/* Hendrik Jansen — Unique Sticky Side Navigation + Split Hero Layout | Nordic Ice & Sky Blue Palette | Sharp Modern UI */
:root {
  --bg: #f1f5f9;
  --surface: #ffffff;
  --text: #0f172a;
  --text-muted: #64748b;
  --accent: #0ea5e9;
  --accent-dark: #0284c8;
  --border: #e2e8f0;
  --nav-bg: #0f172a;
  --nav-text: #e2e8f0;
  --shadow: 0 4px 12px rgba(15, 23, 42, 0.06);
  --radius: 4px;
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 15.5px;
  display: grid;
  grid-template-columns: 260px 1fr;
  min-height: 100vh;
}

/* Sticky Left Navigation — Documentation style, unique to this site */
nav {
  background: var(--nav-bg);
  color: var(--nav-text);
  padding: 2rem 1.5rem;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  border-right: 1px solid #1e2937;
  z-index: 50;
}

.nav-inner {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.logo {
  font-size: 1.55rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 2.5rem;
  letter-spacing: -0.3px;
  text-decoration: none;
}

.nav-menu {
  list-style: none;
  margin-bottom: auto;
}

.nav-menu li {
  margin-bottom: 0.35rem;
}

.nav-menu a {
  display: block;
  color: #cbd5e1;
  padding: 0.65rem 1rem;
  border-radius: 4px;
  font-size: 0.95rem;
  transition: all 0.15s ease;
}

.nav-menu a:hover,
.nav-menu a.active {
  background: #1e2937;
  color: #fff;
}

.nav-footer {
  font-size: 0.75rem;
  color: #64748b;
  padding-top: 1.5rem;
  border-top: 1px solid #334155;
}

@media (max-width: 900px) {
  body {
    grid-template-columns: 1fr;
  }
  nav {
    position: static;
    height: auto;
    border-right: none;
    border-bottom: 1px solid #1e2937;
    padding: 1.25rem 1rem;
  }
  .nav-inner {
    flex-direction: row;
    align-items: center;
    gap: 2rem;
  }
  .logo {
    margin-bottom: 0;
    font-size: 1.35rem;
  }
  .nav-menu {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 0;
  }
  .nav-menu li {
    margin-bottom: 0;
  }
  .nav-menu a {
    padding: 0.5rem 0.85rem;
    font-size: 0.9rem;
  }
  .nav-footer {
    display: none;
  }
}

/* Main content area */
main {
  padding: 2.5rem 3rem 4rem;
  max-width: 1100px;
  margin: 0 auto;
  width: 100%;
}

@media (max-width: 900px) {
  main {
    padding: 1.75rem 1.25rem 3rem;
  }
}

/* Hero — Split style for uniqueness */
.hero {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 2.5rem;
  align-items: center;
  margin-bottom: 4rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid var(--border);
}

@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 1.75rem;
  }
}

.hero-text h1 {
  font-size: 2.85rem;
  line-height: 1.15;
  margin-bottom: 1.25rem;
  font-weight: 700;
}

.hero-text p {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 38ch;
}

.hero-visual {
  background: linear-gradient(135deg, #0ea5e9 0%, #0284c8 100%);
  border-radius: 8px;
  height: 320px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  position: relative;
  overflow: hidden;
}

.hero-visual::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 20%, rgba(255,255,255,0.25) 0%, transparent 60%);
}

.hero-visual span {
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: 3px;
  text-transform: uppercase;
  opacity: 0.95;
}

/* Long intro text */
.intro {
  max-width: 72ch;
  margin-bottom: 4.5rem;
}

.intro h2 {
  font-size: 1.65rem;
  margin-bottom: 1.35rem;
  font-weight: 600;
}

.intro p {
  margin-bottom: 1.15rem;
  color: #334155;
}

/* Articles section header */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.75rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.section-header h3 {
  font-size: 1.75rem;
  font-weight: 600;
}

/* Article grid — clean 3-col with subtle asymmetry via content */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-bottom: 4rem;
}

.article-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.65rem 1.5rem;
  display: flex;
  flex-direction: column;
  transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
  box-shadow: var(--shadow);
  text-decoration: none;
  color: inherit;
}

.article-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 20px rgba(15, 23, 42, 0.08);
  border-color: #cbd5e1;
}

