project-codepen/src/components/Header.css

body{
    margin:0;
}
  
nav {
    display: flex;
    margin-bottom: 30px;
    padding: 5px;
    background: linear-gradient(#a088bd, #c7a9aa);
}

.img_logo {
    width: 100px;
    margin-right: 1035px;
    border: 1.5px solid rgb(72, 70, 75);
    margin-top: 10px;
    margin-left: 15px;
}

.img_logo:hover {
    border: 1.5px solid rgb(231, 224, 224);
    width: 99px;
}

.logaut a {
    color: rgb(23, 6, 39);
    text-decoration: none;
    font-size: 20px;
}

.logaut button {
    position: relative;
    display: inline-block;
    width: 6.5em;
    height: 2.5em;
    cursor: pointer;
    margin-top: 7px;
    margin-bottom: 5px;
    vertical-align: middle;
    font-weight: 550;
    text-align: center;
    text-decoration: none;
    user-select: none;
    color: rgb(41, 14, 66);
    outline: none;
    border: 1px solid rgba(110,121,128,.8);
    border-top-color: rgba(0,0,0,.3);
    border-radius: 5px;
    background: rgb(206, 220, 231) linear-gradient(rgb(206,220,231), rgb(106, 70, 148));
    box-shadow:
     0 -1px rgba(10,21,28,.9) inset,
     0 1px rgba(255,255,255,.5) inset;
}

.logaut button:hover {
    background: linear-gradient(#baa7cc, #9285b4);
} 

.avatar {
   margin-top: 25px;
   margin-right: 10px;
   width: 70px;
   height: 70px;
}

.button_search {
    cursor: pointer;
    margin-top: 50px;
    margin-right: 10px;
    position: relative;
    display: inline-block;
    width: 6.5em;
    height: 2.5em;
    margin-bottom: 5px;
    vertical-align: middle;
    font-weight: 550;
    text-align: center;
    text-decoration: none;
    user-select: none;
    color: rgb(41, 14, 66);
    outline: none;
    border: 1px solid rgba(110,121,128,.8);
    border-top-color: rgba(0,0,0,.3);
    border-radius: 5px;
    background: rgb(206, 220, 231) linear-gradient(rgb(206,220,231), rgb(106, 70, 148));
    box-shadow:
     0 -1px rgba(10,21,28,.9) inset,
     0 1px rgba(255,255,255,.5) inset;
}

.button_search:hover {
    background: linear-gradient(#baa7cc, #9285b4);
}