/* ============================================================
   SourceFlow.Net — Documentation Website Design System
   ============================================================ */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=JetBrains+Mono:wght@400;500;600&display=swap');

/* --- CSS Custom Properties --- */
:root {
  /* Core palette */
  --sf-bg-primary:     #0d1117;
  --sf-bg-secondary:   #161b22;
  --sf-bg-tertiary:    #1c2128;
  --sf-bg-card:        rgba(22, 27, 34, 0.75);
  --sf-bg-elevated:    #21262d;
  --sf-border:         rgba(48, 54, 61, 0.6);
  --sf-border-bright:  rgba(88, 166, 255, 0.25);

  /* Accent colors */
  --sf-blue:           #58a6ff;
  --sf-blue-bright:    #79c0ff;
  --sf-blue-dim:       #1f6feb;
  --sf-green:          #3fb950;
  --sf-green-bright:   #56d364;
  --sf-purple:         #bc8cff;
  --sf-orange:         #f0883e;
  --sf-red:            #f85149;
  --sf-yellow:         #e3b341;
  --sf-cyan:           #39d2c0;

  /* Text colors */
  --sf-text-primary:   #e6edf3;
  --sf-text-secondary: #8b949e;
  --sf-text-tertiary:  #6e7681;
  --sf-text-link:      #58a6ff;

  /* Gradients */
  --sf-gradient-hero:  linear-gradient(135deg, #0d1117 0%, #161b22 40%, #0d2137 100%);
  --sf-gradient-blue:  linear-gradient(135deg, #1f6feb 0%, #58a6ff 100%);
  --sf-gradient-green: linear-gradient(135deg, #238636 0%, #3fb950 100%);
  --sf-gradient-card:  linear-gradient(145deg, rgba(22,27,34,0.9) 0%, rgba(13,17,23,0.95) 100%);

  /* Typography */
  --sf-font-sans:  'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --sf-font-mono:  'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;

  /* Spacing */
  --sf-space-xs:   0.25rem;
  --sf-space-sm:   0.5rem;
  --sf-space-md:   1rem;
  --sf-space-lg:   1.5rem;
  --sf-space-xl:   2rem;
  --sf-space-2xl:  3rem;
  --sf-space-3xl:  4rem;

  /* Radius */
  --sf-radius-sm:  6px;
  --sf-radius-md:  10px;
  --sf-radius-lg:  16px;
  --sf-radius-xl:  24px;

  /* Shadows */
  --sf-shadow-sm:   0 1px 3px rgba(0,0,0,0.3);
  --sf-shadow-md:   0 4px 12px rgba(0,0,0,0.4);
  --sf-shadow-lg:   0 8px 32px rgba(0,0,0,0.5);
  --sf-shadow-glow: 0 0 20px rgba(88,166,255,0.15);

  /* Transitions */
  --sf-transition:       all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --sf-transition-fast:  all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --sf-transition-slow:  all 0.4s cubic-bezier(0.4, 0, 0.2, 1);

  /* Layout */
  --sf-max-width:  1280px;
  --sf-nav-height: 64px;
  --sf-sidebar-width: 280px;

  /* Nav Backgrounds */
  --sf-bg-nav:          rgba(13, 17, 23, 0.85);
  --sf-bg-nav-scrolled: rgba(13, 17, 23, 0.95);
}

/* --- Light Theme Variables --- */
:root[data-theme="light"] {
  /* Core palette */
  --sf-bg-primary:     #ffffff;
  --sf-bg-secondary:   #f6f8fa;
  --sf-bg-tertiary:    #eaeef2;
  --sf-bg-card:        rgba(246, 248, 250, 0.75);
  --sf-bg-elevated:    #eff2f5;
  --sf-border:         rgba(208, 215, 222, 0.6);
  --sf-border-bright:  rgba(9, 105, 218, 0.25);

  /* Accent colors adjusted for light background */
  --sf-blue:           #0969da;
  --sf-blue-bright:    #218bff;
  --sf-blue-dim:       #0969da;
  --sf-green:          #1a7f37;
  --sf-green-bright:   #2da44e;
  --sf-purple:         #8250df;
  --sf-orange:         #bc4c00;
  --sf-red:            #cf222e;
  --sf-yellow:         #9a6700;
  --sf-cyan:           #05988a;

  /* Text colors */
  --sf-text-primary:   #24292f;
  --sf-text-secondary: #57606a;
  --sf-text-tertiary:  #8c959f;
  --sf-text-link:      #0969da;

