/* ===== Reset & Base ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg: #0d1117;
  --bg-alt: #10151c;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --accent: #58a6ff;
  --accent-hover: #79b8ff;
  --border: #21262d;
  --font-main: 'Inter', sans-serif;
  --font-code: 'Fira Code', monospace;
}

body {
  font-family: var(--font-main);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  scroll-behavior: smooth;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

a {
  text-decoration: none;
  color: inherit;
}

ul {
  list-style: none;
}

/* ===== Navbar ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(13, 17, 23, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.nav-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  font-weight: 700;
  font-size: 1.3rem;
}

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

.nav-links {
  display: flex;
  gap: 32px;
}

.nav-links a {
  font-weight: 500;
  color: var(--text-muted);
  transition: color 0.2s;
}

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

.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  font-size: 1.5rem;
  cursor: pointer;
}

/* ===== Hero ===== */
.hero {
  min-height: 90vh;
  display: flex;
  align-items: center;
  background: radial-gradient(circle at top right, #161b22, var(--bg));
}

.eyebrow {
  color: var(--accent);
  font-family: var(--font-code);
  margin-bottom: 8px;
}

.hero h1 {
  font-size: 3.5rem;
  font-weight: 700;
}

.subtitle {
  font-size: 1.4rem;
  color: var(--text-muted);
  font-weight: 500;
  margin: 8px 0 20px;
}

.hero-text {
  max-width: 560px;
  color: var(--text-muted);
  margin-bottom: 32px;
}

.hero-buttons {
  display: flex;
  gap: 16px;
}

.btn {
  padding: 12px 24px;
  border-radius: 6px;
  font-weight: 600;
  transition: all 0.2s;
  display: inline-block;
}

.btn-primary {
  background: var(--accent);
  color: #0d1117;
}

.btn-primary:hover {
  background: var(--accent-hover);
}

.btn-outline {
  border: 1px solid var(--border);
  color: var(--text);
}

.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ===== Sections ===== */
.section {
  padding: 100px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-title {
  font-size: 2.2rem;
  margin-bottom: 12px;
  text-align: center;
}

.section-subtitle {
  text-align: center;
  color: var(--text-muted);
  margin-bottom: 48px;
}

/* ===== About ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 48px;
  align-items: start;
}

.about-text p {
  margin-bottom: 16px;
  color: var(--text-muted);
}

.about-facts li {
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
  color: var(--text-muted);
}

.about-facts strong {
  color: var(--text);
}

/* ===== Topics ===== */
.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.topic-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 24px;
  transition: transform 0.2s, border-color 0.2s;
}

.topic-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
}

.topic-card h3 {
  margin-bottom: 10px;
  color: var(--accent);
}

.topic-card p {
  color: var(--text-muted);
  margin-bottom: 14px;
  font-size: 0.95rem;
}

.topic-card pre {
  background: #161b22;
  padding: 12px;
  border-radius: 6px;
  overflow-x: auto;
}

.topic-card code {
  font-family: var(--font-code);
  font-size: 0.85rem;
  color: #a5d6ff;
}

/* ===== Contact ===== */
.contact-content {
  text-align: center;
}

.contact-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
}

.contact-link {
  padding: 14px 24px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-weight: 500;
  transition: all 0.2s;
}

.contact-link:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ===== Footer ===== */
.footer {
  padding: 24px 0;
  text-align: center;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
  font-size: 0.9rem;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav-links {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--bg);
    flex-direction: column;
    padding: 20px;
    border-bottom: 1px solid var(--border);
    display: none;
  }

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

  .menu-toggle {
    display: block;
  }

  .hero h1 {
    font-size: 2.5rem;
  }

  .about-grid {
    grid-template-columns: 1fr;
  }
}