/* ============================================
   BASE RESET & VARIABLES
   ============================================ */

:root,
[data-theme="light"] {
  /* ==========================================
     PRIMARY BLUE SCALE (#0066cc equivalent)
     ========================================== */
  --primary-50:  hsl(210, 100%, 97%);
  --primary-100: hsl(210, 100%, 92%);
  --primary-200: hsl(210, 100%, 82%);
  --primary-300: hsl(210, 100%, 70%);
  --primary-400: hsl(210, 100%, 58%);
  --primary-500: hsl(210, 100%, 45%);  /* #0066cc */
  --primary-600: hsl(210, 100%, 38%);
  --primary-700: hsl(210, 100%, 28%);
  --primary-800: hsl(210, 100%, 18%);
  --primary-900: hsl(210, 100%, 12%);

  /* ==========================================
     NEUTRAL SCALE
     ========================================== */
  --neutral-50:  hsl(0, 0%, 98%);
  --neutral-100: hsl(0, 0%, 95%);
  --neutral-200: hsl(0, 0%, 88%);
  --neutral-300: hsl(0, 0%, 78%);
  --neutral-400: hsl(0, 0%, 65%);
  --neutral-500: hsl(0, 0%, 50%);
  --neutral-600: hsl(0, 0%, 38%);
  --neutral-700: hsl(0, 0%, 28%);
  --neutral-800: hsl(0, 0%, 18%);
  --neutral-900: hsl(0, 0%, 10%);

  /* ==========================================
     ADMONITION COLORS
     ========================================== */
  --admonition-note:    var(--primary-500);
  --admonition-info:    hsl(195, 85%, 45%);
  --admonition-warning: hsl(40, 100%, 50%);
  --admonition-danger:  hsl(350, 90%, 50%);
  --admonition-success: hsl(145, 75%, 40%);
  --admonition-bg-opacity: 15%;

  /* ==========================================
     SEMANTIC ALIASES
     ========================================== */
  --bg: var(--neutral-50);
  --text: var(--neutral-800);
  --text-secondary: var(--neutral-600);
  --border: var(--neutral-300);
  --hover: var(--primary-500);
  --header-bg: var(--bg);
  --footer-bg: var(--bg);

  /* ==========================================
     DIAGRAM PALETTE (house-step, etc.)
     ========================================== */
  --diagram-blue:   var(--primary-500);
  --diagram-green:  var(--admonition-success);
  --diagram-grey:   var(--neutral-500);
  --diagram-pink:   hsl(340, 80%, 50%);
  --diagram-orange: hsl(25, 95%, 50%);

  /* ==========================================
     PAYMENT CTA (brand-specific)
     ========================================== */
  --payment-cta:       #0070ba;
  --payment-cta-hover: #005ea6;

  /* ==========================================
     SHARED SHADOWS & OVERLAYS
     ========================================== */
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
  --overlay-scrim: rgba(0, 0, 0, 0.2);
  --overlay-scrim-hover: rgba(0, 0, 0, 0.4);

  /* ==========================================
     FONTS & TYPOGRAPHY
     ========================================== */
  --font-primary: 'Inter', 'Inter Fallback', 'Inter Fallback Android', sans-serif;
  --font-mono: 'JetBrains Mono', 'JetBrains Mono Fallback', 'Inter Fallback Android', monospace;

  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  /* ==========================================
     SPACING
     ========================================== */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;

  /* ==========================================
     BORDER RADIUS
     ========================================== */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
}

/* ============================================
   DARK MODE
   ============================================ */

[data-theme="dark"] {
  --bg: var(--neutral-900);
  --text: var(--neutral-100);
  --text-secondary: var(--neutral-400);
  --border: var(--neutral-700);
  --hover: hsl(210, 100%, 65%);
  --header-bg: var(--bg);
  --footer-bg: var(--bg);
  --admonition-bg-opacity: 20%;
  --overlay-scrim: rgba(255, 255, 255, 0.1);
  --overlay-scrim-hover: rgba(255, 255, 255, 0.2);
}

/* System preference fallback */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --bg: var(--neutral-900);
    --text: var(--neutral-100);
    --text-secondary: var(--neutral-400);
    --border: var(--neutral-700);
    --hover: hsl(210, 100%, 65%);
    --header-bg: var(--bg);
    --footer-bg: var(--bg);
    --admonition-bg-opacity: 20%;
    --overlay-scrim: rgba(255, 255, 255, 0.1);
    --overlay-scrim-hover: rgba(255, 255, 255, 0.2);
  }
}

