/* ═══════════════════════════════════════════════════════════════
   robotics-timeline.css  (v3)
   Uses site root colour vars + Circular Spotify font.
   Only rt-* classes — no overlap with existing stylesheets.
═══════════════════════════════════════════════════════════════ */

/* ── Page wrapper ───────────────────────────────────────────── */
.rt-page {
    max-width: 1100px;
    margin: 0 auto;
    padding: 32px 32px 32px;
    box-sizing: border-box;
    font-family: 'Circular Spotify', sans-serif;
    color: var(--color-text-1);
}

.rt-header {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 32px;
}

/* ── Header ─────────────────────────────────────────────────── */
.rt-eyebrow {
    font-family: 'Circular Spotify', sans-serif;
    font-size: 0.72rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--color-primary-a30);
    margin: 0 0 12px;
}

.rt-title {
    font-family: 'Circular Spotify', sans-serif;
    font-size: clamp(2.4rem, 6vw, 4rem);
    font-weight: 800;
    line-height: 1.05;
    margin: 0 0 18px;
    letter-spacing: -0.03em;
    color: var(--color-text-1);
}

.rt-subtitle {
    font-family: 'Circular Spotify', sans-serif;
    font-size: 1rem;
    color: var(--color-text-2);
    max-width: 460px;
    line-height: 1.6;
}

/* ── Timeline scaffold ──────────────────────────────────────── */
.rt-timeline-wrapper {
    position: relative;
}

.rt-line {
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    transform: translateX(-50%);
    background: var(--color-primary-a20);
    pointer-events: none;
}

/* ════════════════════════════════════════════
   NODE — full unit (row + accordion panel)
════════════════════════════════════════════ */
.rt-node {
    position: relative;
    margin-bottom: 0;
}

/* ── Summary row (always visible) ───────── */
.rt-node-row {
    display: grid;
    grid-template-columns: 1fr 56px 1fr;
    align-items: center;
    padding: 18px 0;
    position: relative;
    z-index: 2;
}

.rt-node-left {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    padding-right: 28px;
    gap: 3px;
}
.rt-node-right {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    padding-left: 28px;
    gap: 3px;
}

.rt-node[data-side="right"] .rt-node-right { visibility: hidden; }
.rt-node[data-side="left"]  .rt-node-left  { visibility: hidden; }

.rt-date-label {
    font-family: 'Circular Spotify', sans-serif;
    font-size: 0.72rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-primary-a30);
    line-height: 1;
    pointer-events: none;
}

.rt-node-title-preview {
    font-family: 'Circular Spotify', sans-serif;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--color-text-2);
    line-height: 1.2;
    transition: color 0.18s;
    pointer-events: none;
}

.rt-node.rt-open   .rt-node-title-preview,
.rt-node-row:hover .rt-node-title-preview {
    color: var(--color-text-1);
}

/* ── Dot button ── THE interactive trigger ─ */
.rt-dot-btn {
    background: none;
    border: none;
    padding: 0;
    margin: 0 auto;
    font: inherit;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    position: relative;
    z-index: 3;
    outline: none;
    -webkit-tap-highlight-color: transparent;
    background-color: var(--color-primary-a0);
}

/* Ring */
.rt-dot-btn::before {
    content: '';
    position: absolute;
    inset: 6px;
    border-radius: 50%;
    border: 2px solid var(--color-primary-a30);
    transition: border-color 0.2s, transform 0.25s cubic-bezier(.4,0,.2,1),
                box-shadow 0.2s;
}

/* Fill */
.rt-dot-btn::after {
    content: '';
    position: absolute;
    inset: 6px;
    border-radius: 50%;
    background: var(--color-selected-1);
    opacity: 0;
    transform: scale(0.5);
    transition: opacity 0.2s, transform 0.25s cubic-bezier(.4,0,.2,1);
}

/* Plus icon bars */
.rt-dot-icon {
    position: relative;
    width: 12px;
    height: 12px;
    z-index: 1;
    flex-shrink: 0;
}
.rt-dot-icon::before,
.rt-dot-icon::after {
    content: '';
    position: absolute;
    background: var(--color-primary-a30);
    border-radius: 2px;
    transition: transform 0.3s cubic-bezier(.4,0,.2,1), background 0.2s;
}
.rt-dot-icon::before { width: 12px; height: 2px; top: 5px; left: 0; }
.rt-dot-icon::after  { width: 2px; height: 12px; top: 0;  left: 5px; }

/* Hover */
.rt-dot-btn:hover::before {
    border-color: var(--color-selected-2);
    transform: scale(1.12);
}
.rt-dot-btn:hover::after {
    opacity: 0.25;
    transform: scale(1.12);
}
.rt-dot-btn:hover .rt-dot-icon::before,
.rt-dot-btn:hover .rt-dot-icon::after {
    background: var(--color-selected-3);
}

/* Focus ring */
.rt-dot-btn:focus-visible::before {
    border-color: var(--color-selected-3);
    box-shadow: 0 0 0 3px var(--color-selected-glow-1);
}

/* Open state */
.rt-node.rt-open .rt-dot-btn::before {
    border-color: var(--color-selected-3);
    transform: scale(1.12);
    box-shadow: 0 0 0 3px var(--color-selected-glow-1);
}
.rt-node.rt-open .rt-dot-btn::after {
    opacity: 0.3;
    transform: scale(1.12);
}
.rt-node.rt-open .rt-dot-icon::before,
.rt-node.rt-open .rt-dot-icon::after {
    background: var(--color-selected-3);
}
.rt-node.rt-open .rt-dot-icon::before { transform: rotate(45deg); }
.rt-node.rt-open .rt-dot-icon::after  { transform: rotate(45deg); }

