/* === Teacher Screen === */
.teacher-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.5rem;
  background: var(--surface);
  border-bottom: none;
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 100;
}
.header-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}
.teacher-logo {
  font-family: var(--font);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: -0.02em;
}
.header-actions {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

/* Class Manager */
.class-manager {
  display: flex;
  align-items: center;
  gap: 0.3rem;
}
.class-manager select {
  padding: 0.35rem 0.5rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 0.85rem;
  font-weight: 600;
  background: var(--surface);
  color: var(--text);
  min-width: 80px;
}
.class-manager .btn {
  padding: 0.3rem;
  min-width: 28px;
  height: 28px;
}

/* Roster Actions */
.roster-actions {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  flex-wrap: wrap;
}

/* Group Options */
.group-options-top {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 0.5rem;
}
.group-mode-toggle {
  display: flex;
  gap: 4px;
  background: var(--bg);
  border-radius: 8px;
  padding: 2px;
}
.group-mode-toggle .btn {
  font-size: 0.75rem;
  padding: 0.3rem 0.6rem;
  border-radius: 6px;
}
#group-auto-options {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}
.group-custom-toolbar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}

/* Group Editor (drag & drop canvas) */
.group-editor {
  margin-top: 0.25rem;
}
/* Group editor in preview panel */
.preview-panel .group-editor {
  width: 100%;
}
.group-editor-canvas {
  position: relative;
  width: 100%;
  min-height: 400px;
  max-height: 70vh;
  overflow: auto;
  background: var(--surface);
  background-image:
    radial-gradient(circle, var(--border) 1px, transparent 1px);
  background-size: 10px 10px;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  cursor: default;
}
.group-editor-canvas .group-block {
  position: absolute;
  border: 2px solid var(--primary);
  border-radius: 8px;
  padding: 4px;
  background: var(--bg);
  cursor: grab;
  user-select: none;
  transition: box-shadow 0.15s;
  z-index: 1;
}
.group-editor-canvas .group-block:hover {
  box-shadow: var(--shadow-md);
  z-index: 2;
}
.group-editor-canvas .group-block.dragging {
  cursor: grabbing;
  box-shadow: 0 4px 16px rgba(0,0,0,0.15);
  z-index: 10;
  opacity: 0.9;
}
.group-editor-canvas .group-block .group-block-label {
  text-align: center;
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 2px;
  pointer-events: none;
}
.group-editor-canvas .group-block .group-block-seats {
  display: grid;
  gap: 2px;
  pointer-events: none;
}
.group-editor-canvas .group-block .group-mini-seat {
  width: 44px;
  height: 30px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.7rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-light);
}

.teacher-layout {
  display: grid;
  grid-template-columns: 380px 1fr;
  gap: 1.25rem;
  padding: 1.25rem;
  max-width: 1400px;
  margin: 0 auto;
}

/* === Settings Panel === */
.settings-panel {
  max-height: calc(100vh - 80px);
  overflow-y: auto;
  padding-right: 0.5rem;
}
.settings-panel::-webkit-scrollbar { width: 4px; }
.settings-panel::-webkit-scrollbar-track { background: transparent; }
.settings-panel::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 2px;
}
.settings-panel::-webkit-scrollbar-thumb:hover {
  background: var(--text-light);
}

/* Layout Tabs */
.layout-tabs {
  display: flex;
  gap: 4px;
  margin-bottom: 0.75rem;
  background: var(--bg);
  border-radius: 12px;
  padding: 4px;
}
.tab {
  flex: 1;
  padding: 0.5rem 0.5rem;
  border: none;
  background: transparent;
  border-radius: 10px;
  font-family: var(--font);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, color 0.2s, box-shadow 0.2s;
  color: var(--text-light);
}
.tab.active {
  background: var(--primary);
  color: white;
  box-shadow: var(--shadow);
}
.tab:hover:not(.active) {
  background: var(--surface);
  color: var(--text);
}
.tab:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: -2px;
}

/* Layout Options */
.layout-options-wrapper {
  overflow: hidden;
}
.layout-options {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
  margin-bottom: 0.75rem;
  animation: slideDown 0.25s ease forwards;
}
.layout-options label {
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.layout-options input[type="number"] {
  width: 60px;
}

/* =========================================
   Custom Layout - Side Tools
   ========================================= */
.custom-side-tools {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.tool-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.tool-group-label {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-light);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.tool-btn-full {
  width: 100%;
  justify-content: center;
}

