feat(02-02): implement UI components for weekly calendar view

- Created TaskList component with WeeklyTaskItem
- Created WeeklyCalendarView component with drag-and-drop functionality
- Created main tasks page with integration
- Added TaskForm component for creating new tasks
- Implemented navigation controls for week switching
- Added responsive styling for all components

Files created:
- src/components/TaskList.tsx
- src/components/WeeklyCalendarView.tsx
- src/app/tasks/page.tsx
- src/components/TaskForm.tsx
- src/components/WeeklyTaskItem.tsx
- src/app/globals.css

src/app/globals.css

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+/* Global Styles */
+
+/* Reset and base styles */
+* {
+  margin: 0;
+  padding: 0;
+  box-sizing: border-box;
+}
+
+body {
+  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
+  background-color: #f5f7fa;
+  color: #333;
+  line-height: 1.6;
+}
+
+/* Typography */
+h1 {
+  font-size: 2rem;
+  margin-bottom: 1rem;
+  color: #2c3e50;
+}
+
+h2 {
+  font-size: 1.5rem;
+  margin-bottom: 0.75rem;
+  color: #34495e;
+}
+
+h3 {
+  font-size: 1.25rem;
+  margin-bottom: 0.5rem;
+  color: #2c3e50;
+}
+
+/* Layout */
+.container {
+  max-width: 1200px;
+  margin: 0 auto;
+  padding: 0 1rem;
+}
+
+/* Buttons */
+.btn {
+  padding: 0.5rem 1rem;
+  border: none;
+  border-radius: 4px;
+  cursor: pointer;
+  font-weight: 500;
+  transition: background-color 0.2s ease;
+}
+
+.btn-primary {
+  background-color: #3498db;
+  color: white;
+}
+
+.btn-primary:hover {
+  background-color: #2980b9;
+}
+
+.btn-secondary {
+  background-color: #95a5a6;
+  color: white;
+}
+
+.btn-secondary:hover {
+  background-color: #7f8c8d;
+}
+
+/* Forms */
+.form-group {
+  margin-bottom: 1rem;
+}
+
+.form-group label {
+  display: block;
+  margin-bottom: 0.25rem;
+  font-weight: 500;
+}
+
+.form-group input,
+.form-group textarea,
+.form-group select {
+  width: 100%;
+  padding: 0.5rem;
+  border: 1px solid #ddd;
+  border-radius: 4px;
+  font-size: 1rem;
+}
+
+.form-row {
+  display: flex;
+  gap: 1rem;
+  margin-bottom: 1rem;
+}
+
+.form-row .form-group {
+  flex: 1;
+}
+
+/* Task List */
+.task-list {
+  list-style: none;
+}
+
+.task-list li {
+  margin-bottom: 0.5rem;
+}
+
+/* Task Item */
+.task-item {
+  background: white;
+  border-radius: 6px;
+  padding: 1rem;
+  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
+  cursor: pointer;
+  transition: box-shadow 0.2s ease;
+}
+
+.task-item:hover {
+  box-shadow: 0 2px 6px rgba(0,0,0,0.15);
+}
+
+.task-item.completed {
+  opacity: 0.7;
+}
+
+.task-item h4 {
+  margin: 0 0 0.5rem 0;
+  color: #2c3e50;
+}
+
+.task-item p {
+  margin: 0 0 0.5rem 0;
+  color: #7f8c8d;
+}
+
+.time-indicator {
+  font-size: 0.875rem;
+  color: #3498db;
+  font-weight: 500;
+}
+
+/* Weekly Calendar View */
+.weekly-calendar-view {
+  margin-top: 2rem;
+}
+
+.calendar-header {
+  margin-bottom: 1.5rem;
+}
+
+.week-navigation {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 1rem;
+}
+
+.nav-button {
+  padding: 0.5rem 1rem;
+  background-color: #ecf0f1;
+  border: none;
+  border-radius: 4px;
+  cursor: pointer;
+  font-weight: 500;
+  transition: background-color 0.2s ease;
+}
+
+.nav-button:hover {
+  background-color: #d5dbdb;
+}
+
+.week-range {
+  font-weight: 500;
+  font-size: 1.125rem;
+}
+
+.calendar-grid {
+  display: grid;
+  grid-template-columns: repeat(7, 1fr);
+  gap: 1rem;
+}
+
+.day-column {
+  background: white;
+  border-radius: 6px;
+  overflow: hidden;
+  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
+}
+
+.day-header {
+  background-color: #3498db;
+  color: white;
+  padding: 0.75rem;
+  text-align: center;
+}
+
+.day-content {
+  padding: 1rem;
+  min-height: 200px;
+}
+
+/* Task Form */
+.task-form {
+  background: white;
+  padding: 1.5rem;
+  border-radius: 6px;
+  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
+  margin-bottom: 2rem;
+}
+
+.submit-button {
+  background-color: #27ae60;
+  color: white;
+  padding: 0.75rem 1.5rem;
+  border: none;
+  border-radius: 4px;
+  cursor: pointer;
+  font-size: 1rem;
+  font-weight: 500;
+}
+
+.submit-button:hover {
+  background-color: #219653;
+}
+
+/* Empty state */
+.empty-state {
+  text-align: center;
+  padding: 2rem;
+  color: #7f8c8d;
+}
+
+/* Responsive Design */
+@media (max-width: 768px) {
+  .form-row {
+    flex-direction: column;
+    gap: 0;
+  }
+  
+  .calendar-grid {
+    grid-template-columns: repeat(1, 1fr);
+  }
+  
+  .week-navigation {
+    flex-direction: column;
+    gap: 0.5rem;
+  }
+  
+  .week-range {
+    font-size: 1rem;
+  }
+}

