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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  background: #f0f2f5;
  color: #1f2937;
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ---- 导航栏 ---- */
.navbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 2rem;
  height: 60px;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid #e5e7eb;
}

.nav-brand {
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: 0.02em;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

.nav-links a {
  text-decoration: none;
  color: #4b5563;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
  color: #2563eb;
}

/* ---- 主容器 ---- */
main {
  flex: 1;
  width: 100%;
  max-width: 720px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ---- Hero 区域 ---- */
.hero {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 50vh;
  text-align: center;
}

.hero-content h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.highlight {
  color: #2563eb;
}

.subtitle {
  font-size: 1.15rem;
  color: #6b7280;
}

/* ---- 通用 Section ---- */
.section {
  margin-bottom: 2.5rem;
  scroll-margin-top: 80px;
}

/* ---- 卡片 ---- */
.card {
  background: #fff;
  border-radius: 12px;
  padding: 2rem 2.25rem;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
  transition: box-shadow 0.25s;
}

.card:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.card h2 {
  font-size: 1.4rem;
  margin-bottom: 1rem;
  color: #111827;
}

.card p {
  color: #4b5563;
}

/* ---- 项目列表 ---- */
.project-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.project-list li {
  padding: 0.75rem 1rem;
  background: #f9fafb;
  border-radius: 8px;
  font-size: 0.95rem;
  color: #4b5563;
}

.project-list li strong {
  color: #1f2937;
}

/* ---- 页脚 ---- */
.footer {
  text-align: center;
  padding: 2rem 1.5rem;
  font-size: 0.85rem;
  color: #9ca3af;
  border-top: 1px solid #e5e7eb;
  margin-top: 2rem;
}

/* ---- Responsive ---- */
@media (max-width: 540px) {
  .navbar {
    padding: 0 1rem;
  }

  .hero-content h1 {
    font-size: 1.75rem;
  }

  .card {
    padding: 1.5rem;
  }
}