:root { 
  --bg: #0e1013; 
  --panel: #15181e; 
  --text: #e6edf3; 
  --muted: #9da9b5; 
  --accent: #6ea5ff; 
  --accent-2: #8bc8ff;
  --success: #3fb950;
  --error: #f85149;
  --warning: #d29922;
  --border: #222833;
  --hover: #1c2128;
}

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

body { 
  margin: 0; 
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  color: var(--text); 
  background: var(--bg); 
  overflow: hidden;
}

/* Header */
header { 
  display: flex; 
  flex-wrap: wrap; 
  gap: 12px; 
  align-items: center; 
  justify-content: space-between; 
  padding: 12px 20px; 
  border-bottom: 2px solid var(--border);
  background: var(--panel);
  box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

h1 { 
  margin: 0; 
  font-size: 20px;
  font-weight: 600;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.actions { 
  display: flex; 
  flex-wrap: wrap; 
  gap: 8px; 
  align-items: center; 
}

/* Buttons */
button { 
  background: var(--panel); 
  color: var(--text); 
  border: 1px solid var(--border); 
  padding: 8px 14px; 
  border-radius: 6px; 
  font-weight: 500; 
  cursor: pointer;
  font-size: 14px;
  transition: all 0.2s ease;
}

button:hover { 
  background: var(--hover);
  border-color: var(--accent);
  transform: translateY(-1px);
}

.primary-btn {
  background: var(--accent);
  color: #0a0c10;
  border: none;
  font-weight: 600;
}

.primary-btn:hover {
  background: var(--accent-2);
  box-shadow: 0 4px 12px rgba(110, 165, 255, 0.3);
}

.icon-btn {
  padding: 8px 12px;
  font-size: 16px;
}

label { 
  color: var(--muted); 
  font-size: 14px; 
  display: flex; 
  align-items: center; 
  gap: 6px;
  font-weight: 500;
}

select { 
  background: var(--panel); 
  color: var(--text); 
  border: 1px solid var(--border); 
  padding: 8px 12px; 
  border-radius: 6px;
  cursor: pointer;
  font-size: 14px;
  transition: border-color 0.2s;
}

select:hover, select:focus {
  border-color: var(--accent);
  outline: none;
}

/* Main Layout */
.layout { 
  display: grid; 
  grid-template-columns: 1fr 1fr; 
  gap: 0; 
  height: calc(100vh - 110px);
  position: relative;
}

.editor-pane, .output-pane { 
  padding: 16px;
  overflow: auto;
}

.editor-pane {
  border-right: 2px solid var(--border);
}

.editor-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
  padding: 0 4px;
}

.editor-title {
  font-weight: 600;
  color: var(--muted);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.editor-info {
  font-size: 11px;
  color: var(--muted);
}

#editor { 
  width: 100%; 
  height: calc(100% - 32px);
  background: var(--panel); 
  color: var(--text); 
  border: 1px solid var(--border); 
  border-radius: 8px; 
  font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
  font-size: 14px; 
  line-height: 1.6; 
  padding: 16px;
  resize: none;
  tab-size: 4;
}

#editor:focus {
  outline: 2px solid var(--accent);
  outline-offset: -1px;
}

/* Output */
.output-pane h3, .output-pane h4 { 
  margin: 12px 0 8px 0; 
  color: var(--muted);
  font-size: 14px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.output-head { 
  display: flex; 
  align-items: center; 
  justify-content: space-between; 
  gap: 8px;
  margin-bottom: 8px;
}

.status { 
  color: var(--success); 
  font-size: 12px;
  font-weight: 500;
}

pre { 
  margin: 0; 
  background: #0a0d12; 
  padding: 16px; 
  border-radius: 8px; 
  border: 1px solid var(--border); 
  min-height: 120px; 
  max-height: calc((100vh - 200px) / 2);
  overflow: auto;
  font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
  font-size: 13px;
  line-height: 1.5;
}

.output-content {
  color: var(--text);
}

.error-content {
  color: var(--error);
}

/* Footer */
footer { 
  padding: 12px 20px; 
  color: var(--muted); 
  border-top: 1px solid var(--border); 
  font-size: 12px;
  background: var(--panel);
  text-align: center;
}

.footer-links {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: var(--accent-2);
  text-decoration: underline;
}

