/* ============================================================
   layout.css — Page structure, grid, navigation, sections
   ============================================================ */

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

/* --- Section spacing ----------------------------------- */
.section {
  padding: 4rem 0;
}
.section--first {
  padding: 3.5rem 0 2rem;
}

/* --- Section title with decorative line --------------- */
.section__title {
  font-family: var(--font-heading);
  font-size: 1.45rem;
  font-weight: 500;
  color: var(--color-text-heading);
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.25rem;
}
.section__title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--color-border);
}

/* --- Navigation ---------------------------------------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(253, 252, 251, 0.88);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  height: 56px;
}
[data-theme="dark"] .nav {
  background: rgba(23, 20, 26, 0.88);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.nav__brand {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1.25rem;
  color: var(--color-text-heading);
  letter-spacing: -0.02em;
  flex-shrink: 0;
}
.nav__brand:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 0.15rem;
  list-style: none;
  padding: 0;
  margin: 0;
}
.nav__links li { margin: 0; }

.nav__link {
  display: block;
  padding: 0.3rem 0.7rem;
  border-radius: var(--radius);
  font-size: 0.88rem;
  color: var(--color-text-secondary);
  font-weight: 500;
  transition: background 0.15s, color 0.15s;
}
.nav__link:hover,
.nav__link--active {
  color: var(--color-accent);
  background: var(--color-accent-subtle);
  text-decoration: none;
}

.nav__toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.25rem;
  color: var(--color-text);
}
.nav__toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  margin: 5px 0;
  border-radius: 1px;
  transition: 0.2s;
}

.nav__theme-btn {
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  cursor: pointer;
  padding: 0.3rem 0.5rem;
  font-size: 1rem;
  color: var(--color-text-secondary);
  transition: all 0.15s;
  line-height: 1;
  margin-left: 0.25rem;
}
.nav__theme-btn:hover {
  background: var(--color-bg-warm);
  color: var(--color-text);
  border-color: var(--color-text-tertiary);
}

/* Nav spacer since nav is fixed */
.nav-spacer {
  height: 56px;
}

/* --- Hero (Home) section ------------------------------- */
.hero {
  display: flex;
  gap: 2.5rem;
  align-items: flex-start;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--color-border-light);
}

.hero__avatar {
  flex-shrink: 0;
  width: 220px;
  height: 293px;
  border-radius: 12px;
  background: var(--color-bg-warm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-size: 4rem;
  font-weight: 600;
  color: var(--color-text-tertiary);
  overflow: hidden;
  border: 1px solid var(--color-border-light);
}
.hero__avatar-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero__text { flex: 1; }

.hero__name {
  margin-bottom: 0.1rem;
  font-size: 2.6rem;
}
.hero__title {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-style: italic;
  color: var(--color-text-secondary);
  margin-bottom: 0.15rem;
  font-weight: 400;
}
.hero__affiliation {
  font-size: 0.9rem;
  color: var(--color-text-tertiary);
  margin-bottom: 0.5rem;
}
.hero__research {
  list-style: disc;
  padding-left: 1.25rem;
  margin-bottom: 0.75rem;
  font-size: 0.93rem;
  color: var(--color-text-secondary);
}
.hero__research li { margin-bottom: 0.15rem; }
.hero__email {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-bottom: 0.6rem;
}

/* Bio / self-introduction */
.bio {
  margin-top: 1.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--color-border-light);
}
.bio p {
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--color-text-secondary);
  margin-bottom: 0.85rem;
}

/* Social links in hero */
.social {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  list-style: none;
  padding: 0;
  margin: 0;
}
.social__link {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.2rem 0.65rem;
  border-radius: var(--radius);
  font-size: 0.82rem;
  font-weight: 500;
  background: var(--color-bg-warm);
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border-light);
  transition: all 0.15s;
}
.social__link:hover {
  background: var(--color-accent-subtle);
  color: var(--color-accent);
  border-color: var(--color-accent);
  text-decoration: none;
}

.social__icon {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

/* --- Publications filter tabs -------------------------- */
.filter {
  display: flex;
  gap: 0.35rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}
.filter__btn {
  padding: 0.35rem 0.9rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-surface);
  color: var(--color-text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s;
  font-family: var(--font-body);
}
.filter__btn:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}
.filter__btn--active {
  background: var(--color-accent);
  color: #fff;
  border-color: var(--color-accent);
}
.filter__btn--active:hover {
  background: var(--color-accent-hover);
  color: #fff;
}

/* --- Publications list -------------------------------- */
.publication {
  list-style: none;
  padding: 0;
  margin: 0;
}

.publication__card {
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius);
  margin-bottom: 0.55rem;
  background: var(--color-surface);
  transition: all 0.2s;
}
.publication__card:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-md);
}

.publication__main {
  display: flex;
  gap: 24px;
  padding: 1rem 1.25rem;
  cursor: pointer;
  user-select: none;
}

