:root {
  --primary: #646cff;
  --bg: #f9f9f9;
  --card: #ffffff;
  --text: #213547;
  --danger: #ff4d4f;
}

html,
body {
  margin: 0;
  padding: 0;
}
body {
  color: var(--text);
  font-family:
    Inter,
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    'Segoe UI',
    Roboto,
    Oxygen,
    Ubuntu,
    Cantarell,
    'Open Sans',
    'Helvetica Neue',
    Avenir,
    Helvetica,
    Arial,
    sans-serif;
  background-color: var(--bg);
  display: flex;
  justify-content: center;
  min-height: 100vh;
}

.app-container {
  width: 100%;
  max-width: 500px;
  padding: 2rem;
}

h1 {
  margin: 0;
  font-size: 2.5rem;
  background: linear-gradient(to right, #646cff, #ff6b6b);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

p {
  color: #888888;
  margin-top: 0.5rem;
}

.input-group {
  display: flex;
  gap: 10px;
  margin-bottom: 1.5rem;
}

input[type='text'] {
  flex: 1;
  padding: 12px;
  border: 1px solid #ddd;
  border-radius: 8px;
  font-size: 1rem;
  outline: none;
  transition: border-color 0.2s;

  &:focus {
    border-color: var(--primary);
  }
}

button {
  padding: 10px 20px;
  border: none;
  border-radius: 8px;
  background-color: var(--primary);
  color: white;
  font-weight: 600;
  cursor: pointer;
  transition:
    opacity 0.2s,
    background-color 0.48s;

  &.not-allow {
    cursor: unset;
    background-color: #9696aa;
  }

  &:not(.not-allow):hover {
    opacity: 0.9;
  }
}

.todo-list-container {
  background: var(--card);
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
  overflow: hidden;
}

.filters {
  padding: 1rem;
  border-bottom: 1px solid #eee;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.9rem;
  background: #fafafa;

  .buttons button {
    background: transparent;
    color: #888888;
    padding: 5px 10px;
    margin: 0 2px;

    &.active {
      color: var(--primary);
      cursor: unset;
      background: rgba(100, 108, 255, 0.1);
    }
  }
}

.clear-btn {
  background: transparent;
  color: var(--danger);
  font-size: 0.8rem;
  padding: 5px;
}

.list {
  padding: 1rem;
  min-height: 200px;
}

.todo-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px;
  border-bottom: 1px solid #f0f0f0;
  transition: all 0.2s;

  &:last-child {
    border-bottom: none;
  }

  &.completed .todo-content span {
    text-decoration: line-through;
    color: #aaaaaa;
  }

  &:hover .delete-btn {
    opacity: 1;
  }
}

.todo-content {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  flex: 1;

  span {
    font-size: 1.1rem;
  }
}

.delete-btn {
  background: transparent;
  color: #ff4d4f;
  font-size: 1.5rem;
  padding: 0px 10px;
  opacity: 0;
  transition: opacity 0.2s;
}

.empty-state {
  text-align: center;
  color: #cccccc;
  padding: 2rem;
}