body {
  font-family: Arial, sans-serif;
  background-color: #f4f4f9;
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  transition: background-color 0.3s, color 0.3s;
}

.main-box {
  width: 90%;
  max-width: 600px;
  padding: 1.5rem;
  background: #ffffff;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
  border-radius: 8px;
  position: relative;
  transition: background 0.3s, box-shadow 0.3s;
}

.box {
  margin: 1rem 0;
  padding: 1rem;
  background: #f9f9f9;
  border-radius: 8px;
  transition: background 0.3s;
}

h1 {
  font-size: 2rem;
  color: #333;
  margin: 0;
}

.box button {
  border: none;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  cursor: pointer;
  font-size: 1rem;
  transition: background-color 0.3s;
}

.add-btn {
  background-color: #007bff;
  color: #ffffff;
}

.add-btn:hover {
  background-color: #0056b3;
}

.add-btn:focus {
  outline: none;
}

.toggle-button {
  background-color: #6c757d5e;
  color: #ffffff;
}

.toggle-button:hover {
  background-color: #5a626882;
}

.toggle-button:focus {
  outline: none;
}

.box .toggle-button {
  position: absolute;
  top: 20px;
  right: 20px;
}

#task-form {
  display: flex;
  gap: 0.5rem;
}

#task-input {
  flex: 1;
  padding: 0.5rem;
  border: 1px solid #ccc;
  border-radius: 4px;
  font-size: 1rem;
}

#task-input:focus {
  border-color: #007bff;
  outline: none;
}

#task-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.task-item {
  background: #ffffff;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  border-radius: 4px;
  padding: 0.75rem;
  margin: 0.5rem 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.task-options {
  display: flex;
  gap: 10px;
  color: #007bff;
  cursor: pointer;
}

.task-options span:hover {
  text-decoration: underline;
}

/* Dark mode */
body.dark-mode {
  background-color: #2c2c2c;
  color: #e0e0e0;
}

body.dark-mode .main-box {
  background: #333333;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}

body.dark-mode .box {
  background: #333333;
}

body.dark-mode h1 {
  color: #e0e0e0;
}

body.dark-mode .add-btn {
  background-color: #007bff;
  color: #ffffff;
}

body.dark-mode .add-btn:hover {
  background-color: #0056b3;
}

body.dark-mode .toggle-button {
  background-color: #5a6268;
}

body.dark-mode .toggle-button:hover {
  background-color: #6c757dc0;
}

body.dark-mode #task-input {
  border: 1px solid #555;
  background: #666;
  color: #e0e0e0;
}

body.dark-mode #task-input:focus {
  border-color: #007bff;
}

body.dark-mode .task-item {
  background: #555555;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

body.dark-mode .task-options {
  color: #007bff;
}

body.dark-mode .task-options span:hover {
  text-decoration: underline;
}