:root {
  color-scheme: light;
  --tn-bg: #f6f8fb;
  --tn-surface: #ffffff;
  --tn-surface-soft: #f0f4f7;
  --tn-text: #142033;
  --tn-muted: #5d6b7e;
  --tn-border: #dce3ea;
  --tn-accent: #087f5b;
  --tn-accent-strong: #06694b;
  --tn-accent-soft: #e8f6f0;
  --tn-navy: #12345b;
  --tn-code: #0d1726;
  --tn-danger: #b42318;
  --tn-warning: #9a6700;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --shadow-sm: 0 1px 2px rgba(16, 24, 40, .06);
  --shadow-md: 0 10px 28px rgba(16, 24, 40, .09);
  --space-1: .25rem;
  --space-2: .5rem;
  --space-3: .75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;
  --content-width: 1280px;
  --reading-width: 820px;
  --header-height: 64px;
  --sidebar-width: 300px;
  --toc-width: 220px;
  --focus-ring: 0 0 0 3px rgba(8, 127, 91, .2);
  --font-sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "Cascadia Code", "SFMono-Regular", Consolas, monospace;
}

[data-theme="dark"] {
  color-scheme: dark;
  --tn-bg: #0c131d;
  --tn-surface: #111c29;
  --tn-surface-soft: #182536;
  --tn-text: #edf3f8;
  --tn-muted: #a8b5c4;
  --tn-border: #2a394b;
  --tn-accent: #55d6a9;
  --tn-accent-strong: #7be4bd;
  --tn-accent-soft: #14352d;
  --tn-navy: #a8ccff;
  --tn-code: #07101b;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, .2);
  --shadow-md: 0 14px 34px rgba(0, 0, 0, .28);
  --focus-ring: 0 0 0 3px rgba(85, 214, 169, .25);
}

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-height) + 1.5rem); }
body { margin: 0; color: var(--tn-text); background: var(--tn-bg); font-family: var(--font-sans); font-size: 16.5px; line-height: 1.7; }
body, button, input, select, textarea { font-family: var(--font-sans); }
* { box-sizing: border-box; }
img { max-width: 100%; height: auto; }
a { color: var(--tn-accent-strong); text-underline-offset: .18em; }
p { color: var(--tn-muted); }
h1, h2, h3, h4 { color: var(--tn-text); line-height: 1.18; letter-spacing: -.025em; }
h1 { font-size: clamp(2.35rem, 5vw, 2.75rem); }
h2 { font-size: clamp(1.75rem, 3.5vw, 2rem); }
h3 { font-size: clamp(1.25rem, 2.2vw, 1.5rem); }
.container { width: min(calc(100% - 2rem), var(--content-width)); margin-inline: auto; }
.nova-section { padding-block: clamp(3.5rem, 7vw, 6rem); }
.section-alt { background: var(--tn-surface-soft) !important; }
.section-heading { max-width: 720px; }
.section-heading p { max-width: 65ch; }
.section-tag, .reader-eyebrow { color: var(--tn-accent-strong) !important; font-size: .78rem; font-weight: 750; letter-spacing: .09em; text-transform: uppercase; }

