/* DESIGN SYSTEM & VARIABLES */
:root {
  --bg-gradient: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
  --card-bg: #ffffff;
  --card-border: #e2e8f0;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --accent-color: #4f46e5;
  --accent-hover: #4338ca;
  --accent-light: #e0e7ff;
  --sidebar-bg: #ffffff;
  --sidebar-border: #e2e8f0;
  --item-hover: #f8fafc;

  --status-todo-bg: #f1f5f9;
  --status-todo-text: #475569;
  --status-todo-border: #cbd5e1;

  --status-progress-bg: #fffbeb;
  --status-progress-text: #b45309;
  --status-progress-border: #fde68a;

  --status-done-bg: #ecfdf5;
  --status-done-text: #047857;
  --status-done-border: #a7f3d0;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --glass-bg: rgba(255, 255, 255, 0.8);
  --glass-border: rgba(226, 232, 240, 0.8);
  --scrollbar-thumb: #cbd5e1;
}

/* =====================================================
   DARK MODE — "Dim" style (dễ nhìn hơn, ít tương phản)
   Phiên bản cũ (tối hơn) được giữ lại bên dưới dạng comment
   để có thể khôi phục bất cứ lúc nào.

   PHIÊN BẢN CŨ (gốc — rất tối):
     --bg-gradient: radial-gradient(circle at top left, #0f172a 0%, #020617 100%);
     --card-bg: rgba(30, 41, 59, 0.7);
     --card-border: rgba(255, 255, 255, 0.06);
     --text-main: #f8fafc;
     --text-muted: #94a3b8;
     --sidebar-bg: rgba(15, 23, 42, 0.9);
     --sidebar-border: rgba(255, 255, 255, 0.06);
     --item-hover: rgba(255, 255, 255, 0.03);
     --glass-bg: rgba(15, 23, 42, 0.6);
     --glass-border: rgba(255, 255, 255, 0.05);
     --scrollbar-thumb: #334155;
===================================================== */
html.dark {
  --bg-gradient: linear-gradient(135deg, #1e2433 0%, #1a1f2e 100%);
  --card-bg: rgba(37, 47, 70, 0.92);
  --card-border: rgba(255, 255, 255, 0.10);
  --text-main: #e2e8f0;
  --text-muted: #9eacbf;
  --accent-color: #6366f1;
  --accent-hover: #4f46e5;
  --accent-light: rgba(99, 102, 241, 0.18);
  --sidebar-bg: rgba(25, 32, 50, 0.97);
  --sidebar-border: rgba(255, 255, 255, 0.09);
  --item-hover: rgba(255, 255, 255, 0.06);

  --status-todo-bg: rgba(148, 163, 184, 0.12);
  --status-todo-text: #94a3b8;
  --status-todo-border: rgba(148, 163, 184, 0.3);

  --status-progress-bg: rgba(217, 119, 6, 0.18);
  --status-progress-text: #fbbf24;
  --status-progress-border: rgba(251, 191, 36, 0.3);

  --status-done-bg: rgba(16, 185, 129, 0.18);
  --status-done-text: #34d399;
  --status-done-border: rgba(52, 211, 153, 0.3);

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.25), 0 2px 4px -2px rgba(0, 0, 0, 0.25);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.35), 0 4px 6px -4px rgba(0, 0, 0, 0.35);
  --glass-bg: rgba(30, 40, 65, 0.78);
  --glass-border: rgba(255, 255, 255, 0.10);
  --scrollbar-thumb: #404f6d;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

body {
  font-family: 'Inter', sans-serif;
  background: var(--bg-gradient);
  color: var(--text-main);
  height: 100vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

/* SCROLLBAR STYLE */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--scrollbar-thumb);
  border-radius: 999px;
}

/* TOP HEADER BAR */
header {
  height: 70px;
  background: var(--sidebar-bg);
  border-bottom: 1px solid var(--sidebar-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  z-index: 100;
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(8px);
}

