/* DutchEngineer Learning Platform Styles
   Brand colors from brandmark:
   - Primary: #6998a5
   - Accent: #7da3ac, #91aeb3, #a5babb
   - Icon: #487886
   - Background: #f9f9f9
   - Text: #3f5a65
*/

:root {
  /* Brand Colors (dark theme defaults) */
  --brand-primary: #6998a5;
  --brand-primary-dark: #487886;
  --brand-primary-light: #7da3ac;
  --brand-accent-1: #91aeb3;
  --brand-accent-2: #a5babb;
  --brand-text: #3f5a65;

  /* Button text on teal backgrounds */
  --on-primary: #f5f2eb;

  /* Dark theme (default) */
  --ink: #12151f;
  --ink-light: #1a1d2e;
  --ink-border: #2a2a2e;
  --ivory: #f5f2eb;
  --ivory-dim: #c9c5bc;
  --ivory-muted: #8a877f;

  /* Semantic colors */
  --teal: #6998a5;
  --teal-dark: #487886;
  --teal-glow: rgba(105, 152, 165, 0.15);
  --gold: #d4a853;
  --gold-glow: rgba(212, 168, 83, 0.15);
  --emerald: #4a9d7c;
  --emerald-glow: rgba(74, 157, 124, 0.15);
  --coral: #e05555;
  --coral-glow: rgba(224, 85, 85, 0.15);

  /* Surface colors (cards, inputs, hover states) */
  --surface: #111112;
  --surface-hover: #1e1e1f;

  /* Code block colors */
  --code-bg: #1a1a1b;
  --code-inline-bg: #141416;
  --code-inline-color: #e05555;

  color-scheme: dark light;

  /* Typography */
  --font-display: "Crimson Pro", Georgia, serif;
  --font-body: "Sora", -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", monospace;

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

  /* Layout */
  --sidebar-width: 17.5rem;
  --toc-width: 12.5rem;
  --content-max-width: 50rem;
  --header-height: 3.75rem;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;

  /* Border radius */
  --radius-sm: 4px;
  --radius-md: 0.5rem;
  --radius-lg: 12px;
  --radius: 0.75rem;

  /* Semantic aliases (used across all apps) */
  --color-accent: var(--teal);
  --color-text: var(--ivory);
  --color-text-muted: var(--ivory-muted);
  --color-border: var(--ink-border);
  --color-surface: var(--surface);

  /* Button disabled states */
  --btn-disabled-bg: #333;
  --btn-disabled-text: #666;

  /* Gold hover */
  --gold-hover: #e0b44e;
}

/* Light theme — system preference or manual override */
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --ink: #f9f9f9;
    --ink-light: #ffffff;
    --ink-border: #c8d0d4;
    --ivory: #3f5a65;
    --ivory-dim: #4a6872;
    --ivory-muted: #6b8591;
    --surface: #ffffff;
    --surface-hover: #f0f2f4;
    --on-primary: #ffffff;
    --brand-primary-light: #487886;
    --brand-accent-1: #5a8a96;
    --brand-accent-2: #6b9aa5;
    --teal: #6998a5;
    --teal-dark: #487886;
    --teal-glow: rgba(105, 152, 165, 0.1);
    --gold: #b8922e;
    --gold-glow: rgba(184, 146, 46, 0.1);
    --emerald: #3d8a6a;
    --emerald-glow: rgba(61, 138, 106, 0.1);
    --coral: #d04444;
    --coral-glow: rgba(208, 68, 68, 0.1);
    --code-bg: #f0f2f4;
    --code-inline-bg: #e4e8eb;
    --code-inline-color: #d04444;
  }
}

[data-theme="light"] {
  --ink: #f9f9f9;
  --ink-light: #ffffff;
  --ink-border: #c8d0d4;
  --ivory: #3f5a65;
  --ivory-dim: #4a6872;
  --ivory-muted: #6b8591;
  --surface: #ffffff;
  --surface-hover: #f0f2f4;
  --on-primary: #ffffff;
  --brand-primary-light: #487886;
  --brand-accent-1: #5a8a96;
  --brand-accent-2: #6b9aa5;
  --teal: #6998a5;
  --teal-dark: #487886;
  --teal-glow: rgba(105, 152, 165, 0.1);
  --gold: #b8922e;
  --gold-glow: rgba(184, 146, 46, 0.1);
  --emerald: #3d8a6a;
  --emerald-glow: rgba(61, 138, 106, 0.1);
  --coral: #d04444;
  --coral-glow: rgba(208, 68, 68, 0.1);
  --code-bg: #f0f2f4;
  --code-inline-bg: #e4e8eb;
  --code-inline-color: #d04444;
}

