/* ==============================================
   common.css
   ヘッダー・フッター・CSS変数・ベーススタイル
   blog.css / dictionary.css / guide.css / tools
   など全ページで共通して読み込む
   ============================================== */

/* ── CSS 変数 ── */
:root {
  --teal:       #21c4a6;
  --teal-dark:  #024560;
  --teal-light: #e6faf6;
  --ink:        #1f2937;
  --ink-sub:    #6b7280;
  --border:     #e5e7eb;
  --bg:         #f9fafb;
  --white:      #ffffff;
}

/* ── リセット ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: 'Hiragino Sans', 'Noto Sans JP', sans-serif;
  color: var(--ink);
  background: var(--white);
  line-height: 1.7;
}

/* ── Header ── */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--white);
  border-bottom: 1px solid var(--border);
}
.header-container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo { text-decoration: none; display: flex; align-items: center; }
.logo-image { height: 28px; }
.header-nav { display: flex; gap: 24px; align-items: center; }
.nav-link {
  font-size: .9rem;
  color: var(--ink-sub);
  text-decoration: none;
  transition: color .2s;
}
.nav-link:hover,
.nav-link.active { color: var(--teal-dark); font-weight: 600; }
.header-cta {
  background: var(--teal-dark);
  color: #fff !important;
  padding: 7px 18px;
  border-radius: 20px;
  font-size: .88rem;
  font-weight: 600;
  text-decoration: none;
  transition: opacity .2s;
  white-space: nowrap;
}
.header-cta:hover { opacity: .85; }

/* ── Footer ── */
.footer {
  background: #1a202c;
  color: rgba(255,255,255,.7);
  font-size: .85rem;
  padding: 40px 0 24px;
  margin-top: 64px;
}
.w1200 { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 32px;
  margin-bottom: 32px;
}
.footer__logo { margin-bottom: 12px; }
.footer__logo img { filter: brightness(0) invert(1); opacity: .85; }
.footer__desc { font-size: .82rem; line-height: 1.6; }
.footer__col-title { font-weight: 700; color: #fff; margin-bottom: 12px; }
.footer__links { list-style: none; display: flex; flex-direction: column; gap: 8px; }
.footer__links a { color: rgba(255,255,255,.6); text-decoration: none; transition: color .2s; }
.footer__links a:hover { color: #fff; }
.footer__bottom {
  border-top: 1px solid rgba(255,255,255,.1);
  padding-top: 16px;
  display: flex;
  justify-content: space-between;
  font-size: .8rem;
  color: rgba(255,255,255,.4);
}

/* ── レスポンシブ ── */
@media (max-width: 768px) {
  .header-nav .nav-link:not(.header-cta) { display: none; }
  .footer__grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 480px) {
  .footer__grid { grid-template-columns: 1fr; }
  .footer__bottom { flex-direction: column; gap: 4px; }
}