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

:root {
  --bg: #0f1117;
  --bg-card: #1a1d27;
  --bg-card-hover: #222632;
  --text: #e4e4e7;
  --text-muted: #9ca3af;
  --accent: #60a5fa;
  --accent-hover: #93bbfd;
  --border: #2a2d3a;
  --tag-bg: #1e293b;
  --tag-text: #94a3b8;
  --max-width: 1100px;
  --radius: 8px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s;
}

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

img {
  max-width: 100%;
  display: block;
}

/* ===== Layout ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Navbar ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 17, 23, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 16px 0;
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.navbar-brand {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--text);
}

.navbar-brand:hover {
  color: var(--accent);
}

.navbar-links {
  display: flex;
  gap: 28px;
  list-style: none;
}

.navbar-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s;
}

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

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

@media (max-width: 640px) {
  .nav-toggle {
    display: block;
  }
  .navbar-links {
    display: none;
    flex-direction: column;
    gap: 12px;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 16px 24px;
  }
  .navbar-links.open {
    display: flex;
  }
}

/* ===== Hero ===== */
.hero {
  padding: 80px 0 60px;
  text-align: center;
}

.hero-avatar {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  margin: 0 auto 24px;
  border: 3px solid var(--border);
}

.hero h1 {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

.hero .subtitle {
  font-size: 1.125rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 16px;
}

.hero .tagline {
  font-size: 1rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 28px;
  line-height: 1.7;
}

.hero-links {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 600;
  transition: all 0.2s;
  border: 1px solid var(--border);
  color: var(--text);
  background: var(--bg-card);
}

.btn:hover {
  background: var(--bg-card-hover);
  color: var(--text);
  border-color: var(--accent);
}

.btn-primary {
  background: var(--accent);
  color: var(--bg);
  border-color: var(--accent);
}

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

/* ===== Section ===== */
.section {
  padding: 60px 0;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.section-subtitle {
  color: var(--text-muted);
  margin-bottom: 36px;
  font-size: 0.95rem;
}

/* ===== Project Cards ===== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
}

.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  display: flex;
  flex-direction: column;
  transition: border-color 0.2s, transform 0.2s;
}

.project-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.project-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.project-card h3 a {
  color: var(--text);
}

.project-card h3 a:hover {
  color: var(--accent);
}

.project-card p {
  color: var(--text-muted);
  font-size: 0.875rem;
  line-height: 1.65;
  margin-bottom: 16px;
  flex-grow: 1;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 16px;
}

.tag {
  background: var(--tag-bg);
  color: var(--tag-text);
  padding: 3px 10px;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 500;
}

.project-links {
  display: flex;
  gap: 12px;
  margin-top: auto;
}

.project-links a {
  font-size: 0.825rem;
  font-weight: 600;
}

/* ===== Skills ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 20px;
}

.skill-group {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}

.skill-group h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--accent);
}

.skill-group ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.skill-group li {
  background: var(--tag-bg);
  color: var(--tag-text);
  padding: 4px 12px;
  border-radius: 4px;
  font-size: 0.8rem;
}

/* ===== Contact / Footer ===== */
.footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-links {
  display: flex;
  gap: 20px;
  justify-content: center;
  margin-bottom: 12px;
}

/* ===== Project Detail Page ===== */
.project-detail {
  padding: 60px 0 80px;
  max-width: 780px;
  margin: 0 auto;
}

.project-detail .back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: 32px;
}

.project-detail .back-link:hover {
  color: var(--accent);
}

.project-detail h1 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 16px;
  letter-spacing: -0.01em;
}

.project-detail .project-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 24px;
}

.project-detail .summary {
  font-size: 1.05rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 36px;
}

.detail-section {
  margin-bottom: 32px;
}

.detail-section h2 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.detail-section p,
.detail-section li {
  color: var(--text-muted);
  font-size: 0.925rem;
  line-height: 1.7;
}

.detail-section ul {
  padding-left: 20px;
  margin-top: 8px;
}

.detail-section li {
  margin-bottom: 6px;
}

.detail-section code {
  background: var(--tag-bg);
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 0.85em;
  color: var(--accent);
}

.detail-links {
  display: flex;
  gap: 12px;
  margin-top: 40px;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .hero {
    padding: 50px 0 40px;
  }
  .hero h1 {
    font-size: 1.75rem;
  }
  .projects-grid {
    grid-template-columns: 1fr;
  }
  .project-detail {
    padding: 40px 24px 60px;
  }
  .project-detail h1 {
    font-size: 1.5rem;
  }
}