html, body {
    margin: 0;
    padding: 0;
    background-color: #f5f5f5;
    font-family: "Source Sans 3", sans-serif;

}

header{
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 67px;
    background-color: #ffffff;
    border-bottom: 2px solid #c6c6c698;
    padding-bottom: 5px;

}

.logo,header .avatar {
    padding: 16px;
}
.logo{
    width: 127px;

}
.avatar{
    width: 40px;
    border-radius: 50%;  
    padding: 7px;
      
}
.container{
    margin: auto;
    width: 450px;
}
.post{
    background-color: #ffffff;
    margin-bottom: 25px; 
    padding: 0;
}
.post-author{
    display: flex;
    align-items: center;
    padding: 7px;
}

.author-info h3 , .author-info h4{
    margin: 0;
    padding: 0;
    line-height: 1.3;
}

h3{
    font-size: 16px;
    font-weight: bold;
}
h4{
     font-size: 14px;
     font-weight: normal;
}
.post-image{
    width: 100%;
    cursor: pointer;
}
.post-action{
    padding: 10px 0 0px 3px;
}
.action-btn{
    background: none;
    border: none;
    cursor: pointer;
}

.action-btn:hover , .action-btn:active {
    opacity: 0.7;
}
.action-btn img{
    width: 28px;
    height: 30px;
}
.likes-counter{
    margin: 0px 10px;
}
.author-username{
    font-weight: bold;
}
.post-caption{
    padding: 0 0 16px 10px;
    margin-top: 10px;
}