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

.logo-badge {
  background: var(--accent-color);
  color: #ffffff;
  font-family: 'Outfit', sans-serif;
  font-weight: 700;
  font-size: 16px;
  padding: 8px 12px;
  border-radius: 10px;
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.35);
  letter-spacing: 0.5px;
}

.header-title-container h1 {
  font-family: 'Outfit', sans-serif;
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.2px;
}

.header-title-container p {
  font-size: 11px;
  color: var(--text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-top: 1px;
}

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

.btn {
  padding: 8px 14px;
  font-size: 13px;
  font-weight: 500;
  border-radius: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  color: var(--text-main);
  box-shadow: var(--shadow-sm);
  transition: all 0.15s ease;
}

.btn:hover {
  background: var(--item-hover);
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

.btn.btn-view-diagram {
  text-decoration: none;
}


.theme-toggle-btn {
  width: 40px;
  height: 40px;
  padding: 0;
  justify-content: center;
  border-radius: 50%;
}

/* WORKSPACE BODY */
.workspace {
  flex: 1;
  display: flex;
  overflow: hidden;
  position: relative;
}

/* SIDEBAR */
aside {
  width: 320px;
  background: var(--sidebar-bg);
  border-right: 1px solid var(--sidebar-border);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  overflow-y: auto;
  padding: 24px 20px;
  gap: 24px;
}

.sidebar-section-title {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.search-container {
  position: relative;
}

.search-input {
  width: 100%;
  background: var(--bg-gradient);
  border: 1px solid var(--card-border);
  padding: 10px 14px 10px 36px;
  font-size: 13px;
  border-radius: 8px;
  color: var(--text-main);
  outline: none;
}

.search-input:focus {
  border-color: var(--accent-color);
  box-shadow: 0 0 0 2px var(--accent-light);
}

.search-icon-svg {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  width: 14px;
  height: 14px;
  fill: var(--text-muted);
  pointer-events: none;
}

/* FILTER CHIPS */
.filter-chips {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.filter-chip {
  padding: 10px 12px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border: 1px solid transparent;
  background: transparent;
  color: var(--text-main);
}

.filter-chip:hover {
  background: var(--item-hover);
}

.filter-chip.active {
  background: var(--accent-light);
  color: var(--accent-color);
  border-color: rgba(99, 102, 241, 0.2);
}

.chip-count {
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 999px;
  background: rgba(0, 0, 0, 0.05);
}

html.dark .chip-count {
  background: rgba(255, 255, 255, 0.08);
}

/* PROGRESS BAR IN SIDEBAR */
.progress-panel {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 16px;
  box-shadow: var(--shadow-sm);
}

.progress-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 10px;
}

.progress-header h3 {
  font-size: 14px;
  font-weight: 600;
}

.progress-pct {
  font-family: 'Outfit', sans-serif;
  font-size: 24px;
  font-weight: 700;
  color: var(--accent-color);
}

.progress-bar-container {
  width: 100%;
  height: 8px;
  background: var(--bg-gradient);
  border-radius: 999px;
  overflow: hidden;
  margin-bottom: 12px;
  border: 1px solid var(--card-border);
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-color) 0%, #818cf8 100%);
  width: 0%;
  border-radius: 999px;
  transition: width 0.4s ease-out;
}

.progress-stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  text-align: center;
}

.stat-box {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.stat-num {
  font-family: 'Outfit', sans-serif;
  font-size: 15px;
  font-weight: 600;
}

.stat-label {
  font-size: 9px;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
}

/* MAIN PANEL */
main {
  flex: 1;
  padding: 24px 32px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

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

.view-mode-selector {
  display: flex;
  background: var(--sidebar-bg);
  border: 1px solid var(--card-border);
  padding: 3px;
  border-radius: 8px;
  box-shadow: var(--shadow-sm);
}

