:root {
  --bg: #f0f4f8;
  --panel: #ffffff;
  --panel-soft: #f8fafc;
  --border: #dbe3ef;
  --text: #1e293b;
  --muted: #64748b;
  --accent: #2563eb;
  --accent-soft: #eff6ff;
  --success: #16a34a;
  --success-soft: #dcfce7;
  --danger: #dc2626;
  --danger-soft: #fee2e2;
  --warn: #d97706;
  --shadow: 0 8px 24px rgba(15, 23, 42, 0.08);
  --radius: 10px;
  --sidebar-w: 220px;
  --rail-w: 52px;
  --right-w: 260px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

.demo-badge {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 200;
  padding: 5px 10px;
  border-radius: 8px;
  background: #0f172a;
  color: #f8fafc;
  font-size: 11px;
  font-weight: 600;
}

.demo-back {
  position: fixed;
  top: 10px;
  right: 10px;
  z-index: 200;
  padding: 6px 12px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
  text-decoration: none;
  font-size: 12px;
  box-shadow: var(--shadow);
}

.demo-back:hover { background: var(--panel-soft); }

.shell {
  display: grid;
  grid-template-rows: 48px 1fr;
  min-height: 100vh;
}

.shell-header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 16px;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
}

.shell-header h1 {
  margin: 0;
  font-size: 16px;
}

.shell-header span {
  color: var(--muted);
  font-size: 12px;
}

.shell-body {
  display: grid;
  grid-template-columns: var(--sidebar-w) var(--rail-w) 1fr;
  min-height: 0;
  height: calc(100vh - 48px);
}

.sidebar {
  border-right: 1px solid var(--border);
  background: var(--panel);
  padding: 12px;
  overflow: auto;
}

.sidebar-item {
  padding: 6px 8px;
  border-radius: 6px;
  font-size: 13px;
  color: var(--muted);
}

.sidebar-item.active {
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
}

.rail {
  border-right: 1px solid var(--border);
  background: var(--panel-soft);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 10px 6px;
}

.rail-btn {
  width: 36px;
  height: 36px;
  border: none;
  border-radius: 8px;
  background: transparent;
  cursor: pointer;
  font-size: 16px;
}

.rail-btn.active {
  background: var(--accent-soft);
}

.workspace {
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  overflow: hidden;
  background: var(--bg);
}

/* Shared doc components */
.doc-title-input {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 10px;
  font-size: 15px;
  font-weight: 600;
}

.doc-title-input:focus {
  outline: 2px solid rgba(37, 99, 235, 0.25);
  border-color: var(--accent);
}

.doc-ext {
  flex-shrink: 0;
  color: var(--muted);
  font-weight: 600;
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px;
  font-size: 12px;
  color: var(--muted);
}

.breadcrumb {
  padding: 2px 6px;
  border-radius: 6px;
  background: transparent;
  border: none;
  color: inherit;
  cursor: pointer;
  font: inherit;
}

.breadcrumb:hover { background: var(--panel-soft); color: var(--text); }

.breadcrumb.current {
  color: var(--text);
  font-weight: 600;
  cursor: default;
}

.breadcrumb-sep { opacity: 0.45; user-select: none; }

.btn {
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
  border-radius: 8px;
  padding: 7px 12px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
}

.btn:hover { background: var(--panel-soft); }

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

.btn-primary:hover { background: #1d4ed8; }

.btn-success {
  background: var(--success-soft);
  border-color: #86efac;
  color: #166534;
}

.btn-ghost {
  border-color: transparent;
  background: transparent;
}

.btn-danger {
  background: var(--danger-soft);
  border-color: #fca5a5;
  color: var(--danger);
}

.editor-textarea {
  width: 100%;
  min-height: 220px;
  flex: 1;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 13px;
  line-height: 1.55;
  resize: none;
  background: var(--panel);
}

.editor-textarea:focus {
  outline: 2px solid rgba(37, 99, 235, 0.2);
  border-color: var(--accent);
}

.yaml-textarea {
  width: 100%;
  min-height: 120px;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 12px;
  line-height: 1.5;
  resize: vertical;
  background: #fbfdff;
}

.yaml-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 6px;
}

.view-toggle {
  display: inline-flex;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}

.view-toggle button {
  border: none;
  background: var(--panel);
  padding: 6px 10px;
  font-size: 12px;
  cursor: pointer;
}

.view-toggle button.active {
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
}

.toast {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  opacity: 0;
  pointer-events: none;
  background: #0f172a;
  color: #f8fafc;
  padding: 10px 16px;
  border-radius: 999px;
  font-size: 13px;
  transition: 0.2s ease;
  z-index: 300;
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.hidden { display: none !important; }