/* ============================================================
   Robo Kyle, HAND page
   The 3D stage is always dark (an anatomy model needs a black theatre
   whatever the site theme is doing); the panels floating on it borrow
   the site's bevelled chrome and gold numerals. Everything below the
   stage is an ordinary document page.
   ============================================================ */

/* Scrolling lands on the stage: proximity snapping pulls the page to the
   top of the model when you get near it, and leaves the document part
   alone. The 62px is the sticky site header. */
html { scroll-snap-type: y proximity; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
.hand-page { --header-h: 62px; }

/* ---------- hero ---------- */
.hand-hero {
    padding: clamp(1.2rem, 3vw, 2.2rem) clamp(1rem, 3vw, 2rem) 1.4rem;
    background: radial-gradient(120% 90% at 50% 100%,
        color-mix(in oklab, var(--brand) 14%, transparent), transparent 60%);
}
.hand-hero-row {
    max-width: 1120px; margin: 0 auto;
    display: flex; align-items: flex-end; justify-content: space-between; gap: 2rem;
}
.hand-hero h1 {
    font-size: clamp(2.4rem, 6vw, 4rem);
    letter-spacing: .18em;
    margin: 0 0 .3rem;
    font-weight: 700;
    line-height: 1;
}
.hand-hero .lede { max-width: 40rem; margin: 0; color: var(--ink-soft); font-size: 1.02rem; }
.hand-hero-side { display: flex; flex-direction: column; align-items: flex-end; gap: .9rem; flex: none; }
.hand-legend {
    display: flex; flex-wrap: wrap; justify-content: flex-end; gap: .4rem 1.1rem;
    margin: 0; padding: 0; list-style: none; max-width: 26rem;
    font-size: .74rem; letter-spacing: .14em; text-transform: uppercase; color: var(--ink-mute);
}
.hand-legend li { display: inline-flex; align-items: center; gap: .45rem; }
.hand-legend i, .layer-list i { width: 10px; height: 10px; border-radius: 50%; display: inline-block; box-shadow: 0 0 0 1px rgba(0,0,0,.3); flex: none; }
.sw-bone   { background: #efe6d0; }
.sw-muscle { background: #b0323f; }
.sw-m-arm  { background: #9a2c2c; }
.sw-m-flex { background: #b0323f; }
.sw-m-ext  { background: #8a3563; }
.sw-m-hand { background: #c9573b; }
.sw-tendon { background: #e8dfcb; }
.sw-nerve  { background: #f6dc66; }
.sw-joint  { background: #6fbfcb; }
.sw-skin   { background: #d9a68c; }
.sw-active { background: #ff7a2e; box-shadow: 0 0 6px #ff7a2e !important; }
.sw-ligament { background: #c4d6de; }
.info-kind.kind-ligament { background: #c4d6de; }

/* Peel slider: the label sits above a full-width track. */
.peel-row { grid-template-columns: 1fr auto; }
.peel-row input { grid-column: 1 / -1; }
.peel-row output { color: var(--p-gold); font-weight: 700; font-size: .8rem; }

/* Floating labels projected from the model. */
.hand-labels { position: absolute; inset: 0; z-index: 3; pointer-events: none; overflow: hidden; }
.hand-label {
    position: absolute; left: 0; top: 0; pointer-events: auto; cursor: pointer;
    padding: .18rem .5rem; margin: -.9em 0 0 .6em; white-space: nowrap;
    background: rgba(10, 13, 19, .82); color: var(--p-ink);
    border: 1px solid var(--p-line); border-left-width: 3px; border-radius: 2px;
    font-size: .72rem; font-weight: 600; letter-spacing: .02em;
    box-shadow: 0 4px 12px rgba(0,0,0,.4);
}
.hand-label::before { content: ""; position: absolute; left: -.6em; top: 50%; width: .5em; height: 1px; background: var(--p-line); }
.hand-label.kind-joint { border-left-color: #6fbfcb; }
.hand-label.kind-muscle { border-left-color: #d15461; }
.hand-label.kind-nerve { border-left-color: #f6dc66; }
.hand-label.kind-bone, .hand-label.kind-ligament { border-left-color: #efe6d0; }
.hand-label.is-selected { background: rgba(20, 26, 36, .95); color: var(--p-gold); border-color: var(--p-gold); font-size: .8rem; z-index: 1; }
.hand-jump { white-space: nowrap; }
@media (max-width: 860px) {
    .hand-hero-row { flex-direction: column; align-items: flex-start; gap: 1rem; }
    .hand-hero-side { align-items: flex-start; }
    .hand-legend { justify-content: flex-start; }
}

