/* ═══════════════════════════════════════════════════════════════
   TangentFlow Design System
   Inspired by bibinmathew.com — warm, minimal, editorial
   ═══════════════════════════════════════════════════════════════ */

/* ── Tokens ─────────────────────────────────────────────────── */
:root {
  /* Colors */
  --color-bg: #faf9f6;
  --color-bg-alt: #f2f0ec;
  --color-surface: #ffffff;
  --color-text: #1a1815;
  --color-text-secondary: #6b6560;
  --color-text-muted: #9b9590;
  --color-border: #e8e4df;
  --color-border-light: #f0ece7;

  /* Sage accent */
  --color-accent: #5c7a64;
  --color-accent-light: #7d9885;
  --color-accent-dark: #4a6250;
  --color-accent-bg: #5c7a640a;
  --color-accent-bg-hover: #5c7a6412;

  /* Semantic */
  --color-success: #3d8b4f;
  --color-error: #c4473a;

  /* Typography */
  --font-body: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-heading: 'Newsreader', Georgia, 'Times New Roman', serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 40px;
  --space-2xl: 64px;
  --space-3xl: 96px;
  --space-section: clamp(64px, 10vw, 120px);

  /* Layout */
  --max-width: 960px;
  --max-width-narrow: 680px;
  --max-width-wide: 1200px;
  --nav-height: 64px;

  /* Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-pill: 9999px;

  /* Transitions */
  --ease: cubic-bezier(.4, 0, .2, 1);
  --duration-fast: 150ms;
  --duration: 300ms;
}

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

html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }

/* ── Typography ─────────────────────────────────────────────── */
.heading-xl {
  font-family: var(--font-heading);
  font-size: clamp(2.5rem, 5vw, 3.5rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  font-weight: 400;
  color: var(--color-text);
}

.heading-lg {
  font-family: var(--font-heading);
  font-size: clamp(1.8rem, 3vw, 2.5rem);
  line-height: 1.15;
  letter-spacing: -0.015em;
  font-weight: 400;
}

.heading-md {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  line-height: 1.25;
  letter-spacing: -0.01em;
  font-weight: 400;
}

.heading-sm {
  font-family: var(--font-body);
  font-size: 1.125rem;
  line-height: 1.35;
  font-weight: 600;
}

.body-lg {
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
}

.body-sm {
  font-size: 0.875rem;
  line-height: 1.5;
}

.caption {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  line-height: 1.4;
}

.text-muted { color: var(--color-text-secondary); }
.text-accent { color: var(--color-accent); }
.text-center { text-align: center; }
.font-serif { font-family: var(--font-heading); }
.font-mono { font-family: var(--font-mono); }

/* ── Layout ─────────────────────────────────────────────────── */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.container-narrow {
  max-width: var(--max-width-narrow);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.container-wide {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.section { padding: var(--space-section) 0; }
.section + .section { padding-top: 0; }

.section-border {
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-section);
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-xl);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.flex-col { display: flex; flex-direction: column; }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }
.gap-xl { gap: var(--space-xl); }

/* ── Buttons ────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border-radius: var(--radius-pill);
  padding: 11px 28px;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  font-weight: 500;
  line-height: 1.2;
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease);
  border: 1.5px solid transparent;
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--color-accent);
  color: #fff;
  border-color: var(--color-accent);
}

.btn-primary:hover {
  background: var(--color-accent-dark);
  border-color: var(--color-accent-dark);
}

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

.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-secondary);
  border: none;
  padding: 8px 4px;
}

.btn-ghost:hover { color: var(--color-accent); }

.btn-lg {
  padding: 14px 36px;
  font-size: 1rem;
}

.btn-sm {
  padding: 7px 18px;
  font-size: 0.8125rem;
}

/* ── Badge ──────────────────────────────────────────────────── */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--color-accent-bg);
  color: var(--color-accent);
  border: 1px solid var(--color-accent-bg-hover);
  border-radius: var(--radius-pill);
  padding: 6px 16px;
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.01em;
}

