* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: Helvetica, "PingFang SC", "Microsoft Yahei", sans-serif;
  font-size: 14px;
}
a {
  text-decoration: none;
}
img {
  width: 100%;
}

:root {
  --primary-color: #2d6bff;
  --secondary-color: #e3e3e3;
  --text-color-lightest: #e7e9ec;
  --text-color-darker: #2e2e2e;
  --text-color-dark: #494949;
  --text-color-gray: #444444;
  --text-color-dark-gray: #727272;
  --text-color-light-gray: #c6c6c6;
  --mask-color: rgba(42, 42, 42, 0.69);
}

header {
  width: 100vw;
  height: 80px;
  display: grid;
  padding: 0 40px;
  grid-template-columns: 1fr 2fr;
  align-items: center;
  position: relative;
  z-index: 200;
}
header .logo {
  font-size: 24px;
  font-weight: 600;
  color: #fff;
}

header nav {
  justify-self: end;
}
header nav a {
  color: #fff;
  font-size: 16px;
  margin: 0 24px;
}

header nav a.active {
  color: var(--primary-color);
  position: relative;
}

header nav a.active::after {
  content: "";
  display: inline-block;
  width: 80%;
  height: 2px;
  border-radius: 1px;
  transform: translateY(8px);
  background-color: var(--primary-color);
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  bottom: 0;
  margin: auto;
}

header .burger {
  display: none;
}
.burger-line1 {
  transform-origin: center center;
}

/* 页面下滑时固定导航，背景设置为白色 */
header.sticky {
  position: fixed;
  background-color: white;
  box-shadow: 0 0 18px rgba(0, 0, 0, 0.2);
  animation: dropDown 0.5s ease-in-out forwards;
}

/* 固定导航文字颜色为黑色 */
header.sticky .logo,
header.sticky nav a,
header.sticky nav i {
  color: var(--text-color-darker);
}

@keyframes dropDown {
  from {
    transform: translateY(-80px);
  }
  to {
    transform: translateY(0);
  }
}

.banner {
  position: relative;
  top: -80px;
  z-index: 50;
}
.banner-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
}

.banner-wrap .banner-img {
  object-fit: cover;
  width: 100vw;
  height: 40vh;
}
.banner-content {
  position: absolute;
  z-index: 70;
  color: #fff;
  text-align: center;
  max-width: 60vw;
}

.banner-content h1 {
  font-size: 54px;
  font-weight: 600;
}

.banner-content h3 {
  font-size: 24px;
  margin: 48px 0;
}
.contact-btn {
  padding: 10px 28px;
  background: linear-gradient(150deg, #3ea3f4 0%, #2d6bff 100%);
  border: 0;
  border-radius: 4px;
  color: #fff;
  font-size: 16px;
  cursor: pointer;
  outline: none;
}
.banner-content > * {
  opacity: 0;
}

.banner-mask {
  background: var(--mask-color);
  opacity: 0.5;
  position: absolute;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 60;
}

.content {
  display: flex;
  flex-direction: column;
  align-items: center;
}
.partner {
  position: relative;
}
.partner-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
}

.partner-wrap .partner-img {
  object-fit: cover;
  width: 100vw;
  height: 40vh;
}
.partner-content {
  position: absolute;
  color: #fff;
  text-align: center;
  max-width: 60vw;
}

.partner-content h1 {
  font-size: 34px;
  font-weight: 600;
  margin-bottom: 12px;
}

section {
  display: grid;
  justify-items: center;
  max-width: 1200px;
  padding: 0 40px;
}

.showcases {
  max-width: unset;
  padding: 0;
  margin-bottom: 80px;
}
/* 案例筛选按钮容器 */
.filter-btns {
  margin-bottom: 38px;
}

/* 筛选按钮 */
.filter-btn {
  margin: 0 7px;
  background-color: var(--secondary-color);
  border: 0;
  color: var(--text-color-dark-gray);
  font-size: 20px;
  padding: 12px 28px;
  border-radius: 4px;
  cursor: pointer;
  transition: 0.4s;
}

