/* SkillVerse — HP-inspired white commercial editorial style
   White canvas, blue accent, card-based index system, 16px rounded cards */

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

:root {
  --canvas:       #ffffff;
  --cloud:        #f7f7f7;
  --fog:          #e8e8e8;
  --card:         #ffffff;
  --ink:          #1a1a1a;
  --body:         #3d3d3d;
  --muted:        #636363;
  --hairline:     #e8e8e8;
  --hairline-str: #c2c2c2;
  --primary:      #024ad8;
  --primary-dark: #0e3191;
  --on-primary:   #ffffff;
  --badge-skill:  #c9e0fc;
  --badge-tool:   #dcedc8;
  --badge-role:   #fce4ec;
  --badge-cert:   #fff8e1;
  --shadow-soft:  0 2px 8px rgba(26,26,26,0.08);
  --shadow-float: 0 8px 24px rgba(26,26,26,0.12);
  --font: 'Inter', 'Manrope', system-ui, -apple-system, sans-serif;
  --radius-sm:  4px;
  --radius-md:  8px;
  --radius-lg: 16px;
  --radius-pill: 9999px;
  --space-xs:  8px;
  --space-sm:  12px;
  --space-md:  16px;
  --space-lg:  24px;
  --space-xl:  32px;
  --space-xxl: 48px;
  --space-section: 80px;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--canvas);
  color: var(--ink);
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }

.container {
  max-width: 1366px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--canvas);
  border-bottom: 1px solid var(--hairline);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

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

.logo-icon {
  font-size: 22px;
  color: var(--primary);
  line-height: 1;
}

.logo-text {
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.3px;
  color: var(--ink);
}

.logo-badge {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.7px;
  text-transform: uppercase;
  background: var(--badge-skill);
  color: var(--primary);
  padding: 2px 8px;
  border-radius: var(--radius-pill);
  margin-left: 4px;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 22px; height: 2px;
  background: var(--ink);
  border-radius: 2px;
}

.nav-list { display: flex; align-items: center; gap: 4px; }

.nav-link {
  display: block;
  padding: 6px 12px;
  font-size: 14px;
  font-weight: 500;
  color: var(--body);
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: color 0.15s, background 0.15s;
}

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

.nav-link.active { color: var(--primary); }

/* ===== Hero ===== */
.hero {
  padding: var(--space-section) 0;
  background: var(--cloud);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xxl);
  align-items: center;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.7px;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: var(--space-md);
}

.hero-title {
  font-size: clamp(32px, 5vw, 56px);
  font-weight: 500;
  line-height: 1.1;
  color: var(--ink);
  margin-bottom: var(--space-lg);
  letter-spacing: -0.5px;
}

.hero-desc {
  font-size: 18px;
  font-weight: 400;
  color: var(--body);
  line-height: 1.6;
  margin-bottom: var(--space-xl);
  max-width: 480px;
}

.hero-actions { display: flex; gap: var(--space-md); flex-wrap: wrap; }

.btn-primary {
  display: inline-flex;
  align-items: center;
  padding: 12px 24px;
  background: var(--primary);
  color: var(--on-primary);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.7px;
  text-transform: uppercase;
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: background 0.15s;
}

.btn-primary:hover { background: var(--primary-dark); text-decoration: none; }

.btn-outline {
  display: inline-flex;
  align-items: center;
  padding: 12px 24px;
  background: transparent;
  color: var(--ink);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.7px;
  text-transform: uppercase;
  border: 1px solid var(--ink);
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: background 0.15s;
}

.btn-outline:hover { background: var(--cloud); text-decoration: none; }

.hero-image {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-soft);
  border: 1px solid var(--hairline);
}

.hero-image img { width: 100%; height: 340px; object-fit: cover; }

/* ===== Section ===== */
.section {
  padding: var(--space-section) 0;
}

.section-alt { background: var(--cloud); }

.section-eyebrow {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.7px;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: var(--space-sm);
}

.section-title {
  font-size: clamp(26px, 3.5vw, 44px);
  font-weight: 500;
  letter-spacing: -0.3px;
  color: var(--ink);
  margin-bottom: var(--space-md);
  line-height: 1.15;
}

.section-lead {
  font-size: 16px;
  color: var(--body);
  max-width: 560px;
  margin-bottom: var(--space-xxl);
  line-height: 1.6;
}

/* ===== Cards Grid ===== */
.cards-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
}

