/* RoboScript project page.
   Light-first on a white ground, with the paper's blue for RoboScript and as the
   accent (its figures mark RoboScript blue), teal beside it, and the paper's orange
   kept for privileged data. Every colour is a token below, redefined for the dark
   theme, so components never name a colour themselves. */

:root,
:root[data-theme="light"] {
    color-scheme: light;
    --bg: #FFFFFF;
    --surface: rgba(255, 255, 255, .86);
    --surface-solid: #FFFFFF;
    --surface-2: #F3F6FB;
    --surface-3: #E7ECF5;
    --line: rgba(20, 32, 70, .10);
    --line-2: rgba(20, 32, 70, .19);
    --text: #111827;
    --text-2: #3F4A61;
    --muted: #667089;
    --accent: #2B5FD9;
    --accent-2: #149EAE;
    --accent-ink: #2251C4;
    --accent-rgb: 43, 95, 217;
    --accent-soft: rgba(43, 95, 217, .08);
    --blue: #2B5FD9;
    --blue-strong: #2B5FD9;
    --blue-soft: rgba(43, 95, 217, .08);
    --teal: #128A79;
    --red: #D44A43;
    --warm: #D06141;
    --base: #8A919E;
    --glow-a: rgba(20, 158, 174, .05);
    --glow-b: rgba(43, 95, 217, .06);
    --glow-c: rgba(43, 95, 217, .03);
    --shadow: 0 14px 38px rgba(20, 32, 70, .09);
    --nav-bg: rgba(255, 255, 255, .78);
    --nav-shadow: 0 6px 24px rgba(20, 32, 70, .07);
    --code-bg: #F6F8FC;
    --on-accent: #FFFFFF;
    --grid-line: rgba(20, 32, 70, .05);
    --logo-ink: #1F2937;
    --logo-blue: #2E5AA8;
}

:root[data-theme="dark"] {
    color-scheme: dark;
    --bg: #070B14;
    --surface: rgba(17, 25, 47, .66);
    --surface-solid: #0F172C;
    --surface-2: #16203B;
    --surface-3: #1E2A4A;
    --line: rgba(140, 165, 230, .14);
    --line-2: rgba(140, 165, 230, .28);
    --text: #E8ECF6;
    --text-2: #B0BAD0;
    --muted: #8892AB;
    --accent: #6F9BFF;
    --accent-2: #3FD0D4;
    --accent-ink: #8EB1FF;
    --accent-rgb: 111, 155, 255;
    --accent-soft: rgba(111, 155, 255, .14);
    --blue: #7EA6FF;
    --blue-strong: #4F7CFF;
    --blue-soft: rgba(126, 166, 255, .14);
    --teal: #3AD3B1;
    --red: #FF6B6B;
    --warm: #FF8A5C;
    --base: #7F8AA3;
    --glow-a: rgba(63, 208, 212, .07);
    --glow-b: rgba(79, 124, 255, .15);
    --glow-c: rgba(79, 124, 255, .05);
    --shadow: 0 18px 50px rgba(0, 0, 0, .45);
    --nav-bg: rgba(9, 14, 28, .62);
    --nav-shadow: 0 8px 30px rgba(0, 0, 0, .18);
    --code-bg: #0B1226;
    --on-accent: #FFFFFF;
    --grid-line: rgba(140, 165, 230, .07);
    --logo-ink: #E8ECF6;
    --logo-blue: #6F9BFF;
}

:root {
    --font-sans: "Inter Variable", Inter, system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
    --font-display: "Space Grotesk Variable", "Inter Variable", system-ui, -apple-system, "Segoe UI", sans-serif;
    --font-mono: "JetBrains Mono Variable", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    --ease: cubic-bezier(.22, .68, .32, 1);
    --radius: 1rem;
    --nav-h: 3.6rem;
}

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 1.2rem); }
[data-motion="off"] { scroll-behavior: auto; }

body {
    font-family: var(--font-sans);
    color: var(--text);
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
    transition: background-color .3s, color .3s;
}
/* one ground for the whole page: soft glows fixed to the viewport, so every section
   shares the same light instead of sitting on a block of its own */
body::before {
    content: "";
    position: fixed;
    inset: 0;
    z-index: -1;
    pointer-events: none;
    background:
        radial-gradient(75rem 55rem at 0% 0%, var(--glow-b), transparent 62%),
        radial-gradient(60rem 50rem at 100% 40%, var(--glow-a), transparent 62%),
        radial-gradient(65rem 45rem at 20% 100%, var(--glow-c), transparent 62%);
}

a { color: var(--blue); text-decoration-thickness: 1px; text-underline-offset: .18em; }
a:hover { color: var(--accent-ink); }
::selection { background: var(--accent-soft); }

p, .res-text, .fig-caption, .sec-lead { text-wrap: pretty; }
code { color: var(--blue); font-family: var(--font-mono); font-size: .86em; }
strong { color: var(--text); font-weight: 650; }

.grad {
    background: linear-gradient(100deg, var(--accent) 10%, var(--accent-2) 90%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}
.grad-cool {
    background: linear-gradient(100deg, var(--blue) 0%, var(--teal) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

/* ---------------- top bar ---------------- */
.progress-line {
    position: fixed;
    inset: 0 0 auto 0;
    height: 3px;
    z-index: 1040;
    transform-origin: 0 50%;
    transform: scaleX(var(--p, 0));
    background: linear-gradient(90deg, var(--accent), var(--accent-2), var(--blue));
    pointer-events: none;
}

