:root {
  color-scheme: light;
  --navy: #023347;
  --ink: #17262d;
  --muted: #566570;
  --teal: #087985;
  --mist: #e8f7f7;
  --line: #cbdfe2;
  --paper: #f7fafa;
  --white: #fff;
  --mark: #0b93a2;
  --amber: #b78212;
  --amber-ink: #75530c;
  --amber-soft: #fff6df;
  --amber-line: #ecd39a;
  --wire: #9fb3b9;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.55;
  color: var(--ink);
  background: var(--paper);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: var(--section-nav-height, 104px); }
body { margin: 0; background: var(--paper); overflow-wrap: anywhere; }
button { font: inherit; cursor: pointer; }
button, [tabindex] { -webkit-tap-highlight-color: transparent; }
[hidden] { display: none !important; }
h1, h2, h3, p, figure, ul, ol { margin: 0; }
ul, ol { padding: 0; list-style: none; }
svg { flex: none; }

.skip { position: fixed; top: -80px; left: 10px; z-index: 100; padding: 10px 13px; border-radius: 8px; background: var(--white); color: var(--navy); }
.skip:focus { top: 10px; }
:focus-visible { outline: 3px solid #b78212; outline-offset: 3px; }
#main:focus { outline: none; }
.sr-only { position: absolute !important; width: 1px !important; height: 1px !important; padding: 0 !important; margin: -1px !important; overflow: hidden !important; clip: rect(0, 0, 0, 0) !important; white-space: nowrap !important; border: 0 !important; }

.story-shell { width: min(100%, 760px); margin: 0 auto; }
.brand-header { min-height: 62px; display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 14px 22px; border-bottom: 1px solid var(--line); background: #ffffffd9; }
.brand-header img { display: block; width: 140px; height: auto; }
.brand-header span { max-width: 170px; color: var(--muted); font-size: .7rem; line-height: 1.35; text-align: right; }

.section-nav { position: sticky; top: 0; z-index: 5; display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 10px; padding: 10px 22px; border-bottom: 1px solid var(--line); background: #f7fafaf7; }
.section-nav label { color: var(--navy); font-size: .85rem; font-weight: 650; }
.section-nav select { min-width: 0; max-width: 64%; min-height: 44px; padding: 8px; border: 1px solid var(--line); border-radius: 7px; background: var(--white); color: var(--navy); font: inherit; font-size: .85rem; }

main { padding: 0 22px 54px; }
.intro { padding: 34px 0 26px; }
.eyebrow { color: var(--teal); font-size: .72rem; font-weight: 750; letter-spacing: .105em; text-transform: uppercase; }
.intro h1 { max-width: 620px; margin: 10px 0 14px; color: var(--navy); font-size: clamp(2rem, 8.8vw, 3.65rem); font-weight: 650; letter-spacing: -.052em; line-height: 1.03; }
.honesty { display: inline-block; padding: 5px 10px; border: 1px solid var(--line); border-radius: 999px; background: var(--white); color: var(--muted); font-size: .72rem; font-weight: 650; letter-spacing: .03em; }
.honesty.foot { display: block; margin-top: 14px; border: 0; background: none; text-align: center; }

section { padding: 30px 0 40px; border-top: 1px solid var(--line); }
.section-heading { display: grid; grid-template-columns: 34px minmax(0, 1fr); gap: 12px; align-items: start; margin-bottom: 20px; }
.section-number { display: grid; place-items: center; width: 32px; height: 32px; border: 1px solid var(--line); border-radius: 50%; color: var(--teal); font-size: .7rem; font-weight: 750; }
.section-heading h2 { margin-top: 5px; color: var(--navy); font-size: clamp(1.65rem, 6.5vw, 2.4rem); font-weight: 650; letter-spacing: -.04em; line-height: 1.1; }
.caption { margin-top: 12px; color: var(--teal); font-size: .9rem; font-weight: 600; min-height: 1.4em; }
.ghost { min-height: 44px; padding: 9px 14px; border: 1px solid var(--line); border-radius: 9px; background: var(--white); color: var(--navy); font-size: .85rem; font-weight: 650; }
.ghost:hover { border-color: var(--teal); color: var(--teal); }

