/* T-Box visual upgrade: local-only, business-neutral presentation layer. */
:root {
  color-scheme: dark;
  --bg: var(--tbox-background);
  --bg-elev: var(--tbox-surface);
  --surface: rgba(var(--site-white-rgb), 0.055);
  --stroke: rgba(var(--site-white-rgb), 0.1);
  --stroke-hi: rgba(var(--site-white-rgb), 0.2);
  --text: var(--tbox-text-primary);
  --text-dim: var(--tbox-text-secondary);
  --brand: var(--tbox-accent);
  --brand-2: var(--tbox-accent-text);
  --ok: var(--tbox-success);
  --warn: var(--tbox-warning);
  --danger: var(--tbox-danger);
  --action: var(--site-link-hover);
  --panel: var(--tbox-surface);
  --raised: var(--tbox-surface-raised);
  --muted: var(--site-legacy-muted);
  --line: var(--tbox-border);
  --accent: var(--tbox-accent);
  --shadow-sm: 0 8px 24px rgba(var(--site-black-rgb), 0.141176);
  --shadow-lg: 0 24px 64px rgba(var(--site-black-rgb), 0.25098);
  --r8: 8px;
  --r12: 12px;
}

body.design-upgrade {
  background: var(--bg);
  color: var(--text);
  isolation: isolate;
}

@keyframes tbox-aurora {
  from { transform: translate3d(-3%,0,0) rotate(-3deg); }
  to { transform: translate3d(4%,3%,0) rotate(3deg); }
}

body.design-upgrade .nav {
  position: sticky;
  top: 0;
  z-index: 100;
  width: 100%;
  max-width: none;
  padding-inline: max(32px, calc((100vw - 1200px) / 2 + 32px));
  background: rgba(var(--tbox-background-rgb), 0.68);
  border-bottom-color: var(--stroke);
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
}

body.design-upgrade .brand::before {
  border-color: rgba(var(--tbox-accent-rgb), 0.45);
  background: linear-gradient(145deg, rgba(var(--tbox-accent-rgb), 0.34), rgba(var(--tbox-accent-text-rgb), 0.16));
  box-shadow: 0 0 24px rgba(var(--tbox-accent-rgb), 0.28);
}
body.design-upgrade .brand span,
body.design-upgrade .eyebrow,
body.design-upgrade .section-kicker,
body.design-upgrade .card-number {
  color: var(--tbox-accent-text);
}

