* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    font-family: "Work Sans", sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: 0.3s linear;
  }
  
  /* Theme styles */
  .standard {
    background-image: linear-gradient(100deg, #575656, #062e3f);
    color: #ffdfdb;
  }
  
  .light {
    background-image: linear-gradient(100deg, #d4f1ff, #ffffff);
    color: #1a150e;
  }
  
  .darker {
    background-image: linear-gradient(100deg, #001214, #001f29);
    color: white;
  }
  
  /* Header styles */
  #header {
    padding: 1.5rem;
    text-align: center;
    position: relative;
  }
  
  .flexrow-container {
    display: flex;
    justify-content: flex-end;
    margin-bottom: 1rem;
  }
  
  .theme-selector {
    border: 1px solid #d1dae3;
    border-radius: 100%;
    height: 35px;
    width: 35px;
    margin: 0 8px;
    cursor: pointer;
    transition: transform 150ms ease-in-out, box-shadow 200ms ease-in-out;
  }
  
  .theme-selector:hover {
    box-shadow: white 0 0 8px;
  }
  
  .theme-selector:active {
    transform: scale(0.95);
  }
  
  .standard-theme {
    background-image: linear-gradient(100deg, #575656, #062e3f);
  }
  
  .light-theme {
    background-image: linear-gradient(100deg, #d4f1ff, #ffffff);
  }
  
  .darker-theme {
    background-image: linear-gradient(100deg, #001214, #001f29);
  }
  
  #title {
    font-size: 3rem;
    margin-bottom: 0.5rem;
    letter-spacing: 0.2rem;
    text-align: center;
    position: relative;
    display: inline-block;
  }
  
  #title::after {
    content: "";
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 3px;
    background-color: currentColor;
    animation: underline 2s forwards 0.5s;
  }
  
  @keyframes underline {
    to {
      width: 100%;
    }
  }
  
  #datetime {
    font-size: 1.2rem;
    margin-top: 0.5rem;
    opacity: 0.8;
  }
  
  /* App container */
  .app-container {
    display: flex;
    flex: 1;
    max-width: 1400px;
    margin: 0 auto;
    width: 95%;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
  }
  
  /* Sidebar */
  .sidebar {
    width: 250px;
    padding: 1.5rem;
    border-right: 1px solid rgba(255, 255, 255, 0.1);
    background-color: rgba(0, 0, 0, 0.1);
    display: flex;
    flex-direction: column;
  }
  
  .sidebar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }
  
  .sidebar-header h3 {
    font-size: 1.2rem;
    font-weight: 500;
  }
  
  .icon-btn {
    background: none;
    border: none;
    color: inherit;
    cursor: pointer;
    font-size: 1rem;
    opacity: 0.8;
    transition: opacity 0.2s;
  }
  
  .icon-btn:hover {
    opacity: 1;
  }
  
  #categories-list {
    list-style: none;
    margin-bottom: 2rem;
  }
  
  .category {
    padding: 0.75rem 1rem;
    margin-bottom: 0.5rem;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.2s;
    display: flex;
    align-items: center;
  }
  
  .category i {
    margin-right: 10px;
    width: 20px;
    text-align: center;
  }
  
  .category:hover {
    background-color: rgba(255, 255, 255, 0.1);
  }
  
  .category.active {
    background-color: rgba(255, 255, 255, 0.2);
    font-weight: 500;
  }
  
  .stats-container {
    display: flex;
    justify-content: space-between;
    margin-top: 0.5rem;
  }
  
  .stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 0.75rem;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    width: 30%;
  }
  
  .stat-item span:first-child {
    font-size: 1.5rem;
    font-weight: 500;
    margin-bottom: 0.25rem;
  }
  
  .stat-label {
    font-size: 0.8rem;
    opacity: 0.8;
  }
  
  /* Main content */
  .main-content {
    flex: 1;
    padding: 1.5rem;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
  }
  
  .search-container {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 1rem;
  }
  
  .search-box {
    display: flex;
    align-items: center;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    padding: 0.5rem 1rem;
    flex: 1;
    min-width: 200px;
  }
  
  .search-box i {
    margin-right: 0.5rem;
    opacity: 0.7;
  }
  
  #search-input {
    background: none;
    border: none;
    color: inherit;
    font-size: 1rem;
    outline: none;
    width: 100%;
  }
  
  .filter-container {
    display: flex;
    gap: 0.5rem;
  }
  
  .filter-select {
    background-color: rgba(255, 255, 255, 0.1);
    border: none;
    color: inherit;
    padding: 0.5rem;
    border-radius: 8px;
    cursor: pointer;
    outline: none;
  }
  
  .filter-select option {
    background-color: #333;
    color: white;
  }
  
  /* Form */
  #form {
    margin-bottom: 1.5rem;
  }
  
  #task-form {
    display: flex;
    flex-direction: column;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    padding: 1rem;
  }
  
