/* =============================================================================
   KANMMU · SPATIAL v3  —  “SPECTRAL VECTOR”
   Design system shell for every page using _layouts/space.html.
   Owner: lead.  Do not edit from other agents: put page/HUD styles in
   pages.css / hud.css / viz.css / prose.css.

   Structure
     0  typefaces
     1  tokens
     2  reset + base
     3  world plate, canvas, boot, frame, cursor
     4  track / station / layer / panel (3D projection shell)
     5  type scale
     6  components (buttons, links, chips, rows, stats, tools, towers)
     7  v3 primitives (kicker, numeral, kpi, slab, band, grids, viz)
     8  motion  (station reveal, entrance, reduced motion)
     9  language switching
    10  HUD base (visual styling lives in hud.css)
    11  flat / no-JS document
    12  ambient reading backdrop
    13  responsive
   ========================================================================== */

/* ---------- 0. Typefaces ------------------------------------------------ */
@font-face {
  font-family: 'SP Display';
  src: url('../../fonts/archivo-latin-wdth-normal.woff2') format('woff2');
  font-weight: 100 900;
  font-stretch: 62% 125%;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'SP Mono';
  src: url('../../fonts/jbmono-latin-wght-normal.woff2') format('woff2');
  font-weight: 100 800;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'SP Serif';
  src: url('../../fonts/instrument-serif-latin-400-normal.woff2') format('woff2');
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

/* ---------- 1. Tokens -------------------------------------------------- */
:root {
  /* surfaces */
  --ink-0: #05060a;
  --ink-1: #090b10;
  --ink-2: #10131a;

  /* light */
  --paper: #f7f7f4;
  --paper-2: #c9cdd6;
  --mute: #979dab;
  --dim: #737b8a;

  /* spectral gradient — the only colour on the site */
  --g-violet: #7c5cff;
  --g-cyan: #24d6ea;
  --g-lime: #c6ff4a;
  --g-rose: #ff5c7a;
  --grad: linear-gradient(100deg, var(--g-violet) 0%, var(--g-cyan) 38%, var(--g-lime) 74%, var(--g-rose) 100%);
  --grad-2: linear-gradient(180deg, var(--g-violet), var(--g-cyan) 55%, var(--g-lime));

  /* lines */
  --line-1: rgba(255, 255, 255, .09);
  --line-2: rgba(255, 255, 255, .20);
  --line-3: rgba(255, 255, 255, .42);

  /* type */
  --f-display: 'SP Display', 'Archivo', 'Helvetica Neue', Arial, system-ui, sans-serif;
  --f-mono: 'SP Mono', ui-monospace, 'SF Mono', 'Cascadia Mono', Consolas, monospace;
  --f-serif: 'SP Serif', 'Instrument Serif', 'Times New Roman', serif;
  --f-cjk: 'PingFang SC', 'HarmonyOS Sans SC', 'Source Han Sans SC', 'Noto Sans SC',
           'Microsoft YaHei UI', 'Microsoft YaHei', system-ui, sans-serif;
  --f-body: 'SP Display', 'PingFang SC', 'HarmonyOS Sans SC', 'Source Han Sans SC',
            'Noto Sans SC', 'Microsoft YaHei UI', 'Microsoft YaHei', system-ui, sans-serif;

  /* motion */
  --e-out: cubic-bezier(.16, 1, .3, 1);
  --e-in-out: cubic-bezier(.76, 0, .24, 1);
  --e-snap: cubic-bezier(.2, .9, .1, 1);
  --d-fast: .16s;
  --d-mid: .42s;
  --d-slow: .9s;

  /* rhythm */
  --gut: clamp(20px, 2.4vw, 40px);
  --hud-h: 64px;

  /* runtime */
  --sp-scroll: 0;
  --sp-vel: 0;
  --sp-cursor-lerp: .16;

  /* ---- v2 compatibility aliases ----------------------------------------
     pages.css / prose.css / lab.css still reference the v2 cold-glass tokens.
     Until those files are migrated, map them onto the v3 palette so secondary
     pages never render with undefined colours. */
  --c-void: var(--ink-0);
  --c-ink: var(--ink-1);
  --c-slate: var(--ink-2);
  --c-graphite: #161a22;
  --c-white: var(--paper);
  --c-mist: var(--paper-2);
  --c-steel: var(--mute);
  --c-cyan: var(--g-cyan);
  --c-cyan-2: #4bb9c9;
  --c-cyan-soft: rgba(36, 214, 234, .5);
  --ln-1: var(--line-1);
  --ln-2: var(--line-2);
  --ln-3: var(--line-3);
  --ln-hard: var(--line-3);
  --gl-1: rgba(255, 255, 255, .04);
  --gl-2: rgba(255, 255, 255, .07);
  --gl-3: rgba(255, 255, 255, .11);
  --grad-vent: linear-gradient(180deg, rgba(255, 255, 255, .07), transparent 62%);
  --grad-sheen: linear-gradient(112deg, rgba(255, 255, 255, .08) 0%, transparent 26%, transparent 62%, rgba(36, 214, 234, .06) 100%);
  --grad-cold: linear-gradient(168deg, #0c0f15 0%, #080a0f 46%, var(--ink-0) 100%);
}

/* ---------- 2. Reset + base -------------------------------------------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: auto; /* the camera timeline owns scrolling */
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--ink-0);
  color: var(--paper-2);
}

body.sp-body {
  font-family: var(--f-body);
  font-weight: 400;
  font-size: 17px;
  line-height: 1.62;
  font-synthesis-weight: none;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  min-height: 100%;
  /* the 3D world is near black; the body must not fight it */
  color-scheme: dark;
}

.sp-body ::selection {
  background: var(--g-cyan);
  color: var(--ink-0);
}

.sp-body :where(a) { color: inherit; text-decoration: none; }
.sp-body :where(button) { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
.sp-body :where(img, svg, canvas) { display: block; max-width: 100%; }
.sp-body :where(h1, h2, h3, h4, p, ul, ol, dl, dd, figure) { margin: 0; }
.sp-body :where(ul, ol) { list-style: none; padding: 0; }
.sp-body :where(hr) { border: 0; }