/* ---------- the stage ---------- */
.hand-stage {
    position: relative;
    height: calc(100vh - var(--header-h));
    height: calc(100dvh - var(--header-h));
    min-height: 560px;
    scroll-snap-align: start;
    scroll-margin-top: var(--header-h);
    background:
        radial-gradient(70% 60% at 62% 45%, #1a2432 0%, transparent 70%),
        radial-gradient(90% 90% at 20% 90%, #17130f 0%, transparent 60%),
        linear-gradient(180deg, #0b1017 0%, #090c12 100%);
    color: #e9e2d3;
    overflow: hidden;
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
    outline: none;
    /* Panels inside inherit these regardless of the page theme. */
    --p-bg: rgba(14, 18, 26, .84);
    --p-line: rgba(255,255,255,.08);
    --p-lite: rgba(255,255,255,.14);
    --p-dark: rgba(0,0,0,.6);
    --p-ink: #e9e2d3;
    --p-soft: #b8b3a6;
    --p-mute: #7c8494;
    --p-gold: #e2be55;
    --p-teal: #6fbfcb;
    --p-active: #ff7a2e;
}
.hand-stage:fullscreen { height: 100vh; min-height: 0; border: 0; }
.hand-stage:focus-visible { box-shadow: inset 0 0 0 2px var(--p-gold); }
.hand-stage canvas { display: block; width: 100% !important; height: 100% !important; touch-action: none; }
.hand-stage.is-dragging canvas { cursor: grabbing !important; }

.hand-stage .stage-loading, .hand-stage .stage-fallback {
    position: absolute; inset: 0; display: grid; place-items: center;
    text-align: center; padding: 2rem; color: var(--p-soft); pointer-events: none;
}
.hand-stage .stage-fallback { display: none; }
.hand-stage.is-ready .stage-loading { display: none; }
.hand-stage.is-broken .stage-loading { display: none; }
.hand-stage.is-broken .stage-fallback { display: grid; pointer-events: auto; }
.stage-loading .spin {
    width: 46px; height: 46px; margin: 0 auto .9rem; border-radius: 50%;
    border: 2px solid var(--p-line); border-top-color: var(--p-teal);
    animation: hand-spin 1s linear infinite;
}
@keyframes hand-spin { to { transform: rotate(360deg); } }
.stage-fallback code { color: var(--p-gold); background: none; border: 0; }

/* Tooltip that follows the pointer. */
.hand-tip {
    position: absolute; left: 0; top: 0; z-index: 6;
    padding: .35rem .65rem; pointer-events: none; white-space: nowrap;
    background: rgba(10, 13, 19, .92); color: var(--p-ink);
    border: 1px solid var(--p-lite); border-radius: 2px;
    font-size: .82rem; line-height: 1.3;
    box-shadow: 0 6px 18px rgba(0,0,0,.45);
}
.hand-tip b { display: block; font-weight: 700; }
.hand-tip span { display: block; color: var(--p-mute); font-size: .7rem; letter-spacing: .08em; text-transform: uppercase; }

/* Top toolbar: views and fullscreen. */
.hand-toolbar {
    position: absolute; top: .9rem; left: 50%; transform: translateX(-50%); z-index: 4;
    display: flex; gap: .6rem; align-items: center;
}
.toolbar-group {
    display: inline-flex; gap: .25rem; padding: .25rem;
    background: var(--p-bg); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
    border: 2px solid; border-color: var(--p-lite) var(--p-dark) var(--p-dark) var(--p-lite); border-radius: 2px;
}
.toolbar-group .hand-btn { min-height: 32px; padding: .3rem .7rem; font-size: .78rem; border-color: transparent; background: transparent; box-shadow: none; }
.toolbar-group .hand-btn:hover { background: rgba(255,255,255,.07); }

