/* Research library pages (built by tools/research/build.mjs). Builds on styles.css tokens. */

/* ---- topic tabs (one link per page) ---- */
.rs-nav {
  position: sticky; top: var(--topbar-h, 64px); z-index: 40;
  background: rgba(var(--bg-rgb), 0.86);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--hair);
}
.rs-nav-in {
  display: flex; align-items: center; gap: 6px;
  max-width: 1380px; margin: 0 auto; padding: 10px var(--gutter);
  overflow-x: auto; scrollbar-width: none; scroll-snap-type: x proximity;
}
.rs-nav-in::-webkit-scrollbar { display: none; }
.rs-nav-group {
  flex: none; font: 500 10px var(--mono); letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--dim); padding: 0 4px 0 14px; border-left: 1px solid var(--faint); margin-left: 6px; white-space: nowrap;
}
.rs-nav-a, .rs-nav-home {
  flex: none; display: inline-flex; align-items: center; gap: 7px; scroll-snap-align: start;
  padding: 4px 12px 4px 4px; border-radius: 999px; border: 1px solid rgba(var(--ink-rgb), 0.14);
  font: 400 13px var(--sans); color: var(--ink-2); text-decoration: none; white-space: nowrap;
  transition: background 0.2s, border-color 0.2s, transform 0.2s;
}
.rs-nav-a .line-icon, .rs-nav-home .line-icon { --s: 24px !important; }
.rs-nav-a:hover, .rs-nav-home:hover { border-color: rgba(var(--ink-rgb), 0.35); transform: translateY(-1px); }
.rs-nav-a.on, .rs-nav-home.on { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.rs-nav-a.on .line-icon, .rs-nav-home.on .line-icon { --ic: var(--bg) !important; background: transparent; border-color: rgba(var(--bg-rgb), 0.35); }

/* phone topic picker */
.rs-pick { display: none; }
@media (max-width: 760px) {
  .rs-nav-in { display: none; }
  .rs-pick { display: flex; align-items: stretch; gap: 8px; padding: 8px 12px; }
  .rs-pick-arrow {
    flex: none; width: 44px; display: grid; place-items: center; border-radius: 14px;
    border: 1px solid rgba(var(--ink-rgb), 0.16); color: var(--ink); text-decoration: none; font: 300 26px/1 var(--sans);
  }
  .rs-pick-d { flex: 1; min-width: 0; position: relative; }
  .rs-pick-d summary {
    list-style: none; cursor: pointer; display: flex; align-items: center; gap: 10px;
    padding: 7px 12px 7px 8px; border-radius: 14px; background: var(--ink); color: var(--bg);
  }
  .rs-pick-d summary::-webkit-details-marker { display: none; }
  .rs-pick-d summary .line-icon { --ic: var(--bg) !important; background: transparent; border-color: rgba(var(--bg-rgb), 0.35); }
  .rs-pick-label { display: flex; flex-direction: column; min-width: 0; flex: 1; line-height: 1.2; }
  .rs-pick-label small { font: 10px var(--mono); letter-spacing: 0.06em; opacity: 0.7; }
  .rs-pick-label b { font: 500 15px var(--sans); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
  .rs-pick-caret { transition: transform 0.25s; }
  .rs-pick-d[open] .rs-pick-caret { transform: rotate(180deg); }
  .rs-pick-menu {
    position: absolute; left: -56px; right: -56px; top: calc(100% + 8px); z-index: 60;
    max-height: 70vh; overflow-y: auto; padding: 12px; border-radius: 18px;
    background: var(--bg); border: 1px solid rgba(var(--ink-rgb), 0.16); box-shadow: 0 24px 50px -20px rgba(0, 0, 0, 0.5);
    animation: ixUp 0.25s var(--ease-out) both; transform: translateY(6px); opacity: 0;
  }
  .rs-pick-cat { font: 500 10px var(--mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--dim); margin: 12px 4px 6px; }
  .rs-pick-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
  .rs-pick-menu a { display: flex; align-items: center; gap: 8px; padding: 6px 8px 6px 6px; border-radius: 12px; border: 1px solid rgba(var(--ink-rgb), 0.12); color: var(--ink-2); text-decoration: none; font-size: 13px; line-height: 1.2; }
  .rs-pick-menu a.on { border-color: var(--accent); color: var(--accent); }
  .rs-pick-menu .line-icon { --s: 24px !important; flex: none; }
  .rs-pick-all { margin-bottom: 2px; }
  .rs-libtabs { flex-wrap: wrap; overflow: visible; }
}

/* ---- hero ---- */
.rs-page { padding-top: 36px; }
.rs-hero { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 40px; align-items: center; margin-bottom: 30px; }
.rs-hero h1 { font-size: clamp(34px, 4.6vw, 62px); line-height: 1.02; margin: 14px 0 16px; max-width: 16ch; }
.rs-hub-hero h1 { max-width: 20ch; }
.rs-hero .kicker a { color: inherit; text-decoration: none; border-bottom: 1px solid var(--faint); }
.rs-hero .kicker a:hover { color: var(--accent); }
.rs-lead { font-size: clamp(16px, 1.4vw, 19px); line-height: 1.6; color: var(--ink-2); max-width: 62ch; margin: 0 0 16px; }
.ix-art.rs-hero-art { width: clamp(150px, 20vw, 240px); height: clamp(150px, 20vw, 240px); border-radius: 32px; }
.ix-art.rs-hero-art svg { width: 78%; height: 78%; stroke-width: 2.2; }