/* shared chips and marks */
.chip { display: inline-flex; align-items: center; gap: 5px; min-height: 28px; padding: 3px 9px; border: 1px solid var(--line); border-radius: 8px; background: var(--white); color: var(--navy); font-size: .78rem; font-weight: 600; line-height: 1.2; }
.chip.slash { border-color: #9dcdd1; background: var(--mist); color: var(--teal); font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .76rem; }
.chip em { padding: 1px 5px; border-radius: 4px; background: var(--white); color: var(--muted); font-size: .58rem; font-style: normal; font-weight: 750; letter-spacing: .06em; }
.chip.file { border-style: dashed; background: var(--paper); }
.chip.file.drag { cursor: grab; text-decoration: none; border-color: var(--teal); color: var(--teal); }
.chip.file.drag::before { content: "⤓"; font-weight: 800; }
.chip.file.drag:hover { background: var(--mist); }
.chip.file.drag.is-dragging { cursor: grabbing; opacity: .6; }
.chip.agent { border-color: var(--navy); background: var(--navy); color: var(--white); }
.chip.model { border-color: #9fb3b9; border-radius: 999px; }
.chip.tool { border-color: #c9c4f2; background: #f1efff; color: #4c42b7; }
.mark { display: inline-grid; place-items: center; flex: none; width: 22px; height: 22px; border-radius: 50%; background: var(--navy); color: var(--white); font-size: .68rem; font-weight: 800; }

/* run 2 step 5 · one shared thread, segments split by a surface gap */
.collab { padding: 12px 14px; border: 1px solid var(--line); border-radius: 12px; background: var(--paper); }
.timeline { display: flex; gap: 2px; }
.seg { flex: 1 1 0; display: grid; gap: 6px; align-content: start; justify-items: center; padding: 0 4px; color: var(--ink); font-size: .74rem; font-weight: 650; text-align: center; line-height: 1.2; }
.seg:nth-child(2) { flex-basis: 24%; flex-grow: 0; }
.bar { display: block; width: 100%; height: 12px; background: var(--mark); }
.seg:first-child .bar { border-radius: 6px 0 0 6px; }
.seg:last-child .bar { border-radius: 0 6px 6px 0; }
.bar.is-paused { background: var(--amber); }
.seg em { padding: 1px 6px; border: 1px solid var(--amber-line); border-radius: 999px; background: var(--amber-soft); color: var(--amber-ink); font-size: .6rem; font-style: normal; font-weight: 750; letter-spacing: .06em; text-transform: uppercase; }

/* 04 · before and after */
.before-after { display: grid; gap: 14px; }
.panel { padding: 14px 14px 16px; border: 1px solid var(--line); border-radius: 16px; background: var(--white); }
.panel.is-after { border-color: #9dcdd1; background: #f3fbfb; }
.panel figcaption { margin-bottom: 8px; }
.panel-tag { display: inline-block; padding: 4px 10px; border-radius: 999px; background: #eef4f5; color: var(--muted); font-size: .7rem; font-weight: 750; letter-spacing: .08em; text-transform: uppercase; }
.is-after .panel-tag { background: var(--navy); color: var(--white); }
.panel svg { display: block; width: 100%; height: auto; font-family: inherit; }
.panel text { font-size: 10px; font-weight: 650; fill: var(--navy); text-anchor: middle; }
.panel .foot { font-size: 8.5px; font-weight: 650; fill: var(--muted); }
.panel .is-warn { fill: var(--amber-ink); }
.node rect { fill: var(--white); stroke: var(--line); stroke-width: 1; }
.tool rect { fill: #eef4f5; stroke: #dbe6e8; }
.tool .is-card { fill: var(--amber-soft); stroke: var(--amber-line); }
.tool .is-none { fill: none; stroke: var(--amber); stroke-dasharray: 3 3; }
.wire path { fill: none; stroke: var(--wire); stroke-width: 1.5; stroke-linecap: round; }
.wire .is-cut { stroke: var(--amber); stroke-dasharray: 3 4; }
.wire.is-on path { stroke: var(--mark); stroke-width: 2; }
.layer rect { fill: var(--navy); }
.layer text { font-size: 10.5px; fill: var(--white); }
.provider circle { fill: var(--white); stroke: var(--mark); stroke-width: 2; }
.provider .mark { font-size: 10px; fill: var(--navy); }
.provider .foot { font-size: 8px; }
.counts { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; margin-top: 10px; padding-top: 12px; border-top: 1px solid var(--line); }
.counts li { text-align: center; }
.counts strong { display: block; color: var(--amber-ink); font-size: 1.7rem; font-weight: 700; letter-spacing: -.04em; line-height: 1; }
.is-after .counts strong { color: var(--teal); }
.counts span { display: block; margin-top: 3px; color: var(--muted); font-size: .68rem; font-weight: 650; letter-spacing: .05em; text-transform: uppercase; }

