body {
  background: #f4f4f4;
  font-family: Arial, sans-serif;
}

.todo-container {
  background: #fff;
  max-width: 400px;
  margin: 40px auto;
  padding: 24px;
  border-radius: 12px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.12);
}

h1 {
  text-align: center;
  color: #333;
  margin-bottom: 20px;
}

#new-task {
  width: 65%;
  padding: 10px;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-size: 16px;
  margin-right: 8px;
}

#add-btn {
  padding: 10px 18px;
  background: linear-gradient(90deg, #007bff 60%, #00c6ff 100%);
  color: #fff;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: 16px;
  transition: background 0.2s;
}

#add-btn:hover {
  background: linear-gradient(90deg, #0056b3 60%, #007bff 100%);
}

#task-list {
  list-style: none;
  padding: 0;
  margin-top: 24px;
}

#task-list li {
  background: #f9f9f9;
  margin-bottom: 10px;
  padding: 12px 16px;
  border-radius: 6px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 16px;
  box-shadow: 0 1px 4px rgba(0,0,0,0.05);
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}

#task-list li.completed {
  text-decoration: line-through;
  color: #888;
  background: #e0e0e0;
}

#delete-completed-btn {
  display: block;
  width: 100%;
  margin: 24px 0 0 0;
  padding: 12px 0;
  background: linear-gradient(90deg, #ff4e50 60%, #f9d423 100%);
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: 16px;
  font-weight: bold;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(255,78,80,0.08);
  transition: background 0.2s;
}

#delete-completed-btn:hover {
  background: linear-gradient(90deg, #c0392b 60%, #f9d423 100%);
}

.footer {
  margin-top: 32px;
  padding: 18px 0 8px 0;
  text-align: center;
  background: #f4f4f4;
  border-top: 1px solid #e0e0e0;
}

.github-link {
  display: inline-flex;
  align-items: center;
  color: #24292e;
  background: linear-gradient(90deg, #f9d423 0%, #ff4e50 100%);
  padding: 10px 24px;
  border-radius: 6px;
  font-size: 16px;
  font-weight: bold;
  text-decoration: none;
  box-shadow: 0 2px 8px rgba(255,78,80,0.08);
  transition: background 0.2s, color 0.2s;
}

.github-link:hover {
  background: linear-gradient(90deg, #ff4e50 0%, #f9d423 100%);
  color: #fff;
}

@media (max-width: 500px) {
  .todo-container {
    max-width: 98vw;
    padding: 12px;
    border-radius: 8px;
  }
  #new-task {
    width: 100%;
    margin-bottom: 8px;
    margin-right: 0;
  }
  #add-btn {
    width: 100%;
    margin-bottom: 12px;
  }
}