:root {
  --bg: #f8fafc;
  --surface: #ffffff;
  --border: #e2e8f0;
  --line: #e2e8f0;
  --text: #1e293b;
  --ink: #1e293b;
  --heading: #1e293b;
  --text-secondary: #64748b;
  --muted: #64748b;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --accent: #2563eb;
  --accent-strong: #1d4ed8;
  --accent-bg: #eff6ff;
  --accent-soft: #eff6ff;
  --danger: #dc2626;
  --success: #16a34a;
  --warning: #f59e0b;
  --warn: #f59e0b;
  --hover: #f1f5f9;
  --panel-soft: #f8fafc;
  --mono: 'SF Mono', 'Cascadia Code', 'Consolas', monospace;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,0.1);
  --shadow-lg: 0 4px 12px rgba(0,0,0,0.15);
}

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

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

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

/* Topbar */
.topbar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;      /* 內容多時換行，不擠爆 */
  row-gap: 4px;
  gap: 12px;
  padding: 8px 16px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}

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

.brand-mark {
  width: 36px;
  height: 36px;
  background: var(--primary);
  color: white;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 14px;
}

.brand h1 {
  font-size: 16px;
  font-weight: 600;
  line-height: 1.2;
}

.brand p {
  font-size: 11px;
  color: var(--text-secondary);
}

/* Navigation */
.main-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 2px;
  margin-left: auto;
}
.main-nav .nav-link { padding: 6px 10px; font-size: 13px; white-space: nowrap; }

.nav-link {
  padding: 6px 14px;
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 500;
  transition: all 0.15s;
}

.nav-link:hover {
  background: var(--bg);
  color: var(--text);
}

.nav-link.active {
  background: var(--primary);
  color: white;
}

/* Top Actions */
.top-actions {
  display: flex;
  gap: 4px;
  align-items: center;
}

.icon-button {
  width: 32px;
  height: 32px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  color: var(--text-secondary);
  transition: all 0.15s;
}

.icon-button:hover {
  background: var(--bg);
  color: var(--text);
  border-color: var(--primary);
}

.file-button {
  width: auto;
  padding: 0 10px;
}

.file-button input[type="file"] {
  display: none;
}

/* Language Switcher */
.segmented {
  display: flex;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}

.lang-option {
  padding: 4px 10px;
  border: none;
  background: var(--surface);
  font-size: 12px;
  cursor: pointer;
  color: var(--text-secondary);
}

.lang-option.active {
  background: var(--primary);
  color: white;
}

/* Workspace */
.workspace {
  display: flex;
  flex: 1;
  overflow: hidden;
}

/* Panels */
.tool-panel {
  width: 220px;
  background: var(--surface);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  flex-shrink: 0;
}

.inspector-panel {
  width: 300px;
  background: var(--surface);
  border-left: 1px solid var(--border);
  overflow-y: auto;
  flex-shrink: 0;
}

.canvas-panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.panel-section {
  padding: 12px;
  border-bottom: 1px solid var(--border);
}

.panel-section h2 {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

/* Tool Grid */
.tool-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4px;
}

.tool-button {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 10px 8px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  cursor: pointer;
  font-size: 12px;
  color: var(--text-secondary);
  transition: all 0.15s;
}

.tool-button:hover {
  border-color: var(--primary);
  color: var(--primary);
}

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

.tool-icon {
  font-size: 18px;
}

/* Component List */
.component-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.component-button {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  border: none;
  border-radius: 6px;
  background: transparent;
  cursor: pointer;
  font-size: 12px;
  color: var(--text);
  text-align: left;
  transition: background 0.15s;
}

.component-button:hover {
  background: var(--bg);
}

/* Schematic Mini Icons */
.schematic-mini {
  width: 24px;
  height: 24px;
  border: 1px solid var(--border);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--bg);
}

