:root {
  --mechanism-paper: var(--surface);
  --mechanism-paper-2: #1a1d20;
  --mechanism-paper-ink: var(--ink);
  --mechanism-paper-muted: var(--muted);
  --mechanism-line: rgba(238, 240, 243, 0.155);
  --mechanism-frost: rgba(30, 33, 36, 0.94);
  --mechanism-frost-strong: rgba(30, 33, 36, 0.94);
  --mechanism-red: var(--brand);
  --mechanism-cobalt: var(--bio);
  --mechanism-violet: var(--violet);
  --mechanism-amber: var(--amber);
}

.page-mechanisms {
  background:
    radial-gradient(900px 520px at 84% 2%, color-mix(in srgb, var(--bio) 4%, transparent), transparent 68%),
    radial-gradient(700px 560px at -8% 42%, color-mix(in srgb, var(--brand) 4%, transparent), transparent 70%),
    var(--surface);
}

.page-mechanisms main { overflow: clip; }

.mechanisms-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(430px, .8fr);
  width: min(100%, 1500px);
  min-height: 0;
  align-items: center;
  gap: 24px;
  padding: 20px 24px 20px;
  margin: auto;
}

.mechanisms-hero-copy h1 {
  max-width: 810px;
  margin: 1rem 0 1.35rem;
  font-size: 24px;
  font-weight: 500;
  line-height: .94;
  letter-spacing: -.01em;
}

.mechanisms-hero-copy > p {
  max-width: 720px;
  margin: 0;
  color: var(--ink-soft);
  font-size: clamp(1rem, 1.45vw, 1.2rem);
  line-height: 1.65;
}

.mechanisms-hero-actions { display: flex; flex-wrap: wrap; gap: .7rem; margin-top: 1.35rem; }

.mechanisms-hero-register {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  padding: 0;
  margin: 1.6rem 0 0;
  border-block: 1px solid var(--mechanism-line);
}

.mechanisms-hero-register div { padding: .95rem; border-right: 1px solid var(--mechanism-line); }
.mechanisms-hero-register div:first-child { padding-left: 0; }
.mechanisms-hero-register div:last-child { border-right: 0; }
.mechanisms-hero-register dt { color: var(--dim); font: 650 .75rem/1.35 var(--mono);   }
.mechanisms-hero-register dd { margin: .32rem 0 0; color: var(--bio); font: 700 .82rem/1.3 var(--mono); }

.mechanisms-hero-figure { position: relative; margin: 0; }
.mechanisms-hero-figure::before { position: absolute; inset: 10% 0 -8% 9%; content: ""; border-radius: 50%; background: color-mix(in srgb, var(--violet) 7%, transparent); filter: blur(65px); }
.mechanisms-hero-figure svg { position: relative; width: min(100%, 450px); height: auto; margin-inline: auto; }
.mechanisms-hero-figure figcaption { position: relative; max-width: 600px; padding: 1rem 1.15rem; margin: -1.2rem 1.5rem 0; border: 1px solid var(--mechanism-line); border-radius: 6px; background: rgba(30, 33, 36, 0.94); box-shadow: 0 18px 60px rgba(0, 0, 0, 0.203); backdrop-filter: blur(18px); color: var(--muted); font-size: .82rem; }
.mechanisms-hero-figure figcaption span { display: block; margin-bottom: .2rem; color: var(--ink); font: 700 .75rem var(--mono);   }

.mechanism-workspace {
  width: min(calc(100% - 24px), 1580px);
  margin: 0 auto 24px;
  scroll-margin-top: calc(var(--fg-sticky-top) + 12px);
}

.mechanism-workspace-intro {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, .55fr);
  align-items: end;
  gap: 24px;
  padding: 17px clamp(0rem, 1.7vw, 1.5rem) 1rem;
  border-top: 1px solid var(--mechanism-line);
}

.mechanism-workspace-intro h2 {
  max-width: 850px;
  margin: .75rem 0 0;
  font-size: 20px;
  font-weight: 500;
  line-height: 1;
  letter-spacing: -.01em;
}

.mechanism-workspace-intro > p { max-width: 580px; margin: 0; color: var(--muted); }

.mechanism-mobile-picker { display: none; gap: .45rem; margin-bottom: 1rem; }
.mechanism-mobile-picker label { color: var(--brand-bright); font: 700 .75rem var(--mono);   }
.mechanism-mobile-picker select { width: 100%; min-height: 48px; padding: .65rem .8rem; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--surface-raised); color: var(--ink); }

