/* HTML Studio GitHub Desk - SaaS Design System */

:root {
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', Consolas, monospace;

  /* Color Palette - Modern Neutral Lead with Indigo/Blue Accents */
  --bg-app: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-secondary: #f1f5f9;
  --bg-surface-tertiary: #e2e8f0;

  --border-subtle: #e2e8f0;
  --border-strong: #cbd5e1;
  --border-focus: #3b82f6;

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-tertiary: #94a3b8;
  --text-on-dark: #ffffff;

  --accent-primary: #2563eb;
  --accent-primary-hover: #1d4ed8;
  --accent-subtle: #eff6ff;

  --success-bg: #f0fdf4;
  --success-border: #bbf7d0;
  --success-text: #166534;

  --warning-bg: #fffbeb;
  --warning-border: #fef3c7;
  --warning-text: #92400e;

  --danger-bg: #fef2f2;
  --danger-border: #fecaca;
  --danger-text: #991b1b;
  --danger-primary: #dc2626;
  --danger-primary-hover: #b91c1c;

  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);

  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-app);
  color: var(--text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header & Navigation */
.app-header {
  height: 60px;
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1.5rem;
  position: sticky;
  top: 0;
  z-index: 40;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 700;
  font-size: 1.1rem;
}

.brand-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, #2563eb 0%, #1e40af 100%);
  color: #fff;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 0.9rem;
  box-shadow: 0 2px 4px rgba(37, 99, 235, 0.2);
}

.brand-badge {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: var(--accent-subtle);
  color: var(--accent-primary);
  padding: 2px 8px;
  border-radius: 9999px;
  border: 1px solid rgba(37, 99, 235, 0.2);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-item {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.15s ease;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.nav-item:hover, .nav-item.active {
  color: var(--accent-primary);
}

.status-badges {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.75rem;
  font-weight: 500;
  padding: 4px 10px;
  border-radius: 9999px;
  border: 1px solid transparent;
}

.badge-success {
  background-color: var(--success-bg);
  border-color: var(--success-border);
  color: var(--success-text);
}

.badge-warning {
  background-color: var(--warning-bg);
  border-color: var(--warning-border);
  color: var(--warning-text);
}

.badge-neutral {
  background-color: var(--bg-surface-secondary);
  border-color: var(--border-subtle);
  color: var(--text-secondary);
}

.dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: currentColor;
}

/* Layout container */
.main-container {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.content-wrapper {
  max-width: 1280px;
  width: 100%;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.15s ease;
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--accent-primary);
  color: #ffffff;
}

.btn-primary:hover {
  background-color: var(--accent-primary-hover);
}

.btn-secondary {
  background-color: var(--bg-surface);
  border-color: var(--border-strong);
  color: var(--text-primary);
}

.btn-secondary:hover {
  background-color: var(--bg-surface-secondary);
  border-color: var(--text-secondary);
}

.btn-danger {
  background-color: var(--danger-primary);
  color: #ffffff;
}

.btn-danger:hover {
  background-color: var(--danger-primary-hover);
}

.btn-sm {
  padding: 0.35rem 0.75rem;
  font-size: 0.8rem;
  border-radius: var(--radius-sm);
}

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

/* Cards & Panels */
.card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.card-hover:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--border-strong);
}

/* Forms & Inputs */
.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  margin-bottom: 1.25rem;
}

.form-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
}

.form-control {
  padding: 0.6rem 0.8rem;
  font-size: 0.9rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-strong);
  background-color: var(--bg-surface);
  color: var(--text-primary);
  outline: none;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.form-control:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

/* Split Project View */
.project-view {
  display: flex;
  flex-direction: column;
  height: calc(100vh - 60px);
  overflow: hidden;
}

.project-toolbar {
  height: 52px;
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-subtle);
  padding: 0 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.project-title-area {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.project-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  overflow-x: auto;
  padding: 4px 0;
}

.split-layout {
  flex: 1;
  display: flex;
  overflow: hidden;
}

.tree-sidebar {
  width: 260px;
  background-color: var(--bg-surface);
  border-right: 1px solid var(--border-subtle);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
}