/* ---- headline stats ---- */
.rs-stats { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; margin-bottom: 22px; }
.rs-stat { display: flex; flex-direction: column; gap: 8px; padding: 18px; border-radius: 16px; background: var(--panel-raised, var(--panel)); border: 1px solid rgba(var(--ink-rgb), 0.1); }
.rs-stat b { font: 300 clamp(34px, 3.6vw, 46px)/1 var(--sans); letter-spacing: -0.03em; color: var(--accent); font-variant-numeric: tabular-nums; }
.rs-stat span { font-size: 14px; line-height: 1.45; color: var(--ink-2); }
.rs-stat small { font: 10.5px/1.4 var(--mono); color: var(--dim); margin-top: auto; }

/* ---- on-page index ---- */
.rs-toc { display: flex; flex-wrap: wrap; gap: 6px; padding: 14px 0 6px; border-top: 1px solid var(--hair); margin-bottom: 8px; }
.rs-toc a { font: 500 12px var(--sans); color: var(--dim); text-decoration: none; padding: 5px 11px; border-radius: 999px; border: 1px solid transparent; }
.rs-toc a:hover { color: var(--ink); border-color: var(--faint); }

/* ---- sections ---- */
.rs-sec { padding: 54px 0 10px; border-top: 1px solid var(--hair); margin-top: 26px; }
.rs-sec-head { display: flex; gap: 18px; align-items: flex-start; margin-bottom: 22px; }
.rs-sec-n { font: 500 13px var(--mono); color: var(--accent); border: 1px solid rgba(var(--acc-rgb), 0.4); border-radius: 10px; padding: 6px 9px; margin-top: 4px; }
.rs-sec-head h2 { margin: 6px 0 0; }
.rs-prose { columns: 2 340px; column-gap: 40px; max-width: 1100px; }
.rs-prose p { margin: 0 0 16px; font-size: 16px; line-height: 1.7; color: var(--ink-2); break-inside: avoid; }
.rs-prose strong, .rs-list strong { color: var(--ink); font-weight: 500; }
.rs-intro { font-size: 16px; color: var(--ink-2); margin: -6px 0 20px; max-width: 70ch; }
.rs-note { font: 11px/1.5 var(--mono); color: var(--dim); margin: 10px 0 0; }

/* ---- diagram figure ---- */
.rs-fig { margin: 26px 0 0; padding: 22px; border-radius: 18px; background: var(--panel-raised, var(--panel)); display: grid; grid-template-columns: minmax(200px, 0.6fr) minmax(0, 1.6fr); gap: 26px; align-items: center; }
.rs-fig figcaption h3 { font: 500 19px/1.3 var(--sans); margin: 0 0 8px; }
.rs-fig figcaption p { margin: 0; color: var(--dim); font-size: 14px; line-height: 1.55; }
.dg-svg { width: 100%; height: auto; display: block; overflow: visible; }
.d-beat-fast, .d-beat-slow, .d-seesaw, .d-artery, .d-blob circle, .d-grow, .d-pop { transform-box: fill-box; }
.dg-box { fill: var(--bg); stroke: rgba(var(--ink-rgb), 0.3); stroke-width: 1.4; }
.dg-line { fill: none; stroke: var(--ink-2); stroke-width: 2.4; stroke-linecap: round; stroke-linejoin: round; }
.dg-dim { fill: none; stroke: rgba(var(--ink-rgb), 0.28); stroke-width: 1.4; stroke-linecap: round; }
.dg-grid { stroke: rgba(var(--ink-rgb), 0.08); stroke-dasharray: 2 4; }
.dg-acc { fill: none; stroke: var(--accent); stroke-width: 2.4; stroke-linecap: round; stroke-linejoin: round; }
.dg-good { stroke: var(--green); }
.dg-muted { stroke: rgba(var(--ink-rgb), 0.45); stroke-dasharray: 6 5; }
.dg-acc-fill { fill: rgba(var(--acc-rgb), 0.55); stroke: none; }
.dg-good-fill { fill: rgba(var(--green-rgb), 0.22); stroke: none; }
.dg-tint { fill: rgba(var(--acc-rgb), 0.09); stroke: none; }
.dg-bar { fill: rgba(var(--ink-rgb), 0.06); stroke: var(--ink-2); stroke-width: 1.6; }
.dg-bar.dg-good-fill { fill: rgba(var(--green-rgb), 0.2); stroke: var(--green); }
.dg-bar.dg-acc-fill { fill: rgba(var(--acc-rgb), 0.14); stroke: var(--accent); }
.dg-ring { fill: none; stroke: rgba(var(--ink-rgb), 0.2); stroke-width: 40; }
.dg-ring-good { stroke: rgba(var(--green-rgb), 0.5); }
.dg-ring-acc { stroke: rgba(var(--acc-rgb), 0.45); }
.dg-t, .dg-s { font: 11.5px var(--sans); fill: var(--dim); }
.dg-h { font: 500 14px var(--sans); fill: var(--ink); }
.dg-acc-t { font: 500 12px var(--sans); fill: var(--accent); }
.dg-good-t { font-weight: 500; fill: var(--green); }