  /* Gradients */
  --sf-gradient-hero:  linear-gradient(135deg, #ffffff 0%, #f6f8fa 40%, #ddf4ff 100%);
  --sf-gradient-blue:  linear-gradient(135deg, #0969da 0%, #218bff 100%);
  --sf-gradient-green: linear-gradient(135deg, #1a7f37 0%, #2da44e 100%);
  --sf-gradient-card:  linear-gradient(145deg, rgba(246,248,250,0.9) 0%, rgba(255,255,255,0.95) 100%);

  /* Shadows */
  --sf-shadow-sm:   0 1px 3px rgba(0,0,0,0.06);
  --sf-shadow-md:   0 4px 12px rgba(0,0,0,0.08);
  --sf-shadow-lg:   0 8px 32px rgba(0,0,0,0.12);
  --sf-shadow-glow: 0 0 20px rgba(9,105,218,0.08);

  /* Nav Backgrounds */
  --sf-bg-nav:          rgba(255, 255, 255, 0.85);
  --sf-bg-nav-scrolled: rgba(255, 255, 255, 0.95);
}

/* --- Reset & Base --- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--sf-nav-height) + 1rem);
}

body {
  font-family: var(--sf-font-sans);
  background: var(--sf-bg-primary);
  color: var(--sf-text-primary);
  line-height: 1.7;
  font-size: 15px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: var(--sf-text-link);
  text-decoration: none;
  transition: var(--sf-transition-fast);
}
a:hover {
  color: var(--sf-blue-bright);
}

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

h1, h2, h3, h4, h5, h6 {
  line-height: 1.3;
  font-weight: 700;
  color: var(--sf-text-primary);
}
h1 { font-size: 2.75rem; letter-spacing: -0.03em; }
h2 { font-size: 2rem; letter-spacing: -0.02em; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.2rem; }

p { color: var(--sf-text-secondary); }

code, pre {
  font-family: var(--sf-font-mono);
}

::selection {
  background: var(--sf-blue-dim);
  color: #fff;
}

/* --- Container --- */
.container {
  width: 100%;
  max-width: var(--sf-max-width);
  margin: 0 auto;
  padding: 0 var(--sf-space-xl);
}

/* ============================================================
   NAVIGATION
   ============================================================ */
.sf-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--sf-nav-height);
  background: var(--sf-bg-nav);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid var(--sf-border);
  z-index: 1000;
  transition: var(--sf-transition);
}

.sf-nav.scrolled {
  background: var(--sf-bg-nav-scrolled);
  box-shadow: var(--sf-shadow-md);
}

.sf-nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--sf-max-width);
  margin: 0 auto;
  padding: 0 var(--sf-space-xl);
}

.sf-nav__logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 800;
  font-size: 1.2rem;
  color: var(--sf-text-primary);
  letter-spacing: -0.02em;
}
.sf-nav__logo img {
  width: 32px;
  height: 32px;
}
.sf-nav__logo:hover { color: var(--sf-blue); }
.sf-nav__logo-dot {
  color: var(--sf-blue);
}
.sf-nav__logo-license {
  font-size: 0.65rem;
  font-weight: 700;
  padding: 0.1rem 0.35rem;
  background: rgba(88, 166, 255, 0.1);
  border: 1px solid rgba(88, 166, 255, 0.2);
  border-radius: 4px;
  color: var(--sf-blue);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-left: 0.15rem;
}
:root[data-theme="light"] .sf-nav__logo-license {
  background: rgba(9, 105, 218, 0.08);
  border-color: rgba(9, 105, 218, 0.15);
  color: var(--sf-blue);
}

.sf-nav__links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
}
.sf-nav__links a {
  display: flex;
  align-items: center;
  padding: 0.45rem 0.85rem;
  border-radius: var(--sf-radius-sm);
  color: var(--sf-text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  transition: var(--sf-transition-fast);
}
.sf-nav__links a:hover,
.sf-nav__links a.active {
  color: var(--sf-text-primary);
  background: var(--sf-bg-elevated);
}
.sf-nav__links a.active {
  color: var(--sf-blue);
}

