:root {
  --bg: #f8f9fb;
  --bg-content: #ffffff;
  --border: #dde1e7;
  --accent: #2563eb;
  --text-main: #111827;
  --text-sub: #6b7280;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont,
               "Helvetica Neue", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text-main);
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* 共通：ページ上部ナビ（TOP/HELP/PRIVACY） */
.topnav {
  max-width: 980px;
  margin: 0 auto;
  padding: 14px 16px 0;
}
.topnav-inner{
  display:flex;
  gap:10px;
  align-items:center;
  justify-content:space-between;
}
.brand {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-main);
}
.topnav-links {
  display:flex;
  gap:10px;
  flex-wrap: wrap;
}
.topnav-links a {
  font-size: 13px;
  padding: 8px 10px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: #fff;
}
.topnav-links a:hover { background:#e5efff; text-decoration:none; }

/* 共通：シンプルページ（TOP/Privacy用） */
.simple-page {
  padding: 14px 16px 40px;
}
.simple-inner {
  max-width: 880px;
  margin: 0 auto;
  background: var(--bg-content);
  border-radius: 12px;
  border: 1px solid var(--border);
  padding: 24px 20px 32px;
  box-shadow: 0 8px 18px rgba(15, 23, 42, 0.06);
}

/* 共通：動画のレスポンシブ枠 */
.video-wrap {
  margin: 14px 0 20px;
}

/* 共通：ボタン（リンク） */
.cta-row { display:flex; gap:10px; flex-wrap:wrap; margin: 14px 0 6px; }
.cta {
  display:inline-block;
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text-main);
  font-size: 14px;
}
.cta.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
  font-weight: 600;
}
.cta:hover { text-decoration:none; background:#e5efff; }
.cta.primary:hover { background: #1d4ed8; }

/* ===== ヘルプページ（サイドバー＋本文カード） ===== */
.layout { display: flex; min-height: 100vh; }

/* サイドバー */
.sidebar {
  width: 250px;
  border-right: 1px solid var(--border);
  background: #f1f5f9;
  padding: 16px 12px;
  position: sticky;
  top: 0;
  align-self: flex-start;
  max-height: 100vh;
  overflow-y: auto;
}

.app-title { font-size: 18px; font-weight: 600; margin-bottom: 4px; }
.app-subtitle { font-size: 12px; color: var(--text-sub); margin-bottom: 16px; }

.nav-section-title {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-sub);
  margin: 16px 6px 4px;
  text-transform: uppercase;
  letter-spacing: .08em;
  padding: 4px 6px;
  border-radius: 6px;
  background: transparent;
  user-select: none;
  -webkit-user-select: none;
}
.nav-section-title:active { background: #e5efff; }

.nav-list { list-style: none; margin: 0 0 0 4px; padding: 0; }
.nav-item { margin: 2px 0; }

.nav-button {
  width: 100%;
  border: none;
  background: none;
  text-align: left;
  padding: 8px 10px;
  border-radius: 6px;
  font-size: 14px;
  cursor: pointer;
  color: var(--text-main);
}
.nav-button:hover { background: #e5efff; }
.nav-button.active { background: var(--accent); color: #ffffff; font-weight: 600; }

/* メインコンテンツ */
.content { flex: 1; padding: 20px 20px 40px; }
.content-inner {
  max-width: 880px;
  margin: 0 auto;
  background: var(--bg-content);
  border-radius: 12px;
  border: 1px solid var(--border);
  padding: 24px 20px 32px;
  box-shadow: 0 8px 18px rgba(15, 23, 42, 0.06);
}

.page { display: none; }
.page.active { display: block; }

/* タイポ */
h1 { font-size: 22px; margin: 0 0 4px; }
.page-lead { font-size: 14px; color: var(--text-sub); margin-bottom: 20px; }

h2 {
  font-size: 18px;
  margin: 24px 0 8px;
  border-left: 3px solid var(--accent);
  padding-left: 8px;
}
h3 { font-size: 16px; margin: 16px 0 6px; }

p { font-size: 14px; line-height: 1.6; margin: 4px 0 10px; }
ul, ol { font-size: 14px; padding-left: 1.4em; margin: 4px 0 10px; }

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
               "Liberation Mono", "Courier New", monospace;
  font-size: 13px;
  background: #f3f4f6;
  padding: 2px 4px;
  border-radius: 4px;
}

.note {
  border-left: 3px solid #f59e0b;
  background: #fffbeb;
  border-radius: 6px;
  padding: 8px 10px;
  font-size: 13px;
  margin: 8px 0 14px;
}

.screenshot { margin: 10px 0 16px; text-align: center; }
.screenshot img { max-width: 100%; border-radius: 8px; border: 1px solid var(--border); }
.screenshot-caption { font-size: 12px; color: var(--text-sub); margin-top: 4px; }

/* チャート操作ページのミニ目次 */
.chart-toc {
  font-size: 13px;
  background: #f9fafb;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 10px;
  margin-bottom: 16px;
}
.chart-toc-title { font-weight: 600; margin-bottom: 4px; color: var(--text-sub); }
.chart-toc ul { margin: 4px 0 0; padding-left: 1.2em; }

/* FAQ */
details {
  border-radius: 8px;
  border: 1px solid var(--border);
  background: #f9fafb;
  margin: 8px 0;
  padding: 8px 10px;
}
summary {
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  list-style: none;
}
summary::-webkit-details-marker { display: none; }
summary::before {
  content: "Q";
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border-radius: 999px;
  background: #e5e7eb;
  font-size: 11px;
  margin-right: 8px;
}
details[open] summary::before { background: var(--accent); color: #fff; }
details p { margin-top: 8px; }

/* スマホ対応 */
@media (max-width: 800px) {
  .layout { flex-direction: column; }
  .sidebar {
    width: 100%;
    position: static;
    display: block;
    border-right: none;
    border-bottom: 1px solid var(--border);
    padding: 12px 10px;
  }
  .nav-section-title { display: none; }

  .app-title { font-size: 17px; margin-bottom: 2px; }
  .app-subtitle { margin-bottom: 10px; }

  .nav-list { list-style: none; margin: 0; padding: 0; }
  .nav-item { margin: 2px 0; }
  .nav-button { width: 100%; font-size: 15px; padding: 10px; }

  .content { padding: 10px; }
  .content-inner {
    padding: 18px 14px 24px;
    border-radius: 0;
    max-width: 100%;
    margin: 0;
    border-left: none;
    border-right: none;
  }

  h1 { font-size: 20px; }
  p, ul, ol { font-size: 15px; }

  .simple-page { padding: 10px; }
  .simple-inner {
    padding: 18px 14px 24px;
    border-radius: 0;
    max-width: 100%;
    margin: 0;
    border-left: none;
    border-right: none;
  }
}