.mechanism-workspace-grid {
  display: grid;
  grid-template-columns: minmax(245px, 290px) minmax(560px, 1fr) minmax(245px, 290px);
  align-items: start;
  gap: clamp(.75rem, 1.2vw, 1.25rem);
}

.mechanism-family-rail,
.mechanism-evidence-inspector,
.mechanism-stage {
  border: 1px solid var(--mechanism-line);
  border-radius: 6px;
  background: linear-gradient(150deg, rgba(238, 240, 243, 0.017), transparent 34%), var(--mechanism-frost);
  box-shadow: 0 25px 80px rgba(0, 0, 0, 0.14);
  backdrop-filter: blur(24px) saturate(1.12);
}

.mechanism-family-rail { position: sticky; top: calc(var(--fg-sticky-top) + 12px); max-height: calc(100svh - var(--fg-sticky-top) - 24px); padding: .85rem; overflow: hidden; }
.mechanism-search { position: relative; display: grid; gap: .42rem; }
.mechanism-search > span { color: var(--dim); font: 700 .75rem var(--mono);   }
.mechanism-search input { width: 100%; min-height: 44px; padding: .64rem 2.4rem .64rem .72rem; border: 1px solid var(--mechanism-line); border-radius: 6px; outline: 0; background: rgba(238, 240, 243, 0.112); color: var(--ink); font-size: .77rem; }
.mechanism-search input:focus { border-color: color-mix(in srgb, var(--brand) 70%, transparent); box-shadow: 0 0 0 3px color-mix(in srgb, var(--brand) 5%, transparent); }
.mechanism-search kbd { position: absolute; right: .65rem; bottom: .72rem; padding: .05rem .35rem; border: 1px solid var(--line); border-radius: 5px; color: var(--dim); background: rgba(238, 240, 243, 0.02); font: .75rem var(--mono); }

.mechanism-category-chips { display: flex; gap: .35rem; padding: .7rem 0 .1rem; overflow-x: auto; scrollbar-width: thin; }
.mechanism-category-chips button { display: inline-flex; min-height: 34px; flex: 0 0 auto; align-items: center; gap: .4rem; padding: .3rem .56rem; border: 1px solid var(--mechanism-line); border-radius: 5px; background: transparent; color: var(--muted); font: 650 .75rem var(--mono); }
.mechanism-category-chips button span { color: var(--dim); }
.mechanism-category-chips button:hover,
.mechanism-category-chips button.is-active { border-color: color-mix(in srgb, var(--brand) 55%, transparent); background: color-mix(in srgb, var(--brand) 6%, transparent); color: var(--ink); }

.mechanism-family-result { margin: .65rem 0 .45rem; color: var(--dim); font: .75rem var(--mono); }
.mechanisms-family-index { max-height: calc(100svh - 285px); padding-right: .2rem; overflow-y: auto; overscroll-behavior: contain; scrollbar-width: thin; scrollbar-color: rgba(238, 240, 243, 0.08) transparent; }
.mechanisms-family-index article { margin: 0 0 .28rem; }
.mechanisms-family-index article[hidden] { display: none; }
.mechanisms-family-index button { display: grid; grid-template-columns: 2rem 1fr; width: 100%; min-height: 59px; padding: .62rem .6rem; border: 1px solid transparent; border-radius: 6px; background: transparent; color: var(--ink); text-align: left; }
.mechanisms-family-index button > span { grid-row: 1 / span 2; color: var(--dim); font: 700 .75rem/1.5 var(--mono); }
.mechanisms-family-index button strong { min-width: 0; overflow: hidden; font-size: .76rem; font-weight: 680; line-height: 1.35; text-overflow: ellipsis; white-space: nowrap; }
.mechanisms-family-index button small { min-width: 0; margin-top: .14rem; overflow: hidden; color: var(--dim); font-size: .75rem; line-height: 1.3; text-overflow: ellipsis; white-space: nowrap; }
.mechanisms-family-index button:hover { background: rgba(238, 240, 243, 0.027); }
.mechanisms-family-index button[aria-current="true"] { border-color: color-mix(in srgb, var(--cyan) 25%, transparent); background: linear-gradient(90deg, color-mix(in srgb, var(--cyan) 7%, transparent), color-mix(in srgb, var(--brand) 4%, transparent)); box-shadow: inset 3px 0 var(--cyan); }
.mechanisms-family-index button[aria-current="true"] > span { color: var(--cyan); }
.mechanisms-family-index details { display: none; }
.mechanism-empty { padding: 1rem; color: var(--muted); font-size: .78rem; }

