:root {
  --bg: oklch(1.000 0.000 0);
  --surface: oklch(0.970 0.006 210);
  --surface-raised: oklch(0.945 0.010 210);
  --ink: oklch(0.220 0.022 210);
  --ink-muted: oklch(0.480 0.018 210);
  --ink-faint: oklch(0.620 0.012 210);
  --primary: oklch(0.420 0.100 210);
  --primary-hover: oklch(0.360 0.105 210);
  --primary-pale: oklch(0.920 0.025 210);
  --accent: oklch(0.620 0.140 55);
  --accent-hover: oklch(0.560 0.150 55);
  --accent-pale: oklch(0.940 0.040 55);
  --rule: oklch(0.880 0.008 210);
  --rule-strong: oklch(0.780 0.020 210);

  --font-sans: "Figtree", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "STSong", serif;
  --font-mono: ui-monospace, "SFMono-Regular", Menlo, monospace;

  --space-xs: 8px;
  --space-sm: 16px;
  --space-md: 24px;
  --space-lg: 40px;
  --space-xl: 64px;
  --space-2xl: 96px;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  --z-sticky: 100;
  --z-dropdown: 150;
  --z-bar: 200;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: var(--primary);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

a:hover {
  color: var(--primary-hover);
}

.container {
  width: min(1120px, calc(100% - 2 * var(--space-md)));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  background: oklch(1 0 0 / 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--rule);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
  min-height: 56px;
}

.wordmark {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--ink);
  text-decoration: none;
  letter-spacing: 0.02em;
}

.wordmark:hover {
  color: var(--primary);
}

.nav-products {
  display: none;
  list-style: none;
  margin: 0;
  padding: 0;
  align-items: center;
  gap: 4px;
}

@media (min-width: 768px) {
  .nav-products {
    display: flex;
  }
}

.nav-item {
  position: relative;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 4px;
  min-height: 44px;
  padding: 0 12px;
  font-size: 0.875rem;
  color: var(--ink-muted);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: color 0.15s, background 0.15s;
}

.nav-link:hover,
.nav-item.is-active > .nav-link {
  color: var(--primary);
}

.nav-item.is-active > .nav-link {
  font-weight: 600;
}

.nav-dropdown {
  position: absolute;
  top: calc(100% - 4px);
  left: 50%;
  transform: translateX(-50%) translateY(6px);
  min-width: 168px;
  margin: 0;
  padding: 6px;
  list-style: none;
  background: var(--bg);
  border: 1px solid var(--rule);
  border-radius: var(--radius-md);
  box-shadow: 0 12px 32px oklch(0.22 0.02 210 / 0.12);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.18s ease-out, transform 0.18s ease-out, visibility 0.18s;
  z-index: var(--z-dropdown);
}

.nav-item.has-dropdown:hover .nav-dropdown,
.nav-item.has-dropdown:focus-within .nav-dropdown {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateX(-50%) translateY(0);
}

.nav-dropdown-link {
  display: block;
  padding: 10px 12px;
  font-size: 0.8125rem;
  color: var(--ink-muted);
  text-decoration: none;
  border-radius: var(--radius-sm);
  white-space: nowrap;
  transition: background 0.12s, color 0.12s;
}

.nav-dropdown-link:hover {
  background: var(--surface);
  color: var(--primary);
}

.sub-product[id],
.category-section[id],
.workflow-section[id],
.contact[id] {
  scroll-margin-top: 72px;
}

.page-hero {
  padding-block: clamp(40px, 6vw, 64px) clamp(24px, 4vw, 40px);
  border-bottom: 1px solid var(--rule);
}

.page-hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 600;
  margin: 0 0 var(--space-sm);
  text-wrap: balance;
}

.page-hero .category-lead {
  margin: 0;
}

.breadcrumb {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--ink-faint);
  margin-bottom: var(--space-sm);
}

