:root{--bg:#0b0e0d;--panel:#121714;--panel2:#171d19;--ink:#eef4ef;--muted:#aeb9b1;--accent:#c7ffca;--line:#2a342d;--warm:#e9d7a8}
*{box-sizing:border-box} html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.55}
main{max-width:1280px;margin:auto;padding:40px 28px 90px}
.hero{padding:70px 0 64px;border-bottom:1px solid var(--line)}
.eyebrow,.change-label{font-size:12px;letter-spacing:.16em;font-weight:800;color:var(--accent)}
h1{font-size:clamp(56px,10vw,126px);line-height:.88;margin:12px 0 28px;letter-spacing:-.06em}
h2{font-size:clamp(28px,4vw,48px);line-height:1.05;letter-spacing:-.035em;margin:6px 0 16px}
h3{font-size:15px;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);margin:0 0 12px}
.dek{max-width:900px;font-size:22px;color:#d4ddd6}
.thesis,.next{margin-top:34px;border-left:3px solid var(--accent);padding:10px 0 10px 22px;display:grid;gap:4px;max-width:900px}
.thesis strong,.next strong{font-size:13px;text-transform:uppercase;letter-spacing:.1em;color:var(--accent)}
.start-block,.step{padding:64px 0;border-bottom:1px solid var(--line)}
.start-block{display:grid;grid-template-columns:150px 1fr;gap:28px;align-items:start}
.start-block figure{grid-column:2}
.step-head{display:grid;grid-template-columns:90px 1fr;gap:18px;align-items:start;margin-bottom:32px}
.step-num{font-size:38px;font-weight:900;color:var(--accent);line-height:1}.start-block>.step-num{font-size:22px;letter-spacing:.12em;padding-top:10px}
.reference-row{display:grid;grid-template-columns:minmax(0,1.05fr) minmax(330px,.95fr);gap:28px;align-items:start}
.prompt-panel{background:var(--panel);border:1px solid var(--line);padding:26px;border-radius:14px;position:sticky;top:16px}
.prompt{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:14px;color:#e6eee8;white-space:normal}
.note{font-size:12px;color:var(--muted);border-top:1px solid var(--line);padding-top:14px;margin-top:18px}
.results-title{margin-top:34px}
.results-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}
.results-grid.single{grid-template-columns:minmax(0,760px)}
.image-card{margin:0;background:var(--panel);border:1px solid var(--line);border-radius:12px;overflow:hidden}
.image-card.chosen{border:2px solid var(--accent);box-shadow:0 0 0 3px rgba(199,255,202,.08)}
.img-wrap{position:relative;background:#050706}
img{display:block;width:100%;height:auto}
figcaption{padding:11px 13px;font-size:13px;color:var(--muted)}
.rejected-badge{background:#e9d7a8!important;color:#0b0e0d!important}.badge{position:absolute;top:10px;right:10px;background:var(--accent);color:#0b0e0d;font-size:11px;font-weight:900;letter-spacing:.1em;padding:6px 8px;border-radius:999px}
.decision{margin:22px 0 0;background:#142018;border:1px solid #2c4932;border-radius:12px;padding:18px 20px}
.decision strong{color:var(--accent)} .decision span{color:#d5dfd7}
.decision.noselect{background:#211b14;border-color:#51412a}.decision.noselect strong{color:var(--warm)}
.change{margin-top:16px;background:var(--panel2);border-radius:12px;padding:18px 20px}
.change p{margin:5px 0 0;color:#d8e0da}
.summary,.architecture{padding:72px 0;border-bottom:1px solid var(--line)}.summary-intro{max-width:920px;font-size:19px;color:#d3ddd5}.evolution{margin-top:18px;background:var(--panel2);border:1px solid var(--line);border-radius:12px;padding:20px 22px}.evolution p{margin:8px 0 0;color:#d8e0da}
.takeaway-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;margin-top:32px}
.takeaway-grid>div{background:var(--panel);border:1px solid var(--line);padding:22px;border-radius:12px}
.takeaway-grid strong{font-size:16px}.takeaway-grid p{color:var(--muted);margin:8px 0 0}
.flow{display:flex;flex-wrap:wrap;align-items:center;gap:10px;margin:32px 0;background:var(--panel);padding:22px;border:1px solid var(--line);border-radius:12px}
.flow span{background:var(--panel2);border:1px solid var(--line);border-radius:999px;padding:9px 13px;font-size:13px}
.flow b{color:var(--accent)}
.architecture>p{max-width:900px;color:#cbd5cd;font-size:18px}
footer{padding-top:34px;display:grid;gap:6px;color:var(--muted);font-size:13px} footer strong{color:var(--ink)}
@media(max-width:800px){
 main{padding:24px 16px 60px}.reference-row,.takeaway-grid{grid-template-columns:1fr}.results-grid{grid-template-columns:1fr}
 .start-block,.step-head{grid-template-columns:58px 1fr}.prompt-panel{position:static}.start-block figure{grid-column:1/-1}
}

