:root {
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-text: #1a1a1a;
  --color-text-secondary: #555;
  --color-accent: #1a5276;
  --color-accent-light: #2980b9;
  --color-border: #e0e0e0;
  --color-tag-bg: #eaf2f8;
  --color-tag-text: #1a5276;
  --max-width: 860px;
  --font-body: "Source Sans 3", "Source Sans Pro", system-ui, -apple-system, sans-serif;
  --font-heading: "Playfair Display", Georgia, serif;
}

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

html {
  font-size: 17px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-accent-light);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--color-accent);
  text-decoration: underline;
}

/* ── Header / Navigation ── */

header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.site-name {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: 0.01em;
}

.site-name:hover {
  text-decoration: none;
  color: var(--color-accent);
}

nav {
  display: flex;
  gap: 0.25rem;
}

nav a {
  padding: 0.4rem 0.9rem;
  border-radius: 6px;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: background 0.2s, color 0.2s;
}

nav a:hover {
  background: var(--color-tag-bg);
  color: var(--color-accent);
  text-decoration: none;
}

nav a.active {
  background: var(--color-tag-bg);
  color: var(--color-accent);
  font-weight: 600;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--color-text);
  padding: 0.25rem;
}

/* ── Main Content ── */

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
}

/* ── Hero / Intro ── */

.hero {
  display: flex;
  gap: 2.5rem;
  align-items: center;
  margin-bottom: 3rem;
}

.hero-photo {
  flex-shrink: 0;
  align-self: center;
}

.hero-photo img {
  width: 180px;
  height: 180px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--color-border);
}

.hero-text h1 {
  font-family: var(--font-heading);
  font-size: 2rem;
  margin-bottom: 0.25rem;
  color: var(--color-text);
}

.hero-text .subtitle {
  font-size: 1.05rem;
  color: var(--color-text-secondary);
  margin-bottom: 0.75rem;
}

.hero-text .bio {
  font-size: 0.97rem;
  color: var(--color-text-secondary);
  line-height: 1.75;
}

.contact-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1rem;
}

.contact-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.88rem;
  padding: 0.3rem 0.7rem;
  border: 1px solid var(--color-border);
  border-radius: 5px;
  color: var(--color-text-secondary);
  transition: border-color 0.2s, color 0.2s;
}

.contact-links a:hover {
  border-color: var(--color-accent-light);
  color: var(--color-accent);
  text-decoration: none;
}

/* ── Section Blocks ── */

.section {
  margin-bottom: 2.5rem;
}

.section h2 {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  margin-bottom: 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--color-accent);
  display: inline-block;
}

.section h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.3rem;
}

/* ── Tags ── */

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tag {
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  padding: 0.3rem 0.75rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 500;
}

/* ── List Styles ── */

.item-list {
  list-style: none;
}

.item-list li {
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--color-border);
}

.item-list li:last-child {
  border-bottom: none;
}

.item-meta {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  margin-top: 0.15rem;
}

/* ── Publication List ── */

.pub-list {
  list-style: none;
  counter-reset: pub-counter;
}

.pub-list li {
  padding: 1rem 0;
  border-bottom: 1px solid var(--color-border);
}

.pub-list li:last-child {
  border-bottom: none;
}

.pub-title {
  font-weight: 600;
  font-size: 1rem;
  color: var(--color-text);
  line-height: 1.5;
}

.pub-title a {
  color: var(--color-text);
}

.pub-title a:hover {
  color: var(--color-accent-light);
}

.pub-authors {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-top: 0.2rem;
}

.pub-venue {
  font-size: 0.88rem;
  color: var(--color-text-secondary);
  font-style: italic;
  margin-top: 0.15rem;
}

.pub-year {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-accent);
  background: var(--color-tag-bg);
  padding: 0.1rem 0.5rem;
  border-radius: 3px;
  margin-top: 0.3rem;
}

/* ── Consulting Cards ── */

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.25rem;
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 1.5rem;
  transition: box-shadow 0.2s, border-color 0.2s;
}

.card:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
  border-color: var(--color-accent-light);
}

.card h3 {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  color: var(--color-accent);
}

.card p {
  font-size: 0.93rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
}

/* ── CTA Button ── */

.cta-section {
  text-align: center;
  margin-top: 2.5rem;
  padding: 2rem;
  background: var(--color-tag-bg);
  border-radius: 10px;
}

.cta-section p {
  font-size: 1rem;
  color: var(--color-text-secondary);
  margin-bottom: 1rem;
}

.btn {
  display: inline-block;
  padding: 0.65rem 1.5rem;
  background: var(--color-accent);
  color: #fff;
  border-radius: 6px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: background 0.2s;
}

.btn:hover {
  background: var(--color-accent-light);
  color: #fff;
  text-decoration: none;
}


/* ── Footer ── */

footer {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.5rem;
  text-align: center;
  font-size: 0.82rem;
  color: var(--color-text-secondary);
  border-top: 1px solid var(--color-border);
}

/* ── Responsive ── */

@media (max-width: 640px) {
  html {
    font-size: 16px;
  }

  .hero {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .hero-photo img {
    width: 140px;
    height: 140px;
  }

  .contact-links {
    justify-content: center;
  }

  .tags {
    justify-content: center;
  }

  .header-inner {
    position: relative;
  }

  .menu-toggle {
    display: block;
  }

  nav {
    display: none;
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background: var(--color-surface);
    flex-direction: column;
    padding: 0.5rem 1rem 1rem;
    border-bottom: 1px solid var(--color-border);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  }

  nav.open {
    display: flex;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }
}