* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-box-sizing: border-box;
    /* 推荐添加，以避免计算宽度时出现偏差 */
    -webkit-user-select: none;
    /*谷歌 /Chrome*/
    -moz-user-select: none;
    /*火狐/Firefox*/
    -ms-user-select: none;
    /*IE 10+*/
    user-select: none;
    line-height: 1;
}
/* 1. 统一盒模型：宽高包含 padding 与 border */
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* 2. 根元素高度占满，避免页面塌陷 */
html,
body {
  height: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  -webkit-font-smoothing: antialiased;   /* macOS 字体平滑 */
  -moz-osx-font-smoothing: grayscale;    /* Firefox 字体平滑 */
}

/* 3. 媒体元素块级化 + 自适应宽度 */
img,
picture,
video,
canvas,
svg {
  display: block;
   height: auto;
  vertical-align: middle;
  border: none;
}

/* 4. 表单控件继承字体，避免强制样式 */
input,
button,
textarea,
select {
 font-family: inherit;
  font-size: inherit;
  line-height: inherit;
  color: inherit;
  background-color: transparent;
  border: none;
  padding: 0;
  margin: 0;
  outline: none;
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
}
/* 禁用状态样式 */
button:disabled,
input:disabled,
select:disabled,
textarea:disabled {
  cursor: not-allowed; /* 禁用时禁止光标 */
  opacity: 0.6; /* 透明度降低，视觉区分 */
}
input:focus,
textarea:focus,
button:focus,
select:focus {
    outline: none;
    outline-offset: 0;
}

/* 5. 移除列表默认标记 */
ul,
ol ,li{
  list-style: none;
   text-decoration: none;
    /* 去除下划线 */
}

/* 6. 链接去除下划线，颜色继承（可按需调整） */
a {
  text-decoration: none;
  color: inherit;
   outline: none;
}

/* 7. 按钮重置背景与边框，保留指针手势 */
button {
  cursor: pointer;
}
textarea {
  resize: none; /* 禁止拉伸，按需开启 */
}
/* 9. 表格：合并边框，清零内边距 */
table {
  border-collapse: collapse;
  border-spacing: 0;
  width: 100%;
}
th, td {
  padding: 0;
  text-align: left;
  border: none;
}

/* 10. 其他清理 */
address, cite, dfn, em, var {
  font-style: normal;
}
code, kbd, samp, pre {
  font-family: 'Courier New', Courier, monospace;
}
small {
  font-size: 100%;
}
blockquote, q {
  quotes: none;
}
blockquote::before, blockquote::after,
q::before, q::after {
  content: '';
}
h1,
h2,
h3,
h4,
h5,
h6 {
   font-size: inherit;
    font-weight: normal
}
input[type=button],
button {
    -webkit-appearance: none;
    -webkit-user-select: none;
}



/* 清除浮动 在需要清除浮动的父元素上添加class="clearfix" */
.clearfix::after {
  content: "";
  display: table;
  clear: both;
}