/* ── RESET & BASE ──────────────────────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --navy:      #1a2744;
  --accent:    #2a5298;
  --accent-lt: #e8eef8;
  --text:      #1c1c1e;
  --muted:     #6b7280;
  --border:    #e5e7eb;
  --bg:        #ffffff;
  --bg-alt:    #f8f9fb;

  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-serif: 'Lora', Georgia, serif;

  --max-w: 860px;
  --radius: 6px;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

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

/* ── UTILITIES ─────────────────────────────────────────────────────────────── */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section-title {
  font-family: var(--font-serif);
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: 2rem;
  padding-bottom: .6rem;
  border-bottom: 2px solid var(--border);
}

.btn {
  display: inline-block;
  padding: .5rem 1.1rem;
  background: var(--accent);
  color: #fff;
  border-radius: var(--radius);
  font-size: .875rem;
  font-weight: 500;
  text-decoration: none;
  transition: background .2s, transform .1s;
}
.btn:hover { background: var(--navy); transform: translateY(-1px); }

.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 1.5px solid var(--accent);
}
.btn-outline:hover { background: var(--accent-lt); color: var(--navy); border-color: var(--navy); }

.btn-disabled {
  background: transparent;
  color: var(--border);
  border: 1.5px solid var(--border);
  cursor: default;
  position: relative;
}
.btn-disabled:hover::after,
.paper-link-disabled:hover::after,
.link-disabled:hover::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 6px);
  left: 50%;
  transform: translateX(-50%);
  background: var(--navy);
  color: #fff;
  font-size: .75rem;
  white-space: nowrap;
  padding: .3rem .6rem;
  border-radius: 4px;
  pointer-events: none;
  z-index: 10;
}
.btn-disabled:hover { background: transparent; transform: none; }

.btn-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.1rem;
  height: 2.1rem;
  border-radius: 50%;
  border: 1.5px solid var(--accent);
  color: var(--accent);
  font-size: 1rem;
  text-decoration: none;
  transition: background .2s, color .2s, border-color .2s, transform .1s;
}
.btn-icon:hover {
  background: var(--accent);
  color: #fff;
  transform: translateY(-1px);
}

/* ── NAV ───────────────────────────────────────────────────────────────────── */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

header nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.nav-name {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--navy);
  text-decoration: none;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 2rem;
}

.nav-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: .9rem;
  font-weight: 500;
  transition: color .15s;
}
.nav-links a:hover { color: var(--accent); }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.3rem;
  cursor: pointer;
  color: var(--navy);
}

/* ── HERO ──────────────────────────────────────────────────────────────────── */
.hero {
  padding: 5rem 0 4rem;
  background: var(--bg);
}

.hero-inner {
  display: grid;
  grid-template-columns: 170px 1fr;
  gap: 3rem;
  align-items: start;
}

.hero-photo img {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center top;
  border: 2px solid var(--border);
  display: block;
}

.hero-text h1 {
  font-family: var(--font-serif);
  font-size: 2.2rem;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: .3rem;
}

.subtitle {
  font-size: .95rem;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 1.2rem;
  letter-spacing: .01em;
}

.bio {
  color: var(--text);
  font-size: .95rem;
  line-height: 1.75;
  margin-bottom: .9rem;
}

.hero-links {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1.4rem;
}

.hero-links-row {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: .45rem;
}

.hero-links-row .hero-links-btns {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: .6rem;
}

.links-label {
  font-size: .68rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ── RESEARCH ──────────────────────────────────────────────────────────────── */
#research {
  background: var(--bg-alt);
  padding: 4rem 0;
}

.research-area {
  margin-bottom: 2.8rem;
}

.area-label {
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 1rem;
}

.paper {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem 1.75rem;
  margin-bottom: 1rem;
  transition: box-shadow .2s;
}
.paper:hover { box-shadow: 0 4px 16px rgba(0,0,0,.07); }

.paper-meta {
  display: flex;
  align-items: center;
  gap: .75rem;
  margin-bottom: .6rem;
  flex-wrap: wrap;
}