/* ============================================
   RESET
   ============================================ */

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

/* ============================================
   BASE STYLES
   ============================================ */

html {
  font-size: 106.25%;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-primary);
  font-weight: var(--font-weight-regular);
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.6;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.brand-logo {
  height: 24px;
  width: auto;
  vertical-align: middle;
  margin-right: 4px;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-primary);
  font-weight: var(--font-weight-bold);
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
}

h1 { font-size: 2rem; font-weight: 700; }
h2 { font-size: 1.5rem; font-weight: 700; }
h3 { font-size: 1.5rem; font-weight: 700; }
h4 { font-size: 1.25rem; font-weight: 600; }
h5 { font-size: 1rem; font-weight: 600; }
h6 {
    font-size: .9rem;
    font-weight: 500;
    text-decoration: underline;
    text-underline-offset: 0.3em;
    text-decoration-thickness: 1.5px;
}

h2:first-of-type {
  font-size: 1.1875rem;
  margin-bottom: 2rem;
  font-weight: var(--font-weight-regular);
  border-left: 3px solid var(--hover);
  padding-left: 1rem;
  line-height: 1.6;
}

p {
  margin-bottom: var(--spacing-md);
}

a {
  color: var(--hover);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

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

/* ============================================
   BLOCKQUOTES
   ============================================ */

   blockquote {
        position: relative;
        padding: 1rem 1rem 1rem 3rem;
        color: var(--text-secondary);
        font-style: italic;
        font-size: 1.1rem;
      }

      blockquote::before {
        content: "";
        position: absolute;
        left: 1rem;
        top: 1rem;
        width: 1em;
        height: 2.25em;
        background-image: url("data:image/svg+xml;base64,PHN2ZyB2aWV3Qm94PSIwIDAgNTA4IDExNDMiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyI+CiAgPHBhdGggZmlsbD0iIzAwNjZjYyIgZD0iTSAwLDAgSCA1MDggViA1NzUgSCAwIFoiIC8+CiAgPHBhdGggZmlsbD0iIzAwNjZjYyIgZD0iTSA1MDYsMTE0MiBDIDM3MiwxMTQzIDI0MywxMDg0IDE0OCw5NzcgNTMsODcwIDAsNzI0IDAsNTcyIGggMjUxIGMgMCw4NSAyNywxNjcgNzQsMjI3IDQ4LDYwIDExMiw5MyAxNzksOTMgeiIgLz4KPC9zdmc+ICAgCg==");
        background-size: contain;
        background-repeat: no-repeat;
        opacity: 0.1;
      }

/* ============================================
   TABLES
   ============================================ */

table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--spacing-lg) 0;
  font-size: 0.95rem;
  display: block;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  white-space: nowrap;
}

@media (min-width: 768px) {
  table {
    display: table;
    white-space: normal;
  }
}

thead {
  background-color: color-mix(in srgb, var(--border) 15%, transparent);
}

th {
  text-align: left;
  padding: var(--spacing-sm) var(--spacing-md);
  font-weight: var(--font-weight-semibold);
  border-bottom: 2px solid var(--border);
  color: var(--text);
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

td {
  padding: var(--spacing-sm) var(--spacing-md);
  border-bottom: 1px solid var(--border);
  color: var(--text-secondary);
  vertical-align: top;
}

tbody tr {
  transition: background-color 0.15s ease;
}

tbody tr:hover {
  background-color: color-mix(in srgb, var(--border) 8%, transparent);
}

tbody tr:nth-child(even) {
  background-color: color-mix(in srgb, var(--border) 4%, transparent);
}

tbody tr:nth-child(even):hover {
  background-color: color-mix(in srgb, var(--border) 12%, transparent);
}

tbody tr:last-child td {
  border-bottom: none;
}

tfoot {
  background-color: color-mix(in srgb, var(--border) 10%, transparent);
}

tfoot td {
  padding: var(--spacing-sm) var(--spacing-md);
  border-top: 2px solid var(--border);
  color: var(--text-secondary);
  font-size: 0.9rem;
}

caption {
  caption-side: bottom;
  padding: var(--spacing-sm) 0;
  color: var(--text-secondary);
  font-size: 0.85rem;
  text-align: left;
}

.table-compact th,
.table-compact td {
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: 0.85rem;
}

.table-minimal {
  border: none;
}

.table-minimal th {
  border-bottom: 2px solid var(--border);
  background: none;
}

.table-minimal td {
  border-bottom: none;
}

.table-minimal tbody tr:hover {
  background-color: color-mix(in srgb, var(--border) 6%, transparent);
}

table code {
  font-size: 0.85em;
}

@media (max-width: 768px) {
  table {
    font-size: 0.85rem;
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    white-space: nowrap;
  }

  th, td {
    padding: var(--spacing-xs) var(--spacing-sm);
  }
}

/* ============================================
   LISTS (Main Content Only)
   ============================================ */

