* {
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', 'Helvetica Neue', 'Arial', sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  margin: 0;
  padding: 20px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.container {
  background: white;
  padding: 50px;
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  max-width: 600px;
  width: 100%;
}

h1 {
  color: #333;
  margin: 0 0 10px 0;
  font-size: 32px;
  font-weight: 600;
  text-align: center;
}

.subtitle {
  text-align: center;
  color: #666;
  font-size: 14px;
  margin: 0 0 30px 0;
}

.message {
  color: #666;
  font-size: 16px;
  line-height: 1.6;
  margin: 20px 0;
}

.icon {
  font-size: 60px;
  margin-bottom: 20px;
  text-align: center;
}

.button-group {
  margin-top: 30px;
  display: flex;
  justify-content: center;
}

a {
  display: inline-block;
  background-color: #667eea;
  color: white;
  padding: 12px 30px;
  text-decoration: none;
  border-radius: 4px;
  margin: 10px 5px;
  transition: background-color 0.3s;
}

a:hover {
  background-color: #764ba2;
}

/* エラーページスタイル */
.error-icon {
  color: #e74c3c;
  font-size: 80px;
  margin-bottom: 20px; 
  text-align: center;
}

.error-details {
  background-color: #fff3cd;
  border: 1px solid #ffc107;
  border-radius: 6px;
  padding: 15px;
  margin: 20px 0;
  text-align: left;
}

.error-details ul {
  margin: 0;
  padding-left: 20px;
  color: #666;
  font-size: 14px;
  line-height: 1.8;
}

/* フォームスタイル */
.form {
  width: 100%;
}

.form-group {
  margin-bottom: 25px;
  display: flex;
  flex-direction: column;
}

.form-group label {
  font-weight: 600;
  color: #333;
  margin-bottom: 8px;
  font-size: 14px;
}

.required {
  color: #e74c3c;
  margin-left: 4px;
}

.form-group input {
  padding: 12px 15px;
  border: 2px solid #e0e0e0;
  border-radius: 6px;
  font-size: 14px;
  font-family: inherit;
  transition: border-color 0.3s, box-shadow 0.3s;
}

.form-group input:focus {
  outline: none;
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-group input::placeholder {
  color: #bbb;
}

.submit-btn {
  width: 100%;
  padding: 14px;
  background-color: #667eea;
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.3s, transform 0.2s;
  margin-top: 10px;
}

.submit-btn:hover {
  background-color: #5568d3;
  transform: translateY(-2px);
}

.submit-btn:active {
  transform: translateY(0);
}