:root {
  --bg: #f4f2ec;
  --ink: #1a1f1c;
  --muted: #5c6560;
  --card: #fffcf7;
  --line: #d5d0c6;
  --accent: #0d5c52;
  --accent-2: #1f3f66;
  --warn: #8a4b16;
  --ok: #1b5f3c;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  --sans: "Segoe UI", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --mono: ui-monospace, "Cascadia Code", Consolas, monospace;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: var(--sans);
  color: var(--ink);
  background: linear-gradient(180deg, #ebe7df, var(--bg));
  min-height: 100vh;
  line-height: 1.5;
}
.topbar {
  width: min(920px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 1.25rem 0 0;
}
.main-nav {
  display: flex;
  flex-wrap: wrap;
  gap: .45rem;
  margin: .75rem 0 .35rem;
}
.nav-tab {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--muted);
  border-radius: 8px;
  padding: .5rem .85rem;
  font: inherit;
  cursor: pointer;
}
.nav-tab.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.shell {
  width: min(920px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 1rem 0 3rem;
}
.screen { animation: fade .25s ease; }
@keyframes fade {
  from { opacity: .4; }
  to { opacity: 1; }
}
.panel { margin: 1rem 0; }
.panel.discuss { border-left: 3px solid var(--accent); }
.panel.closing { border-left: 3px solid var(--accent-2); }
.plain-list { margin: .5rem 0 0 1.1rem; padding: 0; }
.plain-list li { margin: .35rem 0; }
.prompt-line {
  font-family: var(--serif);
  font-size: 1.15rem;
  color: var(--accent-2);
  margin: .6rem 0;
}
.transition {
  font-family: var(--serif);
  font-size: 1.05rem;
  color: var(--accent);
  border-top: 1px solid var(--line);
  padding-top: 1rem;
  margin-top: 1.25rem;
}
.reveal {
  margin-top: .7rem;
  padding: .75rem 1rem;
  background: rgba(13,92,82,.06);
  border-radius: 8px;
}
.aaa {
  display: grid;
  gap: .65rem;
  margin-top: .7rem;
}
.aaa > div {
  display: grid;
  gap: .2rem;
  padding: .65rem .8rem;
  background: rgba(31,63,102,.05);
  border-radius: 8px;
}
.aaa strong {
  font-family: var(--serif);
  color: var(--accent);
}
.ab-compare {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: .75rem;
  margin: .9rem 0;
}
.ab-compare > div {
  background: #111;
  color: #eee;
  border-radius: 8px;
  padding: .65rem;
}
.ab-compare strong { display: block; font-size: .85rem; margin-bottom: .4rem; color: #cfe8e2; }
.ab-compare img { width: 100%; aspect-ratio: 1; object-fit: contain; background: #000; border-radius: 4px; }
.ab-compare .caption { color: #b7c2bc; font-size: .78rem; }
.ab-expected-text p { margin: .45rem 0; font-size: .9rem; line-height: 1.4; }
.hidden { display: none !important; }
.eyebrow {
  text-transform: uppercase;
  letter-spacing: .06em;
  font-size: .75rem;
  color: var(--muted);
}
h1, h2, h3 { font-family: var(--serif); letter-spacing: -.02em; font-weight: 600; }
h1 { font-size: clamp(1.9rem, 4vw, 2.8rem); line-height: 1.1; margin: .35rem 0 .6rem; }
h2 { font-size: 1.55rem; margin-top: 0; }
.lede { font-size: 1.15rem; color: var(--accent-2); margin-top: 0; }
.caption { color: var(--muted); font-size: .92rem; }
.btn {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  border-radius: 8px;
  padding: .65rem 1rem;
  font: inherit;
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
}
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.nav { display: flex; gap: .6rem; flex-wrap: wrap; margin-top: 1rem; }
.route-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: .8rem;
  margin: 1.2rem 0 1rem;
}