.topnav {
    position: fixed;
    top: .7rem;
    left: 50%;
    z-index: 1030;
    transform: translateX(-50%);
    width: min(1120px, calc(100% - 1.4rem));
    height: var(--nav-h);
    display: flex;
    align-items: center;
    gap: .75rem;
    padding: 0 .6rem 0 1.1rem;
    border-radius: 999px;
    background: var(--nav-bg);
    border: 1px solid var(--line);
    backdrop-filter: blur(16px) saturate(140%);
    -webkit-backdrop-filter: blur(16px) saturate(140%);
    box-shadow: var(--nav-shadow);
    transition: transform .4s var(--ease), opacity .4s;
}
.topnav.is-hidden { transform: translate(-50%, -150%); opacity: 0; }
.brand { display: flex; align-items: center; gap: .5rem; flex: none; text-decoration: none; color: var(--text); }
.brand:hover { color: var(--text); }
/* the logo symbol in index.html: "Robo" is drawn in `color`, "Script" in `fill` */
.logo { display: block; width: auto; aspect-ratio: 697.2 / 125; color: var(--logo-ink); fill: var(--logo-blue); }
.brand .logo { height: 1.75rem; }
.nav-links {
    display: flex;
    gap: .15rem;
    margin: 0 auto;
    overflow-x: auto;
    scrollbar-width: none;
}
.nav-links::-webkit-scrollbar { display: none; }
.nav-links a {
    color: var(--text-2);
    text-decoration: none;
    font-size: .88rem;
    font-weight: 500;
    padding: .38rem .8rem;
    border-radius: 999px;
    white-space: nowrap;
    transition: color .2s, background .2s;
}
.nav-links a:hover { color: var(--text); background: var(--surface-2); }
.nav-links a.is-on { color: var(--text); background: var(--accent-soft); box-shadow: inset 0 0 0 1px rgba(var(--accent-rgb), .35); }
.nav-tools { display: flex; gap: .35rem; flex: none; }
.icon-btn {
    display: inline-flex;
    align-items: center;
    gap: .35rem;
    height: 2.3rem;
    min-width: 2.3rem;
    justify-content: center;
    padding: 0 .65rem;
    border-radius: 999px;
    border: 1px solid var(--line);
    background: var(--surface-2);
    color: var(--text-2);
    font-size: .8rem;
    font-weight: 500;
    transition: color .2s, border-color .2s, background .2s;
}
.icon-btn:hover { color: var(--text); border-color: var(--line-2); }
.icon-btn svg { width: 1rem; height: 1rem; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
/* the button shows the theme it switches to */
.theme-btn .sun, [data-theme="dark"] .theme-btn .moon { display: none; }
[data-theme="dark"] .theme-btn .sun { display: block; }
.motion-btn .on-ico, [data-motion="off"] .motion-btn .off-ico { display: none; }
[data-motion="off"] .motion-btn .on-ico { display: block; }
.menu-btn { display: none; }
.menu-btn .close-ico, .topnav.is-open .menu-btn .open-ico { display: none; }
.topnav.is-open .menu-btn .close-ico { display: block; }

.to-top {
    position: fixed;
    right: 1.1rem;
    bottom: 1.1rem;
    z-index: 1020;
    width: 2.8rem;
    height: 2.8rem;
    border-radius: 999px;
    border: 1px solid var(--line-2);
    background: var(--nav-bg);
    backdrop-filter: blur(12px);
    color: var(--text);
    display: grid;
    place-items: center;
    opacity: 0;
    transform: translateY(12px);
    pointer-events: none;
    transition: opacity .3s, transform .3s var(--ease);
}
.to-top.is-on { opacity: 1; transform: none; pointer-events: auto; }
.to-top svg { width: 1.1rem; height: 1.1rem; fill: none; stroke: currentColor; stroke-width: 2.2; stroke-linecap: round; stroke-linejoin: round; }

/* ---------------- hero ---------------- */
.hero {
    position: relative;
    isolation: isolate;
    overflow: hidden;
    padding: calc(var(--nav-h) + 4.5rem) 0 3rem;
}
#heroCanvas { position: absolute; inset: 0; z-index: -1; width: 100%; height: 100%; }
.hero-grid {
    position: absolute;
    inset: 0;
    z-index: -2;
    background-image:
        linear-gradient(var(--grid-line) 1px, transparent 1px),
        linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
    background-size: 56px 56px;
    mask-image: radial-gradient(ellipse at 50% 40%, #000 30%, transparent 75%);
    -webkit-mask-image: radial-gradient(ellipse at 50% 40%, #000 30%, transparent 75%);
}
.hero-inner { max-width: 1040px; text-align: center; }
.hero-brand {
    display: inline-flex;
    align-items: center;
    gap: .7rem;
    margin: 0 0 1.4rem;
    padding: .5rem 1rem .5rem .55rem;
    border-radius: 999px;
    border: 1px solid var(--line);
    background: var(--surface);
    box-shadow: var(--nav-shadow);
}
.hero-brand .logo { height: 2.5rem; }

.hero-title {
    font-family: var(--font-display);
    font-weight: 700;
    letter-spacing: -.035em;
    line-height: 1.05;
    font-size: clamp(2.3rem, 5.2vw + .4rem, 4.6rem);
    margin: 0 0 1.1rem;
}
.hero-title .line { display: block; font-size: .62em; font-weight: 600; letter-spacing: -.025em; color: var(--text); margin-top: .35rem; }
.hero-sub {
    font-size: clamp(1.05rem, 1.2vw + .7rem, 1.45rem);
    color: var(--text-2);
    max-width: 760px;
    margin: 0 auto 2rem;
    line-height: 1.45;
}
.hero-sub .hl { color: var(--text); font-weight: 600; white-space: nowrap; }

.authors { font-size: 1rem; margin-bottom: .35rem; }
.authors a, .authors .au { white-space: nowrap; }
.authors a { color: var(--text); text-decoration: none; border-bottom: 1px solid var(--line-2); }
.authors a:hover { color: var(--accent-ink); border-color: currentColor; }
.authors sup { color: var(--muted); }
.affil { color: var(--muted); font-size: .9rem; margin-bottom: .2rem; }

