/* about.css — 「このサイトについて」ページ専用スタイル */

:root {
  --color-accent:      #2a7a00;
  --color-accent-bg:   #fff7cc;
  --color-header-bg:   #ffffff;
  --color-section-bg:  #ffffff;
  --color-border:      #cccccc;
  --color-text:        #333333;
  --color-text-muted:  #666666;
  --radius-sm: 4px;
  --radius-md: 8px;
  --transition-fast: 0.15s ease;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  font-family: sans-serif;
  margin: 0;
  padding: 0;
  background: var(--color-accent-bg);
  color: var(--color-text);
  line-height: 1.7;
}

/* ========ヘッダー======== */
.about-header {
  background: var(--color-header-bg);
  border-bottom: 3px solid var(--color-accent);
  padding: 10px 24px;
}

.about-header__inner {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  justify-content: center;
  align-items: center;
}

.about-title {
  margin: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  max-width: 100%;
}

.about-title__icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

/* タイトル画像（how_to_image.png） */
.about-title__text {
  display: block;
  height: 72px;
  width: auto;
  max-width: min(560px, calc(100% - 56px));
  object-fit: contain;
  object-position: center;
}

.about-subtitle {
  margin: 8px 0 0;
  font-size: 16px;
  color: var(--color-text-muted);
}

/* ========ページ内ナビ======== */
.about-nav {
  background: #532b00;
  padding: 12px 24px;
  position: sticky;
  top: 0;
  z-index: 10;
}

.about-nav__list {
  list-style: none;
  margin: 0 auto;
  padding: 0;
  max-width: 800px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
}

.about-nav__list a {
  color: #ffffff;
  text-decoration: none;
  font-size: 14px;
  font-weight: bold;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast);
}

.about-nav__list a:hover,
.about-nav__list a:focus-visible {
  background: rgba(255, 255, 255, 0.2);
  outline: none;
}

.about-nav__list a.is-active {
  background: #ffec8e;
  color: var(--color-accent);
}

/* ========メインコンテンツ======== */
.about-main {
  max-width: 800px;
  margin: 0 auto;
  padding: 24px 16px 48px;
}

.about-section {
  background: var(--color-section-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  margin-bottom: 24px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

.about-section h2 {
  margin: 0 0 16px;
  font-size: 22px;
  color: var(--color-accent);
  border-bottom: 2px solid var(--color-accent);
  padding-bottom: 8px;
}

.about-section h3 {
  margin: 20px 0 8px;
  font-size: 16px;
  color: var(--color-text);
}

.about-section p {
  margin: 0 0 12px;
}

.about-section ul,
.about-section ol {
  margin: 0 0 12px;
  padding-left: 1.4em;
}

.about-section li {
  margin-bottom: 6px;
}

.about-feature-list {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 8px;
  margin-top: 16px;
}

.about-feature-list li {
  background: var(--color-accent-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  margin: 0;
  font-size: 14px;
}

.about-steps {
  padding-left: 1.4em;
}

.about-steps li {
  margin-bottom: 12px;
}

/* ========フッター======== */
.about-footer {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 16px 32px;
  text-align: center;
}

.back-link {
  display: inline-block;
  background: #ffffff;
  color: var(--color-accent);
  border: 2px solid var(--color-accent);
  text-decoration: none;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-weight: bold;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.back-link:hover {
  background: var(--color-accent);
  color: #ffffff;
}

.about-footer__note {
  margin: 20px 0 0;
  color: var(--color-text-muted);
}

/* ========レスポンシブ======== */
@media (max-width: 600px) {
  .about-header {
    padding: 8px 16px;
  }

  .about-title {
    gap: 8px;
  }

  .about-title__text {
    height: 52px;
    max-width: calc(100% - 44px);
  }

  .about-title__icon {
    width: 32px;
    height: 32px;
  }

  .about-section {
    padding: 18px 16px;
  }

  .about-nav__list {
    justify-content: center;
  }
}