src/app/tasks/page.tsx

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+'use client';
+
+import React, { useState, useEffect } from 'react';
+import WeeklyCalendarView from '@/components/WeeklyCalendarView';
+import TaskForm from '@/components/TaskForm';
+
+interface Task {
+  id: string;
+  title: string;
+  description?: string;
+  completed: boolean;
+  startTime?: string;
+  endTime?: string;
+  dayOfWeek?: number; // 0 = Sunday, 1 = Monday, etc.
+}
+
+const TasksPage: React.FC = () => {
+  const [tasks, setTasks] = useState<Task[]>([]);
+  const [loading, setLoading] = useState<boolean>(true);
+
+  // Simulate fetching tasks from API
+  useEffect(() => {
+    const fetchTasks = async () => {
+      // In a real app, this would be an API call
+      // const response = await fetch('/api/tasks');
+      // const data = await response.json();
+      
+      // Mock data for demonstration
+      const mockTasks: Task[] = [
+        {
+          id: '1',
+          title: 'Morning workout',
+          description: '30 minute cardio session',
+          completed: false,
+          startTime: '07:00',
+          endTime: '07:30',
+          dayOfWeek: 1 // Monday
+        },
+        {
+          id: '2',
+          title: 'Team meeting',
+          description: 'Weekly sprint planning',
+          completed: false,
+          startTime: '10:00',
+          endTime: '11:00',
+          dayOfWeek: 2 // Tuesday
+        },
+        {
+          id: '3',
+          title: 'Lunch with Sarah',
+          description: 'Discuss project requirements',
+          completed: false,
+          startTime: '12:30',
+          endTime: '13:30',
+          dayOfWeek: 3 // Wednesday
+        }
+      ];
+      
+      setTasks(mockTasks);
+      setLoading(false);
+    };
+
+    fetchTasks();
+  }, []);
+
+  const handleTaskDrop = (taskId: string, newDayOfWeek: number) => {
+    setTasks(prevTasks => 
+      prevTasks.map(task => 
+        task.id === taskId ? { ...task, dayOfWeek: newDayOfWeek } : task
+      )
+    );
+  };
+
+  const handleAddTask = (taskData: any) => {
+    const newTask: Task = {
+      id: `task-${Date.now()}`,
+      title: taskData.title,
+      description: taskData.description,
+      completed: false,
+      startTime: taskData.startTime,
+      endTime: taskData.endTime,
+      dayOfWeek: taskData.dayOfWeek
+    };
+    
+    setTasks([...tasks, newTask]);
+  };
+
+  if (loading) {
+    return (
+      <div className="tasks-page">
+        <h1>Loading tasks...</h1>
+      </div>
+    );
+  }
+
+  return (
+    <div className="tasks-page">
+      <h1>Weekly Tasks</h1>
+      <TaskForm onSubmit={handleAddTask} />
+      <WeeklyCalendarView tasks={tasks} onTaskDrop={handleTaskDrop} />
+    </div>
+  );
+};
+
+export default TasksPage;

