* {
  box-sizing: border-box;
}
body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: #f0f4f8;
  display: flex;
  justify-content: center;
  padding: 30px 15px;
  min-height: 100vh;
  margin: 0;
}
.container {
  width: 100%;
  max-width: 450px;
  background: white;
  padding: 30px 25px;
  border-radius: 10px;
  box-shadow: 0 6px 15px rgba(0,0,0,0.1);
}
h1 {
  text-align: center;
  margin-bottom: 20px;
  color: #333;
}
.input-group {
  display: flex;
  margin-bottom: 20px;
}
#taskInput {
  flex: 1;
  padding: 12px 15px;
  font-size: 16px;
  border: 2px solid #ccc;
  border-radius: 8px 0 0 8px;
  outline: none;
  transition: border-color 0.3s;
}
#taskInput:focus {
  border-color: #007BFF;
}
#addBtn {
  padding: 12px 20px;
  background: #007BFF;
  border: none;
  color: white;
  font-weight: 600;
  cursor: pointer;
  border-radius: 0 8px 8px 0;
  transition: background 0.3s;
}
#addBtn:hover {
  background: #0056b3;
}
.filter-group {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-bottom: 25px;
}
.filter-btn {
  background: #e2e8f0;
  border: none;
  padding: 8px 16px;
  border-radius: 20px;
  cursor: pointer;
  font-weight: 600;
  color: #555;
  transition: background 0.3s, color 0.3s;
}
.filter-btn.active,
.filter-btn:hover {
  background: #007BFF;
  color: white;
}
#taskList {
  list-style: none;
  padding: 0;
  margin: 0;
}
.task-item {
  display: flex;
  align-items: center;
  background: #f8fafc;
  padding: 12px 15px;
  margin-bottom: 10px;
  border-radius: 8px;
  box-shadow: 0 1px 4px rgba(0,0,0,0.1);
}
.task-item.completed .task-text {
  text-decoration: line-through;
  color: #999;
}
.task-text {
  flex: 1;
  cursor: pointer;
  font-size: 16px;
  user-select: none;
}
.task-text.editable {
  border-bottom: 1px dotted #666;
  user-select: text;
  cursor: text;
}
.task-buttons {
  display: flex;
  gap: 8px;
}
button.action-btn {
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px 7px;
  color: #666;
  font-size: 18px;
  transition: color 0.3s;
}
button.action-btn:hover {
  color: #007BFF;
}
/* Tick style */
input[type="checkbox"] {
  margin-right: 12px;
  width: 20px;
  height: 20px;
  cursor: pointer;
}