:root {
  --apple-blue: #0071e3;
  --apple-blue-dark: #2997ff;
  --apple-blue-hover: #0077ed;
  --bg-hero: #000000;
  --bg-neutral-dark: #111111;
  --bg-card-dark: #1d1d1f;
  --bg-neutral: #f5f5f7;
  --bg-card: #ffffff;
  --text-primary: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.72);
  --text-tertiary: rgba(255, 255, 255, 0.48);
  --border-dark: rgba(255, 255, 255, 0.1);
  --border-light: rgba(0, 0, 0, 0.08);
  --shadow-card: rgba(0, 0, 0, 0.22) 3px 5px 30px 0px;
  --nav-bg: rgba(0, 0, 0, 0.72);
  --radius-sm: 5px;
  --radius-md: 8px;
  --radius-lg: 14px;
  --radius-pill: 999px;
  --font-serif: "Crimson Pro", Georgia, "Times New Roman", serif;
  --font-sans: system-ui, -apple-system, "Helvetica Neue", Arial, sans-serif;
  --maxw: 1100px;
  --ease-standard: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-out-quint: cubic-bezier(0.16, 1, 0.3, 1);
  --surface-page: #000000;
  --surface-section: #111111;
  --surface-card: #1d1d1f;
  --text-body: #ffffff;
  --text-muted: rgba(255, 255, 255, 0.72);
  --text-soft: rgba(255, 255, 255, 0.48);
  --border-color: rgba(255, 255, 255, 0.1);
}

[data-theme="light"] {
  --surface-page: #ffffff;
  --surface-section: #f5f5f7;
  --surface-card: #ffffff;
  --text-body: #1d1d1f;
  --text-muted: rgba(0, 0, 0, 0.68);
  --text-soft: rgba(0, 0, 0, 0.5);
  --border-color: rgba(0, 0, 0, 0.08);
  --nav-bg: rgba(255, 255, 255, 0.82);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--text-body);
  background:
    radial-gradient(circle at 50% 0%, rgba(0, 113, 227, 0.16), transparent 34%),
    var(--surface-page);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: inherit;
  text-decoration: none;
}

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

button {
  border: 0;
  background: transparent;
  color: inherit;
  font: inherit;
  cursor: pointer;
}

.skip-link {
  position: absolute;
  left: 16px;
  top: -64px;
  z-index: 1400;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  background: #ffffff;
  color: #000000;
  font-size: 13px;
  font-weight: 600;
  transition: top 180ms ease;
}

.skip-link:focus {
  top: 10px;
}

.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1200;
  height: 48px;
  display: flex;
  align-items: center;
  padding: 0 22px;
  background: var(--nav-bg);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border-color);
}

.site-nav-inner {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.site-logo {
  font-family: var(--font-serif);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.site-links {
  display: flex;
  align-items: center;
  gap: 22px;
  list-style: none;
  padding: 0;
  margin: 0;
}

.site-links a {
  font-size: 12px;
  color: var(--text-muted);
  position: relative;
  padding-bottom: 2px;
}

.site-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 0;
  height: 1px;
  background: currentColor;
  transition: width 260ms var(--ease-standard);
}

.site-links a:hover,
.site-links a:focus-visible,
.site-links a[aria-current="page"] {
  color: var(--text-body);
}

.site-links a:hover::after,
.site-links a:focus-visible::after,
.site-links a[aria-current="page"]::after {
  width: 100%;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.icon-btn {
  min-width: 44px;
  min-height: 44px;
  height: 28px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  border: 0;
  color: rgba(255, 255, 255, 0.8);
  transition: color 200ms ease, background 200ms ease, transform 150ms ease;
}

.icon-btn:hover,
.icon-btn:focus-visible {
  color: #ffffff;
  background: rgba(255, 255, 255, 0.08);
}

.icon-btn:active {
  transform: scale(0.98);
}

.page-shell {
  padding-top: 48px;
  flex: 1 0 auto;
  width: 100%;
}

.container {
  width: min(var(--maxw), calc(100% - 44px));
  margin: 0 auto;
}

.hero {
  padding: 84px 0 56px;
}

.hero-eyebrow,
.section-label {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--text-soft);
  margin: 0 0 18px;
}

.hero-title {
  margin: 0;
  max-width: 980px;
  font-family: var(--font-serif);
  font-size: clamp(40px, 7vw, 78px);
  font-weight: 600;
  line-height: 0.98;
  letter-spacing: -0.05em;
}

