:root {
  --primary-color: #6c5ce7;
  --primary-light: #a29bfe;
  --accent-color: #00cec9;
  --danger-color: #ff7675;
  --text-color: #2d3436;
  --text-light: #636e72;
  --bg-color: #ecf0f1;
  --bg-gradient: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
  --note-default: #fff9b1;
  --note-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  --header-bg: rgba(255, 255, 255, 0.9);
  --sidebar-bg: rgba(255, 255, 255, 0.8);
  --card-bg: rgba(255, 255, 255, 0.9);
  --modal-bg: white;
  --border-radius: 12px;
  --transition: all 0.3s ease;
  --font-family: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

.dark-mode {
  --primary-color: #a29bfe;
  --primary-light: #6c5ce7;
  --accent-color: #00b894;
  --danger-color: #d63031;
  --text-color: #dfe6e9;
  --text-light: #b2bec3;
  --bg-color: #2d3436;
  --bg-gradient: linear-gradient(135deg, #1a1a1a 0%, #2d3436 100%);
  --note-default: #2d3436;
  --note-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
  --header-bg: rgba(30, 30, 30, 0.9);
  --sidebar-bg: rgba(30, 30, 30, 0.8);
  --card-bg: rgba(40, 40, 40, 0.9);
  --modal-bg: #2d3436;
}

.sepia-mode {
  --primary-color: #b35900;
  --primary-light: #cc7a00;
  --accent-color: #996633;
  --danger-color: #cc4400;
  --text-color: #4b3621;
  --text-light: #7f684e;
  --bg-color: #f1e5d2;
  --bg-gradient: linear-gradient(135deg, #f1e5d2 0%, #e2d5bc 100%);
  --note-default: #f3e5c1;
  --note-shadow: 0 4px 15px rgba(75, 54, 33, 0.1);
  --header-bg: rgba(241, 229, 210, 0.9);
  --sidebar-bg: rgba(226, 213, 188, 0.8);
  --card-bg: rgba(243, 236, 220, 0.9);
  --modal-bg: #f3ecd8;
}

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

body {
  font-family: var(--font-family);
  color: var(--text-color);
  background: var(--bg-gradient);
  overflow-x: hidden;
  min-height: 100vh;
  position: relative;
  transition: var(--transition);
}

/* Header */
.app-header {
  width: 100%;
  padding: 15px 30px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--header-bg);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  backdrop-filter: blur(5px);
  position: sticky;
  top: 0;
  z-index: 100;
}

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

.app-logo {
  font-size: 32px;
  color: var(--primary-color);
}

.app-title {
  font-size: 28px;
  font-weight: bold;
  background: linear-gradient(45deg, #cf0a0a, #6c5ce7);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.search-container {
  position: relative;
  width: 30%;
  max-width: 400px;
}

.search-container input {
  width: 100%;
  padding: 10px 15px 10px 40px;
  border-radius: 30px;
  border: 2px solid rgba(0, 0, 0, 0.1);
  background: rgba(255, 255, 255, 0.8);
  font-size: 16px;
  transition: var(--transition);
}

.dark-mode .search-container input {
  background: rgba(60, 60, 60, 0.8);
  border-color: rgba(255, 255, 255, 0.1);
  color: var(--text-color);
}

.search-container input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.2);
}

.search-container i {
  position: absolute;
  left: 15px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-light);
}

.toolbar {
  display: flex;
  gap: 15px;
}

.tool-btn {
  background: none;
  border: none;
  font-size: 20px;
  cursor: pointer;
  padding: 10px;
  border-radius: 50%;
  transition: var(--transition);
  color: var(--text-color);
  position: relative;
}

.tool-btn:hover {
  background: rgba(108, 92, 231, 0.1);
  transform: scale(1.1);
  color: var(--primary-color);
}

/* Tooltip */
.tooltip {
  position: relative;
}

.tooltip::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: -35px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(0, 0, 0, 0.8);
  color: white;
  padding: 5px 10px;
  border-radius: 5px;
  font-size: 12px;
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  transition: all 0.2s ease;
}

