:root {
  --color-primary: #3ecc5f;       /* Tripper Green */
  --color-primary-dark: #2da148;
  --color-text: #1c1e21;
  --color-bg: #ffffff;
  --color-bg-alt: #f5f6f7;
  --nav-height: 60px;
  --sidebar-width: 280px;
}

body {
  font-family: system-ui, -apple-system, Segoe UI, sans-serif;
  color: var(--color-text);
  margin: 0;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  line-height: 1.6;
}

/* リンク */
a { text-decoration: none; color: inherit; transition: 0.2s; }
a:hover { color: var(--color-primary); }

/* ヘッダー */
header.navbar {
  height: var(--nav-height);
  display: flex;
  align-items: center;
  padding: 0 2rem;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
  position: sticky;
  top: 0;
  background: #fff;
  z-index: 100;
}
.navbar-brand { font-weight: 800; font-size: 1.4rem; display: flex; align-items: center; gap: 10px; }
.navbar-items { margin-left: auto; display: flex; gap: 1.5rem; font-weight: 600; }

/* ヒーローセクション */
.hero {
  text-align: center;
  padding: 4rem 1rem 6rem;
  background-color: var(--color-primary);
  color: white;
}
.hero h1 { font-size: 3.5rem; margin-bottom: 1rem; }
.hero p { font-size: 1.5rem; margin-bottom: 2rem; opacity: 0.9; }
.button-group { display: flex; justify-content: center; gap: 1rem; }
.button {
  padding: 0.8rem 2rem;
  border-radius: 30px;
  font-weight: bold;
  background: white;
  color: var(--color-primary);
  border: 2px solid white;
}
.button.outline { background: transparent; color: white; }
.button:hover { opacity: 0.9; transform: translateY(-2px); }

/* コンテナ */
.container { max-width: 1100px; margin: 0 auto; padding: 2rem 1rem; }

/* 機能紹介 (3カラム) */
.features { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 3rem; margin: 3rem 0; }
.feature-item { text-align: center; }
.feature-svg { height: 200px; width: auto; margin-bottom: 1rem; } /* SVG用プレースホルダー */

/* カード (お客様の声など) */
.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.5rem; }
.card { padding: 1.5rem; border-radius: 8px; box-shadow: 0 4px 10px rgba(0,0,0,0.1); background: white; }
.card h3 { color: var(--color-primary); margin-top: 0; }
.card-footer { margin-top: 1rem; font-size: 0.9rem; color: #666; font-style: italic; text-align: right; }

/* ドキュメントレイアウト */
.doc-layout { display: flex; max-width: 1400px; margin: 0 auto; width: 100%; }
.sidebar {
  width: var(--sidebar-width);
  border-right: 1px solid #eee;
  height: calc(100vh - var(--nav-height));
  position: sticky;
  top: var(--nav-height);
  padding: 1.5rem;
  overflow-y: auto;
}
.sidebar ul { list-style: none; padding: 0; }
.sidebar li a { display: block; padding: 0.5rem; color: #555; }
.sidebar li a.active { color: var(--color-primary); font-weight: bold; border-left: 3px solid var(--color-primary); padding-left: 0.3rem; }
.doc-content { flex: 1; padding: 2rem 4rem; max-width: 800px; }

/* ブログレイアウト */
.blog-post { max-width: 800px; margin: 0 auto 4rem; padding-bottom: 2rem; border-bottom: 1px solid #eee; }
.blog-date { color: #666; font-size: 0.9rem; }

/* フッター */
footer { background: #1b1b1d; color: #fff; padding: 3rem; text-align: center; margin-top: auto; }
footer a { color: #fff; text-decoration: underline; }