/* Skip link */
.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  padding: 0.5rem 1rem;
  background: var(--teal);
  color: var(--ivory);
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  text-decoration: none;
  z-index: 9999;
  transition: top 0.1s;
}

.skip-link:focus,
.skip-link:focus-visible {
  top: 1rem;
}

/* Reset */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

/* Focus visible — keyboard navigation */
:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 3px;
  border-radius: 2px;
}

html {
  font-size: 1rem;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  background: var(--ink);
  color: var(--ivory);
  line-height: 1.6;
  font-size: 1rem;
  min-height: 100vh;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.3;
  color: var(--ivory);
}

h1 {
  font-size: 2.25rem;
  margin-bottom: var(--space-lg);
}
h2 {
  font-size: 1.75rem;
  margin-bottom: var(--space-md);
  margin-top: var(--space-2xl);
}
h3 {
  font-size: 1.375rem;
  margin-bottom: var(--space-md);
  margin-top: var(--space-xl);
}
h4 {
  font-size: 1.125rem;
  margin-bottom: var(--space-sm);
  margin-top: var(--space-lg);
}

p {
  margin-bottom: var(--space-md);
  color: var(--ivory-dim);
}

a {
  color: var(--teal);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--teal-dark);
  text-decoration: underline;
}

strong {
  color: var(--ivory);
}

/* Top Navigation */
.topnav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-xl);
  height: var(--header-height);
  background: var(--ink-light);
  border-bottom: 1px solid var(--ink-border);
  position: sticky;
  top: 0;
  z-index: 100;
  width: 100%;
  box-sizing: border-box;
  overflow: visible;
  z-index: 300;
  position: relative;
}

.topnav-left {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.topnav-logo {
  display: flex;
  align-items: center;
  text-decoration: none;
}

.topnav-logo img {
  height: 1.5rem;
  width: auto;
}

.topnav-center {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.topnav-right {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  flex-shrink: 0;
}

/* Search */
.topnav-search-btn {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.375rem 0.75rem;
  background: var(--surface);
  border: 1px solid var(--ink-border);
  border-radius: 0.375rem;
  color: var(--ivory-muted);
  font-family: var(--font-body);
  font-size: 0.8125rem;
  cursor: pointer;
  transition: all 0.15s ease;
}

.topnav-search-btn:hover {
  border-color: var(--ivory-muted);
  color: var(--ivory);
}

.topnav-search-btn svg {
  flex-shrink: 0;
}

.search-label {
  opacity: 0.7;
}

.search-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  z-index: 200;
  display: flex;
  justify-content: center;
  padding-top: 8rem;
}

.search-overlay.hidden {
  display: none;
}

.search-modal {
  width: 100%;
  max-width: 36rem;
  max-height: 28rem;
  background: var(--ink-light);
  border: 1px solid var(--ink-border);
  border-radius: 0.75rem;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  box-shadow: 0 1.5rem 3rem rgba(0, 0, 0, 0.4);
}

.search-header {
  display: flex;
  align-items: center;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--ink-border);
  gap: 0.5rem;
}

.search-input {
  flex: 1;
  background: none;
  border: none;
  color: var(--ivory);
  font-family: var(--font-body);
  font-size: 1rem;
  outline: none;
}

.search-input::placeholder {
  color: var(--ivory-muted);
}

.search-close {
  background: var(--surface);
  border: 1px solid var(--ink-border);
  border-radius: 0.25rem;
  color: var(--ivory-muted);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  padding: 0.125rem 0.375rem;
  cursor: pointer;
}

.search-results {
  overflow-y: auto;
  padding: 0.5rem;
}

.search-result-item {
  display: block;
  padding: 0.75rem 1rem;
  border-radius: 0.5rem;
  text-decoration: none;
  transition: background 0.1s ease;
}

.search-result-item:hover {
  background: var(--surface);
  text-decoration: none;
}

