index.css

* {
    box-sizing: border-box;
}
/* Style the body */
body {
    font-family: Arial, Helvetica, sans-serif;
    margin: 0;
}

/* Header/logo Title */
.header {
    padding: 1px;
    text-align: center;
    background: #1abc9c;
    color: white;
}

/* Increase the font size of the heading */
.header h1 {
    font-size: 30px;
}

/* Style the top navigation bar */
.navbar {
    overflow: hidden;
    background-color: #333;
}

/* Style the navigation bar links */
.navbar a {
    float: left;
    display: block;
    color: white;
    text-align: center;
    padding: 14px 20px;
    text-decoration: none;
}

/* Right-aligned link */


/* Change color on hover */
.navbar a:hover {
    background-color: #ddd;
    color: magenta;
}
.wrapper div{
   display: flex;
   /*flex-direction: row;*/
    border:1px #ccc solid;
}
.wrapper{
    display:flex;
    flex-wrap: wrap;
    /*columns: auto auto;*/
    background-color:#f4f4f4;
    justify-content:space-between;
    /*padding-right: 0px;*/
   
}
.leftWala {
    
    /*float: left;*/
    cursor: pointer;
    background-color:pink;
    width:650px;
}
.leftWala p{
    padding-left: 40px;
    padding-top: 80px;
    font-family:sans-serif;
    /*breakpoint-md:768px;*/
    /*text-decoration-style:dotted;*/
}

.right-wala {
    float: right;
    background-color:#343a40;
    /*width: 600px;*/
    background-repeat: no-repeat;
   
}
.div-img{
    margin-left: 200px;
}
.quat u h3{
    background-color:maroon; 
    color:white;
}
.quat h2:hover{
    background:maroon;
    color: white;
}
.quat h3{
    background:#779900;
    color:black;

}
/*///////image container//////////*/
.mar-img div{
   display: flex;
   flex-direction: row;
    border:1px #ccc solid;
}
.mar-img{
     display:flex;
     flex-wrap: wrap;
     flex-direction: row;
    /*columns: auto auto;*/
     background-color: #f4f4f4;
     justify-content:space-between;
}
/* Create two unequal columns that sits next to each other */
/* Sidebar/left column */
.side {
    -ms-flex: 30%; 
    flex: 30%;
    background-color:#f4f4f4;
    padding: 20px;
}

/* Main column */
.main {   
    -ms-flex: 70%;
    flex: 70%;
    background-color:transparent;
    padding: 20px;
    background-repeat: no-repeat;
}
/* Fake image, just for this example */
/*three flex box***************/
.container-1 div{
    display: flex;
    flex-direction: row;
    border:1px #ccc solid;

  }
.container-1{
    display: flex;
    flex-wrap: wrap;
    /*flex-direction: row;*/
    background-color: #f4f4f4;
     justify-content: space-between;
}
/* Footer */
#main-footer{
    padding: 5px;
    text-align: center;
    background: black;
    color: white;
}
.pro h4{
    font-family: Arial, Helvetica, sans-serif;
    color: black;
}
/* Responsive layout - when the screen is less than 700px wide, make the two columns stack on top of each other instead of next to each other */
@media screen and (max-width: 700px) {
    .row {   
        flex-direction: column;
    }
}

/* Responsive layout - when the screen is less than 400px wide, make the navigation links stack on top of each other instead of next to each other */
@media screen and (max-width: 400px) {
    .navbar a {
        float: none;
        width: 100%;
    }
}
/*@media screen and(max-width: 400px){
    .wrapper div{
        float:none;
        width: 100%;
    }
}Not working*/
/*@media screen and(max-width: 400px){
    .container div{
        float:none;
        width: 100%;
    }
}*/
/*@media screen and(max-width: 400px){
    .container-1 div{
        float:none;
        width: 100%;
    }
}*/