/* Modal */
.modal {
  display: none;
  position: fixed;
  z-index: 1000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  overflow: auto;
  background-color: rgba(0, 0, 0, 0.8);
  animation: fadeIn 0.3s;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.modal-content {
  background-color: var(--panel);
  margin: 5% auto;
  padding: 32px;
  border: 2px solid var(--border);
  border-radius: 12px;
  width: 90%;
  max-width: 600px;
  max-height: 80vh;
  overflow-y: auto;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
  animation: slideDown 0.3s;
}

@keyframes slideDown {
  from { 
    transform: translateY(-50px);
    opacity: 0;
  }
  to { 
    transform: translateY(0);
    opacity: 1;
  }
}

.modal-content h2 {
  color: var(--text);
  margin-bottom: 16px;
  font-size: 24px;
}

.modal-content h3 {
  color: var(--accent);
  margin-top: 20px;
  margin-bottom: 12px;
  font-size: 18px;
}

.modal-content p {
  color: var(--muted);
  line-height: 1.6;
  margin-bottom: 16px;
}

.modal-content ul {
  margin-left: 24px;
  margin-bottom: 16px;
}

.modal-content li {
  color: var(--text);
  margin-bottom: 8px;
  line-height: 1.5;
}

.close-modal {
  color: var(--muted);
  float: right;
  font-size: 32px;
  font-weight: bold;
  cursor: pointer;
  line-height: 20px;
  transition: color 0.2s;
}

.close-modal:hover {
  color: var(--text);
}

.welcome-section {
  background: var(--bg);
  padding: 16px;
  border-radius: 8px;
  margin-bottom: 16px;
  border: 1px solid var(--border);
}

.shortcut-grid {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 8px 16px;
  align-items: center;
  margin-top: 12px;
}

kbd {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 4px 8px;
  font-family: monospace;
  font-size: 12px;
  color: var(--accent);
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 16px;
  color: var(--muted);
  font-size: 14px;
  cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
  cursor: pointer;
  width: 16px;
  height: 16px;
}

/* Help Panel */
.help-panel {
  position: fixed;
  right: 0;
  top: 72px;
  width: 320px;
  height: calc(100vh - 122px);
  background: var(--panel);
  border-left: 2px solid var(--border);
  box-shadow: -4px 0 12px rgba(0,0,0,0.3);
  z-index: 100;
  transition: transform 0.3s ease;
  overflow-y: auto;
}

.help-panel.collapsed {
  transform: translateX(100%);
}

.help-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--panel);
  z-index: 10;
}

.help-header h3 {
  font-size: 16px;
  color: var(--text);
  margin: 0;
}

.help-content {
  padding: 16px;
}

.help-section {
  margin-bottom: 20px;
}

.help-section h4 {
  color: var(--accent);
  font-size: 14px;
  margin-bottom: 8px;
  font-weight: 600;
}

.help-section code {
  display: block;
  background: var(--bg);
  padding: 8px 12px;
  border-radius: 4px;
  border: 1px solid var(--border);
  font-family: 'Consolas', 'Monaco', monospace;
  font-size: 12px;
  line-height: 1.5;
  color: var(--text);
  margin-bottom: 8px;
  white-space: pre;
}

/* Responsive */
@media (max-width: 1200px) {
  .help-panel {
    width: 280px;
  }
}

@media (max-width: 900px) { 
  .layout { 
    grid-template-columns: 1fr;
    height: auto;
  }
  
  .editor-pane {
    border-right: none;
    border-bottom: 2px solid var(--border);
    height: 50vh;
  }
  
  .output-pane {
    height: calc(50vh - 110px);
  }
  
  #editor { 
    height: calc(50vh - 80px);
  }
  
  .help-panel {
    width: 100%;
    top: auto;
    bottom: 0;
    height: 60vh;
    border-left: none;
    border-top: 2px solid var(--border);
  }
  
  .help-panel.collapsed {
    transform: translateY(100%);
  }

  header {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .actions {
    width: 100%;
    justify-content: flex-start;
  }
}

@media (max-width: 600px) {
  h1 {
    font-size: 18px;
  }
  
  button, select {
    font-size: 13px;
    padding: 6px 10px;
  }
  
  .modal-content {
    padding: 20px;
    margin: 10% auto;
  }
}