/* --- Custom Variables & Reset --- */
:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --text-main: #1a1a1a;
  --text-muted: #666666;
  --accent: #0066cc;
  --border-color: #e5e5e5;
  --font-stack:
    system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --transition-speed: 0.25s;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-stack);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
}

/* --- Navigation --- */
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem 10%;
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(5px);
  z-index: 100;
}

.navbar .logo {
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.5px;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 2rem;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-main);
  font-weight: 500;
  transition: color var(--transition-speed);
}

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

/* --- Hero Section --- */
.hero-section {
  display: flex;
  align-items: center;
  min-height: 55vh;
  padding: 0 10%;
  background-color: var(--bg-secondary);
}

.hero-content {
  max-width: 600px;
}

.hero-content h1 {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1.5rem;
  letter-spacing: -1px;
}

.hero-content .highlight {
  color: var(--accent);
}

.hero-content p {
  font-size: 1.25rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

/* --- Buttons --- */
.btn {
  display: inline-block;
  background-color: var(--text-main);
  color: var(--bg-primary);
  padding: 0.75rem 1.5rem;
  text-decoration: none;
  font-weight: 500;
  border-radius: 4px;
  transition: background-color var(--transition-speed);
}

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

/* --- Projects Container Layout --- */
.projects-container {
  padding: 5rem 10%;
}

.group-header {
  margin-bottom: 3rem;
}

.group-header h2 {
  font-size: 2rem;
  letter-spacing: -0.5px;
  margin-bottom: 0.5rem;
}

.group-header p {
  color: var(--text-muted);
  font-size: 1.1rem;
}

/* --- Grid Architecture --- */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.project-card {
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 2rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition:
    transform var(--transition-speed),
    border-color var(--transition-speed),
    box-shadow var(--transition-speed);
}

.project-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.05);
}

.project-card h3 {
  font-size: 1.35rem;
  margin-bottom: 0.75rem;
}

/* --- Tech Specifications Tags --- */
.project-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.project-tech span {
  font-size: 0.75rem;
  background-color: var(--bg-secondary);
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  font-weight: 600;
  color: var(--text-muted);
}

.project-link {
  text-decoration: none;
  color: var(--accent);
  font-weight: 600;
  font-size: 0.95rem;
}

.project-link:hover {
  text-decoration: underline;
}

/* --- Contact Section --- */
.contact-section {
  background-color: var(--bg-secondary);
  padding: 5rem 10%;
  text-align: center;
}

.contact-section h2 {
  font-size: 2rem;
  margin-bottom: 1rem;
}

.contact-section p {
  color: var(--text-muted);
  margin-bottom: 2rem;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

/* --- Footer --- */
.footer {
  text-align: center;
  padding: 2rem;
  border-top: 1px solid var(--border-color);
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* --- Mobile Breakpoints --- */
@media (max-width: 768px) {
  .navbar {
    padding: 1rem 5%;
  }
  .hero-section {
    padding: 0 5%;
    min-height: 45vh;
  }
  .hero-content h1 {
    font-size: 2.25rem;
  }
  .projects-container,
  .contact-section {
    padding: 4rem 5%;
  }
  .nav-links {
    gap: 1rem;
  }
}