.shelf { display: grid; gap: 14px; }
.stat-strip { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; }
.stat-strip li { padding: 14px 12px; border: 1px solid var(--line); border-radius: 14px; background: var(--white); text-align: center; }
.stat-strip strong { display: block; color: var(--navy); font-size: clamp(2rem, 8vw, 2.9rem); font-weight: 700; letter-spacing: -.05em; line-height: 1; }
.stat-strip span { display: block; margin-top: 4px; color: var(--muted); font-size: .78rem; font-weight: 650; letter-spacing: .05em; text-transform: uppercase; }
.stat-strip .is-one { border-color: var(--teal); background: var(--navy); }
.stat-strip .is-one strong { color: var(--white); }
.stat-strip .is-one span { color: #bfe8ec; }

.picker { display: grid; grid-template-columns: minmax(0, 1fr); overflow: hidden; border: 1px solid var(--line); border-radius: 14px; background: var(--white); }
.picker-rail { padding: 14px 12px; border-bottom: 1px solid var(--line); background: var(--paper); }
.picker-title { margin: 0 6px 10px; color: var(--navy); font-size: .8rem; font-weight: 700; letter-spacing: .04em; text-transform: uppercase; }
#provider-tabs { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
#provider-tabs button { display: grid; grid-template-columns: 22px minmax(0, 1fr) auto; grid-template-rows: auto 6px; column-gap: 8px; row-gap: 5px; align-items: center; min-height: 48px; padding: 6px 10px 7px 8px; border: 1px solid transparent; border-radius: 10px; background: transparent; color: var(--navy); font-size: .85rem; font-weight: 600; text-align: left; }
#provider-tabs button:hover { background: var(--white); border-color: var(--line); }
#provider-tabs button[aria-selected="true"] { border-color: #9dcdd1; background: var(--mist); font-weight: 700; }
#provider-tabs .mark { grid-row: 1 / 3; }
.tab-n { color: var(--muted); font-size: .72rem; font-weight: 700; font-variant-numeric: tabular-nums; }
/* the rail doubles as a bar chart of models per provider: one hue, data-end rounded, baseline square */
.tab-bar { grid-column: 2 / 4; height: 6px; border-radius: 0 3px 3px 0; background: var(--mark); }
.picker-panel { padding: 14px 16px 16px; }
.picker-panel-title { margin-bottom: 8px; padding: 8px 12px; border-radius: 9px; background: var(--paper); color: var(--navy); font-size: .9rem; font-weight: 700; }
.model-rows li { display: flex; align-items: center; justify-content: space-between; gap: 10px; min-height: 48px; padding: 8px 12px; border-bottom: 1px solid #edf3f4; animation: rise .28s ease-out both; }
.model-rows li:last-child { border-bottom: 0; }
.model-rows strong { display: block; color: var(--navy); font-size: .92rem; font-weight: 650; }
.row-sub { display: block; color: var(--muted); font-size: .74rem; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }
.hosts { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 4px; }
.host { padding: 2px 8px; border-radius: 999px; background: #eef4f5; color: var(--navy); font-size: .66rem; font-weight: 650; white-space: nowrap; }

.key { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 16px; }

.skill-flow { display: grid; gap: 10px; align-items: stretch; margin-bottom: 12px; padding: 16px; border: 1px solid var(--line); border-radius: 16px; background: var(--white); }
.skill-flow .once-node { align-content: start; }
.skill-flow .once-arrow { width: 34px; }
.skill-flow code { padding: 1px 5px; border-radius: 5px; background: var(--mist); color: var(--teal); font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .92em; }
.skill-flow .once-tag { display: inline-grid; place-items: center; justify-self: center; width: 22px; height: 22px; border-radius: 50%; background: var(--teal); color: var(--white); font-size: .68rem; letter-spacing: 0; }
.skill-flow strong { color: var(--navy); font-size: .92rem; font-weight: 650; letter-spacing: -.01em; }
.skill-flow figcaption { grid-column: 1 / -1; margin-top: 4px; color: var(--teal); font-size: .84rem; font-weight: 650; text-align: center; }

.once-node { display: grid; gap: 2px; text-align: center; }
.once-node strong { color: var(--navy); font-size: 1.05rem; font-weight: 700; letter-spacing: -.02em; }
.once-tag { color: var(--muted); font-size: .68rem; font-weight: 750; letter-spacing: .08em; text-transform: uppercase; }
.once-node.is-cmd { justify-items: center; }
.once-arrow { width: 40px; height: 24px; color: var(--mark); justify-self: center; transform: rotate(90deg); }

