/* ========================================
   Tools for Divers Marketing Site
   Clean, professional, utility-focused
   ======================================== */

/* --- Reset & Base --- */

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  /* Surface */
  --color-bg: #FAFAFA;
  --color-bg-secondary: #FFFFFF;
  --color-bg-tertiary: #F2F2F2;

  /* Content */
  --color-text: #1A1A1A;
  --color-text-secondary: #666666;
  --color-text-tertiary: #999999;

  /* Interactive */
  --color-accent: #5A7A99;
  --color-accent-hover: #4A6A89;

  /* Border */
  --color-border: #E6E6E6;

  /* Status */
  --color-danger: #FF3B30;
  --color-success: #34C759;
  --color-warning: #FF9500;
  --color-info: #5A7A99;

  /* Layout */
  --max-width: 1080px;
  --max-width-text: 720px;

  /* Radius (brand spec) */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  /* Legacy aliases (migrating) */
  --radius: var(--radius-sm);

  /* Spacing (4pt grid) */
  --space-xxxs: 2px;
  --space-xxs: 4px;
  --space-xs: 8px;
  --space-sm: 12px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-xxl: 48px;
  --space-xxxl: 64px;

  /* Animation */
  --anim-quick: 0.2s ease-in-out;
  --anim-standard: 0.3s ease-in-out;
  --anim-slow: 0.5s ease-in-out;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0D0D0D;
    --color-bg-secondary: #1A1A1A;
    --color-bg-tertiary: #262626;
    --color-text: #F2F2F2;
    --color-text-secondary: #B3B3B3;
    --color-text-tertiary: #808080;
    --color-accent: #7A9AB8;
    --color-accent-hover: #8AAAC8;
    --color-border: #333333;
    --color-danger: #FF453A;
    --color-success: #30D158;
    --color-warning: #FF9F0A;
    --color-info: #7A9AB8;
  }
}

/* --- Accessibility --- */

.skip-to-content {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  padding: var(--space-xs) var(--space-md);
  background: var(--color-accent);
  color: #FFFFFF;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  text-decoration: none;
  z-index: 1000;
  transition: top var(--anim-quick);
}

.skip-to-content:focus {
  top: var(--space-xs);
}

:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* Remove focus outline for mouse users */
:focus:not(:focus-visible) {
  outline: none;
}

/* --- Base --- */

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Helvetica, Arial, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* --- Utilities --- */

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* --- Header --- */

.site-header {
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg-secondary);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.site-logo {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.02em;
  white-space: nowrap;
  flex-shrink: 0;
}

.site-logo-mark img {
  display: block;
  width: 24px;
  height: 24px;
}

.nav-toggle-input {
  display: none;
}

.nav-toggle {
  display: none;
  cursor: pointer;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 1px;
  transition: transform var(--anim-quick), opacity var(--anim-quick);
}

.site-nav {
  display: flex;
  gap: 24px;
}

.site-nav a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color var(--anim-quick);
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--color-accent);
}

/* --- Buttons --- */

.btn {
  display: inline-block;
  padding: var(--space-sm) 28px;
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  text-align: center;
  transition: background var(--anim-quick), color var(--anim-quick);
  cursor: pointer;
  border: none;
  min-height: 44px;
}

.btn-primary {
  background: var(--color-accent);
  color: #FFFFFF;
}

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

.btn-secondary {
  background: var(--color-bg-tertiary);
  color: var(--color-text-secondary);
}

.btn-outline {
  background: transparent;
  color: var(--color-accent);
  border: 1px solid var(--color-accent);
}

.btn-outline:hover {
  background: var(--color-accent);
  color: #FFFFFF;
}

/* --- Hero (Home) --- */

.hero {
  padding: 80px 0;
  text-align: center;
}

.hero h1 {
  font-size: 2.75rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 24px;
}

.hero .subtitle {
  font-size: 1.25rem;
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto 40px;
}

/* --- App Cards (Home) --- */

.app-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  padding: 0 0 80px;
}

.app-cards--centered {
  grid-template-columns: 1fr;
  max-width: 420px;
  margin: 0 auto;
}

.app-cards--two {
  grid-template-columns: repeat(2, 1fr);
  max-width: 840px;
  margin: 0 auto;
}

.app-card {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl) var(--space-lg);
  text-align: center;
  text-decoration: none;
  color: inherit;
  transition: border-color var(--anim-quick), box-shadow var(--anim-quick);
}

.app-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

.app-card-icon {
  width: 64px;
  height: 64px;
  border-radius: 14px;
  background: var(--color-bg-tertiary);
  margin: 0 auto 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-accent);
  object-fit: cover;
}