.mechanism-stage { position: relative; min-height: 760px; overflow: hidden; scroll-margin-top: 86px; background: linear-gradient(155deg, rgba(238, 240, 243, 0.023), transparent 22%), var(--mechanism-frost-strong); }
.mechanism-stage-state { position: absolute; inset: 0; z-index: 9; display: grid; place-content: center; justify-items: center; gap: .75rem; padding: 2rem; background: rgba(30, 33, 36, 0.94); color: var(--muted); font: .75rem var(--mono); text-align: center; }
.mechanism-stage-state span { width: 34px; height: 34px; border: 2px solid rgba(238, 240, 243, 0.143); border-top-color: var(--brand); border-radius: 50%; animation: mechanism-spin .8s linear infinite; }
.mechanism-stage-state.is-error span { border: 0; border-radius: 0; animation: none; }
.mechanism-stage-state[hidden] { display: none; }
@keyframes mechanism-spin { to { transform: rotate(1turn); } }

.mechanism-stage-header { display: flex; align-items: start; justify-content: space-between; gap: 1.5rem; padding: 17px; border-bottom: 1px solid var(--mechanism-line); }
.mechanism-stage-kicker { color: var(--cyan); font: 700 .75rem/1.4 var(--mono);   }
.mechanism-stage-header h3 { max-width: 790px; margin: .4rem 0 .2rem; font-size: 20px; font-weight: 500; line-height: 1.05; letter-spacing: -.01em; }
.mechanism-stage-header p { margin: 0; color: var(--muted); font-size: .82rem; }
.mechanism-representation { display: inline-flex; min-height: 32px; align-items: center; padding: .38rem .55rem; margin-top: .65rem; border: 1px solid color-mix(in srgb, var(--cyan) 28%, transparent); border-radius: 5px; background: color-mix(in srgb, var(--cyan) 4%, transparent); color: var(--cyan); font: 700 .75rem/1.25 var(--mono); }
.mechanism-stage-tools { display: grid; min-width: max-content; justify-items: end; gap: .55rem; }
.mechanism-stage-tools button { min-height: 36px; padding: .4rem .7rem; border: 1px solid var(--mechanism-line); border-radius: 6px; background: rgba(238, 240, 243, 0.02); color: var(--ink-soft); font: 700 .75rem var(--mono);  }
.mechanism-stage-tools button:hover { border-color: var(--brand); }
.mechanism-stage-tools span { color: var(--dim); font: .75rem var(--mono); }

.mechanism-reaction-plate { display: flex; min-height: 180px; align-items: stretch; gap: .55rem; padding: clamp(.8rem, 2vw, 1.3rem); overflow-x: auto; border-bottom: 1px solid var(--mechanism-line); background: rgba(238, 240, 243, 0.011); scrollbar-width: thin; }
.mechanism-reaction-loading { display: grid; width: 100%; place-items: center; color: var(--dim); font: .75rem var(--mono); }
.mechanism-reaction-side { display: flex; min-width: 0; flex: 1 1 0; align-items: stretch; gap: .45rem; }
.mechanism-reaction-arrow { display: grid; min-width: 68px; place-items: center; color: var(--brand-bright); }
.mechanism-reaction-arrow span { font-size: 18px; line-height: 1; }
.mechanism-reaction-arrow small { color: var(--dim); font: .75rem var(--mono);  }
.mechanism-structure-card { position: relative; display: grid; min-width: 110px; flex: 1 1 0; grid-template-rows: minmax(88px, 1fr) auto; align-items: center; padding: .52rem; margin: 0; overflow: hidden; border: 1px solid rgba(238,240,243,.14); border-radius: 6px; background: var(--mechanism-paper-2); color: var(--mechanism-paper-ink); box-shadow: 0 10px 24px rgba(0, 0, 0, 0.101); }
.mechanism-structure-card img { width: 100%; height: 88px; object-fit: contain; }
.mechanism-structure-card.is-fallback { place-items: center; grid-template-rows: 1fr auto; }
.mechanism-structure-formula { color: var(--mechanism-paper-ink); font: 650 .78rem/1.45 var(--mono); text-align: center; overflow-wrap: anywhere; }
.mechanism-structure-card figcaption { min-width: 0; padding-top: .42rem; border-top: 1px solid rgba(238,240,243,.1); }
.mechanism-structure-card strong { display: block; overflow: hidden; font-size: .75rem; line-height: 1.2; text-overflow: ellipsis; white-space: nowrap; }
.mechanism-structure-card small { display: block; margin-top: .1rem; color: var(--mechanism-paper-muted); font: .75rem var(--mono); }
.mechanism-helper-list { display: flex; min-width: 118px; flex: 0 0 118px; flex-direction: column; justify-content: center; gap: .32rem; padding: .6rem; border: 1px dashed color-mix(in srgb, var(--cyan) 25%, transparent); border-radius: 6px; color: var(--ink-soft); background: color-mix(in srgb, var(--cyan) 4%, transparent); }
.mechanism-helper-list span { color: var(--cyan); font: 700 .75rem var(--mono);   }
.mechanism-helper-list strong { font-size: .75rem; font-weight: 560; line-height: 1.3; }

