html{
    box-sizing: border-box;
    background: #9ad7f0;
    font-size: 20px;
    font-weight: 200; /*thick,thin,bold */ 
    font-family:'helvetica neue'; /*lspecifies the font*/
}
body{
    margin: 0;
}
*,*:before,*:after{
    box-sizing: inherit;
}
.panels{
    min-height: 100vh;
    overflow: hidden;
    display: flex;
    
   
}
.panel{
    background: #6B0F9C;
    box-shadow: inset 0 0 0 5px rgba(255,255,255,0.1);
    color: white;
    text-align: center;
    align-items: center;
    transition:
        font-size 0.7s cubic-bezier(0.61,-0.19, 0.7,-0.11),
        flex 0.7s cubic-bezier(0.61,-0.19, 0.7,-0.11),
        background 0.2s;
    font-size: 10px;
    background-size: cover;
    background-position: center;
    flex: 1; /* each size will be equal*/
    justify-content: center;
    flex-direction: column;
    display: flex;
}
.image1{
    background-image: url("image/cat.jpg");
}
.image2{
    background-image: url("image/michael-martinelli.jpg");
}
.image3{
    background-image: url("image/bird.jpg");
}
.image4{
    background-image: url("image/huper-by-joshua-earle.jpg");
}

/*flex childer*/
.panel > * {
    margin: 0;
    width: 100%;
    transition: transform 0.5s;
    /*border: 1px solid red;*/
    flex: 1 0 auto;
    display: flex;
    justify-content: center;
    align-items: center;
    align-items: center;
}

.panel > *:first-child { transform: translateY(-100%); }
.panel.open-active > *:first-child { transform: translateY(0); }
.panel > *:last-child { transform: translateY(100%); }
.panel.open-active > *:last-child { transform: translateY(0); }

.panel p {
    text-transform: uppercase;
    font-family: 'Amatic SC', cursive;
    text-shadow: 0 0 4px rgba(0, 0, 0, 0.72), 0 0 14px rgba(0, 0, 0, 0.45);
    font-size: 2em;
}
  
.panel p:nth-child(2) {
    font-size: 4em;
}

.panel.open {
    flex: 5;/*5 time big*/
    font-size: 10px;
}