.intent-highlights{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:18px 0 4px}
.intent-card{border-radius:12px;padding:16px 18px;border:1px solid var(--line);background:var(--panel)}
.intent-card.aesthetic{border-left:4px solid var(--warm)}
.intent-card.prompt-shift{border-left:4px solid var(--accent)}
.intent-card .mini-label{display:block;font-size:11px;letter-spacing:.12em;font-weight:900;margin-bottom:7px}
.intent-card.aesthetic .mini-label{color:var(--warm)}
.intent-card.prompt-shift .mini-label{color:var(--accent)}
.intent-card p{margin:0;color:#d8e0da;font-size:14px}
@media(max-width:800px){.intent-highlights{grid-template-columns:1fr}}

.start-label{font-size:16px!important;letter-spacing:.08em;padding-top:5px}
.start-block{display:contents!important}
.start-content,.step-content{margin-left:0!important;padding-left:0!important}

.frame-badge{
  position:absolute; top:10px; left:10px; z-index:5;
  min-width:34px; height:34px; padding:0 10px;
  display:flex; align-items:center; justify-content:center;
  border-radius:999px; background:rgba(10,14,12,.88);
  color:#fff; border:1px solid rgba(255,255,255,.35);
  font-weight:800; font-size:18px; letter-spacing:.03em;
  box-shadow:0 2px 10px rgba(0,0,0,.28);
}
.img-wrap{position:relative}
.frame-sequence{
  margin:16px 0 28px; padding:14px 18px; border-radius:12px;
  background:rgba(255,255,255,.04); border:1px solid rgba(255,255,255,.12);
  font-size:14px; line-height:1.5;
}
.frame-sequence strong{letter-spacing:.04em}