.search-result-title {
  font-weight: 600;
  color: var(--ivory);
  font-size: 0.9375rem;
  margin-bottom: 0.25rem;
}

.search-result-excerpt {
  font-size: 0.8125rem;
  color: var(--ivory-muted);
  line-height: 1.5;
}

.search-result-excerpt mark {
  background: rgba(212, 168, 83, 0.3);
  color: var(--ivory);
  border-radius: 0.125rem;
  padding: 0 0.125rem;
}

.search-empty {
  padding: 2rem;
  text-align: center;
  color: var(--ivory-muted);
  font-size: 0.875rem;
}

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

  .search-modal {
    margin: 0 1rem;
  }
}

.hidden {
  display: none;
}

.theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--ivory-dim);
  padding: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast);
}

.theme-toggle svg {
  width: 1.5rem;
  height: 1.5rem;
}

.theme-toggle:hover {
  color: var(--ivory);
}

.topnav-auth {
  font-size: 1.125rem;
  font-weight: 500;
}

.profile-menu {
  position: relative;
}

.profile-btn {
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.375rem;
  border-radius: 50%;
  color: var(--ivory-dim);
  display: flex;
  align-items: center;
  justify-content: center;
  transition:
    color 0.15s,
    background 0.15s;
}

.profile-btn svg {
  width: 1.375rem;
  height: 1.375rem;
}

.profile-btn:hover {
  color: var(--ivory);
  background: rgba(255, 255, 255, 0.07);
}

.profile-dropdown {
  display: none;
  position: absolute;
  top: calc(100% + 0.5rem);
  right: 0;
  background: var(--ink-light);
  border: 1px solid var(--ink-border);
  border-radius: var(--radius-md);
  min-width: 10rem;
  overflow: hidden;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
  z-index: 200;
}

.profile-dropdown.open {
  display: block;
}

.profile-dropdown-item {
  display: block;
  width: 100%;
  background: none;
  border: none;
  padding: 0.625rem 1rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  color: var(--ivory-dim);
  text-align: left;
  cursor: pointer;
  transition:
    background 0.15s,
    color 0.15s;
}

.profile-dropdown-item:hover {
  background: rgba(255, 255, 255, 0.06);
  color: var(--ivory);
}

.profile-dropdown-upgrade {
  color: var(--teal);
}

.profile-dropdown-upgrade:hover {
  color: var(--teal);
}

.profile-dropdown-divider {
  height: 1px;
  background: var(--ink-border);
  margin: 0.25rem 0;
}

.topnav-link {
  padding: var(--space-sm) var(--space-md);
  color: var(--ivory-dim);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.topnav-link:hover {
  color: var(--ivory);
  background: var(--ink);
  text-decoration: none;
}

.topnav-link.active {
  color: var(--teal);
  background: var(--teal-glow);
}

/* Layout */
.layout {
  display: flex;
  min-height: calc(100vh - var(--header-height));
}

.main-content {
  flex: 1;
  min-height: calc(100vh - var(--header-height));
}

/* Legacy sidebar (kept for reference) */
.sidebar {
  width: var(--sidebar-width);
  background: var(--ink-light);
  border-right: 1px solid var(--ink-border);
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  overflow-y: auto;
  z-index: 100;
}

.content-wrapper {
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: var(--space-2xl) var(--space-xl);
}

/* Header */
.site-header {
  padding: var(--space-lg);
  border-bottom: 1px solid var(--ink-border);
}

.site-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  text-decoration: none;
}

.site-logo img {
  height: 1.75rem;
  width: auto;
}

.site-logo span {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--ivory);
}

/* Navigation */
.nav-section {
  padding: var(--space-lg);
  border-bottom: 1px solid var(--ink-border);
}

.nav-section-title {
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ivory-muted);
  margin-bottom: var(--space-md);
}

/* Sidebar Progress */
.sidebar-progress {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.sidebar-progress .progress-bar {
  height: 0.375rem;
  background: var(--ink-border);
  border-radius: 3px;
}

.sidebar-progress .progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--teal), var(--emerald));
  border-radius: 3px;
}

.progress-label {
  font-size: 0.75rem;
  color: var(--ivory-muted);
}

/* Nav icons */
.nav-icon {
  margin-right: var(--space-sm);
  font-size: 1rem;
}