.mechanism-step-navigation { border-bottom: 1px solid var(--mechanism-line); }
.mechanism-step-controls { display: flex; gap: .35rem; padding: .75rem clamp(.75rem, 2vw, 1.3rem); overflow-x: auto; scrollbar-width: thin; }
.mechanism-step-controls button { display: grid; min-width: 96px; min-height: 48px; flex: 1 0 0; grid-template-columns: auto 1fr; align-items: center; gap: .5rem; padding: .42rem .6rem; border: 1px solid var(--mechanism-line); border-radius: 6px; background: transparent; color: var(--muted); text-align: left; }
.mechanism-step-controls button > span { color: var(--dim); font: 700 .75rem var(--mono); }
.mechanism-step-controls button small { overflow: hidden; font: 650 .75rem var(--mono); text-overflow: ellipsis; white-space: nowrap; }
.mechanism-step-controls button:hover { background: rgba(238, 240, 243, 0.02); }
.mechanism-step-controls button[aria-selected="true"] { border-color: color-mix(in srgb, var(--brand) 50%, transparent); background: color-mix(in srgb, var(--brand) 6%, transparent); color: var(--ink); box-shadow: inset 0 -2px var(--brand); }
.mechanism-step-controls button[aria-selected="true"] > span { color: var(--brand-bright); }
.mechanism-step-jump { display: grid; grid-template-columns: 44px minmax(0,1fr) 44px; align-items: center; gap: .55rem; padding: 0 clamp(.75rem,2vw,1.3rem) .75rem; }
.mechanism-step-jump button { width: 44px; height: 44px; border: 1px solid var(--mechanism-line); border-radius: 6px; background: rgba(238, 240, 243, 0.02); color: var(--ink); font-size: 1rem; }
.mechanism-step-jump button:disabled { opacity: .35; }
.mechanism-step-jump p { margin: 0; overflow-wrap: anywhere; color: var(--ink-soft); font-size: .82rem; text-align: center; }

