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

:root {
  --color-primary: #1a1a2e;
  --color-accent: #2563eb;
  --color-accent-light: #3b82f6;
  --color-text: #1f2937;
  --color-text-secondary: #6b7280;
  --color-bg: #ffffff;
  --color-bg-alt: #f9fafb;
  --color-border: #e5e7eb;
  --color-highlight: #dbeafe;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --max-width: 860px;
  --nav-height: 60px;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 24px);
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

img {
  max-width: 100%;
  display: block;
}

/* ===== Navigation ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
}

.navbar__inner {
  width: 100%;
  max-width: var(--max-width);
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.navbar__brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-primary);
  letter-spacing: -0.02em;
}

.navbar__links {
  display: flex;
  gap: 28px;
  list-style: none;
}

.navbar__links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color 0.2s ease;
  position: relative;
}

.navbar__links a:hover,
.navbar__links a.active {
  color: var(--color-primary);
}

.navbar__links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width 0.2s ease;
}

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

/* Mobile hamburger */
.navbar__toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.navbar__toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  margin: 5px 0;
  transition: all 0.3s ease;
  border-radius: 2px;
}

/* ===== Main Content ===== */
.main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: calc(var(--nav-height) + 48px) 24px 80px;
}

/* ===== Section ===== */
.section {
  margin-bottom: 72px;
}

.section__title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 28px;
  letter-spacing: -0.02em;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-border);
}

/* ===== About / Hero ===== */
.about {
  display: flex;
  gap: 48px;
  align-items: flex-start;
  margin-bottom: 72px;
}

.about__photo-wrapper {
  flex-shrink: 0;
}

.about__photo {
  width: 180px;
  height: 180px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--color-border);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
}

.about__info {
  flex: 1;
}

.about__name {
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-primary);
  letter-spacing: -0.03em;
  line-height: 1.2;
}

.about__name-cn {
  font-weight: 400;
  font-size: 1.2rem;
  color: var(--color-text-secondary);
  margin-left: 8px;
}

.about__title {
  font-size: 1.05rem;
  color: var(--color-text-secondary);
  margin-top: 6px;
  font-weight: 400;
}

.about__affiliation {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  margin-top: 2px;
}

.about__bio {
  margin-top: 18px;
  font-size: 0.97rem;
  color: var(--color-text);
  line-height: 1.8;
}

.about__interests {
  margin-top: 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.about__tag {
  display: inline-block;
  padding: 4px 14px;
  background: var(--color-highlight);
  color: var(--color-accent);
  border-radius: 20px;
  font-size: 0.82rem;
  font-weight: 500;
}

.about__links {
  margin-top: 20px;
  display: flex;
  gap: 16px;
  align-items: center;
}

.about__links a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  padding: 6px 14px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  transition: all 0.2s ease;
}

.about__links a:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
  background: var(--color-highlight);
}

.about__links svg {
  width: 16px;
  height: 16px;
}

/* ===== News ===== */
.news__list {
  list-style: none;
}

.news__item {
  display: flex;
  gap: 20px;
  padding: 14px 0;
  border-bottom: 1px solid var(--color-border);
  align-items: baseline;
}

.news__item:last-child {
  border-bottom: none;
}

.news__date {
  flex-shrink: 0;
  width: 110px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-accent);
  font-family: var(--font-mono);
}

.news__text {
  font-size: 0.95rem;
  color: var(--color-text);
}

.news__empty {
  color: var(--color-text-secondary);
  font-style: italic;
  font-size: 0.95rem;
}

/* ===== Publications ===== */
.pub__year {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-top: 28px;
  margin-bottom: 16px;
}

.pub__year:first-child {
  margin-top: 0;
}

.pub__item {
  padding: 18px 0;
  border-bottom: 1px solid var(--color-border);
}

.pub__item:last-child {
  border-bottom: none;
}

.pub__title {
  font-weight: 700;
  font-size: 1rem;
  color: var(--color-primary);
  line-height: 1.5;
}

.pub__authors {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-top: 4px;
}

.pub__authors .me {
  font-weight: 700;
  color: var(--color-text);
}

.pub__venue {
  font-size: 0.88rem;
  color: var(--color-text-secondary);
  font-style: italic;
  margin-top: 2px;
}

.pub__actions {
  margin-top: 8px;
  display: flex;
  gap: 10px;
}

.pub__actions a {
  font-size: 0.8rem;
  font-weight: 600;
  padding: 3px 10px;
  border: 1px solid var(--color-accent);
  border-radius: 4px;
  color: var(--color-accent);
  transition: all 0.2s ease;
}

.pub__actions a:hover {
  background: var(--color-accent);
  color: #fff;
}

.pub__empty {
  color: var(--color-text-secondary);
  font-style: italic;
  font-size: 0.95rem;
  padding: 8px 0;
}

/* ===== Experience / Education ===== */
.exp__list {
  list-style: none;
}

.exp__item {
  display: flex;
  gap: 20px;
  padding: 20px 0;
  border-bottom: 1px solid var(--color-border);
  align-items: flex-start;
}

.exp__item:last-child {
  border-bottom: none;
}

.exp__period {
  flex-shrink: 0;
  width: 130px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-accent);
  font-family: var(--font-mono);
  padding-top: 2px;
}

.exp__details {
  flex: 1;
}

.exp__role {
  font-weight: 700;
  font-size: 1rem;
  color: var(--color-primary);
}

.exp__org {
  font-size: 0.92rem;
  color: var(--color-text-secondary);
  margin-top: 2px;
}

.exp__org a {
  color: var(--color-text-secondary);
  text-decoration: underline;
  text-decoration-color: var(--color-border);
  text-underline-offset: 2px;
}

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

/* ===== Contact ===== */
.contact__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.contact__card {
  padding: 24px;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  background: var(--color-bg-alt);
}

.contact__card-title {
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--color-primary);
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.contact__card-content {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.contact__card-content a {
  word-break: break-all;
}

/* ===== Footer ===== */
.footer {
  text-align: center;
  padding: 32px 24px;
  border-top: 1px solid var(--color-border);
  font-size: 0.82rem;
  color: var(--color-text-secondary);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .navbar__links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 16px 24px;
    gap: 0;
    border-bottom: 1px solid var(--color-border);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  }

  .navbar__links.open {
    display: flex;
  }

  .navbar__links li {
    padding: 10px 0;
    border-bottom: 1px solid var(--color-border);
  }

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

  .navbar__toggle {
    display: block;
  }

  .navbar__toggle.open span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }

  .navbar__toggle.open span:nth-child(2) {
    opacity: 0;
  }

  .navbar__toggle.open span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }

  .about {
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 24px;
  }

  .about__photo {
    width: 140px;
    height: 140px;
  }

  .about__interests {
    justify-content: center;
  }

  .about__links {
    justify-content: center;
    flex-wrap: wrap;
  }

  .about__name {
    font-size: 1.6rem;
  }

  .news__item {
    flex-direction: column;
    gap: 4px;
  }

  .news__date {
    width: auto;
  }

  .exp__item {
    flex-direction: column;
    gap: 4px;
  }

  .exp__period {
    width: auto;
  }

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

  .main {
    padding-top: calc(var(--nav-height) + 32px);
  }
}

@media (max-width: 480px) {
  .about__name {
    font-size: 1.4rem;
  }

  .section__title {
    font-size: 1.25rem;
  }

  .about__links a {
    padding: 5px 10px;
    font-size: 0.82rem;
  }
}