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

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

.info-card {
  background: var(--card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
  padding: var(--space-lg);
  border: 1px solid var(--hairline);
  text-decoration: none;
  color: inherit;
  display: block;
  transition: box-shadow 0.15s;
}

.info-card:hover { box-shadow: var(--shadow-float); text-decoration: none; }

.card-icon {
  font-size: 32px;
  margin-bottom: var(--space-md);
  line-height: 1;
}

.card-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: var(--space-xs);
  line-height: 1.3;
}

.card-desc {
  font-size: 14px;
  color: var(--body);
  line-height: 1.5;
}

.card-tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  margin-bottom: var(--space-sm);
}

.tag-skill { background: var(--badge-skill); color: var(--primary); }
.tag-tool  { background: var(--badge-tool);  color: #2e7d32; }
.tag-role  { background: var(--badge-role);  color: #c62828; }
.tag-cert  { background: var(--badge-cert);  color: #6d4c41; }

/* ===== Roadmap Strip ===== */
.roadmap {
  display: flex;
  flex-direction: column;
  gap: 3px;
  margin-top: var(--space-xl);
}

.roadmap-step {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: var(--space-lg);
  background: var(--card);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-soft);
  border: 1px solid var(--hairline);
}

.roadmap-num {
  width: 40px; height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--primary);
  color: #fff;
  font-size: 16px;
  font-weight: 600;
  border-radius: var(--radius-pill);
  flex-shrink: 0;
}

.roadmap-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 4px;
}

.roadmap-desc {
  font-size: 14px;
  color: var(--body);
  line-height: 1.5;
}

/* ===== Ink Slab ===== */
.ink-slab {
  background: var(--ink);
  color: #fff;
  padding: var(--space-section) 0;
}

.ink-slab .section-title { color: #fff; }
.ink-slab .section-lead  { color: rgba(255,255,255,0.7); }

/* ===== Article Page ===== */
.page-hero {
  padding: var(--space-xxl) 0 var(--space-xl);
  background: var(--cloud);
  border-bottom: 1px solid var(--hairline);
}

.page-title {
  font-size: clamp(26px, 4vw, 44px);
  font-weight: 500;
  letter-spacing: -0.5px;
  color: var(--ink);
  line-height: 1.15;
  margin-bottom: var(--space-md);
}

.page-lead {
  font-size: 18px;
  font-weight: 400;
  color: var(--body);
  max-width: 640px;
  line-height: 1.6;
}

/* ===== Content ===== */
.content-wrapper {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: var(--space-xxl);
  padding: var(--space-xxl) 0 var(--space-section);
  align-items: start;
}

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

.content-sidebar {
  position: sticky;
  top: 80px;
}

.toc-widget {
  background: var(--card);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-soft);
  margin-bottom: var(--space-lg);
}

.toc-heading {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.7px;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: var(--space-md);
}

.toc-items { display: flex; flex-direction: column; gap: 4px; }

.toc-items a {
  font-size: 13px;
  color: var(--body);
  text-decoration: none;
  padding: 4px 0 4px 10px;
  border-left: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}

.toc-items a:hover { color: var(--ink); border-color: var(--primary); }
.toc-items a.active { color: var(--primary); border-color: var(--primary); }

.article-content h2 {
  font-size: 24px;
  font-weight: 600;
  color: var(--ink);
  margin: var(--space-xxl) 0 var(--space-md);
  scroll-margin-top: 80px;
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--hairline);
}

.article-content h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--ink);
  margin: var(--space-xl) 0 var(--space-sm);
  scroll-margin-top: 80px;
}

.article-content p {
  font-size: 16px;
  color: var(--body);
  line-height: 1.7;
  margin-bottom: var(--space-md);
}

.article-content ul, .article-content ol {
  margin: var(--space-md) 0 var(--space-md) var(--space-lg);
  list-style: disc;
}

.article-content ol { list-style: decimal; }

.article-content li {
  font-size: 16px;
  color: var(--body);
  line-height: 1.6;
  margin-bottom: 4px;
}

.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-xl) 0;
  font-size: 14px;
}

.article-content th {
  text-align: left;
  padding: 10px var(--space-md);
  background: var(--cloud);
  color: var(--ink);
  font-weight: 600;
  border-bottom: 2px solid var(--fog);
}

.article-content td {
  padding: 10px var(--space-md);
  border-bottom: 1px solid var(--hairline);
  color: var(--body);
}