.cta { display: flex; flex-wrap: wrap; justify-content: center; gap: .6rem; margin-top: 1.8rem; }
.pill {
    display: inline-flex;
    align-items: center;
    gap: .45em;
    padding: .62rem 1.25rem;
    border-radius: 999px;
    font-size: .95rem;
    font-weight: 600;
    text-decoration: none;
    color: var(--text);
    border: 1px solid var(--line-2);
    background: var(--surface);
    backdrop-filter: blur(10px);
    transition: transform .2s var(--ease), border-color .2s, background .2s, box-shadow .2s, color .2s;
}
.pill:hover { color: var(--text); transform: translateY(-2px); border-color: var(--accent); box-shadow: 0 10px 26px rgba(var(--accent-rgb), .16); }
.pill svg { width: 1.05em; height: 1.05em; fill: currentColor; }
.pill.primary {
    color: var(--on-accent);
    border-color: transparent;
    background: linear-gradient(110deg, var(--accent), var(--accent-2));
    box-shadow: 0 10px 30px rgba(var(--accent-rgb), .28);
}
.pill.primary:hover { color: var(--on-accent); box-shadow: 0 14px 36px rgba(var(--accent-rgb), .38); border-color: transparent; }
/* a link that has no target yet still reads as a pill, just a quieter one */
.pill.is-soon { opacity: .55; pointer-events: none; }
.pill .soon {
    font-size: .68em;
    padding: .06rem .42rem;
    border-radius: 999px;
    background: var(--surface-3);
    color: var(--text-2);
}

.scroll-cue {
    position: absolute;
    left: 50%;
    bottom: 1.4rem;
    transform: translateX(-50%);
    width: 1.5rem;
    height: 2.4rem;
    border-radius: 999px;
    border: 2px solid var(--line-2);
}
.scroll-cue::after {
    content: "";
    position: absolute;
    left: 50%;
    top: .45rem;
    width: .3rem;
    height: .5rem;
    margin-left: -.15rem;
    border-radius: 999px;
    background: var(--accent);
    animation: cue 1.8s var(--ease) infinite;
}
@keyframes cue { 0% { transform: translateY(0); opacity: 1; } 70% { transform: translateY(.9rem); opacity: 0; } 100% { opacity: 0; } }

/* ---------------- rollout marquee ---------------- */
.marquee {
    position: relative;
    padding: .5rem 0 3rem;
    overflow: hidden;
    mask-image: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
    -webkit-mask-image: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
}
.marquee-row { display: flex; width: max-content; gap: .7rem; margin-bottom: .7rem; animation: marquee var(--dur, 90s) linear infinite; }
.marquee-row.rev { animation-direction: reverse; }
.marquee:hover .marquee-row { animation-play-state: paused; }
.marquee-row img {
    height: clamp(84px, 9vw, 128px);
    aspect-ratio: 4 / 3;
    object-fit: cover;
    border-radius: .7rem;
    border: 1px solid var(--line);
    background: var(--surface-2);
}
@keyframes marquee { to { transform: translateX(-50%); } }

/* ---------------- sections ---------------- */
.sec { position: relative; padding: 5rem 0; }
.sec-head { max-width: 860px; margin-bottom: 2.6rem; }
.sec-head.center { margin-inline: auto; text-align: center; }
.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: .6rem;
    font-family: var(--font-mono);
    font-size: 1.3rem;
    font-weight: 600;
    letter-spacing: .14em;
    text-transform: uppercase;
    color: var(--accent-ink);
    margin-bottom: .9rem;
}
.eyebrow .num {
    display: inline-grid;
    place-items: center;
    min-width: 2.9rem;
    height: 2.2rem;
    padding: 0 .5rem;
    border-radius: .5rem;
    background: var(--accent-soft);
    border: 1px solid rgba(var(--accent-rgb), .3);
    letter-spacing: .04em;
}
.sec-title {
    font-family: var(--font-display);
    font-weight: 700;
    letter-spacing: -.03em;
    line-height: 1.08;
    font-size: clamp(2rem, 3.4vw + .6rem, 3.3rem);
    margin: 0 0 1rem;
}
.sec-lead { font-size: 1.08rem; line-height: 1.7; color: var(--text-2); margin: 0; }

.res-head {
    font-family: var(--font-display);
    font-weight: 650;
    font-size: 1.3rem;
    letter-spacing: -.015em;
    margin: 0 0 .9rem;
    color: var(--text);
}
.res-text { font-size: .98rem; line-height: 1.75; color: var(--text-2); }
.res-takeaway {
    font-size: .98rem;
    line-height: 1.7;
    color: var(--text-2);
    border: 1px solid var(--line);
    border-left: 3px solid var(--accent);
    background: linear-gradient(90deg, var(--accent-soft), transparent 70%);
    border-radius: 0 .7rem .7rem 0;
    padding: .9rem 1.15rem;
    margin: 0 0 1.2rem;
}
.section-block + .section-block { margin-top: 4.5rem; }

/* glass card with a spotlight that follows the pointer (fx.js sets --mx/--my) */
.glass {
    position: relative;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: var(--surface);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    transition: border-color .25s, transform .25s var(--ease), box-shadow .25s;
}
.glass::before {
    content: "";
    position: absolute;
    inset: 0;
    border-radius: inherit;
    pointer-events: none;
    opacity: 0;
    transition: opacity .3s;
    background: radial-gradient(420px circle at var(--mx, 50%) var(--my, 50%), rgba(var(--accent-rgb), .08), transparent 45%);
}
.glass:hover::before { opacity: 1; }
.glass:hover { border-color: var(--line-2); }
.lift:hover { transform: translateY(-4px); box-shadow: var(--shadow); }