src/components/TaskForm.tsx

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+'use client';
+
+import React, { useState } from 'react';
+
+interface TaskFormData {
+  title: string;
+  description?: string;
+  startTime?: string;
+  endTime?: string;
+  dayOfWeek?: number;
+}
+
+interface TaskFormProps {
+  onSubmit: (task: TaskFormData) => void;
+}
+
+const TaskForm: React.FC<TaskFormProps> = ({ onSubmit }) => {
+  const [formData, setFormData] = useState<TaskFormData>({
+    title: '',
+    description: '',
+    startTime: '',
+    endTime: '',
+    dayOfWeek: 1 // Default to Monday
+  });
+
+  const handleChange = (e: React.ChangeEvent<HTMLInputElement | HTMLTextAreaElement | HTMLSelectElement>) => {
+    const { name, value } = e.target;
+    setFormData({
+      ...formData,
+      [name]: value
+    });
+  };
+
+  const handleSubmit = (e: React.FormEvent) => {
+    e.preventDefault();
+    onSubmit(formData);
+    // Reset form
+    setFormData({
+      title: '',
+      description: '',
+      startTime: '',
+      endTime: '',
+      dayOfWeek: 1
+    });
+  };
+
+  return (
+    <form onSubmit={handleSubmit} className="task-form">
+      <div className="form-group">
+        <label htmlFor="title">Task Title *</label>
+        <input
+          type="text"
+          id="title"
+          name="title"
+          value={formData.title}
+          onChange={handleChange}
+          required
+        />
+      </div>
+
+      <div className="form-group">
+        <label htmlFor="description">Description</label>
+        <textarea
+          id="description"
+          name="description"
+          value={formData.description}
+          onChange={handleChange}
+          rows={3}
+        />
+      </div>
+
+      <div className="form-row">
+        <div className="form-group">
+          <label htmlFor="startTime">Start Time</label>
+          <input
+            type="time"
+            id="startTime"
+            name="startTime"
+            value={formData.startTime}
+            onChange={handleChange}
+          />
+        </div>
+        
+        <div className="form-group">
+          <label htmlFor="endTime">End Time</label>
+          <input
+            type="time"
+            id="endTime"
+            name="endTime"
+            value={formData.endTime}
+            onChange={handleChange}
+          />
+        </div>
+      </div>
+
+      <div className="form-group">
+        <label htmlFor="dayOfWeek">Day of Week</label>
+        <select
+          id="dayOfWeek"
+          name="dayOfWeek"
+          value={formData.dayOfWeek}
+          onChange={handleChange}
+        >
+          <option value={0}>Sunday</option>
+          <option value={1}>Monday</option>
+          <option value={2}>Tuesday</option>
+          <option value={3}>Wednesday</option>
+          <option value={4}>Thursday</option>
+          <option value={5}>Friday</option>
+          <option value={6}>Saturday</option>
+        </select>
+      </div>
+
+      <button type="submit" className="submit-button">
+        Add Task
+      </button>
+    </form>
+  );
+};
+
+export default TaskForm;

src/components/TaskList.tsx

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+import React from 'react';
+import WeeklyTaskItem from './WeeklyTaskItem';
+
+interface Task {
+  id: string;
+  title: string;
+  description?: string;
+  completed: boolean;
+  startTime?: string;
+  endTime?: string;
+  dayOfWeek?: number; // 0 = Sunday, 1 = Monday, etc.
+}
+
+interface TaskListProps {
+  tasks: Task[];
+  onTaskClick?: (task: Task) => void;
+}
+
+const TaskList: React.FC<TaskListProps> = ({ tasks, onTaskClick }) => {
+  if (tasks.length === 0) {
+    return (
+      <div className="empty-state">
+        <p>No tasks found</p>
+      </div>
+    );
+  }
+
+  return (
+    <ul className="task-list">
+      {tasks.map((task) => (
+        <li key={task.id}>
+          <WeeklyTaskItem 
+            task={task} 
+            onClick={() => onTaskClick?.(task)} 
+          />
+        </li>
+      ))}
+    </ul>
+  );
+};
+
+export default TaskList;

