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

body {
  font-family: 'Inter', sans-serif;
  background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
  color: #ffffff;
  min-height: 100vh;
}

.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 20px;
}

.header {
  text-align: center;
  margin-bottom: 30px;
}

.header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 10px;
  background: linear-gradient(45deg, #ff6b6b, #4ecdc4);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.header p {
  font-size: 1.1rem;
  opacity: 0.9;
  font-weight: 400;
}

.main-content {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 30px;
  margin-bottom: 40px;
}

.map-section {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 20px;
  padding: 20px;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.map-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 15px;
  flex-wrap: wrap;
  gap: 15px;
}

.control-group {
  display: flex;
  align-items: center;
  gap: 20px;
}

.btn {
  padding: 12px 24px;
  border: none;
  border-radius: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  font-size: 0.9rem;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.2);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.3);
  transform: translateY(-2px);
}

.station-counter {
  background: rgba(76, 175, 80, 0.2);
  padding: 8px 16px;
  border-radius: 20px;
  font-weight: 600;
  border: 1px solid rgba(76, 175, 80, 0.3);
}

.instruction {
  background: rgba(255, 193, 7, 0.2);
  padding: 8px 16px;
  border-radius: 12px;
  font-size: 0.9rem;
  border: 1px solid rgba(255, 193, 7, 0.3);
}

.map-container {
  height: 500px;
  border-radius: 15px;
  overflow: hidden;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
  margin-bottom: 15px;
}

.legend {
  display: flex;
  justify-content: center;
  gap: 25px;
  flex-wrap: wrap;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
}

.legend-color {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 2px solid white;
}

.legend-color.epicenter {
  background: #ff4757;
}

.legend-color.station {
  background: #3742fa;
}

.legend-color.circle {
  background: transparent;
  border: 2px solid #ffa502;
}

.info-panel {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.card {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 20px;
  padding: 25px;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.card h3 {
  margin-bottom: 20px;
  font-size: 1.3rem;
  font-weight: 600;
}

.data-container {
  space-y: 15px;
}

.station-data {
  background: rgba(255, 255, 255, 0.1);
  padding: 15px;
  border-radius: 12px;
  margin-bottom: 15px;
  border-left: 4px solid #4ecdc4;
}

.station-data h4 {
  margin-bottom: 8px;
  color: #4ecdc4;
}

.data-row {
  display: flex;
  justify-content: space-between;
  margin-bottom: 5px;
  font-size: 0.9rem;
}

.no-data {
  text-align: center;
  opacity: 0.7;
  font-style: italic;
}

.progress-container {
  display: flex;
  flex-direction: column;
  gap: 15px;
}

.progress-step {
  display: flex;
  align-items: center;
  gap: 15px;
  padding: 12px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.05);
  transition: all 0.3s ease;
}

.progress-step.active {
  background: rgba(76, 175, 80, 0.2);
  border: 1px solid rgba(76, 175, 80, 0.3);
}

.progress-step.completed {
  background: rgba(76, 175, 80, 0.3);
  border: 1px solid rgba(76, 175, 80, 0.5);
}

.step-number {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 0.9rem;
}

.progress-step.active .step-number {
  background: #4caf50;
}

.progress-step.completed .step-number {
  background: #4caf50;
}

.explanation-section {
  margin-top: 40px;
}

.explanation-card {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 20px;
  padding: 40px;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.explanation-card h2 {
  margin-bottom: 30px;
  font-size: 2rem;
  font-weight: 700;
  text-align: center;
}

.explanation-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
}

.explanation-item {
  background: rgba(255, 255, 255, 0.05);
  padding: 25px;
  border-radius: 15px;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.explanation-item h4 {
  margin-bottom: 15px;
  color: #4ecdc4;
  font-size: 1.2rem;
  font-weight: 600;
}

.explanation-item p {
  line-height: 1.6;
  margin-bottom: 15px;
  opacity: 0.9;
}

.explanation-item ul {
  margin-left: 20px;
  line-height: 1.8;
}

.explanation-item li {
  margin-bottom: 8px;
  opacity: 0.9;
}

.formula {
  background: rgba(0, 0, 0, 0.3);
  padding: 15px;
  border-radius: 8px;
  margin: 15px 0;
  font-family: 'Courier New', monospace;
  text-align: center;
}

@media (max-width: 1024px) {
  .main-content {
    grid-template-columns: 1fr;
  }
  
  .explanation-content {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .container {
    padding: 15px;
  }
  
  .header h1 {
    font-size: 2rem;
  }
  
  .map-container {
    height: 400px;
  }
  
  .map-controls {
    flex-direction: column;
    align-items: stretch;
  }
  
  .control-group {
    justify-content: center;
  }
  
  .legend {
    gap: 15px;
  }
  
  .explanation-card {
    padding: 25px;
  }
}


.legend-color.circle {
  background: #ffa502;
  border: 2px solid white;
}

.legend-color.hyperbola {
  background: transparent;
  border: 2px dashed #e74c3c;
}

/* ... (keep all existing CSS) ... */

.language-switcher {
  margin-top: 15px;
  display: flex;
  justify-content: center;
  gap: 10px;
}

.btn-lang {
  background: rgba(255, 255, 255, 0.15);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.3);
  padding: 8px 15px;
  border-radius: 8px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

.btn-lang.active {
  background: #4ecdc4; /* Or your primary accent color */
  color: #1e3c72;
  font-weight: 600;
}

.btn-lang:not(.active):hover {
  background: rgba(255, 255, 255, 0.25);
}

.map-options {
  display: flex;
  gap: 20px;
  margin-bottom: 15px;
  flex-wrap: wrap;
  justify-content: center; /* Center options if they wrap */
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  cursor: pointer;
  padding: 5px 10px;
  background-color: rgba(255,255,255,0.1);
  border-radius: 8px;
  transition: background-color 0.2s;
}
.checkbox-label:hover {
  background-color: rgba(255,255,255,0.2);
}

.checkbox-label input[type="checkbox"] {
  cursor: pointer;
}

/* Smaller font for permanent hyperbola labels if needed */
.hyperbola-permanent-label {
  background: rgba(0, 0, 0, 0.7) !important;
  border: none !important;
  border-radius: 4px !important;
  color: white !important;
  font-size: 10px !important; /* Smaller font */
  padding: 2px 5px !important;
  box-shadow: 0 1px 3px rgba(0,0,0,0.3) !important;
  white-space: nowrap;
}