.sf-nav__actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* GitHub Badge (in nav) */
.sf-github-badge {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  background: var(--sf-bg-elevated);
  border: 1px solid var(--sf-border);
  border-radius: var(--sf-radius-md);
  font-size: 0.8rem;
  color: var(--sf-text-secondary);
  transition: var(--sf-transition);
  text-decoration: none;
}
.sf-github-badge:hover {
  border-color: var(--sf-border-bright);
  color: var(--sf-text-primary);
  box-shadow: var(--sf-shadow-glow);
}
.sf-github-badge svg {
  width: 18px;
  height: 18px;
  fill: var(--sf-text-primary);
}
.sf-github-badge__stat {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}
.sf-github-badge__stat svg {
  width: 14px;
  height: 14px;
  fill: var(--sf-text-tertiary);
}

/* Mobile hamburger */
.sf-nav__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.sf-nav__hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--sf-text-secondary);
  border-radius: 2px;
  transition: var(--sf-transition);
}

/* ============================================================
   HERO SECTION
   ============================================================ */
.sf-hero {
  position: relative;
  min-height: calc(100vh - var(--sf-nav-height));
  display: flex;
  align-items: center;
  padding-top: var(--sf-nav-height);
  background: var(--sf-gradient-hero);
  overflow: hidden;
}

.sf-hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(88,166,255,0.1) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 80% 60%, rgba(63,185,80,0.06) 0%, transparent 50%);
  pointer-events: none;
}

/* Animated grid overlay */
.sf-hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(88,166,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(88,166,255,0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
  animation: gridFloat 20s linear infinite;
}
@keyframes gridFloat {
  0%   { transform: translateY(0); }
  100% { transform: translateY(60px); }
}

.sf-hero__content {
  position: relative;
  z-index: 1;
  max-width: 720px;
}

.sf-hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 1rem;
  background: rgba(88,166,255,0.08);
  border: 1px solid rgba(88,166,255,0.2);
  border-radius: 999px;
  color: var(--sf-blue);
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: var(--sf-space-lg);
  letter-spacing: 0.03em;
}
.sf-hero__badge-dot {
  width: 6px;
  height: 6px;
  background: var(--sf-green);
  border-radius: 50%;
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.sf-hero__title {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 900;
  letter-spacing: -0.04em;
  line-height: 1.1;
  margin-bottom: var(--sf-space-lg);
  background: linear-gradient(135deg, #e6edf3 30%, #58a6ff 70%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
:root[data-theme="light"] .sf-hero__title {
  background: none;
  -webkit-background-clip: initial;
  background-clip: initial;
  -webkit-text-fill-color: initial;
  color: var(--sf-text-primary);
}
.sf-hero__license {
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--sf-text-secondary);
  -webkit-text-fill-color: var(--sf-text-secondary);
  margin-left: 1.5rem;
  display: inline-block;
  vertical-align: middle;
  letter-spacing: normal;
}
:root[data-theme="light"] .sf-hero__license {
  -webkit-text-fill-color: var(--sf-text-secondary);
  color: var(--sf-text-secondary);
}

.sf-hero__desc {
  font-size: 1.15rem;
  color: var(--sf-text-secondary);
  margin-bottom: var(--sf-space-2xl);
  line-height: 1.8;
  max-width: 600px;
}

.sf-hero__actions {
  display: flex;
  gap: var(--sf-space-md);
  flex-wrap: wrap;
}

/* ============================================================
   BUTTONS
   ============================================================ */
.sf-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.7rem 1.5rem;
  border-radius: var(--sf-radius-md);
  font-size: 0.9rem;
  font-weight: 600;
  font-family: var(--sf-font-sans);
  border: none;
  cursor: pointer;
  transition: var(--sf-transition);
  text-decoration: none;
}
.sf-btn svg {
  width: 18px;
  height: 18px;
}
.sf-btn--primary {
  background: var(--sf-gradient-blue);
  color: #fff;
  box-shadow: 0 2px 12px rgba(31,111,235,0.35);
}
.sf-btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(31,111,235,0.5);
  color: #fff;
}
.sf-btn--secondary {
  background: var(--sf-bg-elevated);
  color: var(--sf-text-primary);
  border: 1px solid var(--sf-border);
}
.sf-btn--secondary:hover {
  border-color: var(--sf-border-bright);
  background: var(--sf-bg-tertiary);
  color: var(--sf-text-primary);
}