.view-mode-btn {
  padding: 6px 12px;
  font-size: 12px;
  font-weight: 600;
  border: none;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  border-radius: 6px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.view-mode-btn.active {
  background: var(--accent-color);
  color: #ffffff;
  box-shadow: var(--shadow-sm);
}

/* TREE VIEW MODE */
.tree-container {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.module-node {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.module-header {
  padding: 16px 20px;
  background: var(--item-hover);
  border-bottom: 1px solid var(--card-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
}

.module-header-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.module-title {
  font-family: 'Outfit', sans-serif;
  font-size: 16px;
  font-weight: 600;
  color: var(--text-main);
}

.module-progress-pill {
  font-size: 11px;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 999px;
  background: var(--accent-light);
  color: var(--accent-color);
}

.module-body {
  padding: 16px 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.group-node {
  border: 1px solid var(--card-border);
  border-radius: 10px;
  overflow: hidden;
}

.group-header {
  padding: 12px 16px;
  background: rgba(0, 0, 0, 0.01);
  border-bottom: 1px solid var(--card-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
}

html.dark .group-header {
  background: rgba(255, 255, 255, 0.01);
}

.group-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

.group-body {
  padding: 10px 14px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

/* LEAF / SCREEN NODE IN TREE */
.screen-item {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.screen-main-row {
  padding: 10px 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  gap: 16px;
}

.screen-main-row:hover {
  background: var(--item-hover);
}

.screen-info-block {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 1;
}

.screen-id-badge {
  font-family: 'Outfit', sans-serif;
  font-size: 11px;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: 6px;
  background: var(--bg-gradient);
  border: 1px solid var(--card-border);
  color: var(--text-muted);
  min-width: 65px;
  text-align: center;
}

.screen-title-text {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-main);
}

.screen-edu-code {
  font-family: monospace;
  font-size: 11px;
  color: var(--text-muted);
  background: rgba(0, 0, 0, 0.03);
  padding: 2px 6px;
  border-radius: 4px;
}

html.dark .screen-edu-code {
  background: rgba(255, 255, 255, 0.05);
}

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

/* STATUS SELECT DROPDOWN */
.status-select-container {
  position: relative;
}

.status-dropdown {
  padding: 4px 20px 4px 8px;
  font-size: 11px;
  font-weight: 600;
  border-radius: 6px;
  border: 1px solid transparent;
  cursor: pointer;
  outline: none;
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%23475569'%3e%3cpath d='M7 10l5 5 5-5H7z'/%3e%3c/svg%3e");
  background-position: right 4px center;
  background-repeat: no-repeat;
  background-size: 12px;
  transition: all 0.15s ease;
}

html.dark .status-dropdown {
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='%2394a3b8'%3e%3cpath d='M7 10l5 5 5-5H7z'/%3e%3c/svg%3e");
}

.status-dropdown option {
  background-color: var(--sidebar-bg);
  color: var(--text-main);
}

.status-dropdown.todo {
  background-color: var(--status-todo-bg);
  color: var(--status-todo-text);
  border-color: var(--status-todo-border);
}

.status-dropdown.progress {
  background-color: var(--status-progress-bg);
  color: var(--status-progress-text);
  border-color: var(--status-progress-border);
}

.status-dropdown.done {
  background-color: var(--status-done-bg);
  color: var(--status-done-text);
  border-color: var(--status-done-border);
}

.chevron-icon {
  width: 16px;
  height: 16px;
  fill: var(--text-muted);
  transition: transform 0.2s ease;
}

.expanded .chevron-icon {
  transform: rotate(90deg);
}

.rotated-180 {
  transform: rotate(180deg);
}

/* EXPANDED DETAILS PANEL */
.screen-detail-panel {
  padding: 14px;
  background: var(--item-hover);
  border-top: 1px solid var(--card-border);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.details-row {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.details-label {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
}

