/* GUTS landing — token-for-token the Loop Designer palette
   (designer/app/globals.css), so the static site and the
   /designer/ app read as one product. */

:root {
  --font:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
    Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", "Cascadia Code", Menlo, Consolas, monospace;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);

  color-scheme: dark light;
}

/* Dark is the default (matches the designer's default); light themes opt in
   via prefers-color-scheme. Pure CSS — no theme JS on the landing page. */
:root {
  --bg: #0e1116;
  --bg-soft: #141922;
  --surface: #1a212c;
  --surface-hover: #202a38;
  --border: #2a3444;
  --border-soft: #222b39;
  --text: #e7ebf1;
  --text-muted: #8b95a7;
  --text-faint: #5f6a7e;

  --accent: #6f9bff;
  --accent-strong: #5b8cff;
  --accent-soft: #1d2c47;
  --accent-ink: #0c1322;

  --ok: #4fd39e;
  --warn: #e8c06a;
  --error: #ff7b72;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f4f6fa;
    --bg-soft: #eceff5;
    --surface: #ffffff;
    --surface-hover: #f1f4f9;
    --border: #dce2ec;
    --border-soft: #e6eaf1;
    --text: #1c2230;
    --text-muted: #5c6780;
    --text-faint: #98a2b5;

    --accent: #3d6bff;
    --accent-strong: #2f5ae0;
    --accent-soft: #e4ebff;
    --accent-ink: #ffffff;

    --ok: #15803d;
    --warn: #a16207;
    --error: #dc2626;
    --shadow: 0 10px 30px rgba(15, 23, 42, 0.12);
  }
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

main {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 20px 60px;
}

/* ── Header ─────────────────────────────────────────────────────────── */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 20px;
  border-bottom: 1px solid var(--border-soft);
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px);
}

.brand { display: flex; align-items: center; gap: 10px; }
.brand img { display: block; }
.brand-name {
  font-weight: 700;
  font-size: 18px;
  letter-spacing: 0.08em;
}

.site-header nav { display: flex; align-items: center; gap: 18px; }
.site-header nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 14px;
}
.site-header nav a:hover { color: var(--text); }

/* ── Pills / buttons ────────────────────────────────────────────────── */

.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--accent);
  color: var(--accent-ink);
  border-radius: 999px;
  padding: 8px 16px;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 120ms var(--ease), background 120ms var(--ease);
}
.pill:hover { background: var(--accent-strong); transform: translateY(-1px); }
.pill.big { padding: 12px 22px; font-size: 16px; }

.ghost {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 14px;
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 8px 16px;
  background: transparent;
}
.ghost:hover { color: var(--text); border-color: var(--text-faint); }

button {
  font-family: inherit;
}
#replay-btn {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 7px 14px;
  font-size: 13px;
  cursor: pointer;
}
#replay-btn:hover { background: var(--surface-hover); }
#replay-btn:disabled { opacity: 0.5; cursor: default; }

/* ── Hero ───────────────────────────────────────────────────────────── */

.hero { padding: 64px 0 28px; }
.hero h1 {
  margin: 0 0 14px;
  font-size: clamp(30px, 5vw, 46px);
  line-height: 1.12;
  letter-spacing: -0.02em;
}
.hero .hl {
  color: var(--accent);
}
.hero .sub {
  margin: 0;
  max-width: 720px;
  color: var(--text-muted);
  font-size: 17px;
}
.hero .sub em { color: var(--text); font-style: normal; font-weight: 600; }

/* ── Replay card ────────────────────────────────────────────────────── */

.replay-card {
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: linear-gradient(180deg, var(--bg-soft), var(--bg) 60%);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.replay-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  padding: 18px 20px 14px;
  border-bottom: 1px solid var(--border-soft);
}
.eyebrow {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 6px;
}
.replay-head .meta {
  margin: 0;
  color: var(--text-muted);
  font-size: 13px;
  font-family: var(--mono);
}
.replay-head .meta b { color: var(--text); font-weight: 600; }

.replay-body {
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: 0;
}

.canvas-wrap {
  padding: 18px;
  border-right: 1px solid var(--border-soft);
  min-width: 0;
}
#replay-svg { width: 100%; height: auto; display: block; }
.stage-note {
  margin-top: 10px;
  font-size: 12.5px;
  color: var(--text-faint);
  font-family: var(--mono);
  min-height: 18px;
}

.feed-wrap { padding: 18px; min-width: 0; display: flex; flex-direction: column; }
.feed-title {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 10px;
}

