 18px; }

.cta {
  display: block;
  width: 100%;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  padding: 18px 20px;
  font-size: 18px;
  font-weight: 700;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.1s;
}
.cta:hover, .cta:focus-visible { background: var(--accent-press); }
.cta:active { background: var(--accent-press); }

.card {
  margin-top: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
}

form label {
  display: block;
  margin-bottom: 14px;
}
form label > span {
  display: block;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 6px;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}
form input, form select {
  width: 100%;
  padding: 14px 14px;
  font-size: 17px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--fg);
  font-family: inherit;
}
form input:focus, form select:focus {
  outline: none;
  border-color: var(--accent);
}

.receive {
  margin: -8px 0 14px;
  font-size: 14px;
  color: var(--accent);
  font-weight: 600;
}

#instructionsCard h2 {
  font-size: 18px;
  margin: 0 0 10px;
  font-weight: 700;
}
#instructionsCard h2 + h2 { margin-top: 18px; }

.pay-block {
  background: #f9fafb;
  border-radius: 10px;
  padding: 14px;
  margin-bottom: 18px;
  font-size: 15px;
}
.pay-block .row { margin: 4px 0; }
.pay-block .label {
  display: block;
  font-size: 12px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-weight: 600;
  margin-bottom: 2px;
}
.pay-block .value {
  font-weight: 600;
  word-break: break-all;
}
.pay-block a { color: var(--accent); text-decoration: none; }
.pay-block a:hover { text-decoration: underline; }

footer {
  text-align: center;
  font-size: 14px;
  color: var(--muted);
  padding: 30px 20px 40px;
  border-top: 1px solid var(--line);
  margin-top: 30px;
}
footer a { color: var(--accent); text-decoration: none; font-weight: 600; }
footer a:hover { text-decoration: underline; }

@media (max-width: 420px) {
  .hero h1 { font-size: 30px; }
}