lours.net/user/themes/le_style_de_lours_modif/scss/theme/_header.scss

.background{
  position: absolute;
  top: 0;
  width: 100%;
  left: 0;
  display: inline-flex;
  & > div {
    width: 55%;
    display: inline-block;
    position: relative;
    padding-bottom: 100%;
    vertical-align: middle;
  }
  .fond-g{
    svg{
      width: 110%;
      display: inline-block;
      position: absolute;
      top: 0;
      left: 0;
    }
  }
  .fond-d{
    svg{
      width: 110%;
      display: inline-block;
      position: absolute;
      top: 0;
      right: 0;
    }
  }
}

.background-footer{
  z-index: -1;
  position: absolute;
  bottom: 0;
  width: 100%;
  left: 0;
  display: inline-flex;
  & > div {
    width: 55%;
    display: inline-block;
    position: relative;
    padding-bottom: 100%;
    vertical-align: middle;
  }
  .fond-g{
    svg{
      width: 110%;
      display: inline-block;
      position: absolute;
      bottom: 0;
      left: 0;
    }
  }
  .fond-d{
    svg{
      width: 110%;
      display: inline-block;
      position: absolute;
      bottom: 0;
      right: 0;
    }
  }
}

header{
  z-index: 999;
  position: relative;
  nav{
    z-index: 999;
    position: fixed;
    right: 50px;
    top: 2px;
    ul{
      text-align: right;
      li{
        text-transform: uppercase;
        display: inline-block;
        margin-left: 10px;
      }
    }
  }
  .title{
    transition: background 1s;
    background: none;
    z-index: 998;
    position: fixed;
    width: auto;
    left: 0px;
    right: 0px;
    padding: 20px 50px 0 50px;
    .filet{
      z-index: -1;
      width: auto;
      height: 2px;
      background: black;
      position: absolute;
      top: 65px;
      left: 0px;
      right: 0px;
    }
    text-align: center;
    h1{
      margin-top: 0px;
      white-space:nowrap;
       z-index: 1;
       display: inline-flex;
       width: 100%;
       align-items: center;
       &::after{
         right: 0;
         content: " ";
         width: 50%;
         height: 0px;
         border: 1px solid $blue;
         margin-left: 20px;
       }
       &::before{
         left: 0;
         content: " ";
         width: 50%;
         height: 0px;
         border: 1px solid $blue;
         margin-right: 20px;
       }

    }
    &.Hc{
      background: white;
      transition: background 1s;
    }
  }
  .logo{
    margin: 150px 0 50px 0;
    width: 100%;
    display: inline-flex;
    justify-content: space-around;
    align-items: center;
    & > div{
      width: calc(100% / 3);
      min-width: 300px;
      margin-left: 100px;
    }
    & > svg{
      width: calc(100% / 3);
      min-width: 300px;
      margin: 0 30px;
      height: 300px;
     }
     & > section{
       width: calc(100% / 3);
       min-width: 300px;
       margin-right: 100px;
     }
    #user{
      div{
        text-align: right;
        p{
          margin:0px;
        }
      }
    }
    .why_lsdo{
      display: inline-flex;
      flex-direction: column;
      position: relative;
      h3{
        z-index: 1;
        position: absolute;
        cursor: pointer;
        margin: 0;
        transform: rotate(-15deg) translateY(0px);
      }
      section{
        position: absolute;
        padding: 0 10px;
        opacity: 0;
        top: -130px;
        height: 300px;
        overflow: auto;
        p{
          pointer-events: none;
        }
        &.open{
          display: block!important;
        }
      }
      &>svg{
        width: 100px;
        height: 20px;
        position: absolute;
        transform: rotate(-15deg) translateY(50px);
      }

    }
  }
}