.resistor-mini { background: linear-gradient(90deg, #e2e8f0 30%, transparent 30%, transparent 70%, #e2e8f0 70%); }
.source-mini { border-color: var(--primary); }
.ground-mini { border-color: #64748b; }
.switch-mini { border-color: var(--warning); }
.lamp-mini { border-color: var(--warning); background: #fef3c7; }
.led-mini { border-color: var(--danger); background: #fecaca; }
.diode-mini { border-color: var(--text-secondary); }
.capacitor-mini { border-color: var(--primary); }
.inductor-mini { border-color: #8b5cf6; }
.meter-mini { border-color: var(--success); }
.chip-mini { border-color: var(--primary); background: #dbeafe; }
.opamp-mini { border-color: var(--primary); }
.dcdc-mini { border-color: var(--warning); }

/* Template Search */
.library-search {
  width: 100%;
  padding: 6px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 12px;
  margin-bottom: 8px;
}

.template-catalog {
  max-height: 200px;
  overflow-y: auto;
}

/* Quick Help */
.compact-help p {
  font-size: 11px;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Canvas Toolbar */
.canvas-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 12px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.status-pill {
  padding: 4px 12px;
  border-radius: 20px;
  background: var(--bg);
  font-size: 12px;
  color: var(--text-secondary);
}

.canvas-actions {
  display: flex;
  gap: 4px;
}

.small-button {
  padding: 4px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface);
  font-size: 12px;
  cursor: pointer;
  color: var(--text-secondary);
  transition: all 0.15s;
}

.small-button:hover {
  background: var(--bg);
}

.small-button.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

/* Schematic Canvas */
.schematic-wrap {
  flex: 1;
  overflow: hidden;
  background: var(--bg);
}

#schematic {
  width: 100%;
  height: 100%;
}

/* Simulation Card */
.simulation-card,
.review-card {
  border-bottom: 2px solid var(--border);
}

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

.section-head h2 {
  margin-bottom: 0;
}

.sim-badge {
  padding: 2px 8px;
  border-radius: 12px;
  font-size: 10px;
  font-weight: 600;
  background: var(--bg);
  color: var(--text-secondary);
}

.sim-actions {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}

.primary-button {
  padding: 8px 16px;
  border: none;
  border-radius: 6px;
  background: var(--primary);
  color: white;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s;
}

.primary-button:hover {
  background: var(--primary-hover);
}

.danger-button {
  padding: 8px 16px;
  border: none;
  border-radius: 6px;
  background: var(--danger);
  color: white;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
}

/* Summary Grid */
.summary-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-bottom: 8px;
}

.summary-card {
  padding: 10px;
  border-radius: 6px;
  background: var(--bg);
  text-align: center;
}

.summary-card .value {
  font-size: 18px;
  font-weight: 600;
  color: var(--primary);
}

.summary-card .label {
  font-size: 10px;
  color: var(--text-secondary);
}

/* Review Upload */
.review-upload-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-bottom: 12px;
}

.drop-field {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 12px;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  text-align: center;
  cursor: pointer;
  font-size: 12px;
  color: var(--text-secondary);
  transition: border-color 0.15s;
}

.drop-field:hover {
  border-color: var(--primary);
}

.drop-field input[type="file"] {
  display: none;
}

/* PDF Parse */
.pdf-parse-section {
  margin-bottom: 12px;
}

.pdf-parse-result {
  margin-top: 8px;
  padding: 10px;
  border-radius: 6px;
  background: var(--bg);
  font-size: 12px;
}

/* Review Notes */
.review-notes {
  display: block;
  margin-bottom: 12px;
}

.review-notes span {
  display: block;
  font-size: 12px;
  color: var(--text-secondary);
  margin-bottom: 4px;
}

.review-notes textarea {
  width: 100%;
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 12px;
  resize: vertical;
  font-family: inherit;
}

.review-files {
  margin-bottom: 8px;
}

.review-report {
  font-size: 12px;
  line-height: 1.6;
}

/* Inspector */
.inspector-form {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.inspector-form label {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.inspector-form label span {
  font-size: 11px;
  color: var(--text-secondary);
}