.feed {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-height: 190px;
  max-height: 330px;
  overflow-y: auto;
}
.feed li {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 7px 10px;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  background: var(--surface);
  animation: feed-in 240ms var(--ease);
}
@keyframes feed-in {
  from { opacity: 0; transform: translateY(4px); }
  to   { opacity: 1; transform: none; }
}
.feed .ev-line { display: flex; align-items: center; gap: 8px; }
.feed .ev-kind {
  font-family: var(--mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.04em;
  padding: 1px 7px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
}
.feed .ev-kind.kind-ok  { background: color-mix(in srgb, var(--ok) 16%, transparent); color: var(--ok); }
.feed .ev-kind.kind-skip { background: color-mix(in srgb, var(--text-faint) 20%, transparent); color: var(--text-muted); }
.feed .ev-kind.kind-err { background: color-mix(in srgb, var(--error) 16%, transparent); color: var(--error); }
.feed .ev-node { font-family: var(--mono); font-size: 12.5px; color: var(--text); }
.feed .ev-detail {
  font-size: 12px;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.answer {
  margin-top: 12px;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  background: var(--surface);
  padding: 10px 12px;
}
.answer-label {
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 6px;
}
.answer p {
  margin: 0;
  font-size: 13.5px;
  color: var(--text);
  white-space: pre-wrap;
}

/* ── SVG canvas states ──────────────────────────────────────────────── */

.rp-node .box {
  fill: var(--surface);
  stroke: var(--border);
  stroke-width: 1.25;
  transition: fill 200ms var(--ease), stroke 200ms var(--ease);
}
.rp-node .title { font: 700 14px var(--mono); fill: var(--text); }
.rp-node .kind { font: 500 11px var(--font); fill: var(--text-muted); }
.rp-node .sub  { font: 500 10.5px var(--mono); fill: var(--text-faint); }

.rp-node.running .box {
  fill: var(--accent-soft);
  stroke: var(--accent);
  stroke-width: 2;
}
.rp-node.ok .box {
  fill: color-mix(in srgb, var(--ok) 10%, var(--surface));
  stroke: var(--ok);
}
.rp-node.skipped .box { fill: var(--surface); stroke: var(--border-soft); stroke-dasharray: 4 3; }
.rp-node.skipped .title, .rp-node.skipped .kind, .rp-node.skipped .sub { opacity: 0.55; }
.rp-node.failed .box { stroke: var(--error); }

.rp-edge .line {
  fill: none;
  stroke: var(--text-faint);
  stroke-width: 1.5;
  opacity: 0.65;
  transition: stroke 200ms var(--ease), opacity 200ms var(--ease);
}
.rp-edge.control .line { stroke-dasharray: 6 4; }
.rp-edge.lit .line { stroke: var(--accent); opacity: 1; stroke-width: 2; }

.rp-status { font: 600 11px var(--mono); }
.rp-badge { fill: var(--text-faint); }

/* ── How it works ───────────────────────────────────────────────────── */

.how { margin-top: 56px; }
.how h3 {
  margin: 0 0 16px;
  font-size: 20px;
  letter-spacing: -0.01em;
}
.cards {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}
.card {
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-md);
  background: var(--bg-soft);
  padding: 16px;
}
.card h4 { margin: 0 0 8px; font-size: 15px; }
.card p { margin: 0; font-size: 13.5px; color: var(--text-muted); }
.card em { font-style: normal; color: var(--text); font-weight: 600; }

/* ── CTA / footer ───────────────────────────────────────────────────── */

.cta-row {
  margin-top: 44px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

footer {
  max-width: 980px;
  margin: 48px auto 0;
  padding: 18px 20px 40px;
  border-top: 1px solid var(--border-soft);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px;
  color: var(--text-faint);
  font-size: 12.5px;
}
footer code { font-family: var(--mono); font-size: 11.5px; }
.endpoint { font-family: var(--mono); }

/* ── Small screens ──────────────────────────────────────────────────── */

.visually-hidden {
  position: absolute; width: 1px; height: 1px;
  clip: rect(0 0 0 0); overflow: hidden; white-space: nowrap;
}

@media (max-width: 760px) {
  .replay-body { grid-template-columns: 1fr; }
  .canvas-wrap { border-right: none; border-bottom: 1px solid var(--border-soft); }
  .cards { grid-template-columns: 1fr; }
  .feed { max-height: 240px; }
  .hero { padding-top: 40px; }
}