html {
    box-sizing: border-box;
    background: #ffc600;
    font-family: 'helvetica neue';
    font-size: 20px;
    font-weight: 200;
}
  
body {
    margin: 0;
    cursor: default;
}

*, *: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;
    /* Safari transitionend event.propertyName === flex */
    /* Chrome + FF transitionend event.propertyName === flex-grow */
    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: 20px;
    background-size: cover;
    background-position: center;
    display: flex;
    flex: 1;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

.panel1 { background-image:url(img/image1.jpg); }
.panel2 { background-image:url(img/image2.jpg); }
.panel3 { background-image:url(img/image3.jpg); }
.panel4 { background-image:url(img/image4.jpg); }
.panel5 { background-image:url(img/image5.jpg); }

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

/* Toggle classes for text animation */
.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;
    font-size: 40px;
}