.nav-list {
  list-style: none;
}

.nav-item {
  margin-bottom: var(--space-xs);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  color: var(--ivory-dim);
  text-decoration: none;
  font-size: 0.875rem;
  transition: all var(--transition-fast);
}

.nav-link:hover {
  background: var(--ink);
  color: var(--ivory);
  text-decoration: none;
}

.nav-link.active {
  background: var(--teal-glow);
  color: var(--teal);
}

.nav-link-icon {
  width: 1.125rem;
  height: 1.125rem;
  opacity: 0.7;
}

/* Course navigation (nested) */
.nav-part {
  margin-bottom: var(--space-md);
}

.nav-part-title {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--ivory);
  padding: var(--space-sm) 0;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-part-title::after {
  content: "▾";
  font-size: 0.75rem;
  color: var(--ivory-muted);
  transition: transform var(--transition-fast);
}

.nav-part.collapsed .nav-part-title::after {
  transform: rotate(-90deg);
}

.nav-weeks {
  list-style: none;
  margin-left: var(--space-md);
}

.nav-part.collapsed .nav-weeks {
  display: none;
}

.nav-week-link {
  display: block;
  padding: var(--space-xs) var(--space-sm);
  font-size: 0.8125rem;
  color: var(--ivory-muted);
  border-left: 2px solid var(--ink-border);
  transition: all var(--transition-fast);
}

.nav-week-link:hover {
  color: var(--ivory);
  border-left-color: var(--teal);
  text-decoration: none;
}

.nav-week-link.active {
  color: var(--teal);
  border-left-color: var(--teal);
}

.nav-week-link.completed {
  color: var(--emerald);
}

.nav-week-link.completed::before {
  content: "✓ ";
}

/* Progress indicator */
.progress-bar {
  height: 4px;
  background: var(--ink-border);
  border-radius: 2px;
  overflow: hidden;
  position: relative;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--teal), var(--emerald));
  border-radius: 2px;
  transition: width var(--transition-normal);
}

.progress-text {
  position: absolute;
  right: 0;
  top: -1.25rem;
  font-size: 0.75rem;
  color: var(--ivory-muted);
}

/* Cards */
.card {
  background: var(--ink-light);
  border: 1px solid var(--ink-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: all var(--transition-fast);
  text-decoration: none;
}

.card:hover {
  border-color: var(--teal);
  box-shadow: 0 4px 20px var(--teal-glow);
}

.card-title {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--ivory);
  margin-bottom: var(--space-sm);
}

.card-meta {
  font-size: 0.8125rem;
  color: var(--ivory-muted);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(17.5rem, 1fr));
  gap: var(--space-lg);
}

/* Lesson content */
.lesson-header {
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid var(--ink-border);
}

.lesson-breadcrumb {
  font-size: 0.8125rem;
  color: var(--ivory-muted);
  margin-bottom: var(--space-md);
}

.lesson-breadcrumb a {
  color: var(--ivory-muted);
}

.lesson-breadcrumb a:hover {
  color: var(--teal);
}

.lesson-title {
  font-size: 2rem;
  margin-bottom: var(--space-md);
}

.lesson-meta {
  display: flex;
  gap: var(--space-lg);
  font-size: 0.875rem;
  color: var(--ivory-muted);
}

.lesson-meta-item {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.lesson-reading-time {
  font-size: 0.8125rem;
  color: var(--ivory-muted);
  margin-top: var(--space-xs);
  margin-bottom: var(--space-2xl);
}

/* Lesson content styling */
.lesson-content {
  line-height: 1.8;
}

.lesson-content h2 {
  margin-top: var(--space-3xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--ink-border);
}

.lesson-content h2:first-child {
  margin-top: 0;
  padding-top: 0;
  border-top: none;
}

.lesson-content ul,
.lesson-content ol {
  margin-bottom: var(--space-md);
  padding-left: var(--space-xl);
  color: var(--ivory-dim);
}

.lesson-content li {
  margin-bottom: var(--space-sm);
}

.lesson-content blockquote {
  border-left: 3px solid var(--teal);
  padding-left: var(--space-lg);
  margin: var(--space-lg) 0;
  color: var(--ivory-muted);
  font-style: italic;
}

/* Admonitions */
.admonition {
  border-radius: var(--radius-md);
  padding: var(--space-md) var(--space-lg);
  margin: var(--space-lg) 0;
  border-left: 4px solid;
}