/* diagram animations (paused until the figure scrolls into view) */
.d-beat-fast, .d-beat-slow { transform-origin: center; }
.d-beat-fast { animation: dBeat 0.83s ease-in-out infinite; }
.d-beat-slow { animation: dBeat 1.15s ease-in-out infinite; }
@keyframes dBeat { 0%, 100% { transform: scale(1); } 15% { transform: scale(1.07); } 30% { transform: scale(0.98); } 45% { transform: scale(1.04); } }
.d-draw { stroke-dasharray: var(--len, 1) calc(var(--len, 1) * 2); stroke-dashoffset: calc(var(--len, 1) * 1.05); animation: ixDraw 2.2s var(--ease-out) forwards; animation-delay: calc(0.2s + var(--i, 0) * 0.5s); }
.d-draw-loop { stroke-dasharray: var(--len, 1) calc(var(--len, 1) * 2); stroke-dashoffset: calc(var(--len, 1) * 1.05); animation: dDrawLoop 3.6s ease-in-out infinite; }
@keyframes dDrawLoop { 0% { stroke-dashoffset: calc(var(--len, 1) * 1.05); opacity: 1; } 60%, 85% { stroke-dashoffset: 0; opacity: 1; } 100% { stroke-dashoffset: 0; opacity: 0; } }
.d-pop { opacity: 0; animation: dPop 0.6s var(--ease-out) forwards; animation-delay: calc(0.2s + var(--i, 0) * 0.35s); }
@keyframes dPop { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }
.d-fade { opacity: 0; animation: ixFade 0.8s ease forwards; animation-delay: 1.4s; }
.d-grow { transform-origin: 50% 100%; transform: scaleY(0); animation: ixGrow 0.9s var(--ease-out) forwards; animation-delay: calc(0.15s + var(--i, 0) * 0.15s); }
.d-seesaw { transform-origin: center; animation: dSeesaw 4s ease-in-out infinite; }
@keyframes dSeesaw { 0%, 100% { transform: rotate(-6deg); } 50% { transform: rotate(6deg); } }
.d-artery { transform-origin: center; animation: dArtery 1s ease-in-out infinite; }
@keyframes dArtery { 0%, 100% { transform: scaleY(1); } 30% { transform: scaleY(1.22); } }
.d-flow { animation: dFlow 2.4s linear infinite; animation-delay: calc(var(--i, 0) * -0.8s); }
@keyframes dFlow { from { transform: translateX(0); opacity: 0; } 10% { opacity: 1; } 90% { opacity: 1; } to { transform: translateX(540px); opacity: 0; } }
.d-blob circle { transform-box: fill-box; transform-origin: center; animation: dBlob 2.6s ease-in-out infinite; }
.d-blob circle:nth-child(2n) { animation-delay: -1.3s; }
@keyframes dBlob { 0%, 100% { transform: scale(0.85); } 50% { transform: scale(1.15); } }
.d-arc { animation: dArc 1.2s var(--ease-out) both; animation-delay: calc(0.2s + var(--i, 0) * 0.4s); }
@keyframes dArc { from { stroke-dasharray: 0 999; } }

/* ---- how it works flow ---- */
.rs-flow { position: relative; display: grid; grid-template-columns: repeat(var(--n), minmax(0, 1fr)); gap: 18px; }
.rs-flow-line { position: absolute; left: 12%; right: 12%; top: 34px; width: 76%; height: 6px; z-index: 0; overflow: visible; }
.rs-flow-line path { stroke: rgba(var(--ink-rgb), 0.25); stroke-width: 1.5; stroke-dasharray: 4 4; vector-effect: non-scaling-stroke; fill: none; }
.rs-flow-dot { fill: var(--accent); animation: rsDot 4s linear infinite; }
@keyframes rsDot { from { transform: translateX(0); } to { transform: translateX(100px); } }
.rs-step { position: relative; z-index: 1; text-align: center; padding: 0 6px; opacity: 0; transform: translateY(14px); }
.rv.in .rs-step { animation: ixUp 0.6s var(--ease-out) forwards; animation-delay: calc(0.1s + var(--i) * 0.18s); }
.rs-step-ic { position: relative; display: inline-grid; place-items: center; width: 70px; height: 70px; border-radius: 22px; background: var(--bg); border: 1px solid rgba(var(--ink-rgb), 0.16); margin-bottom: 12px; }
.rs-step-ic .line-icon { border: 0; background: transparent; }
.rs-step-n { position: absolute; top: -8px; right: -8px; width: 22px; height: 22px; border-radius: 50%; background: var(--accent); color: var(--on-accent); font: 600 11px/22px var(--mono); }
.rs-step h4 { font: 500 16px var(--sans); margin: 0 0 6px; }
.rs-step p { margin: 0; font-size: 14px; line-height: 1.5; color: var(--dim); }