body.design-upgrade h1,
body.design-upgrade .hero h1 em {
  background: linear-gradient(135deg, var(--tbox-text-primary) 10%, var(--tbox-accent-text) 52%, var(--tbox-accent-text) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: var(--site-clear);
}
body.design-upgrade h1 { font-size: clamp(40px, 6vw, 72px); line-height: 1.05; letter-spacing: -.02em; }
body.design-upgrade h2 { font-size: clamp(28px, 3.4vw, 42px); line-height: 1.2; }
body.design-upgrade .section { border-top-color: rgba(var(--site-white-rgb), 0.08); }
body.design-upgrade .hero { position: relative; isolation: isolate; padding-block: 112px 72px; overflow: clip; }
body.design-upgrade main.wrap .hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background: var(--hero-focus, radial-gradient(ellipse at 18% 18%, rgba(var(--tbox-accent-rgb), 0.35), var(--site-clear) 43%)),
    radial-gradient(ellipse at 80% 22%, rgba(var(--tbox-accent-text-rgb), 0.25), var(--site-clear) 40%);
  filter: blur(80px);
  animation: tbox-aurora 18s ease-in-out infinite alternate;
}
body.design-upgrade .hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: .32;
  background-image: linear-gradient(rgba(var(--site-white-rgb), 0.035) 1px, var(--site-clear) 1px),
    linear-gradient(90deg, rgba(var(--site-white-rgb), 0.035) 1px, var(--site-clear) 1px);
  background-size: 20px 20px;
  mask-image: linear-gradient(to bottom, var(--site-black) 0 45%, var(--site-clear) 90%);
}
body.design-upgrade .hero .lead { color: var(--tbox-text-secondary); }
body.design-upgrade .btn,
body.design-upgrade .hero .actions .btn {
  min-height: 44px;
  height: 44px;
  border-radius: 10px;
  transition: transform .12s ease, filter .12s ease, border-color .12s ease, box-shadow .12s ease;
}
body.design-upgrade .btn.primary,
body.design-upgrade .hero .actions .btn.primary,
body.design-upgrade .pricing .btn.primary,
body.design-upgrade #buy-pending .btn.primary,
body.design-upgrade .tb-download-bar .btn.primary {
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  border-color: var(--site-clear);
  color: var(--site-white);
  min-height: 44px;
  height: 44px;
  box-shadow: 0 8px 24px rgba(var(--tbox-accent-rgb), 0.35);
}
body.design-upgrade .btn.primary:hover,
body.design-upgrade .hero .actions .btn.primary:hover,
body.design-upgrade .pricing .btn.primary:hover,
body.design-upgrade #buy-pending .btn.primary:hover,
body.design-upgrade .tb-download-bar .btn.primary:hover { filter: brightness(1.08); transform: translateY(-2px); box-shadow: 0 12px 30px rgba(var(--tbox-accent-rgb), 0.48); }
body.design-upgrade .hero .actions .btn:not(.primary) {
  background: var(--site-clear);
  border: 1px solid rgba(var(--site-legacy-muted-rgb), 0.3);
}
body.design-upgrade .hero .actions .btn:not(.primary):hover { border-color: var(--site-link-hover); background: var(--site-clear); }
body.design-upgrade .hero-card,
body.design-upgrade .card,
body.design-upgrade .panel,
body.design-upgrade .mock {
  background: var(--surface);
  border: 1px solid var(--stroke);
  border-radius: 16px;
  box-shadow: 0 18px 55px rgba(var(--site-black-rgb), 0.22), inset 0 1px rgba(var(--site-white-rgb), 0.06);
  backdrop-filter: blur(20px) saturate(130%);
  -webkit-backdrop-filter: blur(20px) saturate(130%);
}
body.design-upgrade .hero-card { background: linear-gradient(145deg, rgba(var(--tbox-accent-rgb), 0.18), rgba(var(--tbox-surface-rgb), 0.76)); }
body.design-upgrade .card:hover,
body.design-upgrade .panel:hover,
body.design-upgrade .hero-card:hover { transform: translateY(-4px); border-color: var(--stroke-hi); }
body.design-upgrade .compact-section .cards {
  grid-template-columns: minmax(0,1fr) minmax(0,1.4fr);
  gap: 18px;
}
body.design-upgrade .compact-section .cards > .card:first-child { grid-column: span 2; }
body.design-upgrade .trust-grid { gap: 18px; }
body.design-upgrade .capability-bento { grid-template-columns: repeat(12,minmax(0,1fr)); }
body.design-upgrade .capability-bento > :nth-child(4n+1),
body.design-upgrade .capability-bento > :nth-child(4n+4) { grid-column: span 5; }
body.design-upgrade .capability-bento > :nth-child(4n+2),
body.design-upgrade .capability-bento > :nth-child(4n+3) { grid-column: span 7; }
body.design-upgrade .pricing { gap: 18px; align-items: stretch; }
body.design-upgrade .pricing .price { border-color: var(--stroke); }
body.design-upgrade .pricing .price.recommended {
  z-index: 1;
  transform: scale(1.035);
  border: 1px solid var(--site-clear);
  background: linear-gradient(var(--bg-elev), var(--bg-elev)) padding-box,
    linear-gradient(135deg, var(--brand), var(--brand-2)) border-box;
  box-shadow: 0 0 0 1px rgba(var(--tbox-accent-rgb), 0.16), 0 24px 64px rgba(var(--tbox-accent-rgb), 0.22);
}
body.design-upgrade .pricing .price.recommended:hover { transform: scale(1.055) translateY(-4px); }
body.design-upgrade .price .amount { font-size: 28px; font-weight: 600; }
body.design-upgrade .price .tag {
  padding: 5px 10px;
  border: 1px solid rgba(var(--tbox-accent-text-rgb), 0.35);
  border-radius: 999px;
  background: rgba(var(--tbox-accent-text-rgb), 0.08);
  color: var(--tbox-accent-text);
}
body.design-upgrade .steps { grid-template-columns: repeat(3,minmax(0,1fr)); gap: 18px; }
body.design-upgrade .step { min-height: 132px; padding: 22px; border: 1px solid var(--stroke); border-radius: 16px; background: var(--surface); }
body.design-upgrade .step::before { border-color: rgba(var(--tbox-accent-rgb), 0.5); background: rgba(var(--tbox-accent-rgb), 0.12); }
body.design-upgrade .table-panel,
body.design-upgrade .table { border-color: var(--stroke); }
body.design-upgrade .faq details { background: var(--surface); border-color: var(--stroke); border-radius: 16px; border-left: 2px solid rgba(var(--tbox-accent-rgb), 0.65); }
body.design-upgrade .faq details[open] { border-left-color: var(--brand-2); }
body.design-upgrade .footer { background: rgba(var(--tbox-background-rgb), 0.78); border-top-color: var(--stroke); }