/* ============================================================
   STATS BAR
   ============================================================ */
.sf-stats-bar {
  background: var(--sf-bg-secondary);
  border-top: 1px solid var(--sf-border);
  border-bottom: 1px solid var(--sf-border);
  padding: var(--sf-space-lg) 0;
}
.sf-stats-bar__inner {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sf-space-2xl);
  flex-wrap: wrap;
}
.sf-stat-card {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.6rem 1.2rem;
  background: var(--sf-bg-card);
  border: 1px solid var(--sf-border);
  border-radius: var(--sf-radius-md);
  transition: var(--sf-transition);
}
.sf-stat-card:hover {
  border-color: var(--sf-border-bright);
  box-shadow: var(--sf-shadow-glow);
  transform: translateY(-1px);
}
.sf-stat-card__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--sf-radius-sm);
  background: var(--sf-bg-elevated);
}
.sf-stat-card__icon svg {
  width: 20px;
  height: 20px;
  fill: var(--sf-text-primary);
}
.sf-stat-card__info {
  display: flex;
  flex-direction: column;
}
.sf-stat-card__label {
  font-size: 0.7rem;
  color: var(--sf-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
}
.sf-stat-card__value {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--sf-text-primary);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.sf-stat-card__value .sf-stat-item {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}
.sf-stat-card__value .sf-stat-item svg {
  width: 14px;
  height: 14px;
}
.sf-stat-card__value .sf-stat-item--stars svg { fill: var(--sf-yellow); }
.sf-stat-card__value .sf-stat-item--forks svg { fill: var(--sf-text-tertiary); }
.sf-stat-card__value .sf-stat-item--downloads svg { fill: var(--sf-green); }
.sf-stat-card__value .sf-stat-tag {
  font-size: 0.7rem;
  padding: 0.15rem 0.5rem;
  background: rgba(88,166,255,0.1);
  border: 1px solid rgba(88,166,255,0.2);
  border-radius: 999px;
  color: var(--sf-blue);
  font-weight: 600;
}

/* ============================================================
   SECTIONS
   ============================================================ */
.sf-section {
  padding: var(--sf-space-3xl) 0;
}
.sf-section--alt {
  background: var(--sf-bg-secondary);
}

.sf-section__header {
  text-align: center;
  margin-bottom: var(--sf-space-3xl);
}
.sf-section__header h2 {
  margin-bottom: var(--sf-space-md);
}
.sf-section__header p {
  font-size: 1.05rem;
  max-width: 600px;
  margin: 0 auto;
}
.sf-section__label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--sf-blue);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--sf-space-sm);
}

/* ============================================================
   FEATURE CARDS
   ============================================================ */
.sf-features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--sf-space-lg);
}

.sf-feature-card {
  position: relative;
  padding: var(--sf-space-xl);
  background: var(--sf-gradient-card);
  border: 1px solid var(--sf-border);
  border-radius: var(--sf-radius-lg);
  transition: var(--sf-transition);
  overflow: hidden;
}
.sf-feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--sf-gradient-blue);
  opacity: 0;
  transition: var(--sf-transition);
}
.sf-feature-card:hover {
  border-color: var(--sf-border-bright);
  transform: translateY(-4px);
  box-shadow: var(--sf-shadow-lg), var(--sf-shadow-glow);
}
.sf-feature-card:hover::before {
  opacity: 1;
}
.sf-feature-card__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: var(--sf-radius-md);
  background: rgba(88,166,255,0.1);
  margin-bottom: var(--sf-space-md);
  font-size: 1.5rem;
}
.sf-feature-card__icon--green  { background: rgba(63,185,80,0.1); }
.sf-feature-card__icon--purple { background: rgba(188,140,255,0.1); }
.sf-feature-card__icon--orange { background: rgba(240,136,62,0.1); }
.sf-feature-card__icon--cyan   { background: rgba(57,210,192,0.1); }
.sf-feature-card__icon--yellow { background: rgba(227,179,65,0.1); }

.sf-feature-card h3 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}
.sf-feature-card p {
  font-size: 0.9rem;
  line-height: 1.7;
}