:where(a, button, [tabindex]):focus-visible {
  outline: 1px solid var(--paper);
  outline-offset: 4px;
}

.sp-sr {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.sp-skip {
  position: fixed;
  left: 50%; top: 10px;
  translate: -50% 0;
  z-index: 300;
  padding: 14px 22px;
  font: 700 11px/1 var(--f-mono);
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--ink-0);
  background: var(--paper);
  border-radius: 0;
  transform: translateY(-180%);
  transition: transform .32s var(--e-out);
}
.sp-skip:focus-visible { transform: none; }

/* ---------- 3. World plate / canvas / boot / frame / cursor ------------ */
#sp-gl {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  z-index: 0;
  pointer-events: none;
  touch-action: pan-y;
}

.sp-plate {
  position: fixed;
  inset: 0;
  z-index: 0;
  background:
    radial-gradient(120% 90% at 50% -10%, #0d1018 0%, #07080d 46%, var(--ink-0) 82%),
    var(--ink-0);
}
.sp-plate::after {
  /* a plan grid, only legible at the edges: a coordinate reference, not decoration */
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--line-1) 1px, transparent 1px),
    linear-gradient(to bottom, var(--line-1) 1px, transparent 1px);
  background-size: 120px 120px;
  mask-image: radial-gradient(80% 60% at 50% 45%, transparent 0%, #000 86%);
  opacity: .5;
}

.sp-boot {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: grid;
  place-items: center;
  background: var(--ink-0);
  transition: opacity .65s var(--e-out), visibility .65s;
}
.sp-boot[data-done='true'] { opacity: 0; visibility: hidden; }
.sp-boot__inner { width: min(440px, 62vw); }
.sp-boot__t {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  font: 500 10.5px/1 var(--f-mono);
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--mute);
}
.sp-boot__bar {
  position: relative;
  height: 1px;
  margin-top: 16px;
  background: var(--line-2);
  overflow: hidden;
}
.sp-boot__bar i {
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 0;
  background: var(--grad);
  transition: width .35s var(--e-out);
}

.sp-frame {
  position: fixed;
  inset: 16px;
  z-index: 38;
  pointer-events: none;
}
.sp-frame::before,
.sp-frame::after {
  content: '';
  position: absolute;
  width: 34px; height: 34px;
  border: 0 solid var(--line-2);
}
.sp-frame::before { top: 0; left: 0; border-width: 1px 0 0 1px; }
.sp-frame::after { bottom: 0; right: 0; border-width: 0 1px 1px 0; }

.sp-cursor {
  position: fixed;
  left: 0; top: 0;
  z-index: 120;
  width: 22px; height: 22px;
  margin: -11px 0 0 -11px;
  pointer-events: none;
  opacity: 0;
  transition: opacity .28s var(--e-out), width .22s var(--e-out), height .22s var(--e-out), margin .22s var(--e-out);
  mix-blend-mode: difference;
  will-change: transform;
}
.sp-cursor::before {
  content: '';
  position: absolute;
  inset: 0;
  border: 1px solid rgba(255, 255, 255, .85);
  border-radius: 50%;
  transition: background .2s var(--e-out), transform .2s var(--e-out);
}
.sp-cursor::after {
  content: '';
  position: absolute;
  left: 50%; top: 50%;
  width: 4px; height: 4px;
  margin: -2px 0 0 -2px;
  background: rgba(255, 255, 255, .95);
}
body.sp-has-pointer .sp-cursor { opacity: 1; }
body.sp-cursor-hot .sp-cursor { width: 44px; height: 44px; margin: -22px 0 0 -22px; }
body.sp-cursor-hot .sp-cursor::before { background: rgba(255, 255, 255, .12); }
@media (pointer: coarse) { .sp-cursor { display: none !important; } }

/* ---------- 4. Track / station / layer / panel ------------------------- */
.sp-track {
  position: relative;
  z-index: 2;
}

.sp-station {
  position: relative;
  min-height: 100svh;
  width: 100%;
  pointer-events: none;
}

/* the projected layer of a station (fixed by the runtime) */
.sp-layer {
  position: absolute;
  inset: 0;
  z-index: 3;
  pointer-events: none;
}

/* a projected panel: positioned + matrix3d() by the engine.
   Never put a transform of your own on .sp-panel — the projector writes it
   every frame. Animate children instead. */
.sp-panel {
  position: absolute;
  left: 0;
  top: 0;
  transform-origin: 0 0;
  will-change: transform, opacity;
  pointer-events: auto;
  backface-visibility: hidden;
  contain: layout style;
  opacity: 0;
  transition: opacity .8s var(--e-out);
}
.sp-panel.is-in { opacity: 1; }
.sp-panel--ghost { pointer-events: none; }
.sp-flat .sp-panel { opacity: 1 !important; }

/* dark scrim behind panels that carry dense data — reads as a smoked plate,
   never as a UI card: one hairline at the top, no radius, no blur.
   The scrim is an inset ::before so the panel box stays exactly the text box:
   the authored data-sp-pos coordinates remain true. */
.sp-panel[data-sp-slab]::before {
  content: '';
  position: absolute;
  inset: -22px -26px -24px;
  z-index: -1;
  background: linear-gradient(180deg, rgba(8, 10, 15, .58) 0%, rgba(6, 8, 12, .72) 60%, rgba(5, 7, 10, .80) 100%);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .12);
  pointer-events: none;
}
.sp-panel[data-sp-slab='ink']::before {
  background: linear-gradient(180deg, rgba(6, 8, 12, .82) 0%, rgba(4, 6, 9, .90) 100%);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .08);
}
.sp-panel[data-sp-slab] > .sp-label:first-child { margin-bottom: 14px; }

/* legacy glass (other pages) — kept functional, restyled hard */
.sp-glass {
  position: absolute;
  inset: 0;
  z-index: -1;
  background: rgba(10, 12, 18, .55);
  border: 1px solid var(--line-1);
  pointer-events: none;
  overflow: hidden;
}
.sp-glass::before,
.sp-glass::after { content: none; }