.paper-status {
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .05em;
  text-transform: uppercase;
  padding: .2rem .55rem;
  border-radius: 20px;
}
.working-paper  { background: #fef3c7; color: #92400e; }
.data-collection { background: #e0f2fe; color: #075985; }
.lit-review     { background: #e0e7ff; color: #3730a3; }
.published      { background: #d1fae5; color: #065f46; }
.under-review   { background: #fee2e2; color: #991b1b; }

.paper-target {
  font-size: .82rem;
  color: var(--muted);
}

.paper-title {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--navy);
  margin-bottom: .25rem;
  line-height: 1.4;
}

.paper-authors {
  font-size: .85rem;
  color: var(--muted);
  margin-bottom: .8rem;
}

.paper-abstract {
  font-size: .9rem;
  color: var(--text);
  line-height: 1.7;
  margin-bottom: 1rem;
}

.paper-links {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
}

.paper-link {
  font-size: .8rem;
  font-weight: 500;
  color: var(--accent);
  text-decoration: none;
  border: 1px solid var(--accent);
  padding: .2rem .6rem;
  border-radius: 4px;
  transition: background .15s, color .15s;
}
.paper-link:hover { background: var(--accent); color: #fff; }

.paper-link-disabled {
  font-size: .8rem;
  font-weight: 500;
  color: var(--border);
  border: 1px solid var(--border);
  padding: .2rem .6rem;
  border-radius: 4px;
  cursor: default;
  position: relative;
}

.link-disabled {
  color: var(--border);
  cursor: default;
  position: relative;
  text-decoration: none;
}

/* ── CV ────────────────────────────────────────────────────────────────────── */
.cv-section {
  padding: 4rem 0;
  background: var(--bg);
}

.cv-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem 3rem;
  margin-bottom: 2.5rem;
}

.cv-block h3 {
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 1rem;
  padding-bottom: .4rem;
  border-bottom: 1px solid var(--border);
}

.cv-item {
  display: flex;
  gap: 1rem;
  margin-bottom: 1rem;
  font-size: .9rem;
}

.cv-year {
  flex-shrink: 0;
  width: 70px;
  color: var(--muted);
  font-size: .8rem;
  padding-top: .1rem;
}

.cv-detail {
  font-size: .82rem;
  color: var(--muted);
}

.cv-list {
  list-style: none;
  font-size: .9rem;
}
.cv-list li {
  padding: .3rem 0;
  border-bottom: 1px solid var(--border);
  color: var(--text);
}
.cv-list li::before {
  content: '→  ';
  color: var(--accent);
  font-size: .8rem;
}

.cv-download {
  text-align: center;
  margin-top: 1rem;
}

/* ── CONTACT ───────────────────────────────────────────────────────────────── */
#contact {
  background: var(--bg-alt);
  padding: 4rem 0;
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}
.contact-grid-2 {
  grid-template-columns: repeat(2, 1fr);
  max-width: 580px;
}

.contact-block h3 {
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: .8rem;
}

.contact-block p {
  font-size: .9rem;
  line-height: 1.9;
}

.contact-block a {
  color: var(--accent);
  text-decoration: none;
}
.contact-block a:hover { text-decoration: underline; }

.contact-note {
  font-size: .85rem;
  color: var(--muted);
  margin-top: .5rem;
  line-height: 1.6;
}

/* ── FOOTER ────────────────────────────────────────────────────────────────── */
footer {
  background: var(--navy);
  color: rgba(255,255,255,.5);
  text-align: center;
  padding: 1.5rem;
  font-size: .82rem;
}

/* ── RESPONSIVE ────────────────────────────────────────────────────────────── */
@media (max-width: 680px) {
  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-photo {
    display: flex;
    justify-content: center;
  }
  .hero-links {
    justify-content: center;
  }

  .cv-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

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

  .nav-links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 1rem 1.5rem;
    gap: 1rem;
  }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; }

  header { position: relative; }
}