.mechanism-scene-stack { min-height: 420px; padding: clamp(.7rem, 2vw, 1.25rem); background: rgba(238, 240, 243, 0.02); }
[data-mechanism-panel] { position: relative; min-height: 390px; overflow: hidden; border: 1px solid rgba(238,240,243,.15); border-radius: 6px; background: var(--mechanism-paper); color: var(--mechanism-paper-ink); box-shadow: inset 0 1px rgba(0, 0, 0, 0.312), 0 16px 46px rgba(0, 0, 0, 0.14); }
[data-mechanism-panel][hidden] { display: none; }
[data-mechanism-panel] > svg { display: block; width: 100%; min-height: 390px; height: auto; }
[data-mechanism-panel] > svg > text { fill: var(--mechanism-paper-muted); font: 650 15px var(--mono); }
.mechanism-scene-bond { stroke: #b9bfc6; stroke-width: 2.15; stroke-linecap: round; vector-effect: non-scaling-stroke; }
.mechanism-scene-bond.is-aromatic { stroke-dasharray: 5 4; }
.mechanism-scene-wedge { fill: #302d36; }
.mechanism-scene-wedge-hatch { stroke: var(--line); stroke-width: 1.3; }
.mechanism-scene-atom { fill: #e6e9ec; font: 700 14px/1 var(--mono); paint-order: stroke; stroke: var(--mechanism-paper); stroke-width: 4px; stroke-linejoin: round; }
.mechanism-scene-atom.element-O { fill: var(--brand); }
.mechanism-scene-atom.element-N { fill: var(--bio); }
.mechanism-scene-atom.element-S { fill: var(--amber); }
.mechanism-scene-atom.element-P { fill: var(--amber); }
.mechanism-scene-atom.element-F,
.mechanism-scene-atom.element-Cl,
.mechanism-scene-atom.element-Br,
.mechanism-scene-atom.element-I { fill: var(--bio); }
.mechanism-scene-atom.element-Zn,
.mechanism-scene-atom.element-Mg,
.mechanism-scene-atom.element-Fe { fill: var(--muted); }
.mechanism-scene-label { fill: #4f4955; font: 650 11px/1 var(--mono); paint-order: stroke; stroke: var(--mechanism-paper); stroke-width: 4px; }
.mechanism-scene-charge { fill: #46404b; font: 700 9px var(--mono); }
.mechanism-scene-lone-pair { fill: #38323d; }
.mechanism-electron-flow { fill: none; stroke: var(--mechanism-red); stroke-width: 2.5; stroke-linecap: round; vector-effect: non-scaling-stroke; filter: drop-shadow(0 1px 1px color-mix(in srgb, var(--brand) 9%, transparent)); }
.mechanism-electron-flow[data-electrons="1"] { stroke-dasharray: 4 4; }
.mechanism-electron-head { fill: var(--mechanism-red); }
.mechanism-scene-caption { fill: var(--muted); font: 650 10px var(--mono);  }

.mechanism-process-frame { display: grid; min-height: 390px; grid-template-rows: auto 1fr auto; padding: 17px; background: linear-gradient(135deg, rgba(238, 240, 243, 0.102), rgba(238, 240, 243, 0.102)); }
.mechanism-process-label { color: var(--muted); font: 700 .75rem var(--mono);   }
.mechanism-process-track { display: flex; align-items: center; justify-content: center; gap: clamp(.5rem, 2vw, 1.25rem); padding-block: 1.2rem; }
.mechanism-process-entity { display: grid; width: min(155px, 30%); min-height: 145px; place-items: center; padding: .65rem; margin: 0; border: 1px solid rgba(238,240,243,.13); border-radius: 6px; background: rgba(238, 240, 243, 0.102); box-shadow: 0 10px 30px rgba(0, 0, 0, 0.216); text-align: center; }
.mechanism-process-entity img { width: 100%; height: 94px; object-fit: contain; }
.mechanism-process-entity span { color: #2c2831; font: 650 .75rem/1.25 var(--sans); }
.mechanism-process-arrow { display: grid; min-width: 45px; place-items: center; color: var(--mechanism-red); font-size: 1.75rem; }
.mechanism-process-note { margin: 0; color: #58515d; font-size: .78rem; text-align: center; }