/* 01-03 · the run sheet */
.steps { display: grid; gap: 12px; }
.step { display: grid; gap: 10px; padding: 16px; border: 1px solid var(--line); border-radius: 16px; background: var(--white); }
.step-head { display: flex; align-items: center; gap: 10px; }
.step-num { display: inline-grid; place-items: center; flex: none; width: 30px; height: 30px; border-radius: 50%; background: var(--teal); color: var(--white); font-size: .88rem; font-weight: 750; }
.step-head h3 { color: var(--navy); font-size: 1.12rem; font-weight: 700; letter-spacing: -.025em; line-height: 1.2; }
.step-row { display: grid; gap: 6px; }
.row-label { color: var(--teal); font-size: .66rem; font-weight: 750; letter-spacing: .09em; text-transform: uppercase; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chip.ui { border-color: #c7d6da; border-radius: 6px; background: var(--paper); color: var(--muted); font-weight: 650; }

.fields { display: grid; gap: 7px; }
.field { display: grid; gap: 5px; padding: 10px 12px; border: 1px solid var(--line); border-radius: 11px; background: var(--paper); }
.f-name { color: var(--navy); font-size: .74rem; font-weight: 750; letter-spacing: .04em; }
.f-val { color: var(--ink); font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .8rem; line-height: 1.4; }
.prompt { display: grid; gap: 8px; justify-items: start; padding: 12px 14px; border: 1px solid #9dcdd1; border-radius: 4px 14px 14px 14px; background: var(--mist); }
.prompt-text { color: var(--ink); font-size: .92rem; font-style: italic; line-height: 1.45; }
.copy { min-height: 44px; padding: 9px 14px; border: 1px solid var(--line); border-radius: 8px; background: var(--white); color: var(--muted); font-size: .75rem; font-weight: 650; letter-spacing: .05em; text-transform: uppercase; }
.copy:hover { border-color: var(--teal); color: var(--teal); }
.copy[data-done] { border-color: var(--teal); background: var(--mist); color: var(--teal); }

.reach-out { display: grid; gap: 10px; justify-items: start; padding: 14px; border: 1px solid var(--line); border-radius: 14px; background: var(--paper); }
.reach-out.is-deep { border-color: var(--amber-line); background: #fffcf4; }
.reach-out figcaption { color: var(--navy); font-size: .86rem; font-weight: 700; }
.ro-track { display: flex; flex-direction: column; gap: 8px; width: 100%; }
.ro-track > .t-arrow { align-self: center; }
.reach-out .t-return { width: 100%; }
.reach-out .t-return b { color: var(--navy); }
.ro-caption { margin-top: 0; }
.nested { margin: 4px 0 6px; padding: 14px; border: 1px solid var(--line); border-radius: 14px; background: var(--paper); }

.t-node { display: grid; align-content: start; gap: 5px; padding: 12px 14px; border: 1px solid var(--line); border-radius: 14px; background: var(--white); transition: background .3s, border-color .3s, box-shadow .3s; }
.t-node.is-core { border-color: var(--teal); border-width: 2px; background: var(--mist); }
.t-tag { color: var(--teal); font-size: .66rem; font-weight: 750; letter-spacing: .09em; text-transform: uppercase; }
.t-node strong { color: var(--navy); font-size: .95rem; font-weight: 700; line-height: 1.25; }
.scope { display: block; width: fit-content; padding: 3px 8px; border-radius: 999px; background: #eef4f5; color: var(--navy); font-size: .7rem; font-weight: 650; }
.entities code { display: inline-flex; align-items: center; gap: 5px; padding: 2px 7px; border-radius: 5px; background: var(--white); border: 1px solid #9dcdd1; color: var(--navy); font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .68rem; }
.entities code::before { content: ""; width: 7px; height: 7px; border-radius: 2px; background: var(--mark); }
.entities .k-counted { border-color: var(--amber-line); background: var(--amber-soft); color: var(--amber-ink); }
.entities .k-counted::before { border-radius: 50%; background: var(--amber); }
.entities .k-locked { border-style: dashed; border-color: #b3bfc4; background: transparent; color: var(--muted); text-decoration: line-through; }
.entities .k-locked::before { background: none; border: 1px solid #a9b5ba; }
.reach-band { margin-top: 10px; padding: 14px 16px; border: 1px solid var(--line); border-radius: 14px; background: var(--white); }
.reach { margin-bottom: 10px; color: var(--navy); font-size: .95rem; font-weight: 700; }
.entities { display: flex; flex-wrap: wrap; gap: 5px; }
.entity-key { display: flex; flex-wrap: wrap; gap: 6px 16px; margin-top: 12px; color: var(--muted); font-size: .73rem; font-weight: 600; }
.entity-key li { display: flex; align-items: center; gap: 6px; }
.entity-key i { width: 9px; height: 9px; border-radius: 50%; background: var(--amber); }
.entity-key .k-locked { border-radius: 2px; background: none; border: 1px solid #a9b5ba; }
.t-arrow { width: 24px; height: 24px; color: var(--mark); justify-self: center; transform: rotate(90deg); }
.boundary { display: flex; align-items: center; justify-content: center; min-height: 34px; border-top: 2px dashed var(--amber); border-bottom: 2px dashed var(--amber); background: var(--amber-soft); color: var(--amber-ink); font-size: .68rem; font-weight: 750; letter-spacing: .1em; text-transform: uppercase; transition: background .3s; }
.t-return { display: flex; align-items: center; gap: 8px; padding: 10px 14px; border: 1px dashed #9dcdd1; border-radius: 12px; color: var(--teal); font-size: .84rem; font-weight: 650; transition: background .3s; }
.t-return svg { width: 22px; height: 22px; }
.reach-out [data-beat].is-lit { border-color: var(--teal); background: var(--mist); box-shadow: 0 0 0 3px #08798526; }
.reach-out .boundary.is-lit { background: #fbe8c9; }
.reach-out [data-beat].is-answer { border-color: var(--amber); background: var(--amber-soft); box-shadow: 0 0 0 3px #b7821226; }