/* ---------- floating panels ---------- */
.hand-panel {
    position: absolute; top: 4.2rem; z-index: 4;
    width: min(300px, 40vw);
    max-height: calc(100% - 8.6rem);
    display: flex; flex-direction: column;
    background: var(--p-bg);
    backdrop-filter: blur(12px) saturate(1.2);
    -webkit-backdrop-filter: blur(12px) saturate(1.2);
    border: 2px solid; border-color: var(--p-lite) var(--p-dark) var(--p-dark) var(--p-lite);
    border-radius: 2px;
    box-shadow: inset 1px 1px 0 rgba(255,255,255,.06), 0 18px 40px rgba(0,0,0,.45);
    color: var(--p-ink);
    font-size: .86rem;
}
.hand-panel.panel-left  { left: 1rem; }
.hand-panel.panel-right { right: 1rem; width: min(340px, 42vw); }
.hand-panel .panel-head {
    display: flex; align-items: center; justify-content: space-between; gap: .5rem;
    padding: .6rem .85rem; border-bottom: 1px solid var(--p-line);
    font-family: var(--font-panel); font-weight: 700; font-size: 1rem; letter-spacing: .02em;
}
.hand-panel .panel-close {
    display: none; background: none; border: 0; color: var(--p-mute); font: inherit; font-size: 1.2rem; cursor: pointer; padding: 0 .2rem;
}
.hand-panel .panel-body { overflow-y: auto; overscroll-behavior: contain; padding: .7rem .85rem .9rem; scrollbar-width: thin; }
.hand-panel h4 {
    margin: .9rem 0 .4rem; font-family: var(--font-sans); font-size: .7rem; font-weight: 700;
    letter-spacing: .14em; text-transform: uppercase; color: var(--p-mute);
}
.hand-panel h4:first-child { margin-top: 0; }
.hand-panel h5 { margin: .7rem 0 .25rem; font-family: var(--font-panel); font-size: .9rem; color: var(--p-soft); font-weight: 600; }

.layer-list { display: grid; gap: .2rem; margin: 0; padding: 0; list-style: none; }
.layer-list label { display: flex; align-items: center; gap: .55rem; cursor: pointer; padding: .2rem 0; color: var(--p-ink); }
.layer-list input { accent-color: var(--p-teal); width: 15px; height: 15px; margin: 0; }

.hand-panel .range-row { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: .6rem; color: var(--p-soft); margin: .25rem 0; }
.hand-panel input[type="range"] { width: 100%; accent-color: var(--p-teal); margin: 0; }

.preset-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: .35rem; }
.hand-btn {
    display: inline-flex; align-items: center; justify-content: center; gap: .4rem;
    padding: .45rem .6rem; min-height: 36px;
    background: rgba(255,255,255,.05); color: var(--p-ink);
    border: 2px solid; border-color: var(--p-lite) var(--p-dark) var(--p-dark) var(--p-lite);
    border-radius: 2px; box-shadow: inset 1px 1px 0 rgba(255,255,255,.05);
    font: inherit; font-weight: 600; font-size: .82rem; cursor: pointer; text-align: center;
    transition: background .12s ease;
}
.hand-btn:hover, .hand-btn:focus-visible { outline: 1px solid var(--p-gold); outline-offset: -1px; }
.hand-btn:active, .hand-btn[aria-pressed="true"] {
    border-color: var(--p-dark) var(--p-lite) var(--p-lite) var(--p-dark);
    box-shadow: inset 1px 1px 0 rgba(0,0,0,.4);
    background: color-mix(in oklab, var(--p-teal) 22%, rgba(255,255,255,.04));
}
.hand-btn.wide { grid-column: 1 / -1; }
.hand-btn.accent { background: color-mix(in oklab, var(--p-teal) 18%, rgba(255,255,255,.03)); }
.btn-row { display: flex; flex-wrap: wrap; gap: .35rem; }

.jslider { display: grid; grid-template-columns: 1fr 3.2rem; grid-template-areas: "l o" "s s"; align-items: center; gap: .05rem .4rem; margin: .3rem 0; }
.jslider span { grid-area: l; color: var(--p-soft); font-size: .8rem; }
.jslider output { grid-area: o; text-align: right; font-variant-numeric: tabular-nums; color: var(--p-gold); font-weight: 700; font-size: .8rem; }
.jslider input { grid-area: s; }
.jgroup { border-top: 1px solid var(--p-line); padding-top: .2rem; margin-top: .4rem; }
.hand-panel details > summary { cursor: pointer; color: var(--p-soft); font-weight: 600; padding: .35rem 0; list-style: none; display: flex; align-items: center; gap: .4rem; }
.hand-panel details > summary::-webkit-details-marker { display: none; }
.hand-panel details > summary::before { content: "▸"; color: var(--p-mute); font-size: .8em; transition: transform .15s; }
.hand-panel details[open] > summary::before { transform: rotate(90deg); }

.chk-row { display: flex; align-items: center; gap: .5rem; margin: .3rem 0; color: var(--p-soft); cursor: pointer; }
.chk-row input { accent-color: var(--p-teal); margin: 0; }