/* Runtime classes used by design.js. */
body.design-upgrade .tb-reveal { opacity: 0; translate: 0 12px; transition: opacity .6s cubic-bezier(.22,.61,.36,1), translate .6s cubic-bezier(.22,.61,.36,1), transform .15s ease, border-color .15s ease; transition-delay: var(--tb-delay,0ms); }
body.design-upgrade .tb-reveal.tb-visible { opacity: 1; translate: 0 0; }
body.design-upgrade .card.tb-visible:hover,
body.design-upgrade .panel.tb-visible:hover { transform: translateY(-4px); border-color: var(--stroke-hi); transition-delay: 0ms; }
body.design-upgrade .tb-download-bar { display: none; position: fixed; left: 50%; bottom: max(16px,env(safe-area-inset-bottom)); transform: translate(-50%,120px); opacity: 0; pointer-events: none; z-index: 9990; width: min(620px,calc(100% - 32px)); align-items: center; justify-content: space-between; gap: 12px; padding: 12px 14px 12px 20px; background: rgba(var(--tbox-surface-rgb), 0.9); border: 1px solid rgba(var(--tbox-accent-text-rgb), 0.3); border-radius: 16px; box-shadow: 0 20px 60px rgba(var(--site-black-rgb), 0.38); backdrop-filter: blur(20px); }
body.design-upgrade .tb-download-bar.tb-visible { display: flex; opacity: 1; transform: translate(-50%,0); pointer-events: auto; transition: opacity .35s, transform .45s cubic-bezier(.22,1,.36,1); }
body.design-upgrade .tb-download-label { font-size: 14px; font-weight: 600; }
body.design-upgrade .tb-download-close { flex: 0 0 auto; min-width: 32px; min-height: 32px; padding: 0; border: 1px solid var(--stroke); border-radius: 8px; color: var(--text-dim); background: var(--site-clear); cursor: pointer; }
body.design-upgrade .tb-download-close:hover { color: var(--text); border-color: var(--stroke-hi); }
body.design-upgrade .tb-download-close:focus-visible,
body.design-upgrade :focus-visible { outline: 2px solid var(--brand-2); outline-offset: 3px; }

/* The visual upgrade owns the keyboard ring globally, including controls
   created later by design.js. */
:focus-visible {
  outline: 2px solid #00D2FF;
  outline-offset: 3px;
}
body.design-upgrade .tb-download-close:focus-visible {
  outline-color: #00D2FF;
}

body.design-upgrade .eyebrow {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border: 1px solid rgba(var(--tbox-accent-text-rgb), 0.28);
  border-radius: 999px;
  background: rgba(var(--tbox-accent-text-rgb), 0.06);
  letter-spacing: .08em;
}
body.design-upgrade .eyebrow::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--brand-2);
  animation: tbox-eyebrow-pulse 1.8s ease-out infinite;
}
@keyframes tbox-eyebrow-pulse {
  0%, 60%, 100% { opacity: .65; transform: scale(1); }
  30% { opacity: 1; transform: scale(1.25); }
}
body.design-upgrade .hero-facts [data-count] { font-variant-numeric: tabular-nums; }
body.design-upgrade .footer-groups { display: grid; grid-template-columns: repeat(4,minmax(0,1fr)); gap: 24px; width: 100%; margin-bottom: 24px; }
body.design-upgrade .footer-group { display: grid; gap: 4px; align-content: start; }
body.design-upgrade .footer-group h3 { font-size: 14px; color: var(--text); }
body.design-upgrade .footer-group a { min-height: 32px; }
body.design-upgrade .footer-copyright { width: 100%; display: flex; justify-content: space-between; gap: 16px; align-items: center; flex-wrap: wrap; }