.breadcrumb a {
  color: var(--ink-muted);
  text-decoration: none;
}

.breadcrumb a:hover {
  color: var(--primary);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 22px;
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.2s ease-out, color 0.2s ease-out, border-color 0.2s ease-out;
}

.btn-primary {
  background: var(--accent);
  color: oklch(1 0 0);
  border-color: var(--accent);
}

.btn-primary:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
  color: oklch(1 0 0);
}

.btn-secondary {
  background: transparent;
  color: var(--primary);
  border-color: var(--rule-strong);
}

.btn-secondary:hover {
  background: var(--primary-pale);
  color: var(--primary-hover);
}

.btn-sm {
  min-height: 40px;
  padding: 0 16px;
  font-size: 0.875rem;
}

.btn-display {
  cursor: default;
  pointer-events: none;
  user-select: none;
}

.hero {
  padding-block: clamp(48px, 8vw, 80px) clamp(32px, 6vw, 56px);
}

.hero h1 {
  font-family: var(--font-sans);
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.15;
  margin: 0 0 var(--space-sm);
  max-width: none;
}

@media (min-width: 640px) {
  .hero h1 {
    white-space: nowrap;
    font-size: clamp(1.85rem, 3.8vw, 3rem);
  }
}

.hero-lead {
  font-size: clamp(1.05rem, 2vw, 1.2rem);
  color: var(--ink-muted);
  margin: 0 0 var(--space-md);
  max-width: 40em;
  line-height: 1.7;
  text-wrap: pretty;
}

.hero-values {
  list-style: none;
  margin: 0 0 var(--space-md);
  padding: 0;
  display: grid;
  gap: 10px;
  max-width: 36em;
}

@media (min-width: 640px) {
  .hero-values {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-sm);
  }
}

.hero-values li {
  padding: 12px 14px;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  line-height: 1.5;
}

.hero-values strong {
  display: block;
  font-size: 0.9375rem;
  color: var(--ink);
  margin-bottom: 4px;
}

.hero-values span {
  color: var(--ink-muted);
}

.hero-cred {
  font-size: 0.8125rem;
  color: var(--ink-faint);
  margin: 0;
  max-width: 44em;
  line-height: 1.7;
}

.hero-cred strong {
  color: var(--ink-muted);
  font-weight: 600;
}

.hero-note {
  font-size: 0.875rem;
  color: var(--ink-faint);
  margin: 0;
}

.product-gates {
  padding-block: var(--space-lg);
  border-block: 1px solid var(--rule);
  background: var(--surface);
}

.section-intro {
  margin-bottom: var(--space-md);
}

.section-intro h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 600;
  margin: 0 0 var(--space-xs);
  text-wrap: balance;
}

.section-intro p {
  margin: 0;
  color: var(--ink-muted);
  max-width: 50ch;
}

.gate-list {
  list-style: none;
  margin: var(--space-md) 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.gate-link {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: var(--bg);
  border: 1px solid var(--rule);
  border-radius: var(--radius-md);
  text-decoration: none;
  color: inherit;
  transition: background 0.2s ease-out, border-color 0.2s ease-out, box-shadow 0.2s ease-out;
}

.gate-link:hover {
  background: var(--surface);
  border-color: var(--rule-strong);
  box-shadow: 0 2px 12px oklch(0.42 0.1 210 / 0.06);
}

.gate-code {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--primary);
  white-space: nowrap;
}

.gate-body strong {
  display: block;
  font-family: var(--font-serif);
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: 2px;
}

.gate-body span {
  font-size: 0.9rem;
  color: var(--ink-muted);
  line-height: 1.5;
}

.gate-arrow {
  font-size: 1.25rem;
  color: var(--accent);
  transition: transform 0.2s ease-out;
}

.gate-link:hover .gate-arrow {
  transform: translateX(4px);
}

.product-detail {
  padding-block: var(--space-xl);
}

/* ── 方案 A：大类 + 子产品 ── */

.category-section {
  padding-block: var(--space-xl);
  border-top: 1px solid var(--rule);
}

