@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600&display=swap');

:root {
  --bg: #ffffff;
  --text: #0a0a0a;
  --text-secondary: #374151;
  --text-muted: #6b7280;
  --border: #e5e7eb;
  --accent: #0a0a0a;
}

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

html {
  font-size: 16px;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

/* Nav */
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 900px;
  margin: 0 auto;
  padding: 1.5rem 2rem;
  border-bottom: 1px solid var(--border);
}

.nav-logo {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.01em;
}

.nav-email {
  font-size: 0.8125rem;
  color: var(--text-muted);
  text-decoration: none;
}

.nav-email:hover {
  color: var(--text);
}

/* Main layout */
.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* Hero */
.hero {
  padding: 5rem 0 4rem;
  max-width: 640px;
}

.hero-label {
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

.hero h1 {
  font-size: 2.25rem;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.03em;
  color: var(--text);
  margin-bottom: 1.5rem;
}

.hero-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 520px;
}

/* Sections */
.section {
  padding: 3.5rem 0;
  border-top: 1px solid var(--border);
}

.section-label {
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

/* Two-column layout for research section */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
}

.col-heading {
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--text);
  margin-bottom: 0.75rem;
}

.col-text {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* Post list */
.post-list {
  display: flex;
  flex-direction: column;
}

.post-item {
  display: flex;
  align-items: baseline;
  gap: 1.5rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--border);
  text-decoration: none;
  transition: opacity 0.15s;
}

.post-item:first-child {
  border-top: 1px solid var(--border);
}

.post-item:hover {
  opacity: 0.6;
}

.post-date {
  font-size: 0.8125rem;
  color: var(--text-muted);
  flex-shrink: 0;
  font-variant-numeric: tabular-nums;
}

.post-title {
  font-size: 0.9375rem;
  color: var(--text);
  font-weight: 500;
}

/* Contact */
.contact-links {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.contact-link {
  font-size: 0.875rem;
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
}

.contact-link:hover {
  color: var(--text);
}

.contact-link.primary {
  color: var(--text);
  font-weight: 600;
}

/* Footer */
.footer {
  padding: 2rem 0;
  border-top: 1px solid var(--border);
  font-size: 0.8125rem;
  color: var(--text-muted);
}

/* Blog post page */
.post-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 900px;
  margin: 0 auto;
  padding: 1.5rem 2rem;
  border-bottom: 1px solid var(--border);
}

.back-link {
  font-size: 0.8125rem;
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 500;
}

.back-link:hover {
  color: var(--text);
}

.post-container {
  max-width: 680px;
  margin: 0 auto;
  padding: 0 2rem;
}

.post-header {
  padding: 3.5rem 0 2.5rem;
}

.post-header h1 {
  font-size: 1.75rem;
  font-weight: 600;
  letter-spacing: -0.025em;
  line-height: 1.25;
  margin-bottom: 0.75rem;
}

.post-meta {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.post-body {
  font-size: 1rem;
  color: var(--text-secondary);
  padding-bottom: 4rem;
}

.post-body p {
  margin-bottom: 1.25rem;
  line-height: 1.75;
}

.post-body h2 {
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -0.01em;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
}

.post-body ul,
.post-body ol {
  margin-bottom: 1.25rem;
  padding-left: 1.5rem;
}

.post-body li {
  margin-bottom: 0.5rem;
  line-height: 1.75;
}

.post-body a {
  color: var(--text);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--border);
}

.post-body a:hover {
  text-decoration-color: var(--text);
}

.post-body code {
  background: #f3f4f6;
  padding: 0.15rem 0.4rem;
  border-radius: 3px;
  font-size: 0.875em;
  font-family: 'SF Mono', 'Fira Code', monospace;
}

.post-body blockquote {
  border-left: 3px solid var(--border);
  padding-left: 1.25rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

/* Responsive */
@media (max-width: 640px) {
  .nav, .post-nav {
    padding: 1.25rem 1.25rem;
  }

  .container {
    padding: 0 1.25rem;
  }

  .post-container {
    padding: 0 1.25rem;
  }

  .hero {
    padding: 3rem 0 2.5rem;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .two-col {
    grid-template-columns: 1fr;
    gap: 1.75rem;
  }

  .post-item {
    flex-direction: column;
    gap: 0.25rem;
  }

  .contact-links {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
  }
}

::selection {
  background: var(--text);
  color: var(--bg);
}