/* a slowly turning gradient border */
@property --angle { syntax: "<angle>"; inherits: false; initial-value: 0deg; }
.halo { position: relative; isolation: isolate; }
.halo::after {
    content: "";
    position: absolute;
    inset: -1px;
    z-index: -1;
    border-radius: inherit;
    padding: 1.5px;
    background: conic-gradient(from var(--angle), var(--accent), var(--blue), var(--teal), var(--accent-2), var(--accent));
    -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    animation: turn 8s linear infinite;
}
@keyframes turn { to { --angle: 360deg; } }

/* ---------------- figures and video ---------------- */
.fig-card {
    position: relative;
    margin: 0 auto;
    padding: clamp(.6rem, 1.5vw, 1.2rem);
    border-radius: var(--radius);
    background: #fff;
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
    cursor: zoom-in;
    transition: transform .3s var(--ease), box-shadow .3s;
}
.fig-card:hover { transform: translateY(-3px); }
.fig-card img { display: block; width: 100%; height: auto; }
.fig-card .zoom-hint {
    position: absolute;
    right: .7rem;
    top: .7rem;
    font-size: .72rem;
    font-weight: 600;
    color: #fff;
    background: rgba(12, 18, 36, .72);
    border-radius: 999px;
    padding: .2rem .6rem;
    opacity: 0;
    transition: opacity .2s;
}
.fig-card:hover .zoom-hint { opacity: 1; }
.fig-caption { color: var(--muted); font-size: .9rem; line-height: 1.65; margin: 1rem auto 0; }
.fig-caption strong { color: var(--text-2); }

.cinema { border-radius: calc(var(--radius) + 2px); padding: 2px; }
.cinema video { display: block; width: 100%; height: auto; border-radius: var(--radius); background: #000; }
.video-caption { color: var(--muted); font-size: .9rem; text-align: center; margin: 1.1rem 0 0; }

/* ---------------- chips that explain themselves ----------------
   Hover previews, click pins, and the panel under them keeps a minimum height
   so nothing below jumps. */
.chip {
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: .45rem;
    font-size: .88rem;
    font-weight: 500;
    padding: .45rem .9rem;
    margin: .22rem;
    border-radius: 999px;
    background: var(--surface-2);
    color: var(--text-2);
    border: 1px solid var(--line);
    transition: background .2s, color .2s, border-color .2s, transform .2s var(--ease);
}
.chip:hover, .chip:focus-visible { color: var(--text); border-color: var(--line-2); transform: translateY(-1px); }
.chip.is-on { background: var(--blue-soft); border-color: var(--blue); color: var(--text); }
.chip-desc {
    max-width: 820px;
    margin: 1.1rem auto 0;
    min-height: 5.2em;
    color: var(--text-2);
    font-size: .95rem;
    line-height: 1.65;
}
.chip-desc strong { color: var(--text); }
@keyframes chip-flash {
    0% { box-shadow: 0 0 0 0 rgba(var(--accent-rgb), 0); }
    40% { box-shadow: 0 0 0 4px rgba(var(--accent-rgb), .3); border-color: var(--accent); }
    100% { box-shadow: 0 0 0 0 rgba(var(--accent-rgb), 0); }
}
.chip.flash { animation: chip-flash .7s ease-out both; }

/* data tiers: deployable (D) and privileged (P), coloured as in the paper */
.tier {
    display: inline-grid;
    place-items: center;
    min-width: 1.3rem;
    height: 1.3rem;
    padding: 0 .25rem;
    border-radius: .35rem;
    font-size: .72rem;
    font-weight: 700;
    color: #fff;
    vertical-align: .05em;
}
.tier-d { background: #1A8C7A; }
.tier-p { background: #D06141; }

/* ---------------- equations ---------------- */
.eq-card { height: 100%; padding: 1.1rem 1.3rem; }
.eq-card .eq-lab {
    font-family: var(--font-mono);
    font-size: .74rem;
    font-weight: 600;
    letter-spacing: .08em;
    text-transform: uppercase;
    color: var(--accent-ink);
    margin-bottom: .5rem;
}
.eq-card .eq { overflow-x: auto; overflow-y: hidden; padding: .3rem 0; color: var(--text); }
.eq-card p { font-size: .88rem; color: var(--muted); margin: .5rem 0 0; line-height: 1.55; }

/* ---------------- Task Memory, shown as an editor window ---------------- */
.editor { overflow: hidden; background: var(--code-bg); }
.editor-bar {
    display: flex;
    align-items: center;
    gap: .45rem;
    padding: .7rem 1rem;
    border-bottom: 1px solid var(--line);
    background: var(--surface-2);
    font-family: var(--font-mono);
    font-size: .78rem;
    color: var(--muted);
}
.editor-bar i { width: .7rem; height: .7rem; border-radius: 999px; display: inline-block; }
.editor-bar i:nth-child(1) { background: #FF5F57; }
.editor-bar i:nth-child(2) { background: #FEBC2E; }
.editor-bar i:nth-child(3) { background: #28C840; }
.editor-bar span { margin-left: .6rem; }
.editor-bar .frozen { margin-left: auto; color: var(--blue); }
.memory { padding: .3rem 1.2rem .6rem; font-size: .88rem; }
.memory-row {
    display: grid;
    grid-template-columns: 9.5rem minmax(0, 1fr);
    gap: 1.1rem;
    padding: .85rem 0;
}
.memory-row + .memory-row { border-top: 1px dashed var(--line-2); }
.memory-key b { display: block; font-family: var(--font-mono); color: var(--accent-ink); font-size: .78rem; letter-spacing: .06em; }
.memory-key span { display: block; color: var(--muted); font-size: .74rem; line-height: 1.4; margin-top: .15rem; }
.memory-val { line-height: 1.6; color: var(--text-2); }
.memory-val .mono, .memory-val code { font-family: var(--font-mono); font-size: .76rem; color: inherit; }
.memory-val .add { color: var(--blue); }
.memory-val .flow { display: flex; flex-wrap: wrap; gap: .3rem .35rem; align-items: center; margin-bottom: .45rem; }
.memory-val .flow span {
    font-family: var(--font-mono);
    font-size: .74rem;
    background: var(--surface-2);
    border: 1px solid var(--line);
    border-radius: .35rem;
    padding: .1rem .45rem;
    color: var(--text-2);
}
.memory-val .flow span.add { border-color: var(--blue); color: var(--blue); background: var(--blue-soft); }
.memory-val .flow i { color: var(--muted); font-style: normal; }
.memory-legend { font-size: .85rem; color: var(--muted); margin-top: .8rem; }
.memory-legend .add { color: var(--blue); font-weight: 600; }