  .todo-input {
    padding: 0.75rem;
    font-size: 1rem;
    border: none;
    outline: none;
    border-radius: 8px;
    margin-bottom: 1rem;
    background-color: rgba(255, 255, 255, 0.1);
    color: inherit;
  }
  
  .task-options {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
  }
  
  .date-input,
  .priority-select,
  .category-select {
    padding: 0.5rem;
    border: none;
    border-radius: 6px;
    background-color: rgba(255, 255, 255, 0.1);
    color: inherit;
    flex: 1;
    min-width: 120px;
    outline: none;
  }
  
  .priority-select option,
  .category-select option {
    background-color: #333;
    color: white;
  }
  
  .todo-btn {
    padding: 0.75rem;
    font-size: 1rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.2s;
    font-weight: 500;
  }
  
  /* Button themes */
  .standard .todo-btn {
    background-color: rgb(247, 226, 223);
    color: rgb(0, 0, 0);
  }
  
  .standard .todo-btn:hover {
    background-color: white;
  }
  
  .light .todo-btn {
    background-color: white;
    color: #1a150e;
  }
  
  .light .todo-btn:hover {
    background-color: #f0f0f0;
  }
  
  .darker .todo-btn {
    background-color: #002837;
    color: white;
  }
  
  .darker .todo-btn:hover {
    background-color: #001f29;
  }
  
  /* Tasks and Calendar Container */
  .tasks-calendar-container {
    display: flex;
    gap: 1.5rem;
    flex: 1;
    flex-wrap: wrap;
  }
  
  .tasks-container {
    flex: 1;
    min-width: 300px;
  }
  
  #current-category-title {
    margin-bottom: 1rem;
    font-size: 1.5rem;
    font-weight: 500;
  }
  
  .todo-list {
    list-style: none;
  }
  
  .todo-item {
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    margin-bottom: 0.75rem;
    overflow: hidden;
  }
  
  .todo-content {
    padding: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
  }
  
  .todo-checkbox {
    appearance: none;
    -webkit-appearance: none;
    height: 20px;
    width: 20px;
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.5);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
  }
  
  .todo-checkbox:checked {
    background-color: rgba(255, 255, 255, 0.2);
  }
  
  .todo-checkbox:checked::after {
    content: "✓";
    font-size: 0.8rem;
  }
  
  .todo-text {
    flex: 1;
    font-size: 1rem;
  }
  
  .todo-item.completed .todo-text {
    text-decoration: line-through;
    opacity: 0.7;
  }
  
  .todo-details {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-size: 0.8rem;
    opacity: 0.8;
  }
  
  .todo-date,
  .todo-category {
    display: flex;
    align-items: center;
    gap: 0.25rem;
  }
  
  .todo-priority {
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.7rem;
    text-transform: uppercase;
    font-weight: 500;
  }
  
  .priority-high {
    background-color: rgba(255, 87, 87, 0.2);
    color: #ff5757;
  }
  
  .priority-medium {
    background-color: rgba(255, 193, 7, 0.2);
    color: #ffc107;
  }
  
  .priority-low {
    background-color: rgba(13, 202, 240, 0.2);
    color: #0dcaf0;
  }
  
  .todo-actions {
    display: flex;
    gap: 0.5rem;
  }
  
  .todo-action-btn {
    background: none;
    border: none;
    color: inherit;
    cursor: pointer;
    opacity: 0.7;
    transition: opacity 0.2s;
    font-size: 0.9rem;
  }
  
  .todo-action-btn:hover {
    opacity: 1;
  }
  
  /* Calendar */
  .calendar-container {
    width: 350px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    padding: 1rem;
  }
  
  .calendar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
  }
  
  .calendar-nav-btn {
    background: none;
    border: none;
    color: inherit;
    cursor: pointer;
    font-size: 1rem;
    opacity: 0.8;
    transition: opacity 0.2s;
  }
  
  .calendar-nav-btn:hover {
    opacity: 1;
  }
  
  #calendar-title {
    font-size: 1.2rem;
    font-weight: 500;
  }
  
  .weekdays {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    text-align: center;
    font-weight: 500;
    margin-bottom: 0.5rem;
  }
  
  .weekdays div {
    padding: 0.5rem;
    font-size: 0.9rem;
    opacity: 0.8;
  }
  
  .calendar-days {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 5px;
  }
  
  .calendar-day {
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    cursor: pointer;
    position: relative;
    font-size: 0.9rem;
  }
  
  .calendar-day:hover {
    background-color: rgba(255, 255, 255, 0.1);
  }
  
  .calendar-day.today {
    background-color: rgba(255, 255, 255, 0.2);
    font-weight: 500;
  }
  
