/* ベース */
body {
  font-family: var(--font-base);
  color: var(--color-text);
  background-color: var(--color-surface);
  line-height: 1.7;
}

.container {
  width: 100%;
  max-width: 1060px;
  margin-inline: auto;
  padding-inline: var(--spacing-md);
}

/* ボタン */
.btn-primary {
  display: inline-block;
  background-color: var(--color-primary);
  color: var(--color-white);
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius-sm);
  text-decoration: none;
  font-weight: 700;
  transition: background-color .2s, transform .15s;
  white-space: nowrap;
}
.btn-primary:hover {
  background-color: var(--color-primary-dark);
  transform: translateY(-1px);
}

.btn-secondary {
  display: inline-block;
  background-color: transparent;
  color: var(--color-primary);
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius-sm);
  border: 2px solid var(--color-primary);
  text-decoration: none;
  font-weight: 700;
  transition: background-color .2s, color .2s, transform .15s;
  white-space: nowrap;
}
.btn-secondary:hover {
  background-color: var(--color-primary);
  color: var(--color-white);
  transform: translateY(-1px);
}

.btn-large {
  font-size: 1.0625rem;
  padding: 0.875rem 2.25rem;
}

/* セクション共通 */
section { padding-block: var(--spacing-lg); }

.section-title {
  font-size: clamp(1.375rem, 3vw, 2rem);
  font-weight: 700;
  text-align: center;
  margin-bottom: var(--spacing-md);
}

.section-lead {
  text-align: center;
  color: var(--color-subtext);
  font-size: 1rem;
  max-width: 640px;
  margin-inline: auto;
  margin-bottom: var(--spacing-md);
  line-height: 1.8;
}

/* ヘッダー */
.site-header {
  position: sticky;
  top: 0;
  background-color: var(--color-white);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
  padding-block: var(--spacing-sm);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-md);
}

.logo {
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--color-primary);
  text-decoration: none;
}

.site-nav ul {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}
.site-nav a {
  text-decoration: none;
  color: var(--color-subtext);
  font-size: 0.9375rem;
  transition: color .2s;
}
.site-nav a:hover { color: var(--color-primary); }
.site-nav .btn-header-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--color-primary);
  color: var(--color-white);
  padding: 0.625rem 1.25rem 0.625rem 1.5rem;
  border-radius: 2rem;
  font-size: 0.9375rem;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 2px 8px rgba(15,107,186,.25);
  transition: background-color .2s, transform .15s, box-shadow .2s;
}
.site-nav .btn-header-cta:hover {
  background: var(--color-primary-dark);
  color: var(--color-white);
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(15,107,186,.4);
}
.site-nav .btn-header-cta::after {
  content: "→";
  font-size: 1rem;
  line-height: 1;
  transition: transform .2s;
}
.site-nav .btn-header-cta:hover::after {
  transform: translateX(3px);
}

/* ヒーロー */
#hero {
  background: linear-gradient(135deg, #07345f 0%, #0f5f9e 50%, #0f6bba 100%);
  color: var(--color-white);
  padding-block: var(--spacing-xl);
}

.hero-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-lg);
  align-items: center;
}

.hero-eyebrow {
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: rgba(255,255,255,.55);
  margin-bottom: 0.5rem;
}

#hero h1 {
  font-size: clamp(1.625rem, 3.5vw, 2.625rem);
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 1rem;
}

.hero-sub {
  font-size: clamp(0.9375rem, 1.8vw, 1.0625rem);
  color: rgba(255,255,255,.85);
  line-height: 1.85;
  margin-bottom: 1.5rem;
}

.hero-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  background: rgba(255,255,255,.12);
  border: 1px solid rgba(255,255,255,.25);
  border-radius: 2rem;
  padding: 0.3rem 0.75rem;
  font-size: 0.8125rem;
  font-weight: 700;
  color: rgba(255,255,255,.9);
}

.hero-cta {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--spacing-sm);
}

#hero .btn-primary {
  background-color: var(--color-white);
  color: var(--color-primary);
}
#hero .btn-primary:hover { background-color: #dbeafe; }

#hero .btn-secondary {
  border-color: rgba(255,255,255,.6);
  color: var(--color-white);
}
#hero .btn-secondary:hover {
  background-color: rgba(255,255,255,.15);
  color: var(--color-white);
}

/* ヒーロー: 対話カード */
.hero-card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  box-shadow: 0 20px 60px rgba(0,0,0,.25), 0 4px 16px rgba(0,0,0,.15);
  overflow: hidden;
  color: var(--color-text);
  max-width: 460px;
  width: 100%;
  margin-inline: auto;
}

.card-header {
  background: #f1f5f9;
  border-bottom: 1px solid #e2e8f0;
  padding: 0.75rem 1rem;
  display: flex;
  align-items: center;
  gap: 0.375rem;
}

