:root {
  --font-main: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.theme-light {
  --bg: #ffffff;
  --fg: #111827;
  --muted: #6b7280;
  --border: #e5e7eb;
  --card-bg: #f9fafb;
  --accent: #1d4ed8;
  --hover: #dbeafe;
  --shadow: rgba(0,0,0,0.05);
}

.theme-dark {
  --bg: #0b0f19;
  --fg: #f1f5f9;
  --muted: #94a3b8;
  --border: #1e293b;
  --card-bg: #121a27;
  --accent: #60a5fa;
  --hover: #1e3a8a;
  --shadow: rgba(0,0,0,0.25);
}

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

body {
  background-color: var(--bg);
  color: var(--fg);
  font-family: var(--font-main);
  line-height: 1.6;
  transition: var(--transition);
}

.layout {
  max-width: 900px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
.header {
  text-align: center;
  margin-bottom: 3.5rem;
  position: relative;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 1rem;
}

.name {
  font-size: 2.8rem;
  font-weight: 800;
  letter-spacing: -1px;
  background: linear-gradient(90deg, var(--fg), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.controls {
  display: flex;
  gap: 0.6rem;
}

.control-btn {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
  color: var(--fg);
  font-weight: 600;
  font-size: 0.85rem;
}

.control-btn:hover {
  background: var(--hover);
  transform: translateY(-2px);
}

.lang-btn {
  width: auto;
  padding: 0 12px;
}

.icon { display: none; }
.theme-light .icon.sun { display: inline; }
.theme-dark .icon.moon { display: inline; }

.tagline {
  font-size: 1.2rem;
  font-weight: 500;
  color: var(--muted);
  max-width: 600px;
  margin: 0 auto;
}

/* Sections */
.section {
  margin-bottom: 3.5rem;
  opacity: 0;
  transform: translateY(20px);
  animation: fadeInUp 0.6s forwards;
}

@keyframes fadeInUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.section-title {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 50px;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
}

/* Expertise Grid */
.expertise-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.4rem;
  margin-top: 1.2rem;
}

.expertise-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.4rem;
  transition: var(--transition);
}

.expertise-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 25px var(--shadow);
  border-color: var(--accent);
}

.card-icon {
  font-size: 2rem;
  margin-bottom: 0.8rem;
}

.expertise-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
  color: var(--fg);
}

.expertise-card p {
  font-size: 0.95rem;
  color: var(--muted);
  line-height: 1.5;
}

/* Contact */
.contact-list {
  display: flex;
  flex-wrap: wrap;
  gap: 1.2rem;
  margin-top: 1rem;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  transition: var(--transition);
}

.contact-item:hover {
  background: var(--hover);
  transform: translateX(4px);
}

/* Footer */
.footer {
  margin-top: auto;
  padding-top: 2rem;
  text-align: center;
  color: var(--muted);
  font-size: 0.95rem;
  border-top: 1px solid var(--border);
}

/* Responsive */
@media (max-width: 768px) {
  .header-content { flex-direction: column; gap: 1rem; align-items: center; }
  .name { font-size: 2.2rem; }
  .tagline { font-size: 1.05rem; }
  .controls { width: 100%; justify-content: center; }
}