:root {
  --bg: #ffffff;
  --text: #1a1a1a;
  --muted: #6b6b6b;
  --line: #e6e6e6;
  --accent: #1f5fbf;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111213;
    --text: #e8e8e8;
    --muted: #9a9a9a;
    --line: #2a2b2d;
    --accent: #7aa7ff;
  }
}

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

body {
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

main {
  max-width: 680px;
  margin: 0 auto;
  padding: 64px 20px 48px;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

h1 { font-size: 2rem; font-weight: 600; letter-spacing: -0.02em; }
h2 {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin-bottom: 16px;
}
h3 { font-size: 1rem; font-weight: 600; }

.tagline { color: var(--muted); margin: 8px 0 16px; }

nav { display: flex; flex-wrap: wrap; gap: 16px; }

section {
  border-top: 1px solid var(--line);
  padding-top: 24px;
  margin-top: 40px;
}

.certs { list-style: none; display: grid; gap: 12px; }
.certs a {
  display: flex;
  align-items: center;
  gap: 14px;
  color: var(--text);
}
.certs a:hover strong { color: var(--accent); }
.certs img { flex-shrink: 0; }
.certs span { display: flex; flex-direction: column; }
.certs small { color: var(--muted); font-size: 0.85rem; }

article + article { margin-top: 20px; }
article p { margin-top: 4px; }
.tags { color: var(--muted); font-size: 0.85rem; }

.skills { display: grid; grid-template-columns: 120px 1fr; gap: 8px 16px; }
.skills dt { font-weight: 600; }

@media (max-width: 520px) {
  .skills { grid-template-columns: 1fr; gap: 0; }
  .skills dd { margin-bottom: 10px; }
}

footer {
  margin-top: 56px;
  color: var(--muted);
  font-size: 0.85rem;
}

.avatar {
  width: 96px;
  height: 96px;
  border-radius: 50%;
  object-fit: cover;
  margin-bottom: 16px;
}

.orgs { list-style: none; display: grid; gap: 12px; }
.orgs li { display: flex; flex-direction: column; }
.orgs small { color: var(--muted); font-size: 0.85rem; }