.card-dot {
  width: 0.625rem;
  height: 0.625rem;
  border-radius: 50%;
  background: #cbd5e1;
}
.card-dot:nth-child(1) { background: #fca5a5; }
.card-dot:nth-child(2) { background: #fcd34d; }
.card-dot:nth-child(3) { background: #6ee7b7; }

.card-title {
  margin-inline: auto;
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--color-subtext);
}

.card-body {
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.msg {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
}
.msg.msg-right { flex-direction: row-reverse; }

.msg-avatar {
  width: 1.75rem;
  height: 1.75rem;
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  font-size: 0.7rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.msg-bubble {
  background: #f1f5f9;
  border-radius: 1rem;
  border-bottom-left-radius: .25rem;
  padding: 0.6rem 0.875rem;
  font-size: 0.875rem;
  line-height: 1.6;
  max-width: 80%;
}
.msg.msg-right .msg-bubble {
  background: var(--color-primary);
  color: #fff;
  border-radius: 1rem;
  border-bottom-right-radius: .25rem;
}

/* 2カラムCTAカード */
#cta-cards { background: var(--color-white); padding-block: var(--spacing-lg); }

.cta-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-top: var(--spacing-md);
}

.cta-card {
  border: 2px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 2rem 1.5rem;
  text-align: center;
  transition: border-color .2s, box-shadow .2s, transform .2s;
}
.cta-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.cta-card-label {
  display: inline-block;
  background: var(--color-primary);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.2rem 0.875rem;
  border-radius: 2rem;
  margin-bottom: 1rem;
}

.cta-card h3 {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--color-text);
}

.cta-card p {
  font-size: 0.9375rem;
  color: var(--color-subtext);
  line-height: 1.7;
  margin-bottom: 1.25rem;
}

/* エンジニア向けセクション */
#for-engineer { background: var(--color-surface); }

.format-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0 1.5rem;
  font-size: 0.9375rem;
}
.format-table th, .format-table td {
  text-align: left;
  padding: 0.75rem 1rem;
  border: 1px solid var(--color-border);
}
.format-table th {
  background: var(--color-surface-alt);
  font-weight: 700;
}

/* ステップリスト（フロー） */
.step-list {
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: var(--spacing-sm);
}

.step-list li {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.step-num {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  background: var(--color-primary);
  color: #fff;
  border-radius: 50%;
  font-weight: 700;
  font-size: 0.875rem;
  flex-shrink: 0;
  margin-top: .1rem;
}

.step-list li > div strong {
  display: block;
  font-size: 0.9375rem;
  font-weight: 700;
  margin-bottom: 0.125rem;
}

.step-list li > div p {
  font-size: 0.875rem;
  color: var(--color-subtext);
  margin: 0;
}

.hint-list {
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
  margin-bottom: var(--spacing-sm);
}
.hint-list li {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  font-size: 0.9375rem;
  color: var(--color-subtext);
}
.hint-list li::before {
  content: "✓";
  color: var(--color-primary);
  font-weight: 700;
  flex-shrink: 0;
}

/* 学校向けセクション */
#for-school { background: var(--color-white); }

.theme-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0 1.5rem;
  font-size: 0.9375rem;
}
.theme-table th, .theme-table td {
  text-align: left;
  padding: 0.75rem 1rem;
  border: 1px solid var(--color-border);
}
.theme-table th {
  background: var(--color-surface-alt);
  font-weight: 700;
  width: 30%;
}

.check-list {
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
  margin-bottom: var(--spacing-sm);
}
.check-list li {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  font-size: 0.9375rem;
  color: var(--color-subtext);
}
.check-list li::before {
  content: "✓";
  color: var(--color-primary);
  font-weight: 700;
  flex-shrink: 0;
}

/* FAQ */
#faq { background: linear-gradient(180deg, #e8f0fe 0%, #f0f4f8 100%); }

.chat-faq {
  max-width: 720px;
  margin-inline: auto;
  margin-top: var(--spacing-md);
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}

.chat-exchange {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
}

.chat-q { display: flex; justify-content: flex-end; }
.chat-a { display: flex; align-items: flex-start; gap: 0.75rem; }

.chat-bubble {
  max-width: 82%;
  padding: 0.75rem 1.125rem;
  border-radius: 1.25rem;
  font-size: 0.9375rem;
  line-height: 1.7;
}

.chat-bubble-user {
  background: var(--color-primary);
  color: #fff;
  border-bottom-right-radius: .3rem;
  position: relative;
}
.chat-bubble-user::after {
  content: "";
  position: absolute;
  bottom: 0; right: -8px;
  border: 8px solid transparent;
  border-left-color: var(--color-primary);
  border-top-width: 8px;
  border-right-width: 0;
  border-bottom-width: 0;
}

.chat-bubble-bot {
  background: #fff;
  color: var(--color-text);
  border-bottom-left-radius: .3rem;
  box-shadow: 0 2px 8px rgba(0,0,0,.08);
  position: relative;
}
.chat-bubble-bot::after {
  content: "";
  position: absolute;
  bottom: 0; left: -8px;
  border: 8px solid transparent;
  border-right-color: #fff;
  border-top-width: 8px;
  border-left-width: 0;
  border-bottom-width: 0;
}

