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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #f5f7fa;
  color: #333;
  font-size: 16px;
}

.container {
  max-width: 700px;
  margin: 0 auto;
  padding: 16px;
}

h1 {
  font-size: 1.5rem;
  color: #4a90d9;
  text-align: center;
  padding: 16px 0 12px;
}

h2 {
  font-size: 1rem;
  color: #555;
  margin-bottom: 12px;
}

section {
  background: #fff;
  border-radius: 10px;
  padding: 16px;
  margin-bottom: 16px;
  box-shadow: 0 1px 4px rgba(0,0,0,0.08);
}

.form-group {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
}

.form-group label {
  min-width: 80px;
  font-size: 0.9rem;
  color: #666;
}

.form-group input {
  flex: 1;
  padding: 8px 10px;
  border: 1px solid #ddd;
  border-radius: 6px;
  font-size: 0.95rem;
}

.form-group input:focus {
  outline: none;
  border-color: #4a90d9;
}

.btn-primary {
  display: block;
  width: 100%;
  padding: 10px;
  background: #4a90d9;
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: 1rem;
  cursor: pointer;
  margin-top: 4px;
}

.btn-primary:hover {
  background: #357abd;
}

.chart-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}

.tab-btn {
  padding: 6px 20px;
  border: 1px solid #4a90d9;
  border-radius: 20px;
  background: #fff;
  color: #4a90d9;
  cursor: pointer;
  font-size: 0.9rem;
}

.tab-btn.active {
  background: #4a90d9;
  color: #fff;
}

#growthChart {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 6px;
  background: #f9fbfd;
}

.record-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 12px;
  border-bottom: 1px solid #f0f0f0;
  font-size: 0.9rem;
}

.record-item:last-child {
  border-bottom: none;
}

.record-info {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.record-date {
  color: #888;
  min-width: 80px;
}

.record-values {
  display: flex;
  gap: 14px;
}

.record-height {
  color: #4a90d9;
}

.record-weight {
  color: #e0804a;
}

.btn-delete {
  background: none;
  border: none;
  color: #ccc;
  cursor: pointer;
  font-size: 1.1rem;
  padding: 2px 6px;
  border-radius: 4px;
}

.btn-delete:hover {
  color: #e55;
  background: #fff0f0;
}

.empty-msg {
  color: #bbb;
  text-align: center;
  padding: 16px;
  font-size: 0.9rem;
}

@media (max-width: 480px) {
  .form-group {
    flex-direction: column;
    align-items: flex-start;
  }
  .form-group input {
    width: 100%;
  }
  .record-info {
    flex-direction: column;
    gap: 4px;
  }
}