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

body {
  font-family: "Helvetica Neue", Arial, sans-serif;
  background: #f7f3ed;
  color: #1a1a1a;
  line-height: 1.6;
}

nav {
  background: #fff;
  border-bottom: 1px solid #e5e0d8;
  padding: 25px 0;
}

.nav-container {
  max-width: 1100px;
  margin: auto;
  padding: 0 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-weight: 600;
}

.nav-links {
  display: flex;
  gap: 30px;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: #6b6b6b;
}

.nav-links a.active {
  color: #1a1a1a;
}

.container {
  max-width: 1100px;
  margin: auto;
  padding: 80px 40px;
}

.page {
  display: none;
}

.page.active {
  display: block;
}

.hero h1 {
  font-size: 3em;
  font-weight: 300;
  margin-bottom: 20px;
}

.hero p {
  margin-bottom: 40px;
  color: #4a4a4a;
}

.hero button {
  background: #1a1a1a;
  color: #fff;
  border: none;
  padding: 14px 36px;
  cursor: pointer;
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 40px;
}

.blog-card {
  background: #fff;
  padding: 30px;
  cursor: pointer;
  transition: transform 0.2s;
}

.blog-card:hover {
  transform: translateY(-5px);
}

.blog-detail h2 {
  font-size: 2.4em;
  margin-bottom: 10px;
}

.blog-detail .post-body {
  margin: 40px 0;
}

footer {
  text-align: center;
  padding: 50px 20px;
  color: #9a9a9a;
}

.hidden {
  display: none;
}

/* ===== モバイル対応 ===== */
@media (max-width: 768px) {

  .nav-container {
    flex-direction: column;
    gap: 20px;
    padding: 0 20px;
  }

  .container {
    padding: 40px 20px;
  }

  .hero h1 {
    font-size: 2.2em;
  }

  .blog-grid {
    grid-template-columns: 1fr;
  }

  .blog-card {
    padding: 20px;
  }
}