/* 主题颜色 */
:root {
    --work-color: #ff6b6b;
    --break-color: #6bff95;
  }
  
  body {
    transition: background-color 0.5s ease;
  }
  
  /* 模式选择按钮 */
  .btn-mode {
    width: 80%;
    padding: 15px;
    margin: 10px;
    border-radius: 25px;
    border: 2px solid #ddd;
    background: white;
    transition: all 0.3s ease;
  }
  
  .btn-mode.active {
    background: var(--work-color);
    color: white;
    border-color: var(--work-color);
  }
  
  /* 计时器显示 */
  .timer-display {
    margin: 40px 0;
  }
  
  .timer-display h1 {
    font-size: 6rem;
    font-weight: 700;
  }
  
  /* 控制按钮 */
  .btn-control {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    margin: 0 10px;
    background: white;
    border: 2px solid #ddd;
    transition: all 0.3s ease;
  }
  
  .btn-control:hover {
    transform: scale(1.1);
  }
  
  /* 完成统计 */
  .pomodoro-count {
    font-size: 24px;
    color: var(--work-color);
  }
  
  .completed {
    margin: 0 5px;
  }
  
  /* 响应式调整 */
  @media (max-width: 768px) {
    .timer-display h1 {
      font-size: 4rem;
    }
    
    .btn-mode {
      width: 90%;
    }
  }