/* ---------- 5. Type scale ---------------------------------------------- */
.sp-display {
  font-family: var(--f-display);
  font-weight: 800;
  font-stretch: 112%;
  font-size: clamp(64px, 8.2vw, 132px);
  line-height: .86;
  letter-spacing: -.045em;
  text-transform: uppercase;
  color: var(--paper);
  font-feature-settings: 'kern' 1, 'liga' 1;
  text-wrap: balance;
}
.sp-display .sp-line { display: block; }
.sp-display [data-zh],
.sp-display .sp-cjk {
  font-family: var(--f-cjk);
  font-weight: 700;
  font-stretch: 100%;
  letter-spacing: -.03em;
  text-transform: none;
}
.sp-display__sub {
  margin-top: 22px;
  font-family: var(--f-display);
  font-weight: 500;
  font-size: clamp(16px, 1.35vw, 21px);
  line-height: 1.35;
  letter-spacing: .03em;
  color: var(--paper-2);
  text-transform: uppercase;
}
.sp-display__sub [data-zh] { font-family: var(--f-cjk); text-transform: none; letter-spacing: .01em; }

.sp-h2 {
  font-family: var(--f-display);
  font-weight: 700;
  font-stretch: 108%;
  font-size: clamp(44px, 5.2vw, 88px);
  line-height: .92;
  letter-spacing: -.04em;
  color: var(--paper);
  text-transform: uppercase;
  text-wrap: balance;
}
.sp-h2 [data-zh] {
  font-family: var(--f-cjk);
  font-weight: 700;
  letter-spacing: -.02em;
  text-transform: none;
}

.sp-h3 {
  font-family: var(--f-display);
  font-weight: 600;
  font-stretch: 104%;
  font-size: clamp(24px, 2.05vw, 34px);
  line-height: 1.08;
  letter-spacing: -.025em;
  color: var(--paper);
}
.sp-h3 [data-zh] { font-family: var(--f-cjk); font-weight: 600; letter-spacing: 0; }

.sp-lede {
  font-family: var(--f-cjk);
  font-size: clamp(21px, 1.6vw, 28px);
  line-height: 1.45;
  letter-spacing: -.005em;
  color: var(--paper-2);
  max-width: 34em;
  text-wrap: pretty;
}
.sp-lede--cjk { font-size: clamp(19px, 1.4vw, 23px); line-height: 1.62; }

.sp-xl {
  font-family: var(--f-cjk);
  font-size: clamp(24px, 1.95vw, 32px);
  line-height: 1.38;
  letter-spacing: -.012em;
  color: var(--paper);
  text-wrap: pretty;
}

.sp-body-copy {
  font-family: var(--f-cjk);
  font-size: 21px;
  line-height: 1.62;
  letter-spacing: .004em;
  color: var(--paper-2);
  max-width: 38em;
  text-wrap: pretty;
}
.sp-body-copy + .sp-body-copy { margin-top: 14px; }
.sp-body-copy strong { color: var(--paper); font-weight: 600; }
.sp-body-copy a { color: var(--paper); border-bottom: 1px solid var(--line-2); }

.sp-copy-zh,
.sp-copy-en { display: block; }
.sp-copy-en {
  font-family: var(--f-display);
  font-size: 19px;
  line-height: 1.55;
  letter-spacing: -.005em;
}

/* mono label system — the instrument panel voice */
.sp-label,
.sp-eyebrow,
.sp-kicker,
.sp-caps {
  font-family: var(--f-mono);
  font-weight: 500;
  font-size: 12px;
  line-height: 1.2;
  letter-spacing: .17em;
  text-transform: uppercase;
  color: var(--mute);
}

.sp-eyebrow {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  white-space: nowrap;
}
.sp-eyebrow i {
  display: block;
  width: 7px; height: 7px;
  background: var(--g-cyan);
  transform: rotate(45deg);
}
.sp-eyebrow s {
  display: block;
  width: 40px;
  height: 1px;
  background: var(--line-2);
  text-decoration: none;
}

.sp-kicker {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--paper-2);
}
.sp-kicker i {
  width: 22px;
  height: 2px;
  background: var(--grad);
}
.sp-kicker span {
  margin-left: auto;
  color: var(--mute);
  letter-spacing: .14em;
}

.sp-meta {
  font-family: var(--f-mono);
  font-size: 13.5px;
  line-height: 1.85;
  letter-spacing: .06em;
  color: var(--mute);
}
.sp-meta b { color: var(--paper); font-weight: 500; }
.sp-meta + .sp-meta { margin-top: 6px; }

.sp-note-tiny {
  font-family: var(--f-cjk);
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--mute);
}

.sp-num {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: -.02em;
  color: var(--paper);
}

.sp-accent {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.sp-quote {
  font-family: var(--f-serif);
  font-weight: 400;
  font-style: italic;
  font-size: clamp(26px, 2.6vw, 40px);
  line-height: 1.22;
  letter-spacing: -.01em;
  color: var(--paper);
  text-wrap: pretty;
}
.sp-quote [data-zh] { font-family: var(--f-cjk); font-style: normal; font-weight: 500; font-size: .72em; letter-spacing: 0; }

.sp-nowrap { white-space: nowrap; }

/* ---------- 6. Components ---------------------------------------------- */
.sp-rule {
  display: block;
  height: 1px;
  background: var(--line-2);
  border: 0;
  margin: 0;
}
.sp-rule::before,
.sp-rule::after { content: none; }

.sp-hair {
  display: block;
  height: 1px;
  background: var(--line-1);
  border: 0;
}

