:root {
  --radius: 14px;
  --max-width: 780px;
}

html[data-theme="dark"] {
  --bg: #0f1115;
  --bg-alt: #171a21;
  --text: #f2f3f5;
  --text-muted: #9aa0ab;
  --accent: #6c8cff;
  --accent-soft: rgba(108, 140, 255, 0.12);
  --border: #262a33;
}

html[data-theme="light"] {
  --bg: #ffffff;
  --bg-alt: #f5f6f8;
  --text: #14161a;
  --text-muted: #5b6270;
  --accent: #3355dd;
  --accent-soft: rgba(51, 85, 221, 0.08);
  --border: #e4e6eb;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  transition: background 0.2s ease, color 0.2s ease;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.hero {
  padding: 6rem 0 4rem;
  text-align: center;
  background: radial-gradient(ellipse at top, var(--bg-alt), var(--bg));
  border-bottom: 1px solid var(--border);
}

.eyebrow {
  color: var(--accent);
  font-weight: 600;
  font-size: 0.9rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
}

.hero-tagline {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 500px;
  margin: 0 auto 2rem;
}

.hero-links {
  display: flex;
  gap: 0.85rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 0.7rem 1.4rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: transform 0.15s ease, opacity 0.15s ease;
}
.btn:hover { transform: translateY(-2px); }

.btn-primary { background: var(--accent); color: #0f1115; }
.btn-secondary { background: transparent; color: var(--text); border: 1px solid var(--border); }

.site-nav {
  position: sticky;
  top: 0;
  background: rgba(15, 17, 21, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  z-index: 10;
}
.nav-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 1.5rem;
}
.nav-links { display: flex; gap: 1.5rem; }
.nav-links a { color: var(--text-muted); text-decoration: none; font-weight: 500; font-size: 0.9rem; }
.nav-links a:hover { color: var(--text); }

#theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg-alt);
  color: var(--text);
  cursor: pointer;
  transition: border-color 0.15s ease;
}
#theme-toggle:hover { border-color: var(--accent); }
.icon-moon { display: none; }
html[data-theme="dark"] .icon-sun { display: none; }
html[data-theme="dark"] .icon-moon { display: block; }

main { padding: 4rem 0; }
section { margin-bottom: 4.5rem; }
section h2 { font-size: 1.5rem; font-weight: 700; margin-bottom: 1.25rem; letter-spacing: -0.01em; }
section p { color: var(--text-muted); }

.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
}
.project-card {
  display: block;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem;
  text-decoration: none;
  color: var(--text);
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.project-card:hover { border-color: var(--accent); transform: translateY(-3px); }
.project-card h3 { font-size: 1.05rem; margin-bottom: 0.5rem; }
.project-card p { font-size: 0.9rem; margin-bottom: 1rem; }

.tags { display: flex; gap: 0.4rem; flex-wrap: wrap; }
.tag {
  font-size: 0.75rem;
  background: var(--accent-soft);
  color: var(--accent);
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  font-weight: 600;
}

.contact-links { display: flex; gap: 1.2rem; flex-wrap: wrap; margin-top: 0.75rem; }
.contact-links a { color: var(--accent); text-decoration: none; font-weight: 500; }
.contact-links a:hover { text-decoration: underline; }

footer { border-top: 1px solid var(--border); padding: 2rem 0; text-align: center; }
footer p { color: var(--text-muted); font-size: 0.85rem; }