.topbar { position: sticky !important; top: 0; z-index: 1000; min-height: var(--header-height); border-bottom: 1px solid var(--tn-border) !important; background: color-mix(in srgb, var(--tn-surface) 94%, transparent) !important; box-shadow: none !important; backdrop-filter: blur(12px); }
.page-loader { display: none !important; }
.nav-container { min-height: var(--header-height) !important; display: flex; align-items: center; gap: 1.25rem; }
.brand { color: var(--tn-text) !important; font-size: 1.3rem !important; font-weight: 800; letter-spacing: -.035em; text-decoration: none; }
.brand::before { content: ""; display: inline-block; width: .7rem; height: .7rem; margin-right: .45rem; border-radius: 3px; background: var(--tn-accent); transform: rotate(45deg); }
.site-nav { display: flex; align-items: center; justify-content: flex-end; gap: .15rem; margin-left: auto; }
.site-nav > a, .site-nav > div > a { padding: .48rem .52rem !important; border-radius: var(--radius-sm); color: var(--tn-muted) !important; font-size: .86rem; font-weight: 650; text-decoration: none; }
.site-nav a:hover, .site-nav a.active { color: var(--tn-text) !important; background: var(--tn-surface-soft); }
.site-nav .nav-register { margin-left: .35rem; color: #fff !important; background: var(--tn-accent) !important; }
.site-nav .nav-register:hover { background: var(--tn-accent-strong) !important; }
.has-mega-menu { position: relative; }
.mega-menu { position: absolute !important; top: calc(100% + .35rem); left: 0; z-index: 20; display: none !important; min-width: 230px; padding: .4rem; border: 1px solid var(--tn-border) !important; border-radius: var(--radius-md) !important; background: var(--tn-surface) !important; box-shadow: var(--shadow-md) !important; }
.has-mega-menu:hover > .mega-menu, .has-mega-menu:focus-within > .mega-menu { display: grid !important; }
.mega-menu a { color: var(--tn-muted) !important; }
.tn-nav-tools { display: flex; align-items: center; gap: .35rem; margin-left: .35rem; }
.tn-icon-button { display: grid; width: 38px; height: 38px; padding: 0; place-items: center; border: 1px solid var(--tn-border); border-radius: var(--radius-sm); color: var(--tn-muted); background: var(--tn-surface); cursor: pointer; }
.tn-icon-button:hover { color: var(--tn-text); border-color: var(--tn-accent); }
.tn-icon-button svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 2; }
.nav-toggle { display: none; width: 40px; height: 40px; padding: 0; place-items: center; border: 1px solid var(--tn-border); border-radius: var(--radius-sm); background: var(--tn-surface); cursor: pointer; }
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after { display: block; width: 18px; height: 2px; border-radius: 2px; background: var(--tn-text); content: ""; }
.nav-toggle span::before { transform: translateY(-6px); }
.nav-toggle span::after { transform: translateY(4px); }

.primary-btn, .secondary-btn, button.primary-btn, button.secondary-btn { min-height: 42px; padding: .62rem 1rem !important; border-radius: var(--radius-md) !important; font-weight: 700; box-shadow: none !important; transform: none !important; }
.primary-btn { border: 1px solid var(--tn-accent) !important; color: #fff !important; background: var(--tn-accent) !important; }
.primary-btn:hover { border-color: var(--tn-accent-strong) !important; background: var(--tn-accent-strong) !important; }
.secondary-btn { border: 1px solid var(--tn-border) !important; color: var(--tn-text) !important; background: var(--tn-surface) !important; }
.secondary-btn:hover { border-color: var(--tn-accent) !important; color: var(--tn-accent-strong) !important; }
.glass-card, .feature-card, .outcome-card, .course-card, .course-discovery-card { border: 1px solid var(--tn-border) !important; border-radius: var(--radius-lg) !important; color: var(--tn-text); background: var(--tn-surface) !important; box-shadow: var(--shadow-sm) !important; }
.glass-card:hover, .feature-card:hover, .course-discovery-card:hover { border-color: color-mix(in srgb, var(--tn-accent) 42%, var(--tn-border)) !important; transform: translateY(-2px); }
.nova-hero, .page-hero-section { color: var(--tn-text) !important; background: var(--tn-surface) !important; }
.landing-hero { min-height: auto !important; padding-block: clamp(5rem, 10vw, 8rem) !important; }
.landing-hero__content { max-width: 850px !important; margin-inline: auto; text-align: center; }
.landing-hero h1 { max-width: 17ch; margin-inline: auto; }
.hero-subtitle { max-width: 58ch; margin-inline: auto; font-size: clamp(1.08rem, 2vw, 1.25rem); }
.hero-actions { justify-content: center; }

input, select, textarea { min-height: 44px; border: 1px solid var(--tn-border) !important; border-radius: var(--radius-md) !important; color: var(--tn-text) !important; background: var(--tn-surface) !important; }
input:focus, select:focus, textarea:focus { border-color: var(--tn-accent) !important; outline: 0; box-shadow: var(--focus-ring) !important; }
label { color: var(--tn-text); font-weight: 650; }
.modal { color: var(--tn-text); }
.modal-overlay { background: rgba(8, 15, 25, .66) !important; backdrop-filter: blur(3px); }
.modal-container { width: min(94vw, 600px) !important; max-height: 90vh; overflow-y: auto; border: 1px solid var(--tn-border) !important; border-radius: var(--radius-lg) !important; background: var(--tn-surface) !important; box-shadow: var(--shadow-md) !important; }
.modal-header { border-bottom: 1px solid var(--tn-border); }
.modal-close { border-radius: var(--radius-sm) !important; }

