html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  background: #f6f6f6;
  color: #111;
  font-family: Inter, "Noto Sans JP", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.checkout {
  box-sizing: border-box;
  display: grid;
  gap: 48px;
  margin: 0 auto;
  max-width: 920px;
  min-height: 100vh;
  padding: 32px 24px 56px;
}

.brand {
  align-items: center;
  color: #111;
  display: inline-flex;
  font-size: 14px;
  font-weight: 800;
  gap: 10px;
  justify-self: start;
  text-decoration: none;
}

.brand span {
  font-weight: 700;
}

.panel {
  align-self: center;
  background: #fff;
  border: 1px solid rgba(17, 17, 17, .08);
  border-radius: 24px;
  box-shadow: 0 24px 80px rgba(17, 17, 17, .08);
  box-sizing: border-box;
  display: grid;
  gap: 24px;
  padding: clamp(28px, 6vw, 56px);
}

.eyebrow {
  color: #666;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .12em;
  margin: 0;
  text-transform: uppercase;
}

h1 {
  font-size: clamp(34px, 7vw, 72px);
  letter-spacing: 0;
  line-height: 1.02;
  margin: 0;
}

.lead {
  color: #4f4f4f;
  font-size: clamp(15px, 2.2vw, 18px);
  font-weight: 600;
  line-height: 1.8;
  margin: 0;
  max-width: 680px;
}

.summary {
  align-items: center;
  background: #f7f7f7;
  border: 1px solid rgba(17, 17, 17, .07);
  border-radius: 16px;
  display: flex;
  justify-content: space-between;
  padding: 18px 20px;
}

.summary span {
  color: #666;
  font-size: 14px;
  font-weight: 700;
}

.summary strong {
  font-size: 22px;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.checkout-form {
  display: contents;
}

.primary,
.secondary {
  align-items: center;
  border-radius: 999px;
  border: 0;
  cursor: pointer;
  display: inline-flex;
  font-size: 15px;
  font-weight: 800;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  text-decoration: none;
}

.primary {
  background: #111;
  color: #fff;
}

.secondary {
  background: #eee;
  color: #111;
}

@media (max-width: 520px) {
  .checkout {
    gap: 36px;
    padding: 22px 16px 40px;
  }

  .panel {
    border-radius: 20px;
  }

  .summary {
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
  }

  .actions {
    flex-direction: column;
  }
}