/* ===================================================================
   グラフ先生 - 共通スタイル
   ビジネス / フレッシュ / 白ベース / ゴシック
   =================================================================== */

:root {
  /* Color */
  --bg: #ffffff;
  --bg-soft: #f6f8fb;
  --bg-muted: #eef1f6;
  --surface: #ffffff;
  --border: #e4e8ef;
  --border-strong: #cfd6e0;

  --text: #0b1220;
  --text-muted: #5b6576;
  --text-soft: #8a94a3;

  --primary: #0a5cff;
  --primary-dark: #0046cc;
  --primary-soft: #e7efff;

  --accent: #10b981;      /* ミントグリーン */
  --accent-soft: #def7ee;

  --warn: #f59e0b;
  --danger: #ef4444;

  /* Data colors */
  --c1: #0a5cff;
  --c2: #10b981;
  --c3: #f59e0b;
  --c4: #8b5cf6;
  --c5: #ef4444;
  --c6: #06b6d4;
  --c7: #ec4899;

  /* Typography */
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", ui-monospace, Menlo, Consolas, monospace;

  /* Shape */
  --radius-sm: 6px;
  --radius: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  /* Shadow */
  --shadow-sm: 0 1px 2px rgba(10, 17, 35, 0.04);
  --shadow: 0 2px 8px rgba(10, 17, 35, 0.06), 0 1px 2px rgba(10, 17, 35, 0.04);
  --shadow-md: 0 8px 24px rgba(10, 17, 35, 0.08);
  --shadow-lg: 0 20px 48px rgba(10, 17, 35, 0.12);

  /* Layout */
  --max-w: 1240px;
  --header-h: 64px;
  --sidebar-w: 280px;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: "palt";
}
body.menu-open { overflow: hidden; }
/* 本文の段落・リスト・FAQなど"自然な日本語の字間"が必要な箇所はpaltを解除 */
p, li, dd, dt, blockquote,
.faq-q, .faq-a,
.callout, .callout-title,
.use-case-desc, .use-case-title,
.graph-hero-sub, .footer-tagline, .footer-list a,
.section-text, .section-card p,
.note, .note-content {
  font-feature-settings: normal;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-sans);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text);
  margin: 0;
  line-height: 1.3;
}
h1 { font-size: clamp(32px, 5vw, 56px); letter-spacing: -0.025em; }
h2 { font-size: clamp(24px, 3.5vw, 36px); letter-spacing: -0.02em; }
h3 { font-size: 20px; }
h4 { font-size: 16px; }

p { margin: 0; }
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
img, svg { display: block; max-width: 100%; }
button { font: inherit; cursor: pointer; }

.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}
@media (max-width: 640px) { .container { padding: 0 16px; } }

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 14px;
  line-height: 1.2;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.15s ease;
  text-decoration: none;
  white-space: nowrap;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); color: #fff; transform: translateY(-1px); box-shadow: var(--shadow); }
.btn-secondary { background: #fff; color: var(--text); border-color: var(--border-strong); }
.btn-secondary:hover { border-color: var(--primary); color: var(--primary); }
.btn-ghost { background: transparent; color: var(--text); }
.btn-ghost:hover { background: var(--bg-muted); }
.btn-sm { padding: 7px 14px; font-size: 13px; }
.btn-lg { padding: 14px 24px; font-size: 15px; border-radius: 12px; }
.btn svg { width: 16px; height: 16px; flex-shrink: 0; }

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 32px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
  text-decoration: none;
  flex-shrink: 0;
}
.logo:hover { text-decoration: none; }
.logo-text {
  font-family: "Nova Round", var(--font-sans);
  font-weight: 400;
  font-size: 27px;
  line-height: 1;
  letter-spacing: 0;
  /* "palt" feature kerning is bad on display fonts */
  font-feature-settings: normal;
}
.footer-logo > span {
  font-family: "Nova Round", var(--font-sans);
  font-weight: 400;
  font-size: 25px;
  line-height: 1;
  letter-spacing: 0;
  font-feature-settings: normal;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  flex: 1;
}
.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 8px 12px;
  color: var(--text-muted);
  font-size: 14px;
  font-weight: 500;
  border-radius: 8px;
  background: transparent;
  border: none;
  text-decoration: none;
  transition: all 0.15s ease;
}
.nav-link:hover { color: var(--text); background: var(--bg-muted); text-decoration: none; }
.nav-link svg { opacity: 0.6; }