.app-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.app-card p {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

/* --- Per-App Card Accents --- */

.app-card[data-app="dalton"] .app-card-icon {
  color: #00E68D;
  background: transparent;
}

.app-card[data-app="dalton"]:hover {
  border-color: #00E68D;
}

.app-card[data-app="slate"] .app-card-icon {
  color: #D4A84B;
  background: transparent;
}

.app-card[data-app="slate"]:hover {
  border-color: #D4A84B;
}

.app-card[data-app="prism"] .app-card-icon {
  color: #E85D4A;
  background: transparent;
}

.app-card[data-app="prism"]:hover {
  border-color: #E85D4A;
}

.app-card[data-app="slatelink"] .app-card-icon {
  color: #D4A84B;
  background: transparent;
}

.app-card[data-app="slatelink"]:hover {
  border-color: #D4A84B;
}

.app-card[data-app="diveshopos"] .app-card-icon {
  color: #0E9AA7;
  background: transparent;
}

.app-card[data-app="diveshopos"]:hover {
  border-color: #0E9AA7;
}

.app-cards--three {
  grid-template-columns: repeat(3, 1fr);
}

/* --- App Hero (App pages) --- */

.app-hero {
  padding: 64px 0;
  text-align: center;
  background: var(--color-bg-tertiary);
  border-bottom: 1px solid var(--color-border);
}

.app-hero-content {
  max-width: 600px;
  margin: 0 auto;
}

.app-icon {
  width: 96px;
  height: 96px;
  border-radius: 22px;
  margin-bottom: 20px;
}

.app-icon-placeholder {
  width: 96px;
  height: 96px;
  border-radius: 22px;
  background: var(--color-accent);
  color: #FFFFFF;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  font-weight: 800;
  margin: 0 auto 20px;
}

.app-hero h1 {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

.app-tagline {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  margin-bottom: 28px;
}

/* --- Page Content --- */

.page-content {
  padding: 48px 0 80px;
}

.page-content .container {
  max-width: var(--max-width-text);
}

.app-page .container {
  max-width: var(--max-width);
}

.page-content h1 {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 24px;
}

.page-content h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-top: 48px;
  margin-bottom: 16px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
}

.page-content h2:first-of-type {
  border-top: none;
  padding-top: 0;
}

.page-content h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-top: 32px;
  margin-bottom: 12px;
}

.page-content p {
  margin-bottom: 16px;
  color: var(--color-text);
}

.page-content ul,
.page-content ol {
  margin-bottom: 16px;
  padding-left: 24px;
}

.page-content li {
  margin-bottom: 6px;
}

.page-content a {
  color: var(--color-accent);
  text-decoration: none;
}

.page-content a:hover {
  text-decoration: underline;
}

.page-content strong {
  font-weight: 600;
}

.page-content hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: 48px 0;
}

.page-content blockquote {
  border-left: 3px solid var(--color-accent);
  padding: 12px 20px;
  margin: 24px 0;
  background: var(--color-bg-tertiary);
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--color-text-secondary);
}

/* --- Features Grid (App pages) --- */

.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin: 32px 0;
}

.feature {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.feature h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  margin: 0 0 8px;
}

.feature p {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  margin: 0;
  line-height: 1.5;
}

/* --- Hero Screenshots --- */

.hero-screenshots {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: flex-end;
  gap: 0;
  margin-top: 48px;
}

.hero-screenshot {
  width: auto;
  max-height: 480px;
  border-radius: 12px;
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.3);
  object-fit: contain;
}

.hero-screenshot--back {
  position: relative;
  z-index: 1;
  transform: translateX(40px) rotate(-2deg);
  opacity: 0.85;
}

.hero-screenshot--front {
  position: relative;
  z-index: 2;
  transform: translateX(-40px) rotate(1deg);
}

/* --- Product Showcase (Home) --- */

.product-showcase {
  padding: 80px 0;
  border-top: 1px solid var(--color-border);
}

.product-card {
  display: flex;
  align-items: center;
  gap: 48px;
  margin-bottom: 80px;
}

.product-card:last-child {
  margin-bottom: 0;
}

.product-card--reversed {
  flex-direction: row-reverse;
}

.product-card-text {
  flex: 1;
  min-width: 0;
}

.product-card-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
}

.product-card-icon {
  width: 56px;
  height: 56px;
  border-radius: 13px;
}

.product-card-header h2 {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0;
  padding: 0;
  border: none;
}

.product-card-description {
  font-size: 1.0625rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
  margin-bottom: 24px;
}

