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

body {
  font-family: system-ui, sans-serif;
  background-color: #f6f8fa;
  color: #111;
  padding: 40px 20px;
}

.app-container {
  background: #ffffff;
  padding: 32px;
  border-radius: 16px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
  max-width: 500px;
  width: 100%;
  margin: 0 auto;
}

h1 {
  text-align: center;
  font-weight: 700;
  font-size: 1.5rem;
  margin-bottom: 24px;
}

.info-box {
  background: #eef6ff;
  border-left: 4px solid #007bff;
  padding: 12px 16px;
  font-size: 0.95rem;
  margin-bottom: 20px;
  border-radius: 8px;
}

label {
  font-weight: 600;
  margin-bottom: 8px;
  display: block;
}

input[type="number"],
select {
  width: 100%;
  padding: 10px;
  margin-bottom: 16px;
  font-size: 1rem;
  border-radius: 8px;
  border: 1px solid #ccc;
}

select optgroup {
  font-weight: bold;
  color: #444;
  background-color: #f0f0f0;
  padding: 4px 6px;
}

select optgroup + optgroup::before {
  content: "";
  display: block;
  height: 8px;
}

button {
  width: 100%;
  background-color: #007bff;
  color: white;
  padding: 12px;
  font-size: 1rem;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  margin-bottom: 10px;
  transition: transform 0.2s ease;
}

button:hover {
  background-color: #0056b3;
  transform: scale(1.02);
}

.clear-btn {
  background-color: #999;
}

.clear-btn:hover {
  background-color: #666;
}

#result {
  margin-top: 24px;
  background: #f0fdf4;
  padding: 16px;
  border-radius: 10px;
  line-height: 1.6;
  display: none;
  opacity: 0;
  transform: translateY(10px);
  transition: all 0.4s ease;
}

#result.show {
  display: block;
  opacity: 1;
  transform: translateY(0);
}

.section-title {
  font-weight: 600;
  text-decoration: underline;
  margin-top: 16px;
}