.files { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; margin-bottom: 16px; }
.files li { display: grid; gap: 3px; padding: 14px; border: 1px solid var(--line); border-radius: 14px; background: var(--white); }
.ext { width: max-content; padding: 3px 8px; border-radius: 6px; background: var(--navy); color: var(--white); font-size: .64rem; font-weight: 800; letter-spacing: .08em; }
.files strong { margin-top: 4px; color: var(--navy); font-size: 1.05rem; font-weight: 700; letter-spacing: -.02em; }
.files li > span:nth-of-type(2) { color: var(--muted); font-size: .8rem; }

@keyframes rise { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }

@media (min-width: 640px) {
  main, .brand-header, .section-nav { padding-inline: 30px; }
  .intro { padding-top: 46px; }
  .before-after { grid-template-columns: 1fr 1fr; }
  .picker { grid-template-columns: 230px minmax(0, 1fr); }
  .picker-rail { border-right: 1px solid var(--line); border-bottom: 0; }
  #provider-tabs { grid-template-columns: 1fr; }
  .skill-flow { grid-template-columns: 1fr 34px 1fr 34px 1fr 34px 1fr; }
  .step { grid-template-columns: 44px minmax(0, 1fr); }
  .step-head { grid-column: 1 / -1; }
  .step > :not(.step-head) { grid-column: 2; }
  .step-row { grid-template-columns: 96px minmax(0, 1fr); align-items: baseline; }
  .field { grid-template-columns: 140px minmax(0, 1fr) auto; align-items: center; }
  .ro-track { flex-direction: row; align-items: stretch; }
  .ro-track > .t-node { flex: 1 1 0; }
  .once-arrow { transform: none; }
  .t-arrow { transform: none; align-self: center; }
  .boundary { min-height: 0; border: 0; border-left: 2px dashed var(--amber); border-right: 2px dashed var(--amber); writing-mode: vertical-rl; }
  .boundary span { transform: rotate(180deg); }
  .t-return { grid-column: 1 / -1; }
}

@media (max-width: 420px) {
  main, .brand-header, .section-nav { padding-inline: 16px; }
  .section-nav select { max-width: 100%; }
  .step { padding: 13px; }
  .step-head h3 { font-size: 1.02rem; }
  .seg { font-size: .64rem; }
  .brand-header img { width: 126px; }
  .brand-header span { max-width: 135px; font-size: .64rem; }
  .intro { padding-top: 28px; }
  .section-heading { grid-template-columns: 30px minmax(0, 1fr); gap: 9px; }
  .section-number { width: 28px; height: 28px; }
  .stat-strip { gap: 6px; }
  .stat-strip li { padding: 10px 6px; border-radius: 11px; }
  .picker { border-radius: 14px; }
  .model-rows li { align-items: flex-start; flex-direction: column; gap: 4px; }
  .hosts { justify-content: flex-start; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}