*,
::after,
::before {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* html{scroll-behavior: smooth;} */

body {
    font-family: Arial, Helvetica, sans-serif;
    overflow: hidden;
}

nav {
    display: flex;
    justify-content: center;
    position: fixed;
    padding: 20px;
    min-width: 500px;
    right: 50%;
    top: 90vh;
    transform: translateX(50%);
    background-color: #f1f1ff;
    border-radius: 31px;
    cursor: pointer;
    color: rgb(46, 71, 146);
    -webkit-box-shadow: 4px 8px 19px -3px rgba(4, 4, 4, 0.27);
    box-shadow: 4px 8px 19px -3px rgba(4, 4, 4, 0.27);
}

nav span {
    margin: 0 10px;
    text-decoration: none;
    transition: 0.1s ease-in-out;
}

nav span:hover {
    text-decoration: underline overline wavy crimson;
}

section {
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

body>section.section-1 {
    background-color: crimson;
}

body>section.section-2 {
    background-color: royalblue;
}

body>section.section-3 {
    background-color: orangered;
}

body>section.section-4 {
    background-color: salmon;
}

body>section.section-5 {
    background-color: lightgreen;
}

body>section.section-6 {
    background-color: blueviolet;
}

section h2 {
    font-size: 50px;
    font-family: Merienda;
}


.container {
    margin: 10px;
    position: fixed;
    top: 2%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-width: 10%;
    height: 85vh;
}

button {
    padding: 15px 25px;
    border: unset;
    border-radius: 15px;
    color: #212121;
    z-index: 1;
    background: #e8e8e8;
    position: relative;
    font-weight: 1000;
    font-size: 16px;
    cursor: pointer;
    -webkit-box-shadow: 4px 8px 19px -3px rgba(0, 0, 0, 0.27);
    box-shadow: 4px 8px 19px -3px rgba(0, 0, 0, 0.27);
    -webkit-transition: all 250ms;
    transition: all 250ms;
    overflow: hidden;
}

.previous {
    visibility: hidden;
}

button::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 0;
    border-radius: 15px;
    background-color: #212121;
    z-index: -1;
    -webkit-box-shadow: 4px 8px 19px -3px rgba(0, 0, 0, 0.27);
    box-shadow: 4px 8px 19px -3px rgba(0, 0, 0, 0.27);
    -webkit-transition: all 250ms;
    transition: all 250ms
}

button:hover {
    color: #e8e8e8;
}

button:hover::before {
    width: 100%;
}