:root {
  --blue-700: #1d4ed8;
  --blue-600: #2563eb;
  --blue-50: #eff6ff;
  --blue-100: #dbeafe;
  --gray-900: #111827;
  --gray-700: #374151;
  --gray-500: #6b7280;
  --gray-300: #d1d5db;
  --gray-200: #e5e7eb;
  --gray-100: #f3f4f6;
  --bg: #f7f8fa;
  --white: #ffffff;
  --radius: 10px;
  --shadow: 0 1px 3px rgba(17, 24, 39, 0.08);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Yu Gothic UI", "Meiryo", system-ui, sans-serif;
  color: var(--gray-900);
  background: var(--bg);
  line-height: 1.7;
  font-size: 15px;
}

.container {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.site-header {
  background: var(--white);
  border-bottom: 1px solid var(--gray-200);
  position: sticky;
  top: 0;
  z-index: 50;
}
.header-inner {
  display: flex;
  align-items: center;
  height: 60px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--gray-900);
}
.brand-logo { height: 32px; width: auto; }
.brand-text { display: flex; flex-direction: column; line-height: 1.25; }
.brand-title { font-weight: 700; font-size: 15px; }
.brand-sub { font-size: 11px; color: var(--gray-500); }

/* Hero */
.hero {
  background: linear-gradient(135deg, var(--blue-700), #1e40af);
  color: var(--white);
  padding: 48px 0 56px;
  text-align: center;
}
.hero-title { font-size: 28px; font-weight: 700; margin-bottom: 8px; }
.hero-lead { font-size: 14px; opacity: 0.9; margin-bottom: 28px; }
.search-box {
  position: relative;
  max-width: 560px;
  margin: 0 auto;
}
.search-icon {
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  width: 20px;
  height: 20px;
  color: var(--gray-500);
  pointer-events: none;
}
#search-input {
  width: 100%;
  padding: 14px 18px 14px 48px;
  border: none;
  border-radius: 999px;
  font-size: 15px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
  outline: none;
}
#search-input:focus { box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25); }

/* Layout */
.main-layout {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 32px;
  padding-top: 36px;
  padding-bottom: 56px;
  align-items: start;
}

/* Category nav */
.category-nav {
  position: sticky;
  top: 76px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.category-nav a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 12px;
  border-radius: 8px;
  text-decoration: none;
  color: var(--gray-700);
  font-size: 14px;
  transition: background 0.15s;
}
.category-nav a:hover { background: var(--gray-100); }
.category-nav a.active {
  background: var(--blue-50);
  color: var(--blue-700);
  font-weight: 600;
}
.category-nav .count {
  margin-left: auto;
  font-size: 11px;
  color: var(--gray-500);
  background: var(--gray-100);
  border-radius: 999px;
  padding: 1px 7px;
}

/* FAQ content */
.category-section { margin-bottom: 36px; scroll-margin-top: 76px; }
.category-heading {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 14px;
}

.faq-item {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  margin-bottom: 10px;
  box-shadow: var(--shadow);
  overflow: hidden;
  scroll-margin-top: 130px;
}
.faq-item.highlight { border-color: var(--blue-600); box-shadow: 0 0 0 2px var(--blue-100); }

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 15px 18px;
  background: none;
  border: none;
  cursor: pointer;
  font: inherit;
  font-size: 15px;
  font-weight: 600;
  color: var(--gray-900);
  text-align: left;
}
.faq-question:hover { background: var(--gray-100); }
.faq-question .q-mark {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--blue-50);
  color: var(--blue-700);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 700;
}
.faq-question .chevron {
  margin-left: auto;
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  color: var(--gray-500);
  transition: transform 0.2s;
}
.faq-item.open .chevron { transform: rotate(180deg); }

.faq-answer {
  display: none;
  padding: 4px 18px 18px 54px;
  color: var(--gray-700);
  font-size: 14px;
}
.faq-item.open .faq-answer { display: block; }
.faq-answer p { margin-bottom: 10px; }
.faq-answer p:last-child { margin-bottom: 0; }
.faq-answer ul, .faq-answer ol { padding-left: 20px; margin-bottom: 10px; }
.faq-answer li { margin-bottom: 4px; }
.faq-answer strong { color: var(--gray-900); }

.copy-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-top: 10px;
  font-size: 12px;
  color: var(--gray-500);
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
}
.copy-link:hover { color: var(--blue-700); }

mark {
  background: #fef08a;
  border-radius: 2px;
  padding: 0 1px;
}

.no-results {
  text-align: center;
  color: var(--gray-500);
  padding: 48px 0;
}
.loading { color: var(--gray-500); }

/* Contact CTA */
.contact-cta {
  background: var(--white);
  border-top: 1px solid var(--gray-200);
  padding: 40px 0;
  text-align: center;
}
.contact-cta h2 { font-size: 18px; margin-bottom: 8px; }
.contact-cta p { color: var(--gray-500); font-size: 14px; }

/* Footer */
.site-footer {
  background: var(--gray-900);
  color: var(--gray-300);
  padding: 20px 0;
  text-align: center;
  font-size: 12px;
}

/* Mobile */
@media (max-width: 768px) {
  .main-layout {
    grid-template-columns: 1fr;
    gap: 20px;
    padding-top: 24px;
  }
  .category-nav {
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
    gap: 8px;
  }
  .category-nav a {
    border: 1px solid var(--gray-200);
    background: var(--white);
    border-radius: 999px;
    padding: 7px 14px;
    font-size: 13px;
  }
  .category-nav .count { display: none; }
  .hero { padding: 32px 0 40px; }
  .hero-title { font-size: 22px; }
  .faq-answer { padding-left: 18px; }
}