/* buttons: a hard frame that inverts on hover, with a gradient underline that
   draws itself. No radius, no shadow. */
.sp-btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  gap: 22px;
  min-height: 54px;
  padding: 0 22px;
  border: 1px solid var(--line-2);
  font-family: var(--f-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--paper);
  background: rgba(10, 12, 18, .45);
  overflow: hidden;
  transition: color .24s var(--e-out), border-color .24s var(--e-out), background .24s var(--e-out);
}
.sp-btn .sp-arrow { color: inherit; }
.sp-btn svg {
  width: 15px; height: 15px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.4;
  transition: transform .32s var(--e-out);
}
.sp-btn::after {
  content: '';
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 2px;
  background: var(--grad);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform .42s var(--e-out);
}
.sp-btn:hover,
.sp-btn:focus-visible {
  color: var(--ink-0);
  background: var(--paper);
  border-color: var(--paper);
}
.sp-btn:hover svg { transform: translateX(5px); }
.sp-btn:hover::after { transform: scaleX(1); }
.sp-btn--solid {
  color: var(--ink-0);
  background: var(--paper);
  border-color: var(--paper);
}
.sp-btn--solid:hover { background: transparent; color: var(--paper); }

.sp-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--f-mono);
  font-size: 13px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--paper);
  background-image: linear-gradient(var(--paper), var(--paper));
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 100% 1px;
  padding-bottom: 4px;
  transition: background-size .34s var(--e-out), color .2s;
}
.sp-link svg {
  width: 13px; height: 13px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.5;
  transition: transform .3s var(--e-out);
}
.sp-link:hover { background-size: 0 1px; }
.sp-link:hover svg { transform: translate(2px, -2px); }

.sp-chip {
  display: inline-flex;
  align-items: center;
  padding: 7px 11px;
  border: 1px solid var(--line-1);
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--paper-2);
  white-space: nowrap;
  transition: border-color .2s, color .2s, background .2s;
}
.sp-chip:hover { border-color: var(--paper); color: var(--ink-0); background: var(--paper); }

/* row lists: publications, notes, research directions, tools */
.sp-pub,
.sp-note,
.sp-item {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: baseline;
  gap: 18px;
  padding: 16px 0;
  border-top: 1px solid var(--line-1);
  transition: background .28s var(--e-out), border-color .28s var(--e-out), padding .28s var(--e-out);
}
.sp-pub:hover,
.sp-note:hover,
.sp-item:hover {
  border-top-color: var(--line-3);
  background: linear-gradient(90deg, rgba(255, 255, 255, .045), transparent 76%);
  padding-left: 10px;
  padding-right: 10px;
}
.sp-pub { grid-template-columns: 62px 1fr; }
.sp-pub__yr {
  font-family: var(--f-mono);
  font-size: 14px;
  letter-spacing: .04em;
  color: var(--mute);
  font-variant-numeric: tabular-nums;
}
.sp-pub h3 {
  font-family: var(--f-display);
  font-size: clamp(20px, 1.35vw, 24px);
  font-weight: 500;
  line-height: 1.28;
  letter-spacing: -.012em;
  color: var(--paper);
  text-wrap: pretty;
}
.sp-pub p {
  margin-top: 6px;
  font-family: var(--f-mono);
  font-size: 12px;
  line-height: 1.5;
  letter-spacing: .05em;
  color: var(--mute);
  text-transform: uppercase;
}

.sp-note { grid-template-columns: 1fr auto; align-items: center; }
.sp-note > span:first-child {
  display: flex;
  gap: 14px;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--mute);
  white-space: nowrap;
}
.sp-note h3 {
  font-family: var(--f-cjk);
  font-size: clamp(19px, 1.3vw, 23px);
  font-weight: 500;
  line-height: 1.4;
  color: var(--paper);
}
.sp-note:hover h3 { color: var(--paper); }

.sp-tool {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 16px;
  padding: 18px 0;
  border-top: 1px solid var(--line-1);
}
.sp-tool__mark {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--paper);
  border: 1px solid var(--line-2);
  padding: 4px 6px;
  min-width: 30px;
  text-align: center;
}
.sp-tool h3 {
  font-family: var(--f-display);
  font-size: clamp(18px, 1.2vw, 21px);
  font-weight: 600;
  letter-spacing: -.01em;
  color: var(--paper);
}
.sp-tool p {
  margin-top: 4px;
  font-family: var(--f-cjk);
  font-size: 16.5px;
  line-height: 1.55;
  color: var(--paper-2);
}
.sp-tool__tech {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--mute);
  text-transform: uppercase;
}

/* research towers (accordion rows) */
.sp-tower {
  display: grid;
  grid-template-columns: 56px 1fr auto;
  align-items: center;
  gap: 16px;
  width: 100%;
  text-align: left;
  padding: 18px 0;
  border-top: 1px solid var(--line-1);
  transition: background .28s, padding .28s, border-color .28s;
}
.sp-tower:last-child { border-bottom: 1px solid var(--line-1); }
.sp-tower:hover { background: rgba(255, 255, 255, .03); padding-left: 10px; padding-right: 10px; }
.sp-tower__no {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--mute);
  font-variant-numeric: tabular-nums;
}
.sp-tower__body h3 {
  font-family: var(--f-cjk);
  font-size: clamp(23px, 1.65vw, 30px);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -.015em;
  color: var(--paper-2);
  transition: color .24s;
}
.sp-tower__body h3 [data-zh] { font-family: var(--f-cjk); }
.sp-tower__body p {
  margin-top: 6px;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--mute);
}
.sp-tower__sig {
  position: relative;
  width: 26px;
  height: 26px;
  border: 1px solid var(--line-2);
}
.sp-tower__sig::before,
.sp-tower__sig::after {
  content: '';
  position: absolute;
  background: var(--paper);
  transition: transform .3s var(--e-out), opacity .3s;
}
.sp-tower__sig::before { left: 50%; top: 6px; bottom: 6px; width: 1px; transform: translateX(-.5px); }
.sp-tower__sig::after { top: 50%; left: 6px; right: 6px; height: 1px; transform: translateY(-.5px); }
.sp-tower[aria-expanded='true'] .sp-tower__body h3 { color: var(--paper); }
.sp-tower[aria-expanded='true'] .sp-tower__sig { border-color: var(--paper); }
.sp-tower[aria-expanded='true'] .sp-tower__sig::after { transform: translateY(-.5px) scaleX(0); }