.tooltip:hover::after {
  opacity: 1;
  visibility: visible;
}

main {
  display: flex;
  height: calc(100vh - 80px);
}

.sidebar {
  width: 250px;
  background: var(--sidebar-bg);
  backdrop-filter: blur(5px);
  padding: 20px;
  border-right: 1px solid rgba(0, 0, 0, 0.1);
  display: flex;
  flex-direction: column;
  gap: 30px;
  overflow-y: auto;
  transition: var(--transition);
}

.dark-mode .sidebar {
  border-color: rgba(255, 255, 255, 0.1);
}

.categories, .quick-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.categories h3, .quick-actions h3 {
  font-size: 16px;
  margin-bottom: 10px;
  color: var(--text-light);
}

#category-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

#category-list li {
  padding: 8px 12px;
  border-radius: 8px;
  cursor: pointer;
  transition: var(--transition);
  font-size: 14px;
}

#category-list li:hover {
  background: rgba(108, 92, 231, 0.1);
}

#category-list li.active {
  background: var(--primary-color);
  color: white;
}

.btn-small {
  padding: 6px 12px;
  background: var(--primary-light);
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-size: 12px;
  margin-top: 10px;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
}

.btn-small:hover {
  background: var(--primary-color);
  transform: translateY(-2px);
}

.action-btn {
  padding: 8px 12px;
  background: var(--card-bg);
  color: var(--text-color);
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 8px;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
}

.action-btn:hover {
  background: rgba(108, 92, 231, 0.1);
  transform: translateY(-2px);
}

.action-btn.danger {
  color: var(--danger-color);
}

.action-btn.danger:hover {
  background: rgba(255, 118, 117, 0.1);
}

.notes-area {
  flex: 1;
  overflow: auto;
  padding: 20px;
  position: relative;
}

.notes-container {
  position: relative;
  min-height: 100vh;
  width: 100%;
  padding: 10px;
}

.view-list .notes-container {
  display: flex;
  flex-direction: column;
}

.view-list .note {
  position: relative !important;
  width: 100% !important;
  height: auto !important;
  max-width: 800px;
  margin: 0 auto 20px auto !important;
  left: auto !important;
  top: auto !important;
}

.note {
  background: var(--note-default);
  border-radius: 15px;
  box-shadow: var(--note-shadow);
  width: 250px;
  height: 250px;
  box-sizing: border-box;
  position: relative;
  transition: box-shadow 0.2s ease;
  display: flex;
  flex-direction: column;
  cursor: grab;
  overflow: hidden;
  touch-action: none;
  transform: translate3d(0, 0, 0);
  will-change: transform;
}

.note.dragging {
  cursor: grabbing;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.25);
  opacity: 0.95;
  transform: scale(1.02);
  transition: none;
  z-index: 1000 !important;
  will-change: left, top;
  pointer-events: none;
}

.note:active {
  cursor: grabbing;
}

.note-header {
  height: 30px;
  margin: 0;
  padding: 0 10px;
  border-radius: 15px 15px 0 0;
  background-color: rgba(0, 0, 0, 0.05);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.note-drag-handle {
  width: 40px;
  height: 5px;
  background: rgba(0, 0, 0, 0.1);
  border-radius: 10px;
  margin: 0 auto;
  cursor: grab;
}

.note-tools {
  display: flex;
  gap: 5px;
}

.note-tool {
  background: none;
  border: none;
  font-size: 14px;
  color: rgba(0, 0, 0, 0.5);
  cursor: pointer;
  padding: 3px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.dark-mode .note-tool {
  color: rgba(255, 255, 255, 0.5);
}

.note-tool:hover {
  background: rgba(0, 0, 0, 0.1);
  color: var(--text-color);
}

.note-title {
  padding: 10px 15px 5px;
  font-weight: 600;
  font-size: 18px;
  min-height: 30px;
}

