:root {
  --bg: #f4f7fb;
  --panel: #ffffff;
  --panel-border: #d9e2ef;
  --text: #122033;
  --muted: #64748b;
  --primary: #0f6f85;
  --primary-dark: #0a4f60;
  --danger: #ba2f2f;
  --danger-dark: #8f2020;
  --canvas: #edf2f7;
  --shadow: 0 12px 34px rgba(15, 35, 52, 0.12);
  --radius: 14px;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

button,
input,
select,
textarea {
  font: inherit;
}

button,
.file-btn {
  border: 0;
  border-radius: 10px;
  padding: 10px 14px;
  cursor: pointer;
  font-weight: 700;
  transition: transform 0.08s ease, background 0.15s ease, box-shadow 0.15s ease;
  user-select: none;
}

button:hover,
.file-btn:hover {
  transform: translateY(-1px);
}

button:active,
.file-btn:active {
  transform: translateY(0);
}

button.primary,
.file-btn.primary {
  background: var(--primary);
  color: white;
}

button.primary:hover,
.file-btn.primary:hover {
  background: var(--primary-dark);
}

button.secondary,
.file-btn.secondary {
  background: #e7eef7;
  color: #193044;
}

button.secondary:hover,
.file-btn.secondary:hover {
  background: #d6e3f1;
}

button.danger {
  background: #ffe0e0;
  color: var(--danger);
}

button.danger:hover {
  background: #ffd1d1;
  color: var(--danger-dark);
}

button.small {
  padding: 7px 10px;
  border-radius: 8px;
  font-size: 13px;
}

button.full,
.file-btn.full {
  width: 100%;
}

button:disabled {
  opacity: 0.48;
  cursor: not-allowed;
  transform: none;
}

.app-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.topbar {
  height: 82px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 22px;
  border-bottom: 1px solid var(--panel-border);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  z-index: 5;
}

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

.brand-mark {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  font-weight: 900;
  letter-spacing: -0.05em;
  color: white;
  background: linear-gradient(135deg, #0f6f85, #12a78a);
  box-shadow: var(--shadow);
}

.brand h1 {
  margin: 0;
  font-size: 19px;
  line-height: 1.2;
}

.brand p {
  margin: 3px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.topbar-actions {
  display: flex;
  gap: 10px;
  align-items: center;
}

.workspace {
  flex: 1;
  display: grid;
  grid-template-columns: 320px minmax(480px, 1fr) 360px;
  min-height: calc(100vh - 82px);
}

.panel {
  padding: 18px;
  overflow: auto;
  background: #f7faff;
}

.left-panel {
  border-right: 1px solid var(--panel-border);
}

.right-panel {
  border-left: 1px solid var(--panel-border);
}

.panel section {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  box-shadow: 0 3px 12px rgba(15, 35, 52, 0.04);
  border-radius: var(--radius);
  padding: 14px;
  margin-bottom: 14px;
}

.panel h2 {
  font-size: 15px;
  margin: 0 0 12px;
}

.file-drop-card {
  border: 1.5px dashed #a5b7cc;
  background: #f8fbff;
  border-radius: 14px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  min-height: 118px;
  cursor: pointer;
  color: #193044;
  text-align: center;
}

.file-drop-card.drag-over {
  background: #eaf9ff;
  border-color: var(--primary);
}

.file-drop-card .icon {
  font-size: 28px;
  color: var(--primary);
}

.file-drop-card small,
.palette-item small,
.field small,
.inspector small {
  color: var(--muted);
}

.control-row {
  display: flex;
  gap: 10px;
  align-items: center;
  margin-top: 10px;
}

.control-row.two-cols {
  align-items: end;
}

.control-row.two-cols label {
  flex: 1;
}

.control-row.inline-fields input {
  width: 74px;
}

label {
  display: grid;
  gap: 6px;
  color: #34485d;
  font-size: 13px;
  font-weight: 700;
}

input,
select,
textarea {
  width: 100%;
  border: 1px solid #cbd7e6;
  border-radius: 9px;
  background: white;
  color: var(--text);
  padding: 9px 10px;
  outline: none;
}

input:focus,
select:focus,
textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(15, 111, 133, 0.12);
}

input[type="range"] {
  padding: 0;
}

.scale-box {
  margin-top: 12px;
  padding: 12px;
  border-radius: 13px;
  background: #f5f8fc;
  border: 1px solid #e2eaf4;
}

.scale-title {
  font-weight: 800;
  font-size: 13px;
  margin-bottom: 8px;
}

.scale-box button {
  margin-top: 8px;
}

.readout {
  margin-top: 10px;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 12px;
}

.tool-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.tool-btn {
  background: #eef4fb;
  color: #1c3448;
  min-height: 44px;
  padding: 9px;
  font-size: 13px;
}

.tool-btn.active {
  background: var(--primary);
  color: white;
}

.hint {
  color: var(--muted);
  font-size: 12px;
  margin-top: 10px;
  line-height: 1.45;
}

.palette {
  display: grid;
  gap: 8px;
}

.palette-item {
  display: grid;
  grid-template-columns: 38px 1fr;
  gap: 10px;
  align-items: center;
  background: #f8fbff;
  border: 1px solid #dbe6f3;
  border-radius: 12px;
  padding: 10px;
  cursor: grab;
}