/* ============================================================
   PACKAGE CARDS
   ============================================================ */
.sf-packages-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
  gap: var(--sf-space-lg);
}
.sf-package-card {
  padding: var(--sf-space-xl);
  background: var(--sf-bg-card);
  border: 1px solid var(--sf-border);
  border-radius: var(--sf-radius-lg);
  backdrop-filter: blur(8px);
  transition: var(--sf-transition);
}
.sf-package-card:hover {
  border-color: var(--sf-border-bright);
  transform: translateY(-3px);
  box-shadow: var(--sf-shadow-md);
}
.sf-package-card__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--sf-space-md);
}
.sf-package-card__name {
  font-size: 1rem;
  font-weight: 700;
  font-family: var(--sf-font-mono);
  color: var(--sf-blue);
}
.sf-package-card__version {
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  background: rgba(63,185,80,0.1);
  border: 1px solid rgba(63,185,80,0.2);
  border-radius: 999px;
  color: var(--sf-green);
  font-weight: 600;
}
.sf-package-card p {
  font-size: 0.9rem;
  margin-bottom: var(--sf-space-md);
}
.sf-package-card__install {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.85rem;
  background: var(--sf-bg-primary);
  border: 1px solid var(--sf-border);
  border-radius: var(--sf-radius-sm);
  font-family: var(--sf-font-mono);
  font-size: 0.8rem;
  color: var(--sf-text-secondary);
}
.sf-package-card__install .sf-prompt {
  color: var(--sf-green);
  user-select: none;
}

/* ============================================================
   CODE BLOCKS
   ============================================================ */
.sf-code-block {
  /* Force dark theme color system inside code blocks regardless of parent theme */
  --sf-bg-primary:     #0d1117;
  --sf-bg-secondary:   #161b22;
  --sf-bg-tertiary:    #1c2128;
  --sf-border:         rgba(48, 54, 61, 0.6);
  --sf-border-bright:  rgba(88, 166, 255, 0.25);
  --sf-blue:           #58a6ff;
  --sf-blue-bright:    #79c0ff;
  --sf-green:          #3fb950;
  --sf-green-bright:   #56d364;
  --sf-purple:         #bc8cff;
  --sf-orange:         #f0883e;
  --sf-red:            #f85149;
  --sf-yellow:         #e3b341;
  --sf-cyan:           #39d2c0;
  --sf-text-primary:   #e6edf3;
  --sf-text-secondary: #8b949e;
  --sf-text-tertiary:  #6e7681;

  position: relative;
  margin: var(--sf-space-lg) 0;
  border-radius: var(--sf-radius-md);
  overflow: hidden;
  border: 1px solid var(--sf-border);
}
.sf-code-block__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.6rem 1rem;
  background: var(--sf-bg-tertiary);
  border-bottom: 1px solid var(--sf-border);
}
.sf-code-block__lang {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--sf-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.sf-code-block__dots {
  display: flex;
  gap: 6px;
}
.sf-code-block__dots span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}
.sf-code-block__dots span:nth-child(1) { background: #f85149; }
.sf-code-block__dots span:nth-child(2) { background: #e3b341; }
.sf-code-block__dots span:nth-child(3) { background: #3fb950; }

.sf-code-block__copy {
  position: absolute;
  top: 0.55rem;
  right: 0.75rem;
  padding: 0.3rem 0.6rem;
  background: var(--sf-bg-elevated);
  border: 1px solid var(--sf-border);
  border-radius: var(--sf-radius-sm);
  color: var(--sf-text-tertiary);
  font-size: 0.7rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--sf-transition-fast);
  font-family: var(--sf-font-sans);
  z-index: 2;
}
.sf-code-block__copy:hover {
  color: var(--sf-text-primary);
  border-color: var(--sf-border-bright);
}

.sf-code-block pre {
  padding: var(--sf-space-lg);
  background: var(--sf-bg-primary);
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.8;
  tab-size: 4;
}
.sf-code-block pre code {
  color: var(--sf-text-primary);
}

/* Syntax highlighting colors */
.token.comment, .token.prolog, .token.doctype, .token.cdata {
  color: var(--sf-text-tertiary);
  font-style: italic;
}
.token.keyword { color: var(--sf-purple); font-weight: 600; }
.token.string, .token.attr-value { color: var(--sf-cyan); }
.token.number { color: var(--sf-orange); }
.token.boolean { color: var(--sf-orange); }
.token.function { color: var(--sf-blue-bright); }
.token.class-name { color: var(--sf-green-bright); }
.token.operator { color: var(--sf-red); }
.token.punctuation { color: var(--sf-text-tertiary); }
.token.property { color: var(--sf-blue); }
.token.namespace { color: var(--sf-green); }
.token.builtin { color: var(--sf-yellow); }
.token.attr-name { color: var(--sf-blue); }
.token.tag { color: var(--sf-green); }
.token.selector { color: var(--sf-green-bright); }