/* ── Cards ──────────────────────────────────────────────────── */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  padding: var(--space-xl);
  transition: box-shadow var(--duration) var(--ease);
}

.card:hover {
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.05);
}

.card-accent {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 1px var(--color-accent);
}

/* ── Navigation ─────────────────────────────────────────────── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  background: rgba(250, 249, 246, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border-light);
}

.site-nav .nav-inner {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-nav .nav-logo {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.02em;
  text-decoration: none;
}

.site-nav .nav-logo span {
  color: var(--color-accent);
}

.site-nav .nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  list-style: none;
}

.site-nav .nav-links a {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  transition: color var(--duration-fast) var(--ease);
  text-decoration: none;
  font-weight: 450;
}

.site-nav .nav-links a:hover,
.site-nav .nav-links a.active {
  color: var(--color-accent);
}

.site-nav .nav-cta {
  margin-left: var(--space-sm);
}

.site-nav .nav-links .nav-cta a {
  color: #fff;
}

.site-nav .nav-links .nav-cta a:hover {
  color: #fff;
}

.nav-hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  color: var(--color-text);
}

.nav-hamburger svg { width: 24px; height: 24px; }

/* ── Footer ─────────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--color-border-light);
  padding: var(--space-xl) 0;
  background: var(--color-bg);
}

.site-footer .footer-inner {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-footer .footer-text {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

.site-footer .footer-links {
  display: flex;
  gap: var(--space-md);
  list-style: none;
}

.site-footer .footer-links a {
  color: var(--color-text-muted);
  transition: color var(--duration-fast) var(--ease);
}

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

/* ── Hero ───────────────────────────────────────────────────── */
.hero {
  padding: var(--space-3xl) 0 var(--space-2xl);
  text-align: center;
}

.hero .heading-xl {
  max-width: 720px;
  margin: 0 auto;
}

.hero .body-lg {
  max-width: 560px;
  margin: var(--space-lg) auto 0;
}

.hero .hero-actions {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  margin-top: var(--space-xl);
}

.hero .badge { margin-bottom: var(--space-lg); }

/* ── Feature Cards ──────────────────────────────────────────── */
.feature-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: var(--color-accent-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-md);
  color: var(--color-accent);
  font-size: 1.25rem;
}

.feature-card h3 {
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: var(--space-sm);
}

.feature-card p {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ── Comparison Table ───────────────────────────────────────── */
.comparison-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9375rem;
}

.comparison-table th,
.comparison-table td {
  padding: 14px 16px;
  text-align: left;
  border-bottom: 1px solid var(--color-border-light);
}

.comparison-table th {
  font-weight: 600;
  font-size: 0.8125rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-muted);
  background: var(--color-bg-alt);
}

.comparison-table th:first-child { border-radius: var(--radius-sm) 0 0 0; }
.comparison-table th:last-child { border-radius: 0 var(--radius-sm) 0 0; }

.comparison-table td:first-child { font-weight: 500; }

.comparison-table .highlight-col {
  background: var(--color-accent-bg);
  font-weight: 600;
}

.comparison-table .check { color: var(--color-success); font-weight: 700; }
.comparison-table .cross { color: var(--color-error); }
.comparison-table .partial { color: var(--color-text-muted); }

/* ── Steps ──────────────────────────────────────────────────── */
.step {
  display: flex;
  align-items: flex-start;
  gap: var(--space-lg);
}

.step-number {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--color-accent);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
  flex-shrink: 0;
}

.step-content h3 {
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.step-content p {
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
}

/* ── Testimonials ───────────────────────────────────────────── */
.testimonial {
  padding: var(--space-xl);
}

.testimonial blockquote {
  font-family: var(--font-heading);
  font-size: 1.125rem;
  font-style: italic;
  line-height: 1.6;
  color: var(--color-text);
  margin-bottom: var(--space-md);
}

