body {
  font-family: "Helvetica Neue", "Arial", "Hiragino Sans", "Meiryo", sans-serif;
  margin: 0;
  background: #f8f9fa;
  color: #333;
  line-height: 1.6;
}
.tool-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 18px;
  margin-top: 20px;
}

.tool-card {
  display: block;
  background: #fff;
  border-radius: 10px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.1);
  padding: 20px;
  text-decoration: none;
  color: #333;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.tool-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 4px 10px rgba(0,0,0,0.2);
}

.tool-card h3 {
  color: #004080;
  margin-bottom: 10px;
}


/* ✅ ナビゲーションバー */
.site-nav {
  text-align: center;
  background: linear-gradient(90deg, #004080, #0066cc);
  padding: 12px 0;
}

.site-nav a {
  color: #fff;
  text-decoration: none;
  margin: 0 18px;
  font-weight: 600;
  transition: color 0.3s;
}

.site-nav a:hover {
  color: #cce6ff;
}

/* ✅ ヒーローバナー */
.hero {
  background-image: url("https://images.unsplash.com/photo-1581093588401-22f4f7d3e6b3?auto=format&fit=crop&w=1600&q=80");
  background-size: cover;
  background-position: center;
  color: white;
  text-align: center;
  padding: 80px 20px;
  position: relative;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 700px;
  margin: 0 auto;
}

.hero h1 {
  font-size: 1.8rem;
  margin-bottom: 15px;
}

.hero p {
  font-size: 1rem;
}

/* ✅ メインコンテンツ */
.container {
  display: flex;
  flex-direction: column;
  gap: 14px;
  max-width: 420px;
  margin: 30px auto;
  padding: 15px;
  background: #fff;
  border-radius: 10px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.1);
}

label {
  font-weight: 600;
  color: #222;
}

input,
select {
  width: 100%;
  padding: 8px;
  font-size: 1rem;
  border: 1px solid #ccc;
  border-radius: 6px;
  box-sizing: border-box;
}

input:focus,
select:focus {
  border-color: #0078d7;
  outline: none;
  box-shadow: 0 0 4px rgba(0,120,215,0.3);
}

button {
  padding: 12px;
  font-size: 1.1rem;
  background-color: #0078d7;
  color: white;
  border: none;
  cursor: pointer;
  border-radius: 8px;
  transition: background-color 0.3s ease;
}

button:hover {
  background-color: #005fa3;
}

#result {
  margin-top: 18px;
  font-weight: bold;
  background: #eef4ff;
  border-radius: 6px;
  padding: 15px;
  border-left: 5px solid #0078d7;
  font-size: 1rem;
}

footer {
  text-align: center;
  margin: 40px 0 20px;
  color: #555;
}

footer a {
  color: #004080;
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

@media (max-width: 600px) {
  .hero {
    padding: 60px 15px;
  }
  .hero h1 {
    font-size: 1.4rem;
  }
  .container {
    width: 90%;
    box-shadow: none;
  }
  button {
    font-size: 1rem;
    padding: 10px;
  }
}