.table-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.table-tag-link {
  font-family: monospace;
  font-size: 11px;
  font-weight: 600;
  color: var(--accent-color);
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  padding: 4px 8px;
  border-radius: 6px;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: all 0.1s ease;
  box-shadow: var(--shadow-sm);
}

.table-tag-link:hover {
  border-color: var(--accent-color);
  background: var(--accent-light);
  transform: translateY(-1px);
}

.desc-textarea {
  width: 100%;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 8px;
  padding: 10px;
  font-size: 13px;
  color: var(--text-main);
  outline: none;
  resize: vertical;
  min-height: 60px;
  font-family: inherit;
}

.desc-textarea:focus {
  border-color: var(--accent-color);
  box-shadow: 0 0 0 2px var(--accent-light);
}

.auto-save-indicator {
  align-self: flex-end;
  font-size: 11px;
  color: var(--text-muted);
  font-style: italic;
  display: flex;
  align-items: center;
  gap: 4px;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.auto-save-indicator.visible {
  opacity: 1;
}

/* CARD VIEW GRID MODE */
.card-grid-container {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.card-group-section h2 {
  font-family: 'Outfit', sans-serif;
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 12px;
  padding-bottom: 6px;
  border-bottom: 2px solid var(--card-border);
  color: var(--text-main);
}

.grid-layout {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 16px;
}

.screen-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  box-shadow: var(--shadow-sm);
  position: relative;
}

.screen-card:hover {
  box-shadow: var(--shadow-md);
  border-color: rgba(99, 102, 241, 0.2);
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.card-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-main);
  line-height: 1.4;
}

/* SVG ICONS */
.icon-svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

/* HIDDEN FILE INPUT FOR IMPORT */
#import-file-input {
  display: none;
}

/* HELPERS */
.hidden {
  display: none !important;
}

/* MODULE SELECTOR */
.module-selector-container {
  margin-left: 20px;
  position: relative;
}

#module-select {
  background: var(--sidebar-bg);
  border: 1px solid var(--card-border);
  color: var(--text-main);
  padding: 8px 32px 8px 16px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  outline: none;
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%236b7280' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 14px;
  min-width: 220px;
  box-shadow: var(--shadow-sm);
  transition: all 0.15s ease;
}

#module-select:focus {
  border-color: var(--accent-color);
  box-shadow: 0 0 0 2px var(--accent-light);
}

/* CLOUD STATUS BADGE */
.cloud-status-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border-radius: 20px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  box-shadow: var(--shadow-sm);
  border: 1px solid transparent;
}

.cloud-status-badge.offline {
  background: rgba(148, 163, 184, 0.12);
  color: var(--text-muted);
  border-color: var(--card-border);
}

.cloud-status-badge.offline .status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--text-muted);
}

.cloud-status-badge.connecting {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
  border-color: rgba(251, 191, 36, 0.2);
}

.cloud-status-badge.connecting .status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #fbbf24;
  animation: pulse 1s infinite alternate;
}

.cloud-status-badge.connected {
  background: rgba(16, 185, 129, 0.15);
  color: #34d399;
  border-color: rgba(52, 211, 153, 0.2);
}

.cloud-status-badge.connected .status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #10b981;
  box-shadow: 0 0 6px #10b981;
}

.cloud-status-badge.error {
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
  border-color: rgba(248, 113, 113, 0.2);
}

.cloud-status-badge.error .status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #ef4444;
}

/* TOAST NOTIFICATIONS */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  z-index: 20000;
  pointer-events: none;
}

.toast {
  padding: 12px 18px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 8px;
  box-shadow: var(--shadow-lg);
  pointer-events: auto;
  animation: slideIn 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  max-width: 320px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(8px);
}