.testimonial blockquote::before { content: '\201C'; }
.testimonial blockquote::after { content: '\201D'; }

.testimonial .testimonial-author {
  font-size: 0.875rem;
  font-weight: 500;
}

.testimonial .testimonial-role {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

/* ── Pricing Cards ──────────────────────────────────────────── */
.pricing-card { text-align: center; }

.pricing-card .pricing-name {
  font-weight: 600;
  font-size: 1.125rem;
  margin-bottom: var(--space-sm);
}

.pricing-card .pricing-price {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-xs);
}

.pricing-card .pricing-period {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-bottom: var(--space-lg);
}

.pricing-card .pricing-features {
  list-style: none;
  text-align: left;
  margin-bottom: var(--space-xl);
}

.pricing-card .pricing-features li {
  padding: 8px 0;
  border-bottom: 1px solid var(--color-border-light);
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.pricing-card .pricing-features li::before {
  content: '\2713';
  color: var(--color-accent);
  font-weight: 700;
  font-size: 0.875rem;
}

/* ── FAQ ────────────────────────────────────────────────────── */
.faq-item {
  border-bottom: 1px solid var(--color-border-light);
  padding: var(--space-lg) 0;
}

.faq-item h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: var(--space-sm);
}

.faq-item p {
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
  line-height: 1.7;
}

/* ── Docs ──────────────────────────────────────────────────── */
.docs-layout {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: var(--space-2xl);
  align-items: start;
}

.docs-sidebar {
  position: sticky;
  top: calc(var(--nav-height) + var(--space-lg));
  max-height: calc(100vh - var(--nav-height) - var(--space-2xl));
  overflow-y: auto;
}

.docs-sidebar ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.docs-sidebar a {
  display: block;
  padding: 6px 12px;
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  transition: all var(--duration-fast) var(--ease);
  text-decoration: none;
}

.docs-sidebar a:hover {
  color: var(--color-accent);
  background: var(--color-accent-bg);
}

.docs-sidebar a.active {
  color: var(--color-accent);
  background: var(--color-accent-bg);
  font-weight: 500;
}

.docs-sidebar .sidebar-section {
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
  padding: 16px 12px 4px;
  font-weight: 600;
}

.docs-sidebar .sidebar-section:first-child { padding-top: 0; }

.docs-content {
  min-width: 0;
}

.docs-content .prose { max-width: 100%; }

@media (max-width: 768px) {
  .docs-layout {
    grid-template-columns: 1fr;
  }
  .docs-sidebar {
    position: static;
    border-bottom: 1px solid var(--color-border-light);
    padding-bottom: var(--space-lg);
    margin-bottom: var(--space-lg);
  }
  .docs-sidebar ul { flex-direction: row; flex-wrap: wrap; gap: 4px; }
  .docs-sidebar a { padding: 4px 10px; font-size: 0.8125rem; }
  .docs-sidebar .sidebar-section { display: none; }
}

/* ── Blog ───────────────────────────────────────────────────── */
.post-card {
  padding: var(--space-xl) 0;
  border-bottom: 1px solid var(--color-border-light);
  transition: padding-left var(--duration) var(--ease);
}

.post-card:first-child { padding-top: 0; }

.post-card:hover { padding-left: var(--space-md); }

.post-card time {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

.post-card h2 {
  font-family: var(--font-heading);
  font-size: 1.375rem;
  font-weight: 400;
  margin: var(--space-sm) 0;
  line-height: 1.3;
}

.post-card h2 a {
  text-decoration: none;
  color: var(--color-text);
  transition: color var(--duration-fast) var(--ease);
}

.post-card h2 a:hover { color: var(--color-accent); }

.post-card p {
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
  line-height: 1.6;
}

.post-card .read-more {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-top: var(--space-sm);
  font-size: 0.875rem;
  color: var(--color-accent);
  font-weight: 500;
  transition: gap var(--duration-fast) var(--ease);
}