.mechanism-narration { display: grid; grid-template-columns: minmax(90px, .16fr) 1fr; gap: 1.2rem; padding: 1.2rem 17px; border-top: 1px solid var(--mechanism-line); }
.mechanism-narration span { color: var(--brand-bright); font: 700 .75rem var(--mono);   }
.mechanism-narration p { max-width: 850px; margin: 0; color: var(--ink-soft); font-size: .9rem; }
.mechanism-narration button { grid-column: 2; min-height: 40px; justify-self: start; padding: .45rem .65rem; border: 1px solid var(--mechanism-line); border-radius: 6px; background: transparent; color: var(--cyan); font: 700 .75rem var(--mono); }
.mechanism-narration button[aria-pressed="true"] { border-color: var(--brand); background: color-mix(in srgb, var(--brand) 5%, transparent); color: var(--brand-bright); }
[data-mechanism-panel].is-move-highlighted .mechanism-electron-flow { stroke-width: 4; filter: drop-shadow(0 0 4px color-mix(in srgb, var(--brand) 27%, transparent)); }
[data-mechanism-panel] .is-move-atom { font-size: 17px; filter: drop-shadow(0 0 3px color-mix(in srgb, var(--brand) 21%, transparent)); }
.mechanism-deep-detail { margin: 0 17px 1rem; border: 1px solid var(--mechanism-line); border-radius: 6px; background: rgba(238, 240, 243, 0.014); }
.mechanism-deep-detail summary { min-height: 44px; padding: .75rem .9rem; color: var(--ink-soft); font: 700 .75rem var(--mono);   }
.mechanism-deep-detail[open] summary { border-bottom: 1px solid var(--mechanism-line); }
.mechanism-deep-detail > div { padding: 1rem; color: var(--muted); font-size: .8rem; }
.mechanism-deep-detail dl { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: .7rem; margin: 0; }
.mechanism-deep-detail dl div { padding: .7rem; border: 1px solid var(--mechanism-line); border-radius: 6px; }
.mechanism-deep-detail dt { color: var(--dim); font: 700 .75rem var(--mono);  }
.mechanism-deep-detail dd { margin: .25rem 0 0; color: var(--ink-soft); }
.mechanism-source-step-list { padding-left: 1.2rem; }
.mechanism-source-step-list li { margin-bottom: .35rem; }
.mechanism-misconception { display: grid; grid-template-columns: minmax(130px,.22fr) 1fr; gap: 1rem; padding: 1rem 17px 1.3rem; border-top: 1px solid var(--mechanism-line); background: color-mix(in srgb, var(--amber) 4%, transparent); }
.mechanism-misconception span { color: var(--amber); font: 700 .75rem var(--mono);   }
.mechanism-misconception p { margin: 0; color: var(--muted); font-size: .8rem; }

.mechanism-evidence-inspector { position: sticky; top: calc(var(--fg-sticky-top) + 12px); max-height: calc(100svh - var(--fg-sticky-top) - 24px); overflow-y: auto; }
.mechanism-evidence-sticky { padding: 1.1rem; }
.mechanism-evidence-sticky > h3 { margin: .5rem 0 1rem; font-size: 1.1rem; font-weight: 540; letter-spacing: -.025em; }
.mechanism-evidence-sticky > div > p { margin: 0 0 1rem; color: var(--muted); font-size: .76rem; }
.mechanism-scope-badge { display: inline-flex; min-height: 28px; align-items: center; padding: .3rem .55rem; margin-bottom: .65rem; border: 1px solid color-mix(in srgb, var(--cyan) 30%, transparent); border-radius: 5px; color: var(--cyan); background: color-mix(in srgb, var(--cyan) 4%, transparent); font: 700 .75rem var(--mono);  }
.mechanism-evidence-sticky details { border-top: 1px solid var(--mechanism-line); }
.mechanism-evidence-sticky summary { min-height: 44px; padding: .8rem 0; color: var(--ink-soft); font: 700 .75rem var(--mono);   }
.mechanism-evidence-sticky details > div { padding: 0 0 1rem; }
.mechanism-identifier-list { display: flex; flex-wrap: wrap; gap: .35rem; }
.mechanism-identifier-list a,
.mechanism-identifier-list code { display: inline-flex; min-height: 29px; align-items: center; padding: .3rem .45rem; border: 1px solid var(--mechanism-line); border-radius: 6px; color: var(--ink-soft); background: rgba(238, 240, 243, 0.015); font: .75rem var(--mono); text-decoration: none; overflow-wrap: anywhere; }
.mechanism-source-list { display: grid; gap: .38rem; }
.mechanism-source-list a { display: flex; min-height: 38px; align-items: center; justify-content: space-between; gap: .5rem; padding: .5rem .6rem; border: 1px solid var(--mechanism-line); border-radius: 6px; color: var(--ink-soft); font-size: .75rem; text-decoration: none; }
.mechanism-source-list a::after { content: "↗"; color: var(--brand-bright); }
.mechanism-provenance-copy { color: var(--muted); font-size: .75rem; }
.mechanism-provenance-copy strong { display: block; margin-bottom: .25rem; color: var(--ink-soft); }

.mechanisms-mcat,
.mechanisms-next {
  display: grid;
  grid-template-columns: minmax(260px, .75fr) minmax(0, 1fr);
  align-items: center;
  gap: 24px;
  width: min(100%, 1440px);
  padding: 24px 24px;
  margin: auto;
  border-top: 1px solid var(--mechanism-line);
}