.admonition-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  margin-bottom: var(--space-sm);
}

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

.admonition-note {
  background: rgba(105, 152, 165, 0.08);
  border-color: var(--teal);
}

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

.admonition-tip {
  background: rgba(74, 157, 124, 0.08);
  border-color: var(--emerald);
}

.admonition-tip .admonition-title {
  color: var(--emerald);
}

.admonition-warning {
  background: rgba(212, 168, 83, 0.08);
  border-color: var(--gold);
}

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

/* Code blocks */
pre {
  background: var(--ink);
  border: 1px solid var(--ink-border);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  overflow-x: auto;
  margin: var(--space-lg) 0;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.5;
}

code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--ink);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-sm);
  color: var(--teal);
}

pre code {
  background: none;
  padding: 0;
  color: var(--ivory);
}

/* Callout boxes */
.callout {
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  margin: var(--space-lg) 0;
  border-left: 4px solid;
}

.callout-title {
  font-weight: 600;
  margin-bottom: var(--space-sm);
  color: var(--ivory);
}

.callout-content {
  color: var(--ivory-dim);
}

.callout-content p:last-child {
  margin-bottom: 0;
}

.callout-info {
  background: var(--teal-glow);
  border-left-color: var(--teal);
}

.callout-warning {
  background: var(--gold-glow);
  border-left-color: var(--gold);
}

.callout-tip {
  background: var(--emerald-glow);
  border-left-color: var(--emerald);
}

.callout-checkpoint {
  background: var(--emerald-glow);
  border-left-color: var(--emerald);
}

.callout-code {
  background: var(--teal-glow);
  border-left-color: var(--teal-dark);
}

/* Math blocks */
.math-block {
  background: var(--ink);
  border: 1px solid var(--ink-border);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  margin: var(--space-lg) 0;
  overflow-x: auto;
  text-align: center;
  color: var(--ivory);
}

/* Code tabs */
.code-tabs {
  margin: var(--space-lg) 0;
  border: 1px solid var(--ink-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.code-tabs-nav {
  display: flex;
  background: var(--ink-light);
  border-bottom: 1px solid var(--ink-border);
}

.code-tab {
  padding: var(--space-sm) var(--space-lg);
  background: none;
  border: none;
  color: var(--ivory-muted);
  font-family: var(--font-body);
  font-size: 0.875rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.code-tab:hover {
  color: var(--ivory);
  background: var(--ink);
}

.code-tab.active {
  color: var(--teal);
  background: var(--ink);
  border-bottom: 2px solid var(--teal);
}

.code-tabs-content pre {
  margin: 0;
  border: none;
  border-radius: 0;
}

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-lg) 0;
}

th,
td {
  padding: var(--space-sm) var(--space-md);
  text-align: left;
  border: 1px solid var(--ink-border);
}

th {
  background: var(--ink-light);
  font-weight: 600;
  color: var(--ivory);
}

td {
  color: var(--ivory-dim);
}

tr:hover td {
  background: var(--ink-light);
}

/* Badges */
.badge {
  display: inline-block;
  padding: var(--space-xs) var(--space-sm);
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-radius: var(--radius-sm);
}

.badge-teal {
  background: var(--teal-glow);
  color: var(--teal);
}

.badge-gold {
  background: var(--gold-glow);
  color: var(--gold);
}

.badge-emerald {
  background: var(--emerald-glow);
  color: var(--emerald);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition-fast);
}

.btn-primary {
  background: linear-gradient(135deg, var(--teal-dark), var(--teal));
  color: var(--ivory);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px var(--teal-glow);
  text-decoration: none;
  color: var(--ivory);
}

.btn-secondary {
  background: var(--ink-light);
  border: 1px solid var(--ink-border);
  color: var(--ivory);
}

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

/* Lesson navigation (prev/next) */
.lesson-nav {
  display: flex;
  justify-content: space-between;
  margin-top: var(--space-3xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--ink-border);
}

.lesson-nav-link {
  display: flex;
  flex-direction: column;
  padding: var(--space-md);
  border: 1px solid var(--ink-border);
  border-radius: var(--radius-md);
  text-decoration: none;
  max-width: 45%;
  transition: all var(--transition-fast);
}