.chat-avatar {
  width: 2.25rem;
  height: 2.25rem;
  min-width: 2.25rem;
  border-radius: 50%;
  overflow: hidden;
  flex-shrink: 0;
  margin-top: .125rem;
}
.chat-avatar svg { width: 100%; height: 100%; display: block; }

/* 最終CTA */
#cta {
  background: linear-gradient(135deg, #0d2e52 0%, #0f5f9e 60%, #0f6bba 100%);
  color: var(--color-white);
  padding-block: var(--spacing-xl);
}

.cta-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-lg);
  align-items: center;
}

.cta-eyebrow {
  font-size: 0.75rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: #93c5fd;
  margin-bottom: 0.625rem;
}

#cta h2 {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
}

.cta-desc {
  font-size: 1.0625rem;
  color: rgba(255,255,255,.75);
  line-height: 1.85;
  margin-bottom: var(--spacing-md);
}

.cta-buttons {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.875rem;
  margin-bottom: var(--spacing-sm);
}

.btn-cta-main {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  background: #fff;
  color: var(--color-primary);
  padding: 1rem 2rem;
  border-radius: var(--radius-sm);
  font-size: 1.0625rem;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 4px 20px rgba(0,0,0,.3);
  transition: background .2s, transform .15s, box-shadow .2s;
}
.btn-cta-main:hover {
  background: #dbeafe;
  transform: translateY(-3px);
  box-shadow: 0 8px 32px rgba(0,0,0,.35);
}

.btn-cta-sub {
  color: rgba(255,255,255,.65);
  font-size: 0.9375rem;
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color .2s;
}
.btn-cta-sub:hover { color: rgba(255,255,255,.95); }

.cta-note {
  font-size: 0.8125rem;
  color: rgba(255,255,255,.4);
}

/* フッター */
.site-footer {
  background: var(--color-text);
  color: rgba(255,255,255,.6);
  padding-block: var(--spacing-md);
  font-size: 0.875rem;
}
.site-footer .container {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  align-items: center;
  text-align: center;
}
.site-footer nav { display: flex; gap: var(--spacing-md); }
.site-footer nav a {
  color: rgba(255,255,255,.6);
  text-decoration: none;
  transition: color .2s;
}
.site-footer nav a:hover { color: var(--color-white); }

/* フローティングCTA */
.float-cta {
  position: fixed;
  bottom: 2rem; right: 2rem;
  z-index: 300;
  transform: translateY(120%);
  opacity: 0;
  transition: transform .4s cubic-bezier(.34,1.56,.64,1), opacity .3s;
  pointer-events: none;
}
.float-cta.is-visible {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}
.float-cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--color-primary);
  color: #fff;
  padding: 0.875rem 1.5rem;
  border-radius: 3rem;
  font-size: 0.9375rem;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 4px 24px rgba(15,107,186,.5);
  transition: background .2s, transform .15s;
}
.float-cta-btn:hover {
  background: var(--color-primary-dark);
  transform: translateY(-3px);
}

/* フェードイン */
.fade-in {
  opacity: 0;
  transform: translateY(1.25rem);
  transition: opacity .6s, transform .6s;
}
.fade-in.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* アクセシビリティ */
:focus-visible {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  .fade-in { opacity: 1; transform: none; transition: none; }
  .btn-primary, .btn-secondary { transition: none; }
}

/* モバイル */
@media (max-width: 639px) {
  .site-nav { display: none; }
  .cta-grid { grid-template-columns: 1fr; }
}

/* タブレット */
@media (min-width: 640px) {
  .hero-cta { flex-direction: row; align-items: center; }
  .cta-buttons { flex-direction: row; align-items: center; }
  .site-footer .container {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}

/* デスクトップ */
@media (min-width: 1024px) {
  .hero-layout {
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
  }
  #hero { text-align: left; }
  .hero-card { margin-inline: 0; max-width: 100%; }
  .cta-inner { grid-template-columns: 1fr 1fr; }
}

/* シェアセクション */
#share { background: var(--color-bg-alt, #f8faff); }
.share-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
  margin-top: var(--spacing-md);
}
.share-card {
  background: #fff;
  border: 1px solid rgba(15,107,186,.12);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
}
.share-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: .5rem;
  color: var(--color-primary);
}
.btn-text {
  color: var(--color-primary);
  text-decoration: underline;
  font-size: .875rem;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
}
.btn-share {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .625rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: .875rem;
  font-weight: 700;
  cursor: pointer;
  border: none;
  text-decoration: none;
}
.btn-share-x { background: #000; color: #fff; }
.btn-share-copy { background: var(--color-primary); color: #fff; }
@media (min-width: 768px) {
  .share-grid { grid-template-columns: repeat(3, 1fr); }
}