.article-card h4 {
  font-size: 1.15rem;
  margin-bottom: 0.85rem;
  line-height: 1.35;
  font-weight: 600;
}

.article-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
  flex: 1;
  margin-bottom: 1.25rem;
}

.article-card .meta {
  font-size: 0.8rem;
  color: #94a3b8;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

/* Featured block — asymmetric emphasis */
.featured {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.25rem;
  margin-bottom: 3.5rem;
  box-shadow: var(--shadow);
}

.featured h3 {
  font-size: 1.45rem;
  margin-bottom: 1rem;
}

.featured p {
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

/* Buttons — sharp square with thin border accent */
.btn {
  display: inline-block;
  background: var(--accent);
  color: white;
  padding: 0.7rem 1.65rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.9rem;
  text-decoration: none;
  transition: background 0.15s ease;
  border: none;
  cursor: pointer;
}

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

.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 1.5px solid var(--accent);
  padding: 0.65rem 1.5rem;
}

.btn-outline:hover {
  background: var(--accent);
  color: white;
}

/* Contact form */
.contact-form {
  max-width: 620px;
  background: var(--surface);
  padding: 2.5rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  margin: 2rem 0;
}

.form-group {
  margin-bottom: 1.35rem;
}

.form-group label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.45rem;
  font-size: 0.9rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.85rem 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: inherit;
  font-size: 1rem;
  background: #fff;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.1);
}

.form-group textarea {
  min-height: 140px;
  resize: vertical;
}

/* Thank you page */
.thankyou {
  max-width: 680px;
  margin: 3rem auto;
  padding: 0 1rem;
}

.thankyou h1 {
  font-size: 2.4rem;
  margin-bottom: 1rem;
}

.thankyou-content {
  background: var(--surface);
  padding: 2.5rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

/* Legal pages */
.legal {
  max-width: 780px;
  margin: 2.5rem auto;
  padding: 2.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.legal h1 {
  font-size: 2.1rem;
  margin-bottom: 0.4rem;
}

.legal .date {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-bottom: 2rem;
}

.legal h2 {
  font-size: 1.25rem;
  margin: 2rem 0 0.85rem;
  color: var(--accent);
}

.legal p, .legal li {
  margin-bottom: 0.85rem;
}

.legal ul {
  padding-left: 1.25rem;
}

/* Footer */
footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 3rem 2rem 2rem;
  margin-top: 5rem;
  font-size: 0.9rem;
  grid-column: 1 / -1;
}

.footer-content {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 2.5rem;
}

@media (max-width: 768px) {
  .footer-content {
    grid-template-columns: 1fr;
  }
}

.footer-col h5 {
  color: #e2e8f0;
  font-size: 0.95rem;
  margin-bottom: 1rem;
  font-weight: 600;
}

.footer-col a {
  color: #94a3b8;
  display: block;
  margin-bottom: 0.4rem;
  text-decoration: none;
}

.footer-col a:hover {
  color: #cbd5e1;
}

.footer-bottom {
  max-width: 1100px;
  margin: 2.5rem auto 0;
  padding-top: 1.75rem;
  border-top: 1px solid #334155;
  text-align: center;
  font-size: 0.8rem;
  color: #64748b;
}

.footer-bottom a {
  color: #94a3b8;
  margin: 0 0.3rem;
}

/* Article detail pages */
.article {
  max-width: 720px;
  margin: 0 auto;
  padding: 1rem 0 3rem;
}

.article h1 {
  font-size: 2.35rem;
  margin-bottom: 0.6rem;
  line-height: 1.25;
}

.article-meta {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-bottom: 2rem;
}

.article-body {
  font-size: 1.02rem;
}

.article-body h2 {
  margin: 2rem 0 1rem;
  font-size: 1.35rem;
}

.article-body p {
  margin-bottom: 1.1rem;
}

.back {
  display: inline-block;
  margin-bottom: 2rem;
  color: var(--accent);
  font-weight: 500;
  text-decoration: none;
}

.back:hover {
  text-decoration: underline;
}

/* Subtle decorative line */
.divider {
  height: 1px;
  background: linear-gradient(to right, transparent, var(--border), transparent);
  margin: 3rem 0;
}