.motion-lab{margin-top:58px;padding-top:10px}
.motion-lab .lab-intro{max-width:980px;font-size:18px;line-height:1.65;color:var(--muted);margin-bottom:26px}
.method-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;margin:24px 0 30px}
.method-card{background:rgba(255,255,255,.035);border:1px solid rgba(255,255,255,.12);border-radius:16px;padding:18px}
.method-card strong{display:block;font-size:17px;margin-bottom:8px}
.method-card p{margin:5px 0;color:var(--muted);line-height:1.5}
.motion-test{margin:30px 0 36px;padding:22px;border:1px solid rgba(255,255,255,.12);border-radius:18px;background:rgba(255,255,255,.025)}
.motion-test.pass{border-left:5px solid #8bd3a8}
.motion-test.fail{border-left:5px solid #e6a4a4}
.motion-test.info{border-left:5px solid #e9d7a8}
.motion-head{display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin-bottom:12px}
.motion-head h3{margin:0;font-size:22px}
.result-pill{font-size:11px;font-weight:900;letter-spacing:.1em;padding:6px 9px;border-radius:999px;background:rgba(255,255,255,.09)}
.result-pill.pass{background:#8bd3a8;color:#0b0e0d}
.result-pill.fail{background:#e6a4a4;color:#0b0e0d}
.result-pill.info{background:#e9d7a8;color:#0b0e0d}
.test-meta{font-size:13px;color:var(--muted);margin-bottom:14px}
.motion-test video{display:block;width:100%;max-width:960px;border-radius:12px;background:#000;margin:14px 0 16px}
.movie-player{margin:18px 0 32px}
.movie-player video{display:block;width:100%;max-width:1100px;border-radius:14px;background:#000}
.canonical-strip{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:10px;margin:18px 0 28px}
.canonical-strip figure{margin:0}
.canonical-strip img{width:100%;border-radius:10px;display:block}
.canonical-strip figcaption{font-size:12px;letter-spacing:.08em;margin-top:8px;color:var(--muted)}
@media(max-width:760px){.canonical-strip{grid-template-columns:1fr 1fr}}
.prompt-box{white-space:pre-wrap;background:rgba(0,0,0,.22);border:1px solid rgba(255,255,255,.09);padding:14px 16px;border-radius:12px;font-size:13px;line-height:1.55;color:#d7ddd9;margin:14px 0}
.motion-test p{line-height:1.6}
.finding{margin-top:28px;padding:20px;border-radius:16px;background:rgba(255,255,255,.045);border:1px solid rgba(255,255,255,.13)}
.finding strong{display:block;margin-bottom:8px;font-size:18px}
.waypoint-row{display:grid;grid-template-columns:minmax(220px,360px) 1fr;gap:20px;align-items:start;margin:16px 0}
.waypoint-row img{width:100%;border-radius:12px;display:block}
@media(max-width:760px){.method-grid,.waypoint-row{grid-template-columns:1fr}}








html{scroll-behavior:smooth;scroll-padding-top:90px}
@media(max-width:760px){
  
}

.story{margin:54px 0 58px;padding:30px 0 6px}
.story h2,.ready-code h2,.section-intro h2{max-width:980px}
.story-grid{display:grid;grid-template-columns:1.35fr .85fr;gap:24px;align-items:start;margin:22px 0}
.story-grid p,.story-note,.scope-note{font-size:16px;line-height:1.65;color:var(--muted)}
.story-card{padding:22px;border-radius:17px;border:1px solid rgba(255,255,255,.14);background:rgba(255,255,255,.04)}
.story-card strong{display:block;font-size:19px;margin-bottom:10px}
.problem-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin:28px 0}
.problem-strip>div{padding:16px;border-radius:14px;background:rgba(255,255,255,.035);border:1px solid rgba(255,255,255,.1);font-size:14px;line-height:1.5;color:var(--muted)}
.problem-strip b{color:inherit}
.thesis-large{margin-top:28px}
.loop-diagram,.code-flow{display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap;margin:24px 0;padding:18px;border-radius:14px;background:rgba(0,0,0,.18);border:1px solid rgba(255,255,255,.1)}
.loop-diagram span,.code-flow span{font-size:12px;font-weight:900;letter-spacing:.08em;padding:8px 10px;border-radius:999px;background:rgba(255,255,255,.07)}
.loop-diagram b,.code-flow b{color:var(--muted)}
.section-intro{margin:48px 0 20px;padding-top:12px}
.section-intro p{max-width:980px;font-size:17px;line-height:1.65;color:var(--muted)}
.ready-code{margin:54px 0;padding:30px 0}
.insight-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin:26px 0}
.insight-card{padding:20px;border-radius:16px;background:rgba(255,255,255,.035);border:1px solid rgba(255,255,255,.11)}
.insight-card strong{font-size:17px;display:block;margin-bottom:9px}
.insight-card p{font-size:14px;line-height:1.55;color:var(--muted);margin:0}
.code-milestone{margin:30px 0 20px;padding:22px;border-radius:17px;border:1px solid rgba(255,255,255,.14);background:rgba(255,255,255,.04)}
.code-milestone>strong{display:block;font-size:20px;margin-bottom:8px}
.code-milestone>p{line-height:1.65;color:var(--muted)}
@media(max-width:800px){
  .story-grid,.problem-strip,.insight-grid{grid-template-columns:1fr}
}