/* ---- measure ---- */
.rs-two { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr); gap: 32px; align-items: start; }
.rs-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 14px; }
.rs-list li { position: relative; padding-left: 22px; font-size: 15px; line-height: 1.6; color: var(--ink-2); }
.rs-list li::before { content: ""; position: absolute; left: 2px; top: 11px; width: 10px; height: 1.5px; background: var(--accent); }
.rs-tools { display: grid; gap: 16px; }
.rs-scale, .rs-calc, .rs-quiz { padding: 18px 20px; border-radius: 16px; background: var(--panel-raised, var(--panel)); }
.rs-scale-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; flex-wrap: wrap; margin-bottom: 14px; }
.rs-scale-out b { font: 400 30px var(--sans); letter-spacing: -0.02em; font-variant-numeric: tabular-nums; }
.rs-scale-out small { color: var(--dim); font-size: 12px; }
.rs-scale-band { display: inline-block; margin-left: 8px; font: 600 12px var(--sans); padding: 3px 10px; border-radius: 999px; border: 1px solid currentColor; }
.rs-scale-band.rs-good { color: var(--green); } .rs-scale-band.rs-mid { color: var(--ink-2); } .rs-scale-band.rs-bad { color: var(--accent); }
.rs-scale-track { position: relative; display: flex; height: 34px; border-radius: 10px; overflow: visible; gap: 3px; }
.rs-band { position: relative; border-radius: 6px; display: flex; align-items: flex-end; padding: 0 6px 4px; min-width: 0; }
.rs-band em { font: normal 500 10px/1.1 var(--sans); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.rs-band.rs-good { background: rgba(var(--green-rgb), 0.2); color: var(--green); }
.rs-band.rs-mid { background: rgba(var(--ink-rgb), 0.08); color: var(--dim); }
.rs-band.rs-bad { background: rgba(var(--acc-rgb), 0.16); color: var(--accent); }
.rs-scale-pin { position: absolute; top: -6px; bottom: -6px; width: 3px; margin-left: -1.5px; border-radius: 3px; background: var(--ink); left: 50%; transition: left 0.35s var(--ease-out); box-shadow: 0 0 0 3px rgba(var(--bg-rgb), 0.8); }
.rs-scale-ends { display: flex; justify-content: space-between; font: 10.5px var(--mono); color: var(--dim); margin-top: 6px; }
.rs-scale-in { width: 100%; margin-top: 10px; accent-color: var(--accent); }
.rs-calc label { display: flex; justify-content: space-between; align-items: center; gap: 12px; font-size: 14px; color: var(--ink-2); margin-top: 12px; }
.rs-calc input, .rs-quiz input[type="number"] { width: 92px; font: 500 16px var(--sans); padding: 7px 10px; border-radius: 10px; border: 1px solid var(--faint); background: var(--bg); color: var(--ink); }
.rs-calc-out { margin: 14px 0 0; font-size: 15px; }
.rs-calc-out b { font: 500 22px var(--sans); color: var(--accent); }
.rs-quiz fieldset { border: 0; padding: 0; margin: 14px 0 0; }
.rs-quiz legend { font-size: 14.5px; color: var(--ink); margin-bottom: 8px; }
.rs-quiz label { display: inline-flex; align-items: center; gap: 6px; margin: 0 8px 6px 0; font-size: 13px; padding: 6px 12px; border-radius: 999px; border: 1px solid var(--faint); cursor: pointer; }
.rs-quiz label:has(input:checked) { border-color: var(--accent); color: var(--accent); }
.rs-quiz input { accent-color: var(--accent); margin: 0; }

/* ---- research ---- */
.rs-body .topbar { grid-template-columns: auto minmax(0, 1fr) auto; grid-template-areas: "brand tabs actions"; }
.rs-body .tabs { margin-inline: auto; }
@media (max-width: 900px) {
  .rs-body .topbar { grid-template-areas: "brand . actions" "tabs tabs tabs"; }
  .rs-body .tabs { margin: 0; }
}
.rs-chart-row { display: grid; grid-template-columns: minmax(0, 1.7fr) minmax(220px, 0.8fr); gap: 22px; align-items: start; margin-bottom: 22px; }
.rs-chart-aside { padding: 8px 4px; }
.rs-chart-aside h3 { font: 500 18px var(--sans); margin: 0 0 8px; }
.rs-chart-aside p { margin: 0 0 12px; font-size: 14.5px; line-height: 1.6; color: var(--ink-2); }
.rs-tip a { color: var(--accent); }
.rs-ev-box { margin-top: 18px; padding: 14px 16px; border-radius: 14px; border: 1px solid rgba(var(--ink-rgb), 0.12); }
.rs-ev-box p { margin: 6px 0 0; font-size: 13px; color: var(--dim); }
.rs-chart { margin: 0; padding: 14px 14px 10px; border-radius: 16px; background: var(--bg); border: 1px solid rgba(var(--ink-rgb), 0.1); max-width: 860px; }
.rs-chart .ix-chart { max-height: 420px; }
.rs-mark-line { stroke: var(--accent); stroke-width: 1.2; stroke-dasharray: 3 3; }
.rs-mark circle { fill: var(--accent); }
.rs-mark .ix-you-ring { fill: rgba(var(--acc-rgb), 0.18); animation: ixPulse 2s ease-out infinite; transform-box: fill-box; transform-origin: center; }
.rs-mark-t { font: 600 11px var(--sans); fill: var(--accent); }
.rs-studies { display: grid; grid-template-columns: repeat(auto-fill, minmax(290px, 1fr)); gap: 14px; }
.rs-study { display: flex; flex-direction: column; gap: 8px; padding: 18px; border-radius: 16px; border: 1px solid rgba(var(--ink-rgb), 0.12); background: var(--bg); transition: border-color 0.2s, transform 0.2s; }
.rs-study:hover { border-color: rgba(var(--ink-rgb), 0.3); transform: translateY(-2px); }
.rs-study-top { display: flex; align-items: center; gap: 10px; }
.rs-year { font: 600 12px var(--mono); color: var(--accent); }
.rs-journal { font: 11px var(--mono); color: var(--dim); text-transform: uppercase; letter-spacing: 0.06em; }
.rs-study h3 { font: 500 17px/1.3 var(--sans); margin: 0; }
.rs-n { display: flex; align-items: center; gap: 8px; margin: 0; font: 12px var(--mono); color: var(--dim); }
.rs-n .line-icon { --s: 22px !important; }
.rs-study p { margin: 0; font-size: 14px; line-height: 1.55; color: var(--ink-2); }
.rs-pub { margin-top: auto; padding-top: 6px; font: 500 12px var(--sans); color: var(--dim); text-decoration: none; }
.rs-pub:hover { color: var(--accent); }

