:root {
  --teal: #0d9488;
  --teal-dark: #0f766e;
  --ink: #134e4a;
  --bg: #f0fdfa;
  --card: #fff;
  --muted: #5f6b6a;
  --radius: 12px;
  --shadow: 0 8px 24px rgba(13, 148, 136, 0.12);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  line-height: 1.55;
  color: var(--ink);
  background: linear-gradient(180deg, var(--bg) 0%, #fff 40%);
  min-height: 100vh;
}

a {
  color: var(--teal-dark);
}

header {
  padding: 2rem 1.25rem 1rem;
  max-width: 720px;
  margin: 0 auto;
}

.brand {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 0;
}

.tagline {
  margin: 0.25rem 0 0;
  color: var(--muted);
  font-size: 1.05rem;
}

.badge {
  display: inline-block;
  margin-top: 1rem;
  background: var(--teal);
  color: #fff;
  padding: 0.25rem 0.65rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 600;
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 1.25rem 3rem;
}

.card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.25rem 1.5rem;
  margin-bottom: 1.25rem;
  border: 1px solid rgba(13, 148, 136, 0.15);
}

.card h2 {
  margin: 0 0 0.75rem;
  font-size: 1.15rem;
}

.grid {
  display: grid;
  gap: 0.75rem;
}

label {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  font-size: 0.9rem;
  font-weight: 500;
}

select,
input[type="number"] {
  padding: 0.5rem 0.65rem;
  border: 1px solid #cbd5e1;
  border-radius: 8px;
  font-size: 1rem;
}

.checkbox {
  flex-direction: row;
  align-items: center;
  font-weight: 400;
}

.price {
  font-size: 2rem;
  font-weight: 700;
  color: var(--teal-dark);
  margin: 0.5rem 0 0;
}

.price small {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--muted);
}

.err {
  color: #b91c1c;
  font-size: 0.9rem;
}

.success {
  color: var(--teal-dark);
  font-size: 0.95rem;
  font-weight: 500;
}

.muted {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0 0 0.75rem;
}

.btn {
  align-self: start;
  background: var(--teal);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 0.6rem 1.1rem;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
}

.btn:hover {
  background: var(--teal-dark);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

footer {
  max-width: 720px;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 2rem;
  border-top: 1px solid #e2e8f0;
  font-size: 0.85rem;
  color: var(--muted);
}

footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 0.75rem;
}