/* -------------------------
   ベース設定
-------------------------- */
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "ヒラギノ角ゴ ProN", "Yu Gothic", "メイリオ", sans-serif;
  background: #f5f7fb;
  color: #111827;
}

/* -------------------------
   ヒーローセクション
-------------------------- */
.hero {
  background: radial-gradient(circle at top left, #dbeafe 0, #eff6ff 40%, #f5f7fb 100%);
  border-bottom: 1px solid #e5e7eb;
}

.hero-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 40px 20px 48px;
  text-align: center;
}

.hero h1 {
  margin: 0 0 8px;
  font-size: 32px;
  letter-spacing: 0.08em;
}

.hero .subtitle {
  margin: 0 0 24px;
  font-size: 16px;
  color: #4b5563;
  line-height: 1.6;
}

.hero-button {
  display: inline-block;
  padding: 10px 24px;
  font-size: 15px;
  font-weight: 600;
  color: #ffffff;
  background: #2563eb;
  border-radius: 999px;
  text-decoration: none;
  box-shadow: 0 10px 25px rgba(37, 99, 235, 0.35);
  transition: background 0.15s ease, transform 0.05s ease, box-shadow 0.15s ease;
}

.hero-button:hover {
  background: #1d4ed8;
  transform: translateY(1px);
  box-shadow: 0 6px 18px rgba(37, 99, 235, 0.28);
}

.hero-button:active {
  transform: translateY(2px);
  box-shadow: 0 3px 10px rgba(37, 99, 235, 0.2);
}

/* -------------------------
   シミュレーター一覧
-------------------------- */
.simulators {
  max-width: 960px;
  margin: 32px auto 24px;
  padding: 0 20px;
}

.simulators h2 {
  font-size: 20px;
  margin: 0 0 16px;
}

.simulator-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.sim-card {
  display: block;
  padding: 14px 14px 12px;
  background: #ffffff;
  border-radius: 12px;
  border: 1px solid #e5e7eb;
  text-decoration: none;
  color: inherit;
  box-shadow: 0 10px 24px rgba(15, 23, 42, 0.06);
  transition: transform 0.1s ease, box-shadow 0.15s ease, border-color 0.15s ease,
    background 0.15s ease;
}

.sim-card h3 {
  margin: 0 0 4px;
  font-size: 15px;
  font-weight: 600;
  color: #111827;
}

.sim-card p {
  margin: 0;
  font-size: 13px;
  color: #6b7280;
  line-height: 1.5;
}

.sim-card:hover {
  transform: translateY(-1px);
  border-color: #bfdbfe;
  box-shadow: 0 14px 30px rgba(15, 23, 42, 0.08);
  background: #f9fafb;
}

/* -------------------------
   サイト説明（SEO用テキスト）
-------------------------- */
.about {
  max-width: 960px;
  margin: 32px auto 40px;
  padding: 20px;
  border-radius: 12px;
  background: #ffffff;
  border: 1px solid #e5e7eb;
  box-shadow: 0 10px 28px rgba(15, 23, 42, 0.05);
}

.about h2 {
  font-size: 18px;
  margin: 0 0 10px;
}

.about p {
  margin: 0;
  font-size: 14px;
  color: #4b5563;
  line-height: 1.8;
}

/* -------------------------
   フッター
-------------------------- */
.footer {
  border-top: 1px solid #e5e7eb;
  padding: 12px 20px 16px;
  text-align: center;
  font-size: 12px;
  color: #9ca3af;
}

/* -------------------------
   レスポンシブ
-------------------------- */
@media (max-width: 768px) {
  .hero-inner {
    padding: 28px 16px 34px;
  }

  .hero h1 {
    font-size: 26px;
  }

  .hero .subtitle {
    font-size: 14px;
  }

  .simulator-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 520px) {
  .simulator-grid {
    grid-template-columns: 1fr;
  }

  .sim-card {
    padding: 12px 12px 10px;
  }
}