:root {
  --bg: #ffffff;
  --text: #111111;
  --muted: #666666;
  --border: #e5e5e5;
  --accent: #000000;
}

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
}

/* Navigation */
.top-nav {
  border-bottom: 1px solid var(--border);
  background: #fafafa;
}

.nav-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-brand {
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--accent);
  text-decoration: none;
}

.nav-links a {
  margin-left: 18px;
  color: var(--text);
  text-decoration: none;
  font-size: 0.95rem;
}

.nav-links a:hover {
  text-decoration: underline;
}

/* Layout */
.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 40px 20px 60px;
}

/* Home */
.hero {
  padding: 60px 0 40px;
}

.hero h1 {
  font-size: 2.4rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

.subtitle {
  font-size: 1.2rem;
  color: var(--muted);
}

/* About */
.about-section h1 {
  font-size: 2rem;
  margin-bottom: 20px;
}

.bio-text {
  font-size: 1.05rem;
  max-width: 720px;
  margin-bottom: 40px;
  color: #222;
}

/* Education grid */
.education-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.edu-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  background: #fafafa;
}

.edu-logo {
  width: 80px;
  height: 80px;
  object-fit: contain;
  display: block;
  margin-bottom: 14px;
}

.edu-card h2 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.degree {
  font-weight: 500;
  margin-bottom: 4px;
}

.edu-detail {
  font-size: 0.92rem;
  color: var(--muted);
}

/* Footer */
.footer {
  border-top: 1px solid var(--border);
  margin-top: 60px;
  padding: 20px;
  text-align: center;
  color: var(--muted);
  font-size: 0.9rem;
}

/* Mobile tweaks */
@media (max-width: 600px) {
  .hero h1 {
    font-size: 1.8rem;
  }

  .subtitle {
    font-size: 1rem;
  }

  .about-section h1 {
    font-size: 1.6rem;
  }
}