/* Reset & Base */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --brown: #4E3629;
  --brown-light: #6B4C3B;
  --bg-home: #F1ECE7;
  --bg-page: #ffffff;
  --text-primary: #2C2220;
  --text-secondary: #8C7E78;
  --border-color: rgba(78, 54, 41, 0.1);
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --max-width: 1200px;
  --side-padding: 8vw;
}

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

body {
  font-family: var(--font-main);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

/* ─── Navbar ─── */
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.4rem var(--side-padding);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: transparent;
}

.navbar.page-nav {
  background: var(--bg-page);
  border-bottom: 1px solid var(--border-color);
}

.navbar .site-name {
  font-size: 1rem;
  font-weight: 400;
  letter-spacing: 0.01em;
}

.navbar nav {
  display: flex;
  gap: 2rem;
}

.navbar nav a {
  font-size: 0.9rem;
  font-weight: 400;
  transition: opacity 0.2s;
}

.navbar nav a:hover {
  opacity: 0.6;
}

.navbar nav a.active {
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-color: var(--brown);
}

/* ─── Homepage ─── */
.home-page {
  background: var(--bg-home);
  min-height: 100vh;
}

.home-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: 100vh;
  padding: 0 var(--side-padding);
  max-width: var(--max-width);
  margin: 0 auto;
  align-items: center;
  gap: 4rem;
}

.home-left {
  padding-top: 5rem;
}

.home-left h1 {
  font-size: 3rem;
  font-weight: 400;
  line-height: 1.15;
  margin-bottom: 1.5rem;
  letter-spacing: -0.02em;
}

.home-left .bio {
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.7;
  max-width: 460px;
  margin-bottom: 3rem;
  color: var(--text-primary);
}

.home-left .bio p + p {
  margin-top: 0.8rem;
}

.contact-info {
  margin-bottom: 2rem;
}

.contact-info p {
  margin-bottom: 0.4rem;
}

.contact-info a {
  font-size: 0.95rem;
  color: var(--brown-light);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.contact-info a:hover {
  opacity: 0.6;
}

.nav-links {
  display: flex;
  flex-direction: column;
  gap: 1.8rem;
}

.nav-links a {
  font-size: 1rem;
  font-weight: 700;
  transition: opacity 0.2s;
}

.nav-links a:hover {
  opacity: 0.6;
}

.home-right {
  display: flex;
  align-items: center;
  justify-content: center;
  padding-top: 5rem;
}

.home-right img {
  width: 100%;
  max-width: 480px;
  height: auto;
  object-fit: cover;
  aspect-ratio: 3 / 4;
}

/* ─── Inner Pages ─── */
.inner-page {
  background: var(--bg-page);
  min-height: 100vh;
  padding-top: 5rem;
}

.page-hero {
  height: 320px;
  background-size: cover;
  background-position: center 40%;
  display: flex;
  align-items: flex-end;
  padding: 2rem var(--side-padding);
  position: relative;
}

.page-hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(44, 34, 32, 0.55), rgba(44, 34, 32, 0.1));
}

.page-hero h1 {
  position: relative;
  z-index: 1;
  color: #fff;
  font-size: 2.8rem;
  font-weight: 400;
  letter-spacing: -0.02em;
  margin: 0;
}

.page-content {
  max-width: 750px;
  padding: 3rem var(--side-padding) 6rem;
}

.page-content h1 {
  font-size: 2.8rem;
  font-weight: 400;
  letter-spacing: -0.02em;
  margin-bottom: 2.5rem;
}

.page-content h2 {
  font-size: 1.8rem;
  font-weight: 400;
  margin-top: 3rem;
  margin-bottom: 1.5rem;
}

.page-content p {
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 0.4rem;
}

.page-content .paper {
  margin-top: 1.8rem;
}

.page-content .paper-title {
  margin-top: 0;
  margin-bottom: 0.2rem;
}

.page-content .paper-title a {
  color: var(--brown-light);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-content .paper-title a:hover {
  opacity: 0.6;
}

.page-content .paper-authors {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 0.1rem;
}

.page-content .paper-authors a {
  color: var(--brown-light);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-content .paper-authors a:hover {
  opacity: 0.6;
}

.page-content .paper-detail {
  color: var(--text-secondary);
}

.page-content .paper-detail a {
  color: var(--brown-light);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-content .paper-detail a:hover {
  opacity: 0.6;
}