main ul,
main ol {
  padding-left: 1.5rem;
  margin-bottom: var(--spacing-md);
}

main ul {
  list-style-type: disc;
}

main ol {
  list-style-type: decimal;
}

main ul ul,
main ol ul {
  list-style-type: circle;
  margin-bottom: 0;
}

main ul ul ul,
main ol ul ul {
  list-style-type: square;
}

main ol ol,
main ul ol {
  list-style-type: lower-alpha;
  margin-bottom: 0;
}

main ol ol ol,
main ul ol ol {
  list-style-type: lower-roman;
}

main li {
  margin-bottom: var(--spacing-xs);
}

main li:last-child {
  margin-bottom: 0;
}

main li > p {
  margin-bottom: var(--spacing-xs);
}

main li > p:last-child {
  margin-bottom: 0;
}

/* ============================================
   CODE & MONOSPACE
   ============================================ */

code,
pre,
kbd,
samp {
  font-family: var(--font-mono);
  font-weight: var(--font-weight-regular);
  font-size: 0.9em;
}

code {
  background-color: var(--border);
  padding: 0.15rem 0.4rem;
  border-radius: var(--radius-sm);
  color: var(--text);
}

pre {
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin-bottom: var(--spacing-md);
}

pre code {
  background-color: transparent;
  padding: 0;
  border-radius: 0;
}

.mono {
  font-family: var(--font-mono);
}

/* ============================================
   HEADER & NAVIGATION
   ============================================ */

header {
  background-color: var(--header-bg);
  border-bottom: 1px solid var(--border);
  padding: 0 var(--spacing-lg);
  width: 100%;
  position: sticky;
  top: 0;
  z-index: 100;
}

nav {
  display: flex;
  font-size: 1rem;
  align-items: center;
  justify-content: space-between;
  max-width: 1200px;
  margin: 0 auto;
  height: 64px;
  position: relative;
}

nav ul {
  list-style: none;
  display: flex;
  align-items: center;
  padding: 0;
  margin: 0;
  gap: var(--spacing-lg);
}

.nav-left {
  flex: 0 0 auto;
}

.nav-center {
  flex: 1 1 auto;
  justify-content: center;
  gap: var(--spacing-xl);
}

.nav-right {
  flex: 0 0 auto;
  gap: var(--spacing-sm);
}

.logo {
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  font-size: 1.1rem;
  letter-spacing: 0.25em;
  color: var(--text);
  transition: color 0.2s ease;
}

.logo:hover,
.nav-center a:hover {
  color: var(--hover);
}

.nav-center a {
  text-decoration: none;
  color: var(--text);
  font-weight: var(--font-weight-regular);
  padding: var(--spacing-xs) 0;
  border-bottom: 2px solid transparent;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.nav-center a:hover {
  border-bottom-color: var(--hover);
}

.nav-icon {
  background: none;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-md);
  cursor: pointer;
  padding: 0.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text);
  width: 38px;
  height: 38px;
  transition: all 0.2s ease;
}

.nav-icon:hover {
  background-color: var(--border);
  border-color: var(--text);
}

.nav-icon svg {
  width: 20px;
  height: 20px;
  display: block;
  stroke: var(--text);
  fill: none;
}

.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  padding: 0.4rem;
  background: none;
  border: 1.5px solid var(--border);
  cursor: pointer;
}

.hamburger span {
  display: block;
  width: 18px;
  height: 2px;
  background-color: var(--text);
  border-radius: 2px;
  transition: all 0.3s ease;
  transform-origin: center;
  flex-shrink: 0;
}

.hamburger--active span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}
.hamburger--active span:nth-child(2) {
  opacity: 0;
}
.hamburger--active span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* ============================================
   FOOTER
   ============================================ */

footer {
  background-color: var(--footer-bg);
  border-top: 1px solid var(--border);
  padding: var(--spacing-lg);
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: auto;
  width: 100%;
}

footer a {
  color: var(--text-secondary);
  text-decoration: underline;
  transition: color 0.2s ease;
}

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

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-lg);
  align-items: center;
}

.footer-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.footer-section-social {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
}

.btn-back-to-top {
  background-color: var(--hover);
  color: var(--bg);
  border: none;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-lg);
  font-size: 0.875rem;
  cursor: pointer;
  transition: all 0.2s ease;
  font-family: var(--font-primary);
  font-weight: var(--font-weight-medium);
}

.btn-back-to-top:hover {
  opacity: 0.85;
  transform: translateY(-2px);
}

.social-link {
  text-decoration: none;
  color: var(--text-secondary);
  display: inline-flex;
  align-items: center;
  transition: color 0.2s ease;
}

.social-link:hover {
  color: var(--hover);
}

.soc-icon {
  width: 20px;
  height: 20px;
  fill: currentColor;
}

.footer-section a:not(.social-link) {
  color: var(--hover);
  text-decoration: none;
}

.footer-section a:not(.social-link):hover {
  text-decoration: underline;
}

.footer-section p {
  margin-bottom: 0;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
    text-align: center;
  }

  .footer-section {
    align-items: center;
  }

  .footer-section-social {
    justify-content: center;
  }

  .btn-back-to-top {
    font-size: 0.8rem;
    padding: var(--spacing-xs) var(--spacing-md);
  }