.hero-subtitle {
  max-width: 760px;
  margin: 24px 0 0;
  font-size: clamp(18px, 2.2vw, 24px);
  line-height: 1.5;
  color: var(--text-muted);
}

.hero-actions,
.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.btn-primary,
.btn-outline {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 10px 18px;
  border-radius: var(--radius-pill);
  font-size: 14px;
  font-weight: 500;
  transition: transform 150ms ease, border-color 180ms ease, background 180ms ease;
}

.btn-primary {
  background: var(--apple-blue);
  color: #ffffff;
}

.btn-primary:hover,
.btn-primary:focus-visible {
  background: var(--apple-blue-hover);
}

.btn-outline {
  border: 1px solid var(--border-color);
  color: var(--text-body);
}

.btn-outline:hover,
.btn-outline:focus-visible {
  border-color: rgba(0, 113, 227, 0.55);
}

.section {
  padding: 0 0 72px;
}

.section-header {
  max-width: 760px;
  margin-bottom: 26px;
}

.section-heading {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(30px, 4.4vw, 48px);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.05;
}

.section-sub {
  margin: 16px 0 0;
  font-size: 17px;
  line-height: 1.6;
  color: var(--text-muted);
}

.card-grid,
.post-grid,
.post-list,
.info-grid {
  display: grid;
  gap: 18px;
}

.post-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.info-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.post-card,
.info-card,
.cta-card,
.toc-card,
.author-card,
.meta-card {
  background: var(--surface-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}

.post-card {
  overflow: hidden;
}

.post-card-link {
  display: block;
  padding: 22px;
}

.post-card-link:hover .post-card-title,
.post-card-link:focus-visible .post-card-title {
  color: var(--apple-blue-dark);
}

.post-card--text-only .post-card-title {
  margin-top: 0;
  margin-bottom: 0;
  font-size: clamp(30px, 3vw, 44px);
  max-width: 18ch;
}

.post-card--text-only .post-card-excerpt {
  margin-top: 0;
  max-width: 62ch;
  font-size: 17px;
}

.post-card--text-only .post-card-link {
  display: grid;
  gap: 18px;
  align-content: start;
  min-height: 196px;
  padding: 34px 36px;
}

.post-list {
  max-width: 980px;
}

.post-card-cover {
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background: var(--surface-section);
}

.post-card-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.post-card-body,
.info-card,
.cta-card,
.toc-card,
.author-card,
.meta-card {
  padding: 22px;
}

.post-meta-row,
.pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.pill,
.post-date,
.post-category {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0 10px;
  border-radius: 999px;
  font-size: 12px;
  color: var(--text-muted);
  background: color-mix(in srgb, var(--surface-section) 86%, transparent);
  border: 1px solid var(--border-color);
}

.post-card-title,
.card-title {
  margin: 16px 0 12px;
  font-family: var(--font-serif);
  font-size: 28px;
  font-weight: 600;
  line-height: 1.08;
  letter-spacing: -0.03em;
}

.post-card-excerpt,
.card-copy,
.info-copy,
.cta-copy {
  margin: 0;
  font-size: 16px;
  line-height: 1.65;
  color: var(--text-muted);
}

.text-link {
  margin-top: 16px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  color: var(--apple-blue-dark);
}

.text-link:hover,
.text-link:focus-visible {
  text-decoration: underline;
}

.page-heading {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(34px, 5vw, 60px);
  font-weight: 600;
  line-height: 1.02;
  letter-spacing: -0.04em;
}

.page-intro {
  max-width: 720px;
  margin: 20px 0 0;
  font-size: 18px;
  line-height: 1.65;
  color: var(--text-muted);
}

.info-card h2,
.info-card h3,
.cta-card h2,
.toc-card h2,
.author-card h2,
.meta-card h2 {
  margin: 0 0 12px;
  font-size: 15px;
  letter-spacing: -0.01em;
}

.info-list,
.toc-list,
.meta-list,
.footer-links {
  list-style: none;
  padding: 0;
  margin: 0;
}

.info-list li,
.meta-list li {
  padding: 10px 0;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  line-height: 1.6;
}

.info-list li:first-child,
.meta-list li:first-child {
  padding-top: 0;
  border-top: 0;
}

.article-shell {
  display: grid;
  grid-template-columns: minmax(240px, 0.72fr) minmax(0, 1.65fr);
  gap: 28px;
  align-items: start;
}

.article-main {
  min-width: 0;
}

.article-side {
  position: sticky;
  top: 88px;
  align-self: start;
  width: 100%;
}