/* ---------------- the idea in three cards, and the abstract folded away ---------------- */
.idea { height: 100%; padding: 1.3rem 1.35rem; display: flex; flex-direction: column; gap: .3rem; }
.idea svg {
    width: 2.6rem;
    height: 2.6rem;
    padding: .55rem;
    margin-bottom: .55rem;
    border-radius: .75rem;
    background: var(--accent-soft);
    fill: none;
    stroke: var(--accent);
    stroke-width: 1.8;
    stroke-linecap: round;
    stroke-linejoin: round;
}
.idea b { font-family: var(--font-display); font-size: 1.14rem; font-weight: 650; letter-spacing: -.01em; color: var(--text); }
.idea span { color: var(--muted); font-size: .92rem; line-height: 1.5; }

.fold { max-width: 900px; margin: 1.8rem auto 0; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.fold summary {
    display: flex;
    align-items: center;
    gap: .7rem;
    padding: .9rem 1.25rem;
    cursor: pointer;
    list-style: none;
    font-weight: 600;
    color: var(--text);
}
.fold summary::-webkit-details-marker { display: none; }
.fold summary::before {
    content: "";
    width: .5rem;
    height: .5rem;
    border-right: 2px solid var(--muted);
    border-bottom: 2px solid var(--muted);
    transform: rotate(-45deg);
    transition: transform .2s;
}
.fold[open] summary::before { transform: rotate(45deg); }
.fold p { margin: 0; padding: 0 1.4rem 1.3rem; color: var(--text-2); font-size: .98rem; line-height: 1.8; }

/* ---------------- equations, three in a row ---------------- */
.eq-row { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .8rem; }
.eq-card small { display: block; color: var(--muted); font-size: .8rem; }
.eq-row + .section-block { margin-top: 4.5rem; }

/* ---------------- real robot ----------------
   One row per task: its name and instruction in a narrow column, then three of
   its rollouts side by side; rows split by a hairline. */
.real-tasks { display: grid; gap: .8rem; }
.real-row { display: grid; grid-template-columns: 10.5rem minmax(0, 1fr); gap: 1.1rem; align-items: center; }
.real-row + .real-row { padding-top: .8rem; border-top: 1px solid var(--line); }
.real-label b { display: block; font-family: var(--font-display); font-size: 1.08rem; font-weight: 650; letter-spacing: -.01em; color: var(--text); }
.real-label span { display: block; margin-top: .3rem; color: var(--muted); font-size: .82rem; line-height: 1.45; }
.real-trio { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .6rem; }
.real-clip {
    position: relative;
    display: block;
    aspect-ratio: 16 / 9;
    padding: 0;
    border: 1px solid var(--line);
    border-radius: .7rem;
    overflow: hidden;
    background: var(--surface-2);
    cursor: zoom-in;
    transition: border-color .2s;
}
.real-clip:hover { border-color: var(--accent); }
.real-clip:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.real-clip img, .real-clip video { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; display: block; }
.real-clip video { opacity: 0; transition: opacity .3s; }
.real-clip video.is-live { opacity: 1; }

/* sim to real in three numbered steps */
.steps { list-style: none; counter-reset: step; display: grid; gap: .8rem; margin: 0; padding: 0; }
.steps li {
    counter-increment: step;
    display: grid;
    grid-template-columns: 2.6rem minmax(0, 1fr);
    column-gap: 1rem;
    align-items: center;
    padding: .95rem 1.15rem;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: var(--surface);
}
.steps li::before {
    content: counter(step);
    grid-row: span 2;
    display: grid;
    place-items: center;
    width: 2.6rem;
    height: 2.6rem;
    border-radius: 999px;
    font-family: var(--font-display);
    font-weight: 700;
    color: var(--on-accent);
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
}
.steps b { font-family: var(--font-display); font-size: 1.1rem; font-weight: 650; color: var(--text); }
.steps span { color: var(--muted); font-size: .9rem; }

/* ---------------- analysis figures behind tabs ---------------- */
.fig-tabs { display: flex; flex-wrap: wrap; gap: .4rem; margin-bottom: 1rem; }
.fig-tabs button {
    font-size: .85rem;
    font-weight: 500;
    padding: .4rem .95rem;
    border-radius: 999px;
    border: 1px solid var(--line);
    background: var(--surface-2);
    color: var(--text-2);
    transition: background .2s, color .2s, border-color .2s;
}
.fig-tabs button:hover { color: var(--text); border-color: var(--line-2); }
.fig-tabs button.is-on { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.fig-pane[hidden] { display: none; }