  .soc-icon {
    width: 18px;
    height: 18px;
  }

  .footer-section p {
    font-size: 0.85rem;
  }
}

/* ============================================
   MAIN CONTENT
   ============================================ */

main {
  max-width: 800px;
  margin: var(--spacing-xl) auto;
  padding: 0 var(--spacing-lg);
  flex: 1;
  width: 100%;
}

/* ============================================
   DROPDOWN MENU
   ============================================ */

.dropdown {
  position: relative;
}

.dropdown-trigger {
  cursor: pointer;
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  background-color: var(--header-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--spacing-sm) 0;
  min-width: 160px;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0;
  opacity: 0;
  visibility: hidden;
  transform-origin: top center;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-lg);
  z-index: 1000;
}

.dropdown-menu li {
  width: 100%;
}

.dropdown-menu a {
  display: block;
  padding: var(--spacing-sm) var(--spacing-lg);
  text-decoration: none;
  color: var(--text);
  font-weight: var(--font-weight-regular);
  border-bottom: none;
  text-align: left;
  transition: background-color 0.2s ease, color 0.2s ease;
  font-size: 0.95rem;
}

.dropdown-menu a:hover {
  background-color: var(--border);
  color: var(--hover);
  border-bottom: none;
}

.dropdown-menu li:first-child a {
  border-radius: var(--radius-md) var(--radius-md) 0 0;
}

.dropdown-menu li:last-child a {
  border-radius: 0 0 var(--radius-md) var(--radius-md);
}

.dropdown--open .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(4px);
}

/* ============================================
   MOBILE RESPONSIVE
   ============================================ */

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

  .nav-center {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background-color: var(--header-bg);
    flex-direction: column;
    padding: var(--spacing-lg);
    gap: var(--spacing-md);
    border-bottom: 1px solid var(--border);
    transform: scaleY(0);
    transform-origin: top center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-md);
    z-index: 99;
  }

  .nav-center--open {
    transform: scaleY(1);
    opacity: 1;
    visibility: visible;
  }

  .nav-center a {
    font-size: 1.1rem;
    padding: var(--spacing-sm) 0;
    width: 100%;
    text-align: left;
  }

  .nav-center li {
    width: 100%;
    text-align: left;
  }

  .nav-right {
    gap: var(--spacing-xs);
  }

  .nav-icon {
    width: 34px;
    height: 34px;
    padding: 0.3rem;
  }

  .nav-icon svg {
    width: 18px;
    height: 18px;
  }

  .hamburger span {
    width: 16px;
    height: 2px;
  }

  .hamburger--active span:nth-child(1) {
    transform: translateY(5px) rotate(45deg);
  }
  .hamburger--active span:nth-child(3) {
    transform: translateY(-5px) rotate(-45deg);
  }

  .nav-left .logo {
    font-size: 0.85rem;
  }

  .dropdown {
    width: 100%;
  }

  .dropdown-trigger {
    justify-content: flex-start;
    width: 100%;
    text-align: left;
    display: flex;
    padding: var(--spacing-sm) 0;
  }

  .dropdown-menu {
    position: static;
    transform: none;
    background-color: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    margin-top: var(--spacing-sm);
    width: 100%;
    box-shadow: none;
    opacity: 0;
    max-height: 0;
    overflow: hidden;
    padding: 0;
    transition: all 0.3s ease;
    visibility: hidden;
  }

  .dropdown--open .dropdown-menu {
    opacity: 1;
    max-height: 300px;
    padding: var(--spacing-sm) 0;
    visibility: visible;
    transform: none;
  }

  .dropdown-menu a {
    text-align: left;
    padding: 0.6rem var(--spacing-lg);
  }

  h1 { font-size: 2rem; }
  h2 { font-size: 1.1875rem; }
  h3 { font-size: 1.35rem; }
  h4 { font-size: 1.15rem; }
}

/* ============================================
   PRINT STYLES
   ============================================ */

@media print {
  header {
    position: static;
    border-bottom: 1px solid #ddd;
  }

  .nav-center,
  .nav-right,
  .hamburger {
    display: none !important;
  }

  body {
    background: white;
    color: black;
  }
}

/* ============================================
   POST CARDS
   ============================================ */

.post-card {
  padding-bottom: var(--spacing-sm);
}

.post-meta {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: .04em;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
  display: flex;
  align-items: center;
  gap: 0.3rem;
  flex-wrap: wrap;
}

.meta-separator {
  color: inherit;
}

.post-meta .author-link {
  color: var(--hover);
  text-decoration: none;
  font-weight: var(--font-weight-medium);
  transition: text-decoration 0.2s ease;
}

.post-meta .author-link:hover {
  text-decoration: underline;
  text-underline-offset: 2px;
}

.post-title {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-sm);
  font-weight: var(--font-weight-semibold);
  letter-spacing: -0.3px;
  line-height: 1.3;
}

.post-title a {
  text-decoration: none;
  color: var(--text);
  transition: color 0.2s ease;
}

