/* ===== Theme tokens ===== */

:root[data-theme="light"] {
  --bg: #FFFFFF;
  --fg: #0A0A0F;
  --fg-secondary: #5A5F6E;
  --accent: #A8B3FF;
  --border: #E5E5EA;
  --code-bg: #F5F5F7;
  --header-bg: rgba(255, 255, 255, 0.8);
}

:root[data-theme="dark"] {
  --bg: #100F0D;
  --fg: #F5F5F7;
  --fg-secondary: #A8A8B0;
  --accent: #A8B3FF;
  --border: #2A2A2A;
  --code-bg: #1A1A1A;
  --header-bg: rgba(16, 15, 13, 0.8);
}

/* ===== Reset ===== */

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

html, body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  font-size: 17px;
  line-height: 1.6;
  color: var(--fg);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background 0.2s ease, color 0.2s ease;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1;
}

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

code, pre {
  font-family: 'JetBrains Mono', 'SF Mono', Menlo, Consolas, monospace;
  font-size: 0.9em;
}

a {
  color: inherit;
}

/* ===== Type scale ===== */

h1, h2, h3, h4, h5, h6 {
  line-height: 1.2;
  letter-spacing: -0.01em;
  font-weight: 600;
}

h1 {
  font-size: 2.5rem;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

h2 {
  font-size: 1.75rem;
}

h3 {
  font-size: 1.375rem;
}

h4 {
  font-size: 1rem;
}

@media (min-width: 768px) {
  h1 {
    font-size: 3.5rem;
  }
  h2 {
    font-size: 2.25rem;
  }
  h3 {
    font-size: 1.5rem;
  }
}

p {
  margin-bottom: 1rem;
}

small {
  font-size: 0.875rem;
}

/* ===== Layout ===== */

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  width: 100%;
}

/* ===== Header ===== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: 64px;
  background: var(--header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.site-header > .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  color: var(--fg);
  font-weight: 600;
}

.logo-mark {
  height: 24px;
  width: 24px;
}

.logo-wordmark {
  font-size: 1rem;
  letter-spacing: -0.01em;
}

.site-nav {
  display: flex;
  gap: 28px;
}

.site-nav a {
  color: var(--fg-secondary);
  text-decoration: none;
  font-size: 0.9375rem;
  font-weight: 500;
  transition: color 0.15s ease;
}

.site-nav a:hover {
  color: var(--fg);
}

.header-tools {
  display: flex;
  align-items: center;
  gap: 8px;
}

.theme-toggle {
  background: transparent;
  border: none;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  cursor: pointer;
  color: var(--fg);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s ease;
}

.theme-toggle:hover {
  background: var(--code-bg);
}

[data-theme="light"] .icon-sun {
  display: none;
}

[data-theme="dark"] .icon-moon {
  display: none;
}

.gh-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  color: var(--fg);
  transition: background 0.15s ease;
}

.gh-link:hover {
  background: var(--code-bg);
}

@media (max-width: 768px) {
  .site-nav {
    display: none;
  }
}

/* ===== Mobile nav (hamburger + drawer) ===== */

/* Defensive specificity bump: hardens the .site-nav hide rule above with
   a higher-specificity variant placed later in source order.
   Specificity 0,0,2,0 vs the existing 0,0,1,0 plus later source order
   means this wins the cascade unconditionally; no !important required. */
@media (max-width: 768px) {
  .site-header .site-nav {
    display: none;
  }
}

.hamburger-toggle {
  display: none;
  background: transparent;
  border: none;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  cursor: pointer;
  color: var(--fg);
  align-items: center;
  justify-content: center;
  transition: background 0.15s ease;
  padding: 0;
  font: inherit;
}

.hamburger-toggle:hover {
  background: var(--code-bg);
}

.hamburger-toggle:focus-visible {
  outline: 2px solid var(--fg);
  outline-offset: 2px;
}

@media (max-width: 768px) {
  .hamburger-toggle {
    display: flex;
  }
}

.mobile-nav-drawer {
  display: none;
  position: fixed;
  top: 64px;
  left: 0;
  right: 0;
  background: var(--header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 16px 24px;
  z-index: 99;
}

