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

:root {
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --text: #0f172a;
  --muted: #64748b;
  --accent: #1e40af;
  --badge-bg: #f1f5f9;
  --badge-text: #475569;
  --border: #e2e8f0;
  --font: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

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

/* ── NAV ── */

nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 56px;
}

.nav-brand {
  font-weight: 700;
  font-size: 1rem;
  color: var(--text);
  text-decoration: none;
  white-space: nowrap;
  padding: 0.75rem 0;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: var(--muted);
  font-size: 0.9375rem;
  transition: color 0.15s;
}

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

@media (max-width: 600px) {
  nav {
    flex-wrap: wrap;
    padding: 0.5rem 1rem;
    gap: 0;
  }

  .nav-brand {
    flex: 1 0 100%;
    padding: 0.375rem 0;
  }

  .nav-links {
    flex: 1 0 100%;
    gap: 0.875rem;
    padding-bottom: 0.5rem;
    flex-wrap: wrap;
  }

  .nav-links a {
    font-size: 0.875rem;
  }
}

/* ── LAYOUT ── */

main {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem 1.5rem 5rem;
}

/* ── HERO ── */

.hero {
  padding: 4rem 0 3.5rem;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 0.75rem;
}

.hero .tagline {
  font-size: 1.125rem;
  color: var(--muted);
  margin-bottom: 1.75rem;
  max-width: 480px;
}

/* ── BUTTON ── */

.btn {
  display: inline-block;
  padding: 0.625rem 1.25rem;
  background: var(--accent);
  color: #fff;
  border-radius: 6px;
  text-decoration: none;
  font-size: 0.9375rem;
  font-weight: 600;
  transition: opacity 0.15s;
}

.btn:hover {
  opacity: 0.85;
}

/* ── SECTION LABEL ── */

.section-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--muted);
  margin-bottom: 1rem;
}

/* ── HIGHLIGHT CARDS ── */

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1.25rem;
}

.card {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem;
  text-decoration: none;
  color: inherit;
  background: var(--bg);
  transition: border-color 0.15s, box-shadow 0.15s;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.card:hover {
  border-color: var(--accent);
  box-shadow: 0 2px 10px rgba(30, 64, 175, 0.08);
}

.card-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  font-weight: 700;
}

.card h3 {
  font-size: 1rem;
  font-weight: 700;
}

.card p {
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.5;
}

/* ── PAGE HEADER ── */

.page-header {
  padding: 2.5rem 0 2rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 3rem;
}

.page-header h1 {
  font-size: 2rem;
  font-weight: 800;
}

/* ── ENTRY ── */

.entry {
  margin-bottom: 3rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid var(--border);
}

.entry:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.entry-title {
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.3;
}

.entry-title-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.625rem;
  margin-bottom: 0.2rem;
}

.entry-org {
  font-size: 1rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.15rem;
}

.entry-meta {
  font-size: 0.875rem;
  color: var(--muted);
  margin-bottom: 1rem;
}

.entry-summary {
  color: var(--muted);
  margin-bottom: 1rem;
  line-height: 1.65;
}

/* ── BADGES ── */

.badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem;
  margin-bottom: 1.125rem;
}

.badge {
  background: var(--badge-bg);
  color: var(--badge-text);
  font-size: 0.8125rem;
  padding: 0.2rem 0.625rem;
  border-radius: 999px;
  font-weight: 500;
  line-height: 1.6;
}

.badge-status {
  background: #dcfce7;
  color: #166534;
}

/* ── HIGHLIGHTS ── */

ul.highlights {
  padding-left: 1.25rem;
  margin-bottom: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

ul.highlights li {
  font-size: 0.9375rem;
  line-height: 1.6;
}

/* ── DEEP DIVE ── */

details {
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

details summary {
  cursor: pointer;
  padding: 0.75rem 1rem;
  font-weight: 600;
  font-size: 0.9375rem;
  background: var(--bg-alt);
  user-select: none;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

details summary::-webkit-details-marker {
  display: none;
}

details summary::before {
  content: '+';
  font-size: 1.125rem;
  color: var(--accent);
  font-weight: 700;
  width: 1rem;
  text-align: center;
  flex-shrink: 0;
}

details[open] summary::before {
  content: '-';
}

.details-body {
  padding: 1.25rem;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--muted);
  border-top: 1px solid var(--border);
}

.details-body p + p {
  margin-top: 0.875rem;
}

.details-body h4 {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--text);
  margin-top: 1.125rem;
  margin-bottom: 0.375rem;
}

.details-body h4:first-child {
  margin-top: 0;
}

/* ── ABOUT ── */

.about-body {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  max-width: 680px;
}

.about-body p {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--text);
}

.cert-card {
  margin-top: 2.5rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem 1.25rem;
  background: var(--bg-alt);
  display: inline-flex;
  flex-direction: column;
  gap: 0.2rem;
}

.cert-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--accent);
  margin-bottom: 0.25rem;
}

.cert-name {
  font-weight: 700;
  font-size: 0.9375rem;
  color: var(--text);
}

.cert-meta {
  font-size: 0.875rem;
  color: var(--muted);
}

/* ── CONTACT ── */

.contact-intro {
  font-size: 1rem;
  color: var(--muted);
  margin-top: 0.25rem;
  margin-bottom: 2rem;
}

.contact-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.contact-item {
  display: flex;
  flex-direction: column;
  gap: 0.125rem;
}

.contact-item a {
  text-decoration: none;
  color: var(--accent);
  font-size: 1rem;
  font-weight: 600;
}

.contact-item a:hover {
  text-decoration: underline;
}

.contact-desc {
  font-size: 0.8125rem;
  color: var(--muted);
}