/* ---- improve ---- */
.rs-plan { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 12px; }
.rs-plan li { display: flex; gap: 14px; padding: 16px; border-radius: 14px; border: 1px solid rgba(var(--ink-rgb), 0.12); }
.rs-plan-n { flex: none; width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center; font: 600 12px var(--mono); color: var(--green); border: 1.5px solid var(--green); }
.rs-plan h4 { font: 500 15.5px var(--sans); margin: 3px 0 4px; }
.rs-plan p { margin: 0; font-size: 14px; line-height: 1.5; color: var(--dim); }
.rs-week { margin-top: 18px; padding: 18px; border-radius: 16px; background: var(--panel-raised, var(--panel)); }
.rs-week-grid { display: grid; grid-template-columns: repeat(7, minmax(0, 1fr)); gap: 8px; margin-top: 12px; }
.rs-week-grid div { display: flex; flex-direction: column; gap: 6px; padding: 12px 10px; border-radius: 12px; background: var(--bg); border: 1px solid var(--hair); }
.rs-week-grid b { font: 600 11px var(--mono); color: var(--accent); text-transform: uppercase; letter-spacing: 0.08em; }
.rs-week-grid span { font-size: 13px; line-height: 1.35; color: var(--ink-2); }

/* ---- myths & faq ---- */
.rs-myths { display: grid; grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); gap: 12px; }
.rs-myth { border-radius: 16px; border: 1px solid rgba(var(--ink-rgb), 0.12); overflow: hidden; }
.rs-myth p { margin: 0; padding: 14px 16px; font-size: 14.5px; line-height: 1.55; }
.rs-myth span { display: block; font: 600 10.5px var(--mono); letter-spacing: 0.1em; text-transform: uppercase; margin-bottom: 4px; }
.rs-m { color: var(--dim); text-decoration: line-through; text-decoration-color: rgba(var(--acc-rgb), 0.5); }
.rs-m span { color: var(--accent); text-decoration: none; }
.rs-f { background: rgba(var(--green-rgb), 0.07); border-top: 1px solid var(--hair); color: var(--ink-2); }
.rs-f span { color: var(--green); }
.rs-faq { display: grid; gap: 8px; max-width: 900px; }
.rs-faq details { border-radius: 14px; padding: 0; background: var(--panel-raised, var(--panel)); }
.rs-faq summary { cursor: pointer; padding: 15px 18px; font: 500 15px var(--sans); list-style: none; display: flex; justify-content: space-between; gap: 12px; }
.rs-faq summary::-webkit-details-marker { display: none; }
.rs-faq summary::after { content: "+"; color: var(--accent); font: 400 20px/1 var(--sans); transition: transform 0.25s; }
.rs-faq details[open] summary::after { transform: rotate(45deg); }
.rs-faq details p { margin: 0; padding: 0 18px 16px; color: var(--ink-2); font-size: 14.5px; line-height: 1.6; }

/* ---- sources, related, pager ---- */
.rs-refs { margin: 0 0 26px; padding-left: 20px; display: grid; gap: 8px; font-size: 13.5px; color: var(--ink-2); max-width: 980px; }
.rs-refs a, .rs-foot a { color: var(--dim); }
.rs-refs a:hover, .rs-foot a:hover { color: var(--accent); }
.rs-related, .rs-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 12px; }
.rs-card { position: relative; display: flex; gap: 14px; align-items: center; padding: 14px; border-radius: 18px; border: 1px solid rgba(var(--ink-rgb), 0.12); background: var(--bg); color: var(--ink); text-decoration: none; transition: border-color 0.2s, transform 0.25s var(--ease-out), box-shadow 0.25s; }
.rs-card:hover { border-color: rgba(var(--ink-rgb), 0.35); transform: translateY(-3px); box-shadow: 0 12px 30px -18px rgba(0, 0, 0, 0.45); }
.rs-card .ix-art { width: 76px; height: 76px; border-radius: 16px; }
.rs-card .ix-art svg { width: 60px; height: 60px; }
.rs-card-body { display: flex; flex-direction: column; gap: 3px; min-width: 0; flex: 1; }
.rs-card-body .ix-ev { margin: 0; }
.rs-card-t { font: 500 17px var(--sans); }
.rs-card-stat { font-size: 12.5px; line-height: 1.4; color: var(--dim); display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.rs-card-stat b { color: var(--accent); font-weight: 600; }
.rs-card-go { color: var(--dim); font-size: 18px; transition: transform 0.2s, color 0.2s; }
.rs-card:hover .rs-card-go { transform: translateX(4px); color: var(--accent); }
.rs-hub-group { margin: 34px 0; }
.rs-hub-group > .kicker { margin-bottom: 14px; }
.rs-pager { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 56px; }
.rs-pager a { display: flex; flex-direction: column; gap: 4px; padding: 18px 20px; border-radius: 16px; border: 1px solid rgba(var(--ink-rgb), 0.14); color: var(--ink); text-decoration: none; transition: border-color 0.2s; }
.rs-pager a:last-child { text-align: right; }
.rs-pager a:hover { border-color: var(--accent); }
.rs-pager small { font: 11px var(--mono); color: var(--dim); text-transform: uppercase; letter-spacing: 0.1em; }
.rs-pager span { font: 400 20px var(--sans); }
.rs-foot { max-width: 1380px; margin: 0 auto; padding: 28px var(--gutter) 60px; border-top: 1px solid var(--hair); font-size: 13px; color: var(--dim); }
.rs-foot p { margin: 6px 0; }

/* ---- library block on the main page ---- */
.rs-lib { margin-bottom: 40px; }
.rs-libtabs { display: flex; gap: 8px; overflow-x: auto; scrollbar-width: none; padding: 2px 2px 14px; }
.rs-libtabs::-webkit-scrollbar { display: none; }
.rs-libtabs .ix-tab { text-decoration: none; flex: none; }
.rs-lib-group { margin-top: 18px; }
.rs-lib-cat { font: 500 10.5px var(--mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--dim); margin-bottom: 10px; }
.rs-lib .impact-head a { color: var(--accent); text-decoration: none; }