/* v13 navigation refinement */




.frame-sequence{
  margin-top:18px !important;
  margin-bottom:34px !important;
}

/* v15 side navigation */




body{
  padding-left:170px;
}
@media(max-width:1100px){
  
  
}

/* Canonical journey film reel */
.canonical-reel{
  margin:52px 0 64px;
  padding-top:8px;
}
.canonical-reel>p{
  max-width:920px;
  color:var(--muted);
  line-height:1.6;
}
.filmstrip{
  display:grid;
  grid-template-columns:repeat(8, minmax(0,1fr));
  gap:8px;
  margin-top:20px;
  padding:12px;
  border-radius:14px;
  background:rgba(0,0,0,.22);
  border:1px solid rgba(255,255,255,.11);
  overflow:hidden;
}
.film-cell{
  margin:0;
  min-width:0;
  position:relative;
}
.film-cell img{
  width:100%;
  aspect-ratio:16/9;
  object-fit:cover;
  display:block;
  border-radius:5px;
}
.film-cell figcaption{
  position:absolute;
  left:5px;
  bottom:5px;
  width:22px;
  height:22px;
  border-radius:50%;
  display:grid;
  place-items:center;
  font-size:11px;
  font-weight:900;
  background:rgba(0,0,0,.72);
  border:1px solid rgba(255,255,255,.35);
}
@media(max-width:900px){
  .filmstrip{
    overflow-x:auto;
    display:flex;
  }
  .film-cell{
    flex:0 0 150px;
  }
}
.story a[href*="5050.dev"]{
  color:inherit;
  text-decoration:underline;
  text-decoration-thickness:1px;
  text-underline-offset:3px;
}

/* (old v16 #toc overrides removed — new .sidebar rules below) */
.film-cell{
  position:relative !important;
  overflow:hidden !important;
  border-radius:6px !important;
  background:#090b0a;
}
.film-cell img{
  width:100% !important;
  height:auto !important;
  aspect-ratio:16/9 !important;
  object-fit:cover !important;
  display:block !important;
  border-radius:6px !important;
}
.film-cell figcaption{
  position:absolute !important;
  top:6px !important;
  left:6px !important;
  bottom:auto !important;
  width:24px !important;
  height:24px !important;
  margin:0 !important;
  border-radius:999px !important;
  display:grid !important;
  place-items:center !important;
  font-size:11px !important;
  line-height:1 !important;
  font-weight:900 !important;
  color:#fff !important;
  background:rgba(0,0,0,.78) !important;
  border:1px solid rgba(255,255,255,.5) !important;
  box-sizing:border-box !important;
  pointer-events:none !important;
}

/* (old v17/v18 #toc overrides removed — new .sidebar rules below) */
.film-cell:hover,
.film-cell:focus-visible{
  transform:translateY(-2px);
  box-shadow:0 8px 20px rgba(0,0,0,.28);
  outline:none;
}
.film-cell::after{
  content:"";
  position:absolute;
  inset:0;
  border-radius:6px;
  border:1px solid transparent;
  pointer-events:none;
}
.film-cell:hover::after,
.film-cell:focus-visible::after{
  border-color:rgba(255,255,255,.35);
}