.nav-dropdown { position: relative; }
.nav-dropdown-menu {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  min-width: 340px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  padding: 8px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 2px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-4px);
  transition: all 0.18s ease;
}
/* Two-column layout on desktop — the chart list is long enough that splitting
   it lets the user scan everything at a glance without scrolling. */
@media (min-width: 768px) {
  .nav-dropdown-menu {
    grid-template-columns: 1fr 1fr;
    min-width: 560px;
    gap: 2px 6px;
  }
}
.nav-dropdown.is-open .nav-dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.nav-dropdown-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 10px 12px;
  border-radius: 8px;
  text-decoration: none;
  color: var(--text);
  transition: background 0.15s ease;
}
.nav-dropdown-item:hover { background: var(--bg-soft); text-decoration: none; }
.nav-dropdown-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: var(--primary-soft);
  color: var(--primary);
  flex-shrink: 0;
}
.nav-dropdown-text { display: flex; flex-direction: column; gap: 2px; }
.nav-dropdown-title { font-weight: 600; font-size: 14px; }
.nav-dropdown-desc { font-size: 12px; color: var(--text-muted); }

.header-actions { display: flex; align-items: center; gap: 8px; }
.menu-toggle {
  display: none;
  background: transparent;
  border: none;
  padding: 8px;
  border-radius: 8px;
  color: var(--text);
}
.menu-toggle:hover { background: var(--bg-muted); }

.mobile-menu {
  display: none;
  padding: 8px 16px 24px;
  border-top: 1px solid var(--border);
  background: #fff;
  max-height: calc(100vh - var(--header-h));
  overflow-y: auto;
}
.mobile-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 8px;
  color: var(--text);
  font-weight: 500;
  text-decoration: none;
  border-bottom: 1px solid var(--border);
}
.mobile-link:hover { color: var(--primary); text-decoration: none; }
.mobile-link-sub { padding-left: 16px; font-weight: 400; color: var(--text-muted); }
.mobile-section-title {
  padding: 16px 8px 8px;
  font-size: 11px;
  font-weight: 700;
  color: var(--text-soft);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.mobile-link-icon {
  display: inline-flex;
  width: 28px;
  height: 28px;
  align-items: center;
  justify-content: center;
  border-radius: 6px;
  background: var(--bg-muted);
  color: var(--primary);
}

@media (max-width: 900px) {
  .header-nav, .header-actions { display: none; }
  .menu-toggle { display: flex; margin-left: auto; }
  .mobile-menu:not([hidden]) { display: block; }
}

/* ===== Breadcrumb ===== */
.breadcrumb {
  border-bottom: 1px solid var(--border);
  background: var(--bg-soft);
}
.breadcrumb-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 14px 24px;
}
.breadcrumb-list {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 13px;
}
.breadcrumb-item a { color: var(--text-muted); text-decoration: none; }
.breadcrumb-item a:hover { color: var(--primary); text-decoration: underline; }
.breadcrumb-item [aria-current="page"] { color: var(--text); font-weight: 600; }
.breadcrumb-sep { color: var(--text-soft); }
@media (max-width: 640px) { .breadcrumb-inner { padding: 12px 16px; } }

/* ===== Sidebar ===== */
.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
}
.sidebar-sticky {
  position: sticky;
  top: calc(var(--header-h) + 16px);
}
.sidebar-header {
  padding: 8px 0 16px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 16px;
}
.sidebar-label {
  font-size: 11px;
  font-weight: 700;
  color: var(--text-soft);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}
.sidebar-category { margin-bottom: 24px; }
.sidebar-cat-title {
  font-size: 11px;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 8px;
  padding: 0 8px;
}
.sidebar-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 2px; }
.sidebar-link {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 10px;
  border-radius: 8px;
  color: var(--text);
  text-decoration: none;
  transition: background 0.15s ease;
  border: 1px solid transparent;
}
.sidebar-link:hover { background: var(--bg-soft); text-decoration: none; }
.sidebar-link.is-active {
  background: var(--primary-soft);
  border-color: #c9daff;
}
.sidebar-link.is-active .sidebar-icon { color: var(--primary); }
.sidebar-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 6px;
  background: var(--bg-muted);
  color: var(--text-muted);
  flex-shrink: 0;
}
.sidebar-link.is-active .sidebar-icon { background: #fff; color: var(--primary); }
.sidebar-text { display: flex; flex-direction: column; gap: 1px; flex: 1; min-width: 0; }
.sidebar-title-row { display: flex; align-items: center; gap: 8px; justify-content: space-between; }
.sidebar-title { font-weight: 600; font-size: 13px; }
.sidebar-desc { font-size: 11.5px; color: var(--text-muted); line-height: 1.4; }
.sidebar-badge {
  display: inline-block;
  padding: 1px 6px;
  font-size: 10px;
  font-weight: 700;
  background: var(--primary);
  color: #fff;
  border-radius: 4px;
  letter-spacing: 0.04em;
}
.sidebar-home-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 8px;
  border-top: 1px solid var(--border);
  margin-top: 8px;
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 500;
  text-decoration: none;
}
.sidebar-home-link:hover { color: var(--primary); text-decoration: none; }

