/* Document
   ========================================================================== */

/**
 * 1. Correct the line height in all browsers.
 * 2. Prevent adjustments of font size after orientation changes in iOS.
 */

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  -ms-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

/* Sections
   ========================================================================== */

/**
 * Remove the margin in all browsers.
 */

body {
  margin: 0;
  line-height: 1.4;
  font-family: -apple-system, system-ui, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, sans-serif, BlinkMacSystemFont, Helvetica Neue, PingFang SC, Hiragino Sans GB, Microsoft YaHei, Arial;
  background-color: #fff;
}

/**
 * Render the `main` element consistently in IE.
 */

main {
  display: block;
}

/**
 * Correct the font size and margin on `h1` elements within `section` and
 * `article` contexts in Chrome, Firefox, and Safari.
 */

h1 {
  font-size: 2em;
  margin: 0.67em 0;
}

/* Grouping content
   ========================================================================== */

/**
 * 1. Add the correct box sizing in Firefox.
 * 2. Show the overflow in Edge and IE.
 */

hr {
  box-sizing: content-box;
  /* 1 */
  height: 0;
  /* 1 */
  overflow: visible;
  /* 2 */
}

/**
 * 1. Correct the inheritance and scaling of font size in all browsers.
 * 2. Correct the odd `em` font sizing in all browsers.
 */

pre {
  font-family: monospace, monospace;
  /* 1 */
  font-size: 1em;
  /* 2 */
}

/* Text-level semantics
   ========================================================================== */

/**
 * Remove the gray background on active links in IE 10.
 */

a {
  color: #000;
  text-decoration: none;
  background-color: transparent;
  /* 移动端：禁用点击高亮（iOS/Android） */
  -webkit-tap-highlight-color: transparent;
}

/**
 * 1. Remove the bottom border in Chrome 57-
 * 2. Add the correct text decoration in Chrome, Edge, IE, Opera, and Safari.
 */

abbr[title] {
  border-bottom: none;
  /* 1 */
  text-decoration: underline;
  /* 2 */
  text-decoration: underline dotted;
  /* 2 */
}

/**
 * Add the correct font weight in Chrome, Edge, and Safari.
 */

b,
strong {
  font-weight: bolder;
}

/**
 * 1. Correct the inheritance and scaling of font size in all browsers.
 * 2. Correct the odd `em` font sizing in all browsers.
 */

code,
kbd,
samp {
  font-family: monospace, monospace;
  /* 1 */
  font-size: 1em;
  /* 2 */
}

/**
 * Add the correct font size in all browsers.
 */

small {
  font-size: 80%;
}

/**
 * Prevent `sub` and `sup` elements from affecting the line height in
 * all browsers.
 */

sub,
sup {
  font-size: 75%;
  line-height: 0;
  position: relative;
  vertical-align: baseline;
}

sub {
  bottom: -0.25em;
}

sup {
  top: -0.5em;
}

/* Embedded content
   ========================================================================== */

/**
 * Remove the border on images inside links in IE 10.
 */

img {
  border-style: none;
}

/* Forms
   ========================================================================== */

/**
 * 1. Change the font styles in all browsers.
 * 2. Remove the margin in Firefox and Safari.
 */

button,
input,
optgroup,
select,
textarea {
  font-family: inherit;
  /* 1 */
  font-size: 100%;
  /* 1 */
  line-height: 1.15;
  /* 1 */
  margin: 0;
  /* 2 */
}

/**
 * Show the overflow in IE.
 * 1. Show the overflow in Edge.
 */

button,
input {
  /* 1 */
  overflow: visible;
}

/**
 * Remove the inheritance of text transform in Edge, Firefox, and IE.
 * 1. Remove the inheritance of text transform in Firefox.
 */

button,
select {
  /* 1 */
  text-transform: none;
}

/**
 * Correct the inability to style clickable types in iOS and Safari.
 */

button,
[type="button"],
[type="reset"],
[type="submit"] {
  -webkit-appearance: button;
}

/**
 * Remove the inner border and padding in Firefox.
 */

button::-moz-focus-inner,
[type="button"]::-moz-focus-inner,
[type="reset"]::-moz-focus-inner,
[type="submit"]::-moz-focus-inner {
  border-style: none;
  padding: 0;
}

/**
 * Restore the focus styles unset by the previous rule.
 */

button:-moz-focusring,
[type="button"]:-moz-focusring,
[type="reset"]:-moz-focusring,
[type="submit"]:-moz-focusring {
  outline: 1px dotted ButtonText;
}

/**
 * Correct the padding in Firefox.
 */

fieldset {
  padding: 0.35em 0.75em 0.625em;
}

/**
 * 1. Correct the text wrapping in Edge and IE.
 * 2. Correct the color inheritance from `fieldset` elements in IE.
 * 3. Remove the padding so developers are not caught out when they zero out
 *    `fieldset` elements in all browsers.
 */

legend {
  box-sizing: border-box;
  /* 1 */
  color: inherit;
  /* 2 */
  display: table;
  /* 1 */
  max-width: 100%;
  /* 1 */
  padding: 0;
  /* 3 */
  white-space: normal;
  /* 1 */
}