/* 按钮选中时 */
.filter-btn:focus,
.filter-btn:active {
  /* 去掉边框 */
  outline: none;
}

.filter-btn.active,
.filter-btn:hover {
  background-color: var(--primary-color);
  color: white;
}

.showcases .cases {
  width: 100vw;
}

.showcases .case-item {
  width: 25vw;
  height: 20vw;
  overflow: hidden;
}

/* 案例图片 */
.case-item img {
  height: 100%;
  object-fit: cover;
}

.scrollToTop {
  display: none;
  position: relative;
  z-index: 300;
}

footer {
  background-color: var(--primary-color);
  display: grid;
  justify-items: center;
  padding-top: 72px;
  padding-bottom: 24px;
}

/* 底部菜单 */
.footer-menus {
  width: 100%;
  max-width: 1180px;
  display: grid;
  /* 5列布局 */
  grid-template-columns: 1fr 1fr;
  padding: 0 80px;
  position: relative;
}

/* 导航菜单，靠右对齐 */
.footer-menu {
  justify-self: center;
}

.menu-title {
  font-size: 16px;
  color: white;
  font-weight: 500;
  margin-bottom: 20px;
}

.contact-us {
  justify-self: center;
  color: #fff;
}

.contact-us p:not(:first-child) {
  padding-bottom: 16px;
}

.menu-items li {
  list-style: none;
  padding-bottom: 8px;
}
.menu-items li a {
  text-decoration: none;
  color: #fff;
}

/* 备案信息 */
.icp-info {
  margin-top: 24px;
  margin-bottom: 16px;
}

/* 备案信息，版权信息 */
.icp-info,
.rights {
  font-weight: 300;
  /* 占满整行，-1代表最后一个编号 */
  grid-column: 1 / -1;
  /* 居中对齐 */
  justify-self: center;
  color: white;
}
/* 返回顶部按钮 */
.fixed-btn {
  position: fixed;
  z-index: 3;
  bottom: 60px;
  right: 30px;
  display: flex;
  flex-direction: column;
}
.fixed-btn a,
.fixed-btn button {
  width: 42px;
  height: 42px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--primary-color);
  color: white;
  margin-top: 20px;
  border: 1px solid #fff;
  position: relative;
}
.fixed-btn a img,
.fixed-btn button img {
  width: 24px;
  height: 24px;
}

#comment_bubble {
  height: auto;
  background: #fff;
  position: absolute;
  -moz-border-radius: 12px;
  -webkit-border-radius: 12px;
  border-radius: 12px;
  padding: 15px;
  color: var(--primary-color);
  font-size: 18px;
  display: none;
  left: -162px;
  box-shadow: 0 0 18px rgba(0, 0, 0, 0.2);
  white-space: nowrap;
}

#comment_bubble:before {
  content: "";
  width: 0;
  height: 0;
  left: 100%;
  top: 30%;
  position: absolute;
  border-top: 10px solid transparent;
  border-left: 15px solid #fff;
  border-bottom: 10px solid transparent;
}
@media (max-width: 1100px) {
  header nav {
    display: none;
  }
  header {
    grid-template-columns: repeat(2, 1fr);
  }

  /* 折叠菜单样式，显示出来 */
  header .burger {
    display: block;
    justify-self: end;
    cursor: pointer;
    position: relative;
    width: 20px;
    height: 6px;
  }

  /* 折叠按钮线条样式 */
  .burger-line1,
  .burger-line2,
  .burger-line3 {
    width: 20px;
    height: 2px;
    background-color: var(--text-color-lightest);
    /* position: relative; */
  }

  /* 上移第一条线 */
  .burger-line1 {
    position: absolute;
    top: -6px;
  }
  /* 下移第三条线 */
  .burger-line3 {
    position: absolute;
    top: 6px;
  }

  /* 全屏导航展开时，折叠按钮设置为深色 */
  header.open .burger-line1,
  header.open .burger-line2,
  header.open .burger-line3,
  header.sticky .burger-line1,
  header.sticky .burger-line2,
  header.sticky .burger-line3 {
    background-color: var(--text-color-darker);
    transition: 0.4s ease;
  }

