:root {
  --navy: #0f2a5f;
  --teal: #2a9d8f;
  --teal-strong: #1f7a6f;
  --bg: #f7f8fa;
  --surface: #ffffff;
  --text: #1c2333;
  --muted: #5b6475;
  --border: #dfe3ea;
  --radius: 10px;
  --max: 960px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --navy: #9db8ff;
    --teal: #4cc2b3;
    --teal-strong: #6fd6c8;
    --bg: #0f141c;
    --surface: #171e29;
    --text: #e6e9ef;
    --muted: #a0a8b8;
    --border: #2a3342;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}

a { color: var(--teal-strong); }
a:hover { color: var(--navy); }

.wrap {
  max-width: var(--max);
  margin: 0 auto;
  padding-inline: 1.25rem;
}

/* Header / nav */
.site-header {
  background: var(--surface);
  border-bottom: 3px solid var(--teal);
}
.site-header .wrap {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding-block: 0.9rem;
}
.brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--navy);
  text-decoration: none;
}
.site-nav { display: flex; flex-wrap: wrap; gap: 1.25rem; }
.site-nav a { color: var(--text); text-decoration: none; font-weight: 500; }
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--teal-strong); }

main { padding-block: 2.5rem 3rem; }

h1, h2, h3 { color: var(--navy); line-height: 1.25; }
h1 { font-size: clamp(1.8rem, 4vw, 2.5rem); margin: 0 0 0.5rem; }
h2 {
  font-size: 1.4rem;
  margin: 2.5rem 0 1rem;
  padding-bottom: 0.35rem;
  border-bottom: 2px solid var(--border);
}
h3 { font-size: 1.1rem; margin: 1.5rem 0 0.5rem; }

.lead { font-size: 1.15rem; color: var(--muted); }

/* Buttons */
.btn-row { display: flex; flex-wrap: wrap; gap: 0.75rem; margin-top: 1.25rem; }
.btn {
  display: inline-block;
  padding: 0.6rem 1.1rem;
  border-radius: var(--radius);
  border: 2px solid var(--teal);
  background: var(--teal);
  color: #fff;
  font-weight: 600;
  text-decoration: none;
}
.btn:hover { background: var(--teal-strong); border-color: var(--teal-strong); color: #fff; }
.btn.secondary { background: transparent; color: var(--teal-strong); }
.btn.secondary:hover { background: var(--teal); color: #fff; }

/* Project cards */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.25rem;
}
.card {
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  text-decoration: none;
  color: var(--text);
  transition: border-color 0.15s, transform 0.15s;
}
a.card:hover { border-color: var(--teal); transform: translateY(-2px); color: var(--text); }
.card h3 { margin-top: 0; }
.card p { margin: 0 0 1rem; color: var(--muted); flex: 1; }
.card .more { font-weight: 600; color: var(--teal-strong); }
.card.placeholder { border-style: dashed; opacity: 0.75; }

.tags { display: flex; flex-wrap: wrap; gap: 0.4rem; margin: 0 0 1rem; padding: 0; list-style: none; }
.tags li {
  font-size: 0.8rem;
  padding: 0.15rem 0.55rem;
  border-radius: 999px;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--muted);
}

/* Resume */
.resume ul { padding-left: 1.2rem; }
.resume li { margin-bottom: 0.35rem; }
.role { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 0.25rem 1rem; }
.role .when { color: var(--muted); }

/* PDF viewer */
.pdf-frame {
  width: 100%;
  height: 80vh;
  min-height: 500px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
}

.breadcrumb { font-size: 0.9rem; color: var(--muted); margin-bottom: 1rem; }

.site-footer {
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9rem;
}
.site-footer .wrap { padding-block: 1.5rem; }

@media (max-width: 600px) {
  .pdf-frame { height: 60vh; min-height: 360px; }
}