:root {
  color-scheme: light;
  --bg: #f6f7fb;
  --panel: #ffffff;
  --border: #e3e6ef;
  --text: #1f2430;
  --muted: #5b6475;
  --accent: #3b6ef2;
  --accent-weak: #e1e9ff;
  --success: #16a34a;
  --danger: #dc2626;
  --shadow: 0 10px 30px rgba(23, 32, 67, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px 8px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

h1 {
  margin: 0 0 2px;
  font-size: 20px;
}

.subtitle {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
}

.layout {
  display: grid;
  grid-template-columns: 2.2fr 1fr;
  gap: 16px;
  padding: 8px 20px 20px;
  align-items: start;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px;
  box-shadow: var(--shadow);
  min-height: 70vh;
  overflow-y: auto;
}

.csv-panel {
  height: 90vh;
  padding: 12px;
  display: flex;
  flex-direction: column;
  position: sticky;
  top: 8px;
}

.panel-header {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 12px;
}

.csv-tabs {
  display: flex;
  gap: 4px;
  border-bottom: 2px solid var(--border);
}

.csv-tab {
  padding: 6px 12px;
  border: none;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font-size: 11px;
  font-weight: 600;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  transition: all 0.2s;
}

.csv-tab:hover {
  color: var(--text);
}

.csv-tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

h2 {
  margin: 0;
  font-size: 14px;
}

.node-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

input[type="text"] {
  flex: 1 1 26px;
  padding: 6px 8px;
  border-radius: 8px;
  border: 1px solid var(--border);
  font-size: 12px;
}

.csv-filter-input {
  width: 100%;
  padding: 4px 6px;
  border-radius: 6px;
  border: 1px solid var(--border);
  font-size: 12px;
  margin-top: 4px;
  height: 26px;
  flex: none;
}

button {
  border: none;
  background: var(--accent);
  color: white;
  border-radius: 8px;
  padding: 6px 10px;
  cursor: pointer;
  font-weight: 600;
  font-size: 12px;
  transition: all 0.2s ease;
}

button:hover {
  opacity: 0.9;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(59, 110, 242, 0.3);
}

button.secondary {
  background: var(--accent-weak);
  color: var(--accent);
}

button.secondary:hover {
  background: #d4daef;
}

button.small {
  padding: 4px 8px;
  font-size: 11px;
  border-radius: 6px;
}

button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

button.danger {
  background: #fee2e2;
  color: var(--danger);
}

button.danger:hover {
  background: #fecaca;
}

.hint {
  margin: 0;
  color: var(--muted);
  font-size: 11px;
}

.file-input {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--accent-weak);
  padding: 6px 10px;
  border-radius: 8px;
  color: var(--accent);
  font-weight: 600;
  font-size: 12px;
  cursor: pointer;
}

.file-input.secondary {
  background: #eef1f7;
  color: var(--muted);
}

.file-input input {
  display: none;
}

.tree-container ul {
  list-style: none;
  padding-left: 16px;
  margin: 4px 0;
  border-left: 1px solid #d4daef;
  padding-left: 12px;
  margin-left: 4px;
}

.tree-node {
  padding: 3px 6px;
  border-radius: 8px;
  border: 1px solid transparent;
  margin: 2px 0;
}

.node-drop {
  height: 12px;
  margin: 2px 0;
  border-radius: 4px;
}

.node-drop.active {
  background: var(--accent-weak);
  border: 2px dashed var(--accent);
  height: 16px;
}

.tree-node.drag-over {
  background: var(--accent-weak);
  border-color: var(--accent);
}

.tree-node .node-header {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
  padding: 3px 6px;
  border-radius: 6px;
  transition: background-color 0.15s;
}

.tree-node .node-header:hover {
  background-color: rgba(59, 110, 242, 0.08);
}

.tree-node .node-header button {
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s;
}

.tree-node .node-header button.always-visible {
  opacity: 1;
  pointer-events: auto;
}

.tree-node .node-header:hover button:not(.always-visible) {
  opacity: 1;
  pointer-events: auto;
}