.post-title a:hover {
  color: var(--hover);
  text-decoration: none;
  text-underline-offset: 3px;
}

.post-excerpt {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
  line-height: 1.7;
}

.post-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-sm);
}

.post-tag {
  background-color: color-mix(in srgb, var(--border) 30%, transparent);
  color: var(--text-secondary);
  padding: 0.1rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 11px;
  font-weight: var(--font-weight-regular);
  text-transform: lowercase;
  letter-spacing: .04em;
  text-decoration: none;
  transition: all 0.2s ease;
}

.post-tag:hover {
  background-color: var(--hover);
  color: var(--bg);
}

.continue-reading {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: .06em;
  color: var(--hover);
  text-decoration: none;
  display: inline-block;
  margin-bottom: var(--spacing-sm);
  transition: text-decoration 0.2s ease;
}

.post-divider {
  border: 0;
  height: 1px;
  background: color-mix(in srgb, var(--border) 30%, transparent);
  margin: var(--spacing-md) 0 0 0;
}

.post-card:last-of-type .post-divider {
  display: none;
}

@media (max-width: 768px) {
  .post-meta {
    font-size: 0.75rem;
  }

  .post-title {
    font-size: 1.35rem;
  }

  .post-excerpt {
    font-size: 0.95rem;
  }

  .post-tag {
    font-size: 0.6rem;
    padding: 0.05rem 0.6rem;
  }

  .continue-reading {
    font-size: 0.8rem;
  }
}

/* ============================================
   TABBED CONTENT
   ============================================ */

.tab-container {
  max-width: 800px;
  margin: var(--spacing-xl) auto;
  padding: 0;
}

.tab-nav {
  display: flex;
  gap: 4px;
  background: var(--neutral-800);
  border-radius: 5px;
  padding: 0;
  margin-bottom: var(--spacing-lg);
  flex-wrap: wrap;
  align-items: stretch;
  overflow: hidden;
}

.tab-btn {
  border: none;
  padding: var(--spacing-sm) var(--spacing-lg);
  font-family: var(--font-primary);
  font-size: 1.1rem;
  font-weight: var(--font-weight-regular);
  cursor: pointer;
  border-radius: 0;
  transition: all 0.2s ease;
  color: #ffffff;
  background: transparent;
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.tab-btn:hover {
  color: #ffffff;
  background: rgba(255, 255, 255, 0.1);
}

.tab-btn--active {
  background: var(--hover);
  color: #ffffff;
  border-radius: 0;
}

.tab-content {
  display: none;
}

.tab-content--active {
  display: block;
}

.tab-content.user-triggered {
  animation: fadeIn 0.3s ease;
}

.tab-intro {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xl);
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

@media (max-width: 768px) {
  .tab-btn {
    font-size: 1rem;
    padding: var(--spacing-sm) var(--spacing-md);
  }
}

/* ============================================
   TOPIC CARDS
   ============================================ */

.topic-card {
  margin-bottom: var(--spacing-xl);
  padding-bottom: var(--spacing-lg);
  border-bottom: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.topic-card:last-of-type {
  border-bottom: none;
  margin-bottom: 0;
}

.topic-icon {
  margin-bottom: var(--spacing-xs);
  display: flex;
  align-items: center;
}

.topic-icon img {
  max-height: 2.5rem;
  width: auto;
  display: block;
}

.topic-title {
  font-size: 1.5rem;
  font-weight: var(--font-weight-semibold);
  margin: 0 0 var(--spacing-xs) 0;
}

.topic-title a {
  text-decoration: none;
  color: var(--text);
  transition: color 0.2s ease;
}

.topic-title a:hover {
  color: var(--hover);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.topic-excerpt {
  color: var(--text-secondary);
  margin: 0 0 var(--spacing-sm) 0;
  line-height: 1.7;
}

.topic-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--spacing-sm);
}

.topic-tag {
  background-color: var(--border);
  color: var(--text-secondary);
  padding: 0.1rem 0.7rem;
  border-radius: 20px;
  font-size: 0.7rem;
  font-weight: var(--font-weight-medium);
  text-transform: uppercase;
  letter-spacing: 0.03em;
  display: inline-block;
}

.topic-read-time {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-secondary);
  opacity: 0.7;
}

@media (max-width: 768px) {
  .topic-title {
    font-size: 1.25rem;
  }

  .topic-excerpt {
    font-size: 0.95rem;
  }

  .topic-icon img {
    max-height: 2rem;
  }

  .topic-read-time {
    font-size: 0.7rem;
  }
}

/* ============================================
   TOPIC CARDS (continued)
   ============================================ */

.topic-title {
  font-size: 1.5rem;
  font-weight: var(--font-weight-semibold);
  margin: 0 0 var(--spacing-xs) 0;
}

.topic-title a {
  text-decoration: none;
  color: var(--text);
  transition: color 0.2s ease;
}

.topic-title a:hover {
  color: var(--hover);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.topic-excerpt {
  color: var(--text-secondary);
  margin: 0 0 var(--spacing-sm) 0;
  line-height: 1.7;
}