.toast.info {
  background: rgba(79, 70, 229, 0.9);
  color: #ffffff;
}

.toast.success {
  background: rgba(16, 185, 129, 0.9);
  color: #ffffff;
}

.toast.error {
  background: rgba(239, 68, 68, 0.9);
  color: #ffffff;
}

@keyframes slideIn {
  from {
    transform: translateY(12px) scale(0.95);
    opacity: 0;
  }

  to {
    transform: translateY(0) scale(1);
    opacity: 1;
  }
}

@keyframes pulse {
  from {
    opacity: 0.4;
  }

  to {
    opacity: 1;
  }
}

/* ADMIN SETTINGS MODAL */
.admin-modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10000;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.admin-modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.admin-modal-card {
  background: var(--sidebar-bg);
  border: 1px solid var(--card-border);
  width: 80%;
  max-width: 1400px;
  height: 85vh;
  border-radius: 16px;
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transform: translateY(16px) scale(0.98);
  transition: transform 0.2s ease;
}

.admin-modal-overlay.active .admin-modal-card {
  transform: translateY(0) scale(1);
}

.admin-modal-header {
  padding: 16px 24px;
  border-bottom: 1px solid var(--card-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--item-hover);
}

.admin-modal-header h3 {
  font-family: 'Outfit', sans-serif;
  font-size: 16px;
  font-weight: 700;
  color: var(--text-main);
}

.close-modal-btn {
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-size: 24px;
  cursor: pointer;
  outline: none;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  transition: background 0.15s;
}

.close-modal-btn:hover {
  background: rgba(0, 0, 0, 0.05);
  color: var(--text-main);
}

.admin-modal-body {
  flex: 1;
  display: flex;
  overflow: hidden;
}

.admin-sidebar {
  width: 180px;
  border-right: 1px solid var(--card-border);
  background: var(--item-hover);
  padding: 16px 8px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.admin-tab-btn {
  padding: 10px 12px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
  border: none;
  background: transparent;
  cursor: pointer;
  border-radius: 6px;
  text-align: left;
  transition: all 0.15s ease;
}

.admin-tab-btn:hover {
  background: rgba(0, 0, 0, 0.03);
  color: var(--text-main);
}

.admin-tab-btn.active {
  background: var(--accent-color);
  color: #ffffff;
}

.admin-content-area {
  flex: 1;
  padding: 24px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.admin-panel-title {
  font-family: 'Outfit', sans-serif;
  font-size: 16px;
  font-weight: 700;
  color: var(--text-main);
  border-bottom: 2px solid var(--card-border);
  padding-bottom: 8px;
  margin-bottom: 12px;
}

.admin-input-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.admin-input-group label {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
}

.admin-input {
  width: 100%;
  padding: 8px 12px;
  border-radius: 6px;
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  color: var(--text-main);
  font-size: 13px;
  outline: none;
}

.admin-input:focus {
  border-color: var(--accent-color);
  box-shadow: 0 0 0 2px var(--accent-light);
}

.admin-btn {
  padding: 8px 14px;
  font-size: 12px;
  font-weight: 600;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition: all 0.15s ease;
}

.admin-btn.primary {
  background: var(--accent-color);
  color: white;
}

.admin-btn.primary:hover {
  background: var(--accent-hover);
}

.admin-btn.danger {
  background: rgba(239, 68, 68, 0.1);
  color: #ef4444;
  border: 1px solid rgba(239, 68, 68, 0.2);
}

.admin-btn.danger:hover {
  background: #ef4444;
  color: white;
}

.admin-btn.secondary {
  background: rgba(0, 0, 0, 0.05);
  color: var(--text-main);
}

.admin-btn.secondary:hover {
  background: rgba(0, 0, 0, 0.08);
}

.admin-list-card {
  border: 1px solid var(--card-border);
  border-radius: 8px;
  padding: 10px 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--card-bg);
}

/* =============================================
   RESPONSIVE - HAMBURGER MENU BUTTON
============================================= */
.mobile-menu-btn {
  display: none;
  width: 36px;
  height: 36px;
  padding: 0;
  justify-content: center;
  align-items: center;
  background: transparent;
  border: 1px solid var(--card-border);
  border-radius: 8px;
  cursor: pointer;
  color: var(--text-main);
  flex-shrink: 0;
}

