:root {
  --bg: #ffffff;
  --bg-alt: #f5f7fa;
  --text: #1c2530;
  --muted: #5a6b7d;
  --accent: #1f5fae;
  --border: #e2e8f0;
  --maxw: 880px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px;
}

.site-header {
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--border);
  z-index: 10;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 58px;
}

.brand {
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  font-size: 17px;
}

.site-header nav a {
  color: var(--muted);
  text-decoration: none;
  margin-left: 18px;
  font-size: 14px;
}

.site-header nav a:hover { color: var(--accent); }

.hero {
  padding: 72px 0 48px;
  border-bottom: 1px solid var(--border);
}

.hero h1 {
  font-size: 40px;
  margin: 0 0 10px;
}

.lead {
  font-size: 20px;
  margin: 0 0 6px;
  color: var(--text);
}

.sub {
  font-size: 16px;
  color: var(--muted);
  margin: 0 0 24px;
}

.actions { display: flex; gap: 12px; flex-wrap: wrap; }

.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  padding: 10px 18px;
  border-radius: 8px;
  text-decoration: none;
  font-size: 15px;
  border: 1px solid var(--accent);
}

.btn-ghost {
  background: transparent;
  color: var(--accent);
}

.section { padding: 48px 0; }
.section.alt { background: var(--bg-alt); }

.section h2 {
  font-size: 24px;
  margin: 0 0 18px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px;
}

.card h3 { margin: 0 0 6px; font-size: 17px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }

.project {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
  background: #fff;
}

.project h3 { margin: 0 0 4px; font-size: 19px; }

.tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  color: var(--accent);
  background: #eaf1fb;
  border: 1px solid #cdddf5;
  border-radius: 20px;
  padding: 2px 10px;
  margin: 0 0 10px;
}

.stack {
  font-size: 13px;
  color: var(--muted);
  margin: 12px 0 0;
}

.muted { color: var(--muted); font-size: 14px; }

.links {
  list-style: none;
  padding: 0;
  margin: 0;
}

.links li { margin: 6px 0; }
.links a { color: var(--accent); text-decoration: none; }
.links a:hover { text-decoration: underline; }

.site-footer {
  border-top: 1px solid var(--border);
  padding: 24px 0;
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 600px) {
  .grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 32px; }
}