.topic-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--spacing-sm);
}

.topic-tag {
  background-color: var(--border);
  color: var(--text-secondary);
  padding: 0.1rem 0.7rem;
  border-radius: 20px;
  font-size: 0.7rem;
  font-weight: var(--font-weight-medium);
  text-transform: uppercase;
  letter-spacing: 0.03em;
  display: inline-block;
}

.topic-read-time {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-secondary);
  opacity: 0.7;
}

@media (max-width: 768px) {
  .topic-title {
    font-size: 1.25rem;
  }

  .topic-excerpt {
    font-size: 0.95rem;
  }

  .topic-icon img {
    max-height: 2rem;
  }

  .topic-read-time {
    font-size: 0.7rem;
  }
}

/* ============================================
   KEYWORD CLOUD
   ============================================ */

#keyword-cloud {
  display: flex;
  flex-wrap: wrap;
  justify-content: center !important;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-xl);
}

.keyword-button {
  font-family: var(--font-primary);
  font-size: 0.85rem;
  font-weight: var(--font-weight-medium);
  padding: var(--spacing-xs) var(--spacing-md);
  border: 1px solid var(--border);
  border-radius: 20px;
  background-color: transparent;
  color: var(--text);
  cursor: pointer;
  transition: all 0.2s ease;
  margin: 0 4px 6px 0;
}

.keyword-button:hover {
  border-color: var(--hover);
  color: var(--hover);
}

.keyword-button--active {
  background-color: var(--hover);
  border-color: var(--hover);
  color: var(--bg);
}

@media (max-width: 768px) {
  .keyword-button {
    font-size: 0.8rem;
    padding: var(--spacing-xs) var(--spacing-sm);
  }
}

/* ============================================
   ADMONITIONS
   ============================================ */

.admonition {
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
  border-left: 5px solid;
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--admonition-color) var(--admonition-bg-opacity), var(--bg) calc(100% - var(--admonition-bg-opacity)));
  box-shadow: var(--shadow-sm);
  transition: all 0.2s ease;
}

.admonition:hover {
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.08);
}

.admonition-title {
  font-weight: var(--font-weight-regular);
  margin-bottom: 0.75rem;
  font-size: 1.1em;
  color: var(--admonition-color);
}

.admonition-content {
  margin: 0;
}

.admonition-content > :first-child {
  margin-top: 0;
}

.admonition-content > :last-child {
  margin-bottom: 0;
}

.admonition.note {
  --admonition-color: var(--admonition-note);
}

.admonition.info {
  --admonition-color: var(--admonition-info);
}

.admonition.warning {
  --admonition-color: var(--admonition-warning);
}

.admonition.danger,
.admonition.important {
  --admonition-color: var(--admonition-danger);
}

.admonition.success,
.admonition.tip {
  --admonition-color: var(--admonition-success);
}

.admonition-title::before {
  font-size: 1.5em;
  vertical-align: middle;
  line-height: 0;
  margin-right: 0.5rem;
}

.admonition.note .admonition-title::before {
  content: "\270E\FE0E";
}

.admonition.info .admonition-title::before {
  content: "\2139\FE0E";
}

.admonition.warning .admonition-title::before {
  content: "\26A0\FE0E";
}

.admonition.danger .admonition-title::before,
.admonition.important .admonition-title::before {
  content: "\2620\FE0E";
}

.admonition.success .admonition-title::before,
.admonition.tip .admonition-title::before {
  content: "\2714\FE0E";
}

/* ============================================
   POST META TOP (Date and Hit Count)
   ============================================ */

.post-meta-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 0;
  margin-bottom: var(--spacing-lg);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-secondary);
  gap: var(--spacing-sm);
  flex-wrap: nowrap;
  width: 100%;
}

.meta-date {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-shrink: 0;
  white-space: nowrap;
}

.meta-hits {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-shrink: 0;
  white-space: nowrap;
  opacity: 0.7;
  margin-left: auto;
}

.meta-date svg,
.meta-hits svg {
  flex-shrink: 0;
  opacity: 0.7;
  width: 16px;
  height: 16px;
}

.meta-date time {
  color: var(--text-secondary);
}

.meta-hits .hit-number {
  min-width: 1.5rem;
  display: inline-block;
  text-align: center;
}

@media (max-width: 768px) {
  .post-meta-top {
    font-size: 0.75rem;
    padding: 0.5rem 0;
    gap: var(--spacing-xs);
  }

  .meta-date svg,
  .meta-hits svg {
    width: 14px;
    height: 14px;
  }
}

/* ============================================
   FOOTER STYLES
   ============================================ */

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-lg);
  align-items: center;
}

.footer-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.footer-section-social {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
}

.btn-back-to-top {
  background-color: var(--hover);
  color: var(--bg);
  border: none;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-lg);
  font-size: 0.875rem;
  cursor: pointer;
  transition: all 0.2s ease;
  font-family: var(--font-primary);
  font-weight: var(--font-weight-medium);
}