/**
 * Add the correct vertical alignment in Chrome, Firefox, and Opera.
 */

progress {
  vertical-align: baseline;
}

/**
 * Remove the default vertical scrollbar in IE 10+.
 */

textarea {
  overflow: auto;
}

/**
 * 1. Add the correct box sizing in IE 10.
 * 2. Remove the padding in IE 10.
 */

[type="checkbox"],
[type="radio"] {
  box-sizing: border-box;
  /* 1 */
  padding: 0;
  /* 2 */
}

/**
 * Correct the cursor style of increment and decrement buttons in Chrome.
 */

[type="number"]::-webkit-inner-spin-button,
[type="number"]::-webkit-outer-spin-button {
  height: auto;
}

/**
 * 1. Correct the odd appearance in Chrome and Safari.
 * 2. Correct the outline style in Safari.
 */

[type="search"] {
  -webkit-appearance: textfield;
  /* 1 */
  outline-offset: -2px;
  /* 2 */
}

/**
 * Remove the inner padding in Chrome and Safari on macOS.
 */

[type="search"]::-webkit-search-decoration {
  -webkit-appearance: none;
}

/**
 * 1. Correct the inability to style clickable types in iOS and Safari.
 * 2. Change font properties to `inherit` in Safari.
 */

::-webkit-file-upload-button {
  -webkit-appearance: button;
  /* 1 */
  font: inherit;
  /* 2 */
}

/* Interactive
   ========================================================================== */

/*
 * Add the correct display in Edge, IE 10+, and Firefox.
 */

details {
  display: block;
}

/*
 * Add the correct display in all browsers.
 */

summary {
  display: list-item;
}

/* Misc
   ========================================================================== */

/**
 * Add the correct display in IE 10+.
 */

template {
  display: none;
}

/**
 * Add the correct display in IE 10.
 */

[hidden] {
  display: none;
}

/**
 * 头部
 */

header {
  position: sticky;
  top: 0;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.5rem 3rem;
  background-color: #fff;
  z-index: 9;
  box-sizing: border-box;
}

header .logo {
  font-size: 1.2rem;
  color: #409EFF;
}

header nav a {
  font-size: 0.8rem;
  margin-left: 2rem;
}

header nav a:hover {
  color: #409EFF;
}

header nav a.active, .m-nav a.active {
  color: #409EFF;
  font-weight: bold;
}

header .m-nav-icon {
  display: none;
}

.m-nav {
  display: none;
  position: fixed;
  top: 3.5rem;
  bottom: 0;
  width: 100%;
  padding: 10px;
  overflow-y: auto;
  background-color: rgba(255, 255, 255, .95);
  box-sizing: border-box;
  z-index: 1;
}

header .nav-btn {
  position: relative;
  width: 1.3rem;
  height: 1.3rem;
  cursor: pointer;
}

header .nav-btn .line {
  width: 100%;
  height: 2px;
  position: absolute;
  left: 0;
  transition: all .2s;
  transform-origin: center;
  background-color: #383838;
}

.nav-btn .line1 {
  top: 0;
}

.nav-btn .line2 {
  top: 50%;
  margin-top: -1px;
}

.nav-btn .line3 {
  bottom: 0;
}

.nav-btn.on .line {
  top: 50%;
  bottom: auto;
  margin-top: -1px;
}

.nav-btn.on .line1 {
  transform: rotate(45deg);
}

.nav-btn.on .line2 {
  opacity: 0;
  filter: alpha(opacity=0);
}

.nav-btn.on .line3 {
  transform: rotate(-45deg);
}

.m-nav ul {
  margin: 0;
  padding: 0;
  font-size: 0.9rem;
  list-style: none outside none;
}

.m-nav ul li {
  border-bottom: 1px solid #dcdcdc;
}

.m-nav ul li a {
  position: relative;
  display: block;
  padding: 0.7rem;
}

/**
* 尾部
*/

footer {
  font-size: 0.8rem;
  padding: 1rem 3rem;
}

footer p {
  margin: 0.6rem 0;
}

footer .company {
  font-size: 1rem;
  font-weight: bold;
}

#ipc {
  margin-top: 50px;
  text-align: center;
}

@media (max-width: 767px) {
  header {
    padding: 1rem;
  }

  header nav {
    display: none;
  }

  header .m-nav-icon {
    display: block;
  }
}

@media (min-width: 768px) {
  html {
    font-size: 17px;
  }
}

@media (min-width: 992px) {
  html {
    font-size: 18px;
  }
}

@media (min-width: 1200px) {
  html {
    font-size: 19px;
  }
}

@media (min-width: 1400px) {
  html {
    font-size: 20px;
  }
}