.note-content {
  flex: 1;
  padding: 5px 15px 10px;
  font-size: 14px;
  line-height: 1.5;
  overflow-y: auto;
}

.note-content:focus, .note-title:focus {
  outline: none;
  background: rgba(255, 255, 255, 0.2);
}

.note-footer {
  padding: 8px 15px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: var(--text-light);
  border-top: 1px solid rgba(0, 0, 0, 0.05);
}

.note-category {
  padding: 2px 8px;
  background: rgba(0, 0, 0, 0.1);
  border-radius: 10px;
}

.dark-mode .note-category {
  background: rgba(255, 255, 255, 0.1);
}

.canvas-container {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(255, 255, 255, 0.95);
  z-index: 1000;
}

.dark-mode .canvas-container {
  background: rgba(0, 0, 0, 0.95);
}

#whiteboard {
  cursor: crosshair;
}

.canvas-tools {
  position: fixed;
  top: 20px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 10px;
  padding: 15px;
  background: var(--card-bg);
  border-radius: var(--border-radius);
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  align-items: center;
  backdrop-filter: blur(5px);
}

.tool-select {
  padding: 8px 12px;
  border-radius: 8px;
  border: 1px solid rgba(0, 0, 0, 0.1);
  background: white;
  color: var(--text-color);
  font-family: var(--font-family);
}

.dark-mode .tool-select {
  background: #333;
  border-color: rgba(255, 255, 255, 0.1);
  color: var(--text-color);
}

.color-picker {
  width: 40px;
  height: 40px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

.size-slider {
  width: 120px;
  margin: 0 10px;
  -webkit-appearance: none;
  height: 5px;
  border-radius: 5px;
  background: #ddd;
  outline: none;
}

.dark-mode .size-slider {
  background: #555;
}

.size-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--primary-color);
  cursor: pointer;
}

.btn {
  padding: 8px 15px;
  border-radius: 8px;
  border: none;
  background: var(--primary-color);
  color: white;
  cursor: pointer;
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: var(--transition);
}

.btn:hover {
  background: var(--primary-light);
  transform: translateY(-2px);
}

.add-note-container {
  position: fixed;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 15px;
  padding: 15px;
  background: var(--card-bg);
  border-radius: 15px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  backdrop-filter: blur(5px);
  width: 80%;
  max-width: 800px;
  align-items: center;
  z-index: 90;
}

.note-input-group {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  flex: 1;
}

.note-title-input {
  padding: 12px;
  border-radius: 10px;
  border: 2px solid rgba(0, 0, 0, 0.1);
  font-size: 16px;
  font-weight: 600;
  outline: none;
  transition: var(--transition);
  flex: 1;
  min-width: 100px;
  background: rgba(255, 255, 255, 0.8);
}

.add-note-input {
  padding: 12px;
  border-radius: 10px;
  border: 2px solid rgba(0, 0, 0, 0.1);
  font-size: 14px;
  outline: none;
  transition: var(--transition);
  flex: 3;
  min-width: 200px;
  background: rgba(255, 255, 255, 0.8);
}

.dark-mode .note-title-input,
.dark-mode .add-note-input {
  background: rgba(60, 60, 60, 0.8);
  border-color: rgba(255, 255, 255, 0.1);
  color: var(--text-color);
}

.note-title-input:focus,
.add-note-input:focus {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.2);
}

#note-category, #note-color {
  padding: 12px;
  border-radius: 10px;
  border: 2px solid rgba(0, 0, 0, 0.1);
  background: rgba(255, 255, 255, 0.8);
  outline: none;
  transition: var(--transition);
}

.dark-mode #note-category {
  background: rgba(60, 60, 60, 0.8);
  border-color: rgba(255, 255, 255, 0.1);
  color: var(--text-color);
}

#note-color {
  width: 50px;
  height: 45px;
  padding: 5px;
  cursor: pointer;
}

.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 1001;
  justify-content: center;
  align-items: center;
}