.btn-back-to-top:hover {
  opacity: 0.85;
  transform: translateY(-2px);
}

.social-link {
  text-decoration: none;
  color: var(--text-secondary);
  display: inline-flex;
  align-items: center;
  transition: color 0.2s ease;
}

.social-link:hover {
  color: var(--hover);
}

.soc-icon {
  width: 20px;
  height: 20px;
  fill: currentColor;
}

.footer-section a:not(.social-link) {
  color: var(--hover);
  text-decoration: none;
}

.footer-section a:not(.social-link):hover {
  text-decoration: underline;
}

.footer-section p {
  margin-bottom: 0;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
    text-align: center;
  }

  .footer-section {
    align-items: center;
  }

  .footer-section-social {
    justify-content: center;
  }

  .btn-back-to-top {
    font-size: 0.8rem;
    padding: var(--spacing-xs) var(--spacing-md);
  }

  .soc-icon {
    width: 18px;
    height: 18px;
  }

  .footer-section p {
    font-size: 0.85rem;
  }
}

/* ============================================
   PAYMENT BLOCK
   ============================================ */

.payment-block {
  max-width: 560px;
  margin: 2.5rem auto;
  padding: 3rem 2.5rem;
  text-align: center;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--hover) 8%, var(--bg));
  transition: background 0.3s ease;
}

.payment-block:hover {
  background: color-mix(in srgb, var(--hover) 12%, var(--bg));
}

.price {
  font-size: 3rem;
  font-weight: var(--font-weight-bold);
  margin-bottom: 0.5rem;
}

.payment-desc {
  color: var(--text-secondary);
  margin: 0 0 2rem;
  font-size: 0.95rem;
}

.payment-button {
  display: inline-block;
  width: 100%;
  max-width: 300px;
  padding: 0.8rem 2rem;
  background: var(--payment-cta);
  color: #fff;
  border-radius: var(--radius-md);
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  transition: background 0.2s;
  margin-bottom: 1.5rem;
}

.payment-button:hover {
  background: var(--payment-cta-hover);
  text-decoration: none;
  color: #fff;
}

.free-option {
  margin-bottom: 1.5rem;
}

.free-link {
  color: var(--text-secondary);
  font-size: 0.9rem;
  text-decoration: none;
}

.free-link:hover {
  color: var(--hover);
  text-decoration: underline;
}

.payment-divider {
  border: 0;
  height: 1px;
  background: color-mix(in srgb, var(--border) 25%, transparent);
  margin: 0;
}

.payment-privacy {
  font-size: 0.75rem;
  color: var(--text-secondary);
  opacity: 0.6;
  margin-top: 1.5rem;
}

@media (max-width: 768px) {
  .payment-block {
    padding: 2rem 1.5rem;
    margin: 1.5rem auto;
  }

  .price {
    font-size: 2.4rem;
  }

  .payment-button {
    max-width: 100%;
  }
}

/* ============================================
   BOOK LISTING
   ============================================ */

.book-desktop {
  display: flex;
  gap: var(--spacing-lg);
}

.book-cover {
  flex: 0 0 33%;
}

.book-cover img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-md);
}

.book-mobile {
  display: none;
}

@media (max-width: 768px) {
  .book-desktop {
    display: none;
  }
  .book-mobile {
    display: block;
  }
  .book-cover-mobile {
    max-width: 200px;
    margin-bottom: var(--spacing-md);
    border-radius: var(--radius-md);
  }
}

/* ============================================
   CONTENTS DOTS BUTTON
   ============================================ */

.contents-dots {
  position: fixed;
  top: 45%;
  left: 0;
  transform: translateY(-50%);
  z-index: 100;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 12px 6px;
  color: white;
  text-decoration: none;
  border-radius: 0 8px 8px 0;
  transition: all 0.3s ease;
  gap: 2px;
  min-width: 28px;
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  background: var(--overlay-scrim);
}

.contents-dots:hover {
  background: var(--overlay-scrim-hover);
  padding-right: 10px;
}

.contents-dots svg {
  width: 20px;
  height: 20px;
  stroke: var(--hover);
  opacity: 0.85;
  transition: opacity 0.3s ease;
}

.contents-dots:hover svg {
  opacity: 1;
}

.contents-label {
  font-size: 9px;
  letter-spacing: 1px;
  text-transform: uppercase;
  writing-mode: vertical-rl;
  margin-top: 4px;
}

/* ============================================
   BOOK AD SHORTCODE
   ============================================ */

.book-ad {
  margin: var(--spacing-lg) 0;
  padding: var(--spacing-md);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--border) 5%, var(--bg));
  transition: all 0.2s ease;
}

.book-ad:hover {
  border-color: var(--hover);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

.book-ad-desktop {
  display: flex;
  gap: var(--spacing-md);
  align-items: flex-start;
}