.publication__thumbnail-link {
  flex-shrink: 0;
  display: block;
}

.publication__thumbnail {
  display: block;
  height: 120px;
  width: auto;
  max-width: 160px;
  object-fit: cover;
  border-radius: 3px;
  background: var(--color-bg-warm);
  border: 1px solid var(--color-border-light);
  transition: opacity 0.2s;
}
.publication__thumbnail:hover {
  opacity: 0.85;
}

.publication__info { flex: 1; min-width: 0; }

.publication__title {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1rem;
  margin: 0 0 0.2rem;
  color: var(--color-text-heading);
}
.publication__authors {
  font-size: 0.88rem;
  color: var(--color-text-secondary);
  margin: 0.15rem 0;
}
.publication__author--self {
  color: var(--color-accent);
  font-weight: 600;
}
.publication__venue {
  font-size: 0.82rem;
  color: var(--color-text-tertiary);
  font-style: italic;
  margin: 0 0 0.3rem;
}
.publication__links {
  display: flex;
  gap: 0.35rem;
  margin-top: 0.4rem;
}
.publication__link {
  font-size: 0.78rem;
  padding: 0.15rem 0.55rem;
  border-radius: 3px;
  background: var(--color-bg-warm);
  color: var(--color-text-secondary);
  font-weight: 500;
  border: 1px solid var(--color-border-light);
  transition: all 0.15s;
}
.publication__link:hover {
  background: var(--color-navy-subtle);
  color: var(--color-navy);
  border-color: var(--color-navy);
  text-decoration: none;
}

.publication__abstract {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  border-top: 0px solid var(--color-border-light);
  padding: 0 1.25rem;
}
.publication__card--open .publication__abstract {
  max-height: 300px;
  border-top-width: 1px;
  padding: 0.85rem 1.25rem;
}
.publication__abstract-text {
  font-size: 0.88rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* --- CV section ---------------------------------------- */
.cv__download {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.35rem;
  background: var(--color-accent);
  color: #fff;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  transition: background 0.2s;
  margin-bottom: 2rem;
}
.cv__download:hover {
  background: var(--color-accent-hover);
  color: #fff;
  text-decoration: none;
}

.cv__section { margin-bottom: 1.5rem; }
.cv__section-title {
  font-size: 1.25rem;
  font-weight: 600;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--color-navy);
  display: inline-block;
  margin: 1.5rem 0 0.75rem;
}
.cv__entry {
  margin-bottom: 1.2rem;
  padding-left: 1rem;
  border-left: 2px solid var(--color-border-light);
  transition: border-color 0.2s;
}
.cv__entry:hover {
  border-left-color: var(--color-accent);
}
.cv__entry-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.cv__entry-title {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--color-text-heading);
  margin: 0;
}
.cv__entry-subtitle {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin: 0.1rem 0;
}
.cv__entry-date {
  font-size: 0.8rem;
  color: var(--color-text-tertiary);
  white-space: nowrap;
  font-family: var(--font-mono);
  font-weight: 500;
}
.cv__entry-desc {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-top: 0.35rem;
  line-height: 1.7;
}
.cv__entry-desc ul {
  margin-bottom: 0;
  padding-left: 1rem;
}

/* --- Back to top --------------------------------------- */
.back-to-top {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text-tertiary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  opacity: 0;
  transform: translateY(10px);
  transition: all 0.25s;
  z-index: 50;
  box-shadow: var(--shadow-sm);
}
.back-to-top--visible {
  opacity: 1;
  transform: translateY(0);
}
.back-to-top:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  box-shadow: var(--shadow);
}

/* --- Footer -------------------------------------------- */
.footer {
  margin-top: 3rem;
  padding: 2rem 0;
  border-top: 1px solid var(--color-border-light);
  text-align: center;
}
.footer__links {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  list-style: none;
  padding: 0;
  margin: 0 0 0.5rem;
}
.footer__link {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  font-weight: 500;
}
.footer__link:hover {
  color: var(--color-accent);
}
.footer__updated {
  font-size: 0.78rem;
  color: var(--color-text-tertiary);
  font-style: italic;
}

/* --- Responsive ---------------------------------------- */
@media (max-width: 768px) {
  .nav__links {
    display: none;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: 0.5rem 0;
    gap: 0;
  }
  .nav__links--open {
    display: flex;
  }
  .nav__link {
    padding: 0.6rem 1.5rem;
    border-radius: 0;
  }
  .nav__toggle {
    display: block;
  }

  h1 { font-size: 2rem; }

  .hero {
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 1.25rem;
  }
  .hero__avatar {
    width: 180px;
    height: 240px;
  }
  .hero__research {
    text-align: left;
  }
  .social {
    justify-content: center;
  }

  .publication__main {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  .publication__thumbnail {
    height: 100px;
    max-width: 140px;
  }
  .publication__links {
    justify-content: center;
  }

  .cv__entry-header {
    flex-direction: column;
    gap: 0.1rem;
  }
}