/* ===== Variables ===== */
:root {
  --bg: #0a0a0a;
  --bg-alt: #111111;
  --surface: #1a1a1a;
  --border: #2a2a2a;
  --text: #e5e5e5;
  --text-muted: #999999;
  --accent: #60a5fa;
  --accent-hover: #93c5fd;
  --accent-dim: rgba(96, 165, 250, 0.1);
  --font: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --max-w: 1100px;
  --radius: 8px;
}

/* ===== Reset ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }
ul { list-style: none; }

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

/* ===== Nav ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(10, 10, 10, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}
.nav-logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text);
  letter-spacing: -0.02em;
}
.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a {
  color: var(--text-muted);
  font-size: 0.875rem;
  font-weight: 500;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--text); }
.lang-btn {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--accent);
  padding: 4px 12px;
  border-radius: 4px;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font);
  transition: all 0.2s;
}
.lang-btn:hover { background: var(--accent-dim); }

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 60px;
}
.hero-avatar {
  border-radius: 50%;
  border: 3px solid var(--accent);
  margin-bottom: 24px;
  box-shadow: 0 0 30px rgba(96, 165, 250, 0.2);
}
.hero-greeting {
  font-size: 1.1rem;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 12px;
}
.hero-name {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 12px;
}
.hero-title {
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  color: var(--text-muted);
  font-weight: 500;
  margin-bottom: 24px;
}
.hero-desc {
  max-width: 600px;
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-bottom: 32px;
  line-height: 1.8;
}
.hero-links { display: flex; gap: 12px; flex-wrap: wrap; }

/* ===== Buttons ===== */
.btn {
  display: inline-block;
  padding: 10px 24px;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 500;
  transition: all 0.2s;
  font-family: var(--font);
}
.btn-primary {
  background: var(--accent);
  color: #0a0a0a;
}
.btn-primary:hover { background: var(--accent-hover); color: #0a0a0a; }
.btn-secondary {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
}
.btn-secondary:hover { border-color: var(--accent); color: var(--accent); }

/* ===== Sections ===== */
.section {
  padding: 100px 0;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.section.visible { opacity: 1; transform: none; }
.section-alt { background: var(--bg-alt); }
.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 48px;
  letter-spacing: -0.02em;
  position: relative;
  display: inline-block;
}
.section-title::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 40px;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
}

/* ===== About ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}
.about-text p {
  color: var(--text-muted);
  margin-bottom: 16px;
  font-size: 0.95rem;
}
.about-highlights {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.highlight-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  opacity: 0;
  transform: translateY(10px);
  transition: all 0.4s ease;
}
.highlight-card.visible { opacity: 1; transform: none; }
.highlight-number {
  display: block;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 4px;
}
.highlight-label {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ===== Timeline ===== */
.timeline { position: relative; padding-left: 32px; }
.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border);
}
.timeline-item {
  position: relative;
  margin-bottom: 40px;
  opacity: 0;
  transform: translateX(-10px);
  transition: all 0.5s ease;
}
.timeline-item.visible { opacity: 1; transform: none; }
.timeline-marker {
  position: absolute;
  left: -32px;
  top: 6px;
  width: 14px;
  height: 14px;
  background: var(--accent);
  border-radius: 50%;
  border: 3px solid var(--bg-alt);
}
.timeline-content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}
.timeline-header { margin-bottom: 16px; }
.timeline-header h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 4px;
}
.timeline-company {
  display: block;
  color: var(--accent);
  font-size: 0.9rem;
  font-weight: 500;
}
.timeline-date {
  display: block;
  color: var(--text-muted);
  font-size: 0.8rem;
  margin-top: 2px;
}
.timeline-content ul {
  margin-bottom: 16px;
}
.timeline-content li {
  color: var(--text-muted);
  font-size: 0.9rem;
  padding-left: 16px;
  position: relative;
  margin-bottom: 8px;
}
.timeline-content li::before {
  content: '>';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 600;
}

/* ===== Tech Tags ===== */
.tech-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.tech-tags span {
  background: var(--accent-dim);
  color: var(--accent);
  padding: 2px 10px;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 500;
}

/* ===== Skills ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.skill-category {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}
.skill-category h3 {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.skill-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.skill-tag {
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.82rem;
  font-weight: 500;
  transition: all 0.2s;
}
.skill-tag:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ===== Projects ===== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
.project-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  display: block;
  color: var(--text);
  transition: all 0.3s ease;
  opacity: 0;
  transform: translateY(10px);
}
.project-card.visible { opacity: 1; transform: none; }
.project-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  color: var(--text);
}
.project-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}
.project-header h3 { font-size: 1.05rem; font-weight: 600; }
.project-arrow {
  color: var(--text-muted);
  font-size: 1.2rem;
  transition: all 0.2s;
}
.project-card:hover .project-arrow { color: var(--accent); transform: translate(2px, -2px); }
.project-card p {
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: 16px;
  line-height: 1.6;
}

/* ===== Education & Languages ===== */
.edu-lang-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
}
.edu-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}
.edu-card h3 { font-size: 1.05rem; font-weight: 600; margin-bottom: 8px; }
.edu-school { color: var(--accent); font-size: 0.9rem; }
.edu-date { color: var(--text-muted); font-size: 0.85rem; margin-top: 4px; }
.edu-gpa { color: var(--text); font-weight: 600; margin-top: 12px; font-size: 0.95rem; }

.lang-list { display: flex; flex-direction: column; gap: 20px; }
.lang-item { }
.lang-name { font-weight: 600; font-size: 0.95rem; }
.lang-level { color: var(--text-muted); font-size: 0.82rem; margin-left: 8px; }
.lang-bar {
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  margin-top: 8px;
  overflow: hidden;
}
.lang-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 3px;
  transition: width 1s ease;
}

/* ===== Contact ===== */
.contact-section { text-align: center; }
.contact-desc {
  color: var(--text-muted);
  max-width: 500px;
  margin: 0 auto 32px;
  font-size: 1rem;
}
.contact-links { display: flex; justify-content: center; gap: 12px; flex-wrap: wrap; }

/* ===== Footer ===== */
.footer {
  padding: 32px 0;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--text-muted);
  font-size: 0.82rem;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav-links a:not(.lang-btn) { display: none; }
  .about-grid { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: 1fr; }
  .projects-grid { grid-template-columns: 1fr; }
  .edu-lang-grid { grid-template-columns: 1fr; }
  .hero { min-height: 80vh; }
  .section { padding: 60px 0; }
}

@media (max-width: 480px) {
  .about-highlights { grid-template-columns: 1fr; }
  .hero-name { font-size: 2rem; }
}