* {
  box-sizing: border-box;
}
body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: #f7f8fa;
  color: #222;
}
main {
  max-width: 900px;
  margin: 32px auto;
  background: #fff;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  padding: 24px;
  line-height: 1.6;
}
h1, h2, h3 {
  line-height: 1.3;
}
a {
  color: #0b57d0;
}
ul {
  padding-left: 20px;
}
li {
  margin: 6px 0;
}
hr {
  border: 0;
  border-top: 1px solid #e5e7eb;
  margin: 24px 0;
}
.card {
  background: #f9fafb;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  padding: 16px;
}
.muted {
  color: #555;
}
code {
  background: #f3f4f6;
  padding: 2px 6px;
  border-radius: 6px;
}
.app-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 24px;
}
.app-card {
  display: block;
  text-decoration: none;
  color: inherit;
  padding: 24px;
  background: #fff;
  border: 1px solid #e5e7eb;
  border-radius: 12px;
  transition: box-shadow 0.2s, transform 0.2s;
}
.app-card:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}
.app-card h2 {
  margin: 0 0 4px 0;
  font-size: 1.3rem;
}
.app-card p {
  margin: 0;
  color: #666;
  font-size: 0.9rem;
}