.mechanisms-mcat h2,
.mechanisms-next h2 { margin: .65rem 0 0; font-size: 24px; font-weight: 500; line-height: 1.02; letter-spacing: -.01em; }
.mechanisms-mcat > p,
.mechanisms-next p { max-width: 740px; margin: 0; color: var(--muted); }
.mechanisms-mcat-tags { grid-column: 2; display: flex; flex-wrap: wrap; gap: .45rem; }
.mechanisms-mcat-tags span { padding: .42rem .62rem; border: 1px solid var(--mechanism-line); border-radius: 5px; color: var(--ink-soft); font: .75rem var(--mono); }
.mechanisms-next-actions { display: flex; flex-wrap: wrap; gap: .65rem; }

@media (max-width: 1280px) {
  .mechanism-workspace-grid { grid-template-columns: minmax(235px, 270px) minmax(0, 1fr); }
  .mechanism-evidence-inspector { position: static; grid-column: 2; max-height: none; }
  .mechanism-evidence-sticky { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 0 1rem; }
  .mechanism-evidence-sticky > .eyebrow,
  .mechanism-evidence-sticky > h3,
  .mechanism-evidence-sticky > [data-evidence-summary] { grid-column: 1 / -1; }
}

@media (max-width: 980px) {
  .mechanisms-hero { grid-template-columns: 1fr; min-height: 0; }
  .mechanisms-hero-copy { max-width: 850px; }
  .mechanisms-hero-figure { width: min(100%, 660px); margin-inline: auto; }
  .mechanism-workspace-intro { grid-template-columns: 1fr; gap: 1.2rem; }
  .mechanism-workspace-grid { grid-template-columns: minmax(210px, 245px) minmax(0,1fr); }
  .mechanism-evidence-sticky { grid-template-columns: 1fr; }
}

@media (max-width: 760px) {
  .mechanisms-hero { padding-top: .8rem; padding-bottom: .7rem; gap: 0; }
  .mechanisms-hero-copy h1 { margin: .5rem 0 .6rem; font-size: 20px; }
  .mechanisms-hero-copy > p { display: -webkit-box; overflow: hidden; font-size: .88rem; line-height: 1.42; -webkit-box-orient: vertical; -webkit-line-clamp: 2; }
  .mechanisms-hero-actions { margin-top: .65rem; }
  .mechanisms-hero-actions .button:not(.primary) { display: none; }
  .mechanisms-hero-register { grid-template-columns: repeat(3, minmax(0,1fr)); margin-top: .7rem; }
  .mechanisms-hero-register div { padding: .4rem .25rem; border-right: 1px solid var(--mechanism-line); border-bottom: 0; }
  .mechanisms-hero-register div:first-child { padding-left: 0; }
  .mechanisms-hero-register div:last-child { border-right: 0; }
  .mechanisms-hero-register dt { overflow-wrap: anywhere; font-size: .75rem;  }
  .mechanisms-hero-register dd { font-size: .75rem; }
  .mechanisms-hero-figure { display: none; }
  .mechanism-workspace { width: min(calc(100% - 1rem), 1580px); }
  .mechanism-workspace-intro { gap: .45rem; padding: .9rem .5rem .65rem; }
  .mechanism-workspace-intro h2 { font-size: 17px; }
  .mechanism-workspace-intro > p { display: none; }
  .mechanism-mobile-picker { margin-bottom: .5rem; }
  .mechanism-mobile-picker select { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .mechanism-mobile-picker { display: grid; }
  .mechanism-workspace-grid { grid-template-columns: 1fr; }
  .mechanism-family-rail { display: none; }
  .mechanism-evidence-inspector { grid-column: 1; }
  .mechanism-stage { min-height: 0; border-radius: 6px; }
  .mechanism-stage-header { display: grid; }
  .mechanism-stage-tools { display: flex; min-width: 0; align-items: center; justify-content: space-between; justify-items: initial; }
  .mechanism-reaction-plate { display: grid; min-height: 0; grid-template-columns: 1fr; overflow: visible; padding: .75rem; }
  .mechanism-reaction-side { display: grid; width: 100%; min-width: 0; grid-template-columns: repeat(auto-fit,minmax(120px,1fr)); }
  .mechanism-reaction-arrow { min-width: 0; min-height: 48px; }
  .mechanism-reaction-arrow span { font-size: 1.35rem; transform: rotate(90deg); }
  .mechanism-reaction-arrow small { display: block; font-size: .75rem; }
  .mechanism-structure-card { min-width: 0; min-height: 145px; grid-template-rows: minmax(82px, 1fr) auto; padding: .5rem; }
  .mechanism-structure-card img { height: 82px; }
  .mechanism-structure-card strong { overflow: visible; font-size: .78rem; line-height: 1.3; overflow-wrap: anywhere; text-overflow: clip; white-space: normal; }
  .mechanism-structure-card small { font-size: .75rem; line-height: 1.3; overflow-wrap: anywhere; }
  .mechanism-process-entity .mechanism-structure-formula { max-width: 100%; font-size: .75rem; line-height: 1.3; }
  .mechanism-process-entity strong { display: block; overflow: visible; line-height: 1.25; white-space: normal; }
  .mechanism-helper-list { min-width: 0; min-height: 48px; flex-basis: auto; flex-direction: row; flex-wrap: wrap; align-items: center; justify-content: flex-start; }
  .mechanism-helper-list strong { padding-left: .4rem; border-left: 1px solid var(--mechanism-line); }
  .mechanism-step-controls { display: grid; grid-template-columns: repeat(var(--mechanism-step-count,5),minmax(40px,1fr)); gap: .25rem; overflow: visible; padding: .65rem .55rem; }
  .mechanism-step-controls button { min-width: 0; min-height: 44px; grid-template-columns: 1fr; justify-items: center; padding: .35rem; }
  .mechanism-step-controls button small { display: none; }
  .mechanism-step-controls button > span { font-size: .75rem; }
  .mechanism-step-jump { padding: 0 .55rem .65rem; }
  .mechanism-step-jump p { font-size: .85rem; line-height: 1.4; }
  .mechanism-scene-stack { min-height: 0; padding: .5rem; }
  [data-mechanism-panel],
  .mechanism-process-frame { min-height: 280px; }
  [data-mechanism-panel] > svg { min-height: 0; }
  .mechanism-narration,
  .mechanism-misconception { grid-template-columns: 1fr; gap: .45rem; }
  .mechanism-narration button { grid-column: 1; min-height: 44px; }
  .mechanism-deep-detail dl { grid-template-columns: 1fr; }
  .mechanisms-mcat,
  .mechanisms-next { grid-template-columns: 1fr; gap: 1.25rem; }
  .mechanisms-mcat-tags { grid-column: 1; }
}

