/* ---------- Base Reset ---------- */
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  line-height: 1.6;
  background: #0d1117;
  color: #c9d1d9;
}

/* ---------- Layout ---------- */
header, nav, main, footer { width: 100%; }
main { max-width: 1000px; margin: 0 auto; padding: 24px; }
section { margin: 48px 0; }

/* ---------- Header ---------- */
header {
  background: #161b22;
  border-bottom: 1px solid #30363d;
  padding: 32px 16px;
  text-align: center;
}
header h1 {
  font-size: clamp(1.8rem, 2.5vw + 1rem, 2.6rem);
  color: #58a6ff;
  letter-spacing: 1px;
}
header p {
  margin-top: 6px;
  color: #8b949e;
  font-size: 1rem;
}

/* ---------- Nav ---------- */
nav {
  display: flex;
  justify-content: center;
  gap: 18px;
  padding: 14px 10px;
  border-bottom: 1px solid #21262d;
  background: #0f1520;
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(6px);
}
nav a {
  text-decoration: none;
  color: #c9d1d9;
  font-weight: 600;
  padding: 6px 10px;
  border-radius: 8px;
  position: relative;
}
nav a:hover { color: #58a6ff; }
nav a::after {
  content: "";
  position: absolute;
  left: 10px; right: 10px; bottom: 1px;
  height: 2px; width: 0;
  background: #58a6ff;
  transition: width .25s ease;
}
nav a:hover::after { width: calc(100% - 20px); }

/* ---------- Headings ---------- */
h2 {
  margin-bottom: 14px;
  color: #58a6ff;
  font-size: 1.4rem;
  border-left: 4px solid #58a6ff;
  padding-left: 10px;
}
h3 { font-size: 1.05rem; color: #e6edf3; margin-bottom: 6px; }

/* ---------- Card Sections ---------- */
#about, #projects, #tools, #contact {
  background: #161b22;
  border: 1px solid #30363d;
  border-radius: 12px;
  padding: 18px;
  box-shadow: 0 6px 18px rgba(0,0,0,.25);
}

/* ---------- Projects list ---------- */
#projects > div {
  background: #0d1117;
  border: 1px solid #2d333b;
  border-radius: 10px;
  padding: 14px;
  margin: 14px 0;
  transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
}
#projects > div:hover {
  transform: translateY(-3px);
  border-color: #58a6ff;
  box-shadow: 0 10px 24px rgba(20,80,150,.25);
}
#projects > div a {
  display: inline-block;
  margin-top: 8px;
  padding: 8px 12px;
  border-radius: 8px;
  text-decoration: none;
  background: #58a6ff;
  color: #0b1220;
  font-weight: 700;
}
#projects > div a:hover {
  background: #1f6feb;
  color: #ffffff;
  text-decoration: none;
}

/* ---------- Tools list ---------- */
#tools > div {
  background: #0d1117;
  border: 1px solid #2d333b;
  border-radius: 10px;
  padding: 14px;
  margin: 14px 0;
  transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease;
}
#tools > div:hover {
  transform: translateY(-3px);
  border-color: #58a6ff;
  box-shadow: 0 10px 24px rgba(20,80,150,.25);
}

/* ---------- Contact Section ---------- */
#contact img {
  width: 25px;
  height: 25px;
  margin-right: 10px;
  filter: drop-shadow(0 0 1.5px #58a6ff);
}
#contact a {
  color: #58a6ff;
  text-decoration: none;
  font-weight: 500;
}