.post-card:hover .read-more { gap: 8px; }

/* ── Breadcrumb ─────────────────────────────────────────────── */
.breadcrumb {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin-bottom: var(--space-xl);
}

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

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

/* ── Prose (blog content) ───────────────────────────────────── */
.prose { max-width: var(--max-width-narrow); }

.prose h2 {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  margin-top: var(--space-2xl);
  margin-bottom: var(--space-md);
  letter-spacing: -0.01em;
}

.prose h3 {
  font-family: var(--font-body);
  font-size: 1.125rem;
  font-weight: 600;
  margin-top: var(--space-xl);
  margin-bottom: var(--space-sm);
}

.prose p {
  margin-bottom: var(--space-md);
  line-height: 1.75;
  color: var(--color-text-secondary);
}

.prose ul, .prose ol {
  margin-bottom: var(--space-md);
  padding-left: var(--space-lg);
  color: var(--color-text-secondary);
}

.prose li { margin-bottom: var(--space-sm); line-height: 1.7; }

.prose strong { color: var(--color-text); font-weight: 600; }

.prose a {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.prose a:hover { text-decoration-color: var(--color-accent-light); }

.prose code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-bg-alt);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--color-text);
}

.prose pre {
  background: #1a1815;
  color: #e8e4dc;
  padding: var(--space-lg);
  border-radius: var(--radius-sm);
  overflow-x: auto;
  margin-bottom: var(--space-lg);
  font-size: 0.875rem;
  line-height: 1.6;
}

.prose pre code {
  background: none;
  padding: 0;
  color: inherit;
}

.prose blockquote {
  border-left: 3px solid var(--color-accent);
  padding-left: var(--space-lg);
  margin: var(--space-lg) 0;
  font-style: italic;
  color: var(--color-text-secondary);
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: var(--space-lg);
  font-size: 0.9375rem;
}

.prose table th,
.prose table td {
  padding: 10px 14px;
  border: 1px solid var(--color-border);
  text-align: left;
}

.prose table th {
  background: var(--color-bg-alt);
  font-weight: 600;
  font-size: 0.8125rem;
}

.prose img {
  border-radius: var(--radius-sm);
  margin: var(--space-lg) 0;
}

/* ── Post Footer ────────────────────────────────────────────── */
.post-footer {
  margin-top: var(--space-2xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border-light);
}

.post-footer a {
  color: var(--color-accent);
  font-size: 0.9375rem;
  font-weight: 500;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: gap var(--duration-fast) var(--ease);
}

.post-footer a:hover { gap: 10px; }

/* ── CTA Section ────────────────────────────────────────────── */
.cta-section {
  text-align: center;
  padding: var(--space-3xl) 0;
}

.cta-section .heading-lg {
  margin-bottom: var(--space-md);
}

.cta-section .body-lg {
  max-width: 480px;
  margin: 0 auto var(--space-xl);
}

/* ── App Page ───────────────────────────────────────────────── */
.page-app { background: #0e1117; }

.app-workspace {
  min-height: calc(100vh - var(--nav-height));
}

/* ── Responsive ─────────────────────────────────────────────── */
@media (max-width: 768px) {
  .grid-2 { grid-template-columns: 1fr; }
  .grid-3 { grid-template-columns: 1fr; }

  .hero { padding: var(--space-2xl) 0 var(--space-xl); }
  .hero .hero-actions { flex-direction: column; align-items: center; }

  .nav-links { display: none !important; }
  .nav-hamburger { display: block; }

  .nav-links.open {
    display: flex !important;
    flex-direction: column;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-lg);
    gap: var(--space-md);
  }

  .site-footer .footer-inner {
    flex-direction: column;
    gap: var(--space-md);
    text-align: center;
  }

  .comparison-table { font-size: 0.8125rem; }
  .comparison-table th,
  .comparison-table td { padding: 10px 8px; }
}

@media (max-width: 480px) {
  .heading-xl { font-size: 2rem; }
  .container { padding: 0 var(--space-md); }
}