.mobile-menu-btn:hover {
  background: var(--item-hover);
}

.mobile-menu-btn svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
}

/* Mobile overlay backdrop */
.mobile-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(2px);
  z-index: 150;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.mobile-overlay.active {
  display: block;
  opacity: 1;
}

/* =============================================
   TABLET: 769px – 1024px
============================================= */
@media (max-width: 1024px) and (min-width: 769px) {
  aside {
    width: 260px;
    padding: 18px 14px;
  }

  #module-select {
    min-width: 160px;
    font-size: 12px;
    padding: 6px 28px 6px 12px;
  }

  .cloud-status-badge .status-text {
    display: none;
  }

  .cloud-status-badge {
    padding: 6px 8px;
    border-radius: 50%;
    width: 32px;
    height: 32px;
    justify-content: center;
  }

  .grid-layout {
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  }

  .btn {
    padding: 7px 10px;
    font-size: 12px;
    gap: 5px;
  }
}

/* =============================================
   MOBILE: ≤ 768px
============================================= */
@media (max-width: 768px) {

  /* --- BODY LAYOUT --- */
  body {
    overflow: hidden;
  }

  /* --- HEADER --- */
  header {
    height: auto;
    min-height: 56px;
    padding: 10px 14px;
    flex-wrap: wrap;
    gap: 8px;
    position: relative;
    z-index: 200;
  }

  .header-left {
    gap: 8px;
    flex: 1;
    min-width: 0;
  }

  .logo-badge {
    font-size: 13px;
    padding: 6px 9px;
    flex-shrink: 0;
  }

  .header-title-container h1 {
    font-size: 13px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .header-title-container p {
    display: none;
  }

  .module-selector-container {
    display: none;
  }

  .header-right {
    gap: 6px;
    flex-wrap: wrap;
  }

  /* Hamburger button visible on mobile */
  .mobile-menu-btn {
    display: flex;
  }

  /* Cloud status: chỉ hiện dot */
  .cloud-status-badge .status-text {
    display: none;
  }

  .cloud-status-badge {
    padding: 6px 8px;
    border-radius: 50%;
    width: 32px;
    height: 32px;
    justify-content: center;
  }

  /* Ẩn text trong các button, giữ icon */
  .btn-text-label {
    display: none;
  }

  .btn {
    padding: 7px 9px;
    gap: 0;
  }

  /* Ẩn Export, Import, Reset text (chỉ icon) */
  #export-btn .btn-text-label,
  #import-btn .btn-text-label,
  #reset-btn .btn-text-label,
  #admin-settings-btn .btn-text-label {
    display: none;
  }

  /* --- SIDEBAR (mobile: fixed, slide-in) --- */
  aside {
    position: fixed;
    top: 0;
    left: -100%;
    width: 85vw;
    max-width: 320px;
    height: 100vh;
    z-index: 200;
    padding: 70px 18px 24px;
    overflow-y: auto;
    transition: left 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 4px 0 24px rgba(0, 0, 0, 0.2);
  }

  aside.mobile-open {
    left: 0;
  }

  /* --- WORKSPACE --- */
  .workspace {
    flex-direction: column;
  }

  /* --- MAIN CONTENT --- */
  main {
    padding: 16px;
    overflow-y: auto;
    height: calc(100vh - 56px);
    flex: none;
  }

  .main-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

  .view-mode-selector {
    width: 100%;
    justify-content: stretch;
  }

  .view-mode-btn {
    flex: 1;
    justify-content: center;
    font-size: 11px;
    padding: 6px 8px;
  }