.lesson-nav-link:hover {
  border-color: var(--teal);
  text-decoration: none;
}

.lesson-nav-label {
  font-size: 0.75rem;
  color: var(--ivory-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.lesson-nav-title {
  color: var(--ivory);
  font-weight: 500;
}

.lesson-nav-next {
  text-align: right;
  margin-left: auto;
}

/* Breadcrumb */
.breadcrumb {
  display: flex;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--ivory-muted);
  margin-bottom: 1rem;
}

.breadcrumb a {
  color: var(--teal);
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
}

/* Footer */
.site-footer {
  padding: var(--space-lg);
  border-top: 1px solid var(--ink-border);
  margin-top: auto;
  text-align: center;
  font-size: 0.8125rem;
  color: var(--ivory-muted);
}

.site-footer a {
  color: var(--ivory-muted);
  text-decoration: none;
}

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

/* Responsive */
@media (max-width: 1024px) {
  .topnav {
    padding: 0 var(--space-md);
  }

  .topnav-center {
    display: none;
  }

  .topnav-right {
    gap: var(--space-sm);
  }

  .topnav-auth {
    font-size: 0.6875rem;
    padding: var(--space-xs) var(--space-xs);
  }

  .content-wrapper {
    padding: var(--space-lg);
  }
}

@media (min-width: 1025px) {
  .topnav-right {
    min-width: 6.25rem;
    justify-content: flex-end;
  }
}

@media (max-width: 640px) {
  .topnav-logo img {
    height: 1.125rem;
  }

  .topnav-auth {
    font-size: 0.75rem;
  }

  h1 {
    font-size: 1.75rem;
  }
  h2 {
    font-size: 1.375rem;
  }
  h3 {
    font-size: 1.125rem;
  }

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

  .lesson-nav {
    flex-direction: column;
    gap: var(--space-md);
  }

  .lesson-nav-link {
    max-width: 100%;
  }

  .lesson-nav-next {
    text-align: left;
  }
}

/* Mobile menu toggle (for hamburger menu on mobile) */
.menu-toggle {
  display: none;
  padding: 0.75rem;
  background: none;
  border: none;
  color: var(--ivory);
  font-size: 1.5rem;
  cursor: pointer;
}

@media (max-width: 1024px) {
  .menu-toggle {
    display: block;
  }
}

/* Utilities */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.text-center {
  text-align: center;
}
.text-muted {
  color: var(--ivory-muted);
}
.mt-lg {
  margin-top: var(--space-lg);
}
.mb-lg {
  margin-bottom: var(--space-lg);
}

/* Settings page */
.settings-page {
  max-width: 40rem;
  margin: 3rem auto;
  padding: 0 1.5rem 4rem;
}

.settings-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 2rem;
}

.settings-card {
  background: var(--surface);
  border: 1px solid var(--ink-border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
}

.settings-section-title {
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ivory-muted);
  margin-top: 2rem;
  margin-bottom: 0.5rem;
}

.settings-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 0;
}

.settings-row + .settings-row {
  border-top: 1px solid var(--ink-border);
}

.settings-field {
  padding: 0.75rem 0;
}

.settings-field + .settings-field {
  border-top: 1px solid var(--ink-border);
}

.settings-label {
  display: block;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--ivory-muted);
  margin-bottom: 0.5rem;
}

.settings-value {
  font-size: 0.875rem;
  color: var(--ivory);
}

.settings-input-row {
  display: flex;
  gap: 0.625rem;
}

.settings-input {
  flex: 1;
  background: var(--ink);
  border: 1px solid var(--ink-border);
  border-radius: var(--radius-md);
  padding: 0.5rem 0.75rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  color: var(--ivory);
  outline: none;
  transition: border-color 0.15s;
}

.settings-input:focus {
  border-color: var(--teal);
}

.settings-save-btn {
  background: var(--teal-dark);
  color: var(--ivory);
  border: none;
  border-radius: var(--radius-md);
  padding: 0.5rem 1rem;
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.15s;
}

.settings-save-btn:hover {
  background: var(--teal);
}

.settings-save-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.settings-secondary-btn {
  background: none;
  border: 1px solid var(--ink-border);
  border-radius: var(--radius-md);
  padding: 0.5rem 1rem;
  font-family: var(--font-body);
  font-size: 0.8125rem;
  color: var(--ivory-muted);
  cursor: pointer;
  transition:
    border-color 0.15s,
    color 0.15s;
}