/* ---------------- tables ---------------- */
.table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }
.table-card { padding: .4rem 1rem .6rem; }
.rt {
    width: 100%;
    border-collapse: collapse;
    font-size: .88rem;
    font-variant-numeric: tabular-nums;
    color: var(--text-2);
}
.rt th, .rt td { padding: .5rem .6rem; white-space: nowrap; }
.rt thead th {
    font-size: .74rem;
    font-weight: 600;
    letter-spacing: .04em;
    text-transform: uppercase;
    color: var(--muted);
    border-bottom: 1px solid var(--line-2);
    vertical-align: bottom;
}
.rt thead tr.split th { border-bottom: 1px solid var(--line-2); }
.rt thead .nocase { text-transform: none; }
.rt tbody td { border-bottom: 1px solid var(--line); }
.rt tbody tr:last-child td { border-bottom: 0; }
.rt .num { text-align: right; }
.rt .ctr { text-align: center; }
.rt tr.block td {
    background: var(--surface-2);
    color: var(--text);
    font-weight: 650;
    font-size: .8rem;
    letter-spacing: .02em;
}
.rt tr.group td { color: var(--muted); font-style: italic; font-size: .8rem; padding-top: .7rem; }
.rt td.name { padding-left: 1.3rem; color: var(--text); }
.rt tr.ours td { background: var(--blue-soft); }
.rt tr.ours td.name { font-weight: 650; color: var(--blue); }
.rt .yes { color: var(--teal); font-weight: 700; }
.rt .no { color: var(--muted); opacity: .6; }
.rt .best { font-weight: 750; color: var(--text); }
.rt .second { text-decoration: underline; text-underline-offset: .2em; }
.rt .muted { color: var(--muted); }

/* a value with a thin bar under it, so a column reads as a chart */
.vbar { display: inline-flex; flex-direction: column; align-items: flex-end; min-width: 3.8rem; gap: 4px; }
.vbar i { display: block; height: 4px; width: 3.8rem; border-radius: 2px; background: var(--surface-3); overflow: hidden; }
.vbar i::before {
    content: "";
    display: block;
    height: 100%;
    width: calc(var(--v) * 1%);
    border-radius: 2px;
    background: var(--base);
    transform-origin: left center;
    transform: scaleX(0);
    transition: transform 1s cubic-bezier(.2, .78, .3, 1) var(--d, 0s);
}
.rt tr.ours .vbar i::before { background: linear-gradient(90deg, var(--blue), var(--teal)); }
.is-in .vbar i::before { transform: none; }

.table-note { font-size: .82rem; color: var(--muted); margin-top: .8rem; line-height: 1.6; }

/* ---------------- segmented control and category chips (rollout wall) ---------------- */
.seg {
    display: inline-flex;
    padding: .2rem;
    border-radius: 999px;
    background: var(--surface-2);
    border: 1px solid var(--line);
    gap: .1rem;
}
.seg button {
    border: 0;
    background: transparent;
    color: var(--muted);
    font-size: .82rem;
    font-weight: 500;
    padding: .32rem .85rem;
    border-radius: 999px;
    transition: background .2s, color .2s, box-shadow .2s;
}
.seg button:hover { color: var(--text); }
.seg button.is-on { background: var(--surface-3); color: var(--text); box-shadow: inset 0 0 0 1px var(--line-2); }

.cat-chips { display: flex; flex-wrap: wrap; gap: .4rem; }
.cat-chip {
    font-size: .82rem;
    font-weight: 500;
    padding: .34rem .85rem;
    border-radius: 999px;
    border: 1px solid var(--line);
    background: var(--surface-2);
    color: var(--text-2);
    transition: background .2s, color .2s, border-color .2s;
}
.cat-chip:hover { border-color: var(--line-2); color: var(--text); }
.cat-chip.is-on { background: var(--accent-soft); border-color: var(--accent); color: var(--text); }
.cat-chip .n { opacity: .6; margin-left: .4rem; font-variant-numeric: tabular-nums; }

/* ---------------- rollouts ----------------
   Every episode is its own tile. */
.ro-tabs { display: flex; flex-wrap: wrap; gap: .5rem; margin-bottom: 1.2rem; }
.ro-tab {
    display: inline-flex;
    align-items: center;
    gap: .55rem;
    padding: .65rem 1.15rem;
    border-radius: .9rem;
    border: 1px solid var(--line);
    background: var(--surface-2);
    color: var(--text-2);
    font-weight: 600;
    font-size: .95rem;
    transition: border-color .2s, color .2s, background .2s, transform .2s var(--ease);
}
.ro-tab:hover { color: var(--text); border-color: var(--line-2); transform: translateY(-1px); }
.ro-tab .n {
    font-family: var(--font-mono);
    font-size: .74rem;
    font-weight: 600;
    padding: .1rem .45rem;
    border-radius: 999px;
    background: var(--surface-3);
    color: var(--text-2);
}
.ro-tab.is-on {
    color: var(--text);
    border-color: transparent;
    background: linear-gradient(var(--surface-2), var(--surface-2)) padding-box,
                linear-gradient(110deg, var(--accent), var(--blue)) border-box;
    border: 1px solid transparent;
}
.ro-tab.is-on .n { background: var(--accent-soft); color: var(--accent-ink); }
.ro-tab .dot { width: .5rem; height: .5rem; border-radius: 999px; background: var(--muted); }
.ro-tab[data-k="real"] .dot { background: var(--warm); }
.ro-tab[data-k="robotwin"] .dot { background: var(--blue); }
.ro-tab[data-k="robodojo"] .dot { background: var(--teal); }

.ro-bar { display: flex; flex-wrap: wrap; gap: .6rem 1rem; align-items: center; margin-bottom: 1rem; min-height: 2.4rem; }
.ro-bar .showing { margin-left: auto; font-size: .82rem; color: var(--muted); font-variant-numeric: tabular-nums; }
.ro-note { font-size: .92rem; color: var(--text-2); line-height: 1.65; margin: 0 0 1.2rem; max-width: 900px; }

.wall {
    position: relative;
    max-height: min(80vh, 780px);
    overflow-y: auto;
    padding: .2rem .4rem 2.5rem .2rem;
    margin-right: -.4rem;
    scrollbar-width: thin;
    scrollbar-color: var(--line-2) transparent;
    mask-image: linear-gradient(#000 calc(100% - 3rem), transparent);
    -webkit-mask-image: linear-gradient(#000 calc(100% - 3rem), transparent);
}
.wall-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(168px, 1fr)); gap: .65rem; }
.real-group + .real-group { margin-top: 2rem; }
.real-head { display: flex; align-items: baseline; gap: .7rem; margin-bottom: .8rem; }
.real-head h4 { font-family: var(--font-display); font-size: 1.2rem; font-weight: 650; margin: 0; }
.real-head span { color: var(--muted); font-size: .85rem; }
.real-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: .7rem; }

