:root {
  --bg: #ffffff;
  --text: #333;
  --task-bg: #f4f0fa;
  --accent: #7b2cbf;
  --danger: #ff6b6b;
  --input-bg: #fff;
}

body.dark {
  --bg: #1e1e2f;
  --text: #f1f1f1;
  --task-bg: #2a2a40;
  --accent: #c77dff;
  --danger: #ef476f;
  --input-bg: #2a2a40;
}

body {
  font-family: 'Poppins', sans-serif;
  background: linear-gradient(to right, #fbc2eb, #a6c1ee);
  margin: 0;
  padding: 0;
  background-color: var(--bg);
  color: var(--text);
  transition: all 0.3s ease;
}

.container {
  max-width: 500px;
  margin: 80px auto;
  background-color: var(--bg);
  padding: 30px 25px;
  border-radius: 15px;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.1);
  transition: background-color 0.3s ease;
}

.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

h2 {
  margin: 0;
}

#theme-toggle {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--accent);
}

.input-container {
  display: flex;
  gap: 10px;
  margin: 20px 0;
}

input[type="text"] {
  flex: 1;
  padding: 12px;
  background-color: var(--input-bg);
  border: 1px solid #ddd;
  border-radius: 8px;
  font-size: 1rem;
  color: var(--text);
}

button {
  background-color: var(--accent);
  color: white;
  border: none;
  padding: 12px 18px;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

button:hover {
  background-color: #5a189a;
}

ul {
  list-style-type: none;
  padding: 0;
}

ul li {
  background-color: var(--task-bg);
  padding: 14px;
  margin-bottom: 10px;
  border-radius: 10px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  animation: fadeIn 0.3s ease;
}

ul li span {
  flex: 1;
  cursor: pointer;
  word-break: break-word;
}

ul li.completed span {
  text-decoration: line-through;
  color: #aaa;
}

.delete-btn,
.edit-btn {
  background-color: var(--danger);
  color: white;
  border: none;
  padding: 6px 10px;
  border-radius: 6px;
  font-size: 0.85rem;
  cursor: pointer;
  margin-left: 8px;
  transition: background-color 0.2s ease;
}

.edit-btn {
  background-color: #6c757d;
}

.edit-btn:hover {
  background-color: #495057;
}

.delete-btn:hover {
  background-color: #d62828;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 600px) {
  .container {
    margin: 50px 20px;
    padding: 20px;
  }
}