:root {
  --b4e-header-height: 82px;
}

.checkout-header {
  grid-template-columns: minmax(220px, 340px) minmax(420px, 1fr);
  gap: clamp(22px, 4vw, 56px);
  min-height: var(--b4e-header-height);
  padding: 12px clamp(18px, 3vw, 44px);
}

.brand-lockup {
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 12px;
}

.brand-mark {
  width: 46px;
  height: 46px;
  border-radius: 9px;
}

.brand-title {
  font-size: 15px;
  line-height: 1.2;
}

.brand-subtitle {
  display: -webkit-box;
  overflow: hidden;
  font-size: 12px;
  line-height: 1.25;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.progress {
  gap: 14px;
}

.progress:before,
.progress:after {
  top: 14px;
  height: 5px;
}

.step {
  grid-template-columns: 30px minmax(0, 1fr);
  gap: 9px;
  align-items: center;
  font-size: 13px;
}

.step-number {
  width: 30px;
  height: 30px;
  font-size: 13px;
}

.step span:last-child {
  margin-top: 2px;
  font-size: 11px;
}

.page-shell {
  width: min(1120px, calc(100% - 40px));
  padding: 32px 0 48px;
}

.journey-grid {
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 28px;
}

.guide-card {
  top: calc(var(--b4e-header-height) + 18px);
  padding: 20px;
  box-shadow: 0 14px 38px rgba(15, 23, 42, 0.08);
}

.guide-card h2 {
  margin: 10px 0 6px;
  font-size: 21px;
}

.guide-card p {
  margin-bottom: 12px;
  font-size: 14px;
}

.guide-list {
  padding-top: 10px;
}

.guide-list li {
  padding: 7px 0 7px 25px;
  font-size: 14px;
}

.section-title {
  margin-bottom: 18px;
  font-size: clamp(32px, 4vw, 48px);
}

.notice-card {
  padding: 14px 18px;
  margin-bottom: 16px;
}

.billing-row {
  margin-bottom: 16px;
}

@media (max-width: 860px) {
  :root {
    --b4e-header-height: auto;
  }

  .checkout-header {
    position: relative;
    grid-template-columns: 1fr;
    gap: 13px;
    min-height: 0;
    padding: 12px 16px 14px;
  }

  .brand-lockup {
    grid-template-columns: 42px minmax(0, 1fr);
    gap: 10px;
  }

  .brand-mark {
    width: 42px;
    height: 42px;
  }

  .brand-title {
    font-size: 14px;
  }

  .brand-subtitle {
    font-size: 11px;
    -webkit-line-clamp: 1;
  }

  .progress {
    gap: 6px;
  }

  .progress:before,
  .progress:after {
    top: 13px;
  }

  .step {
    grid-template-columns: 28px minmax(0, 1fr);
    gap: 6px;
    font-size: 12px;
  }

  .step-number {
    width: 28px;
    height: 28px;
    font-size: 12px;
  }

  .step span:last-child {
    display: none;
  }

  .page-shell {
    width: min(100% - 24px, 720px);
    padding: 18px 0 34px;
  }

  .journey-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .main-panel {
    order: 2;
  }

  .guide-card {
    position: static;
    order: 1;
    padding: 16px 18px;
    border-radius: 12px;
    box-shadow: 0 10px 28px rgba(15, 23, 42, 0.07);
  }

  .guide-badge,
  .guide-list {
    display: none;
  }

  .guide-card h2 {
    margin: 0 0 4px;
    font-size: 21px;
  }

  .guide-card p {
    margin: 0;
    font-size: 13px;
    line-height: 1.4;
  }

  .section-title {
    margin-bottom: 12px;
    font-size: 31px;
  }

  .notice-card {
    display: none;
  }

  .billing-row {
    padding: 12px;
    margin-bottom: 14px;
  }
}

@media (max-width: 520px) {
  .checkout-header {
    padding-inline: 12px;
  }

  .brand-lockup {
    grid-template-columns: 38px minmax(0, 1fr);
  }

  .brand-mark {
    width: 38px;
    height: 38px;
  }

  .progress {
    overflow: hidden;
  }

  .step {
    grid-template-columns: 26px minmax(0, 1fr);
    min-width: 0;
    font-size: 11px;
  }

  .step-number {
    width: 26px;
    height: 26px;
    font-size: 11px;
  }

  .page-shell {
    width: calc(100% - 20px);
    padding-top: 12px;
  }

  .guide-card {
    padding: 14px 15px;
  }

  .guide-card h2 {
    font-size: 19px;
  }

  .section-title {
    font-size: 28px;
  }

  .billing-row {
    display: grid;
    gap: 8px;
  }

  .billing-row select {
    max-width: none;
  }
}