style.css

/* Colour variables  */

:root {
    --purple: rgba(54, 50, 93, 1);
    --orchid: rgba(179, 106, 245, 1);
    --iris: rgba(122, 83, 246, 1);
    --dark-purple: rgba(42, 39, 78, 1);
    --darkest-purple: rgba(8, 12, 40, 1);
    --transparent: rgba(255, 255, 255, 0);
    --white: rgba(222, 226, 230, 1);
}

/* Scrollbar  */

.c-scrollbar_thumb {
    background-color: var(--white);
    z-index: 20;
}

/* Document and sections */

body {
    background: linear-gradient(175deg, var(--dark-purple) 0%, var(--darkest-purple) 100%);
    font-family: "Exo";
    font-weight: 200;
}

.main-content {
    margin-top: 120px;
    padding: 30px;
}

header {
    background-color: var(--purple);
    z-index: 20;
    position: fixed;
    top: 0;
    width: 100%;
}

.main-content,
footer {
    max-width: 1150px !important;
}

footer {
    padding: 40px 0 30px 0;
}

section {
    position: relative;
    margin-bottom: 30px;
}

.disclaimer {
    font-size: 13px;
    line-height: 27px;
    margin-top: 80px !important;
}

/* Locomotive elements overlap, preventing image carousel navigation from 
being clicked. A fix for this is to increase the z-index on each section. */

#mercury {
    z-index: 9;
}

#venus {
    z-index: 8;
}

#earth {
    z-index: 7;
}

#mars {
    z-index: 6;
}

#jupiter {
    z-index: 5;
}

#saturn {
    z-index: 4;
}

#uranus {
    z-index: 3;
}

#neptune {
    z-index: 2;
}

/* Images */

.logo {
    height: 43px;
}

.down-arrow {
    position: relative;
    left: 0;
    bottom: 0;
    width: 21px;
    animation: point-down 3s ease-in-out infinite;
}

@keyframes point-down {
    0%,
    100% {
        bottom: 0;
    }

    50% {
        bottom: 30px;
    }
}

/* Text */

h1 {
    display: none;
    font-size: 0px;
}

h2 {
    margin-bottom: 30px;
    font-weight: 600;
    font-size: 50px;
}

.hero h2 {
    margin: 150px 0 100px 0;
    font-weight: 300;
    font-size: 76px;
    line-height: 107px;
}

p {
    line-height: 30px;
    font-weight: 200;
}

p:last-of-type {
    margin: 0px;
}

.accent {
    font-size: 23px;
    font-weight: 600;
    line-height: 35px;
}

.bold {
    font-weight: 600;
}

.offcanvas-title {
    font-size: 20px;
    font-weight: 600;
    line-height: 32px;
}

/* Buttons */

.btn-gradient,
sl-button::part(base),
sl-button.gradient-outline::part(base) {
    border-radius: 12px;
    padding: 12px 30px 12px 30px;
    font-weight: 400;
    min-width: 145.53px;
    border: 2px solid transparent;
    position: relative;
    z-index: 1;
}

.btn-gradient,
sl-button::part(base),
sl-button.gradient-outline::part(base):before {
    background: linear-gradient(var(--transparent), var(--transparent)) padding-box, linear-gradient(158deg, var(--orchid) 0%, var(--iris) 100%) border-box;
}

.btn-gradient:before,
sl-button.gradient-outline::part(base),
sl-button::part(base):before  {
    background: linear-gradient(var(--purple), var(--purple)) padding-box, linear-gradient(158deg, var(--orchid) 0%, var(--iris) 100%) border-box;
}

.btn-gradient:before,
sl-button::part(base):before,
sl-button.gradient-outline::part(base):before {
    position: absolute;
    content: "";
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    z-index: -1;
    opacity: 0;
    border-radius: 10px;
    transition: opacity 0.15s linear;
}

.btn-gradient:hover::before,
sl-button::part(base):hover::before,
sl-button.gradient-outline::part(base):hover::before {
    opacity: 1;
}

sl-button::part(label) {
    line-height: 1.5;
    font-family: "Exo";
    font-size: 16px;
}

/* Hamburger menu button */

.navbar-toggler {
    border: none;
    color: var(--transparent);
}

/* Planet picker dropdown */

.planet-picker-btn {
    text-align: left;
    width: 240px;
    display: flex;
    border-radius: 12px;
    padding: 12px 22px 12px 22px;
    font-weight: 400;
    background: linear-gradient(var(--purple), var(--purple)) padding-box, linear-gradient(158deg, var(--orchid) 0%, var(--iris) 100%) border-box;
    border: 2px solid transparent;
}

.btn-check:checked+.btn,
.btn.active,
.btn.show,
.btn:first-child:active,
:not(.btn-check)+.btn:active {
    background: linear-gradient(var(--purple), var(--purple)) padding-box, linear-gradient(158deg, var(--orchid) 0%, var(--iris) 100%) border-box;
    border: 2px solid transparent;
}