.settings-secondary-btn:hover {
  border-color: var(--teal);
  color: var(--ivory);
}

.settings-secondary-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.settings-feedback {
  font-size: 0.8125rem;
  margin-top: 0.375rem;
}

.settings-feedback-ok {
  color: var(--emerald);
}

.settings-feedback-error {
  color: var(--coral);
}

.theme-options {
  display: flex;
  gap: 0.5rem;
}

.theme-option {
  background: none;
  border: 1px solid var(--ink-border);
  border-radius: var(--radius-md);
  padding: 0.375rem 0.875rem;
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--ivory-muted);
  cursor: pointer;
  transition:
    border-color 0.15s,
    color 0.15s,
    background 0.15s;
}

.theme-option:hover {
  border-color: var(--teal);
  color: var(--ivory);
}

.theme-option.active {
  border-color: var(--teal);
  background: rgba(105, 152, 165, 0.12);
  color: var(--ivory);
}

.settings-card-upgrade {
  border-color: rgba(105, 152, 165, 0.25);
}

.settings-upgrade-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.settings-plan-label {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.settings-plan-desc {
  font-size: 0.8125rem;
  color: var(--ivory-muted);
  line-height: 1.5;
}

.btn-upgrade {
  background: var(--teal-dark);
  color: var(--ivory);
  border: none;
  border-radius: var(--radius-md);
  padding: 0.625rem 1.25rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  white-space: nowrap;
  transition: background 0.2s;
}

/* Upgrade page */
.upgrade-page {
  padding: 3rem 1.5rem 5rem;
}

.upgrade-inner {
  max-width: 52rem;
  margin: 0 auto;
}

.upgrade-hero {
  text-align: center;
  margin-bottom: 3rem;
}

.upgrade-heading {
  font-family: var(--font-display);
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--ivory);
  margin-bottom: 0.75rem;
}

.upgrade-subheading {
  font-size: 1.0625rem;
  color: var(--ivory-muted);
  max-width: 36rem;
  margin: 0 auto;
  line-height: 1.6;
}

.upgrade-plans {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  align-items: start;
  margin-bottom: 4rem;
}

.upgrade-plan {
  background: var(--surface);
  border: 1px solid var(--ink-border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  position: relative;
}

.upgrade-plan-pro {
  border-color: var(--teal);
  background: linear-gradient(
    135deg,
    rgba(105, 152, 165, 0.08) 0%,
    var(--surface) 100%
  );
}

.upgrade-plan-badge {
  position: absolute;
  top: -0.75rem;
  left: 50%;
  transform: translateX(-50%);
  background: var(--teal-dark);
  color: var(--ivory);
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.25rem 0.875rem;
  border-radius: 2rem;
  white-space: nowrap;
}

.upgrade-plan-header {
  margin-bottom: 1.25rem;
}

.upgrade-plan-name {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ivory-muted);
  display: block;
  margin-bottom: 0.5rem;
}

.upgrade-plan-price {
  display: flex;
  align-items: baseline;
  gap: 0.375rem;
}

.upgrade-price-amount {
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--ivory);
  transition: all 0.2s;
}

.upgrade-price-period {
  font-size: 0.875rem;
  color: var(--ivory-muted);
}

.upgrade-billing-toggle {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.upgrade-billing-btn {
  flex: 1;
  padding: 0.375rem 0.75rem;
  background: none;
  border: 1px solid var(--ink-border);
  border-radius: var(--radius-md);
  color: var(--ivory-muted);
  font-family: var(--font-body);
  font-size: 0.8125rem;
  cursor: pointer;
  transition: all 0.15s;
}

.upgrade-billing-btn.active {
  border-color: var(--teal);
  color: var(--ivory);
  background: var(--teal-glow);
}

.upgrade-billing-save {
  font-size: 0.6875rem;
  color: var(--emerald);
  margin-left: 0.25rem;
}

.upgrade-features {
  list-style: none;
  padding: 0;
  margin: 0 0 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
}

.upgrade-feature {
  display: flex;
  align-items: flex-start;
  gap: 0.625rem;
  font-size: 0.875rem;
  color: var(--ivory-dim);
  line-height: 1.4;
}