/* Lightbox */
.journey-lightbox{
  position:fixed;
  inset:0;
  z-index:10000;
  display:none;
}
.journey-lightbox.open{
  display:block;
}
.lb-backdrop{
  position:absolute;
  inset:0;
  background:rgba(0,0,0,.86);
  backdrop-filter:blur(8px);
}
.lb-dialog{
  position:absolute;
  inset:3vh 3vw;
  display:grid;
  grid-template-columns:64px minmax(0,1fr) 64px;
  grid-template-rows:minmax(0,1fr) auto;
  align-items:center;
  gap:14px;
}
.lb-stage{
  grid-column:2;
  grid-row:1;
  min-width:0;
  min-height:0;
  display:flex;
  flex-direction:column;
  align-items:center;
  justify-content:center;
}
.lb-image{
  display:block;
  max-width:100%;
  max-height:82vh;
  width:auto;
  height:auto;
  object-fit:contain;
  border-radius:10px;
  box-shadow:0 18px 60px rgba(0,0,0,.45);
}
.lb-video{
  display:block;
  max-width:100%;
  max-height:82vh;
  width:auto;
  height:auto;
  border-radius:10px;
  background:#050706;
  box-shadow:0 18px 60px rgba(0,0,0,.45);
}
.lb-video[hidden]{
  display:none;
}
.lb-meta{
  width:min(100%,1200px);
  display:flex;
  justify-content:space-between;
  gap:16px;
  margin-top:12px;
  color:#fff;
}
.lb-label{
  font-size:18px;
  font-weight:900;
  letter-spacing:.06em;
}
.lb-counter{
  font-size:13px;
  color:rgba(255,255,255,.7);
}
.lb-prev,.lb-next,.lb-close{
  border:0;
  background:rgba(255,255,255,.08);
  color:#fff;
  cursor:pointer;
}
.lb-prev,.lb-next{
  width:52px;
  height:52px;
  border-radius:999px;
  font-size:42px;
  line-height:1;
}
.lb-prev{grid-column:1;grid-row:1}
.lb-next{grid-column:3;grid-row:1}
.lb-close{
  position:absolute;
  right:0;
  top:0;
  width:44px;
  height:44px;
  border-radius:999px;
  font-size:28px;
  z-index:2;
}
.lb-prev:hover,.lb-next:hover,.lb-close:hover{
  background:rgba(255,255,255,.16);
}
.lb-hint{
  grid-column:1 / -1;
  grid-row:2;
  text-align:center;
  color:rgba(255,255,255,.55);
  font-size:12px;
}
body.lb-open{
  overflow:hidden;
}
@media(max-width:700px){
  .lb-dialog{
    inset:2vh 10px;
    grid-template-columns:44px minmax(0,1fr) 44px;
    gap:8px;
  }
  .lb-prev,.lb-next{
    width:40px;
    height:40px;
    font-size:32px;
  }
  .lb-image{
    max-height:76vh;
  }
  .lb-video{
    max-height:76vh;
    width:100%;
  }
}

/* v19: sequence audit + controlled B→D breakthrough */
.sequence-audit{
  padding:58px 0 66px;
  border-bottom:1px solid var(--line);
}
.sequence-audit .audit-intro{
  max-width:920px;
  color:#d3ddd5;
  font-size:19px;
}
.audit-grid{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:14px;
  margin:26px 0 20px;
}
.audit-grid>div{
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:12px;
  padding:18px;
}
.audit-grid strong{
  color:var(--warm);
  font-size:17px;
}
.audit-grid p{
  color:var(--muted);
  margin:7px 0 0;
}
.reel-finding{
  border-left:5px solid var(--accent);
}
.motion-test.breakthrough{
  background:rgba(139,211,168,.055);
  box-shadow:0 0 0 1px rgba(139,211,168,.10) inset;
}
@media(max-width:800px){
  .audit-grid{grid-template-columns:1fr}
}


.section-anchor{display:block;position:relative;scroll-margin-top:24px;}
.tunneltv-origin-logo{margin:28px 0 24px;display:flex;justify-content:flex-start}
.tunneltv-origin-logo img{display:block;width:min(340px,72vw);height:auto;object-fit:contain}