.sidebar-header {
  padding: 0.8rem 1rem;
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.file-tree {
  flex: 1;
  overflow-y: auto;
  padding: 0.5rem;
}

.tree-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.45rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  color: var(--text-secondary);
  cursor: pointer;
  user-select: none;
  margin-bottom: 2px;
  transition: background-color 0.15s ease, color 0.15s ease;
}

.tree-item:hover {
  background-color: var(--bg-surface-secondary);
  color: var(--text-primary);
}

.tree-item.active {
  background-color: var(--accent-subtle);
  color: var(--accent-primary);
  font-weight: 600;
}

.tree-item-actions {
  display: none;
  gap: 0.3rem;
}

.tree-item:hover .tree-item-actions {
  display: flex;
}

.editor-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  background-color: #1e1e2e;
  border-right: 1px solid var(--border-subtle);
  position: relative;
}

.editor-header {
  height: 40px;
  background-color: #181825;
  border-bottom: 1px solid #313244;
  padding: 0 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: #cdd6f4;
  font-size: 0.8rem;
  font-family: var(--font-mono);
}

.editor-textarea {
  flex: 1;
  width: 100%;
  background-color: #1e1e2e;
  color: #cdd6f4;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.6;
  padding: 1rem;
  border: none;
  outline: none;
  resize: none;
  tab-size: 2;
}

.preview-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  background-color: #ffffff;
}

.preview-header {
  height: 40px;
  background-color: var(--bg-surface-secondary);
  border-bottom: 1px solid var(--border-subtle);
  padding: 0 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.preview-iframe {
  flex: 1;
  width: 100%;
  height: 100%;
  border: none;
  background-color: #ffffff;
}

/* Conflict Banner */
.conflict-banner {
  background-color: var(--warning-bg);
  border-bottom: 1px solid var(--warning-border);
  color: var(--warning-text);
  padding: 0.6rem 1rem;
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* AI Explanation Drawer / Panel */
.ai-panel {
  background-color: var(--bg-surface);
  border-top: 2px solid var(--accent-primary);
  padding: 1.25rem 1.5rem;
  max-height: 280px;
  overflow-y: auto;
  box-shadow: 0 -4px 12px rgba(0,0,0,0.05);
}

.ai-panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.75rem;
}

.ai-output-text {
  font-size: 0.875rem;
  color: var(--text-primary);
  line-height: 1.6;
  white-space: pre-wrap;
}

/* Modal Overlay */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(15, 23, 42, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 1rem;
  backdrop-filter: blur(2px);
}

.modal {
  background-color: var(--bg-surface);
  border-radius: var(--radius-xl);
  max-width: 540px;
  width: 100%;
  padding: 1.75rem;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-subtle);
  max-height: 90vh;
  overflow-y: auto;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.25rem;
}

.modal-title {
  font-size: 1.15rem;
  font-weight: 700;
}

/* Empty States */
.empty-state {
  text-align: center;
  padding: 3rem 1.5rem;
  background: var(--bg-surface);
  border: 2px dashed var(--border-subtle);
  border-radius: var(--radius-lg);
}

.empty-icon {
  font-size: 2.5rem;
  color: var(--text-tertiary);
  margin-bottom: 1rem;
}

.empty-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.empty-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  max-width: 400px;
  margin: 0 auto 1.5rem;
}

/* Responsive Grid */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.25rem;
}

/* Utilities */
.text-muted { color: var(--text-secondary); }
.text-sm { font-size: 0.85rem; }
.text-xs { font-size: 0.75rem; }
.font-mono { font-family: var(--font-mono); }
.d-flex { display: flex; }
.align-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.mt-2 { margin-top: 1rem; }
.mb-2 { margin-bottom: 1rem; }

@media (max-width: 900px) {
  .split-layout {
    flex-direction: column;
  }
  .tree-sidebar {
    width: 100%;
    height: 180px;
  }
  .editor-area {
    height: 350px;
  }
  .preview-area {
    height: 350px;
  }
}