.abstract-toggle {
  background: none;
  border: none;
  padding: 0;
  font-family: var(--font-main);
  font-size: 0.9rem;
  color: var(--text-secondary);
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 3px;
  margin-top: 0.2rem;
}

.abstract-toggle:hover {
  opacity: 0.6;
}

.abstract-content {
  display: none;
  margin-top: 0.6rem;
  padding-left: 1rem;
  border-left: 2px solid var(--border-color);
  font-size: 0.92rem;
  line-height: 1.65;
  color: var(--text-secondary);
}

.abstract-content.open {
  display: block;
}

.page-content .journal {
  font-style: italic;
}

.contact-link {
  display: block;
  font-size: 1rem;
  margin-bottom: 1.5rem;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.contact-link:hover {
  opacity: 0.6;
}

/* ─── Footer ─── */
.footer {
  padding: 3rem var(--side-padding);
  background: var(--brown);
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.85rem;
}

.footer.home-footer {
  background: var(--brown);
}

/* ─── Responsive ─── */
@media (max-width: 768px) {
  :root {
    --side-padding: 6vw;
  }

  /* Navbar */
  .navbar {
    padding: 0.85rem var(--side-padding);
    background: var(--bg-home);
    border-bottom: 1px solid var(--border-color);
  }

  .navbar.page-nav {
    background: var(--bg-page);
  }

  .navbar .site-name {
    font-size: 0.9rem;
    white-space: nowrap;
    max-width: 45%;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .navbar nav {
    gap: 1rem;
  }

  .navbar nav a {
    font-size: 0.82rem;
    white-space: nowrap;
  }

  /* Homepage */
  .home-content {
    grid-template-columns: 1fr;
    min-height: 0;
    padding-top: 5rem;
    padding-bottom: 4rem;
    gap: 1.5rem;
    align-items: start;
    text-align: center;
  }

  .home-left {
    padding-top: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
  }

  .home-left h1 {
    font-size: 1.85rem;
    margin-bottom: 1rem;
    line-height: 1.2;
  }

  .home-left .bio {
    font-size: 0.95rem;
    line-height: 1.65;
    margin-bottom: 1.75rem;
    max-width: 100%;
    text-align: left;
  }

  .home-left .bio p + p {
    margin-top: 0.7rem;
  }

  .nav-links {
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1.5rem 1.75rem;
  }

  .nav-links a {
    font-size: 0.95rem;
  }

  .home-right {
    padding-top: 0.5rem;
    order: -1;
  }

  .home-right img {
    max-width: 200px;
    border-radius: 4px;
  }

  /* Inner pages */
  .inner-page {
    padding-top: 4rem;
  }

  .page-hero {
    height: 200px;
    padding: 1.5rem var(--side-padding);
  }

  .page-hero h1 {
    font-size: 1.9rem;
  }

  .page-content {
    padding: 2rem var(--side-padding) 4rem;
  }

  .page-content h1 {
    font-size: 1.9rem;
    margin-bottom: 1.75rem;
  }

  .page-content h2 {
    font-size: 1.4rem;
    margin-top: 2.25rem;
    margin-bottom: 1.1rem;
  }

  .page-content p {
    font-size: 0.98rem;
  }

  .page-content .paper {
    margin-top: 1.5rem;
  }

  .page-content .paper-authors {
    font-size: 0.9rem;
  }

  .abstract-content {
    font-size: 0.9rem;
    padding-left: 0.85rem;
  }

  /* Footer */
  .footer {
    padding: 2rem var(--side-padding);
    font-size: 0.8rem;
  }
}

@media (max-width: 420px) {
  :root {
    --side-padding: 4vw;
  }

  .navbar {
    padding: 0.75rem var(--side-padding);
  }

  .navbar .site-name {
    font-size: 0.8rem;
    max-width: 42%;
  }

  .navbar nav {
    gap: 0.75rem;
  }

  .navbar nav a {
    font-size: 0.75rem;
  }

  .home-left h1 {
    font-size: 1.65rem;
  }

  .home-left .bio {
    font-size: 0.9rem;
  }

  .nav-links {
    gap: 1.2rem 1.4rem;
  }

  .nav-links a {
    font-size: 0.9rem;
  }

  .home-right img {
    max-width: 170px;
  }

  .page-hero {
    height: 170px;
  }

  .page-hero h1 {
    font-size: 1.65rem;
  }

  .page-content h1 {
    font-size: 1.7rem;
  }

  .page-content h2 {
    font-size: 1.25rem;
  }
}