.palette-item:hover {
  border-color: var(--primary);
  background: #f1fbff;
}

.palette-item:active {
  cursor: grabbing;
}

.part-icon {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: #dbe6f3;
  display: block;
  position: relative;
}

.part-icon.rail::before {
  content: "";
  position: absolute;
  left: 6px;
  right: 6px;
  top: 15px;
  height: 4px;
  border-radius: 999px;
  background: var(--primary);
}

.part-icon.pole::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 6px;
  width: 4px;
  bottom: 6px;
  border-radius: 999px;
  background: #334155;
}

.part-icon.connector::before,
.part-icon.connector::after {
  content: "";
  position: absolute;
  background: #7c3aed;
  border-radius: 999px;
}

.part-icon.connector::before {
  left: 7px;
  right: 7px;
  top: 15px;
  height: 4px;
}

.part-icon.connector::after {
  top: 7px;
  bottom: 7px;
  left: 15px;
  width: 4px;
}

.part-icon.clip::before {
  content: "";
  position: absolute;
  left: 10px;
  top: 10px;
  width: 14px;
  height: 14px;
  border: 3px solid #ef8b22;
  border-radius: 4px;
}

.part-icon.plate.square::before,
.part-icon.plate.round::before,
.part-icon.plate.adjustable::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 9px;
  width: 16px;
  height: 16px;
  border: 3px solid #475569;
}

.part-icon.plate.round::before,
.part-icon.plate.adjustable::before {
  border-radius: 50%;
}

.part-icon.plate.adjustable::after {
  content: "";
  position: absolute;
  left: 13px;
  top: 13px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--primary);
}

.canvas-area {
  display: flex;
  flex-direction: column;
  min-width: 0;
  background: var(--canvas);
}

.canvas-toolbar {
  height: 48px;
  padding: 8px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border-bottom: 1px solid var(--panel-border);
  background: #ffffff;
}

.button-group {
  display: flex;
  gap: 8px;
  align-items: center;
}

.status {
  flex: 1;
  min-width: 0;
  text-align: center;
  font-size: 13px;
  color: var(--muted);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.canvas-wrap {
  position: relative;
  flex: 1;
  min-height: 0;
  overflow: hidden;
}

canvas {
  width: 100%;
  height: 100%;
  display: block;
  background:
    linear-gradient(rgba(28, 49, 70, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(28, 49, 70, 0.04) 1px, transparent 1px),
    #edf2f7;
  background-size: 26px 26px;
  cursor: crosshair;
}

.canvas-overlay {
  position: absolute;
  left: 50%;
  top: 18px;
  transform: translateX(-50%);
  background: rgba(18, 32, 51, 0.92);
  color: white;
  border-radius: 12px;
  padding: 10px 14px;
  box-shadow: var(--shadow);
  font-size: 13px;
  pointer-events: none;
}

.hidden {
  display: none !important;
}

.inspector.empty-state {
  color: var(--muted);
  line-height: 1.5;
}

.inspector form {
  display: grid;
  gap: 10px;
}

.inspector .field-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.inspector .field-grid.three {
  grid-template-columns: repeat(3, 1fr);
}

.inspector .part-title {
  border-radius: 12px;
  padding: 10px;
  background: #f5f8fc;
  border: 1px solid #e2eaf4;
  margin-bottom: 10px;
}

.inspector .part-title strong {
  display: block;
  margin-bottom: 4px;
}

.inspector .actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-top: 4px;
}

.checkbox-row {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 13px;
  color: #34485d;
}

.checkbox-row input {
  width: auto;
}

.bom-summary {
  display: grid;
  gap: 10px;
}

.bom-summary .metric-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.metric {
  border-radius: 12px;
  background: #f5f8fc;
  border: 1px solid #e2eaf4;
  padding: 10px;
}

.metric strong {
  display: block;
  font-size: 18px;
  line-height: 1.15;
}

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

.bom-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 12px;
}

.bom-table th,
.bom-table td {
  padding: 8px 6px;
  border-bottom: 1px solid #e5edf6;
  text-align: left;
  vertical-align: top;
}

.bom-table th {
  color: #34485d;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.bom-table td:nth-child(2),
.bom-table td:nth-child(3) {
  white-space: nowrap;
}

.summary-actions {
  margin-top: 10px;
  display: grid;
  gap: 8px;
}

textarea {
  min-height: 116px;
  resize: vertical;
}

@media (max-width: 1180px) {
  .workspace {
    grid-template-columns: 290px minmax(420px, 1fr);
  }
  .right-panel {
    grid-column: 1 / -1;
    border-left: 0;
    border-top: 1px solid var(--panel-border);
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 14px;
  }
  .right-panel section {
    margin: 0;
  }
}

@media (max-width: 840px) {
  .topbar {
    height: auto;
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }
  .topbar-actions {
    flex-wrap: wrap;
  }
  .workspace {
    grid-template-columns: 1fr;
  }
  .left-panel,
  .right-panel {
    border: 0;
  }
  .right-panel {
    grid-template-columns: 1fr;
  }
  .canvas-area {
    min-height: 560px;
  }
  .canvas-toolbar {
    height: auto;
    flex-wrap: wrap;
  }
  .status {
    order: 3;
    flex-basis: 100%;
  }
}