.product-card-badges {
  display: flex;
  gap: 12px;
  align-items: center;
}

.product-card-learn-more {
  display: inline-block;
  margin-top: 16px;
  font-size: 0.95rem;
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--anim-quick);
}

.product-card-learn-more:hover {
  color: var(--color-accent-hover);
}

.store-badge img {
  height: 40px;
  width: auto;
}

.product-card-screenshots {
  flex: 1;
  display: flex;
  gap: 12px;
  align-items: flex-start;
  min-width: 0;
  max-width: 480px;
}

.product-screenshot {
  width: calc(50% - 6px);
  max-height: 420px;
  object-fit: contain;
  border-radius: 10px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
}

/* --- Credibility Section (Home) --- */

.credibility-section {
  padding: 64px 0;
  border-top: 1px solid var(--color-border);
}

.credibility-section h2 {
  text-align: center;
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 48px;
  border: none;
  padding: 0;
}

.credibility-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.credibility-item {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px;
}

.credibility-item h3 {
  font-family: "SF Mono", SFMono-Regular, ui-monospace, Menlo, Monaco, monospace;
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 10px;
  color: var(--color-text);
}

.credibility-item p {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin: 0;
}

/* --- Error Page --- */

.error-page {
  text-align: center;
  padding: 120px 24px;
}

.error-page h1 {
  font-size: 6rem;
  font-weight: 800;
  color: var(--color-text-tertiary);
  margin-bottom: 16px;
}

.error-page p {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  margin-bottom: 32px;
}

/* --- Footer --- */

.site-footer {
  border-top: 1px solid var(--color-border);
  background: var(--color-bg-secondary);
  padding: 48px 0 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-bottom: 40px;
}

.footer-col h4 {
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-tertiary);
  margin-bottom: 12px;
}

.footer-col ul {
  list-style: none;
  padding: 0;
}

.footer-col li {
  margin-bottom: 8px;
}

.footer-col a {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  text-decoration: none;
}

.footer-col a:hover {
  color: var(--color-accent);
}

.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding-top: 24px;
  text-align: center;
}

.footer-bottom p {
  font-size: 0.8125rem;
  color: var(--color-text-tertiary);
  margin-bottom: 4px;
}

/* --- Responsive --- */

@media (max-width: 768px) {
  .hero {
    padding: 48px 0;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero .subtitle {
    font-size: 1.0625rem;
  }

  .app-cards {
    grid-template-columns: 1fr;
    gap: 16px;
    padding-bottom: 48px;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .hero-screenshots {
    margin-top: 32px;
  }

  .hero-screenshot {
    max-height: 360px;
    border-radius: 12px;
  }

  .hero-screenshot--back {
    transform: translateX(24px) rotate(-2deg);
  }

  .hero-screenshot--front {
    transform: translateX(-24px) rotate(1deg);
  }

  .product-showcase {
    padding: 48px 0;
  }

  .product-card,
  .product-card--reversed {
    flex-direction: column;
    gap: 32px;
    margin-bottom: 56px;
  }

  .product-card-header h2 {
    font-size: 1.5rem;
  }

  .product-card-screenshots {
    width: 100%;
  }

  .credibility-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .credibility-section {
    padding: 40px 0;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-xs) 0;
  }

  .site-nav a {
    display: block;
    padding: var(--space-sm) var(--space-lg);
    font-size: 0.9375rem;
  }

  .site-nav a:hover {
    background: var(--color-bg-tertiary);
  }

  .nav-toggle-input:checked ~ .site-nav {
    display: flex;
  }

  .nav-toggle-input:checked ~ .nav-toggle span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .nav-toggle-input:checked ~ .nav-toggle span:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle-input:checked ~ .nav-toggle span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  .header-inner {
    position: relative;
  }

  .app-hero {
    padding: 40px 0;
  }

  .app-hero h1 {
    font-size: 1.75rem;
  }

  .page-content {
    padding: 32px 0 48px;
  }

  .page-content h1 {
    font-size: 1.5rem;
  }

  .page-content h2 {
    font-size: 1.25rem;
    margin-top: 32px;
  }

  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }
}

/* --- Blog --- */

.blog-page .container {
  max-width: var(--max-width-text);
}

.blog-header {
  margin-bottom: 32px;
}

.blog-header h1 {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

.blog-subtitle {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
}

.blog-categories {
  display: flex;
  gap: 8px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

.category-filter {
  font-size: 0.8125rem;
  font-weight: 500;
  padding: 6px 14px;
  border-radius: 100px;
  background: var(--color-bg-tertiary);
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: background var(--anim-quick), color var(--anim-quick);
}

