index.css

html, body {
    height: 100vh;
    width: 100vw;
}
body {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    box-sizing: border-box;
    font-family: 'Comfortaa', cursive;
    margin: 0;
}
.container {
    display: flex;
    flex-direction: column;
    max-width: min(100vw, 80rem);
    /* Hint */
}
.container > * {
    margin: 0.5rem;
}
.heading {
    font-size: 5rem;
    margin: 1.5rem;
    font-weight: 500;
}
@media screen and (max-width:540px) {
    .heading {
        font-size: 2.5rem;
    }
}
.description {
    font-style: oblique;
}
.search_wrapper {
    border: 0.125rem solid rgb(23, 23, 23);
    height: 3rem;
    padding: 0.25rem 0.75rem;
    box-sizing: border-box;
    border-radius: 0.5rem;
    display: flex;
    align-items: center;
}
.search_label{
    transition: linear 0.25s;
    transform: none;
    position: absolute;
    font-size: 1.25rem;
    transform-origin: left;
    background-color: white;
    padding: 0 0.5rem;
    z-index: -1;
    margin-left: 1.5rem;
}
.search_wrapper:focus-within {
    border-color: #303F9F;
}
.search_wrapper:focus-within > .search_label,
.search_input:valid + .search_label {
    transform: translateY(-1.5rem) scale(0.75);
    transition: linear 0.25s;
    z-index: 1;
    color: #303F9F;
}
.search_input,
.search_input:focus-visible {
    background-color: transparent;
    flex-grow: 1;
    border: none;
    font-family: 'Comfortaa', cursive;
    font-size: 1.5rem;
    padding: 0 0.5rem;
    outline: none;
    max-width: calc(100% - 2rem);
}
.search_button {
    width: max-content;
    display: flex;
    align-items: center;
    align-self: flex-end;
    color: white;
    background-color: #3F51B5;
    border-radius: 0.25rem;
    border: none;
    padding: 0.5rem 0.75rem;
}
.search_icon {
    width: 1.5rem;
    height: 1.5rem;
}