  .calendar-day.has-tasks::after {
    content: "";
    position: absolute;
    bottom: 3px;
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background-color: currentColor;
  }
  
  .calendar-day.other-month {
    opacity: 0.4;
  }
  
  .calendar-day.selected {
    background-color: rgba(255, 255, 255, 0.3);
    font-weight: 500;
  }
  
  /* Modal */
  .modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    justify-content: center;
    align-items: center;
  }
  
  .modal-content {
    background-color: #2a2a2a;
    color: white;
    padding: 2rem;
    border-radius: 10px;
    width: 90%;
    max-width: 500px;
    position: relative;
  }
  
  .close-modal {
    position: absolute;
    top: 1rem;
    right: 1rem;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0.7;
    transition: opacity 0.2s;
  }
  
  .close-modal:hover {
    opacity: 1;
  }
  
  .modal h3 {
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
  }
  
  .modal input[type="text"] {
    width: 100%;
    padding: 0.75rem;
    margin-bottom: 1rem;
    border: none;
    border-radius: 6px;
    background-color: rgba(255, 255, 255, 0.1);
    color: white;
    font-size: 1rem;
  }
  
  .icon-selector {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.5rem;
    margin-bottom: 1.5rem;
  }
  
  .icon-option {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem;
    border-radius: 6px;
    cursor: pointer;
    background-color: rgba(255, 255, 255, 0.1);
    transition: background-color 0.2s;
  }
  
  .icon-option:hover {
    background-color: rgba(255, 255, 255, 0.2);
  }
  
  .icon-option.selected {
    background-color: rgba(255, 255, 255, 0.3);
  }
  
  .modal button {
    width: 100%;
    padding: 0.75rem;
    border: none;
    border-radius: 6px;
    background-color: #0d6efd;
    color: white;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.2s;
  }
  
  .modal button:hover {
    background-color: #0b5ed7;
  }
  
  /* Task detail modal */
  .task-detail-content {
    margin-bottom: 1.5rem;
  }
  
  .detail-row {
    display: flex;
    margin-bottom: 0.75rem;
  }
  
  .detail-label {
    width: 100px;
    font-weight: 500;
    opacity: 0.8;
  }
  
  .detail-notes {
    margin-top: 1rem;
  }
  
  .detail-notes h4 {
    margin-bottom: 0.5rem;
    opacity: 0.8;
  }
  
  .detail-notes textarea {
    width: 100%;
    height: 100px;
    padding: 0.75rem;
    border: none;
    border-radius: 6px;
    background-color: rgba(255, 255, 255, 0.1);
    color: white;
    font-size: 0.9rem;
    resize: vertical;
  }
  
  .detail-actions {
    display: flex;
    gap: 0.5rem;
  }
  
  .detail-btn {
    flex: 1;
    padding: 0.75rem;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.2s;
  }
  
  .primary-btn {
    background-color: #0d6efd;
    color: white;
  }
  
  .primary-btn:hover {
    background-color: #0b5ed7;
  }
  
  .delete-btn {
    background-color: #dc3545;
    color: white;
  }
  
  .delete-btn:hover {
    background-color: #bb2d3b;
  }
  
  /* Notification */
  .notification {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: #2a2a2a;
    color: white;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    z-index: 1000;
    transform: translateY(150%);
    transition: transform 0.3s ease-in-out;
  }
  
  .notification.show {
    transform: translateY(0);
  }
  
  .notification-content {
    display: flex;
    align-items: center;
    padding: 1rem;
    gap: 1rem;
  }
  
  .notification-content i {
    font-size: 1.5rem;
    color: #ffc107;
  }
  
  .notification-text h4 {
    margin-bottom: 0.25rem;
  }
  
  .notification-text p {
    opacity: 0.8;
    font-size: 0.9rem;
  }
  
  .close-notification {
    background: none;
    border: none;
    color: white;
    cursor: pointer;
    opacity: 0.7;
    transition: opacity 0.2s;
  }
  
  .close-notification:hover {
    opacity: 1;
  }
  
  /* Responsive design */
  @media (max-width: 1100px) {
    .tasks-calendar-container {
      flex-direction: column;
    }
  
    .calendar-container {
      width: 100%;
    }
  }
  
  @media (max-width: 768px) {
    .app-container {
      flex-direction: column;
    }
  
    .sidebar {
      width: 100%;
      border-right: none;
      border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }
  
    #categories-list {
      display: flex;
      flex-wrap: wrap;
      gap: 0.5rem;
    }
  
    .category {
      padding: 0.5rem 0.75rem;
      margin-bottom: 0;
    }
  }
  
  @media (max-width: 480px) {
    #title {
      font-size: 2rem;
    }
  
    .task-options {
      flex-direction: column;
    }
  
    .search-container {
      flex-direction: column;
    }
  }