/* Adapted from https://codyhouse.co/gem/vertical-timeline/ with significant
 * modifications.
 * */

:root {
    --side-spacing: 0;
    --background-color: rgb(232, 239, 245);
    --accent: hsl(205, 26%, 84%);

    --timeline-line-color: hsl(205, 38%, 89%);
    --timeline-line-width: 4px;
    --timeline-line-half-width: calc(var(--timeline-line-width) / 2);

    --content-background-color: white;
    --content-padding: 1.25rem;

    --icon-width: 60px;
    --icon-half-width: calc(var(--icon-width) / 2);
    --icon-border-width: 4px;
    --icon-border-color: white;
    --icon-color: white;
    --icon-image-width: 40px;
    --icon-size: 1.5rem;
    --icon-side-spacing: 1.5rem;

    --date-color: hsl(0, 0%, 48%);
    --arrow-size: 7px;
}

[data-theme="dark"] {
    --background-color: #2C2F33;
    --content-background-color: #23272A;
    --accent: hsl(0, 0%, 34%);
    --timeline-line-color: var(--accent);

    --icon-border-color: hsl(0, 0%, 50%);
}

@media (max-width: 1023px) {
    :root {
        --side-spacing: 1.25rem;
        --icon-side-spacing: var(--side-spacing);
        --icon-width: 40px;
        --icon-image-width: 30px;
        --icon-size: 1.1rem;
    }
}

/* Use a tighter margin and smaller icon dimensions on the most narrow screens.
 * */
@media (max-width: 600px) {
    :root {
        --side-spacing: .75rem;
        --icon-side-spacing: .5rem;
        --timeline-line-width: 3px;
        --icon-width: 30px;
        --icon-border-width: 3px;
        --icon-image-width: 24px;
        --icon-size: .9rem;
    }
}

/* Containers */
.timeline {
    overflow: hidden;
    padding: 3rem 0;
    background-color: var(--background-color);
}

.timeline .container {
    position: relative;
    padding: 1rem var(--side-spacing);
}

/* The line that goes through all the icons */
.timeline .container::before {
    content: '';
    position: absolute;

    height: 100%;
    width: var(--timeline-line-width);
    background-color: var(--timeline-line-color);
    z-index: 1;
}

@media (min-width: 1023px) {
    .timeline .container::before {
        left: calc(50% - var(--timeline-line-half-width));
    }
}

@media (max-width: 1023px) {
    .timeline .container::before {
        margin-left: calc(var(--icon-half-width) - var(--timeline-line-half-width));
    }
}

/* Each timeline item */
.timeline-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: 2.5rem;
}

/* Arrow indicator on the top left/right of each content box */
.timeline-content::before {
    content: '';
    position: absolute;
    border: solid var(--arrow-size) transparent;
    border-right-color: var(--accent);
    height: 0;
}

@media (max-width: 1023px) {
    .timeline-content::before {
        margin-left: calc(0px - var(--content-padding) - 14px);
        margin-top: calc(0px - var(--arrow-size) / 2);
    }
}

@media (max-width: 600px) {
    .timeline-content::before {
        margin-top: calc(0px - var(--icon-half-width) + var(--arrow-size));
    }
}

@media (min-width: 1023px) {
    .timeline-content::before {
        right: 100%;
        margin-top: var(--arrow-size);
    }
    .timeline-item:nth-child(odd) .timeline-content::before {
        border-left-color: var(--accent);
        border-right-color: transparent;
        left: 100%;
        right: unset;
    }
}

/* Visual container of the timeline item */
.timeline-content.box {
    padding: var(--content-padding);
    box-shadow: var(--accent) 0px 3px 0px 0px;
    background-color: var(--content-background-color);
    flex-grow: 1;
}

@media (min-width: 1023px) {
    .timeline-item:nth-child(odd) {
        flex-direction: row-reverse;
    }
    /* On desktop, the content boxes are anchored with respect to the vertical
     * center of the screen, set using `left`/`right` properties depending on
     * even and odd children of timeline items.
     * */
    .timeline-content.box  {
        width: 45%;
        flex-grow: 0;

        position: relative;

        --content-position: calc(50% + var(--icon-border-width) + var(--icon-half-width));

        left: var(--content-position);
        margin-left: var(--icon-side-spacing);
    }
    .timeline-item:nth-child(odd) .timeline-content.box {
        left: unset;
        right: var(--content-position);
        margin-right: var(--icon-side-spacing);
    }
}

@media (max-width: 1023px) {
    .timeline-content.box {
        margin-left: calc(var(--icon-side-spacing) + var(--arrow-size));
    }
}

/* The icon and date components are grouped together in a flexbox to ensure
 * there are center-aligned vertically on both desktop and mobile screens. This
 * also makes it easy to both have dates' horizontal position follow that of
 * the icon, and reverse their ordering for alternate timeline items on
 * desktop.
 * */
.timeline-icon-date {
    z-index: 4;
    display: flex;
    align-items: baseline;
}

@media (min-width: 1023px) {
    .timeline-icon-date {
        order: 1;

        /* Arbitrary container width to prevent wrapping of the date text */
        width: 50%;
        align-items: center;
        gap: var(--icon-side-spacing);

        position: absolute;
        left: calc(50% - var(--icon-half-width));
    }

    .timeline-item:nth-child(even) .timeline-icon-date {
        flex-direction: row-reverse;
        left: unset;
        right: calc(50% - var(--icon-half-width));
    }
}