.site-footer { padding-top: 3.5rem !important; border-top: 1px solid var(--tn-border) !important; color: var(--tn-muted) !important; background: #0e1a28 !important; }
.site-footer h3, .site-footer .brand { color: #f5f8fb !important; }
.site-footer a, .site-footer p { color: #aebdca !important; }
.site-footer a:hover { color: #fff !important; }

table { border-collapse: collapse; background: var(--tn-surface); }
th { color: var(--tn-text); background: var(--tn-surface-soft); }
th, td { padding: .8rem .9rem; border: 1px solid var(--tn-border); text-align: left; }
tbody tr:hover { background: color-mix(in srgb, var(--tn-accent-soft) 45%, transparent); }
pre { max-width: 100%; overflow-x: auto; border: 1px solid #25344a; border-radius: var(--radius-md) !important; background: var(--tn-code) !important; }
code { font-family: var(--font-mono); }
:focus-visible { outline: 2px solid var(--tn-accent) !important; outline-offset: 3px !important; }

.tn-search-dialog { position: fixed; inset: 0; z-index: 2500; display: none; padding: max(8vh, 2rem) 1rem; background: rgba(7, 13, 22, .68); backdrop-filter: blur(5px); }
.tn-search-dialog.is-open { display: block; }
.tn-search-panel { width: min(680px, 100%); max-height: 78vh; margin: 0 auto; overflow: hidden; border: 1px solid var(--tn-border); border-radius: var(--radius-lg); background: var(--tn-surface); box-shadow: var(--shadow-md); }
.tn-search-head { display: flex; align-items: center; gap: .75rem; padding: .85rem; border-bottom: 1px solid var(--tn-border); }
.tn-search-head input { flex: 1; border: 0 !important; box-shadow: none !important; font-size: 1rem; }
.tn-search-results { max-height: 60vh; padding: .55rem; overflow-y: auto; }
.tn-search-group h3 { margin: .8rem .65rem .35rem; color: var(--tn-muted); font-size: .75rem; letter-spacing: .08em; text-transform: uppercase; }
.tn-search-result { display: block; padding: .7rem .75rem; border-radius: var(--radius-sm); color: var(--tn-text); text-decoration: none; }
.tn-search-result:hover, .tn-search-result:focus { background: var(--tn-accent-soft); }
.tn-search-result small { display: block; color: var(--tn-muted); }
.tn-search-empty { padding: 2rem 1rem; text-align: center; }