/* stats table */
.sp-stats { display: grid; gap: 0; }
.sp-stats__row {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: baseline;
  gap: 16px;
  padding: 12px 0;
  border-top: 1px solid var(--line-1);
}
.sp-stats__row:last-child { border-bottom: 1px solid var(--line-1); }
.sp-stats__row b {
  font-family: var(--f-mono);
  font-size: clamp(30px, 2.4vw, 40px);
  font-weight: 400;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}
.sp-stats__row span { font-family: var(--f-cjk); font-size: 16px; color: var(--paper-2); }
.sp-stats__row em {
  font-family: var(--f-mono);
  font-style: normal;
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--mute);
  text-transform: uppercase;
}

/* ---------- 7. v3 primitives ------------------------------------------- */
.sp-numeral {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 10px;
  padding-bottom: 4px;
}
.sp-ghost {
  display: block;
  font-family: var(--f-display);
  font-weight: 800;
  font-stretch: 118%;
  font-size: clamp(110px, 14vw, 230px);
  line-height: .74;
  letter-spacing: -.06em;
  color: transparent;
  -webkit-text-stroke: 1px var(--line-3);
  font-variant-numeric: tabular-nums;
}
.sp-numeral > .sp-caps { color: var(--mute); }

.sp-kpi {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  grid-template-areas: 'v l' 'v s';
  column-gap: 16px;
  align-items: baseline;
  padding: 14px 0;
  border-top: 1px solid var(--line-1);
  overflow: hidden;
}
.sp-kpi:last-child { border-bottom: 1px solid var(--line-1); }
.sp-kpi__v {
  grid-area: v;
  font-family: var(--f-mono);
  font-weight: 300;
  font-size: clamp(48px, 4.4vw, 68px);
  line-height: .9;
  letter-spacing: -.05em;
  color: var(--paper);
  font-variant-numeric: tabular-nums;
}
.sp-kpi__l {
  grid-area: l;
  align-self: end;
  font-family: var(--f-cjk);
  font-size: 16px;
  color: var(--paper-2);
}
.sp-kpi__src {
  grid-area: s;
  font-family: var(--f-mono);
  font-style: normal;
  font-size: 12px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--dim);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.sp-slab {
  position: relative;
  border: 1px solid var(--line-1);
  padding: 22px 24px;
  background: rgba(8, 10, 15, .40);
}
.sp-slab--fill { background: rgba(6, 8, 12, .82); }

.sp-band {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: clamp(20px, 3vw, 56px);
  padding-top: 18px;
  border-top: 1px solid var(--line-2);
}
.sp-band > * { min-width: 0; }

.sp-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--gut);
}
.sp-grid2 { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1px; background: var(--line-1); }
.sp-grid3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1px; background: var(--line-1); }
.sp-grid4 { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 1px; background: var(--line-1); }
.sp-grid2 > *,
.sp-grid3 > *,
.sp-grid2 > *,
.sp-grid3 > *,
.sp-grid4 > * {
  background: rgba(6, 8, 12, .58);
  padding: 16px 18px;
  min-width: 0;
}
/* inside a hard-line grid the tile is the card: drop the row chrome */
.sp-grid2 .sp-tool,
.sp-grid3 .sp-tool,
.sp-grid4 .sp-tool { border-top: 0; padding: 0; display: block; }
.sp-grid2 .sp-tool__mark,
.sp-grid3 .sp-tool__mark,
.sp-grid4 .sp-tool__mark {
  display: inline-grid;
  place-items: center;
  min-width: 34px;
  height: 26px;
  margin-bottom: 14px;
}
.sp-grid2 .sp-tool h3,
.sp-grid3 .sp-tool h3,
.sp-grid4 .sp-tool h3 { margin-bottom: 8px; font-size: 20px; }
.sp-grid2 .sp-tool p,
.sp-grid3 .sp-tool p,
.sp-grid4 .sp-tool p {
  font-size: 14.5px;
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 4;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.sp-grid2 .sp-tool__tech,
.sp-grid3 .sp-tool__tech,
.sp-grid4 .sp-tool__tech { display: block; margin-top: 12px; }

.sp-rowline {
  display: grid;
  grid-template-columns: 46px 1fr 26px;
  align-items: center;
  gap: 16px;
  padding: 15px 0;
  border-top: 1px solid var(--line-1);
  transition: padding .28s var(--e-out), background .28s var(--e-out), border-color .28s var(--e-out);
}
.sp-rowline:last-child { border-bottom: 1px solid var(--line-1); }
.sp-rowline:hover {
  border-color: var(--line-3);
  background: linear-gradient(90deg, rgba(255, 255, 255, .05), transparent 80%);
  padding-left: 10px;
  padding-right: 10px;
}
.sp-rowline__no {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--mute);
  font-variant-numeric: tabular-nums;
}
.sp-rowline__body { display: flex; flex-direction: column; gap: 5px; }
.sp-rowline__body b {
  font-family: var(--f-cjk);
  font-size: clamp(20px, 1.35vw, 24px);
  font-weight: 500;
  line-height: 1.35;
  color: var(--paper);
}
.sp-rowline__body em {
  font-family: var(--f-mono);
  font-style: normal;
  font-size: 11px;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--mute);
}
.sp-arrow {
  font-family: var(--f-mono);
  font-size: 16px;
  color: var(--mute);
  transition: transform .3s var(--e-out), color .2s;
}
.sp-rowline:hover .sp-arrow { transform: translate(3px, -3px); color: var(--paper); }

.sp-figure { margin: 0; }
.sp-figure__cap {
  margin-top: 8px;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--dim);
}

/* small utility rhythm (kept from v2, used everywhere) */
.sp-row { display: flex; align-items: center; }
.sp-col { display: flex; flex-direction: column; }
.sp-wrap { flex-wrap: wrap; }
.sp-gap-8 { gap: 8px; }
.sp-gap-14 { gap: 14px; }
.sp-gap-22 { gap: 22px; }
.sp-mt-16 { margin-top: 16px; }
.sp-mt-26 { margin-top: 26px; }