.tool-btn-row {
  display: flex;
  gap: 0.35rem;
}
.tool-btn-row .btn {
  flex: 1;
  justify-content: center;
  font-size: 0.72rem;
}

.tool-group-danger {
  margin-top: 0.25rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
}

/* Status bar */
.custom-status-bar {
  display: flex;
  gap: 0.75rem;
  padding: 0.5rem 0.65rem;
  background: var(--bg);
  border-radius: var(--radius-sm);
  border: none;
}
.status-item {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.78rem;
  color: var(--text-secondary);
}
.status-item strong {
  color: var(--text);
  font-weight: 700;
  font-size: 0.9rem;
}
.status-item svg {
  color: var(--text-light);
  flex-shrink: 0;
}

.custom-seat-warning {
  font-size: 0.75rem;
  padding: 0.4rem 0.6rem;
  border-radius: var(--radius-sm);
  line-height: 1.4;
}
.custom-seat-warning.warning-over {
  background: var(--danger-light);
  color: #991B1B;
  border: none;
}
.custom-seat-warning.warning-under {
  background: var(--warning-light);
  color: #92400E;
  border: none;
}
.custom-seat-warning.warning-ok {
  background: var(--success-light);
  color: #065F46;
  border: none;
}

/* =========================================
   Custom Editor
   ========================================= */
.custom-editor {
  width: 100%;
}

.custom-editor-canvas-wrap {
  position: relative;
  width: 100%;
  background: var(--surface);
  border: none;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: box-shadow 0.2s;
}
.custom-editor-canvas-wrap:hover {
  box-shadow: var(--shadow-md);
}

#custom-canvas {
  display: block;
  width: 100%;
  max-height: 500px;
  cursor: crosshair;
}
#custom-canvas:focus {
  outline: none;
}
.custom-editor-canvas-wrap:focus-within {
  box-shadow: 0 0 0 3px var(--primary-glow), var(--shadow-md);
}

/* Editor hints bar */
.custom-editor-hints {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  padding: 0.5rem 0;
  flex-wrap: wrap;
}
.editor-hint {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.7rem;
  color: var(--text-light);
}
.editor-hint kbd {
  display: inline-block;
  padding: 0.1rem 0.35rem;
  font-size: 0.65rem;
  font-family: var(--font);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* Custom preview container (for grid preview) */
.custom-preview {
  margin: 0 auto;
}

/* =========================================
   Fixed Seat / Constraint Forms
   ========================================= */
.fixed-seat-form {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  margin-bottom: 0.5rem;
}
.fixed-seat-form select {
  flex: 1;
  min-width: 120px;
}

.constraint-form {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
}
.constraint-row {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}
.constraint-row select {
  flex: 1;
  min-width: 90px;
}
.separator-icon {
  color: var(--text-light);
  font-size: 1.1rem;
  font-weight: 600;
  flex-shrink: 0;
}

/* Multi-select dropdown */
.multi-select-wrap {
  position: relative;
  flex: 1;
  min-width: 120px;
}
.multi-select-toggle {
  width: 100%;
  padding: 0.45rem 0.6rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  font-family: var(--font);
  font-size: 0.85rem;
  color: var(--text-light);
  cursor: pointer;
  text-align: left;
  transition: border-color 0.2s;
}
.multi-select-toggle:hover {
  border-color: var(--primary);
}
.multi-select-toggle.has-selection {
  color: var(--text);
  font-weight: 500;
}
.multi-select-dropdown {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  z-index: 20;
  max-height: 50vh;
  overflow-y: auto;
  background: var(--surface);
  border: none;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-md);
  margin-top: 4px;
}
.multi-select-dropdown.open {
  display: block;
}
.multi-select-item {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.6rem;
  font-size: 0.82rem;
  cursor: pointer;
  transition: background 0.15s;
}
.multi-select-item:hover {
  background: var(--bg);
}
.multi-select-item input[type="checkbox"] {
  accent-color: var(--primary);
}
.constraint-row label {
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  white-space: nowrap;
}
.constraint-row input[type="number"] {
  width: 50px;
}

/* =========================================
   Preview Panel
   ========================================= */
.preview-panel {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
  border: none;
  position: sticky;
  top: 80px;
  align-self: start;
}
.preview-actions {
  margin-top: 1rem;
  text-align: center;
}