/* ---- reveal on scroll ---- */
.rv { opacity: 0; transform: translateY(16px); transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out); transition-delay: calc(var(--i, 0) * 0.07s); }
.rv.in { opacity: 1; transform: none; }
.rv:not(.in) *, .dg:not(.in) *, .rs-chart:not(.in) * { animation-play-state: paused !important; }
.rs-sec.rv { transform: none; opacity: 1; }
.no-js .rv { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .rv, .rs-step { opacity: 1 !important; transform: none !important; transition: none; animation: none !important; }
  .dg-svg *, .rs-flow-dot, .rs-mark .ix-you-ring { animation: none !important; opacity: 1 !important; transform: none !important; stroke-dashoffset: 0 !important; }
}

@media (max-width: 960px) {
  .rs-chart-row { grid-template-columns: 1fr; }
  .rs-two, .rs-fig { grid-template-columns: 1fr; }
  .rs-flow { grid-template-columns: repeat(2, minmax(0, 1fr)); row-gap: 28px; }
  .rs-flow-line { display: none; }
  .rs-week-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}
.rs-scroll, .rs-chart .ix-chart-wrap { min-width: 0; }
@media (max-width: 600px) {
  .rs-scroll, .rs-chart .ix-chart-wrap { overflow-x: auto; scrollbar-width: thin; margin: 0 -4px; padding-bottom: 4px; }
  .rs-scroll .dg-svg { min-width: 520px; }
  .rs-chart .ix-chart { min-width: 480px; }
  .rs-page { padding-top: 22px; }
  .rs-hero { grid-template-columns: 1fr; gap: 18px; }
  .rs-hero-art { order: -1; }
  .ix-art.rs-hero-art { width: 120px; height: 120px; border-radius: 24px; }
  .rs-stats { grid-template-columns: 1fr; }
  .rs-stat { flex-direction: row; flex-wrap: wrap; align-items: baseline; gap: 4px 14px; padding: 14px 16px; }
  .rs-stat b { font-size: 30px; min-width: 88px; }
  .rs-stat span { flex: 1; min-width: 0; }
  .rs-stat small { flex-basis: 100%; }
  .rs-sec { padding-top: 38px; }
  .rs-flow { grid-template-columns: 1fr; text-align: left; }
  .rs-step { display: grid; grid-template-columns: 64px 1fr; column-gap: 14px; text-align: left; }
  .rs-step-ic { grid-row: span 2; width: 60px; height: 60px; margin: 0; }
  .rs-step h4 { align-self: end; }
  .rs-week-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .rs-myths, .rs-studies, .rs-plan, .rs-related, .rs-grid { grid-template-columns: 1fr; }
  .rs-fig { padding: 14px; }
  .rs-pager span { font-size: 16px; }
}

/* ============================================================================
   CALM LAYER: square hairline cards, plain-text topic menu, quiet numbers.
   Matches the calm layer at the end of styles.css.
   ============================================================================ */
.rs-nav { background: rgba(var(--bg-rgb), 0.82); border-bottom: 1px solid var(--hair); }
.rs-nav-in { gap: 20px; }
.rs-nav-a, .rs-nav-home,
.rs-nav-a:hover, .rs-nav-home:hover,
.rs-nav-a.on, .rs-nav-home.on {
  border: none; background: none; border-radius: 0; transform: none; box-shadow: none;
  padding: 6px 0;
}
.rs-nav-a, .rs-nav-home { color: var(--dim); position: relative; font-size: 13px; }
.rs-nav-a:hover, .rs-nav-home:hover, .rs-nav-a.on, .rs-nav-home.on { color: var(--ink); }
.rs-nav-a.on::after { content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 1px; background: var(--accent); }
.rs-nav-a .line-icon, .rs-nav-home .line-icon { display: none !important; }
.rs-nav-group { color: var(--dim); opacity: 0.7; }

.ix-art, .ix-art.rs-hero-art { border: none; background: none; border-radius: 0; }

.rs-stat, .rs-fig, .rs-scale, .rs-calc, .rs-quiz, .rs-ev-box, .rs-chart, .rs-study,
.rs-plan li, .rs-week, .rs-week-grid div, .rs-myth, .rs-faq details, .rs-card, .rs-pager a {
  border-radius: var(--radius);
  border: 1px solid var(--faint);
  background: rgba(var(--bg-rgb), 0.55);
  box-shadow: none;
}
.rs-card:hover, .rs-pager a:hover { transform: none; background: var(--surface-hover); }
.rs-sec-n { color: var(--dim); border: none; padding: 6px 0; font-weight: 400; }
.rs-toc a { border-radius: 2px; }
.rs-step-ic { border-radius: var(--radius); background: transparent; }
.rs-quiz label, .rs-scale-band { border-radius: 2px; }
.rs-calc input, .rs-quiz input[type="number"] { border-radius: 2px; }
.rs-h1, .rs-hero h1 { font-family: var(--display); font-weight: 300; }

@media (max-width: 760px) {
  .rs-pick-arrow { border-radius: 2px; border-color: var(--faint); }
  .rs-pick-d summary,
  .rs-pick-d[open] summary { border-radius: 2px; background: transparent; color: var(--ink); border: 1px solid var(--faint); }
  .rs-pick-d summary .line-icon { --ic: var(--ink-2) !important; }
  .rs-pick-menu { border-radius: var(--radius); }
  .rs-pick-menu a { border-radius: 2px; }
}
.rs-nav-in {
  max-width: 1180px;
  mask-image: linear-gradient(90deg, transparent 0, #000 var(--gutter), #000 calc(100% - var(--gutter)), transparent 100%);
}