/* ---------- 8. Motion -------------------------------------------------- */
@keyframes sp-rise {
  from { opacity: 0; transform: translate3d(0, 22px, 0); }
  to { opacity: 1; transform: translate3d(0, 0, 0); }
}
@keyframes sp-rule-in {
  from { transform: scaleX(0); }
  to { transform: scaleX(1); }
}
@keyframes sp-sweep {
  from { background-position: -40% 0; }
  to { background-position: 140% 0; }
}

.sp-panel.is-in > :not(.sp-glass) {
  animation: sp-rise .92s var(--e-out) both;
  animation-delay: calc(var(--sp-o, 0) * 60ms);
}
.sp-panel.is-in > :nth-child(2) { --sp-o: 1; }
.sp-panel.is-in > :nth-child(3) { --sp-o: 2; }
.sp-panel.is-in > :nth-child(4) { --sp-o: 3; }
.sp-panel.is-in > :nth-child(5) { --sp-o: 4; }
.sp-panel.is-in > :nth-child(6) { --sp-o: 5; }
.sp-panel.is-in > :nth-child(7) { --sp-o: 6; }

.sp-station.is-live .sp-rule { transform-origin: 0 50%; animation: sp-rule-in 1.1s var(--e-out) both; }

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .sp-panel.is-in > :not(.sp-glass) { animation: none; }
}

/* ---------- 9. Language switching -------------------------------------- */
html[data-lang='zh'] [data-en] { display: none !important; }
html[data-lang='en'] [data-zh] { display: none !important; }
html[data-lang='zh'] .sp-copy-en { display: none !important; }
html[data-lang='en'] .sp-copy-zh { display: none !important; }

.sp-lang {
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--line-2);
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: .1em;
}
.sp-lang button {
  min-width: 44px;
  height: 34px;
  padding: 0 10px;
  color: var(--mute);
  transition: background .2s, color .2s;
}
.sp-lang button[aria-pressed='true'] { background: var(--paper); color: var(--ink-0); }
.sp-lang button:hover { color: var(--paper); }
.sp-lang button[aria-pressed='true']:hover { color: var(--ink-0); }

/* ---------- 10. HUD base (visual language: hud.css) -------------------- */
/* Low specificity on purpose: hud.css owns the look, these keep the shell
   usable while it loads or if it fails. */
:where(.sp-topbar) {
  position: fixed;
  left: 0; right: 0; top: 0;
  z-index: 40;
  height: var(--hud-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 0 var(--gut);
}
:where(.sp-brand) { display: inline-flex; align-items: center; gap: 12px; }
:where(.sp-brand__mark) {
  display: grid;
  place-items: center;
  width: 30px; height: 30px;
  border: 1px solid var(--line-2);
  font-family: var(--f-mono);
  font-size: 13px;
  color: var(--paper);
}
:where(.sp-brand__name) {
  display: block;
  font-family: var(--f-display);
  font-weight: 600;
  font-size: 15px;
  letter-spacing: .01em;
  color: var(--paper);
}
:where(.sp-brand__sub) {
  display: block;
  font-family: var(--f-mono);
  font-size: 9px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--mute);
}
:where(.sp-menu) { display: flex; align-items: center; gap: 4px; }
:where(.sp-menu a) {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  height: 40px;
  padding: 0 12px;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--mute);
  transition: color .2s;
}
:where(.sp-menu a) i { font-style: normal; font-size: 9px; color: var(--dim); }
:where(.sp-menu a):hover,
:where(.sp-menu a)[aria-current='page'] { color: var(--paper); }
:where(.sp-rail) {
  position: fixed;
  left: var(--gut);
  top: 50%;
  translate: 0 -50%;
  z-index: 40;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
:where(.sp-readout) { position: fixed; right: var(--gut); bottom: 26px; z-index: 40; }
:where(.sp-status) { position: fixed; left: var(--gut); bottom: 24px; z-index: 40; }
:where(.sp-hint) { position: fixed; left: 50%; bottom: 26px; translate: -50% 0; z-index: 40; }
:where(.sp-map-wrap) { position: fixed; right: var(--gut); bottom: 92px; z-index: 40; }

/* ---------- 11. Flat / no-JS document ---------------------------------- */
.sp-flat .sp-track {
  max-width: 1080px;
  margin: 0 auto;
  padding: clamp(88px, 12vh, 140px) var(--gut) 96px;
}
.sp-flat .sp-station {
  min-height: 0;
  padding: clamp(40px, 6vw, 84px) 0;
  border-top: 1px solid var(--line-1);
}
.sp-flat .sp-station:first-child { border-top: 0; padding-top: 0; }
.sp-flat .sp-layer {
  position: static;
  inset: auto;
  display: block;
  pointer-events: auto;
}
.sp-flat .sp-panel,
.sp-flat .sp-panel[data-sp-slab] {
  position: static !important;
  width: auto !important;
  max-width: none;
  padding: 0;
  margin: 0 0 clamp(30px, 4vw, 52px);
  border: 0;
  background: none;
  box-shadow: none;
  transform: none !important;
  contain: none;
  opacity: 1 !important;
}
.sp-flat .sp-panel:last-child { margin-bottom: 0; }
.sp-flat .sp-panel[data-sp-slab]::before { content: none; }
.sp-flat .sp-glass { display: none; }
.sp-flat .sp-numeral { display: none; }
.sp-flat .sp-display { font-size: clamp(44px, 8.6vw, 96px); }
.sp-flat .sp-h2 { font-size: clamp(34px, 6vw, 64px); }
.sp-flat .sp-lede { font-size: clamp(18px, 2.2vw, 23px); max-width: none; }
.sp-flat .sp-body-copy { font-size: 18px; max-width: none; }
.sp-flat .sp-ghost { -webkit-text-stroke-color: var(--line-2); }

.sp-flat .sp-rail,
.sp-flat .sp-readout,
.sp-flat .sp-status,
.sp-flat .sp-hint,
.sp-flat .sp-cursor,
.sp-flat #sp-gl,
.sp-flat .sp-frame,
.sp-flat .sp-map-wrap { display: none !important; }
.sp-flat .sp-topbar {
  position: sticky;
  top: 0;
  background: rgba(5, 6, 10, .94);
  border-bottom: 1px solid var(--line-1);
}

