* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
  background: #f4f5f7;
  color: #202124;
}

header {
  background: #fff;
  border-bottom: 1px solid #e2e4e8;
}

.header-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 20px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
}

.logo {
  font-weight: 600;
  font-size: 18px;
  color: #202124;
  text-decoration: none;
}

nav {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

nav a {
  color: #555;
  text-decoration: none;
}

nav a:hover {
  color: #111;
}

main {
  max-width: 900px;
  margin: 48px auto;
  padding: 0 24px;
}

h1 {
  font-size: 32px;
  margin: 0 0 12px;
}

.subtitle {
  color: #666;
  margin-bottom: 34px;
  line-height: 1.6;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
}

.card {
  display: block;
  background: #fff;
  border: 1px solid #e5e7eb;
  border-radius: 12px;
  padding: 22px;
  color: inherit;
  text-decoration: none;
  box-shadow: 0 2px 8px rgba(0,0,0,.03);
}

.card:hover {
  border-color: #cfd2d7;
}

.card h2 {
  margin: 0 0 10px;
  font-size: 18px;
}

.card p, p {
  color: #666;
  line-height: 1.65;
}

footer {
  max-width: 900px;
  margin: 50px auto 20px;
  padding: 0 24px;
  color: #999;
  font-size: 13px;
}

@media (max-width: 650px) {
  .header-inner {
    align-items: flex-start;
    flex-direction: column;
  }
}