:root {
  --color-bg: #0f1117;
  --color-surface: #171a23;
  --color-text: #e7e9ee;
  --color-text-muted: #9aa0ac;
  --color-accent: #6ea8fe;
  --max-width: 960px;
  --radius: 10px;
}

* {
  box-sizing: border-box;
}

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

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

a {
  color: var(--color-accent);
}

/* Header / Nav */

.site-header {
  position: sticky;
  top: 0;
  background: rgba(15, 17, 23, 0.9);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid #262a35;
  z-index: 10;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.5rem;
}

.logo {
  font-weight: 700;
  text-decoration: none;
  color: var(--color-text);
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 1.5rem;
  margin: 0;
  padding: 0;
}

.nav-links a {
  text-decoration: none;
  color: var(--color-text-muted);
}

.nav-links a:hover {
  color: var(--color-text);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--color-text);
}

/* Hero */

.hero {
  padding: 6rem 1.5rem 4rem;
  text-align: center;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  margin-bottom: 0.5rem;
}

.hero-subtitle {
  color: var(--color-text-muted);
  font-size: 1.15rem;
  max-width: 40ch;
  margin: 0 auto 2rem;
}

.btn {
  display: inline-block;
  background: var(--color-accent);
  color: #0f1117;
  font-weight: 600;
  text-decoration: none;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
}

/* Sections */

.section {
  padding: 4rem 1.5rem;
  border-top: 1px solid #262a35;
}

.section h2 {
  font-size: 1.75rem;
  margin-bottom: 1.5rem;
}

/* Projects */

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}

.project-card {
  background: var(--color-surface);
  border: 1px solid #262a35;
  border-radius: var(--radius);
  padding: 1.5rem;
}

.project-card h3 {
  margin-top: 0;
}

.project-link {
  text-decoration: none;
  font-weight: 600;
}

/* Footer */

.site-footer {
  text-align: center;
  padding: 2rem 1.5rem;
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

/* Mobile nav */

@media (max-width: 640px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--color-surface);
    border-bottom: 1px solid #262a35;
    padding: 1rem 1.5rem;
    display: none;
  }

  .nav-links.open {
    display: flex;
  }
}