@media (max-width: 960px) {
  body.design-upgrade .hero { padding-top: 80px; }
  body.design-upgrade .steps { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  body.design-upgrade .nav { padding-inline: 24px; }
  body.design-upgrade .hero { padding-block: 72px 42px; }
  body.design-upgrade .compact-section .cards { grid-template-columns: 1fr; }
  body.design-upgrade .compact-section .cards > .card:first-child { grid-column: auto; }
  body.design-upgrade .capability-bento { grid-template-columns: minmax(0,1fr); }
  body.design-upgrade .capability-bento > .panel { grid-column: auto; }
  body.design-upgrade .pricing .price.recommended { transform: none; }
  body.design-upgrade .pricing .price.recommended:hover { transform: translateY(-4px); }
  body.design-upgrade .tb-download-bar { padding: 10px 12px; grid-template-columns: minmax(0,1fr) auto; }
  body.design-upgrade .tb-download-bar.tb-visible { display: grid; }
  body.design-upgrade .tb-download-label { grid-column: 1; grid-row: 1; }
  body.design-upgrade .tb-download-close { grid-column: 2; grid-row: 1; }
  body.design-upgrade .tb-download-bar .btn { grid-column: 1 / -1; width: 100%; }
  body.design-upgrade .footer-groups { grid-template-columns: repeat(2,minmax(0,1fr)); gap: 16px; }
  body.design-upgrade .footer-copyright { display: block; }
}
@media (prefers-reduced-motion: reduce) {
  body.design-upgrade .hero::before { animation: none !important; }
  body.design-upgrade .eyebrow::before { animation: none !important; }
  body.design-upgrade .tb-reveal,
  body.design-upgrade .tb-download-bar,
  body.design-upgrade .btn,
  body.design-upgrade .card,
  body.design-upgrade .panel { transition: none !important; animation: none !important; }
  body.design-upgrade .tb-reveal { opacity: 1; translate: none; }
  body.design-upgrade .pricing .price.recommended { transform: none; }
}
/* Purchase and setup pages */
.buy-page,.setup-page{padding-block:56px 80px}.buy-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.buy-card{display:flex;flex-direction:column;gap:14px;padding:28px;border:1px solid var(--stroke);border-radius:var(--tbox-radius-3,16px);background:var(--surface);min-width:0}.buy-card.featured{border-color:var(--action);box-shadow:0 0 0 2px rgba(var(--site-link-hover-rgb), 0.2);transform:translateY(-6px)}.buy-card h2{font-size:28px}.buy-price{font-size:42px;font-weight:750;color:var(--text);line-height:1}.buy-price small{font-size:16px;color:var(--muted);font-weight:500}.product-title{color:var(--action);font-size:14px;min-height:48px}.buy-card .btn{margin-top:auto;text-align:center}.trust-line,.cost-note{margin-top:24px;color:var(--muted);text-align:center}.setup-steps{display:grid;gap:20px}.setup-step{display:grid;grid-template-columns:1fr 280px;gap:24px;align-items:center;padding:24px;border:1px solid var(--stroke);border-radius:var(--tbox-radius-3,16px);background:var(--surface)}.setup-step figure{margin:0}.setup-step img{display:block;width:100%;aspect-ratio:16/10;object-fit:cover;border:1px dashed var(--stroke-hi);border-radius:12px;background:var(--panel)}.setup-step figcaption{margin-top:8px;color:var(--muted);font-size:14px;line-height:1.4}.step-no{color:var(--action);font-weight:700;letter-spacing:.08em}.setup-step h2{font-size:24px;margin:8px 0}.setup-step p{color:var(--muted)}
@media (max-width:640px){.buy-page,.setup-page{padding-inline:20px}.buy-grid{grid-template-columns:1fr}.buy-card.featured{transform:none}.setup-step{grid-template-columns:1fr}.setup-step h2{font-size:22px}.product-title{min-height:auto}}

