/* ==========================================================================
   Claude Skill Hub – Design system & layout
   ========================================================================== */

:root {
  /* Typography */
  --font-heading: 'Syne', system-ui, sans-serif;
  --font-body: 'Source Sans 3', system-ui, sans-serif;

  /* Spacing (8px base) */
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 48px;
  --space-6: 64px;

  /* Colors – dark theme, warm accent */
  --bg-primary: #0d0d0f;
  --bg-secondary: #141416;
  --bg-card: #1a1a1d;
  --bg-elevated: #222226;
  --text-primary: #f2f2f4;
  --text-secondary: #a0a0a8;
  --text-muted: #6b6b72;
  --accent: #e8a54b;
  --accent-hover: #f0b85c;
  --accent-muted: rgba(232, 165, 75, 0.15);
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.12);

  /* Shadows & effects */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.5);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --transition: 0.2s ease;

  /* Layout */
  --container-max: 1120px;
  --header-height: 72px;
}

/* Reset & base */
*, *::before, *::after { box-sizing: border-box; }
html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}
body {
  margin: 0;
  font-family: var(--font-body);
  font-size: clamp(16px, 2vw, 18px);
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-primary);
  min-height: 100vh;
}
img {
  max-width: 100%;
  height: auto;
  display: block;
}
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }
a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

/* Skip link (A11y) */
.skip-link {
  position: absolute;
  top: -100px;
  left: var(--space-2);
  padding: var(--space-1) var(--space-2);
  background: var(--accent);
  color: var(--bg-primary);
  font-weight: 600;
  z-index: 1000;
  border-radius: var(--radius-sm);
  transition: top var(--transition);
}
.skip-link:focus {
  top: var(--space-2);
  outline: none;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  margin: 0 0 var(--space-2);
}
h1 { font-size: clamp(28px, 5vw, 56px); }
h2 { font-size: clamp(22px, 3.5vw, 36px); margin-bottom: var(--space-3); }
h3 { font-size: clamp(18px, 2.5vw, 22px); margin-bottom: var(--space-1); }
p { margin: 0 0 var(--space-2); color: var(--text-secondary); }
p:last-child { margin-bottom: 0; }

/* Breadcrumb */
.breadcrumb {
  position: absolute;
  top: var(--header-height);
  left: 0;
  right: 0;
  padding: var(--space-1) var(--space-3);
  font-size: 0.875rem;
  background: transparent;
  z-index: 1;
}
.breadcrumb ol {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
}
.breadcrumb a {
  color: var(--text-muted);
}
.breadcrumb a:hover { color: var(--accent); }

/* Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-3);
}
@media (min-width: 768px) {
  .container { padding: 0 var(--space-4); }
}