.tn-reader-toc { position: sticky; top: calc(var(--header-height) + 1.25rem); width: var(--toc-width); max-height: calc(100vh - var(--header-height) - 2rem); padding-left: 1.1rem; overflow-y: auto; border-left: 1px solid var(--tn-border); }
.tn-reader-toc h2 { margin: 0 0 .75rem; font-size: .78rem; letter-spacing: .08em; text-transform: uppercase; }
.tn-reader-toc a { display: block; padding: .35rem 0 .35rem .65rem; border-left: 2px solid transparent; color: var(--tn-muted); font-size: .82rem; line-height: 1.35; text-decoration: none; }
.tn-reader-toc a.is-active { border-left-color: var(--tn-accent); color: var(--tn-accent-strong); font-weight: 700; }
.learning-reader-modern {
  --reader-bg: var(--tn-bg) !important;
  --reader-surface: var(--tn-surface) !important;
  --reader-surface-soft: var(--tn-surface-soft) !important;
  --reader-border: var(--tn-border) !important;
  --reader-text: var(--tn-text) !important;
  --reader-muted: var(--tn-muted) !important;
  --reader-subtle: color-mix(in srgb, var(--tn-muted) 78%, transparent) !important;
  --reader-accent: var(--tn-accent) !important;
  --reader-accent-strong: var(--tn-accent-strong) !important;
  --reader-success: #22a06b !important;
  --reader-warning: #d99a00 !important;
  --reader-danger: var(--tn-danger) !important;
  background: var(--tn-bg) !important;
}
body[data-ai-reader-track="playwright"] {
  --tn-accent: #0f9d72;
  --tn-accent-strong: #08795a;
  --tn-accent-soft: #e6f7f1;
}
body[data-ai-reader-track="jsTs"] {
  --tn-accent: #2563eb;
  --tn-accent-strong: #1d4ed8;
  --tn-accent-soft: #eaf1ff;
}
[data-theme="dark"] body[data-ai-reader-track="playwright"] { --tn-accent-soft: #12382e; }
[data-theme="dark"] body[data-ai-reader-track="jsTs"] { --tn-accent-soft: #172c57; }
.learning-reader-modern .ai-reader-topic-nav button[data-topic-link] > span { color: #fff !important; background: linear-gradient(135deg, var(--tn-accent), #7c3aed) !important; }
.learning-reader-modern .ai-reader-topic-nav button[data-topic-link].active { border-color: color-mix(in srgb, var(--tn-accent) 45%, var(--tn-border)) !important; box-shadow: inset 3px 0 0 var(--tn-accent); }
.learning-reader-modern .ai-reader-sidebar { scrollbar-color: var(--tn-border) transparent !important; }
.learning-reader-modern .ai-reader-toolbar { color: var(--tn-muted) !important; background: var(--tn-bg) !important; }
.learning-reader-modern .ai-reader-topic-link { color: var(--tn-muted) !important; }
.learning-reader-modern .ai-reader-topic-link:hover { color: var(--tn-text) !important; background: var(--tn-surface-soft) !important; }
.learning-reader-modern .ai-reader-topic-link.active { color: var(--tn-text) !important; background: var(--tn-accent-soft) !important; }
.learning-reader-modern .reader-nav-group > summary { color: var(--tn-muted) !important; }
.learning-reader-modern .ai-ui-flow span { border-color: var(--tn-border) !important; color: var(--tn-text) !important; background: var(--tn-surface-soft) !important; }
.learning-reader-modern .reader-answer summary { border-color: var(--tn-border) !important; color: var(--tn-text) !important; }
.learning-reader-modern .ai-reader-shell { grid-template-columns: var(--sidebar-width) minmax(0, var(--reading-width)) var(--toc-width) !important; max-width: 1440px !important; align-items: start; }
.learning-reader-modern .ai-reader-main { min-width: 0; }
.learning-reader-modern .ai-reader-content { width: 100%; max-width: var(--reading-width); }
.learning-reader-modern .ai-reader-content, .learning-reader-modern .ai-reader-content * { min-width: 0; }
.learning-reader-modern .ai-reader-content h1, .learning-reader-modern .ai-reader-content h2, .learning-reader-modern .ai-reader-content h3, .learning-reader-modern .ai-reader-content p { max-width: 100%; overflow-wrap: anywhere; }
.learning-reader-modern .reader-learning-objective { border-left-color: var(--tn-accent) !important; background: var(--tn-accent-soft) !important; }
.learning-reader-modern .reader-learning-callout { border-radius: var(--radius-md) !important; }
.learning-reader-modern .ai-code-example { border-radius: var(--radius-md) !important; }
.learning-reader-modern .ai-inline-save-panel, .learning-reader-modern [contenteditable="true"] + .ai-inline-save-panel { display: none !important; }
body:not(.is-admin-mode) [contenteditable="true"] { pointer-events: auto; }
body:not(.is-admin-mode) .editable-surface, body:not(.is-admin-mode) [data-topic-edit] { caret-color: transparent; }

@media (max-width: 1199px) {
  .tn-reader-toc { display: none; }
  .learning-reader-modern .ai-reader-shell { display: block !important; max-width: 900px !important; }
}
@media (max-width: 980px) {
  .site-nav { position: fixed; inset: var(--header-height) 0 auto 0; display: none !important; max-height: calc(100vh - var(--header-height)); padding: .75rem 1rem 1rem; overflow-y: auto; border-bottom: 1px solid var(--tn-border); background: var(--tn-surface); box-shadow: var(--shadow-md); }
  .site-nav.open { display: grid !important; }
  .site-nav > a, .site-nav > div > a { display: block; padding: .75rem !important; }
  .site-nav .mega-menu { position: static !important; display: grid !important; margin: .25rem 0 .5rem; box-shadow: none !important; }
  .nav-toggle { display: grid; margin-left: auto; }
  .tn-nav-tools { margin-left: 0; }
}
@media (max-width: 640px) {
  :root { --header-height: 58px; }
  body { font-size: 16px; }
  .container { width: min(calc(100% - 2rem), var(--content-width)); }
  .nova-section { padding-block: 3.25rem; }
  .landing-hero { padding-block: 4.25rem !important; }
  .hero-actions { align-items: stretch; }
  .hero-actions .primary-btn, .hero-actions .secondary-btn { width: 100%; }
  .tn-search-trigger .tn-search-label { display: none; }
  .tn-search-dialog { padding: 0; }
  .tn-search-panel { min-height: 100dvh; border: 0; border-radius: 0; }
  .modal-overlay { align-items: flex-end !important; padding: 0 !important; }
  .modal-container { width: 100% !important; max-height: 92dvh; border-radius: var(--radius-lg) var(--radius-lg) 0 0 !important; }
  .learning-reader-modern .ai-reader-shell { width: min(100% - 1.5rem, 900px) !important; }
  .learning-reader-modern .ai-reader-main { width: 100%; overflow: hidden; }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; transition-duration: .01ms !important; } }