/* Manual syntax highlight helper */
.code-kw  { color: var(--sf-purple); font-weight: 600; }
.code-type { color: var(--sf-green-bright); }
.code-str { color: var(--sf-cyan); }
.code-cmt { color: var(--sf-text-tertiary); font-style: italic; }
.code-fn  { color: var(--sf-blue-bright); }
.code-num { color: var(--sf-orange); }
.code-op  { color: var(--sf-red); }
.code-ns  { color: var(--sf-green); }

/* ============================================================
   ARCHITECTURE DIAGRAM
   ============================================================ */
.sf-arch-diagram {
  padding: var(--sf-space-2xl);
  background: var(--sf-bg-card);
  border: 1px solid var(--sf-border);
  border-radius: var(--sf-radius-lg);
  overflow-x: auto;
}
.sf-arch-diagram pre {
  font-family: var(--sf-font-mono);
  font-size: 0.8rem;
  line-height: 1.6;
  color: var(--sf-text-secondary);
  white-space: pre;
}

/* ============================================================
   BOOK SECTION
   ============================================================ */
.sf-book {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--sf-space-2xl);
  align-items: center;
  padding: var(--sf-space-2xl);
  background: var(--sf-gradient-card);
  border: 1px solid var(--sf-border);
  border-radius: var(--sf-radius-lg);
}
.sf-book__cover {
  width: 200px;
  border-radius: var(--sf-radius-md);
  box-shadow: var(--sf-shadow-lg);
  transition: var(--sf-transition);
}
.sf-book__cover:hover {
  transform: scale(1.03) rotate(-1deg);
}
.sf-book__info h3 {
  font-size: 1.3rem;
  margin-bottom: 0.5rem;
}
.sf-book__info p {
  margin-bottom: var(--sf-space-md);
}

/* ============================================================
   SIDEBAR (Documentation pages)
   ============================================================ */
.sf-docs-layout {
  display: grid;
  grid-template-columns: var(--sf-sidebar-width) 1fr;
  gap: var(--sf-space-2xl);
  padding-top: calc(var(--sf-nav-height) + var(--sf-space-2xl));
  min-height: 100vh;
}

.sf-sidebar {
  position: sticky;
  top: calc(var(--sf-nav-height) + var(--sf-space-xl));
  height: fit-content;
  max-height: calc(100vh - var(--sf-nav-height) - 3rem);
  overflow-y: auto;
  padding: var(--sf-space-md) 0;
  scrollbar-width: thin;
  scrollbar-color: var(--sf-border) transparent;
}
.sf-sidebar::-webkit-scrollbar {
  width: 4px;
}
.sf-sidebar::-webkit-scrollbar-track {
  background: transparent;
}
.sf-sidebar::-webkit-scrollbar-thumb {
  background: var(--sf-border);
  border-radius: 4px;
}

.sf-sidebar__section {
  margin-bottom: var(--sf-space-lg);
}
.sf-sidebar__title {
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--sf-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 0.3rem 0.75rem;
  margin-bottom: 0.25rem;
}
.sf-sidebar__links {
  list-style: none;
}
.sf-sidebar__links a {
  display: block;
  padding: 0.4rem 0.75rem;
  padding-left: 1rem;
  font-size: 0.85rem;
  color: var(--sf-text-secondary);
  border-radius: var(--sf-radius-sm);
  border-left: 2px solid transparent;
  transition: var(--sf-transition-fast);
}
.sf-sidebar__links a:hover {
  color: var(--sf-text-primary);
  background: rgba(88,166,255,0.05);
}
.sf-sidebar__links a.active {
  color: var(--sf-blue);
  background: rgba(88,166,255,0.08);
  border-left-color: var(--sf-blue);
  font-weight: 600;
}

/* --- Content area --- */
.sf-content {
  max-width: 850px;
  padding-bottom: var(--sf-space-3xl);
}
.sf-content h1 {
  padding-bottom: var(--sf-space-md);
  border-bottom: 1px solid var(--sf-border);
  margin-bottom: var(--sf-space-xl);
}
.sf-content h2 {
  margin-top: var(--sf-space-2xl);
  margin-bottom: var(--sf-space-md);
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--sf-border);
}
.sf-content h3 {
  margin-top: var(--sf-space-xl);
  margin-bottom: var(--sf-space-sm);
}
.sf-content p {
  margin-bottom: var(--sf-space-md);
}
.sf-content ul, .sf-content ol {
  padding-left: 1.5rem;
  margin-bottom: var(--sf-space-md);
  color: var(--sf-text-secondary);
}
.sf-content li {
  margin-bottom: 0.4rem;
}
.sf-content li strong {
  color: var(--sf-text-primary);
}