.article-content tr:last-child td { border-bottom: none; }

.article-figure {
  margin: var(--space-xl) 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--hairline);
  box-shadow: var(--shadow-soft);
}

.article-figure img { width: 100%; }

.article-figure figcaption {
  font-size: 12px;
  color: var(--muted);
  padding: 8px var(--space-md);
  background: var(--cloud);
  border-top: 1px solid var(--hairline);
}

/* ===== FAQ ===== */
details.faq {
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-xs);
  overflow: hidden;
  box-shadow: var(--shadow-soft);
}

details.faq summary {
  cursor: pointer;
  padding: var(--space-md) var(--space-lg);
  font-size: 15px;
  font-weight: 600;
  color: var(--ink);
  background: var(--card);
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

details.faq summary::after {
  content: '+';
  font-size: 18px;
  color: var(--primary);
  flex-shrink: 0;
}

details.faq[open] summary::after { content: '−'; }

.faq-body {
  padding: var(--space-md) var(--space-lg);
  background: var(--cloud);
  font-size: 14px;
  color: var(--body);
  line-height: 1.6;
  border-top: 1px solid var(--hairline);
}

/* ===== Breadcrumb ===== */
.breadcrumb { padding: var(--space-md) 0; }

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  align-items: center;
  font-size: 13px;
}

.breadcrumb-item a { color: var(--muted); text-decoration: none; }
.breadcrumb-item a:hover { color: var(--primary); }
.breadcrumb-item span:not(.breadcrumb-sep) { color: var(--muted); }
.breadcrumb-sep { color: var(--hairline-str); padding: 0 4px; }

/* ===== Related ===== */
.related-section {
  margin-top: var(--space-xxl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--hairline);
}

.related-heading {
  font-size: 18px;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: var(--space-lg);
}

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

.related-card {
  display: block;
  padding: var(--space-md);
  background: var(--card);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-lg);
  text-decoration: none;
  box-shadow: var(--shadow-soft);
  transition: box-shadow 0.15s;
}

.related-card:hover { box-shadow: var(--shadow-float); text-decoration: none; }

.related-card-title {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 4px;
}

.related-card-desc {
  display: block;
  font-size: 13px;
  color: var(--muted);
}

/* ===== Footer ===== */
.site-footer {
  background: var(--ink);
  color: rgba(255,255,255,0.7);
  padding: var(--space-section) 0 var(--space-xl);
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1.5fr;
  gap: var(--space-xxl);
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  text-decoration: none;
  color: #fff;
  margin-bottom: var(--space-md);
}

.footer-logo .logo-icon { color: var(--primary); }
.footer-logo .logo-text { color: #fff; }

.footer-desc {
  font-size: 14px;
  color: rgba(255,255,255,0.5);
  line-height: 1.6;
}

.footer-copy {
  font-size: 12px;
  color: rgba(255,255,255,0.3);
  margin-top: var(--space-md);
}

.footer-nav-heading {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.7px;
  text-transform: uppercase;
  color: rgba(255,255,255,0.4);
  margin-bottom: var(--space-md);
}

.footer-nav-list { display: flex; flex-direction: column; gap: 8px; }

.footer-nav-list a {
  font-size: 14px;
  color: rgba(255,255,255,0.55);
  text-decoration: none;
}

.footer-nav-list a:hover { color: #fff; }

.footer-about {
  font-size: 14px;
  color: rgba(255,255,255,0.5);
  line-height: 1.6;
}

/* ===== Responsive ===== */
@media (max-width: 1200px) {
  .cards-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 1024px) {
  .cards-3 { grid-template-columns: repeat(2, 1fr); }
  .content-wrapper { grid-template-columns: 1fr; }
  .content-sidebar { position: static; }
  .hero-inner { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .nav-toggle { display: flex; }
  .main-nav {
    display: none;
    position: absolute;
    top: 64px; left: 0; right: 0;
    background: var(--canvas);
    border-bottom: 1px solid var(--hairline);
    padding: var(--space-md);
    z-index: 99;
  }
  .main-nav.open { display: block; }
  .nav-list { flex-direction: column; gap: 4px; }
  .nav-link { padding: 10px; font-size: 15px; }
  .cards-4, .cards-3, .cards-2 { grid-template-columns: 1fr; }
  .related-cards { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: var(--space-xl); }
  .roadmap-step { grid-template-columns: 1fr; }
}