.tree-node .node-header.selected {
  background-color: rgba(59, 110, 242, 0.12);
}

.tree-node .node-header.selected button {
  opacity: 1;
  pointer-events: auto;
}

.node-toggle {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 2px 6px;
  min-width: 24px;
}

.node-toggle.collapsed {
  color: var(--accent);
  border-color: var(--accent);
}

.node-drag {
  cursor: grab;
  padding: 4px 6px;
  border-radius: 6px;
  border: 1px dashed var(--border);
  color: var(--muted);
  background: #fafbff;
  font-size: 11px;
}

.node-title {
  font-weight: 600;
  font-size: 13px;
  cursor: grab;
  padding: 2px 4px;
  border-radius: 4px;
  transition: background-color 0.2s;
}

.node-title:active {
  cursor: grabbing;
}

.node-title.selected {
  color: var(--accent);
  background: rgba(59, 110, 242, 0.1);
}

.node-edit-input {
  border: none;
  background: transparent;
  color: var(--text);
  font-weight: 600;
  font-size: 13px;
  padding: 2px 4px;
  border-bottom: 2px solid var(--accent);
  min-width: 100px;
  outline: none;
  cursor: grab;
}

.node-items {
  margin-top: 6px;
  padding-left: 36px;
  margin-left: 4px;
  border-left: 1px dashed #d4daef;
}

.node-item {
  background: #f8f9ff;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px 8px;
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.node-item strong {
  font-size: 11px;
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.node-item span {
  font-size: 10px;
  color: var(--muted);
  flex-shrink: 0;
}

.csv-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
  overflow-y: auto;
  flex: 1;
  min-height: 0;
  padding-right: 4px;
}

.csv-item {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px 8px;
  background: #fdfdff;
  cursor: grab;
  font-size: 11px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 6px;
}

.csv-item strong {
  display: block;
  font-size: 11px;
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.csv-item span {
  font-size: 10px;
  color: var(--muted);
  flex-shrink: 0;
}

.csv-item-btn {
  padding: 3px 8px !important;
  font-size: 10px !important;
  white-space: nowrap;
}

.plan-indicator {
  font-size: 14px;
  line-height: 1;
  flex-shrink: 0;
  margin-right: 4px;
}

.plan-indicator.plan-keep {
  color: #16a34a;
}

.plan-indicator.plan-revise {
  color: #16a34a;
}

.plan-indicator.plan-combine {
  color: #3b82f6;
}

.plan-indicator.plan-delete {
  color: #dc2626;
  font-weight: bold;
}

.csv-legend {
  display: flex;
  gap: 12px;
  padding: 8px;
  margin-top: 8px;
  font-size: 11px;
  color: var(--muted);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 4px;
}

.context-menu {
  position: fixed;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  padding: 4px;
  z-index: 1000;
  min-width: 120px;
}

.context-menu-item {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 10px;
  cursor: pointer;
  border-radius: 4px;
  font-size: 12px;
  transition: background 0.15s;
}

.context-menu-item:hover {
  background: var(--accent-weak);
}

.csv-item.used {
  background: #eef1f7;
  border-color: #d4daef;
}

.empty-state {
  color: var(--muted);
  font-size: 11px;
  padding: 8px 0;
}

.remove-zone {
  border: 2px dashed var(--border);
  border-radius: 10px;
  padding: 8px;
  text-align: center;
  color: var(--muted);
  margin-bottom: 8px;
  background: #fbfbff;
  font-size: 11px;
}

.remove-zone.drag-over {
  border-color: var(--danger);
  color: var(--danger);
  background: #fff1f1;
}

.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 2000;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(4px);
}

.modal-content {
  background: var(--panel);
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
  max-width: 600px;
  width: 90%;
  max-height: 80vh;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

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

.notes-textarea {
  width: 100%;
  min-height: 200px;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-family: inherit;
  font-size: 13px;
  resize: vertical;
  outline: none;
}

.notes-textarea:focus {
  border-color: var(--accent);
}

.modal-actions {
  display: flex;
  gap: 8px;
  justify-content: flex-end;
}