  #view-title {
    font-size: 16px !important;
  }

  /* --- TREE VIEW --- */
  .module-header {
    padding: 12px 14px;
  }

  .module-title {
    font-size: 14px;
  }

  .module-body {
    padding: 12px 12px;
  }

  .group-body {
    padding: 8px 10px;
  }

  .screen-main-row {
    padding: 10px 12px;
    gap: 8px;
    flex-wrap: wrap;
  }

  .screen-info-block {
    flex-wrap: wrap;
    gap: 6px;
  }

  .screen-controls {
    gap: 8px;
    margin-left: auto;
  }

  .screen-edu-code {
    display: none;
  }

  /* --- CARD GRID --- */
  .grid-layout {
    grid-template-columns: 1fr;
  }

  /* --- ADMIN MODAL --- */
  .admin-modal-card {
    width: 95vw;
    height: 90vh;
  }

  .admin-modal-body {
    flex-direction: column;
  }

  .admin-sidebar {
    width: 100%;
    border-right: none;
    border-bottom: 1px solid var(--card-border);
    flex-direction: row;
    overflow-x: auto;
    padding: 8px;
    gap: 4px;
    flex-shrink: 0;
  }

  .admin-tab-btn {
    white-space: nowrap;
    padding: 8px 12px;
    font-size: 12px;
  }

  .admin-content-area {
    padding: 16px;
  }

  /* --- TOAST --- */
  .toast-container {
    left: 16px;
    right: 16px;
    bottom: 16px;
  }

  .toast {
    max-width: 100%;
  }

  /* --- PROGRESS PANEL --- */
  .progress-panel {
    padding: 12px;
  }

  .progress-pct {
    font-size: 20px;
  }
}

/* =============================================
   MOBILE TINY: ≤ 375px  
============================================= */
@media (max-width: 375px) {
  .logo-badge {
    display: none;
  }

  .btn {
    padding: 6px 7px;
  }
}

/* RICH TEXT NOTES PREVIEW & EDITOR STYLE */
.note-preview-box {
  border: 1px solid var(--card-border);
  padding: 8px 12px;
  border-radius: 6px;
  background: var(--bg-gradient);
  min-height: 48px;
  max-height: 100px;
  overflow-y: auto;
  font-size: 13px;
  color: var(--text-main);
  margin-bottom: 8px;
  line-height: 1.5;
}

.note-preview-box.ql-editor {
  padding: 8px 12px;
  white-space: normal;
}

.note-preview-box p:first-child {
  margin-top: 0;
}

.note-preview-box p:last-child {
  margin-bottom: 0;
}

.note-preview-box p:empty,
.note-preview-box p>br:only-child {
  display: none;
}

.note-preview-box a,
.ql-editor a {
  color: var(--accent-color);
  text-decoration: underline;
}

.note-preview-box p,
.ql-editor p {
  margin: 0 0 6px 0;
}

.note-preview-box p:last-child,
.ql-editor p:last-child {
  margin-bottom: 0;
}

/* Dark mode adjustments for Quill */
.dark .ql-toolbar.ql-snow {
  border-color: var(--card-border);
  background: var(--bg-gradient);
  border-top-left-radius: 6px;
  border-top-right-radius: 6px;
}

.dark .ql-container.ql-snow {
  border-color: var(--card-border);
  background: var(--card-bg);
  font-family: 'Inter', sans-serif;
  font-size: 14px;
  color: var(--text-main);
  border-bottom-left-radius: 6px;
  border-bottom-right-radius: 6px;
}

.dark .ql-snow .ql-stroke {
  stroke: var(--text-main);
}

.dark .ql-snow .ql-fill {
  fill: var(--text-main);
}

.dark .ql-snow .ql-picker {
  color: var(--text-main);
}

.dark .ql-snow .ql-picker-options {
  background-color: var(--card-bg);
  border-color: var(--card-border);
}

#note-quill-editor {
  display: flex;
  flex-direction: column;
  height: 100%;
}

#note-quill-editor .ql-container {
  flex: 1;
  overflow-y: auto;
  min-height: 150px;
}