/* ---------- 12. Ambient reading backdrop ------------------------------- */
.sp-flat.sp-ambient #sp-gl { display: block; opacity: .82; }
.sp-flat.sp-ambient .sp-track { max-width: 900px; }
.sp-flat.sp-ambient .sp-station:first-child .sp-layer { padding-top: clamp(20px, 6vh, 60px); }
.sp-flat.sp-ambient .sp-topbar { background: rgba(5, 6, 10, .88); }
.sp-flat.sp-ambient .sp-glass { display: none; }

/* ---------- 13. Responsive -------------------------------------------- */
@media (max-width: 1200px) {
  .sp-menu { gap: 0; }
  .sp-menu a { padding: 0 8px; letter-spacing: .06em; }
}

@media (max-width: 900px) {
  :root { --gut: 20px; --hud-h: 56px; }
  body.sp-body { font-size: 17px; }
  .sp-flat .sp-track { padding-top: 76px; }
  .sp-flat .sp-display { font-size: clamp(40px, 10vw, 82px); }
  .sp-flat .sp-body-copy { font-size: 17.5px; }
  .sp-flat .sp-pub { grid-template-columns: 48px 1fr; gap: 12px; }
  .sp-flat .sp-note { grid-template-columns: 1fr; gap: 4px; }
  .sp-flat .sp-note > span:first-child { order: 2; }
  .sp-chip { font-size: 11px; padding: 6px 9px; }
  .sp-grid2,
  .sp-grid3,
  .sp-grid4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .sp-rule { margin-inline: 0; }
  .sp-quote { font-size: clamp(22px, 5.4vw, 30px); }
  .sp-kpi__v { font-size: clamp(38px, 8vw, 52px); }
  .sp-ghost { font-size: clamp(88px, 22vw, 150px); }
}

@media (max-width: 560px) {
  .sp-grid2,
  .sp-grid3,
  .sp-grid4 { grid-template-columns: 1fr; }
  .sp-flat .sp-display { font-size: clamp(36px, 11.5vw, 64px); }
  .sp-flat .sp-h2 { font-size: clamp(28px, 9vw, 44px); }
  .sp-pub h3 { font-size: 18px; }
  .sp-rowline { grid-template-columns: 34px 1fr 20px; gap: 10px; }
  .sp-kicker span { display: none; }
}

/* print: the whole site is a document again */
@media print {
  #sp-gl, .sp-plate, .sp-boot, .sp-frame, .sp-cursor, .sp-topbar,
  .sp-rail, .sp-readout, .sp-status, .sp-hint, .sp-map-wrap { display: none !important; }
  html, body { background: #fff; color: #111; }
  .sp-flat .sp-panel { break-inside: avoid; }
}

/* ---------- 14. v3.1 corrections (lead) --------------------------------- */
/* KPI figures inside a 2/3/4-up grid become tiles: number on top, label and
   source under it. Prevents labels breaking one CJK character per line. */
.sp-grid2 .sp-kpi,
.sp-grid3 .sp-kpi,
.sp-grid4 .sp-kpi {
  grid-template-columns: minmax(0, 1fr);
  grid-template-areas: 'v' 'l' 's';
  align-items: start;
  padding: 16px 0 14px;
}
.sp-grid2 .sp-kpi__v,
.sp-grid3 .sp-kpi__v,
.sp-grid4 .sp-kpi__v { font-size: clamp(36px, 3.1vw, 50px); line-height: .92; }
.sp-grid2 .sp-kpi__l,
.sp-grid3 .sp-kpi__l,
.sp-grid4 .sp-kpi__l { align-self: start; margin-top: 8px; font-size: 14px; }
.sp-grid2 .sp-kpi__src,
.sp-grid3 .sp-kpi__src,
.sp-grid4 .sp-kpi__src { margin-top: 3px; }
.sp-kpi__l {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 100%;
}
/* charts must never inherit a phantom min-width from their flex parents */
.sp-viz { position: relative; display: block; width: 100%; margin: 0; }
.sp-viz canvas { display: block; width: 100% !important; height: auto !important; }

/* ---------- 15. definition lists + panel rhythm (lead, v3.1) ------------ */
/* Fact sheets read as a ledger: label column, value column, hairline per row. */
.sp-panel dl { display: grid; gap: 0; margin: 0; }
.sp-panel dl > div {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 4px 16px;
  align-items: baseline;
  padding: 11px 0;
  border-top: 1px solid var(--line-1);
}
.sp-panel dl > div:last-child { border-bottom: 1px solid var(--line-1); }
.sp-panel dt {
  font-family: var(--f-mono);
  font-size: 12px;
  line-height: 1.4;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--mute);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.sp-panel dd {
  min-width: 0;
  font-family: var(--f-cjk);
  font-size: 17px;
  line-height: 1.5;
  color: var(--paper-2);
}
.sp-panel dd a { color: var(--paper); }

/* breathing room after a button row */
.sp-row + .sp-meta { margin-top: 18px; }
.sp-row + .sp-meta.sp-mt-26 { margin-top: 26px; }

@media (max-width: 900px) {
  .sp-panel dl > div { grid-template-columns: 78px minmax(0, 1fr); gap: 2px 12px; }
  .sp-panel dd { font-size: 15.5px; }
}

/* ---------- 16. entrance choreography (lead, v3.2) ---------------------- */
/* The hero is cut in with a hard mask, not faded: the page assembles itself. */
@keyframes sp-cut-in {
  from { clip-path: inset(0 0 106% 0); }
  to { clip-path: inset(0 0 0 0); }
}
@keyframes sp-tick {
  from { transform: scaleX(0); }
  to { transform: scaleX(1); }
}
.sp-panel.is-in .sp-display,
.sp-panel.is-in .sp-h2 {
  animation: sp-cut-in 1.05s var(--e-out) both;
}
.sp-panel.is-in .sp-ghost {
  animation: sp-cut-in 1.25s var(--e-out) both;
}
.sp-panel.is-in .sp-display { animation-delay: .05s; }
.sp-panel.is-in .sp-kicker i {
  transform-origin: 0 50%;
  animation: sp-tick .9s var(--e-out) both;
  animation-delay: .12s;
}
.sp-station.is-live .sp-kicker i { animation: sp-tick .9s var(--e-out) both; }