.category-section:first-of-type {
  border-top: none;
}

.category-section--alt {
  background: var(--surface);
}

.category-header {
  margin-bottom: var(--space-lg);
  max-width: 52ch;
}

.category-header h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 600;
  margin: 0 0 var(--space-sm);
  text-wrap: balance;
}

.category-lead {
  margin: 0;
  color: var(--ink-muted);
  font-size: 1.05rem;
  line-height: 1.7;
  text-wrap: pretty;
}

.sub-product {
  margin-top: var(--space-lg);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--rule);
}

.sub-product:first-of-type {
  margin-top: var(--space-md);
}

.sub-product-head {
  margin-bottom: var(--space-md);
}

.sub-product-title {
  font-family: var(--font-serif);
  font-size: clamp(1.15rem, 2vw, 1.4rem);
  font-weight: 600;
  margin: 0 0 6px;
  color: var(--ink);
}

.sub-product-tagline {
  margin: 0 0 var(--space-md);
  font-size: 0.9375rem;
  color: var(--ink-muted);
  max-width: 48ch;
}

.sub-product-body {
  display: grid;
  gap: var(--space-md);
  align-items: start;
}

@media (min-width: 768px) {
  .sub-product-body:not(.sub-product-body--stack) {
    grid-template-columns: 1fr 1.2fr;
    gap: var(--space-lg);
  }
}

.sub-product-body--stack {
  gap: var(--space-md);
}

@media (min-width: 768px) {
  .sub-product-body--split {
    grid-template-columns: minmax(260px, 1fr) minmax(300px, 1.15fr);
    gap: var(--space-xl);
    align-items: stretch;
  }

  .sub-product-body--split .sub-product-text,
  .sub-product-body--split .sub-product-media {
    display: flex;
    flex-direction: column;
  }

  .sub-product-body--split .sub-product-media .shot-grid--compact {
    margin-top: auto;
  }

  .sub-product-body--split .sub-product-media .shot--desktop-compact {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-height: 0;
    margin: 0;
  }

  .sub-product-body--split .sub-product-media .shot--desktop-compact .shot-trigger {
    flex: 1;
    max-height: none;
    height: 100%;
    min-height: 280px;
  }

  .sub-product-body--split .sub-product-media .shot--desktop-compact img {
    height: 100%;
    min-height: 280px;
    max-height: none;
  }

  .sub-product-body--split .sub-product-media .shot--chat {
    flex-shrink: 0;
  }
}

.sub-product-media {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  min-width: 0;
}

.sub-product-text .detail-block h4 {
  font-size: 0.8125rem;
  font-weight: 600;
  margin: 0 0 var(--space-xs);
  color: var(--ink);
}

.sub-product-text .detail-block ul {
  margin: 0;
  padding-left: 1.2em;
  color: var(--ink-muted);
  font-size: 0.9375rem;
}

.sub-product-text .detail-block li {
  margin-bottom: 4px;
}

.sub-product-text .feature-chips {
  margin-top: var(--space-sm);
}

.category-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-top: var(--space-lg);
  padding-top: var(--space-md);
  border-top: 1px solid var(--rule);
}

.product-detail + .product-detail {
  border-top: 1px solid var(--rule);
}

.product-detail-inner {
  display: grid;
  gap: var(--space-lg);
  align-items: start;
}

@media (min-width: 768px) {
  .product-detail-inner {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
  }

  .product-detail--alt .product-detail-inner {
    direction: rtl;
  }

  .product-detail--alt .product-detail-inner > * {
    direction: ltr;
  }
}

.product-meta {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--primary);
  margin-bottom: var(--space-xs);
}

.product-detail h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.35rem, 2.5vw, 1.75rem);
  font-weight: 600;
  line-height: 1.3;
  margin: 0 0 var(--space-sm);
  text-wrap: balance;
}

.product-tagline {
  font-size: 1.05rem;
  color: var(--ink-muted);
  margin: 0 0 var(--space-md);
}

