* {
  margin: 0;
  padding: 0;
}

body {
  background-color: #f1f2f3;

}

.container {
  box-sizing: border-box;
  width: 100%;
  max-width: 1540px;
  min-width: 1240px;
  margin: 20px auto;
  color: #333;
}

.container *{
   box-sizing: border-box;
}

header {
  text-align: center;
  padding-bottom: 20px;
  padding-top: 10px;
}

h1 {
  font-size: 2.4rem;
  margin-bottom: 10px;
  color: #2c3e50;
}

.subtitle {
  font-size: 1rem;
  color: #7f8c8d;
  max-width: 90%;
  margin: 0 auto;
  line-height: 1.6;
}

.main-content {
  display: flex;
  gap: 20px;
  margin-bottom: 30px;
}

.panel {
  flex: 1;
  background: white;
  border-radius: 12px;
  box-shadow: 0 5px 25px rgba(0, 0, 0, 0.08);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.panel-header {
  color: #333;
  padding: 15px 20px;
  font-size: 1.2rem;
  font-weight: 600;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid #dddd;
}

#input-status, #output-status{
  font-size: 1rem;
  color: #666;
  font-weight: normal;
}

.panel-actions {
  padding: 15px;
  background: #f8f9fa;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  border-bottom: 1px solid #eee;
}

.btn {
  padding: 10px 18px;
  border: none;
  border-radius: 6px;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  gap: 8px;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-validate {
  background: #2ecc71;
  color: white;
}

.btn-compress {
  background: #e74c3c;
  color: white;
}

.btn-example {
  background: #f39c12;
  color: white;
}

.btn-copy {
  background: #9b59b6;
  color: white;
}

.btn-clear {
  background: #95a5a6;
  color: white;
}

.btn-help {
  background: transparent;
  border: 2px solid #3498db;
  color: #3498db;
}

.textarea-container {
  flex: 1;
  position: relative;
  overflow: hidden;
}

.container textarea {
  width: 100%;
  height: 100%;
  padding: 20px;
  border: none;
  resize: none;
  font-family: 'Consolas', 'Monaco', monospace;
  font-size: 1.1rem;
  line-height: 1.6;
  outline: none;
  background: #fcfcfc;
}

.container textarea:focus {
  background: #fff;
}

#input {
  min-height: 540px;
  border-bottom: 1px solid #eee;
}

#output {
  min-height: 400px;
  background: #f9f9f9;
}

.info-panel {
  background: white;
  border-radius: 12px;
  box-shadow: 0 5px 25px rgba(0, 0, 0, 0.08);
  padding: 25px;
  margin-top: 20px;
}

.info-panel h2 {
  color: #2c3e50;
  margin-bottom: 20px;
  padding-bottom: 10px;
  border-bottom: 2px solid #3498db;
  font-size: 1.3rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 25px;
}

.feature-card {
  background: #f8fafc;
  border-radius: 10px;
  padding: 20px;
  border-left: 4px solid #3498db;
  box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
}

.feature-card h3 {
  margin-bottom: 12px;
  color: #2c3e50;
  font-size: 1.3rem;
  display: flex;
  align-items: center;
  gap: 10px;
}

.feature-card ul {
  padding-left: 20px;
  color: #34495e;
  line-height: 1.7;
}

.feature-card li {
  margin-bottom: 8px;
}

.status-bar {
  padding: 12px 20px;
  background: #f8f9fa;
  border-top: 1px solid #eee;
  font-size: 0.95rem;
  display: flex;
  justify-content: space-between;
  color: #7f8c8d;
}

.error {
  color: #e74c3c !important;
  font-weight: 600 !important;
}

.success {
  color: #27ae60 !important;
  font-weight: 600 !important;
}

.char-count {
  font-weight: 600;
  color: #3498db;
}

footer {
  text-align: center;
  padding: 30px 0 20px;
  color: #7f8c8d;
  font-size: 0.95rem;
}

.help-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.5s ease;
}

.help-content.expanded {
  max-height: 500px;
}

.help-content p {
  margin-bottom: 15px;
  line-height: 1.7;
  color: #2c3e50;
}

.help-content ul {
  padding-left: 30px;
  margin-bottom: 20px;
}

.help-content li {
  margin-bottom: 10px;
  line-height: 1.6;
}

.help-content code {
  background: #f1f2f3;
  padding: 2px 6px;
  border-radius: 4px;
  font-family: monospace;
}