/* ---- Extended library: every concept icon draws itself in, then floats ---- */
.rs-step-ic .line-icon, .rs-plan-ic .line-icon { animation: icFloat 4.2s ease-in-out infinite; animation-delay: calc(var(--i, 0) * -0.7s); }
.rv.in .rs-step-ic .ios-glyph > *, .rs-plan li.rv.in .rs-plan-ic .ios-glyph > * {
  stroke-dasharray: 90; stroke-dashoffset: 90;
  animation: icDraw 1.6s var(--ease-out) forwards; animation-delay: calc(0.25s + var(--i, 0) * 0.18s);
}
@keyframes icDraw { to { stroke-dashoffset: 0; } }
@keyframes icFloat { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-3px); } }
.rs-plan-ic { position: relative; flex: none; display: grid; place-items: center; width: 48px; height: 48px; border: 1px solid var(--faint); border-radius: var(--radius); }
.rs-plan-ic .line-icon { border: 0; background: transparent; }
.rs-plan-ic .rs-plan-n { position: absolute; top: -8px; right: -8px; width: 20px; height: 20px; font-size: 10px; border-width: 1px; background: var(--bg); }
.d-grow-x { transform-box: fill-box; transform-origin: 0 50%; transform: scaleX(0); animation: dGrowX 0.9s var(--ease-out) forwards; animation-delay: calc(0.15s + var(--i, 0) * 0.08s); }
@keyframes dGrowX { to { transform: scaleX(1); } }
@media (prefers-reduced-motion: reduce) {
  .rs-step-ic *, .rs-plan-ic * { animation: none !important; stroke-dashoffset: 0 !important; transform: none !important; }
}

/* ---- Evidence check cards ---- */
.rs-claims { display: grid; grid-template-columns: repeat(auto-fill, minmax(290px, 1fr)); gap: 12px; margin-top: 22px; }
.rs-claim { padding: 16px 18px; border: 1px solid rgba(var(--ink-rgb), 0.12); border-radius: 16px; }
.rs-claim h3 { font: 500 16px/1.35 var(--sans); margin: 6px 0 6px; }
.rs-claim p { margin: 0; font-size: 14px; line-height: 1.55; color: var(--ink-2); }
.rs-claim .rs-claim-src { margin-top: 10px; display: flex; flex-wrap: wrap; gap: 4px 12px; }
.rs-claim-src a { font: 500 12px var(--sans); color: var(--dim); }
.rs-claim-src a:hover { color: var(--ink); }
.rs-fig + .rs-fig { margin-top: 14px; }

/* New research (2025–26): pill, tags, change box */
.rs-new-pill { display: inline-flex; align-items: center; gap: 8px; margin-top: 12px; font: 500 11px var(--mono); letter-spacing: 0.04em; text-transform: uppercase; color: var(--accent); text-decoration: none; border-bottom: 1px solid rgba(var(--acc-rgb), 0.35); padding-bottom: 2px; }
.rs-new-pill:hover { border-bottom-color: var(--accent); }
.rs-new-pill i { width: 7px; height: 7px; border-radius: 50%; background: var(--accent); animation: rsNewPulse 2.4s ease-in-out infinite; }
.ix-ev + .rs-new-pill { margin-left: 14px; }
@keyframes rsNewPulse { 0%, 100% { box-shadow: 0 0 0 0 rgba(var(--acc-rgb), 0.45); } 60% { box-shadow: 0 0 0 7px rgba(var(--acc-rgb), 0); } }
.rs-new-tag { font: 500 10px var(--mono); letter-spacing: 0.06em; text-transform: uppercase; color: var(--accent); border: 1px solid rgba(var(--acc-rgb), 0.45); padding: 1px 6px; }
.rs-new-topic { display: inline-flex; align-items: center; gap: 6px; font: 500 12px var(--mono); color: var(--dim); text-decoration: none; }
.rs-new-topic:hover { color: var(--accent); }
.rs-new-foot { display: flex; align-items: center; justify-content: space-between; gap: 10px; flex-wrap: wrap; margin-top: auto; padding-top: 4px; }
.rs-new-foot .ix-ev { margin: 0; }
.rs-new-change { margin-top: 18px; padding: 16px 18px; border-left: 2px solid var(--accent); }
.rs-new-change p { margin: 6px 0 0; color: var(--ink-2); max-width: 75ch; }
@media (prefers-reduced-motion: reduce) { .rs-new-pill i { animation: none; } }
.d-grow.d-grow-down { transform-origin: 50% 0; }

