* {
  box-sizing: border-box;
}

:root {
  --bg: #1a0a2e;
  --container-bg: #2d1045;
  --primary: #c850c0;
  --primary-hover: #e040fb;
  --accent: #ff6eb4;
  --text: #f8e8ff;
  --text-muted: #d0a8f0;
  --task-bg: #3d1a5c;
  --task-completed-bg: #2a1040;
  --border: #7c3fa0;
  --delete-color: #ff6eb4;
  --shadow: rgba(200, 80, 192, 0.3);
}

body {
  margin: 0;
  padding: 1rem;
  font-family: system-ui, sans-serif;
  background-color: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

.container {
  max-width: 640px;
  margin: 2rem auto;
  background: var(--container-bg);
  border-radius: 16px;
  padding: 2rem;
  box-shadow: 0 0 32px var(--shadow);
}

h1 {
  text-align: center;
  color: var(--accent);
  font-size: 2rem;
  margin-bottom: 0.25rem;
  letter-spacing: 1px;
}

.version-label {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: 1.5rem;
  font-style: italic;
}

.input-area {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.input-area input {
  flex: 1;
  min-width: 0;
  padding: 0.75rem 1rem;
  border-radius: 8px;
  border: 2px solid var(--border);
  background: var(--task-bg);
  color: var(--text);
  font-size: 1rem;
  outline: none;
}

.input-area input:focus {
  border-color: var(--primary);
}

.input-area button {
  padding: 0.75rem 1.25rem;
  border-radius: 8px;
  border: none;
  background: var(--primary);
  color: #fff;
  font-size: 1rem;
  cursor: pointer;
  font-weight: 600;
  transition: background 0.2s;
}

.input-area button:hover {
  background: var(--primary-hover);
}

#taskList {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.task-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--task-bg);
  border-radius: 10px;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border);
  transition: background 0.2s;
}

.task-item.completed {
  background: var(--task-completed-bg);
  opacity: 0.75;
}

.task-item .task-title {
  flex: 1;
  font-size: 1rem;
  word-break: break-word;
}

.task-item.completed .task-title {
  text-decoration: line-through;
  color: var(--text-muted);
}

.task-item button.toggle-btn {
  padding: 0.4rem 0.75rem;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  font-size: 0.8rem;
  font-weight: 600;
  background: var(--primary);
  color: #fff;
  transition: background 0.2s;
  white-space: nowrap;
}

.task-item button.toggle-btn:hover {
  background: var(--primary-hover);
}

.task-item button.toggle-btn.completed {
  background: var(--text-muted);
  color: var(--container-bg);
}

.task-item button.delete-btn {
  padding: 0.4rem 0.6rem;
  border-radius: 6px;
  border: 1px solid var(--delete-color);
  background: transparent;
  color: var(--delete-color);
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 700;
  transition: background 0.2s, color 0.2s;
}

.task-item button.delete-btn:hover {
  background: var(--delete-color);
  color: #fff;
}

.footer-watermark {
  text-align: center;
  margin-top: 2rem;
  color: var(--text-muted);
  font-size: 0.75rem;
  opacity: 0.8;
}

@media (max-width: 480px) {
  .input-area {
    flex-direction: column;
  }

  .input-area input,
  .input-area button {
    width: 100%;
  }

  .container {
    margin: 1rem auto;
    padding: 1.25rem;
  }
}