.detail-block {
  margin-bottom: var(--space-md);
}

.detail-block h3 {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--ink);
  margin: 0 0 var(--space-xs);
}

.detail-block ul {
  margin: 0;
  padding-left: 1.2em;
  color: var(--ink-muted);
}

.detail-block li {
  margin-bottom: 6px;
}

.detail-block li strong {
  color: var(--ink);
}

.product-highlights {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
}

.product-showcase {
  margin-top: var(--space-lg);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--rule);
}

.showcase-group + .showcase-group {
  margin-top: var(--space-xl);
}

.showcase-title {
  font-family: var(--font-serif);
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  font-weight: 600;
  margin: 0 0 6px;
  color: var(--ink);
}

.showcase-desc {
  margin: 0 0 var(--space-md);
  font-size: 0.9rem;
  color: var(--ink-muted);
  max-width: 56ch;
}

.shot {
  margin: 0;
}

.shot-trigger {
  display: block;
  width: 100%;
  padding: 0;
  border: none;
  background: none;
  cursor: zoom-in;
  border-radius: var(--radius-md);
  overflow: hidden;
  line-height: 0;
}

.shot-trigger:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 3px;
}

.shot img {
  width: 100%;
  height: auto;
  display: block;
  background: var(--surface-raised);
  border: 1px solid var(--rule);
  border-radius: var(--radius-md);
  transition: box-shadow 0.2s ease-out, transform 0.2s ease-out;
}

.shot-trigger:hover img {
  box-shadow: 0 8px 28px oklch(0.42 0.1 210 / 0.12);
  transform: translateY(-2px);
}

.shot figcaption {
  margin-top: 10px;
  font-size: 0.8125rem;
  color: var(--ink-faint);
  line-height: 1.5;
  text-align: center;
}

.shot--desktop img {
  border-radius: var(--radius-lg);
}

.shot--chat .shot-trigger {
  display: block;
  width: 100%;
  max-width: 100%;
  margin-inline: 0;
  padding: 10px;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius-lg);
}

.shot--chat figcaption {
  margin-top: 8px;
}

.shot--chat img {
  width: 100%;
  height: auto;
  aspect-ratio: unset;
  object-fit: contain;
  object-position: center;
  border: none;
  border-radius: var(--radius-sm);
}

.shot--desktop-compact .shot-trigger {
  display: block;
  width: 100%;
  max-height: 400px;
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: 1px solid var(--rule);
  background: oklch(0.12 0.01 210);
}

.shot--desktop-compact img {
  width: 100%;
  height: 400px;
  object-fit: cover;
  object-position: top center;
  border: none;
  border-radius: 0;
}

.shot--desktop-compact .shot-trigger:hover img {
  transform: none;
}

.shot-grid--compact {
  gap: 8px;
}

.shot-grid--compact .shot--thumb figcaption {
  font-size: 0.7rem;
  margin-top: 6px;
}

.shot--phone .shot-trigger {
  max-width: 280px;
  margin-inline: auto;
  position: relative;
}

.shot--phone .shot-trigger::before {
  content: "";
  position: absolute;
  inset: -8px -6px;
  border: 2px solid var(--rule-strong);
  border-radius: 28px;
  pointer-events: none;
  z-index: 1;
}

.shot--phone img {
  border-radius: 20px;
  aspect-ratio: 9 / 19.5;
  object-fit: cover;
  object-position: top;
}

.shot--lead .shot-trigger {
  max-width: 300px;
}

.shot-layout--split {
  display: grid;
  gap: var(--space-md);
  align-items: start;
}

@media (min-width: 900px) {
  .shot-layout--split {
    grid-template-columns: minmax(240px, 300px) 1fr;
    gap: var(--space-lg);
  }
}

.shot-grid--admin {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-sm);
}

@media (min-width: 600px) {
  .shot-grid--admin {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
  }
}

.shot--thumb .shot-trigger {
  cursor: zoom-in;
}

.shot--thumb img {
  aspect-ratio: 16 / 10;
  object-fit: cover;
  object-position: top left;
}

