/* ========================================
   GLOBAL STYLES
   ======================================== */

/* Reset default browser margins/padding */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;  /* Makes width include padding/border */
}

/* Body styling - applies to entire page */
body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;  /* Full viewport height */
  display: flex;
  justify-content: center;  /* Center horizontally */
  align-items: center;      /* Center vertically */
  padding: 20px;
}

/* ========================================
   MAIN CONTAINER
   ======================================== */

.container {
  background: white;
  border-radius: 15px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  width: 100%;
  max-width: 550px;  /* Don't get too wide on big screens */
  padding: 30px;
}

h1 {
  text-align: center;
  color: #333;
  margin-bottom: 25px;
  font-size: 2rem;
}

/* ========================================
   INPUT SECTION
   ======================================== */

.input-section {
  display: flex;
  gap: 10px;  /* Space between input and button */
  margin-bottom: 25px;
}

#taskInput {
  flex: 1;  /* Takes remaining space */
  padding: 12px 15px;
  border: 2px solid #e0e0e0;
  border-radius: 8px;
  font-size: 16px;
  transition: border-color 0.3s;
}

#taskInput:focus {
  outline: none;
  border-color: #667eea;  /* Purple border when focused */
}

#addBtn {
  background: #667eea;
  color: white;
  border: none;
  padding: 12px 20px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 16px;
  font-weight: bold;
  transition: background 0.3s, transform 0.1s;
}

#addBtn:hover {
  background: #5a67d8;  /* Darker on hover */
}

#addBtn:active {
  transform: scale(0.98);  /* Slight press effect */
}

/* ========================================
   FILTER BUTTONS
   ======================================== */

.filters {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
  justify-content: center;
}

.filter-btn {
  background: #f0f0f0;
  border: none;
  padding: 8px 16px;
  border-radius: 20px;
  cursor: pointer;
  font-size: 14px;
  transition: all 0.3s;
}

.filter-btn:hover {
  background: #e0e0e0;
}

.filter-btn.active {
  background: #667eea;
  color: white;
}

/* ========================================
   TASK LIST
   ======================================== */

#taskList {
  list-style: none;  /* Remove bullet points */
  margin-bottom: 20px;
  max-height: 400px;
  overflow-y: auto;  /* Scroll if too many tasks */
}

/* Individual task item */
.task-item {
  display: flex;
  align-items: center;
  padding: 12px;
  background: #f8f9fa;
  border-radius: 8px;
  margin-bottom: 8px;
  transition: all 0.3s;
}

.task-item:hover {
  background: #e9ecef;
  transform: translateX(5px);
}

/* Checkbox styling */
.task-checkbox {
  width: 20px;
  height: 20px;
  margin-right: 12px;
  cursor: pointer;
}

/* Task text */
.task-text {
  flex: 1;
  font-size: 16px;
  color: #333;
  word-break: break-word;
}

/* Completed task text (strikethrough) */
.task-text.completed {
  text-decoration: line-through;
  color: #aaa;
}

/* Delete button */
.delete-btn {
  background: #dc3545;
  color: white;
  border: none;
  padding: 6px 12px;
  border-radius: 5px;
  cursor: pointer;
  font-size: 12px;
  transition: background 0.3s;
}

.delete-btn:hover {
  background: #c82333;
}

/* ========================================
   COUNTER SECTION
   ======================================== */

.counter {
  text-align: center;
  padding-top: 15px;
  border-top: 2px solid #f0f0f0;
  color: #666;
  font-size: 14px;
}

#taskCount {
  font-weight: bold;
  color: #667eea;
  font-size: 18px;
}

/* ========================================
   RESPONSIVE DESIGN
   ======================================== */

/* On small screens, stack input and button */
@media (max-width: 500px) {
  .container {
    padding: 20px;
  }

  .input-section {
    flex-direction: column;
  }

  .filters {
    flex-wrap: wrap;
  }
}