/* Info panel. */
.info-empty { color: var(--p-soft); line-height: 1.5; }
.info-empty kbd { font: inherit; font-weight: 700; color: var(--p-ink); background: rgba(255,255,255,.08); padding: 0 .35em; border-radius: 2px; border: 1px solid var(--p-line); }
.info-kind {
    display: inline-block; font-size: .68rem; letter-spacing: .14em; text-transform: uppercase; font-weight: 700;
    padding: .18rem .5rem; border-radius: 2px; margin-bottom: .4rem; color: #0b0e14;
}
.info-kind.kind-bone   { background: #efe6d0; }
.info-kind.kind-muscle { background: #d15461; }
.info-kind.kind-nerve  { background: #f3d55b; }
.info-kind.kind-joint  { background: #6fbfcb; }
#info-body h3 { font-family: var(--font-display); font-size: 1.25rem; color: var(--p-ink); margin: 0 0 .5rem; line-height: 1.2; }
#info-body p { color: var(--p-soft); line-height: 1.55; margin: 0 0 .7rem; }
.info-rows { margin: 0; display: grid; gap: .45rem; }
.info-row { display: grid; grid-template-columns: 5.4rem 1fr; gap: .5rem; align-items: start; }
.info-row dt { font-size: .68rem; letter-spacing: .12em; text-transform: uppercase; color: var(--p-mute); padding-top: .15rem; }
.info-row dd { margin: 0; color: var(--p-ink); line-height: 1.45; }
.info-joints, .info-related { margin-top: .9rem; border-top: 1px solid var(--p-line); padding-top: .4rem; }
.info-meter { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: .6rem; margin: 0 0 .8rem; font-size: .74rem; letter-spacing: .1em; text-transform: uppercase; color: var(--p-mute); }
.info-meter i { display: block; height: 6px; background: rgba(255,255,255,.08); border-radius: 3px; overflow: hidden; position: relative; }
.info-meter i::after { content: ""; position: absolute; inset: 0; width: calc(var(--v, 0) * 100%); background: var(--p-active); box-shadow: 0 0 8px var(--p-active); transition: width .15s linear; }
.info-meter output { color: var(--p-gold); font-weight: 700; font-variant-numeric: tabular-nums; }
.link-chip {
    display: inline-block; margin: .15rem .3rem .15rem 0; padding: .25rem .6rem;
    background: rgba(255,255,255,.06); color: var(--p-ink); border: 1px solid var(--p-line); border-radius: 2px;
    font: inherit; font-size: .78rem; font-weight: 600; cursor: pointer;
}
.link-chip:hover { border-color: var(--p-gold); }
.link-chip.kind-nerve { border-left: 3px solid #f6dc66; }
.link-chip.kind-muscle { border-left: 3px solid #d15461; }

.index-search {
    width: 100%; box-sizing: border-box; margin: 0 0 .5rem;
    padding: .45rem .6rem; background: rgba(0,0,0,.35); color: var(--p-ink);
    border: 1px solid var(--p-line); border-radius: 2px; font: inherit; font-size: .85rem;
}
.index-search:focus { outline: 1px solid var(--p-gold); }
.index-group ul { list-style: none; margin: 0 0 .4rem; padding: 0 0 0 .9rem; }
.index-group li button {
    display: block; width: 100%; text-align: left; background: none; border: 0;
    color: var(--p-soft); font: inherit; font-size: .82rem; padding: .18rem .3rem; cursor: pointer; border-radius: 2px;
}
.index-group li button:hover, .index-group li button.is-hover { color: var(--p-ink); background: rgba(255,255,255,.06); }
.index-group li button.is-selected { color: var(--p-gold); font-weight: 700; }
.hand-panel .rs-num { font-size: .8em; }

/* "Working now": the muscles and nerves lit by the current movement. */
.hand-active {
    position: absolute; left: 50%; bottom: 2.6rem; transform: translateX(-50%); z-index: 3;
    max-width: min(92%, 980px);
    display: flex; flex-wrap: wrap; justify-content: center; align-items: center; gap: .3rem;
    padding: .4rem .6rem;
    background: var(--p-bg); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
    border: 2px solid; border-color: var(--p-lite) var(--p-dark) var(--p-dark) var(--p-lite); border-radius: 2px;
}
.active-label { font-size: .66rem; letter-spacing: .14em; text-transform: uppercase; color: var(--p-mute); margin-right: .4rem; }
.chip {
    display: inline-flex; align-items: center; gap: .4rem;
    padding: .22rem .55rem .22rem .4rem; border-radius: 2px;
    background: rgba(255,255,255,.05); border: 1px solid var(--p-line); color: var(--p-ink);
    font: inherit; font-size: .76rem; font-weight: 600; cursor: pointer;
}
.chip:hover { border-color: var(--p-gold); }
.chip i { width: 9px; height: 9px; border-radius: 50%; background: var(--p-active); opacity: calc(.35 + var(--v, 0) * .65); box-shadow: 0 0 calc(var(--v, 0) * 10px) var(--p-active); }
.chip.chip-nerve i { background: #f6dc66; box-shadow: 0 0 calc(var(--v, 0) * 10px) #f6dc66; }