.tunneltv-origin-float{float:left;width:min(240px,32%);margin:0 28px 14px 0;}
.tunneltv-origin-float img{display:block;width:100%;height:auto;}
.tunneltv-origin-copy::after{content:"";display:block;clear:both;}
@media (max-width:700px){.tunneltv-origin-float{float:none;width:min(260px,70%);margin:0 auto 18px;}}


/* ── Sidebar navigation ──────────────────────────────────────────── */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: 220px;
  height: 100vh;
  background: var(--panel);
  border-right: 1px solid var(--line);
  padding: 20px 14px 28px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  overflow-y: auto;
  z-index: 100;
}
.sidebar-title {
  font-size: 11px;
  font-weight: 900;
  letter-spacing: .16em;
  color: var(--accent);
  margin-bottom: 12px;
}
.sidebar a {
  display: block;
  padding: 8px 10px;
  color: var(--muted);
  text-decoration: none;
  font-size: 13px;
  border-radius: 6px;
  transition: background .15s, color .15s;
}
.sidebar a:hover {
  background: var(--panel2);
  color: var(--ink);
}
.sidebar a.active {
  background: rgba(199,255,202,.08);
  color: var(--accent);
  font-weight: 700;
}
.sidebar a.nav-home {
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 6px;
}
.nav-group {
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin-top: 12px;
}
.nav-group-label {
  padding: 8px 10px 4px;
  font-size: 10px;
  font-weight: 900;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--accent);
}
.nav-group a {
  padding: 6px 10px 6px 16px;
  font-size: 12px;
}
.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--line);
  color: var(--ink);
  font-size: 22px;
  padding: 6px 10px;
  border-radius: 8px;
  cursor: pointer;
  margin-bottom: 10px;
}

body {
  padding-left: 240px;
}

/* ── Chapter prev/next ──────────────────────────────────────────── */
.chapter-nav {
  display: flex;
  justify-content: space-between;
  padding: 40px 0 20px;
  border-top: 1px solid var(--line);
  margin-top: 60px;
}
.chapter-nav a {
  color: var(--accent);
  text-decoration: none;
  font-size: 14px;
  font-weight: 600;
}
.chapter-nav a:hover {
  text-decoration: underline;
}
.chapter-nav .next-link {
  margin-left: auto;
}

/* ── Mobile responsive ──────────────────────────────────────────── */
@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    top: 0;
    left: -260px;
    width: 240px;
    height: 100vh;
    transition: left .25s ease;
    z-index: 200;
    box-shadow: none;
  }
  .sidebar.open {
    left: 0;
    box-shadow: 4px 0 20px rgba(0,0,0,.5);
  }
  .nav-toggle {
    display: block;
    position: fixed;
    top: 12px;
    left: 12px;
    z-index: 300;
    background: var(--panel);
  }
  body {
    padding-left: 0;
  }
}

/* Live hackathon log. Newest article first. */
.live-update {
  padding: 40px 0;
  border-bottom: 1px solid var(--line);
}
.live-update time {
  display: block;
  font-size: 12px;
  letter-spacing: .16em;
  font-weight: 800;
  color: var(--accent);
}
.live-update h2 {
  margin-top: 8px;
}
.live-update p {
  max-width: 42rem;
  margin: 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.6;
}
.live-images {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 320px), 1fr));
  gap: 14px;
  margin-top: 22px;
}
.live-images img {
  width: 100%;
  height: auto;
  cursor: zoom-in;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: #050706;
}
.live-images video[data-gallery-video] {
  display:block;
  width:100%;
  max-height:420px;
  aspect-ratio:16 / 9;
  object-fit:cover;
  cursor:zoom-in;
  border-radius:12px;
  border:1px solid var(--line);
  background:#050706;
}
.live-inline-video {
  display:block;
  width:min(100%, 960px);
  max-height:72vh;
  margin-top:22px;
  border-radius:12px;
  border:1px solid var(--line);
  background:#050706;
}