.book-ad-cover {
  flex: 0 0 30%;
}

.book-ad-cover img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  display: block;
}

.book-ad-info {
  flex: 1;
}

.book-ad-title {
  font-size: 1.2rem;
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--spacing-xs);
}

.book-ad-title a {
  color: var(--text);
  text-decoration: none;
}

.book-ad-title a:hover {
  color: var(--hover);
  text-decoration: underline;
}

.book-ad-author {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
}

.book-ad-blurb {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
  line-height: 1.6;
}

.book-ad-cta {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--hover);
  text-decoration: none;
  padding: var(--spacing-xs) var(--spacing-md);
  border: 1px solid var(--hover);
  border-radius: var(--radius-lg);
  transition: all 0.2s ease;
}

.book-ad-cta:hover {
  background-color: var(--hover);
  color: var(--bg);
  text-decoration: none;
}

.book-ad-mobile {
  display: none;
}

.book-ad-cover-mobile {
  max-width: 150px;
  height: auto;
  border-radius: var(--radius-md);
  margin: 0 auto var(--spacing-md);
  display: block;
}

.book-ad-title-mobile {
  font-size: 1.1rem;
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--spacing-xs);
  text-align: center;
}

.book-ad-author-mobile {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
  text-align: center;
}

.book-ad-blurb-mobile {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
  line-height: 1.6;
  text-align: center;
}

.book-ad-cta-mobile {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--hover);
  text-decoration: none;
  padding: var(--spacing-xs) var(--spacing-md);
  border: 1px solid var(--hover);
  border-radius: var(--radius-lg);
  transition: all 0.2s ease;
  text-align: center;
  max-width: 200px;
  margin: 0 auto;
}

.book-ad-cta-mobile:hover {
  background-color: var(--hover);
  color: var(--bg);
  text-decoration: none;
}

@media (max-width: 768px) {
  .book-ad-desktop {
    display: none;
  }

  .book-ad-mobile {
    display: block;
  }

  .book-ad {
    padding: var(--spacing-md);
  }
}

/* ============================================
   FOOTNOTES
   ============================================ */

.footnotes {
  font-size: 0.9rem;
  margin-top: 2em;
  padding-top: 1em;
  font-weight: 400;
}

.footnotes ol {
  padding-left: 1.5em;
}

.footnotes li {
  margin-bottom: 0.5em;
}

.footnote-backref {
  text-decoration: none;
  margin-left: 0.5em;
}

/* ============================================
   KOAN NAVIGATION
   ============================================ */

.koan-nav {
  margin: var(--spacing-lg) 0;
  text-align: center;
}

.koan-nav-inner {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

.koan-nav-btn {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  padding: var(--spacing-sm) var(--spacing-md);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: var(--text);
  background-color: var(--bg);
  transition: all 0.2s ease;
  cursor: pointer;
}

.koan-nav-btn:hover {
  border-color: var(--hover);
  color: var(--hover);
  text-decoration: none;
}

.koan-nav-btn.koan-nav-contents {
  background-color: var(--hover);
  color: var(--bg);
  border-color: var(--hover);
  font-weight: var(--font-weight-medium);
}

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

.koan-nav-btn.koan-nav-disabled {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}

.koan-nav-btn.koan-nav-disabled:hover {
  border-color: var(--border);
  color: var(--text);
  transform: none;
}

.koan-nav-arrow {
  font-size: 0.75rem;
}

.koan-nav-prev .koan-nav-arrow {
  margin-right: var(--spacing-xs);
}

.koan-nav-next .koan-nav-arrow {
  margin-left: var(--spacing-xs);
}

@media (max-width: 768px) {
  .koan-nav-inner {
    gap: var(--spacing-xs);
  }

  .koan-nav-btn {
    font-size: 0.75rem;
    padding: var(--spacing-xs) var(--spacing-sm);
  }

  .koan-nav-btn.koan-nav-prev,
  .koan-nav-btn.koan-nav-next {
    flex: 1;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    max-width: 40%;
  }
}

/* ============================================
   MERMAID RADAR CHART
   ============================================ */

.mermaid svg {
  background: var(--bg) !important;
}

.mermaid svg [class*="radarCurve-"] {
  stroke: var(--hover) !important;
  fill: var(--hover) !important;
  fill-opacity: 0.3 !important;
}

.mermaid svg [class*="radarLegendBox-"] {
  fill: var(--hover) !important;
  stroke: var(--hover) !important;
  fill-opacity: 0.5 !important;
}

.mermaid svg .radarAxisLine {
  stroke: var(--border) !important;
}

.mermaid svg .radarGraticule {
  stroke: var(--border) !important;
  fill: var(--border) !important;
}

.mermaid svg .radarTitle,
.mermaid svg .radarAxisLabel,
.mermaid svg .radarLegendText {
  fill: var(--text) !important;
  color: var(--text) !important;
}

.mermaid svg style {
  display: none !important;
}