/* Bottom hint strip + mobile panel buttons. */
.hand-hints {
    position: absolute; left: 0; right: 0; bottom: 0; z-index: 3;
    display: flex; flex-wrap: wrap; justify-content: center; gap: .3rem 1.2rem;
    padding: .5rem 1rem calc(.5rem + env(safe-area-inset-bottom, 0px));
    background: linear-gradient(180deg, transparent, rgba(6, 9, 14, .85));
    font-size: .72rem; letter-spacing: .1em; text-transform: uppercase; color: var(--p-mute);
    pointer-events: none;
}
.hand-hints b { color: var(--p-ink); font-weight: 700; }
.hand-mobile-bar { display: none; }

@media (max-width: 860px) {
    .hand-stage { height: min(82vh, 760px); min-height: 480px; }
    .hand-toolbar { top: .6rem; width: calc(100% - 1.2rem); overflow-x: auto; justify-content: flex-start; }
    .hand-panel { top: auto; bottom: 0; left: 0 !important; right: 0 !important; width: 100% !important;
        max-height: 68%; transform: translateY(102%); transition: transform .22s ease; border-width: 2px 0 0; }
    .hand-panel.is-open { transform: none; }
    .hand-panel .panel-close { display: inline-block; }
    .hand-hints { display: none; }
    .hand-active { bottom: 3.4rem; max-width: 96%; }
    .hand-mobile-bar {
        position: absolute; left: 0; right: 0; bottom: 0; z-index: 5;
        display: flex; gap: .4rem; padding: .5rem .6rem calc(.5rem + env(safe-area-inset-bottom, 0px));
        background: linear-gradient(180deg, transparent, rgba(6, 9, 14, .9));
    }
    .hand-mobile-bar .hand-btn { flex: 1; min-height: 40px; }
    .hand-mobile-bar .hand-btn[aria-expanded="true"] { border-color: var(--p-dark) var(--p-lite) var(--p-lite) var(--p-dark); background: color-mix(in oklab, var(--p-teal) 22%, transparent); }
    .hand-panel { padding-bottom: 3.4rem; }
}
@media (prefers-reduced-motion: reduce) { .hand-panel { transition: none; } .stage-loading .spin { animation: none; } }

/* ---------- document part below the stage ---------- */
.hand-doc { max-width: 720px; margin: 0 auto; padding: clamp(2rem, 5vw, 3.5rem) clamp(1rem, 3vw, 2rem) 1rem; }
.hand-doc h2 {
    font-family: var(--font-panel); font-weight: 600; font-size: 1.35rem;
    margin: 2.2rem 0 .7rem; border-top: 1px solid var(--line); padding-top: 1.3rem;
}
.hand-doc h2:first-of-type { border-top: 0; padding-top: 0; margin-top: 0; }
.hand-doc p { color: var(--ink-soft); line-height: 1.65; }
.hand-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: .6rem; margin: 1rem 0 1.4rem; padding: 0; list-style: none; }
.hand-stats li {
    text-align: center; padding: .8rem .5rem;
    background: var(--rs-well); border: 2px solid; border-color: var(--rs-dark) var(--rs-lite) var(--rs-lite) var(--rs-dark);
    border-radius: 2px; box-shadow: var(--rs-step-in);
}
.hand-stats .rs-num { display: block; font-size: 1.7rem; line-height: 1.1; }
.hand-stats span:not(.rs-num) { font-size: .72rem; letter-spacing: .14em; text-transform: uppercase; color: var(--ink-mute); }
@media (max-width: 560px) { .hand-stats { grid-template-columns: 1fr 1fr; } }
.hand-doc .controls-table { width: 100%; border-collapse: collapse; margin: .5rem 0 1rem; font-size: .95rem; display: table; }
.hand-doc .controls-table td { padding: .45rem .4rem; border-bottom: 1px solid var(--line-soft); color: var(--ink-soft); vertical-align: top; }
.hand-doc .controls-table td:first-child { color: var(--ink); font-weight: 600; white-space: nowrap; width: 11rem; }
.hand-doc pre { font-size: .84rem; line-height: 1.5; }
.hand-doc .note-panel { margin: 1.4rem 0; }