.upgrade-feature-locked {
  color: var(--ivory-muted);
  opacity: 0.6;
}

.upgrade-feature-check {
  color: var(--emerald);
  font-size: 0.875rem;
  flex-shrink: 0;
  margin-top: 0.05rem;
}

.upgrade-feature-x {
  color: var(--ivory-muted);
  font-size: 0.875rem;
  flex-shrink: 0;
  margin-top: 0.05rem;
}

.upgrade-plan-cta {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.625rem;
}

.upgrade-btn {
  display: block;
  width: 100%;
  padding: 0.75rem;
  background: var(--teal-dark);
  color: var(--ivory);
  border: none;
  border-radius: var(--radius-md);
  font-family: var(--font-body);
  font-size: 0.9375rem;
  font-weight: 600;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.2s;
}

.upgrade-btn:hover {
  background: var(--teal);
  color: var(--ivory);
}

.upgrade-current-plan {
  font-size: 0.875rem;
  color: var(--ivory-muted);
  padding: 0.75rem;
}

.upgrade-plan-note {
  font-size: 0.75rem;
  color: var(--ivory-muted);
  text-align: center;
}

/* FAQ */
.upgrade-faq {
  max-width: 36rem;
  margin: 0 auto;
}

.upgrade-faq-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--ivory);
  margin-bottom: 1.25rem;
}

.upgrade-faq-item {
  border-top: 1px solid var(--ink-border);
  padding: 1rem 0;
}

.upgrade-faq-item:last-child {
  border-bottom: 1px solid var(--ink-border);
}

.upgrade-faq-q {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--ivory);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.upgrade-faq-q::after {
  content: "+";
  color: var(--ivory-muted);
  font-size: 1.125rem;
  flex-shrink: 0;
}

details[open] .upgrade-faq-q::after {
  content: "−";
}

.upgrade-faq-a {
  font-size: 0.875rem;
  color: var(--ivory-muted);
  line-height: 1.6;
  margin-top: 0.75rem;
}

@media (max-width: 640px) {
  .upgrade-plans {
    grid-template-columns: 1fr;
  }

  .upgrade-heading {
    font-size: 1.75rem;
  }
}

.btn-upgrade:hover {
  background: var(--teal);
}

/* ── Site Footer ─────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--color-border, var(--ink-border));
  padding: 1.25rem 2rem;
  margin-top: auto;
}

.site-footer-inner {
  max-width: 72rem;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
}

.site-footer-bottom {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.site-footer-copy {
  font-size: 0.75rem;
  color: var(--ivory-muted);
  opacity: 0.6;
}

.site-footer-brand {
  display: flex;
  align-items: center;
  text-decoration: none;
}

.site-footer-brand img {
  height: 1.5rem;
  width: auto;
  opacity: 0.7;
}

.site-footer-brand:hover img {
  opacity: 1;
}

.site-footer-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.site-footer-links a {
  font-size: 0.8125rem;
  color: var(--ivory-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.site-footer-links a:hover {
  color: var(--ivory);
}

/* Newsletter partial */
.newsletter-embed {
  margin-top: 3rem;
  padding-top: 3rem;
  border-top: 1px solid var(--ink-border);
}

.newsletter-embed h2 {
  font-family: var(--font-body);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--ivory);
  margin-bottom: 0.5rem;
}

.newsletter-embed > p {
  color: var(--ivory-dim);
  font-size: 1rem;
  margin-bottom: 1.25rem;
}

.newsletter-form {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.newsletter-form input[type="email"] {
  flex: 1;
  min-width: 200px;
  padding: 0.625rem 1rem;
  background: var(--surface);
  border: 1px solid var(--ink-border);
  border-radius: 0.375rem;
  color: var(--ivory);
  font-family: var(--font-body);
  font-size: 0.9375rem;
}

.newsletter-form input[type="email"]::placeholder {
  color: var(--ivory-muted);
}

.newsletter-form button {
  padding: 0.625rem 1.5rem;
  background: var(--teal);
  border: none;
  border-radius: 0.375rem;
  color: #fff;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition-fast);
}

.newsletter-form button:hover {
  background: var(--teal-dark);
}

.newsletter-message {
  margin-top: 0.75rem;
  font-size: 0.9rem;
}

.newsletter-message.success {
  color: var(--emerald);
}
.newsletter-message.error {
  color: #e05555;
}