/* thin instrument scrollbar (the page is a viewport, not a document) */
html { scrollbar-width: thin; scrollbar-color: rgba(255, 255, 255, .22) var(--ink-0); }
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--ink-0); }
::-webkit-scrollbar-thumb { background: rgba(255, 255, 255, .18); }
::-webkit-scrollbar-thumb:hover { background: rgba(255, 255, 255, .32); }

/* long-form text inside a panel: keep the measure readable */
.sp-panel .sp-body-copy + .sp-h3,
.sp-panel .sp-body-copy + .sp-body-copy { margin-top: 16px; }
.sp-panel .sp-h3 + .sp-body-copy { margin-top: 10px; }
.sp-panel .sp-lede + .sp-meta { margin-top: 18px; }

/* ---------- 17. type floor sweep (lead, v3.2) --------------------------- */
/* Nothing that carries reading information is below 12px. */
.sp-rowline__body em,
.sp-stats__row em,
.sp-pub p,
.sp-tool__tech,
.sp-kicker,
.sp-label,
.sp-eyebrow,
.sp-caps,
.sp-figure__cap { font-size: max(12px, 0.75rem); }
.sp-meta { font-size: 13px; }

/* ---------- 18. label scale (lead, v3.3) -------------------------------- */
/* Instrument labels are part of the reading experience: 12.5–13px, never less. */
.sp-label,
.sp-eyebrow,
.sp-caps { font-size: 12.5px; }
.sp-kicker { font-size: 13px; }
.sp-kpi__src { font-size: 12px; color: var(--mute); }
.sp-tool__tech,
.sp-rowline__body em,
.sp-stats__row em { font-size: 12.5px; }
.sp-pub p { font-size: 12.5px; }
.sp-note-tiny { font-size: 14px; }
.sp-figure__cap { font-size: 12px; color: var(--mute); }

/* ---------- 19. automatic data scrims (lead, v3.3) ---------------------- */
/* Slots that carry dense data always get the smoked plate, even if the author
   forgot data-sp-slab: the 3D world must never sit behind white numerals. */
.sp-panel[data-sp-slot="kpi"]::before,
.sp-panel[data-sp-slot="facts"]::before,
.sp-panel[data-sp-slot="viz"]::before,
.sp-panel[data-sp-slot="detail"]::before,
.sp-panel[data-sp-slot="grid"]::before,
.sp-panel[data-sp-slot="list"]::before {
  content: '';
  position: absolute;
  inset: -22px -26px -24px;
  z-index: -1;
  background: linear-gradient(180deg, rgba(7, 9, 13, .84) 0%, rgba(5, 7, 10, .90) 100%);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .10);
  pointer-events: none;
}
/* lighter for wide lists: they have room around the text */
.sp-panel[data-sp-slot="list"]::before {
  background: linear-gradient(180deg, rgba(7, 9, 13, .72) 0%, rgba(5, 7, 10, .82) 100%);
}
.sp-flat .sp-panel[data-sp-slot]::before { content: none; }

/* ---------- 20. flat-mode layout guard (lead, v3.3) --------------------- */
/* pages.css paints the flat `.sp-layer` as a grid for the long-form pages; on
   the home page that grid sizes tracks to the longest unbreakable token (a DOI)
   and blows the 380 px mobile column out by ~140 px. The home flat layout is a
   document, not a grid. */
html.sp-flat body[data-sp-page='home'] .sp-layer {
  display: block !important;
  position: static !important;
}
html.sp-flat body[data-sp-page='home'] .sp-panel {
  width: auto !important;
  max-width: 100%;
}
/* long identifiers (DOI, ORCID, mail) may break instead of overflowing */
.sp-flat .sp-pub p,
.sp-flat .sp-meta,
.sp-flat .sp-note-tiny,
.sp-flat .sp-panel dd,
.sp-flat .sp-link { overflow-wrap: anywhere; }

/* ---------- 21. mobile type scale (lead, v3.3) -------------------------- */
@media (max-width: 900px) {
  .sp-flat .sp-display { font-size: clamp(52px, 13.2vw, 96px); }
  .sp-flat .sp-display__sub { font-size: 17px; margin-top: 16px; }
  .sp-flat .sp-body-copy { font-size: 18.5px; line-height: 1.7; }
  .sp-flat .sp-lede { font-size: 19px; line-height: 1.6; }
  .sp-flat .sp-xl { font-size: 21px; }
  .sp-flat .sp-h2 { font-size: clamp(34px, 9vw, 56px); }
  .sp-flat .sp-h3 { font-size: 24px; }
  .sp-flat .sp-pub h3 { font-size: 19px; }
  .sp-flat .sp-quote { font-size: 24px; }
  .sp-flat .sp-kpi__v { font-size: 46px; }
  .sp-flat .sp-kpi__l { font-size: 16px; }
  .sp-flat .sp-panel { margin-bottom: 40px; }
  .sp-flat .sp-display__sub + .sp-lede { margin-top: 18px; }
}
@media (max-width: 560px) {
  .sp-flat .sp-display { font-size: clamp(46px, 14.5vw, 72px); }
  .sp-flat .sp-body-copy { font-size: 18px; }
}

/* ---------- 22. a11y + size floors (lead, v3.3) ------------------------- */
/* The skip link must be visible the moment it is focused, whatever focused it. */
.sp-skip:focus,
.sp-skip:focus-visible {
  transform: translateY(0) !important;
  visibility: visible !important;
  opacity: 1;
}
.sp-caps { font-size: 13px; }
.sp-chip { font-size: 12.5px; }
.sp-tower__body p { font-size: 12.5px; }
@media (max-width: 900px) {
  .sp-flat .sp-display__sub { font-size: 17px !important; }
  .sp-chip { font-size: 12px; }
}
/* rail hit areas: 24 px of visual ink, 44 px of tappable height */
.sp-rail__btn { min-height: 40px; }