/* 无障碍兜底：程序化 .focus() 不触发 :focus-visible，
   但键盘用户仍需要看到焦点。用同一设计色兜住两种情况。 */
body.design-upgrade .tb-download-close:focus,
body.design-upgrade .tb-download-bar a:focus,
body.design-upgrade iframe:focus {
  outline: 2px solid #00D2FF;
  outline-offset: 3px;
}
/* Product-grade polish: scoped, local-only visual layer. */
body.design-upgrade {
  font-family: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif !important;
  line-height: 1.75;
}
body.design-upgrade h1,
body.design-upgrade h2,
body.design-upgrade h3,
body.design-upgrade h4,
body.design-upgrade h5,
body.design-upgrade h6 {
  line-height: 1.25;
}
body.design-upgrade h1 {
  font-size: clamp(32px, 6vw, 72px);
  letter-spacing: -0.02em;
}
body.design-upgrade p,
body.design-upgrade li {
  max-width: 68ch;
  letter-spacing: 0;
}
body.design-upgrade .nav {
  backdrop-filter: blur(12px) saturate(140%);
  -webkit-backdrop-filter: blur(12px) saturate(140%);
}
body.design-upgrade .hero::before {
  background: var(--hero-focus, radial-gradient(ellipse 72% 90% at 18% 22%, color-mix(in srgb, var(--tbox-accent) 42%, var(--site-clear)), var(--site-clear) 66%)),
    radial-gradient(ellipse 48% 58% at 88% 16%, color-mix(in srgb, var(--tbox-accent-text) 18%, var(--site-clear)), var(--site-clear) 76%);
}
body.design-upgrade .hero::after {
  opacity: .03;
  background-image: linear-gradient(rgba(var(--site-white-rgb), 0.9) 1px, var(--site-clear) 1px),
    linear-gradient(90deg, rgba(var(--site-white-rgb), 0.9) 1px, var(--site-clear) 1px);
}
body.design-upgrade .hero .hero-preview .hero-card {
  transition: transform 200ms ease, box-shadow 200ms ease, border-color 200ms ease;
  box-shadow: 0 34px 78px rgba(var(--site-shadow-ink-rgb), 0.3), 0 14px 30px rgba(var(--site-shadow-ink-rgb), 0.22), 0 3px 8px rgba(var(--site-shadow-ink-rgb), 0.18), inset 0 1px rgba(var(--site-white-rgb), 0.08);
}
body.design-upgrade .hero .hero-preview .hero-card:hover {
  transform: translateY(-2px);
  border-color: var(--stroke-hi);
  box-shadow: 0 42px 92px rgba(var(--site-shadow-ink-rgb), 0.34), 0 18px 36px rgba(var(--site-shadow-ink-rgb), 0.26), 0 5px 12px rgba(var(--site-shadow-ink-rgb), 0.2), inset 0 1px rgba(var(--site-white-rgb), 0.1);
}
body.design-upgrade .visual-options span {
  --answer-alpha: 30%;
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: color-mix(in srgb, var(--tbox-accent-text) 72%, var(--tbox-text-primary));
  border-color: color-mix(in srgb, var(--tbox-accent) 30%, var(--tbox-line));
  background: color-mix(in srgb, var(--tbox-accent) var(--answer-alpha), var(--site-clear));
  transition: background 150ms ease-out, border-color 150ms ease-out, box-shadow 150ms ease-out, transform 150ms ease-out;
}
body.design-upgrade .visual-options span:nth-child(2) { --answer-alpha: 60%; }
body.design-upgrade .visual-options span:nth-child(3) { --answer-alpha: 100%; }
body.design-upgrade .visual-options span::before { content: "⚡"; color: var(--tbox-accent-text); font-family: system-ui, sans-serif; }
body.design-upgrade .visual-options span:nth-child(2)::before { content: "◆"; }
body.design-upgrade .visual-options span:nth-child(3)::before { content: "❖"; }
body.design-upgrade .visual-options span.selected {
  border: 2px solid var(--tbox-accent-text);
  background: color-mix(in srgb, var(--tbox-accent) 34%, var(--tbox-surface));
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--tbox-accent-text) 16%, var(--site-clear)), 0 8px 22px color-mix(in srgb, var(--tbox-accent) 22%, var(--site-clear));
}
body.design-upgrade .pricing .benefits { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; color: var(--tbox-text-secondary); }
body.design-upgrade .pricing .benefits li::before { content: "✓"; display: inline-block; margin-right: 8px; color: var(--tbox-accent-text); font-weight: 700; }
body.design-upgrade .pricing-note,
body.design-upgrade .cost-note {
  color: var(--tbox-accent-text);
  font-weight: 700;
}
body.design-upgrade .price .tag,
body.design-upgrade .plan-card .tag {
  letter-spacing: .02em;
  font-weight: 750;
  box-shadow: 0 0 18px color-mix(in srgb, var(--tbox-accent-text) 18%, var(--site-clear));
}
body.design-upgrade .btn,
body.design-upgrade button {
  transition: transform 150ms ease-out, filter 150ms ease-out, background-color 150ms ease-out, border-color 150ms ease-out, box-shadow 150ms ease-out !important;
}
body.design-upgrade :is(a, button, summary, [role="button"]):active {
  transform: scale(.98) !important;
}
body.design-upgrade .benefits li:empty { display: none; }