.shot--thumb figcaption {
  font-size: 0.75rem;
  text-align: left;
}

.shot-row--phones {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-lg);
}

.shot-row--phones .shot {
  flex: 0 1 260px;
}

.shot-row--triple .shot {
  flex: 0 1 220px;
}

@media (min-width: 900px) {
  .shot-row--triple {
    justify-content: flex-start;
  }
}

/* Lightbox */
.lightbox {
  width: min(96vw, 1100px);
  max-height: 92vh;
  padding: 0;
  border: 1px solid var(--rule-strong);
  border-radius: var(--radius-lg);
  background: var(--bg);
  box-shadow: 0 24px 80px oklch(0.22 0.02 210 / 0.25);
}

.lightbox::backdrop {
  background: oklch(0.15 0.02 210 / 0.72);
}

.lightbox-inner {
  padding: var(--space-md);
  max-height: 92vh;
  overflow: auto;
}

.lightbox-close {
  position: sticky;
  top: 0;
  float: right;
  width: 44px;
  height: 44px;
  border: 1px solid var(--rule);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--ink);
  font-size: 1.5rem;
  line-height: 1;
  cursor: pointer;
  z-index: 2;
}

.lightbox-close:hover {
  background: var(--primary-pale);
  color: var(--primary);
}

.lightbox-img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius-md);
  clear: both;
}

.lightbox-caption {
  margin: var(--space-sm) 0 0;
  font-size: 0.875rem;
  color: var(--ink-muted);
  text-align: center;
}

.product-visual {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  min-height: 220px;
}

.visual-label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--ink-faint);
  margin-bottom: var(--space-sm);
}

.feature-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: var(--space-sm);
}

.chip {
  font-size: 0.8125rem;
  padding: 6px 12px;
  background: var(--accent-pale);
  color: oklch(0.35 0.08 55);
  border-radius: var(--radius-sm);
}

.product-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-top: var(--space-md);
}

.workflow-section {
  padding-block: var(--space-xl);
  background: var(--surface);
  border-block: 1px solid var(--rule);
}

.workflow-section h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin: 0 0 var(--space-xs);
  text-wrap: balance;
}

.workflow-section > .container > p {
  color: var(--ink-muted);
  margin: 0 0 var(--space-lg);
  max-width: 52ch;
}

.workflow {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  padding: var(--space-md);
  background: var(--bg);
  border: 1px solid var(--rule);
  border-radius: var(--radius-lg);
}

@media (min-width: 768px) {
  .workflow {
    flex-direction: row;
    align-items: stretch;
    gap: 0;
    padding: var(--space-lg);
  }
}

.flow-node {
  flex: 1;
  padding: var(--space-sm);
  text-align: center;
  opacity: 0;
  transform: translateY(12px);
}

.flow-node.is-visible {
  animation: node-in 0.5s ease-out forwards;
}

@keyframes node-in {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.flow-node-inner {
  padding: var(--space-sm) var(--space-md);
  border: 2px solid var(--accent);
  border-radius: var(--radius-md);
  background: var(--bg);
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
}

.flow-node strong {
  font-size: 0.9375rem;
  color: var(--ink);
}

.flow-node span {
  font-size: 0.8125rem;
  color: var(--ink-muted);
}

.flow-connector {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  font-size: 1.25rem;
  padding: 4px 0;
}

@media (min-width: 768px) {
  .flow-connector {
    padding: 0 4px;
    flex: 0 0 28px;
  }
}

.scenarios {
  padding-block: var(--space-xl);
}

.scenario-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: var(--space-md);
}

.tab-btn {
  min-height: 44px;
  padding: 0 16px;
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--ink-muted);
  background: var(--bg);
  border: 1px solid var(--rule);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.tab-btn:hover {
  border-color: var(--rule-strong);
  color: var(--ink);
}

