* {
  margin: 0;
  padding: 0;
}

body {
  background-color: #f1f2f3;

}

.container {
  box-sizing: border-box;
  width: 100%;
  max-width: 1600px;
  min-width: 1240px;
  margin: 20px auto;
  color: #333;
}

.container *{
  box-sizing: border-box;
}

header {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  margin-bottom: 25px;
}

header h1 {
  font-size: 2.2rem;
  margin-bottom: 5px;
}

header .subtitle {
  font-size: 1.1rem;
  opacity: 0.9;
  max-width: 95%;
  margin: 0 auto;
  line-height: 1.6;
}


.calculator-card {
  background-color: white;
  border-radius: 20px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
  padding: 20px;
  margin-bottom: 25px;
}

.input-section {
  flex: 1;
  min-width: 400px;
}

.result-section {
  flex: 1;
  margin-top: 20px;
  display: none;
  opacity: 0;
  transition: opacity 0.5s ease;
}

.result-section.visible {
  display: block;
  opacity: 1;
}

.section-title {
  font-size: 1.4rem;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.input-group {
  display: flex;
  align-items: center;
  gap: 30px;
}

.container label {
  display: block;
  font-size: 1.1rem;
  color: #555;
  font-weight: 500;
}

.container input[type="number"] {
  width: 310px;
  padding: 13.25px 15px;
  border: 2px solid #e0e0e0;
  border-radius: 12px;
  font-size: 1.1rem;
  transition: border-color 0.3s;
}

.container input[type="number"]:focus {
  outline: none;
  border-color: #4a6fa5;
  box-shadow: 0 0 0 3px rgba(74, 111, 165, 0.1);
}

.buttons {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.btn {
  padding: 14px 28px;
  border: none;
  border-radius: 12px;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 8px;
}

.btn-primary {
  background-color: #4a6fa5;
  color: white;
  flex: 1;
}

.btn-primary:hover {
  background-color: #3a5a8a;
  transform: translateY(-2px);
}

.btn-secondary {
  background-color: #e8f0fe;
  color: #4a6fa5;
  flex: 1;
}

.btn-secondary:hover {
  background-color: #d5e3fc;
}

.result-box {
  background-color: #f9fafb;
  border-radius: 15px;
  padding: 15px;
  margin-bottom: 20px;
  border: 1px solid #ddd;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.03);
}

.result-title, .stage-title {
  font-size: 1.1rem;
  margin-bottom: 15px;
  color: #4a6fa5;
  display: flex;
  align-items: center;
  gap: 10px;
}

.result-content {
  font-size: 1.2rem;
  font-weight: 600;
  color: #333;
  line-height: 1.6;
}

.stage-info {
  background: linear-gradient(135deg, #f5f7fa, #e4edf9);
  border-radius: 15px;
  padding: 15px;
  margin-bottom: 20px;
  border: 1px solid #ddd;
}

.advice-section {
  margin-top: 30px;
}

.advice-title {
  font-size: 1.1rem;
  color: #4a6fa5;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.advice-list {
  list-style-type: none;
  padding-left: 20px;
}

.advice-list li {
  margin-top: 10px;
  padding-left: 35px;
  position: relative;
  font-size: 1rem;
  line-height: 1.6;
}

.advice-list li::before {
  content: "🐾";
  position: absolute;
  left: 0;
  top: 2px;
}

.source-section {
  background-color: white;
  border-radius: 20px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
  padding: 20px;
  margin-bottom: 25px;
}

.source-content {
  display: flex;
  flex-wrap: wrap;
  gap: 30px;
}

.age-table {
  flex: 1;
  min-width: 350px;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 20px;
}

th,
td {
  border: 1px solid #e0e0e0;
  padding: 15px;
  text-align: left;
}

th {
  background-color: #f0f7ff;
  font-weight: 600;
  color: #4a6fa5;
}

tr:nth-child(even) {
  background-color: #f9fafb;
}

.feature-section {
  flex: 1;
  min-width: 350px;
}

.feature-title {
  font-size: 1.4rem;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.feature-list {
  list-style-type: none;
}

.feature-list li {
  margin-top: 15px;
  padding-left: 4px;
  position: relative;
  font-size: 1rem;
  line-height: 1.6;
}

footer {
  text-align: center;
  color: #777;
  font-size: 0.9rem;
  width: 100%;
}

.notice {
  position: fixed;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%);
  background-color: #4a6fa5;
  color: white;
  padding: 15px 35px;
  border-radius: 50px;
  font-size: 1.1rem;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  z-index: 1000;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.notice.show {
  opacity: 1;
}