/* Notion-style academic theme — shared across all pages */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-font-smoothing: antialiased; }
body {
  font-family: 'Inter', 'Noto Serif SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background-color: #faf9f7;
  color: rgba(0,0,0,0.9);
  line-height: 1.6;
  min-height: 100vh;
}
a { color: #0075de; text-decoration: none; }
a:hover { text-decoration: underline; }

/* Top Nav */
.top-nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(250,249,247,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0,0,0,0.06);
}
.top-nav-inner {
  max-width: 860px; margin: 0 auto;
  display: flex; align-items: center;
  justify-content: space-between;
  height: 52px; padding: 0 1.5rem;
}
.top-nav-name { font-size: 0.85rem; font-weight: 500; color: rgba(0,0,0,0.6); }
.top-nav-links { display: flex; align-items: center; gap: 1.5rem; list-style: none; }
.top-nav-links a {
  font-size: 0.8rem; color: rgba(0,0,0,0.5);
  text-decoration: none; transition: color 0.15s;
  font-weight: 450;
}
.top-nav-links a:hover { color: #0075de; }
.top-nav-links a.active { color: rgba(0,0,0,0.8); font-weight: 500; }

/* Container */
.page { max-width: 860px; margin: 0 auto; padding: 2.5rem 1.5rem 5rem; }

/* Headings */
h1 { font-size: 2rem; font-weight: 600; line-height: 1.3; letter-spacing: -0.015em; color: rgba(0,0,0,0.92); margin-bottom: 1.5rem; }
h2 { font-size: 1.3rem; font-weight: 600; line-height: 1.3; letter-spacing: -0.01em; color: rgba(0,0,0,0.88); margin-bottom: 1rem; margin-top: 2rem; }
h2:first-child { margin-top: 0; }
h3 { font-size: 1.05rem; font-weight: 600; color: rgba(0,0,0,0.85); margin-bottom: 0.5rem; }

/* Cards */
.card {
  background: #fff;
  border: 1px solid rgba(0,0,0,0.07);
  border-radius: 12px;
  padding: 1.25rem 1.5rem;
  box-shadow: rgba(0,0,0,0.04) 0px 4px 18px, rgba(0,0,0,0.027) 0px 2.025px 7.84688px, rgba(0,0,0,0.02) 0px 0.8px 2.925px, rgba(0,0,0,0.01) 0px 0.175px 1.04062px;
}
.card + .card { margin-top: 0.75rem; }

/* Section labels */
.section-label {
  font-size: 0.75rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.06em; color: rgba(0,0,0,0.35);
  margin-bottom: 0.75rem;
}

/* Tags */
.tag {
  display: inline-block;
  font-size: 0.7rem; font-weight: 500;
  padding: 2px 10px; border-radius: 9999px;
  background: #f2f9ff; color: #097fe8;
}

/* Divider */
hr { border: none; border-top: 1px solid rgba(0,0,0,0.06); margin: 2rem 0; }

/* Grid */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.grid-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 1rem; }

/* Lists */
ul { padding-left: 1.2rem; color: rgba(0,0,0,0.75); font-size: 0.9rem; line-height: 1.7; }
li { margin-bottom: 0.3rem; }

/* Muted text */
.muted { color: rgba(0,0,0,0.45); font-size: 0.8rem; }

/* Responsive */
@media (max-width: 640px) {
  .page { padding: 1.5rem 1rem 3rem; }
  .top-nav-inner { padding: 0 1rem; }
  .top-nav-links { gap: 0.8rem; }
  .top-nav-links a { font-size: 0.75rem; }
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
  h1 { font-size: 1.6rem; }
}