.tab-btn[aria-selected="true"] {
  background: var(--primary);
  color: oklch(1 0 0);
  border-color: var(--primary);
}

.scenario-panel {
  display: none;
  padding: var(--space-lg);
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius-lg);
}

.scenario-panel.is-active {
  display: block;
  animation: fade-in 0.2s ease-out;
}

@keyframes fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

.scenario-panel h3 {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  margin: 0 0 var(--space-sm);
}

.scenario-grid {
  display: grid;
  gap: var(--space-md);
}

@media (min-width: 600px) {
  .scenario-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.scenario-card h4 {
  font-size: 0.875rem;
  font-weight: 600;
  margin: 0 0 6px;
  color: var(--ink);
}

.scenario-card p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--ink-muted);
}

.scenario-product {
  margin-top: var(--space-md);
  padding-top: var(--space-md);
  border-top: 1px dashed var(--rule-strong);
  font-size: 0.9rem;
  color: var(--ink-muted);
}

.scenario-product strong {
  color: var(--primary);
}

.about {
  padding-block: var(--space-xl);
  border-top: 1px solid var(--rule);
  background: var(--surface);
}

.about-inner {
  display: grid;
  gap: var(--space-lg);
}

@media (min-width: 768px) {
  .about-inner {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
    align-items: start;
  }
}

.about h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 600;
  margin: 0 0 var(--space-sm);
  text-wrap: balance;
}

.about-lead {
  font-size: 1.05rem;
  color: var(--ink);
  margin: 0 0 var(--space-sm);
  line-height: 1.7;
  max-width: 40em;
}

.about-lead strong {
  font-weight: 600;
}

.about-desc {
  font-size: 0.9375rem;
  color: var(--ink-muted);
  margin: 0;
  line-height: 1.75;
  max-width: 40em;
}

.about-points {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.about-points li {
  padding: var(--space-sm) var(--space-md);
  background: var(--bg);
  border: 1px solid var(--rule);
  border-radius: var(--radius-md);
}

.about-points strong {
  display: block;
  font-size: 0.9375rem;
  color: var(--ink);
  margin-bottom: 4px;
}

.about-points span {
  font-size: 0.875rem;
  color: var(--ink-muted);
  line-height: 1.5;
}

.contact {
  padding-block: var(--space-xl);
  border-top: 1px solid var(--rule);
}

.contact-grid {
  display: grid;
  gap: var(--space-lg);
  align-items: center;
}

@media (min-width: 768px) {
  .contact-grid {
    grid-template-columns: minmax(max-content, 1fr) auto;
  }

  .contact-lead {
    white-space: nowrap;
  }
}

.contact h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin: 0 0 var(--space-sm);
  text-wrap: balance;
}

.contact-lead,
.contact-grid > div > p {
  color: var(--ink-muted);
  margin: 0 0 var(--space-md);
  max-width: none;
  line-height: 1.7;
}

.nowrap {
  white-space: nowrap;
}

.qr-box {
  width: 160px;
  height: 160px;
  background: var(--surface);
  border: 1px solid var(--rule-strong);
  border-radius: var(--radius-md);
  overflow: hidden;
  flex-shrink: 0;
}

.qr-box img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.site-footer {
  padding-block: var(--space-lg) calc(var(--space-lg) + 60px);
  background: var(--surface);
  border-top: 1px solid var(--rule);
}

@media (min-width: 769px) {
  .site-footer {
    padding-bottom: var(--space-lg);
  }
}

.footer-shadow {
  font-size: 0.8125rem;
  color: var(--ink-faint);
  margin: 0;
  text-align: center;
}

.mobile-bar {
  display: flex;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: var(--z-bar);
  padding: 10px var(--space-md);
  gap: var(--space-sm);
  background: oklch(1 0 0 / 0.95);
  backdrop-filter: blur(8px);
  border-top: 1px solid var(--rule);
}

.mobile-bar .btn {
  flex: 1;
}

@media (min-width: 769px) {
  .mobile-bar {
    display: none;
  }
}