/* 响应式增强样式 */
.container { max-width: 1200px; margin: 0 auto; padding: 0 1rem; }

/* 按钮样式 */
.btn {
  display: inline-block;
  padding: 0.8rem 1.5rem;
  background: var(--primary-color);
  color: white;
  text-decoration: none;
  border-radius: 4px;
  transition: all 0.3s;
}

.btn:hover {
  opacity: 0.9;
  transform: translateY(-2px);
}

/* 返回顶部按钮 */
#backToTop {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--primary-color);
  color: white;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  border: none;
  cursor: pointer;
  display: none;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  box-shadow: 0 4px 8px rgba(0,0,0,0.2);
  transition: all 0.3s;
  z-index: 1000;
}

#backToTop:hover {
  transform: translateY(-4px);
  box-shadow: 0 6px 12px rgba(0,0,0,0.3);
}

#backToTop.show {
  display: flex;
}

/* 平滑滚动 */
html {
  scroll-behavior: smooth;
}

/* 链接样式 */
a {
  transition: color 0.3s;
}

/* 响应式表格 */
@media (max-width: 768px) {
  table {
    display: block;
    overflow-x: auto;
  }

  #backToTop {
    bottom: 1rem;
    right: 1rem;
    width: 40px;
    height: 40px;
    font-size: 1.2rem;
  }
}