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

:root {
  --dark: #1a1a2e;
  --darker: #16162a;
  --accent: #0f7173;
  --accent-light: #14919b;
  --text: #2d2d2d;
  --text-light: #6b6b6b;
  --bg: #ffffff;
  --bg-light: #f7f7f9;
  --border: #e2e2e8;
  --card-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  --card-shadow-hover: 0 8px 30px rgba(0, 0, 0, 0.12);
  --transition: 0.3s ease;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
}

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

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

img {
  max-width: 100%;
  height: auto;
}

/* ===== TYPOGRAPHY ===== */
h1, h2, h3, h4 {
  color: var(--dark);
  line-height: 1.2;
  font-weight: 700;
}

h1 { font-size: 3rem; }
h2 { font-size: 2rem; margin-bottom: 1rem; }
h3 { font-size: 1.35rem; margin-bottom: 0.5rem; }
h4 { font-size: 1.1rem; margin-bottom: 0.3rem; }

p { margin-bottom: 1rem; }

/* ===== LAYOUT ===== */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 2rem;
}

.section {
  padding: 5rem 0;
}

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

/* ===== NAVBAR ===== */
.navbar {
  background: var(--dark);
  padding: 0 2rem;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.15);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.navbar__logo {
  color: #fff;
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.navbar__logo:hover {
  color: var(--accent-light);
}

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

.navbar__links a {
  color: rgba(255, 255, 255, 0.85);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.5rem 0;
  position: relative;
  transition: color var(--transition);
}

.navbar__links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-light);
  transition: width var(--transition);
}

.navbar__links a:hover,
.navbar__links a.active {
  color: #fff;
}

.navbar__links a:hover::after,
.navbar__links a.active::after {
  width: 100%;
}

.navbar__toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.navbar__toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: #fff;
  margin: 5px 0;
  transition: all var(--transition);
}

/* ===== HERO ===== */
.hero {
  background: var(--dark);
  color: #fff;
  padding: 6rem 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(ellipse at center, rgba(15, 113, 115, 0.15) 0%, transparent 60%);
  pointer-events: none;
}

.hero h1 {
  color: #fff;
  font-size: 4rem;
  font-weight: 800;
  letter-spacing: 2px;
  margin-bottom: 1rem;
  text-transform: uppercase;
}

.hero__subtitle {
  font-size: 1.3rem;
  color: rgba(255, 255, 255, 0.7);
  font-weight: 400;
  letter-spacing: 1px;
  margin-bottom: 2rem;
}

.hero__tagline {
  font-size: 1.05rem;
  color: rgba(255, 255, 255, 0.55);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.6;
}

/* ===== ABOUT / BIO SECTION ===== */
.about {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 3rem;
  align-items: start;
}

.about__photo {
  width: 100%;
  border-radius: 8px;
  box-shadow: var(--card-shadow);
}

.about__text p {
  font-size: 1.05rem;
  color: var(--text);
}

/* ===== CARDS ===== */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 2rem;
  transition: all var(--transition);
}

.card:hover {
  box-shadow: var(--card-shadow-hover);
  transform: translateY(-3px);
  border-color: var(--accent);
}

.card__label {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 1rem;
}

.card__title {
  font-size: 1.2rem;
  margin-bottom: 0.75rem;
}

.card__meta {
  font-size: 0.9rem;
  color: var(--text-light);
  margin-bottom: 0.75rem;
}

.card__description {
  font-size: 0.95rem;
  color: var(--text);
  margin-bottom: 1rem;
}

.card__link {
  font-weight: 600;
  font-size: 0.9rem;
}

.card__link::after {
  content: ' \2192';
}

/* ===== HIGHLIGHT CARDS (Homepage) ===== */
.highlights {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.highlight {
  text-align: center;
  padding: 2.5rem 2rem;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 8px;
  transition: all var(--transition);
}

.highlight:hover {
  box-shadow: var(--card-shadow-hover);
  transform: translateY(-3px);
  border-color: var(--accent);
}

.highlight__icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  display: block;
}

.highlight__title {
  font-size: 1.2rem;
  margin-bottom: 0.75rem;
}

.highlight__desc {
  font-size: 0.95rem;
  color: var(--text-light);
  margin-bottom: 1.25rem;
}

/* ===== PAGE HEADER ===== */
.page-header {
  background: var(--dark);
  color: #fff;
  padding: 4rem 0;
  text-align: center;
}