/* ════════════════════════════════════════════
   ACCORDION PANEL
════════════════════════════════════════════ */
.rt-panel-wrap {
    display: grid;
    grid-template-rows: 0fr;
    transition: grid-template-rows 0.4s cubic-bezier(.4,0,.2,1);
    position: relative;
    z-index: 1;
}
.rt-node.rt-open .rt-panel-wrap {
    grid-template-rows: 1fr;
}

.rt-panel-overflow {
    overflow: hidden;
    opacity: 0;
    transition: opacity 0.25s 0.08s;
}
.rt-node.rt-open .rt-panel-overflow {
    opacity: 1;
}

.rt-panel {
    padding: 0 0 36px;
}

.rt-panel-inner {
    border: 1.5px solid var(--color-primary-a20);
    border-radius: 16px;
    overflow: hidden;
    background: var(--color-primary-a10);
}

/* Two-column layout: image | text */
.rt-panel-body {
    display: grid;
    grid-template-columns: 1fr 1fr;
}
.rt-panel-body.rt-no-image {
    grid-template-columns: 1fr;
}

/* Image cell */
.rt-panel-image-wrap {
    overflow: hidden;
    min-height: 260px;
    position: relative;
    background: var(--color-primary-a20);
}
.rt-panel-image-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.rt-panel-image-wrap video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* Placeholder */
.rt-panel-image-wrap.rt-placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary-a20);
}
.rt-panel-image-wrap.rt-placeholder::after {
    content: '[ image ]';
    font-family: 'Circular Spotify', sans-serif;
    font-size: 0.7rem;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--color-primary-a30);
}

/* Text cell */
.rt-panel-text {
    padding: 32px 36px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 10px;
}

.rt-panel-date {
    font-family: 'Circular Spotify', sans-serif;
    font-size: 0.68rem;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--color-primary-a30);
    margin: 0;
}

.rt-panel-title {
    font-family: 'Circular Spotify', sans-serif;
    font-size: 1.4rem;
    font-weight: 700;
    line-height: 1.15;
    margin: 0;
    color: var(--color-text-1);
}

.rt-panel-desc {
    font-family: 'Circular Spotify', sans-serif;
    font-size: 0.88rem;
    line-height: 1.7;
    color: var(--color-text-2);
    margin: 2px 0 0;
}

/* Tag chips */
.rt-panel-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 8px;
}
.rt-tag {
    font-family: 'Circular Spotify', sans-serif;
    font-size: 0.66rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    border: 1px solid var(--color-primary-a20);
    border-radius: 999px;
    padding: 3px 10px;
    color: var(--color-primary-a30);
    background: var(--color-primary-a20);
    transition: border-color 0.15s, color 0.15s;
}
.rt-tag:hover {
    border-color: var(--color-selected-1);
    color: var(--color-selected-3);
}

/* ── End cap ─────────────────────────────────────────────────── */
.rt-end-cap {
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 16px;
    z-index: 2;
    transform: translateY(0px);
}

.rt-end-cap span {
    font-family: 'Circular Spotify', sans-serif;
    font-size: 0.7rem;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--color-text-1);
    border: 1.5px solid var(--color-selected-2);
    border-radius: 999px;
    padding: 5px 18px;
    background-color: var(--color-selected-1);
}

/* ── Mobile ──────────────────────────────────────────────────── */
@media (max-width: 640px) {
    .rt-page { padding: 16px 16px 100px; }

    .rt-line { left: 22px; }

    .rt-node-row {
        grid-template-columns: 44px 1fr;
        padding: 14px 0;
    }

    .rt-node-left { display: none; }
    .rt-node[data-side="right"] .rt-node-right,
    .rt-node[data-side="left"]  .rt-node-right {
        visibility: visible;
        padding-left: 16px;
    }

    .rt-dot-btn { margin: 0; }

    .rt-panel-body { grid-template-columns: 1fr; }
    .rt-panel-image-wrap { min-height: 200px; }
    .rt-panel-text { padding: 22px 22px; }

    .rt-end-cap { align-items: flex-start; justify-content: flex-start;}

    .rt-subtitle { max-width: none; }

    .rt-header { margin-bottom: 0;}
}

/* ── Video mute button ─────────────────────────────── */
.rt-panel-image-wrap {
    position: relative; /* anchor for the button */
}

.rt-mute-btn {
    position: absolute;
    bottom: 10px;
    right: 10px;
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: none;
    cursor: pointer;
    background: rgba(0, 0, 0, 0.55);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    transition: background 0.2s, transform 0.15s;
    padding: 0;
}

.rt-mute-btn:hover {
    background: rgba(0, 0, 0, 0.8);
    transform: scale(1.1);
}

.rt-mute-btn svg {
    width: 16px;
    height: 16px;
    fill: #fff;
    display: block;
    flex-shrink: 0;
}

/* Hide the 'sound on' icon when muted, and vice versa */
.rt-mute-btn .icon-muted   { display: none; }
.rt-mute-btn .icon-unmuted { display: block; }

.rt-mute-btn[data-muted="true"] .icon-muted   { display: block; }
.rt-mute-btn[data-muted="true"] .icon-unmuted { display: none; }