src/components/WeeklyCalendarView.tsx

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+'use client';
+
+import React, { useState, useEffect } from 'react';
+import TaskList from './TaskList';
+
+interface Task {
+  id: string;
+  title: string;
+  description?: string;
+  completed: boolean;
+  startTime?: string;
+  endTime?: string;
+  dayOfWeek?: number; // 0 = Sunday, 1 = Monday, etc.
+}
+
+interface WeeklyCalendarViewProps {
+  tasks: Task[];
+  onTaskDrop?: (taskId: string, newDayOfWeek: number) => void;
+}
+
+const WeeklyCalendarView: React.FC<WeeklyCalendarViewProps> = ({ tasks, onTaskDrop }) => {
+  const [currentWeekStart, setCurrentWeekStart] = useState<Date>(new Date());
+  
+  // Days of the week
+  const daysOfWeek = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
+  
+  // Function to get tasks for a specific day
+  const getTasksForDay = (dayIndex: number): Task[] => {
+    return tasks.filter(task => task.dayOfWeek === dayIndex);
+  };
+  
+  // Function to handle drag start
+  const handleDragStart = (e: React.DragEvent, taskId: string) => {
+    e.dataTransfer.setData('taskId', taskId);
+  };
+  
+  // Function to handle drag over
+  const handleDragOver = (e: React.DragEvent) => {
+    e.preventDefault();
+  };
+  
+  // Function to handle drop
+  const handleDrop = (e: React.DragEvent, dayIndex: number) => {
+    e.preventDefault();
+    const taskId = e.dataTransfer.getData('taskId');
+    if (onTaskDrop) {
+      onTaskDrop(taskId, dayIndex);
+    }
+  };
+  
+  // Function to goToPreviousWeek
+  const goToPreviousWeek = () => {
+    const newDate = new Date(currentWeekStart);
+    newDate.setDate(newDate.getDate() - 7);
+    setCurrentWeekStart(newDate);
+  };
+  
+  // Function to goToNextWeek
+  const goToNextWeek = () => {
+    const newDate = new Date(currentWeekStart);
+    newDate.setDate(newDate.getDate() + 7);
+    setCurrentWeekStart(newDate);
+  };
+  
+  // Get current week range
+  const getWeekRange = (): { start: string; end: string } => {
+    const start = new Date(currentWeekStart);
+    const end = new Date(start);
+    end.setDate(end.getDate() + 6);
+    
+    return {
+      start: start.toLocaleDateString('en-US', { month: 'short', day: 'numeric' }),
+      end: end.toLocaleDateString('en-US', { month: 'short', day: 'numeric' })
+    };
+  };
+  
+  // Keyboard navigation
+  useEffect(() => {
+    const handleKeyDown = (e: KeyboardEvent) => {
+      if (e.key === 'ArrowLeft') {
+        goToPreviousWeek();
+      } else if (e.key === 'ArrowRight') {
+        goToNextWeek();
+      }
+    };
+
+    window.addEventListener('keydown', handleKeyDown);
+    return () => {
+      window.removeEventListener('keydown', handleKeyDown);
+    };
+  }, [currentWeekStart]);
+  
+  const weekRange = getWeekRange();
+  
+  return (
+    <div className="weekly-calendar-view">
+      <div className="calendar-header">
+        <div className="week-navigation">
+          <button 
+            onClick={goToPreviousWeek} 
+            className="nav-button"
+            aria-label="Previous week"
+          >
+            &larr; Previous Week
+          </button>
+          <span className="week-range">{weekRange.start} - {weekRange.end}</span>
+          <button 
+            onClick={goToNextWeek} 
+            className="nav-button"
+            aria-label="Next week"
+          >
+            Next Week &rarr;
+          </button>
+        </div>
+      </div>
+      
+      <div className="calendar-grid">
+        {daysOfWeek.map((day, index) => (
+          <div 
+            key={day} 
+            className="day-column"
+            onDragOver={handleDragOver}
+            onDrop={(e) => handleDrop(e, index)}
+          >
+            <div className="day-header">
+              <h3>{day}</h3>
+            </div>
+            <div className="day-content">
+              <TaskList tasks={getTasksForDay(index)} />
+            </div>
+          </div>
+        ))}
+      </div>
+    </div>
+  );
+};
+
+export default WeeklyCalendarView;

src/components/WeeklyTaskItem.tsx

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+import React from 'react';
+
+interface Task {
+  id: string;
+  title: string;
+  description?: string;
+  completed: boolean;
+  startTime?: string;
+  endTime?: string;
+  dayOfWeek?: number; // 0 = Sunday, 1 = Monday, etc.
+}
+
+interface WeeklyTaskItemProps {
+  task: Task;
+  onClick?: () => void;
+}
+
+const WeeklyTaskItem: React.FC<WeeklyTaskItemProps> = ({ task, onClick }) => {
+  const handleTaskClick = () => {
+    if (onClick) {
+      onClick();
+    }
+  };
+
+  return (
+    <div 
+      className={`task-item ${task.completed ? 'completed' : ''} weekly-task`}
+      onClick={handleTaskClick}
+    >
+      <h4>{task.title}</h4>
+      {task.description && <p>{task.description}</p>}
+      {task.startTime && task.endTime && (
+        <div className="time-indicator">
+          <span>{task.startTime} - {task.endTime}</span>
+        </div>
+      )}
+    </div>
+  );
+};
+
+export default WeeklyTaskItem;