.inspector-form input,
.inspector-form select {
  padding: 6px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 13px;
}

.switch-row {
  flex-direction: row !important;
  align-items: center;
  gap: 8px !important;
}

.inspector-actions {
  display: flex;
  gap: 8px;
  margin-top: 4px;
}

.empty-state {
  padding: 20px;
  text-align: center;
  color: var(--text-secondary);
  font-size: 13px;
}

/* Readings Table */
.table-wrap {
  overflow-x: auto;
}

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

th, td {
  padding: 6px 8px;
  border: 1px solid var(--border);
  text-align: left;
}

th {
  background: var(--bg);
  font-weight: 600;
  color: var(--text-secondary);
}

/* IC Detail */
.ic-detail-section {
  border-top: 2px solid var(--border);
}

.ic-detail-content {
  font-size: 12px;
  line-height: 1.6;
}

/* Modal */
.modal {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.modal[hidden] {
  display: none;
}

.modal-content {
  background: var(--surface);
  border-radius: 12px;
  width: 90%;
  max-width: 600px;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
}

.modal-header h2 {
  font-size: 16px;
}

.modal-body {
  padding: 20px;
}

/* IC Form */
.ic-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.ic-form label {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.ic-form label span {
  font-size: 11px;
  color: var(--text-secondary);
}

.ic-form input,
.ic-form select,
.ic-form textarea {
  padding: 6px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 13px;
}

.pins-section {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px;
}

.pins-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  max-height: 200px;
  overflow-y: auto;
}

.pin-row {
  display: grid;
  grid-template-columns: 60px 1fr 80px;
  gap: 8px;
  align-items: center;
}

.pin-row input {
  padding: 4px 8px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 12px;
}

.form-actions {
  display: flex;
  gap: 8px;
  justify-content: flex-end;
  margin-top: 8px;
}

/* Toast */
#toastHost {
  position: fixed;
  bottom: 20px;
  right: 20px;
  z-index: 2000;
}

.toast {
  padding: 10px 20px;
  border-radius: 8px;
  background: #1e293b;
  color: white;
  font-size: 13px;
  margin-top: 8px;
  animation: slideIn 0.3s ease;
}

@keyframes slideIn {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

.note {
  font-size: 11px;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-secondary); }


/* ===== 捲動統一 =====
   內容頁（知識庫/面試/IC 庫/條款…）整頁可捲動；
   全高編輯器頁（線路圖/PCB 檢視器/架構圖）body 加 class="editor-lock" 維持固定高度。 */
body:not(.editor-lock) { height: auto; min-height: 100vh; overflow-y: auto; }
body:not(.editor-lock) .app-shell { height: auto; min-height: 100vh; }


/* ===== 平移方向盤（畫布右下角浮動；點一下移動、長按連續移動） ===== */
.pan-pad {
  position: absolute; right: 14px; bottom: 14px; z-index: 6;
  display: grid; grid-template-columns: repeat(3, 34px); grid-template-rows: repeat(3, 34px);
  gap: 4px; opacity: 0.92;
}
.pan-pad .pan-btn {
  width: 34px; height: 34px; padding: 0;
  border: 1px solid #cbd5e1; background: rgba(255, 255, 255, 0.95);
  border-radius: 8px; cursor: pointer; font-size: 13px; color: #334155;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
  display: flex; align-items: center; justify-content: center;
  user-select: none; -webkit-user-select: none; touch-action: none;
}
.pan-pad .pan-btn:hover { background: #eff4ff; border-color: #2563eb; color: #1d4ed8; }
.pan-pad .pan-btn:active { background: #dbe6ff; transform: scale(0.94); }
.pan-up { grid-column: 2; grid-row: 1; }
.pan-left { grid-column: 1; grid-row: 2; }
.pan-fit { grid-column: 2; grid-row: 2; font-size: 15px; }
.pan-right { grid-column: 3; grid-row: 2; }
.pan-down { grid-column: 2; grid-row: 3; }