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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  color: #2d3748;
  background: #ffffff;
  line-height: 1.7;
}

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid #edf2f7;
  z-index: 100;
}

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

.logo {
  font-size: 20px;
  font-weight: 700;
  color: #3182ce;
  text-decoration: none;
}

.nav nav {
  display: flex;
  gap: 28px;
}

.nav nav a {
  color: #4a5568;
  text-decoration: none;
  font-size: 15px;
  transition: color 0.2s;
}

.nav nav a:hover {
  color: #3182ce;
}

/* Hero */
.hero {
  padding: 96px 0 72px;
  text-align: center;
  background: linear-gradient(180deg, #ebf8ff 0%, #ffffff 100%);
}

.hero-inner h1 {
  font-size: 42px;
  margin: 24px 0 12px;
  font-weight: 700;
}

.hero-inner h1 strong {
  color: #3182ce;
}

.tagline {
  font-size: 18px;
  color: #718096;
  margin-bottom: 36px;
}

.avatar {
  font-size: 72px;
  line-height: 1;
}

.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 8px;
  text-decoration: none;
  font-size: 15px;
  transition: transform 0.2s, box-shadow 0.2s;
}

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

.btn-primary {
  background: #3182ce;
  color: #ffffff;
  margin-right: 12px;
  box-shadow: 0 4px 12px rgba(49, 130, 206, 0.3);
}

.btn-outline {
  border: 1px solid #3182ce;
  color: #3182ce;
}

/* Sections */
.section {
  padding: 80px 0;
}

.section.alt {
  background: #f7fafc;
}

.section-title {
  font-size: 28px;
  text-align: center;
  margin-bottom: 12px;
  position: relative;
  padding-bottom: 16px;
}

.section-title::after {
  content: "";
  display: block;
  width: 48px;
  height: 3px;
  background: #3182ce;
  margin: 0 auto;
  border-radius: 2px;
}

.lead {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 40px;
  color: #4a5568;
  font-size: 16px;
}

/* About facts */
.facts {
  display: flex;
  justify-content: center;
  gap: 60px;
  text-align: center;
  flex-wrap: wrap;
}

.fact strong {
  display: block;
  font-size: 36px;
  color: #3182ce;
}

.fact span {
  color: #718096;
  font-size: 14px;
}

/* Skills */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin-top: 40px;
}

.skill {
  background: #ffffff;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  padding: 32px 24px;
  text-align: center;
  transition: box-shadow 0.2s, transform 0.2s;
}

.skill:hover {
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
  transform: translateY(-4px);
}

.skill-icon {
  font-size: 36px;
  display: block;
  margin-bottom: 12px;
}

.skill h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.skill p {
  color: #718096;
  font-size: 14px;
}

/* Projects */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
  margin-top: 40px;
}

.project {
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  padding: 28px 24px;
  background: #ffffff;
  transition: box-shadow 0.2s, transform 0.2s;
}

.project:hover {
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
  transform: translateY(-4px);
}

.project h3 {
  font-size: 18px;
  margin-bottom: 12px;
  color: #2d3748;
}

.project p {
  color: #718096;
  font-size: 14px;
  margin-bottom: 16px;
}

.project-link {
  color: #3182ce;
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
}

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

/* Contact */
.contact-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
  margin-top: 24px;
}

.contact-item {
  display: inline-block;
  padding: 14px 28px;
  border: 1px solid #e2e8f0;
  border-radius: 8px;
  background: #ffffff;
  text-decoration: none;
  color: #4a5568;
  font-size: 15px;
  transition: border-color 0.2s, color 0.2s;
}

.contact-item:hover {
  border-color: #3182ce;
  color: #3182ce;
}

/* Footer */
.site-footer {
  border-top: 1px solid #edf2f7;
  padding: 32px 0;
  text-align: center;
  color: #a0aec0;
  font-size: 14px;
}

/* Responsive */
@media (max-width: 768px) {
  .hero {
    padding: 64px 0 48px;
  }

  .hero-inner h1 {
    font-size: 30px;
  }

  .nav nav {
    gap: 16px;
  }

  .facts {
    gap: 32px;
  }

  .contact-links {
    flex-direction: column;
    align-items: center;
  }
}