.modal-content {
  background: var(--modal-bg);
  border-radius: var(--border-radius);
  width: 90%;
  max-width: 500px;
  overflow: hidden;
  box-shadow: 0 5px 30px rgba(0, 0, 0, 0.3);
  animation: modalFadeIn 0.3s;
}

@keyframes modalFadeIn {
  from {
    opacity: 0;
    transform: translateY(50px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 20px;
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.dark-mode .modal-header {
  border-color: rgba(255, 255, 255, 0.1);
}

.modal-header h2 {
  font-size: 20px;
  font-weight: 600;
}

.close-modal {
  background: none;
  border: none;
  font-size: 20px;
  cursor: pointer;
  color: var(--text-light);
  transition: var(--transition);
}

.close-modal:hover {
  color: var(--danger-color);
}

.modal-body {
  padding: 20px;
}

.setting-group {
  margin-bottom: 25px;
}

.setting-group h3 {
  font-size: 16px;
  margin-bottom: 10px;
  color: var(--text-light);
}

.theme-options {
  display: flex;
  gap: 10px;
}

.theme-btn {
  padding: 8px 15px;
  border-radius: 8px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: var(--transition);
}

.theme-btn[data-theme="light"] {
  background: #ecf0f1;
  color: #2d3436;
}

.theme-btn[data-theme="dark"] {
  background: #2d3436;
  color: #ecf0f1;
}

.theme-btn[data-theme="sepia"] {
  background: #f1e5d2;
  color: #4b3621;
}

.theme-btn.active {
  border-color: var(--primary-color);
}

.switch {
  position: relative;
  display: inline-block;
  width: 60px;
  height: 34px;
}

.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: #ccc;
  transition: .4s;
}

.slider:before {
  position: absolute;
  content: "";
  height: 26px;
  width: 26px;
  left: 4px;
  bottom: 4px;
  background-color: white;
  transition: .4s;
}

input:checked + .slider {
  background-color: var(--primary-color);
}

input:checked + .slider:before {
  transform: translateX(26px);
}

.slider.round {
  border-radius: 34px;
}

.slider.round:before {
  border-radius: 50%;
}

.export-options {
  display: flex;
  justify-content: space-around;
  gap: 15px;
}

.export-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding: 15px;
  border-radius: 10px;
  border: 1px solid rgba(0, 0, 0, 0.1);
  background: rgba(255, 255, 255, 0.5);
  cursor: pointer;
  transition: var(--transition);
  flex: 1;
}

.dark-mode .export-btn {
  background: rgba(60, 60, 60, 0.5);
  border-color: rgba(255, 255, 255, 0.1);
}

.export-btn:hover {
  background: rgba(108, 92, 231, 0.1);
  transform: translateY(-2px);
}

.export-btn i {
  font-size: 24px;
  color: var(--primary-color);
}

.toast {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background: rgba(0, 0, 0, 0.8);
  color: white;
  padding: 12px 20px;
  border-radius: 10px;
  font-size: 14px;
  max-width: 300px;
  z-index: 2000;
  opacity: 0;
  transform: translateY(50px);
  transition: all 0.3s ease;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 768px) {
  .app-header {
    padding: 15px;
    flex-wrap: wrap;
  }
  
  .search-container {
    order: 3;
    width: 100%;
    margin-top: 15px;
  }

  .sidebar {
    position: fixed;
    left: -250px;
    height: calc(100vh - 140px);
    z-index: 99;
    transition: left 0.3s ease;
  }

  .sidebar.show {
    left: 0;
  }

  .notes-area {
    width: 100%;
  }

  .add-note-container {
    width: 95%;
    flex-direction: column;
  }

  .canvas-tools {
    flex-wrap: wrap;
    justify-content: center;
    max-width: 90%;
  }
}

@media (max-width: 480px) {
  .add-note-container {
    bottom: 15px;
    padding: 10px;
  }

  .note-input-group {
    flex-direction: column;
  }

  .theme-options, .export-options {
    flex-direction: column;
  }
}