body {
  margin: 0;
  padding: 0;
  background-color: #FFFFFF;
  color: #000000;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 3rem 1rem;
  background: #fff;
}

h1 {
  font-size: 2.5rem;
  font-weight: bold;
  margin-top: 0;
  margin-bottom: 0.5rem;
  color: #000000;
  text-align: center;
}

h2 {
  font-size: 1.2rem;
  font-weight: 400;
  color: #666666;
  text-align: center;
  margin-bottom: 2rem;
}

.section {
  margin-bottom: 2rem;
}

.input-section {
  background: #fafafa;
  padding: 25px;
  border-radius: 8px;
  border: 1px solid #e0e0e0;
  margin-bottom: 30px;
}

.input-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
  flex-wrap: wrap;
  gap: 10px;
}

.input-label {
  font-weight: 600;
  color: #000000;
  font-size: 1.05em;
}

#tleInput {
  width: 100%;
  resize: vertical;
  font-family: 'Courier New', monospace;
  white-space: pre;
  font-size: 0.95em;
  padding: 15px;
  border: 2px solid #ddd;
  border-radius: 6px;
  transition: border-color 0.3s;
  background: #fff;
  margin: 0;
  box-sizing: border-box;
  min-height: 80px;
}

#tleInput:focus {
  outline: none;
  border-color: #000;
}

.button-group {
  display: flex;
  gap: 10px;
  margin-top: 15px;
  flex-wrap: wrap;
}

.btn-primary, .btn-secondary {
  padding: 10px 20px;
  border: none;
  border-radius: 6px;
  font-size: 0.95em;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: 'Poppins', sans-serif;
}

.btn-primary {
  background: #000;
  color: white;
}

.btn-primary:hover {
  background: #333;
}

.btn-primary:active {
  transform: scale(0.98);
}

.btn-secondary {
  background: #fff;
  color: #000;
  border: 2px solid #ddd;
}

.btn-secondary:hover {
  background: #f5f5f5;
  border-color: #999;
}

.btn-icon {
  font-size: 1.1em;
}

.error-message {
  margin-top: 15px;
  padding: 12px 16px;
  background: #fee;
  color: #c33;
  border-left: 4px solid #c33;
  border-radius: 4px;
  display: none;
  font-weight: 500;
}

.panel {
  background: #fafafa;
  padding: 25px;
  border-radius: 8px;
  border: 1px solid #e0e0e0;
  height: 100%;
  box-sizing: border-box;
}

.section-title {
  text-align: center;
  color: #000000;
  font-size: 1.5rem;
  font-weight: bold;
  margin-top: 0;
  margin-bottom: 1.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid #eee;
}

.output {
  white-space: pre-wrap;
  background: #fff;
  padding: 20px;
  border: 2px solid #ddd;
  border-radius: 6px;
  height: calc(100% - 80px);
  min-height: 400px;
  font-family: 'Courier New', monospace;
  font-size: 0.95em;
  line-height: 1.8;
  color: #000;
  overflow-y: auto;
  box-sizing: border-box;
}

.form-group {
  display: flex;
  align-items: center;
  margin-bottom: 12px;
}

.form-group label {
  flex: 0 0 240px;
  text-align: right;
  font-weight: 500;
  margin-right: 15px;
  color: #000;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 5px;
  font-size: 0.95rem;
}

.label-text {
  display: inline-block;
}

.label-help {
  font-size: 0.85em;
  cursor: help;
  opacity: 0.5;
  transition: opacity 0.2s;
}

.label-help:hover {
  opacity: 1;
}

.form-group input,
.form-group select {
  flex: 1;
  padding: 8px 12px;
  border: 2px solid #ddd;
  border-radius: 4px;
  font-size: 0.95em;
  transition: all 0.2s;
  background: white;
  margin: 0;
  font-family: 'Poppins', sans-serif;
  box-sizing: border-box;
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: #000;
}

.form-group input[readonly] {
  background: #f5f5f5;
  color: #666;
  cursor: default;
}

.divider {
  height: 1px;
  background: #e0e0e0;
  margin: 20px 0;
}

.flex-row {
  display: flex;
  gap: 25px;
  flex-wrap: wrap;
}

.left-column {
  flex: 1;
  min-width: 300px;
}

.right-column {
  flex: 1;
  min-width: 300px;
  display: flex;
  flex-direction: column;
}

@media (max-width: 768px) {
  .flex-row {
    flex-direction: column;
  }
  
  .form-group {
    flex-direction: column;
    align-items: stretch;
  }
  
  .form-group label {
    text-align: left;
    margin-bottom: 8px;
    justify-content: flex-start;
    flex: none;
  }
  
  .button-group {
    flex-direction: column;
  }
  
  .btn-primary, .btn-secondary {
    width: 100%;
    justify-content: center;
  }
  
  h1 {
    font-size: 1.8rem;
  }
  
  h2 {
    font-size: 1rem;
  }
  
  .container {
    padding: 2rem 1rem;
  }
  
  .input-section, .panel {
    padding: 15px;
  }
  
  .output {
    min-height: 300px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 1.5rem 0.75rem;
  }
  
  .input-section, .panel {
    padding: 12px;
  }
  
  h1 {
    font-size: 1.5rem;
  }
}