  /* 全屏导航显示时，折叠按钮第一条线样式 */
  header.open .burger-line1 {
    transform: rotate(45deg) translate(3px, 5px);
  }

  /* 全屏导航显示时，折叠按钮第二条线样式 */
  header.open .burger-line2 {
    transform: translateX(5px);
    opacity: 0;
  }

  /* 全屏导航显示时，折叠按钮第三条线样式 */
  header.open .burger-line3 {
    transform: rotate(-45deg) translate(3px, -5px);
  }
  /* 全屏导航显示时，logo样式 */
  header.open .logo {
    color: var(--text-color-darker);
    z-index: 40;
  }

  /* 全屏导航显示时，导航菜单样式 */
  header.open nav {
    display: grid;
    /* 每行高度为内容的高度，不设置会平分全屏高度 */
    grid-auto-rows: max-content;
    /* 菜单项靠右对齐 */
    justify-items: end;
    position: absolute;
    top: 0;
    left: 0;
    background: white;
    width: 100vw;
    height: 100vh;
    padding: 0 40px;
    opacity: 0;
    /* 下滑效果 */
    animation: slideDown 0.6s ease-out forwards;
  }
  /* 全屏导航显示时，导航菜单项样式和动画 */
  header.open nav > * {
    margin: 12px 4px;
    font-size: 18px;
    color: var(--text-color-darker);
    opacity: 0;
    animation: showMenu 0.5s linear forwards 0.4s;
  }

  /* 导航下滑动画 */
  @keyframes slideDown {
    from {
      height: 0;
      opacity: 0;
    }
    to {
      height: 100vh;
      padding-top: 80px;
      opacity: 1;
    }
  }

  /* 菜单项动画 */
  @keyframes showMenu {
    from {
      opacity: 0;
      transform: translateY(-1vh);
    }
    to {
      opacity: 1;
    }
  }

  section {
    padding: 0 40px;
  }
}

/* 小于992像素时 */
@media (max-width: 992px) {
  .banner-content h1 {
    font-size: 48px;
  }

  .banner-content h3 {
    font-size: 18px;
  }

  .showcases .case-item {
    width: calc(100vw / 3);
  }
}

/* 小于768像素时 */
@media (max-width: 768px) {
  .showcases .case-item {
    width: calc(100vw / 2);
    height: 30vw;
  }
  section {
    padding: 0 12px;
  }

  .footer-menus {
    grid-template-columns: 1fr;
    padding: 0 18px;
  }
  .footer-menu,
  .contact-us {
    justify-self: start;
    margin-bottom: 20px;
  }
  .certificate-all img {
    width: 576px;
  }
  .title {
    font-size: 26px;
  }
  .banner-content h1 {
    font-size: 26px;
    margin-top: 100px;
  }
  .banner-content h3 {
    font-size: 12px;
    margin-top: 28px;
  }
  .banner-content .contact-btn {
    padding: 8px 18px;
    font-size: 14px;
  }
  .introduce-name {
    margin-bottom: 8px;
  }
  .introduce-wrap {
    padding: 0 0;
  }
  .partner-content h1 {
    font-size: 26px;
    margin-bottom: 24px;
  }
  .filter-btns {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    padding: 24px 24px 18px;
    margin-bottom: 0;
  }
  .filter-btn {
    font-size: 16px;
    margin-bottom: 12px;
    padding: 6px 14px;
  }
  .content{
    margin-top: -80px;
  }
  footer{
    padding-top: 24px;
  }
  header{
    padding: 0 24px;
  }
  .fixed-btn{
    right: 12px;
  }
}

/* 小于576像素 */
@media (max-width: 576px) {
  section {
    padding: 0 12px;
  }
  .banner-content h1 {
    font-size: 26px;
  }
  .banner-content h3 {
    font-size: 12px;
  }
  .banner-content .contact-btn {
    padding: 8px 18px;
    font-size: 14px;
  }
  .showcases .case-item {
    width: 100vw;
    height: 60vw;
  }
}