/* Inline code */
.sf-content code:not(pre code) {
  padding: 0.15rem 0.45rem;
  background: var(--sf-bg-elevated);
  border: 1px solid var(--sf-border);
  border-radius: 4px;
  font-size: 0.82rem;
  color: var(--sf-orange);
}

/* Tables */
.sf-content table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--sf-space-lg) 0;
  font-size: 0.88rem;
}
.sf-content th {
  text-align: left;
  padding: 0.75rem 1rem;
  background: var(--sf-bg-tertiary);
  border: 1px solid var(--sf-border);
  color: var(--sf-text-primary);
  font-weight: 600;
}
.sf-content td {
  padding: 0.65rem 1rem;
  border: 1px solid var(--sf-border);
  color: var(--sf-text-secondary);
}
.sf-content tr:hover td {
  background: rgba(88,166,255,0.03);
}

/* Tip/Note/Warning boxes */
.sf-callout {
  padding: var(--sf-space-md) var(--sf-space-lg);
  border-radius: var(--sf-radius-md);
  margin: var(--sf-space-lg) 0;
  border-left: 4px solid;
}
.sf-callout--tip {
  background: rgba(63,185,80,0.06);
  border-color: var(--sf-green);
}
.sf-callout--note {
  background: rgba(88,166,255,0.06);
  border-color: var(--sf-blue);
}
.sf-callout--warning {
  background: rgba(240,136,62,0.06);
  border-color: var(--sf-orange);
}
.sf-callout__title {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--sf-text-primary);
  margin-bottom: 0.25rem;
}
.sf-callout p {
  font-size: 0.88rem;
  margin-bottom: 0;
}

/* ============================================================
   FOOTER
   ============================================================ */
.sf-footer {
  background: var(--sf-bg-secondary);
  border-top: 1px solid var(--sf-border);
  padding: var(--sf-space-3xl) 0 var(--sf-space-xl);
}
.sf-footer__grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: var(--sf-space-2xl);
  margin-bottom: var(--sf-space-2xl);
}
.sf-footer__brand p {
  font-size: 0.88rem;
  margin-top: 0.5rem;
  max-width: 300px;
}
.sf-footer__col h4 {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--sf-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--sf-space-md);
}
.sf-footer__col ul {
  list-style: none;
}
.sf-footer__col a {
  display: block;
  padding: 0.3rem 0;
  font-size: 0.88rem;
  color: var(--sf-text-secondary);
}
.sf-footer__col a:hover {
  color: var(--sf-text-primary);
}
.sf-footer__bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--sf-space-lg);
  border-top: 1px solid var(--sf-border);
  font-size: 0.8rem;
  color: var(--sf-text-tertiary);
}

/* ============================================================
   SCROLL ANIMATIONS
   ============================================================ */
.sf-reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}
.sf-reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1024px) {
  .sf-docs-layout {
    grid-template-columns: 1fr;
  }
  .sf-sidebar {
    display: none;
    position: fixed;
    top: var(--sf-nav-height);
    left: 0;
    width: var(--sf-sidebar-width);
    height: calc(100vh - var(--sf-nav-height));
    background: var(--sf-bg-secondary);
    border-right: 1px solid var(--sf-border);
    z-index: 999;
    padding: var(--sf-space-lg);
  }
  .sf-sidebar.open {
    display: block;
  }
  .sf-footer__grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  :root {
    --sf-nav-height: 56px;
  }
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  .container {
    padding: 0 var(--sf-space-md);
  }
  .sf-nav__links {
    display: none;
    position: fixed;
    top: var(--sf-nav-height);
    left: 0;
    right: 0;
    background: var(--sf-bg-secondary);
    border-bottom: 1px solid var(--sf-border);
    flex-direction: column;
    padding: var(--sf-space-md);
    box-shadow: var(--sf-shadow-lg);
  }
  .sf-nav__links.open {
    display: flex;
  }
  .sf-nav__hamburger {
    display: flex;
  }
  .sf-github-badge .sf-github-badge__stat:not(:first-child) {
    display: none;
  }
  .sf-hero__title {
    font-size: 2.2rem;
  }
  .sf-features-grid {
    grid-template-columns: 1fr;
  }
  .sf-packages-grid {
    grid-template-columns: 1fr;
  }
  .sf-book {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .sf-book__cover {
    margin: 0 auto;
  }
  .sf-stats-bar__inner {
    gap: var(--sf-space-md);
  }
  .sf-footer__grid {
    grid-template-columns: 1fr;
  }
  .sf-footer__bottom {
    flex-direction: column;
    gap: 0.5rem;
    text-align: center;
  }
}

