.sec1
{
  position: relative;
  width: 100%;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  background-attachment:fixed;
  background-repeat: no-repeat;
  background-size: cover;
}

.sec2
{
  position: relative;
  width: 100%;
  min-height: 40vh;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  background-attachment:fixed;
  background-repeat: no-repeat;
  background-size: cover;
}

.sec3
{
  position: relative;
  width: 100%;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  background-attachment:fixed;
  background-repeat: no-repeat;
  background-size: cover;
}

/*
    <div class="flip-img-container">
        <div class="flip-img">
            <a href="wbis.html">
                <div class="flip-box">
                    <div class="flip-box-inner">
                    <div class="flip-box-front">
                        <img src="images/water2.jpg" alt="WBIS">
                    </div>
                    
                    <div class="flip-box-back">
                        <h2>Water Billing Information System</h2>
                        <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Mollitia molestias temporibus quod itaque exercitationem quas expedita quo! Exercitationem optio veritatis excepturi dolores illum saepe, labore nobis alias, culpa dignissimos mollitia.</p>
                    </div> 
                </div>
            </a>
        </div>

        <div class="flip-img">
            <a href="mmr.html">
                <div class="flip-box">
                    <div class="flip-box-inner">
                    <div class="flip-box-front">
                        <img src="images/MMR.jpg" alt="MMR">
                    </div>
                    
                    <div class="flip-box-back">
                        <h2>Motor Meter Reading System</h2>
                        <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Mollitia molestias temporibus quod itaque exercitationem quas expedita quo! Exercitationem optio veritatis excepturi dolores illum saepe, labore nobis alias, culpa dignissimos mollitia.</p>
                    </div> 
                </div>
            </a>
        </div>

        <div class="flip-img">
            <a href="waqis.html">
                <div class="flip-box">
                    <div class="flip-box-inner">
                    <div class="flip-box-front">
                        <img src="images/waqis.jpg" alt="WAQIS">
                    </div>
                    
                    <div class="flip-box-back">
                        <h2>Water Quality Information System</h2>
                        <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Mollitia molestias temporibus quod itaque exercitationem quas expedita quo! Exercitationem optio veritatis excepturi dolores illum saepe, labore nobis alias, culpa dignissimos mollitia.</p>
                    </div> 
                </div>
            </a>
        </div>
    </div>

*/