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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  color: #333;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
}

/* Header */
.header {
  background: rgba(255, 255, 255, 0.95);
  border-radius: 16px;
  padding: 20px 30px;
  margin-bottom: 20px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.1);
}

.header h1 {
  font-size: 28px;
  color: #333;
  margin-bottom: 10px;
}

.header p {
  color: #666;
  font-size: 14px;
}

/* Navigation */
.nav-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 15px;
}

.nav-tab {
  padding: 10px 20px;
  border: none;
  background: #f0f2f5;
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
  transition: all 0.3s;
}

.nav-tab:hover {
  background: #e4e6e9;
}

.nav-tab.active {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
}

/* Main Content */
.main-content {
  background: rgba(255, 255, 255, 0.95);
  border-radius: 16px;
  padding: 30px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.1);
}

.activity-title {
  font-size: 24px;
  color: #333;
  margin-bottom: 20px;
  padding-bottom: 10px;
  border-bottom: 3px solid #667eea;
}

/* Buttons */
.btn {
  padding: 12px 24px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  transition: all 0.3s;
}

.btn-primary {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-success {
  background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
  color: white;
}

.btn-warning {
  background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  color: white;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Activity 1: Password */
.password-tester {
  background: #f8f9fa;
  padding: 20px;
  border-radius: 12px;
  margin-bottom: 20px;
}

.password-input {
  width: 100%;
  padding: 15px;
  font-size: 18px;
  border: 2px solid #ddd;
  border-radius: 8px;
  margin-bottom: 15px;
}

.password-input:focus {
  outline: none;
  border-color: #667eea;
}

.strength-meter {
  height: 10px;
  background: #e0e0e0;
  border-radius: 5px;
  overflow: hidden;
  margin-bottom: 10px;
}

.strength-fill {
  height: 100%;
  transition: all 0.3s;
}

.strength-label {
  font-weight: bold;
  font-size: 16px;
}

.question-card {
  background: #f8f9fa;
  padding: 20px;
  border-radius: 12px;
  margin-bottom: 15px;
}

.question-text {
  font-size: 16px;
  margin-bottom: 15px;
  font-weight: 500;
}

.answer-options {
  display: flex;
  gap: 20px;
}

.answer-option {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
}

.answer-option input {
  width: 20px;
  height: 20px;
}

.explanation {
  background: #e3f2fd;
  padding: 15px;
  border-radius: 8px;
  margin-top: 15px;
  border-left: 4px solid #2196f3;
}

/* Activity 2: Malware */
.scenario-card {
  background: linear-gradient(135deg, #ffecd2 0%, #fcb69f 100%);
  padding: 20px;
  border-radius: 12px;
  margin-bottom: 20px;
}

.scenario-title {
  font-size: 18px;
  font-weight: bold;
  margin-bottom: 10px;
  color: #333;
}

.scenario-description {
  background: rgba(255,255,255,0.7);
  padding: 15px;
  border-radius: 8px;
  margin-bottom: 15px;
}

.option-btn {
  display: block;
  width: 100%;
  padding: 15px;
  margin-bottom: 10px;
  text-align: left;
  background: white;
  border: 2px solid #ddd;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s;
}

.option-btn:hover {
  border-color: #667eea;
  background: #f8f9ff;
}

.option-btn.selected {
  border-color: #667eea;
  background: #f0f2ff;
}

.option-btn.correct {
  border-color: #4caf50;
  background: #e8f5e9;
}

.option-btn.wrong {
  border-color: #f44336;
  background: #ffebee;
}

/* Activity 3: Leak Cases */
.leak-case {
  background: #f8f9fa;
  padding: 20px;
  border-radius: 12px;
  margin-bottom: 20px;
}

.leak-case h3 {
  color: #667eea;
  margin-bottom: 10px;
}

.case-select {
  width: 100%;
  padding: 12px;
  border: 2px solid #ddd;
  border-radius: 8px;
  margin: 10px 0;
  font-size: 14px;
}

.measures-input {
  width: 100%;
  padding: 12px;
  border: 2px solid #ddd;
  border-radius: 8px;
  min-height: 80px;
  resize: vertical;
  font-size: 14px;
}

/* Activity 4: Emergency */
.emergency-steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 15px;
  margin-bottom: 20px;
}

