/* ベースリセット */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* 聖杯レイアウト */
body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
}

/* ── ヘッダー ── */
header {
  background-color: #fff;
  border-bottom: 1px solid #ddd;
  height: 60px;
  width: 100%;
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 100%;
  padding: 0 24px;
}

.logo a {
  font-size: 20px;
  font-weight: bold;
  text-decoration: none;
  color: #333;
}

.header-nav ul {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: 24px;
}

.header-nav a {
  text-decoration: none;
  color: #333;
  font-size: 14px;
  white-space: nowrap;
}

.header-nav a:hover {
  color: #0066cc;
}

/* ── 3カラム ── */
.wrapper {
  display: flex;
  flex: 1;
}

/* サイドナビ（ヘッダーnavと区別） */
.side-nav {
  width: 150px;
  background-color: rgb(200, 220, 200);
  padding: 16px;
  flex-shrink: 0;
}

.side-nav ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.side-nav a {
  display: block;
  padding: 8px 16px;
  text-decoration: none;
  color: #333;
  white-space: nowrap;
}

.side-nav a:hover {
  background-color: #ddd;
}

main {
  flex: 1;
  background-color: rgb(181, 148, 148);
  padding: 16px;
}

aside {
  width: 200px;
  background-color: rgb(200, 210, 230);
  padding: 16px;
  flex-shrink: 0;
}

aside h2 {
  font-size: 14px;
  margin-bottom: 8px;
  border-bottom: 1px solid #aaa;
  padding-bottom: 4px;
}

aside ul {
  list-style: none;
  padding: 0;
  margin: 0 0 16px 0;
}

aside li a {
  text-decoration: none;
  color: #333;
  font-size: 13px;
  line-height: 2;
}

aside li a:hover {
  color: #0066cc;
}

/* ── フッター ── */
footer {
  background-color: rgb(179, 186, 168);
  padding: 16px;
  min-height: 100px;
}

/* ── スマホ対応 ── */
@media screen and (max-width: 900px) {
  body {
    width: 100%;
  }

  .header-nav ul {
    gap: 12px;
  }

  .wrapper {
    flex-direction: column;
  }

  .side-nav,
  aside {
    width: 100%;
  }

  main {
    order: -1;
  }
}