.route-card, .panel, .summary, .level-block {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1rem 1.1rem;
}
.route-card {
  text-align: left;
  cursor: pointer;
  font: inherit;
  color: inherit;
}
.route-card strong { display: block; font-family: var(--serif); font-size: 1.1rem; margin-bottom: .35rem; }
.lab-banner {
  border-radius: 8px;
  padding: .7rem 1rem;
  margin: 1rem 0;
  border: 1px solid var(--line);
  background: rgba(31,63,102,.06);
  color: var(--accent-2);
  font-size: .95rem;
}
.lab-banner.live { background: rgba(27,95,60,.08); color: var(--ok); }
.lab-banner.sample { background: rgba(138,75,22,.08); color: var(--warn); }
.lab-terminal, .flow {
  background: #15201c;
  color: #e7f2ee;
  padding: 1rem;
  border-radius: 8px;
  overflow: auto;
  white-space: pre-wrap;
  font-family: var(--mono);
  font-size: .86rem;
  line-height: 1.45;
  min-height: 6rem;
}
.prompt-box, .code-box {
  background: #15201c;
  color: #e7f2ee;
  padding: .85rem 1rem;
  border-radius: 8px;
  overflow: auto;
  white-space: pre-wrap;
  font-family: var(--mono);
  font-size: .84rem;
  line-height: 1.4;
  max-height: 320px;
}
.callout {
  background: rgba(138,75,22,.08);
  border-left: 3px solid var(--warn);
  padding: .75rem 1rem;
}
.steps {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
  padding: 0;
  margin: 0 0 1rem;
}
.steps .step {
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 999px;
  padding: .3rem .65rem;
  font-size: .8rem;
  color: var(--muted);
}
.steps .step.active { border-color: var(--accent); color: var(--accent); background: rgba(13,92,82,.08); }
.steps .step.done { border-color: var(--ok); color: var(--ok); }
.scenario-tabs { display: flex; flex-wrap: wrap; gap: .45rem; margin: .7rem 0; }
.scenario-tab {
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 999px;
  padding: .4rem .75rem;
  font: inherit;
  cursor: pointer;
  color: var(--muted);
}
.scenario-tab.active { background: var(--accent); border-color: var(--accent); color: #fff; }
.level-block { margin-bottom: .8rem; }
.level-block h3 { margin-top: 0; }
.field-label { display: block; margin: .6rem 0 .35rem; font-size: .95rem; }
textarea {
  width: 100%;
  font: inherit;
  padding: .7rem .8rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  resize: vertical;
}
.pack-feedback {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 1rem;
  margin-top: .7rem;
}
.summary ul { margin: .4rem 0 1rem 1.1rem; }
code {
  font-family: var(--mono);
  font-size: .9em;
  background: rgba(0,0,0,.05);
  padding: .1rem .3rem;
  border-radius: 4px;
}
.intro-controls {
  display: grid;
  gap: .6rem;
  margin: .7rem 0 1rem;
}
.intro-controls label { display: grid; gap: .25rem; font-size: .92rem; }
.intro-stage {
  position: relative;
  width: min(420px, 100%);
  margin: 0 auto 1rem;
  background: #111;
  border-radius: 8px;
  overflow: hidden;
  aspect-ratio: 1;
}
.intro-stage img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}
.intro-overlay-layer {
  position: absolute;
  inset: 0;
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center;
  pointer-events: none;
}
.hidden-layer { display: none !important; }
.legend {
  display: flex;
  flex-wrap: wrap;
  gap: .55rem .9rem;
  margin-top: .5rem;
  font-size: .88rem;
}
.legend-item { display: inline-flex; align-items: center; gap: .35rem; }
.legend-item i {
  width: .75rem;
  height: .75rem;
  border-radius: 2px;
  display: inline-block;
}
details {
  margin: .8rem 0;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: .55rem .9rem;
}
details summary { cursor: pointer; font-weight: 600; }