:root {
  --bg: #1f1f2e;
  --bg-container: #292944;
  --text: #fff;
  --highlight: #ffc107;
  --task-bg: #393960;
  --completed-bg: #2e7d32;
  --search-bg: #f1f1f1;
  --btn-color: #4caf50;
  --btn-hover: #45a049;
}

body.light-mode {
  --bg: #f9f9f9;
  --bg-container: #ffffff;
  --text: #1a1a1a;
  --highlight: #ff9800;
  --task-bg: #eaeaea;
  --completed-bg: #c8e6c9;
  --search-bg: #ffffff;
  --btn-color: #2196f3;
  --btn-hover: #1976d2;
}

body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background-color: var(--bg);
  color: var(--text);
  display: flex;
  justify-content: center;
  padding: 2rem;
  transition: 0.3s;
}

.container {
  width: 100%;
  max-width: 600px;
  background-color: var(--bg-container);
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 0 20px rgba(0,0,0,0.3);
}

h1 {
  text-align: center;
  color: var(--highlight);
  margin-bottom: 1.5rem;
}

form, .controls {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

form input, select, button, #search-input {
  padding: 0.75rem;
  font-size: 1rem;
  border: none;
  border-radius: 8px;
}

#task-input, #task-due, #priority-select, #search-input {
  background-color: var(--search-bg);
  color: var(--text);
}

form button, .controls button {
  background-color: var(--btn-color);
  color: #fff;
  cursor: pointer;
  transition: background 0.3s ease;
}

form button:hover, .controls button:hover {
  background-color: var(--btn-hover);
}

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

.task {
  background-color: var(--task-bg);
  padding: 1rem;
  border-radius: 10px;
  margin-bottom: 1rem;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
}

.task.completed {
  background-color: var(--completed-bg);
  text-decoration: line-through;
  color: #aaa;
}

.task-content {
  flex-grow: 1;
}

.task-content input[type="checkbox"] {
  margin-right: 0.5rem;
  transform: scale(1.2);
}

.task-date {
  font-size: 0.85rem;
  color: #ccc;
}

.priority-high { color: #ff5252; font-weight: bold; }
.priority-medium { color: #ffc107; font-weight: bold; }
.priority-low { color: #81c784; font-weight: bold; }

.task-actions button {
  background: transparent;
  color: inherit;
  border: none;
  margin-left: 0.5rem;
  cursor: pointer;
}

.task-actions button:hover {
  color: var(--highlight);
}