/* ==========================================================================
   Header
   ========================================================================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(13, 13, 15, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: background var(--transition), border-color var(--transition);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-3);
}
.logo {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--text-primary);
}
.logo:hover { color: var(--text-primary); }
.logo-mark { color: var(--accent); }
.nav-main { display: none; }
@media (min-width: 900px) {
  .nav-main { display: block; }
  .nav-list {
    display: flex;
    gap: var(--space-4);
    list-style: none;
    margin: 0;
    padding: 0;
  }
  .nav-list a {
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.9375rem;
  }
  .nav-list a:hover { color: var(--text-primary); }
}
.header-actions {
  display: none;
  gap: var(--space-2);
}
@media (min-width: 900px) {
  .header-actions { display: flex; }
}
.menu-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-primary);
  border-radius: var(--radius-sm);
  transition: background var(--transition);
}
.menu-toggle:hover { background: var(--bg-elevated); }
.menu-toggle:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.menu-toggle[aria-expanded="true"] .menu-bar:nth-child(1) { transform: translateY(8px) rotate(45deg); }
.menu-toggle[aria-expanded="true"] .menu-bar:nth-child(2) { opacity: 0; }
.menu-toggle[aria-expanded="true"] .menu-bar:nth-child(3) { transform: translateY(-8px) rotate(-45deg); }
.menu-bar {
  display: block;
  width: 22px;
  height: 2px;
  background: currentColor;
  border-radius: 1px;
  transition: transform var(--transition), opacity var(--transition);
}
@media (min-width: 900px) {
  .menu-toggle { display: none; }
}
.nav-mobile {
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--bg-secondary);
  padding: var(--space-4);
  overflow-y: auto;
  transform: translateX(100%);
  opacity: 0;
  visibility: hidden;
  transition: transform 0.25s ease, opacity 0.25s ease, visibility 0.25s;
  z-index: 99;
}
.nav-mobile.open {
  transform: translateX(0);
  opacity: 1;
  visibility: visible;
}
.nav-mobile[aria-hidden="false"] {
  transform: translateX(0);
  opacity: 1;
  visibility: visible;
}
.nav-mobile-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.nav-mobile-list a {
  display: block;
  padding: var(--space-2);
  color: var(--text-primary);
  font-weight: 500;
  border-radius: var(--radius-sm);
}
.nav-mobile-list a:hover { background: var(--bg-elevated); color: var(--accent); }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-1) var(--space-3);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.9375rem;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: background var(--transition), color var(--transition), transform 0.15s ease;
}
.btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.btn-primary {
  background: var(--accent);
  color: var(--bg-primary);
}
.btn-primary:hover { background: var(--accent-hover); transform: translateY(-1px); }
.btn-secondary {
  background: var(--bg-elevated);
  color: var(--text-primary);
  border: 1px solid var(--border-strong);
}
.btn-secondary:hover { background: var(--bg-card); border-color: var(--text-muted); }
.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
}
.btn-ghost:hover { color: var(--text-primary); background: var(--bg-elevated); }
.btn-lg { padding: var(--space-2) var(--space-4); font-size: 1rem; }

/* ==========================================================================
   Hero
   ========================================================================== */
.hero {
  position: relative;
  min-height: 85vh;
  display: flex;
  align-items: center;
  padding: calc(var(--header-height) + var(--space-6)) var(--space-3) var(--space-6);
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, var(--accent-muted), transparent 50%),
    radial-gradient(ellipse 60% 40% at 80% 60%, rgba(80, 80, 90, 0.2), transparent 45%);
  pointer-events: none;
}
.hero-inner {
  position: relative;
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-2);
}
.hero h1 {
  max-width: 14ch;
  margin-bottom: var(--space-3);
  animation: fadeUp 0.7s ease both;
}
.hero-desc {
  max-width: 52ch;
  font-size: clamp(16px, 2vw, 18px);
  line-height: 1.65;
  margin-bottom: var(--space-4);
  animation: fadeUp 0.7s 0.1s ease both;
}
.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-5);
  animation: fadeUp 0.7s 0.2s ease both;
}
.hero-code {
  position: relative;
  display: inline-block;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--space-2) var(--space-4);
  padding-right: 52px;
  animation: fadeUp 0.7s 0.3s ease both;
}
.hero-code pre { margin: 0; }
.hero-code code {
  font-family: ui-monospace, monospace;
  font-size: clamp(14px, 1.5vw, 16px);
  color: var(--text-primary);
}
.copy-btn {
  position: absolute;
  top: 50%;
  right: var(--space-2);
  transform: translateY(-50%);
  padding: var(--space-1) var(--space-2);
  font-size: 0.8125rem;
  background: var(--bg-elevated);
  color: var(--text-secondary);
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
}
.copy-btn:hover { background: var(--accent-muted); color: var(--accent); }
.copy-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.copy-btn.copied { color: var(--accent); }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ==========================================================================
   Sections
   ========================================================================== */
.section {
  padding: var(--space-6) 0;
}
.section-desc {
  max-width: 56ch;
  margin-bottom: var(--space-5);
  font-size: clamp(16px, 1.8vw, 18px);
}
.section-cta { margin-top: var(--space-4); }
.link-arrow {
  color: var(--accent);
  font-weight: 600;
}
.link-arrow:hover { text-decoration: underline; }

