:root {
  --color-text: #1a1a1a;
  --color-text-secondary: #555;
  --color-text-muted: #888;
  --color-bg: #fafafa;
  --color-bg-card: #fff;
  --color-accent: #2563eb;
  --color-accent-hover: #1d4ed8;
  --color-border: #e5e5e5;
  --color-header-bg: rgba(250, 250, 250, 0.9);
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --max-width: 680px;
  --radius: 8px;
}

html[data-theme="dark"] {
  --color-text: #f4f4f5;
  --color-text-secondary: #c8c8cc;
  --color-text-muted: #8f9099;
  --color-bg: #101113;
  --color-bg-card: #181a1f;
  --color-accent: #7aa2ff;
  --color-accent-hover: #a8c0ff;
  --color-border: #2b2e36;
  --color-header-bg: rgba(16, 17, 19, 0.88);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

html[data-theme="dark"] {
  color-scheme: dark;
}

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

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

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-header-bg);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  padding: 1rem 0;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
}

.site-title:hover {
  color: var(--color-accent);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.site-nav a {
  font-size: 0.9rem;
  font-weight: 450;
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color 0.2s;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--color-text);
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  color: var(--color-text-secondary);
  background: var(--color-bg-card);
  cursor: pointer;
  transition: border-color 0.2s, color 0.2s, background-color 0.2s;
}

.theme-toggle:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

.theme-toggle__icon {
  font-size: 0.95rem;
  line-height: 1;
}

/* Main content */
.site-content {
  padding: 3rem 0 4rem;
  min-height: calc(100vh - 200px);
}

/* About / Home page */
.about-header {
  display: flex;
  align-items: center;
  gap: 2rem;
  margin-bottom: 2.5rem;
}

.about-avatar {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
}

.about-intro h1 {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 0.3rem;
  line-height: 1.2;
}

.about-intro .tagline {
  font-size: 1.05rem;
  color: var(--color-text-secondary);
}

.about-body p {
  margin-bottom: 1.2rem;
  color: var(--color-text);
}

.about-body a {
  color: var(--color-accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}

.about-body a:hover {
  border-bottom-color: var(--color-accent);
}

.about-links {
  display: flex;
  gap: 1.2rem;
  margin-top: 1.5rem;
  flex-wrap: wrap;
}

.about-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  text-decoration: none;
  padding: 0.4rem 0.8rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: all 0.2s;
}

.about-links a:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

/* Section headings */
.section-title {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  margin-top: 3rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--color-border);
}

/* Experience & Education lists */
.experience-item {
  margin-bottom: 1.5rem;
  padding-left: 1rem;
  border-left: 2px solid var(--color-border);
}

.experience-item h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.15rem;
}

.experience-item .meta {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: 0.4rem;
}

.experience-item p,
.experience-item ul {
  font-size: 0.92rem;
  color: var(--color-text-secondary);
}

.experience-item ul {
  padding-left: 1.2rem;
  margin-top: 0.4rem;
}

.experience-item ul li {
  margin-bottom: 0.25rem;
}

/* Publications */
.pub-item {
  margin-bottom: 1.8rem;
}

.pub-item h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.3rem;
  line-height: 1.4;
}

.pub-item .pub-venue {
  font-size: 0.88rem;
  color: var(--color-accent);
  font-style: italic;
  margin-bottom: 0.2rem;
}

.pub-item .pub-authors {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: 0.3rem;
}

.pub-item .pub-links a {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  text-decoration: none;
  padding: 0.2rem 0.6rem;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  transition: all 0.2s;
  margin-right: 0.5rem;
}

.pub-item .pub-links a:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

/* Projects */
.project-item {
  margin-bottom: 1.8rem;
  padding: 1.2rem;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: border-color 0.2s;
}

.project-item:hover {
  border-color: var(--color-accent);
}

.project-item h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
}

.project-item h3 a {
  color: var(--color-text);
  text-decoration: none;
}

.project-item h3 a:hover {
  color: var(--color-accent);
}

.project-item p {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-bottom: 0;
}

.project-item .badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 500;
  padding: 0.15rem 0.5rem;
  background: #dbeafe;
  color: var(--color-accent);
  border-radius: 4px;
  margin-bottom: 0.5rem;
}

/* News / Blog */
.news-list {
  list-style: none;
}

.news-item {
  display: flex;
  gap: 1.2rem;
  align-items: baseline;
  padding: 1rem 0;
  border-bottom: 1px solid var(--color-border);
}

.news-item:last-child {
  border-bottom: none;
}

.news-item time {
  font-size: 0.82rem;
  color: var(--color-text-muted);
  flex-shrink: 0;
  min-width: 100px;
  font-variant-numeric: tabular-nums;
}

.news-item a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text);
  text-decoration: none;
  transition: color 0.2s;
}

.news-item a:hover {
  color: var(--color-accent);
}

.news-item p {
  font-size: 0.95rem;
  color: var(--color-text);
}

/* Post content */
.post-content {
  max-width: var(--max-width);
}

.post-header {
  margin-bottom: 2rem;
}

.post-header h1 {
  font-size: 1.8rem;
  font-weight: 700;
  margin-top: 0.5rem;
  line-height: 1.3;
}

.post-date {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.post-content p {
  margin-bottom: 1.3rem;
}

.post-content a {
  color: var(--color-accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.post-content a:hover {
  border-bottom-color: var(--color-accent);
}

.post-content h2 {
  font-size: 1.4rem;
  font-weight: 600;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
}

.post-content h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-top: 2rem;
  margin-bottom: 0.8rem;
}

.post-content ul,
.post-content ol {
  padding-left: 1.5rem;
  margin-bottom: 1.3rem;
}

.post-content li {
  margin-bottom: 0.4rem;
}

.post-content code {
  font-size: 0.88rem;
  background: #f1f5f9;
  padding: 0.15rem 0.4rem;
  border-radius: 3px;
}

.post-content pre {
  background: #1e293b;
  color: #e2e8f0;
  padding: 1.2rem;
  border-radius: var(--radius);
  overflow-x: auto;
  margin-bottom: 1.5rem;
}

.post-content pre code {
  background: none;
  padding: 0;
  color: inherit;
}

/* Page content */
.page-content h1 {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
}

.page-content a {
  color: var(--color-accent);
  text-decoration: none;
}

.page-content a:hover {
  text-decoration: underline;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 2rem 0;
  text-align: center;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

.footer-links a {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color 0.2s;
}

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

.footer-copy {
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

/* Responsive */
@media (max-width: 600px) {
  .about-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }

  .about-avatar {
    width: 90px;
    height: 90px;
  }

  .about-intro h1 {
    font-size: 1.5rem;
  }

  .news-item {
    flex-direction: column;
    gap: 0.3rem;
  }

  .site-nav {
    gap: 0.8rem;
  }

  .site-nav a {
    font-size: 0.85rem;
  }
}