/* Teacher seat grid sizing - fluid */
#teacher-seat-grid .seat {
  width: clamp(48px, 5vw, 68px);
  height: clamp(36px, 3.5vw, 50px);
  font-size: clamp(0.65rem, 0.8vw, 0.78rem);
}
#teacher-seat-grid .seat-pair-group .seat {
  width: clamp(44px, 4.5vw, 64px);
  height: clamp(34px, 3.2vw, 46px);
}

/* === Clickable seat guide for teacher === */
#teacher-seat-grid .seat.clickable-guide {
  animation: pulse 1.5s ease-in-out infinite;
  border-color: var(--primary);
  cursor: pointer;
}

/* =========================================
   Collapsible Card Sections (mobile)
   ========================================= */
.card-collapsible .card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
}
.card-collapsible .card-header .collapse-icon {
  transition: transform 0.2s;
  color: var(--text-light);
}
.card-collapsible.collapsed .card-header .collapse-icon {
  transform: rotate(-90deg);
}
.card-collapsible .card-body {
  overflow: hidden;
  transition: max-height 0.3s ease, opacity 0.3s ease;
  max-height: 2000px;
  opacity: 1;
}
.card-collapsible.collapsed .card-body {
  max-height: 0;
  opacity: 0;
  padding-top: 0;
  margin-top: 0;
}

/* =========================================
   Gender List
   ========================================= */
.gender-list {
  margin-top: 0.75rem;
  max-height: 240px;
  overflow-y: auto;
}
.gender-list-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}
.gender-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.3rem 0;
  font-size: 0.82rem;
  border-bottom: 1px solid var(--border);
}
.gender-row:last-child {
  border-bottom: none;
}
.gender-student-name {
  flex: 1;
  min-width: 60px;
  font-weight: 500;
}
.gender-radio {
  display: flex;
  align-items: center;
  gap: 0.2rem;
  font-size: 0.78rem;
  cursor: pointer;
  white-space: nowrap;
}
.gender-radio input[type="radio"] {
  accent-color: var(--primary);
  margin: 0;
}

/* =========================================
   Gender Rule Section
   ========================================= */
.gender-rule-options {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.gender-rule-options label {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  cursor: pointer;
}
.gender-rule-options input[type="radio"] {
  accent-color: var(--primary);
}

/* =========================================
   History Section
   ========================================= */
.history-toggle {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  cursor: pointer;
  margin-bottom: 0.5rem;
}
.history-toggle input[type="checkbox"] {
  accent-color: var(--primary);
}
.history-count-label {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.85rem;
  margin-bottom: 0.5rem;
}
.history-count-label select {
  padding: 0.25rem 0.4rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 0.85rem;
  background: var(--surface);
}
#btn-clear-history {
  margin-top: 0.5rem;
}

/* =========================================
   Responsive
   ========================================= */
/* Tablet: 2-column but narrower sidebar */
@media (max-width: 1100px) and (min-width: 769px) {
  .teacher-layout {
    grid-template-columns: 300px 1fr;
    gap: 1rem;
    padding: 1rem;
  }
}
@media (max-width: 900px) {
  .teacher-layout {
    grid-template-columns: 1fr;
  }
  .preview-panel {
    position: static;
  }
  .teacher-header {
    flex-direction: column;
    gap: 0.5rem;
    padding: 0.75rem;
  }
  .header-left {
    flex-direction: column;
    gap: 0.5rem;
  }
  .header-actions {
    flex-wrap: wrap;
    justify-content: center;
  }
  .custom-editor-hints {
    gap: 0.5rem;
  }
  /* Mobile: compact gender list */
  .gender-list {
    max-height: 180px;
  }
  .gender-row {
    padding: 0.2rem 0;
    font-size: 0.78rem;
  }
  .gender-radio {
    font-size: 0.72rem;
    gap: 0.1rem;
  }
  /* Mobile: compact cards */
  .card {
    padding: 1rem;
  }
  .settings-panel {
    max-height: none;
    padding-right: 0;
  }
}
@media (max-width: 480px) {
  .layout-tabs {
    gap: 2px;
    padding: 3px;
  }
  .tab {
    font-size: 0.72rem;
    padding: 0.4rem 0.3rem;
  }
  .teacher-layout {
    padding: 0.75rem;
    gap: 0.75rem;
  }
}