/* Skills grid */
.skills-grid {
  display: grid;
  gap: var(--space-4);
  grid-template-columns: 1fr;
}
@media (min-width: 640px) {
  .skills-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 960px) {
  .skills-grid { grid-template-columns: repeat(3, 1fr); }
}
.skill-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  transition: border-color var(--transition), box-shadow var(--transition), transform 0.2s ease;
}
.skill-card:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}
.skill-badge {
  position: absolute;
  top: var(--space-3);
  right: var(--space-3);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
}
.skill-name {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  margin-bottom: var(--space-1);
}
.skill-desc {
  font-size: 0.9375rem;
  margin-bottom: var(--space-2);
  color: var(--text-secondary);
}
.skill-meta {
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-bottom: var(--space-2);
}
.skill-link {
  font-weight: 600;
  font-size: 0.9375rem;
}
.skill-link::after {
  content: ' →';
}

/* Compare table */
.table-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg-card);
}
.compare-table {
  width: 100%;
  min-width: 320px;
  border-collapse: collapse;
  font-size: clamp(14px, 1.5vw, 16px);
}
.compare-table th,
.compare-table td {
  padding: var(--space-2) var(--space-3);
  text-align: left;
  border-bottom: 1px solid var(--border);
}
.compare-table th {
  background: var(--bg-elevated);
  font-weight: 600;
  color: var(--text-primary);
}
.compare-table td { color: var(--text-secondary); }
.compare-table tbody tr:last-child td { border-bottom: none; }
.compare-table tbody tr:hover td { background: rgba(255,255,255,0.02); }

/* Features grid */
.features-grid {
  display: grid;
  gap: var(--space-4);
  grid-template-columns: 1fr;
}
@media (min-width: 640px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 960px) {
  .features-grid { grid-template-columns: repeat(4, 1fr); }
}
.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  transition: border-color var(--transition), transform 0.2s ease;
}
.feature-card:hover {
  border-color: var(--border-strong);
  transform: translateY(-2px);
}
.feature-icon {
  display: inline-block;
  font-size: 1.5rem;
  color: var(--accent);
  margin-bottom: var(--space-2);
}
.feature-card h3 { margin-bottom: var(--space-1); font-size: 1.125rem; }
.feature-card p { font-size: 0.9375rem; margin: 0; }

/* Use cases */
.use-cases-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--space-2);
  max-width: 56ch;
}
.use-cases-list li {
  padding: var(--space-2) var(--space-3);
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--accent);
  color: var(--text-secondary);
}

/* Tabs */
.tabs {
  display: flex;
  gap: var(--space-1);
  margin-bottom: var(--space-4);
  border-bottom: 1px solid var(--border);
}
.tab-btn {
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.9375rem;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  color: var(--text-muted);
  cursor: pointer;
  transition: color var(--transition), border-color var(--transition);
}
.tab-btn:hover { color: var(--text-secondary); }
.tab-btn.active,
.tab-btn[aria-selected="true"] {
  color: var(--accent);
  border-bottom-color: var(--accent);
}
.tab-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.tab-panel { display: block; }
.tab-panel.hidden { display: none; }
.guide-steps {
  margin: 0;
  padding-left: var(--space-4);
  color: var(--text-secondary);
}
.guide-steps li { margin-bottom: var(--space-3); }
.code-block {
  position: relative;
  display: inline-block;
  margin: var(--space-1) 0;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--space-2) var(--space-4);
  padding-right: 52px;
}
.code-block pre { margin: 0; }
.code-block code { font-family: ui-monospace, monospace; font-size: 0.9375rem; }
.code-block .copy-btn { top: 50%; right: var(--space-2); transform: translateY(-50%); }