/* Icon */
.timeline-icon {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-shrink: 0;

    border-radius: 50%;
    height: var(--icon-width);
    width: var(--icon-width);
    /* The border does not actually use the border property because this border
     * needs to cover the bottom box-shadow, which is easier if the border is
     * implemented as a box-shadow.
     * */
    box-shadow: 0 0 0 var(--icon-border-width) var(--icon-border-color),
                inset 0 2px 0 rgba(0,0,0,.08),
                0 3px 0 4px rgba(0,0,0,.05);
    margin-top: var(--icon-border-width);

    /* Font Awesome icon size and color */
    color: var(--icon-color);
    font-size: var(--icon-size);
}

/* Icons that use a custom image */
.timeline-icon img {
    width: var(--icon-image-width);
    height: var(--icon-image-width);
}

/* Icons that use the pydis logo */
.timeline-icon img.pydis {
    /* Visually centering the pydis logo requires a margin adjustment here
     * due to the right and bottom box shadow on the logo which is not very
     * visible on the page.
     *
     * XXX: Hardcoded; Unresponsive to actual image dimensions.
     * */
    margin-top: 1px;
    margin-left: 1px;
}

.timeline-date {
    font-size: .9rem;
    color: var(--date-color);
}

@media (min-width: 1023px) {
    .timeline-item:nth-child(even) .timeline-date {
        left: auto;
        right: 50%;
        text-align: right;
    }
}

@media (max-width: 1023px) {
    .timeline-date {
        position: absolute;
        /* On mobile, place the date at the top of the text box left-aligned
         * with the other text in the box. When margin-left is zero, the date
         * is left-aligned to the left of the icon (right of box-shadow).
         * */
        margin-left: calc(var(--icon-width) + var(--icon-side-spacing)
                        + var(--arrow-size) + var(--content-padding));
        margin-top: .75rem;
    }

    .timeline-content.content h3 {
        /* Make space for the date text */
        margin-top: 1.25rem;
    }
}

/* Icon background colors */
.pastel-red {
    background-color: #ff7878 !important;
}
[data-theme="dark"] .pastel-red {
    background-color: #a44848 !important;
}
.pastel-orange {
    background-color: #ffbf76 !important;
}
[data-theme="dark"] .pastel-orange {
    background-color: #967147 !important;
}
.pastel-green {
    background-color: #8bd6a7 !important;
}
[data-theme="dark"] .pastel-green {
    background-color: #649f7a !important;
}
.pastel-blue {
    background-color: #8edbec !important;
}
[data-theme="dark"] .pastel-blue {
    background-color: #3d7986 !important;
}
.pastel-purple {
    background-color: #cbb1ff !important;
}
[data-theme="dark"] .pastel-purple {
    background-color: #8775ad !important;
}
.pastel-pink {
    background-color: #f6acff !important;
}
[data-theme="dark"] .pastel-pink {
    background-color: #79507e !important;
}
.pastel-lime {
    background-color: #b6df3a !important;
}
[data-theme="dark"] .pastel-lime {
    background-color: #7c9a21 !important;
}
.pastel-dark-blue {
    /* Works well for both themes */
    background-color: #576297 !important;
}

img, video, svg {
    max-width: 100%
}

/* Bounce-in and bounce-out animations, desktop-only */
@media (min-width: 1023px) {
    .timeline-icon--hidden, .timeline-content--hidden, .timeline-date--hidden {
        visibility: hidden;
    }
    .timeline-icon--bounce-in {
        animation: icon-bounce 0.6s;
    }
    .timeline-content--bounce-in,
    .timeline-date--bounce-in {
        animation: item-bounce-left 0.6s;
    }
    .timeline-item:nth-child(even) .timeline-content--bounce-in,
    .timeline-item:nth-child(even) .timeline-date--bounce-in {
        animation-name: item-bounce-right;
    }
    .timeline-icon--bounce-out {
        animation: icon-bounce-out 0.6s;
    }
    .timeline-content--bounce-out,
    .timeline-date--bounce-out {
        animation: item-bounce-out 0.6s;
    }
}

@keyframes icon-bounce {
    0% {
        opacity: 0;
        transform: scale(0.5);
    }
    60% {
        opacity: 1;
        transform: scale(1.2);
    }
    100% {
        transform: scale(1);
    }
}

@keyframes item-bounce-left {
    0% {
        opacity: 0;
        transform: translateX(-100px)
    }
    60% {
        opacity: 1;
        transform: translateX(20px)
    }
    100% {
        transform: translateX(0)
    }
}

@keyframes item-bounce-right {
    0% {
        opacity: 0;
        transform: translateX(100px)
    }
    60% {
        opacity: 1;
        transform: translateX(-20px)
    }
    100% {
        transform: translateX(0)
    }
}

@keyframes icon-bounce-out {
    0% {
        opacity: 1;
        transform: scale(1);
    }

    60% {
        transform: scale(1.2);
    }

    100% {
        opacity: 0;
        transform: scale(0.5);
    }
}

@keyframes item-bounce-out {
    0% {
        opacity: 1;
        transform: translateX(0);
    }
    60% {
        transform: translateX(20px);
    }
    100% {
        opacity: 0;
        transform: translateX(-100px);
    }
}