.tile {
    position: relative;
    display: block;
    width: 100%;
    padding: 0;
    border: 1px solid var(--line);
    border-radius: .75rem;
    overflow: hidden;
    aspect-ratio: 4 / 3;
    background: var(--surface-2);
    cursor: zoom-in;
    color: #fff;
    text-align: left;
    animation: tile-in .5s var(--ease) both;
    animation-delay: calc(var(--i, 0) * 18ms);
    transition: transform .25s var(--ease), box-shadow .25s, border-color .25s;
}
.tile.wide { aspect-ratio: 16 / 9; }
.tile:hover { transform: translateY(-3px) scale(1.02); border-color: var(--accent); box-shadow: var(--shadow); z-index: 1; }
.tile:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.tile img, .tile video { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; display: block; }
.tile video { opacity: 0; transition: opacity .3s; }
.tile video.is-live { opacity: 1; }
.tile::after {
    content: "";
    position: absolute;
    inset: auto 0 0 0;
    height: 55%;
    background: linear-gradient(transparent, rgba(5, 8, 18, .82));
    pointer-events: none;
}
.tile-name {
    position: absolute;
    left: .6rem;
    right: .6rem;
    bottom: .45rem;
    z-index: 1;
    font-size: .76rem;
    font-weight: 600;
    line-height: 1.3;
    text-shadow: 0 1px 2px rgba(0, 0, 0, .6);
    overflow-wrap: anywhere;
}
.tile-name small { display: block; font-weight: 500; opacity: .75; font-size: .68rem; font-family: var(--font-mono); }
.tile-tag, .tile-sr {
    position: absolute;
    top: .45rem;
    z-index: 1;
    font-size: .64rem;
    font-weight: 700;
    letter-spacing: .03em;
    padding: .12rem .45rem;
    border-radius: 999px;
    backdrop-filter: blur(6px);
}
.tile-tag { left: .45rem; background: rgba(8, 12, 26, .62); color: #fff; }
.tile-tag.clean { box-shadow: inset 0 0 0 1px rgba(126, 166, 255, .7); }
.tile-tag.random { box-shadow: inset 0 0 0 1px rgba(58, 211, 177, .8); }
.tile-sr { right: .45rem; background: rgba(255, 255, 255, .9); color: #121829; }
.tile.flash { animation: tile-flash 1.8s ease-out; }

/* a RoboTwin task: its episodes stacked like cards behind the one playing */
.wall-grid.decks { grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 1.2rem 1rem; padding: .6rem .6rem 0 0; }
.tile.deck {
    --deck: 5px -5px 0 -1px var(--surface-2), 5px -5px 0 0 var(--line-2),
            10px -10px 0 -2px var(--surface-2), 10px -10px 0 -1px var(--line);
    cursor: pointer;
    box-shadow: var(--deck);
}
.tile.deck:hover { box-shadow: var(--deck), var(--shadow); }
.tile.deck .tile-name { right: 2.6rem; }
.tile-dots { position: absolute; right: .6rem; bottom: .62rem; z-index: 1; display: flex; gap: 4px; }
.tile-dots i { width: 6px; height: 6px; border-radius: 50%; background: rgba(255, 255, 255, .45); }
.tile-dots i.on { background: #fff; }
.tile.dealt { animation: deal .35s var(--ease); }
@keyframes deal { from { transform: translate(6px, -6px) rotate(1.2deg); opacity: .6; } to { transform: none; opacity: 1; } }
@keyframes tile-flash { 0%, 60% { box-shadow: 0 0 0 3px var(--accent); } 100% { box-shadow: 0 0 0 0 transparent; } }
@keyframes tile-in { from { opacity: 0; transform: translateY(14px) scale(.98); } to { opacity: 1; transform: none; } }

.tile.is-ph { cursor: default; }
.tile.is-ph img, .tile.is-ph video { filter: blur(6px) saturate(.6) brightness(.6); transform: scale(1.08); }
.tile.is-ph:hover { transform: none; border-color: var(--line); box-shadow: none; }
.ph-note {
    position: absolute;
    inset: 0;
    z-index: 1;
    display: grid;
    place-items: center;
    text-align: center;
    font-size: .85rem;
    font-weight: 600;
    color: #fff;
}
.ph-note small { display: block; font-weight: 500; opacity: .8; font-size: .72rem; }
.badge-ph {
    position: absolute;
    left: .5rem;
    top: .5rem;
    z-index: 2;
    font-size: .64rem;
    font-weight: 700;
    letter-spacing: .05em;
    color: #fff;
    background: var(--accent);
    border-radius: 999px;
    padding: .12rem .5rem;
}

/* ---------------- lightbox ---------------- */
.lightbox {
    width: min(1200px, 94vw);
    max-height: 92vh;
    padding: 0;
    border: 1px solid var(--line-2);
    border-radius: var(--radius);
    background: var(--surface-solid);
    color: var(--text);
    box-shadow: 0 30px 80px rgba(0, 0, 0, .6);
}
.lightbox::backdrop { background: rgba(3, 6, 14, .78); backdrop-filter: blur(6px); }
.lightbox[open] { animation: lb-in .3s var(--ease); }
@keyframes lb-in { from { opacity: 0; transform: translateY(16px) scale(.98); } to { opacity: 1; transform: none; } }
.lb-stage { position: relative; background: #000; display: grid; place-items: center; }
.lb-stage.is-fig { background: #fff; }
/* clips are small (320x240 in simulation), so they are scaled up to the dialog */
.lb-stage video, .lb-stage img { display: block; width: 100%; height: auto; max-height: 78vh; object-fit: contain; }
.lb-foot { display: flex; align-items: center; gap: .8rem; padding: .8rem 1rem; }
.lb-cap { flex: 1; font-size: .9rem; color: var(--text-2); line-height: 1.5; }
.lb-cap b { color: var(--text); }
.lb-btn {
    width: 2.4rem;
    height: 2.4rem;
    border-radius: 999px;
    border: 1px solid var(--line-2);
    background: var(--surface-2);
    color: var(--text);
    display: grid;
    place-items: center;
    flex: none;
}
.lb-btn:hover { border-color: var(--accent); }
.lb-btn[hidden] { display: none; }
.lb-btn svg { width: 1.05rem; height: 1.05rem; fill: none; stroke: currentColor; stroke-width: 2.2; stroke-linecap: round; stroke-linejoin: round; }