.toc-card {
  text-align: left;
}

.article-header {
  padding: 84px 0 30px;
}

.article-kicker {
  margin: 0 0 16px;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--text-soft);
}

.article-title {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(38px, 5.2vw, 62px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.05em;
}

.article-subtitle {
  margin: 20px 0 0;
  max-width: 780px;
  font-size: 19px;
  line-height: 1.6;
  color: var(--text-muted);
}

.article-meta {
  margin-top: 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.figure {
  margin: 0 0 26px;
  overflow: hidden;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  background: var(--surface-card);
}

.figure img {
  width: 100%;
}

.figure figcaption {
  padding: 14px 18px 18px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--text-soft);
}

.rich-text {
  display: grid;
  gap: 22px;
}

.rich-text p,
.rich-text li {
  margin: 0;
  font-size: 17px;
  line-height: 1.8;
  color: var(--text-body);
}

.rich-text h2 {
  margin: 18px 0 0;
  font-family: var(--font-serif);
  font-size: 30px;
  font-weight: 600;
  line-height: 1.08;
  letter-spacing: -0.03em;
}

.rich-text ul,
.rich-text ol {
  margin: 0;
  padding-left: 20px;
  display: grid;
  gap: 10px;
}

.references-list {
  margin: 0;
  padding-left: 20px;
  display: grid;
  gap: 12px;
}

.references-list li {
  color: var(--text-muted);
  line-height: 1.75;
}

.quote {
  padding: 20px 22px;
  border-left: 3px solid var(--apple-blue);
  background: color-mix(in srgb, var(--surface-card) 78%, transparent);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  color: var(--text-muted);
}

.stats-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.stat-card {
  padding: 18px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: color-mix(in srgb, var(--surface-card) 78%, transparent);
}

.stat-value {
  font-family: var(--font-serif);
  font-size: 34px;
  line-height: 1;
  letter-spacing: -0.04em;
}

.stat-label {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-muted);
}

.author-card {
  display: grid;
  gap: 14px;
}

.author-head {
  display: flex;
  align-items: center;
  gap: 14px;
}

.author-head img {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  object-fit: cover;
}

.author-name {
  margin: 0;
  font-size: 18px;
}

.author-role {
  margin: 4px 0 0;
  font-size: 13px;
  color: var(--text-muted);
}

.toc-list {
  display: grid;
  gap: 10px;
}

.toc-list a {
  display: block;
  color: var(--text-muted);
  line-height: 1.5;
}

.toc-list a:hover,
.toc-list a:focus-visible {
  color: var(--text-body);
}

.footer {
  padding: 30px 0 44px;
  border-top: 1px solid var(--border-color);
  margin-top: auto;
  width: 100%;
}

.footer-inner {
  display: grid;
  gap: 16px;
  align-items: center;
}

.footer-inner.is-centered {
  justify-items: center;
  text-align: center;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  color: var(--text-muted);
}

.footer-links a:hover,
.footer-links a:focus-visible {
  color: var(--text-body);
}

.footer-copy {
  margin: 0;
  font-size: 12px;
  line-height: 1.7;
  color: var(--text-soft);
  text-align: center;
}

[data-theme="light"] .icon-btn {
  color: rgba(29, 29, 31, 0.82);
}

[data-theme="light"] .icon-btn:hover,
[data-theme="light"] .icon-btn:focus-visible {
  color: #1d1d1f;
  background: rgba(0, 0, 0, 0.06);
}

.page-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1300;
  height: 2px;
}

.page-progress-bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--apple-blue), var(--apple-blue-dark));
  box-shadow: 0 0 16px rgba(0, 113, 227, 0.45);
}

@media (max-width: 900px) {
  .post-grid,
  .info-grid,
  .stats-row,
  .article-shell {
    grid-template-columns: 1fr;
  }

  .post-list {
    max-width: none;
  }

  .post-card--text-only .post-card-link {
    min-height: auto;
  }

  .article-side {
    position: static;
  }
}

@media (max-width: 720px) {
  .site-nav {
    height: auto;
    padding: 10px 22px;
  }

  .site-nav-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-links {
    flex-wrap: wrap;
    gap: 12px 18px;
  }

  .page-shell {
    padding-top: 92px;
  }

  .hero,
  .article-header {
    padding-top: 56px;
  }

  .hero-actions,
  .cta-row {
    flex-direction: column;
  }

  .btn-primary,
  .btn-outline {
    width: 100%;
  }
}