/* ---- Flip-card quiz: claim on the front, verdict and reason on the back ---- */
.fc-bar { display: grid; gap: 12px; margin: 18px 0 20px; }
.fc-filters { display: flex; flex-wrap: wrap; gap: 6px; }
.fc-filters button, .fc-score button {
  font: 500 11px var(--mono); letter-spacing: 0.05em; text-transform: uppercase;
  color: var(--dim); background: none; border: 1px solid var(--faint); border-radius: 2px;
  padding: 7px 10px; cursor: pointer;
}
.fc-filters button i { font-style: normal; opacity: 0.6; margin-left: 4px; }
.fc-filters button:hover, .fc-score button:hover { color: var(--ink); border-color: rgba(var(--ink-rgb), 0.35); }
.fc-filters button.on { color: var(--ink); border-color: var(--ink-2); }
.fc-score { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 18px; font: 500 11px var(--mono); letter-spacing: 0.05em; text-transform: uppercase; color: var(--dim); }
.fc-score b { color: var(--ink); font-weight: 500; }
.fc-score button:first-of-type { margin-left: auto; }
.fc-prog { height: 1px; background: var(--hair); overflow: hidden; }
.fc-prog i { display: block; height: 100%; background: var(--accent); transform-origin: 0 50%; transform: scaleX(0); transition: transform 0.5s var(--ease-out); }
.fc-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 12px; }
.fc { perspective: 1200px; cursor: pointer; }
.fc[hidden] { display: none; }
.fc-in { display: grid; min-height: 248px; transition: transform 0.6s var(--ease-out); transform-style: preserve-3d; }
.fc.flipped .fc-in { transform: rotateY(180deg); }
.fc-face {
  grid-area: 1 / 1; display: flex; flex-direction: column; gap: 14px; padding: 18px;
  border: 1px solid var(--faint); border-radius: var(--radius); background: var(--bg);
  -webkit-backface-visibility: hidden; backface-visibility: hidden;
}
.fc-back { transform: rotateY(180deg); }
.fc:hover .fc-face { border-color: rgba(var(--ink-rgb), 0.3); }
.fc-top { display: flex; justify-content: space-between; gap: 10px; font: 500 10.5px var(--mono); letter-spacing: 0.08em; text-transform: uppercase; color: var(--dim); }
.fc-q { margin: 0; flex: 1; font: 300 20px/1.32 var(--display); color: var(--ink); }
.fc-recap { margin: 0; font-size: 13px; line-height: 1.45; color: var(--dim); }
.fc-a { margin: 0; flex: 1; font-size: 14.5px; line-height: 1.6; color: var(--ink-2); }
.fc-opts { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; }
.fc-opts button {
  font: 500 11px var(--mono); letter-spacing: 0.06em; text-transform: uppercase;
  padding: 9px 4px; background: none; color: var(--ink-2); border: 1px solid var(--faint); border-radius: 2px; cursor: pointer;
}
.fc-opts button:hover, .fc-opts button:focus-visible { color: var(--ink); border-color: var(--ink-2); }
.fc-peek, .fc-back-btn { align-self: flex-start; background: none; border: 0; padding: 0; cursor: pointer; font: 500 11px var(--mono); letter-spacing: 0.06em; text-transform: uppercase; color: var(--dim); }
.fc-peek:hover, .fc-back-btn:hover { color: var(--accent); }
.fc-foot { display: flex; justify-content: space-between; align-items: center; gap: 10px; }
.fc-foot a { font: 500 11px var(--mono); letter-spacing: 0.04em; text-transform: uppercase; color: var(--dim); text-decoration: none; border-bottom: 1px solid var(--faint); }
.fc-foot a:hover { color: var(--accent); }
.fc-verdict { color: var(--ink); }
.fc[data-v="true"] .fc-verdict { color: var(--green); }
.fc[data-v="myth"] .fc-verdict { color: var(--accent); }
.fc-verdict::before { content: ""; display: inline-block; width: 7px; height: 7px; margin-right: 7px; border: 1px solid currentColor; border-radius: 50%; vertical-align: 1px; }
.fc[data-v="true"] .fc-verdict::before { background: currentColor; }
.fc[data-r="right"] .fc-res { color: var(--green); }
.fc[data-r="miss"] .fc-res { color: var(--accent); }
.fc[data-r] .fc-front .fc-top span:first-child::after { content: " · answered"; }
.fc-empty { color: var(--dim); font-size: 14px; }
.rs-quiz-link { display: inline-block; margin-top: 12px; margin-left: 14px; font: 500 11px var(--mono); letter-spacing: 0.04em; text-transform: uppercase; color: var(--ink-2); text-decoration: none; border-bottom: 1px solid var(--faint); padding-bottom: 2px; }
.rs-quiz-link:hover { color: var(--accent); border-bottom-color: var(--accent); }
@media (max-width: 760px) {
  .fc-grid { grid-template-columns: 1fr; }
  .fc-score button:first-of-type { margin-left: 0; }
  .fc-in { min-height: 220px; }
}
@media (prefers-reduced-motion: reduce) {
  .fc-in { transition: none; }
}

/* ============================================================================
   CALM LAYER, PART 3: cleaner topic pages. The Topics menu in the top bar
   lists every page, so the second scrolling topic strip goes; section
   headings sit flush left with one spacing rhythm.
   ============================================================================ */
.rs-nav { display: none !important; }
.rs-sec { padding: 72px 0 8px; margin-top: 40px; }
.rs-sec-head { display: block; margin-bottom: 28px; }
.rs-sec-n { display: none; }
.rs-sec-head h2 { margin: 10px 0 0; font-size: clamp(28px, 3.2vw, 40px); line-height: 1.1; }
.rs-hero { margin-bottom: 48px; }
.rs-intro { margin: 0 0 28px; color: var(--dim); }
.rs-stats, .rs-studies, .rs-grid, .rs-related, .rs-claims, .fc-grid { gap: 16px; }
.rs-claim { border-radius: var(--radius); border-color: var(--faint); }
.rs-toc { gap: 4px 18px; padding: 16px 0; }
.rs-toc a { padding: 4px 0; border: none; }
.rs-toc a:hover { border: none; }
.fc-face { padding: 22px; }
@media (max-width: 760px) {
  .rs-sec { padding-top: 48px; margin-top: 24px; }
  .rs-hero { margin-bottom: 32px; }
}