.dropdown-item.active, 
.dropdown-item:active {
    background-color: unset;
}

.planet-picker-btn::after {
    margin-top: auto;
    margin-bottom: auto;
    margin-left: auto;
}

.planet-picker-dropdown {
    padding: 15px 0 15px 0;
    width: 240px;
    border-radius: 12px;
    border: 0px;
    margin-top: 5px !important;
}

.dropdown-item:hover {
    border-radius: 0px;
}

.planet-picker-dropdown li a {
    padding: 12px 22px 12px 22px;
    font-weight: 400;
}

.planet-picker {
    display: flex;
    justify-content: center;
    font-weight: 400;
}

/* Mobile menu elements */

.planet-picker-mobile a {
    text-decoration: none;
    color: var(--white);
}

.planet-picker-mobile a:hover {
    text-decoration: underline;
    text-underline-offset: 2px;
    text-decoration-thickness: 1px;
}

.planet-picker-mobile {
    display: none;
    list-style-type: none !important;
    padding-left: 0px;
    margin-bottom: 30px;
    font-weight: 400;
}

.planet-picker-mobile li {
    padding: 18px 0 18px 0;
}

[data-bs-theme=dark] .navbar-toggler-icon {
    --bs-navbar-toggler-icon-bg: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba%28222, 226, 230, 1%29' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e")
}

.offcanvas {
    width: 300px !important;
    border-width: 0px !important;
}

.navbar-toggler {
    padding-right: 0px;
}

.btn-close {
    --bs-btn-close-opacity: 1 !important;
    opacity: 1 !important;
    filter: unset !important;
    --bs-btn-close-bg: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='rgba%28222, 226, 230, 1%29'%3e%3cpath d='M.293.293a1 1 0 0 1 1.414 0L8 6.586 14.293.293a1 1 0 1 1 1.414 1.414L9.414 8l6.293 6.293a1 1 0 0 1-1.414 1.414L8 9.414l-6.293 6.293a1 1 0 0 1-1.414-1.414L6.586 8 .293 1.707a1 1 0 0 1 0-1.414z'/%3e%3c/svg%3e")
}

.btn-close:focus {
    box-shadow: none;
}

/* Lists */

dl {
    margin-bottom: 0px;
}

dt {
    font-weight: 200;
    margin-bottom: 5px;
}

dt:nth-of-type(even) {
    margin-top: 25px;
}

dd {
    font-size: 23px;
    font-weight: 600;
    margin-bottom: 0px;
}

/* Splide carousel */

.splide__slide img {
    width: 100%;
    height: 550px;
    object-fit: cover;
    border-radius: 25px;
}

.splide__pagination {
    display: none;
}

.splide__arrows {
    position: relative;
    font-size: 35px;
    top: 45px;
}

.splide__arrow {
    background: none;
    color: var(--white);
    opacity: 1;
}

.splide__arrow--prev {
    left: 33%;
}

.splide__arrow--next {
    right: 33%
}

.splide__arrow:hover:not(:disabled) {
    opacity: 1;
    color: var(--orchid);
}

/* Bootstrap gutter override */

.g-5 {
    --bs-gutter-y: 4rem;
    --bs-gutter-x: 4rem;
}

/* Locomotive fix flickering of elements when scrolling (KarsusITA 2022) */

.has-scroll-smooth {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
}

/* Quiz elements */

#planet-quiz {
    padding-top: 60px;
    margin-top: -60px;
}

.quiz-radio {
    display: block;
    text-align: left;
    margin-bottom: 20px;
    border-radius: 12px;
    padding: 14px 32px 14px 32px;
    font-weight: 400;
    color: var(--white);
    background: none;
    border: 2px solid var(--white);
    transition: .2s ease-in-out 0s;
}

.btn-check+.btn:hover {
    border: 2px solid var(--white);
    background-color: var(--white);
    color: var(--purple);
}

.btn-check:checked+.btn {
    border: 2px solid var(--white);
    color: var(--purple);
    background: var(--white);
}

.quiz-letter {
    margin-right: 30px;
}

.background-panel {
    background-color: var(--purple);
    border-radius: 25px;
    z-index: 1;
}

sl-progress-bar {
    --track-color: #dee2e691;
    margin-top: 5px;
    --height: 13px;
}

sl-progress-bar::part(indicator) {
    background: linear-gradient(158deg, var(--orchid) 0%, var(--iris) 100%);
}

.quiz-progress dt,
.quiz-progress dd {
    font-size: 16px;
    font-weight: 200;
}

.tab,
#quiz-question-area {
    display: none;
}

.tab:first-of-type {
    display: block;
}

.quiz-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-top-right-radius: 25px;
    border-bottom-right-radius: 25px;
}