/* ============================================================
   FLOW DIAGRAM (CSS-based for landing page)
   ============================================================ */
.sf-flow {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  flex-wrap: wrap;
  padding: var(--sf-space-xl);
}
.sf-flow__node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
  padding: 0.8rem 1.2rem;
  background: var(--sf-bg-card);
  border: 1px solid var(--sf-border);
  border-radius: var(--sf-radius-md);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--sf-text-primary);
  transition: var(--sf-transition);
}
.sf-flow__node:hover {
  border-color: var(--sf-blue);
  box-shadow: var(--sf-shadow-glow);
  transform: translateY(-2px);
}
.sf-flow__node-icon {
  font-size: 1.4rem;
}
.sf-flow__arrow {
  color: var(--sf-text-tertiary);
  font-size: 1.5rem;
  padding: 0 0.5rem;
  animation: arrowPulse 2s ease-in-out infinite;
}
@keyframes arrowPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; transform: translateX(3px); }
}

/* ============================================================
   ROADMAP TABLE
   ============================================================ */
.sf-roadmap-table {
  overflow-x: auto;
}
.sf-roadmap-table table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
}
.sf-roadmap-table th {
  text-align: left;
  padding: 0.75rem 1rem;
  background: var(--sf-bg-tertiary);
  border: 1px solid var(--sf-border);
  color: var(--sf-text-primary);
  font-weight: 600;
  white-space: nowrap;
}
.sf-roadmap-table td {
  padding: 0.65rem 1rem;
  border: 1px solid var(--sf-border);
  color: var(--sf-text-secondary);
}
.sf-roadmap-table .sf-pkg-name {
  font-family: var(--sf-font-mono);
  color: var(--sf-blue);
  font-weight: 600;
}

/* ============================================================
   MOBILE NAV OVERLAY
   ============================================================ */
.sf-nav-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 998;
}
.sf-nav-overlay.active {
  display: block;
}

/* Quick tabs for pages */
.sf-page-tabs {
  display: flex;
  gap: var(--sf-space-xs);
  margin-bottom: var(--sf-space-xl);
  border-bottom: 1px solid var(--sf-border);
  padding-bottom: 0;
  overflow-x: auto;
}
.sf-page-tabs a {
  padding: 0.6rem 1rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--sf-text-secondary);
  border-bottom: 2px solid transparent;
  white-space: nowrap;
  transition: var(--sf-transition-fast);
}
.sf-page-tabs a:hover {
  color: var(--sf-text-primary);
}
.sf-page-tabs a.active {
  color: var(--sf-blue);
  border-bottom-color: var(--sf-blue);
}

/* ============================================================
   BADGE INLINE STYLE (for NuGet/version badges)
   ============================================================ */
.sf-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}
.sf-badge--blue {
  background: rgba(88,166,255,0.12);
  color: var(--sf-blue);
  border: 1px solid rgba(88,166,255,0.2);
}
.sf-badge--green {
  background: rgba(63,185,80,0.12);
  color: var(--sf-green);
  border: 1px solid rgba(63,185,80,0.2);
}
.sf-badge--purple {
  background: rgba(188,140,255,0.12);
  color: var(--sf-purple);
  border: 1px solid rgba(188,140,255,0.2);
}

/* ============================================================
   THEME TOGGLE BUTTON
   ============================================================ */
.sf-theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: var(--sf-radius-md);
  border: 1px solid var(--sf-border);
  background: var(--sf-bg-elevated);
  color: var(--sf-text-secondary);
  cursor: pointer;
  transition: var(--sf-transition-fast);
  padding: 0;
}
.sf-theme-toggle:hover {
  border-color: var(--sf-border-bright);
  color: var(--sf-text-primary);
  box-shadow: var(--sf-shadow-glow);
}
.sf-theme-toggle svg {
  width: 18px;
  height: 18px;
  stroke: currentColor;
}

/* Light/Dark visibility logic */
:root[data-theme="light"] .sf-theme-toggle .sun {
  display: none;
}
:root:not([data-theme="light"]) .sf-theme-toggle .moon {
  display: none;
}