.mobile-nav-drawer[aria-hidden="false"] {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.mobile-nav-drawer a {
  color: var(--fg);
  text-decoration: none;
  font-size: 1.125rem;
  font-weight: 500;
  padding: 8px 0;
}

.mobile-nav-drawer a:hover {
  color: var(--fg-secondary);
}

/* Categorical hide of the drawer above the mobile breakpoint. The
   !important here is the only one in the file. Justified: defensive
   guarantee that the drawer can never appear on desktop regardless
   of JS state, prior cascade ordering, or class manipulation. This
   is a hard invariant, not a specificity workaround. */
@media (min-width: 769px) {
  .mobile-nav-drawer {
    display: none !important;
  }
}

/* ===== Hero ===== */

.hero {
  padding: 96px 0 64px;
}

.hero-inner {
  text-align: center;
}

.hero-headline {
  max-width: 800px;
  margin: 0 auto;
}

.hero-subhead {
  max-width: 640px;
  margin: 24px auto 32px;
  font-size: 1.25rem;
  color: var(--fg-secondary);
  line-height: 1.5;
}

.hero-subhead code {
  background: var(--code-bg);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.95em;
}

.hero-ctas {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

@media (max-width: 768px) {
  .hero {
    padding: 64px 0 48px;
  }
  .hero-inner {
    text-align: left;
  }
  .hero-headline {
    margin: 0;
  }
  .hero-subhead {
    margin: 24px 0 32px;
    font-size: 1.125rem;
  }
  .hero-ctas {
    justify-content: flex-start;
  }
}

/* ===== Buttons ===== */

.btn {
  padding: 12px 20px;
  border-radius: 8px;
  font-weight: 500;
  font-size: 0.9375rem;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: all 0.15s ease;
  border: 1px solid transparent;
  cursor: pointer;
  font-family: inherit;
}

.btn-primary {
  background: var(--fg);
  color: var(--bg);
}

.btn-primary:hover {
  opacity: 0.85;
  transform: translateY(-1px);
}

.btn-secondary {
  background: transparent;
  color: var(--fg);
  border-color: var(--border);
}

.btn-secondary:hover {
  background: var(--code-bg);
}

/* Specificity bump: .btn.btn-cta (0,0,2,0) vs .btn-primary (0,0,1,0)
   keeps green CTA winning even if a later rule reorders the cascade. */
.btn.btn-cta {
  background: #16a34a;
  color: white;
  border-color: #15803d;
}

.btn.btn-cta:hover {
  background: #15803d;
  transform: translateY(-1px);
}

/* ===== Explainer sections ===== */

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

.explainer-eyebrow {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}

.explainer h2 {
  margin-bottom: 16px;
  max-width: 700px;
}

.explainer p {
  max-width: 700px;
  color: var(--fg-secondary);
  font-size: 1.0625rem;
  margin-bottom: 0;
}

.explainer code {
  background: var(--code-bg);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.9em;
  color: var(--fg);
}

/* ===== CTA strip ===== */

.cta-strip {
  padding: 64px 32px;
  margin-top: 64px;
  background: var(--code-bg);
  border-radius: 16px;
  text-align: center;
}

.cta-strip h2 {
  margin-bottom: 12px;
}

.cta-strip p {
  color: var(--fg-secondary);
  margin-bottom: 24px;
}

.cta-strip-buttons {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.cta-strip .btn-secondary {
  border-color: var(--border);
  background: var(--bg);
}

/* ===== Footer ===== */

.site-footer {
  margin-top: 96px;
  padding: 64px 0 32px;
  border-top: 1px solid var(--border);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 48px;
}

.footer-brand .footer-copy {
  font-size: 0.9375rem;
  color: var(--fg);
  margin-bottom: 8px;
}

.footer-brand .footer-tagline {
  font-size: 0.8125rem;
  color: var(--fg-secondary);
  margin-bottom: 0;
}