.step-card {
  background: #f8f9fa;
  padding: 15px;
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.3s;
  border: 2px solid transparent;
}

.step-card:hover {
  border-color: #667eea;
}

.step-card.selected {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
}

.step-card.selected .step-number {
  background: rgba(255,255,255,0.3);
}

.step-number {
  display: inline-block;
  width: 30px;
  height: 30px;
  background: #667eea;
  color: white;
  border-radius: 50%;
  text-align: center;
  line-height: 30px;
  margin-right: 10px;
  font-weight: bold;
}

.simulation-area {
  background: #1a1a2e;
  color: #00ff00;
  padding: 30px;
  border-radius: 12px;
  margin: 20px 0;
  font-family: 'Courier New', monospace;
  min-height: 200px;
}

.simulation-line {
  margin: 10px 0;
  opacity: 0;
  animation: fadeIn 0.5s forwards;
}

@keyframes fadeIn {
  to { opacity: 1; }
}

/* Activity 5: Proposal */
.suggestion-list {
  margin-bottom: 20px;
}

.suggestion-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px;
  background: #f8f9fa;
  border-radius: 8px;
  margin-bottom: 10px;
}

.suggestion-item input[type="checkbox"] {
  width: 20px;
  height: 20px;
}

.proposal-preview {
  background: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
  padding: 40px;
  border-radius: 12px;
  margin: 20px 0;
  min-height: 400px;
}

.proposal-content {
  background: white;
  padding: 40px;
  border-radius: 8px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.proposal-content h2 {
  text-align: center;
  margin-bottom: 30px;
  color: #333;
}

.proposal-content ol {
  margin: 20px 0;
  padding-left: 30px;
  line-height: 2;
}

.proposal-content li {
  margin-bottom: 10px;
}

/* Certificate */
.certificate-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0,0,0,0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.certificate {
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
  padding: 60px;
  border-radius: 20px;
  text-align: center;
  max-width: 600px;
  width: 90%;
  box-shadow: 0 20px 60px rgba(0,0,0,0.3);
  border: 10px solid #667eea;
}

.certificate h2 {
  font-size: 36px;
  color: #667eea;
  margin-bottom: 20px;
}

.certificate h3 {
  font-size: 28px;
  color: #333;
  margin: 30px 0;
}

.certificate-badge {
  font-size: 80px;
  margin: 20px 0;
}

/* Teacher Console */
.teacher-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 15px;
  margin-bottom: 30px;
}

.stats-card {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 20px;
  border-radius: 12px;
  text-align: center;
}

.stats-card h3 {
  font-size: 14px;
  margin-bottom: 10px;
  opacity: 0.9;
}

.stats-number {
  font-size: 36px;
  font-weight: bold;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
}

.data-table th,
.data-table td {
  padding: 12px;
  text-align: left;
  border-bottom: 1px solid #e0e0e0;
}

.data-table th {
  background: #f8f9fa;
  font-weight: 600;
}

.status-badge {
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 12px;
}

.status-completed {
  background: #d4edda;
  color: #155724;
}

.status-pending {
  background: #fff3cd;
  color: #856404;
}

/* Home */
.home-content {
  text-align: center;
}

.home-content h2 {
  font-size: 32px;
  margin-bottom: 20px;
  color: #333;
}

.activity-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
  margin: 30px 0;
}

.activity-card {
  background: #f8f9fa;
  padding: 25px;
  border-radius: 12px;
  transition: all 0.3s;
  cursor: pointer;
}

.activity-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.activity-card h3 {
  color: #667eea;
  margin-bottom: 10px;
}

.resources-section {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 30px;
  border-radius: 12px;
  margin-top: 30px;
}

.resources-section a {
  color: #ffd700;
  text-decoration: none;
  font-weight: 500;
}

.resources-section a:hover {
  text-decoration: underline;
}

/* Progress Bar */
.progress-bar {
  background: #e0e0e0;
  border-radius: 10px;
  height: 20px;
  margin: 10px 0;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  transition: width 0.5s;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 12px;
}

/* Responsive */
@media (max-width: 768px) {
  .container {
    padding: 10px;
  }
  
  .nav-tabs {
    overflow-x: auto;
    flex-wrap: nowrap;
  }
  
  .header h1 {
    font-size: 20px;
  }
  
  .activity-title {
    font-size: 20px;
  }
}