.page-header h1 {
  color: #fff;
  font-size: 2.5rem;
  text-transform: uppercase;
  letter-spacing: 2px;
}

.page-header p {
  color: rgba(255, 255, 255, 0.6);
  margin-top: 0.75rem;
  font-size: 1.1rem;
}

/* ===== CV PAGE ===== */
.cv-section {
  margin-bottom: 3rem;
}

.cv-section h2 {
  font-size: 1.6rem;
  border-bottom: 3px solid var(--accent);
  padding-bottom: 0.5rem;
  margin-bottom: 1.5rem;
}

.cv-entry {
  margin-bottom: 2rem;
  padding-left: 1rem;
  border-left: 3px solid var(--border);
}

.cv-entry:hover {
  border-left-color: var(--accent);
}

.cv-entry h3 {
  font-size: 1.15rem;
  margin-bottom: 0.2rem;
}

.cv-entry .cv-meta {
  font-size: 0.9rem;
  color: var(--text-light);
  font-style: italic;
  margin-bottom: 0.5rem;
}

.cv-entry .cv-date {
  font-size: 0.85rem;
  color: var(--accent);
  font-weight: 600;
}

.cv-entry p, .cv-entry ul {
  font-size: 0.95rem;
  margin-top: 0.5rem;
}

.cv-entry ul {
  padding-left: 1.25rem;
}

.cv-entry ul li {
  margin-bottom: 0.3rem;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-block;
  padding: 0.75rem 1.75rem;
  border-radius: 6px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
  text-align: center;
}

.btn--primary {
  background: var(--accent);
  color: #fff;
}

.btn--primary:hover {
  background: var(--accent-light);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(15, 113, 115, 0.3);
}

.btn--outline {
  border: 2px solid var(--accent);
  color: var(--accent);
  background: transparent;
}

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

/* ===== CONTACT ===== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.contact-item {
  text-align: center;
  padding: 2rem;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 8px;
  transition: all var(--transition);
}

.contact-item:hover {
  box-shadow: var(--card-shadow-hover);
  border-color: var(--accent);
}

.contact-item__icon {
  font-size: 2rem;
  margin-bottom: 0.75rem;
  display: block;
}

.contact-item--photo {
  padding: 0;
  overflow: hidden;
  min-height: 200px;
}

.contact-item__label {
  font-weight: 600;
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}

/* ===== FOOTER ===== */
.footer {
  background: var(--dark);
  color: rgba(255, 255, 255, 0.6);
  padding: 3rem 0;
  text-align: center;
  font-size: 0.9rem;
}

.footer a {
  color: rgba(255, 255, 255, 0.8);
}

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

.footer__links {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-bottom: 1.5rem;
  list-style: none;
}

.footer__note {
  font-style: italic;
  color: rgba(255, 255, 255, 0.35);
  margin-top: 1rem;
}

/* ===== PUBLICATION LIST ===== */
.pub-list {
  list-style: none;
}

.pub-list li {
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--border);
}

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

.pub-title {
  font-weight: 600;
}

.pub-journal {
  font-style: italic;
  color: var(--text-light);
}

.pub-status {
  display: inline-block;
  background: var(--bg-light);
  font-size: 0.8rem;
  padding: 0.15rem 0.6rem;
  border-radius: 12px;
  color: var(--text-light);
  margin-left: 0.5rem;
}

/* ===== ANIMATIONS ===== */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 2.5rem;
  }

  .hero__subtitle {
    font-size: 1.1rem;
  }

  h1 { font-size: 2.2rem; }
  h2 { font-size: 1.6rem; }

  .about {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .about__photo {
    max-width: 250px;
    margin: 0 auto;
  }

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

  .research-intro {
    grid-template-columns: 1fr !important;
  }

  .research-intro img {
    max-width: 400px;
    margin: 0 auto;
  }

  .navbar__links {
    display: none;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--dark);
    flex-direction: column;
    padding: 1rem 2rem 2rem;
    gap: 0;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
  }

  .navbar__links.open {
    display: flex;
  }

  .navbar__links li {
    padding: 0.75rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }

  .navbar__toggle {
    display: block;
  }

  .section {
    padding: 3rem 0;
  }

  .page-header {
    padding: 3rem 0;
  }

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

  .footer__links {
    flex-direction: column;
    gap: 0.75rem;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 2rem;
  }

  .container {
    padding: 0 1.25rem;
  }

  .card {
    padding: 1.5rem;
  }
}