@media (max-width: 390px) {
  .mechanisms-hero { padding-inline: 1rem; }
  .mechanisms-hero-actions .button { width: 100%; }
  .mechanisms-hero-figure { margin-inline: -.3rem; width: calc(100% + .6rem); }
  .mechanism-stage-header h3 { font-size: 1.55rem; }
  .mechanism-reaction-side { min-width: 0; }
  .mechanism-structure-card { min-width: 0; }
  [data-mechanism-panel],
  .mechanism-process-frame { min-height: 270px; }
  .mechanism-process-track { gap: .3rem; }
  .mechanism-process-entity { width: min(130px, 36%); min-height: 125px; }
  .mechanism-process-entity img { height: 72px; }
  .mechanism-process-arrow { min-width: 28px; }
}

@media (prefers-reduced-motion: reduce) {
  .mechanism-stage-state span { animation-duration: 1.8s; }
  .mechanisms-family-index { scroll-behavior: auto; }
}

@media (forced-colors: active) {
  .mechanism-family-rail,
  .mechanism-evidence-inspector,
  .mechanism-stage,
  [data-mechanism-panel] { border: 1px solid CanvasText; }
  .mechanisms-family-index button[aria-current="true"] { outline: 2px solid Highlight; }
  .mechanism-electron-flow { stroke: LinkText; }
}

@media print {
  .mechanism-family-rail,
  .mechanism-mobile-picker,
  .mechanism-stage-tools,
  .mechanism-step-controls,
  .mechanism-evidence-inspector,
  .mechanisms-hero-actions { display: none !important; }
  .mechanisms-hero { min-height: 0; grid-template-columns: 1fr; }
  .mechanism-workspace-grid { display: block; }
  .mechanism-stage { border: 1px solid #888; background: #fff; color: #111; box-shadow: none; }
  [data-mechanism-panel] { break-inside: avoid; }
}