.category-filter:hover,
.category-filter.active {
  background: var(--color-accent);
  color: #FFFFFF;
}

.blog-footer {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
}

.blog-footer a {
  color: var(--color-accent);
  text-decoration: none;
}

.blog-footer a:hover {
  text-decoration: underline;
}

/* --- Post Card --- */

.post-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.post-card {
  padding: 24px 0;
  border-bottom: 1px solid var(--color-border);
}

.post-card:first-child {
  padding-top: 0;
}

.post-card-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 8px;
}

.post-card-meta time {
  font-size: 0.8125rem;
  color: var(--color-text-tertiary);
}

.post-card-title,
.page-content .post-card-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 0 0 6px 0;
  padding: 0;
  border: none;
}

.post-card-title a {
  color: var(--color-text);
  text-decoration: none;
}

.post-card-title a:hover {
  color: var(--color-accent);
}

.post-card-excerpt,
.page-content .post-card-excerpt {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
  margin: 0;
}

/* --- Category Tag --- */

.category-tag {
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 3px 10px;
  border-radius: 100px;
  background: var(--color-bg-tertiary);
  color: var(--color-text-secondary);
}

.category-education {
  background: rgba(90, 122, 153, 0.1);
  color: var(--color-accent);
}

.category-updates {
  background: rgba(52, 199, 89, 0.1);
  color: var(--color-success);
}

@media (prefers-color-scheme: dark) {
  .category-education {
    background: rgba(122, 154, 184, 0.15);
    color: var(--color-accent);
  }

  .category-updates {
    background: rgba(48, 209, 88, 0.15);
    color: var(--color-success);
  }
}

/* --- Post Page --- */

.post-header {
  margin-bottom: 40px;
}

.post-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.post-meta time {
  font-size: 0.875rem;
  color: var(--color-text-tertiary);
}

.post-header h1 {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 12px;
}

.post-description {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.post-body h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-top: 48px;
  margin-bottom: 16px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
}

.post-body h2:first-of-type {
  border-top: none;
  padding-top: 0;
}

.post-body h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-top: 32px;
  margin-bottom: 12px;
}

.post-body p {
  margin-bottom: 16px;
  line-height: 1.7;
}

.post-body ul,
.post-body ol {
  margin-bottom: 16px;
  padding-left: 24px;
}

.post-body li {
  margin-bottom: 6px;
  line-height: 1.6;
}

.post-body a {
  color: var(--color-accent);
  text-decoration: none;
}

.post-body a:hover {
  text-decoration: underline;
}

.post-body img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  margin: 24px 0;
}

.post-phone-showcase {
  display: flex;
  align-items: flex-start;
  gap: 32px;
  margin: 32px 0;
}

.post-phone-showcase img {
  width: 240px;
  max-height: 400px;
  object-fit: cover;
  object-position: top;
  flex-shrink: 0;
  margin: 0;
}

.post-phone-showcase .post-phone-text {
  flex: 1;
  min-width: 0;
}

.post-phone-showcase .post-phone-text p:first-child {
  margin-top: 0;
}

.post-phone-pair {
  display: flex;
  gap: 24px;
  margin: 32px 0;
  justify-content: center;
}

.post-phone-pair img {
  width: calc(50% - 12px);
  max-width: 280px;
  margin: 0;
}

@media (max-width: 768px) {
  .post-phone-showcase {
    flex-direction: column;
    align-items: center;
  }

  .post-phone-showcase img {
    width: 200px;
  }

  .post-phone-pair {
    flex-direction: column;
    align-items: center;
  }

  .post-phone-pair img {
    width: 200px;
  }
}

.post-body strong {
  font-weight: 600;
}

.post-body blockquote {
  border-left: 3px solid var(--color-accent);
  padding: 12px 20px;
  margin: 24px 0;
  background: var(--color-bg-tertiary);
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--color-text-secondary);
}

/* --- Formula Display --- */

.formula-block {
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin: 24px 0;
  text-align: center;
  font-family: "SF Mono", SFMono-Regular, ui-monospace, Menlo, Monaco, monospace;
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: 0.01em;
  overflow-x: auto;
}

.formula-block .formula-name {
  color: var(--color-accent);
}

/* --- Variable Table --- */

.variable-table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0 24px;
  font-size: 0.9375rem;
}

.variable-table th {
  text-align: left;
  font-weight: 600;
  padding: 10px 16px;
  border-bottom: 2px solid var(--color-border);
  color: var(--color-text-secondary);
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.variable-table td {
  padding: 10px 16px;
  border-bottom: 1px solid var(--color-border);
}