/* ===== Footer ===== */
.site-footer {
  background: #0b1220;
  color: #c2cad7;
  margin-top: 0;
}
.footer-top { padding: 56px 0 32px; }
.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 1.4fr 2fr 1fr;
  gap: 48px;
}
.footer-brand { padding-right: 24px; }
.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-weight: 700;
  font-size: 16px;
  margin-bottom: 12px;
}
.footer-tagline { font-size: 13.5px; color: #8f9baf; line-height: 1.7; margin-bottom: 16px; }
.footer-tagline-sub { color: #6b7687; }
.footer-badges { display: flex; flex-wrap: wrap; gap: 8px; }
.footer-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 999px;
  font-size: 11.5px;
  color: #c2cad7;
}
.footer-title {
  font-size: 12px;
  font-weight: 700;
  color: #fff;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 16px;
}
.footer-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 10px; }
.footer-list-2col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 28px;
}
.footer-list a { color: #8f9baf; font-size: 13.5px; text-decoration: none; }
.footer-list a:hover { color: #fff; text-decoration: none; }
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding: 20px 0;
}
.footer-bottom-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 12px;
  color: #6b7687;
}
.footer-meta { font-family: var(--font-mono); letter-spacing: 0.02em; }
.footer-meta-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 8px;
  font-size: 11.5px;
  color: #6b7687;
}
.footer-meta-links a {
  color: #8f9baf;
  text-decoration: none;
  transition: color 0.15s ease;
}
.footer-meta-links a:hover { color: #fff; }
.footer-meta-sep { color: #3a4253; user-select: none; }
@media (max-width: 900px) {
  .footer-inner { grid-template-columns: 1fr 1fr; gap: 32px; }
  .footer-brand { grid-column: 1 / -1; padding-right: 0; }
  .footer-col-wide { grid-column: 1 / -1; }
}
@media (max-width: 560px) {
  .footer-inner { grid-template-columns: 1fr; gap: 32px; }
  .footer-list-2col { grid-template-columns: 1fr; }
  .footer-top { padding: 40px 0 24px; }
}

/* ===== Layout: sidebar + content ===== */
.layout {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 32px 24px 64px;
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  gap: 48px;
}
.layout-content { min-width: 0; }
@media (max-width: 1024px) {
  .layout { grid-template-columns: 1fr; gap: 24px; }
  .sidebar { display: none; }
}
@media (max-width: 640px) {
  .layout { padding: 20px 16px 48px; }
}

/* ===== Cards / Sections ===== */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
}
.section { padding: 64px 0; }
.section-sm { padding: 40px 0; }
.eyebrow {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--primary);
  margin-bottom: 12px;
}

/* ===== Utility ===== */
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap; border: 0;
}
.muted { color: var(--text-muted); }

/* ===== Toast ===== */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--text);
  color: #fff;
  padding: 12px 20px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  pointer-events: none;
  transition: all 0.25s ease;
  z-index: 1000;
  display: flex;
  align-items: center;
  gap: 8px;
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}
.toast svg { width: 16px; height: 16px; color: var(--accent); }

/* ============================================================
   Accessibility additions
   ============================================================ */

/* スクリーンリーダー専用テキスト */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* スキップリンク：Tabキーで最初に到達できる「メインコンテンツへ」リンク */
.skip-link {
  position: absolute;
  top: 0;
  left: 12px;
  z-index: 10000;
  padding: 10px 16px;
  background: var(--primary);
  color: #fff;
  text-decoration: none;
  border-radius: 0 0 var(--radius) var(--radius);
  font-weight: 600;
  font-size: 14px;
  transform: translateY(-110%);
  transition: transform 0.2s;
}
.skip-link:focus {
  transform: translateY(0);
  outline: 2px solid #fff;
  outline-offset: 2px;
}

/* グローバル :focus-visible：キーボード操作時のフォーカスを明示 */
*:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  border-radius: 4px;
}
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline-offset: 0;
}
/* マウスクリックなど非キーボード操作時はフォーカスリング非表示（ブラウザ既定挙動） */

/* モバイルメニュー内 CTA */
.mobile-cta {
  margin: 16px 12px 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  width: calc(100% - 24px);
}

/* Light-mode lock — this site does not implement a dark theme.
   When the OS prefers dark, browsers may auto-darken form controls,
   which would clash with the site's light palette. We pin
   color-scheme to light to keep things consistent. */
@media (prefers-color-scheme: dark) {
  html { color-scheme: light; }
}