/* ---------------- BibTeX ---------------- */
.bib-wrap { position: relative; }
pre.bibtex {
    background: var(--code-bg);
    color: var(--text-2);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1.3rem 1.5rem;
    font-family: var(--font-mono);
    font-size: .85rem;
    line-height: 1.7;
    white-space: pre-wrap;
    overflow-wrap: anywhere;
    margin: 0;
}
.copy-btn {
    position: absolute;
    top: .7rem;
    right: .7rem;
    font-size: .78rem;
    font-weight: 600;
    border-radius: 999px;
    border: 1px solid var(--line-2);
    background: var(--surface-2);
    color: var(--text-2);
    padding: .25rem .8rem;
}
.copy-btn:hover { color: var(--text); border-color: var(--accent); }

/* ---------------- footer ---------------- */
.site-foot { padding: 3rem 0 4rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .88rem; }
.foot-brand { display: inline-flex; align-items: center; gap: .5rem; margin-bottom: .5rem; }
.foot-brand .logo { height: 1.7rem; }

/* ---------------- scroll reveal ---------------- */
.reveal {
    opacity: 0;
    transform: translateY(28px);
    filter: blur(6px);
    transition: opacity .9s var(--ease) var(--rise-delay, 0s),
                transform .9s var(--ease) var(--rise-delay, 0s),
                filter .9s var(--ease) var(--rise-delay, 0s);
}
.reveal.is-in { opacity: 1; transform: none; filter: none; }

/* ---------------- motion off ----------------
   Set from prefers-reduced-motion on first visit, then by the Motion button. */
[data-motion="off"] .reveal { opacity: 1; transform: none; filter: none; transition: none; }
[data-motion="off"] .marquee-row,
[data-motion="off"] .halo::after,
[data-motion="off"] .scroll-cue::after,
[data-motion="off"] .tile,
[data-motion="off"] .chip.flash { animation: none; }
[data-motion="off"] .marquee-row { flex-wrap: wrap; width: auto; justify-content: center; }
[data-motion="off"] .marquee-row img:nth-child(n + 13) { display: none; }
[data-motion="off"] .vbar i::before { transform: none; transition: none; }
[data-motion="off"] .tile:hover, [data-motion="off"] .lift:hover, [data-motion="off"] .fig-card:hover { transform: none; }

/* ---------------- tablets and phones ---------------- */
@media (max-width: 1199.98px) {
    .nav-links a { padding: .38rem .55rem; font-size: .84rem; }
}
/* below this the nine links no longer fit: they move into the section menu */
@media (max-width: 991.98px) {
    .nav-links { display: none; }
    .topnav { justify-content: space-between; }
    .menu-btn { display: inline-flex; }
    .topnav.is-open .nav-links {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: calc(100% + .45rem);
        right: 0;
        width: min(15rem, 100%);
        margin: 0;
        padding: .45rem;
        gap: .1rem;
        border-radius: 1.1rem;
        background: var(--surface-solid);
        border: 1px solid var(--line);
        backdrop-filter: blur(16px) saturate(140%);
        -webkit-backdrop-filter: blur(16px) saturate(140%);
        box-shadow: var(--nav-shadow);
    }
    .topnav.is-open .nav-links a { padding: .6rem .9rem; font-size: .95rem; border-radius: .8rem; }
}
@media (max-width: 767.98px) {
    .sec { padding: 4.2rem 0; }
    .topnav { padding-left: .8rem; gap: .4rem; }
    .motion-btn .lab { display: none; }
    .wall-grid { grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: .5rem; }
    .wall-grid.decks { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .real-grid { grid-template-columns: 1fr 1fr; gap: .5rem; }
    .eq-row { grid-template-columns: 1fr; }
    .real-row { grid-template-columns: 1fr; gap: .5rem; }
    .real-label span { display: inline; margin: 0 0 0 .5rem; }
}
@media (max-width: 575.98px) {
    .pill { padding: .55rem 1rem; font-size: .88rem; }
    .memory-row { grid-template-columns: 1fr; gap: .35rem; }
    .wall-grid, .wall-grid.decks { grid-template-columns: 1fr 1fr; }
    .real-trio { display: flex; overflow-x: auto; scroll-snap-type: x mandatory; scrollbar-width: none; }
    .real-clip { flex: 0 0 82%; scroll-snap-align: start; }
    .tile-sr { display: none; }
    .lb-foot { flex-wrap: wrap; }
    .ro-tabs { flex-wrap: nowrap; overflow-x: auto; scrollbar-width: none; }
    .ro-tab { flex: none; padding: .5rem .8rem; font-size: .86rem; }
    .wall { max-height: 70vh; }
    .seg button { white-space: nowrap; padding: .32rem .6rem; }
    .eyebrow { font-size: 1.05rem; }
    .hero-brand .logo { height: 2.1rem; }
    .fig-tabs { flex-wrap: nowrap; overflow-x: auto; scrollbar-width: none; }
    .fig-tabs button { flex: none; }
}