.panel-content {
    padding: 68px;
}

/* Quiz dialog box */

sl-dialog::part(overlay) {
    background-color: #000000d9;
}

sl-dialog::part(panel) {
    border-radius: 18px;
    background-color: var(--purple);
    padding: 15px;
    width: 516px;
}

sl-dialog::part(header) {
    font-size: 23px;
    font-weight: 600;
    line-height: 35px;
    color: var(--white);
}

sl-dialog::part(body) {
    font-size: 16px;
    color: var(--white);
}

sl-dialog::part(close-button__base) {
    color: var(--white);
    transition: .2s ease-in-out 0s;
}

sl-dialog::part(close-button__base):hover {
    color: var(--white);
    transform: scale(1.4);
}

/* Social media icons */

.social-icons .fa-circle {
    color: var(--white);
}

.social-icons .fa-brands {
    color: var(--darkest-purple) !important;
}

.social-icons {
    font-size: 23px !important;
    transition: .2s ease-in-out 0s;
    margin-left: 3px;
    margin-right: 3px;
}

.social-icons:hover {
    transform: scale(1.15);
}

.social-icons .fa-instagram {
    font-size: 26px;
}

sl-tooltip::part(body) {
    font-family: "Exo" !important;
    font-weight: 200;
    font-size: 13px;
}

/* For screen reader only elements (Berryhill 2021) */

.screen-reader-only {
    border: 0;
    clip-path: inset(0px 0px 0px 0px);
    height: 1px;
    margin: -1px;
    overflow: hidden;
    padding: 0;
    position: absolute;
    width: 1px;
}

/* Hero section */

.hero {
    left: 0;
    width: 100%;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0px !important;
}

.hero::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url("images/stars.jpg"); /* Figure 1. Black and white starry night */
    background-attachment: fixed;
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
}

.hero-content {
    position: relative;
    color: #FFFFFF;
    text-align: center;
    width: 58%;
}

/* Bootstrap large breakpoint */

@media only screen and (max-width: 991px) {
    .content-col {
        order: 2;
    }

    .image-col {
        order: 1;
    }

    .quiz-image,
    .planet-picker span { 
        display: none;
    }

    .dropdown {
        margin-left: 0px;
    }

    .col-lg-6 {
        margin-top: 0px;
    }

    section:not(.hero, #planet-quiz, #neptune) {
        margin-bottom: 100px;
    }

    section:not(.hero, #planet-quiz) {
        padding-left: 68px;
        padding-right: 68px;
    }

    .hero h2 {
        font-size: 66px;
        line-height: 97px;
    }

    .hero-content {
        width: 70%;
    }
}

/* Bootstrap medium breakpoint */

@media only screen and (max-width: 767px) {
    .navbar-collapse .text-end {
        text-align: center !important;
    }

    .planet-picker-mobile {
        display: block;
    }

    .planet-picker {
        display: none;
    }

    .logo {
        height: 38px;
    }

    .hero h2 {
        font-size: 56px;
        line-height: 87px;
    }

    .offcanvas-body {
        margin-left: unset !important;
    }

    .offcanvas {
        padding-left: 25px;
        padding-top: 15px;
    }

    .offcanvas .text-end {
        text-align: left !important;
    }

    .btn-gradient:before {
        background: linear-gradient(var(--bs-offcanvas-bg), var(--bs-offcanvas-bg)) padding-box, linear-gradient(158deg, var(--orchid) 0%, var(--iris) 100%) border-box;
    }
}

@media only screen and (max-width: 614px) {
    .panel-content {
        padding: 45px;
    }

    section:not(.hero, #planet-quiz) {
        padding-left: 45px;
        padding-right: 45px;
    }

    .accent {
        font-size: 16px;
        line-height: 30px;
    }

    .hero h2 {
        font-size: 46px;
        line-height: 77px;
        margin: 120px 0 70px 0;
    }
}

/* Bootstrap small breakpoint */

@media only screen and (max-width: 575px) {
    .btn-gradient:not(.offcanvas .btn-gradient) {
        width: 100%;
    }

    #nextButton {
        margin-top: 20px;
    }

    .splide__arrow--prev {
        left: 25%;
    }

    .splide__arrow--next {
        right: 25%
    }

    .splide__slide img {
        height: 400px;
    }

    #next-button {
        margin-top: 30px;
    }
}

@media only screen and (max-width: 414px) {
    dd {
        font-size: 16px;
    }

    .main-content {
        padding: 30px;
    }

    h2 {
        font-size: 32px;
    }

    .hero h2 {
        font-size: 40px;
        line-height: 54px;
    }
    
    section:not(.hero, #planet-quiz) {
        padding-left: 0px;
        padding-right: 0px;
    }
}