@media (prefers-reduced-motion: reduce) {
  body.design-upgrade .btn,
  body.design-upgrade button {
    transition: none !important;
  }
  body.design-upgrade :is(a, button, summary, [role="button"]):active {
    transform: none !important;
  }
}

/* Evolution 1: Geist-inspired grid and consistent control feedback. */
body.design-upgrade .hero::after {
  opacity: .32;
  background-image: linear-gradient(var(--site-grid-line) 1px, var(--site-clear) 1px), linear-gradient(90deg, var(--site-grid-line) 1px, var(--site-clear) 1px);
  background-size: 24px 24px;
}
body.design-upgrade :is(.card, .panel, .buy-card) {
  border-radius: var(--tbox-radius-md);
  box-shadow: var(--tbox-shadow-medium), inset 0 1px 0 var(--site-inset-line);
}
body.design-upgrade :is(a, button, summary) { -webkit-tap-highlight-color: var(--site-clear); }
body.design-upgrade :is(a, summary):hover { text-decoration-thickness: 2px; }
body.design-upgrade summary:hover { color: var(--tbox-accent-text); }
body.design-upgrade :is(button:disabled, .btn[aria-disabled="true"]) {
  opacity: .48;
  cursor: not-allowed;
  filter: none !important;
  transform: none !important;
  box-shadow: none;
}
body.design-upgrade .navlinks a:active,
body.design-upgrade .footer a:active { color: var(--tbox-accent-text); }

/* Evolution 2: Notion-inspired reading rhythm and one clear first-screen focus. */
body.design-upgrade :is(h1, h2, h3) { text-wrap: balance; }
body.design-upgrade .page-header,
body.design-upgrade > main > header.section-head { max-width: 940px; }
body.design-upgrade .page-header .lead,
body.design-upgrade > main > header.section-head > p { max-width: 62ch; line-height: 1.75; }
body.design-upgrade .page-header,
body.design-upgrade > main > header.section-head { margin-inline: auto; }
body.design-upgrade .page-header h1,
body.design-upgrade > main > header.section-head h1 { font-size: clamp(36px, 6vw, 72px); line-height: 1.25; }
body.design-upgrade .buy-price { font-size: clamp(28px, 4vw, 32px); line-height: 1.2; }
body.design-upgrade .price .amount,
body.design-upgrade .plan-card .amount { font-size: clamp(28px, 4vw, 32px); line-height: 1.2; }
body.design-upgrade .error-code { font-size: clamp(18px, 3vw, 24px); line-height: 1; letter-spacing: .02em; margin-bottom: var(--tbox-space-4); }
body.design-upgrade .section-head { gap: var(--tbox-space-6); }
@media (max-width: 640px) {
  body.design-upgrade .section-head { align-items: flex-start; flex-direction: column; gap: var(--tbox-space-3); }
  body.design-upgrade .page-header { padding-block: var(--tbox-space-7) var(--tbox-space-5); }
  body.design-upgrade .page-header h1,
  body.design-upgrade > main > header.section-head h1 { font-size: 36px; }
}

/* Evolution 3: Resend-inspired deep surface hierarchy for evidence blocks. */
body.design-upgrade .setup-proof {
  min-height: 110px;
  padding: var(--tbox-space-4);
  border: var(--tbox-border-thin) solid var(--stroke);
  border-radius: var(--tbox-radius-sm);
  background: linear-gradient(180deg, var(--tbox-surface-raised), var(--tbox-surface));
  color: var(--tbox-text-secondary);
  font-family: ui-monospace, Consolas, monospace;
  font-size: var(--tbox-font-sm);
  line-height: var(--tbox-leading-sm);
  display: grid;
  align-content: center;
}
body.design-upgrade .setup-step { grid-template-columns: minmax(0,1fr) minmax(220px,280px); }
@media (max-width:640px) { body.design-upgrade .setup-step { grid-template-columns: 1fr; } }