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

.footer-link-group h4 {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--fg-secondary);
  margin-bottom: 12px;
  font-weight: 600;
}

.footer-link-group ul {
  list-style: none;
}

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

.footer-link-group a {
  color: var(--fg);
  text-decoration: none;
  font-size: 0.9375rem;
  transition: color 0.15s ease;
}

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

.footer-bottom {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  font-size: 0.8125rem;
  color: var(--fg-secondary);
}

.footer-bottom a {
  color: var(--fg-secondary);
}

.footer-bottom a:hover {
  color: var(--fg);
}

@media (max-width: 768px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .footer-links {
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
  }
}

@media (max-width: 480px) {
  .footer-links {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

/* ===== Article content ===== */

.content {
  max-width: 800px;
  margin: 0 auto;
  padding: 64px 24px;
}

.content-header {
  margin-bottom: 48px;
}

.content-header h1 {
  margin-bottom: 8px;
}

.content-header .lead {
  font-size: 1.25rem;
  color: var(--fg-secondary);
  margin-top: 8px;
  margin-bottom: 8px;
  line-height: 1.5;
}

.content-header time {
  font-size: 0.875rem;
  color: var(--fg-secondary);
}

.content-body h2 {
  margin-top: 48px;
  margin-bottom: 16px;
}

.content-body h3 {
  margin-top: 32px;
  margin-bottom: 12px;
}

.content-body h4 {
  margin-top: 24px;
  margin-bottom: 8px;
}

.content-body p {
  margin-bottom: 16px;
}

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

.content-body li {
  margin-bottom: 8px;
}

.content-body a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 2px;
  text-decoration-thickness: 1px;
}

.content-body a:hover {
  text-decoration-thickness: 2px;
}

.content-body code {
  background: var(--code-bg);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.875em;
}

.content-body pre {
  background: var(--code-bg);
  padding: 16px;
  border-radius: 8px;
  overflow-x: auto;
  margin-bottom: 16px;
  font-size: 0.875rem;
}

.content-body pre code {
  background: transparent;
  padding: 0;
  font-size: inherit;
}

.content-body blockquote {
  border-left: 3px solid var(--border);
  padding: 4px 16px;
  margin: 16px 0;
  color: var(--fg-secondary);
}

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

.content-body th, .content-body td {
  border: 1px solid var(--border);
  padding: 8px 12px;
  text-align: left;
  vertical-align: top;
}

.content-body th {
  background: var(--code-bg);
  font-weight: 600;
}

.content-body hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 32px 0;
}

/* ===== Page list (list.html) ===== */

.page-list {
  list-style: none;
  margin-top: 32px;
  padding-left: 0;
}

.page-list li {
  padding: 16px 0;
  border-top: 1px solid var(--border);
}

.page-list li:last-child {
  border-bottom: 1px solid var(--border);
}

.page-list a {
  color: var(--fg);
  text-decoration: none;
  font-weight: 500;
  font-size: 1.0625rem;
}

.page-list a:hover {
  color: var(--accent);
}

.page-list-desc {
  color: var(--fg-secondary);
  font-weight: 400;
  font-size: 0.9375rem;
}

/* ===== 404 / error page ===== */

.error-page {
  padding: 96px 0 64px;
}

.error-inner {
  text-align: center;
}

.error-eyebrow {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--accent);
  margin-bottom: 12px;
}

.error-headline {
  font-size: 2rem;
  max-width: 720px;
  margin: 0 auto;
}

.error-subhead {
  max-width: 560px;
  margin: 24px auto 32px;
  font-size: 1.125rem;
  color: var(--fg-secondary);
  line-height: 1.5;
}

.error-ctas {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

@media (min-width: 768px) {
  .error-headline {
    font-size: 2.5rem;
  }
}

@media (max-width: 768px) {
  .error-page {
    padding: 64px 0 48px;
  }
  .error-inner {
    text-align: left;
  }
  .error-headline {
    margin: 0;
  }
  .error-subhead {
    margin: 24px 0 32px;
  }
  .error-ctas {
    justify-content: flex-start;
  }
}