.variable-table code {
  font-family: "SF Mono", SFMono-Regular, ui-monospace, Menlo, Monaco, monospace;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-accent);
}

/* --- Worked Example --- */

.worked-example {
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin: 24px 0;
}

.worked-example h4 {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-tertiary);
  margin-bottom: 12px;
}

.worked-example .step {
  font-family: "SF Mono", SFMono-Regular, ui-monospace, Menlo, Monaco, monospace;
  font-size: 0.9375rem;
  margin-bottom: 8px;
  color: var(--color-text);
}

.worked-example .step:last-child {
  font-weight: 600;
  color: var(--color-accent);
}

/* --- Dalton Promo Banner --- */

.dalton-promo {
  margin: 48px 0 0;
  padding-top: 32px;
  border-top: 1px solid var(--color-border);
}

.dalton-promo-inner {
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  text-align: center;
}

.dalton-promo-icon {
  width: 48px;
  height: 48px;
  border-radius: 11px;
  margin-bottom: 12px;
}

.dalton-promo strong {
  display: block;
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.dalton-promo p {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  margin-bottom: 20px;
  line-height: 1.5;
}

/* --- Slate Promo Banner --- */

.slate-promo {
  margin: 48px 0 0;
  padding-top: 32px;
  border-top: 1px solid var(--color-border);
}

.slate-promo-inner {
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  text-align: center;
}

.slate-promo-icon {
  width: 48px;
  height: 48px;
  border-radius: 11px;
  margin-bottom: 12px;
}

.slate-promo strong {
  display: block;
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.slate-promo p {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  margin-bottom: 20px;
  line-height: 1.5;
}

.slate-promo .btn-primary,
.dalton-promo .btn-primary {
  color: #FFFFFF;
}

/* --- Post Footer --- */

.post-footer {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
}

.back-to-blog {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-accent);
  text-decoration: none;
}

.back-to-blog:hover {
  text-decoration: underline;
}

/* --- Footer 4-column --- */

.footer-grid {
  grid-template-columns: repeat(4, 1fr);
}

/* --- Blog Responsive --- */

@media (max-width: 768px) {
  .blog-header h1 {
    font-size: 1.5rem;
  }

  .post-header h1 {
    font-size: 1.5rem;
  }

  .formula-block {
    font-size: 1rem;
    padding: 16px;
  }

  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* --- Language Banner --- */

.lang-banner {
  display: none;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 10px 24px;
  background: var(--color-bg-tertiary);
  border-bottom: 1px solid var(--color-border);
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.lang-banner.visible {
  display: flex;
}

.lang-banner-text {
  display: none;
}

.lang-banner-cta {
  display: none;
  font-weight: 600;
  color: var(--color-accent);
  text-decoration: none;
}

.lang-banner-cta:hover {
  text-decoration: underline;
}

.lang-banner-dismiss {
  background: none;
  border: none;
  font-size: 1.25rem;
  line-height: 1;
  color: var(--color-text-tertiary);
  cursor: pointer;
  padding: 4px 8px;
  margin-left: 4px;
}

.lang-banner-dismiss:hover {
  color: var(--color-text);
}

/* --- Store Banner --- */

.store-banner {
  display: none;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 10px 24px;
  background: var(--color-accent-bg, rgba(0, 122, 255, 0.08));
  border-bottom: 1px solid var(--color-border);
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.store-banner.visible {
  display: flex;
}

.store-banner-icon {
  font-size: 1.125rem;
}

.store-banner-text {
  flex: 0 1 auto;
}

.store-banner-cta {
  font-weight: 600;
  color: var(--color-accent);
  text-decoration: none;
  white-space: nowrap;
}

.store-banner-cta:hover {
  text-decoration: underline;
}

.store-banner-dismiss {
  background: none;
  border: none;
  font-size: 1.25rem;
  line-height: 1;
  color: var(--color-text-tertiary);
  cursor: pointer;
  padding: 4px 8px;
  margin-left: 4px;
}

.store-banner-dismiss:hover {
  color: var(--color-text);
}

/* --- Language Switcher (Footer) --- */

.language-switcher {
  margin-top: 12px;
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
}

.language-switcher a {
  color: var(--color-text-secondary);
  text-decoration: none;
}

.language-switcher a:hover {
  color: var(--color-accent);
}

.language-switcher strong {
  color: var(--color-text);
}

.lang-sep {
  margin: 0 6px;
  color: var(--color-text-tertiary);
}