/* Testimonials */
.testimonials-grid {
  display: grid;
  gap: var(--space-4);
  grid-template-columns: 1fr;
}
@media (min-width: 640px) {
  .testimonials-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 960px) {
  .testimonials-grid { grid-template-columns: repeat(3, 1fr); }
}
.testimonial-card {
  margin: 0;
  padding: var(--space-4);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  transition: border-color var(--transition), box-shadow var(--transition);
}
.testimonial-card:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-sm);
}
.testimonial-avatar {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  overflow: hidden;
  margin-bottom: var(--space-2);
  background: var(--bg-elevated);
}
.testimonial-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.testimonial-quote {
  font-size: 0.9375rem;
  font-style: italic;
  color: var(--text-secondary);
  margin-bottom: var(--space-2);
}
.testimonial-card footer {
  font-size: 0.875rem;
  color: var(--text-muted);
}
.testimonial-card cite { font-style: normal; font-weight: 600; color: var(--text-primary); }

/* Accordion (FAQ) */
.accordion { max-width: 720px; }
.accordion-item {
  border-bottom: 1px solid var(--border);
}
.accordion-item:first-child { border-top: 1px solid var(--border); }
.accordion-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) 0;
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 600;
  text-align: left;
  color: var(--text-primary);
  background: none;
  border: none;
  cursor: pointer;
  transition: color var(--transition);
}
.accordion-trigger:hover { color: var(--accent); }
.accordion-trigger:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.accordion-trigger::after {
  content: '';
  flex-shrink: 0;
  width: 12px;
  height: 12px;
  margin-left: var(--space-2);
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg);
  transition: transform var(--transition);
}
.accordion-trigger[aria-expanded="true"]::after { transform: rotate(-135deg); }
.accordion-panel {
  overflow: hidden;
  height: 0;
  transition: height 0.25s ease;
}
.accordion-panel[hidden] {
  display: block;
  height: 0;
}
.accordion-panel p {
  padding: 0 0 var(--space-3);
  margin: 0;
  font-size: 0.9375rem;
  color: var(--text-secondary);
}
.accordion-item h3 { margin: 0; }

/* CTA section */
.cta-section {
  text-align: center;
  padding: var(--space-6) 0;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
}
.cta-section h2 { margin-bottom: var(--space-2); }
.cta-section .section-desc { margin-left: auto; margin-right: auto; margin-bottom: var(--space-4); }
.cta-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  justify-content: center;
}

/* Footer */
.site-footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: var(--space-6) 0 0;
}
.footer-inner {
  display: grid;
  gap: var(--space-5);
  grid-template-columns: 1fr;
  padding-bottom: var(--space-5);
}
@media (min-width: 768px) {
  .footer-inner { grid-template-columns: 1.2fr 2fr; }
}
.footer-brand .logo {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--text-primary);
  margin-bottom: var(--space-2);
}
.footer-brand .logo:hover { color: var(--text-primary); }
.footer-brand p {
  font-size: 0.9375rem;
  color: var(--text-muted);
  max-width: 32ch;
  margin: 0;
}
.footer-nav {
  display: grid;
  gap: var(--space-4);
  grid-template-columns: repeat(2, 1fr);
}
@media (min-width: 640px) {
  .footer-nav { grid-template-columns: repeat(3, 1fr); }
}
.footer-col h4 {
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin: 0 0 var(--space-2);
}
.footer-col ul {
  list-style: none;
  margin: 0;
  padding: 0;
}
.footer-col li { margin-bottom: var(--space-1); }
.footer-col a {
  color: var(--text-secondary);
  font-size: 0.9375rem;
}
.footer-col a:hover { color: var(--accent); }
.footer-bottom {
  padding: var(--space-3) 0;
  border-top: 1px solid var(--border);
}
.footer-bottom .container {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
}
.copyright {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin: 0;
}
.footer-legal {
  display: flex;
  gap: var(--space-4);
  list-style: none;
  margin: 0;
  padding: 0;
}
.footer-legal a {
  font-size: 0.875rem;
  color: var(--text-muted);
}
.footer-legal a:hover { color: var(--text-secondary); }

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
  html { scroll-behavior: auto; }
}