/* ===========================================================
   NEURO — design tokens
   A quiet system built around one idea: rows and columns
   (the language of spreadsheets) resolving into calm structure.
=========================================================== */
:root{
  --bg:            #FAFAFA;
  --surface:       #FFFFFF;
  --surface-alt:   #FBFBFC;
  --ink:           #14161F;
  --ink-soft:      #3A3C46;
  --ink-muted:     #6E7180;
  --ink-faint:     #A6A8B3;
  --line:          #E4E6EC;
  --line-soft:     #EEEFF3;
  --accent:        #4640DE;
  --accent-ink:    #3733B0;
  --accent-soft:   #EDECFC;
  --accent-mid:    #8A87ED;
  --amber:         #D97706;
  --amber-soft:    #FFF3E4;
  --green:         #2E9A5C;
  --green-soft:    #E7F7EE;

  --font-display:  'Space Grotesk', 'Inter', sans-serif;
  --font-body:     'Inter', sans-serif;
  --font-mono:     'IBM Plex Mono', monospace;

  --ease:          cubic-bezier(.22,.68,.16,1);
  --topbar-h:       76px;
  --navbar-h:       84px;
}

*{ box-sizing:border-box; }
html,body{
  margin:0; padding:0; height:100%;
  background:var(--bg); color:var(--ink);
  font-family:var(--font-body);
  overflow:hidden;
  -webkit-font-smoothing:antialiased;
}
body{ position:relative; }
::selection{ background:var(--accent-soft); color:var(--accent-ink); }
button{ font-family:inherit; cursor:pointer; }
a{ color:inherit; }

@media (prefers-reduced-motion: reduce){
  *{ animation-duration:.001ms !important; transition-duration:.001ms !important; }
}

/* ---------------------------------------------------------
   Ambient ledger-grid backdrop — the spreadsheet motif,
   kept faint enough to read as texture, not decoration.
--------------------------------------------------------- */
.ledger-backdrop{
  position:fixed; inset:0; z-index:0;
  color:var(--line);
  opacity:.55;
  pointer-events:none;
  mask-image:radial-gradient(ellipse 80% 60% at 50% 40%, #000 40%, transparent 85%);
}

/* ---------------------------------------------------------
   Top bar
--------------------------------------------------------- */
.topbar{
  position:fixed; top:0; left:0; right:0; height:var(--topbar-h);
  display:flex; align-items:center; justify-content:space-between;
  padding:0 clamp(20px, 4vw, 56px);
  z-index:50;
  pointer-events:none;
}
.brand{
  display:flex; align-items:center; gap:10px;
  font-family:var(--font-display);
  font-weight:600; font-size:16px; letter-spacing:.01em;
  pointer-events:auto;
}
.brand-mark{
  width:9px; height:9px; border-radius:2px;
  background:var(--accent);
  display:inline-block;
}
.brand-name{ color:var(--ink); }
.brand-sep{ color:var(--ink-faint); font-weight:400; }
.brand-co{ color:var(--ink-muted); font-weight:500; font-size:14px; }

.counter{
  font-family:var(--font-mono);
  font-size:13px; letter-spacing:.03em;
  color:var(--ink-muted);
  display:flex; align-items:center; gap:4px;
  pointer-events:auto;
}
.counter-current{ color:var(--ink); font-weight:500; }

/* ---------------------------------------------------------
   Horizontal viewport / track
--------------------------------------------------------- */
.viewport{
  position:relative; z-index:1;
  width:100vw; height:100vh;
  overflow:hidden;
}
.track{
  height:100%;
  display:flex;
  flex-wrap:nowrap;
  will-change:transform;
  transition:transform 900ms var(--ease);
}
.slide{
  flex:0 0 100vw;
  width:100vw; height:100vh;
  display:flex;
  align-items:center;
  justify-content:center;
  padding:calc(var(--topbar-h) + 24px) clamp(24px, 6vw, 96px) calc(var(--navbar-h) + 28px);
  position:relative;
}

/* ---------------------------------------------------------
   INTRO slide
--------------------------------------------------------- */
.slide-intro{
  flex-direction:column;
  text-align:center;
  gap:0;
}
.intro-eyebrow{
  font-family:var(--font-mono);
  font-size:12px; letter-spacing:.14em; text-transform:uppercase;
  color:var(--ink-muted);
  margin-bottom:28px;
  opacity:0; transform:translateY(8px);
}
.intro-eyebrow .dot{ color:var(--accent); }

.intro-word{
  font-family:var(--font-display);
  font-weight:700;
  font-size:clamp(64px, 13vw, 168px);
  line-height:.92;
  letter-spacing:-.02em;
  color:var(--ink);
  opacity:0; transform:translateY(18px);
}
.intro-tagline{
  font-family:var(--font-display);
  font-weight:500;
  font-size:clamp(22px, 3.4vw, 38px);
  line-height:1.25;
  color:var(--ink-soft);
  margin-top:22px;
  opacity:0; transform:translateY(14px);
}
.intro-tagline strong{
  color:var(--accent-ink);
  font-weight:600;
  position:relative;
}
.intro-by{
  margin-top:20px;
  font-family:var(--font-mono);
  font-size:13px; color:var(--ink-faint);
  opacity:0; transform:translateY(10px);
}
.intro-desc{
  margin-top:34px;
  max-width:560px;
  font-size:16px; line-height:1.6;
  color:var(--ink-muted);
  opacity:0; transform:translateY(10px);
}
.intro-cta{
  margin-top:40px;
  display:flex; align-items:center; gap:10px;
  font-family:var(--font-mono);
  font-size:12px; letter-spacing:.06em; text-transform:uppercase;
  color:var(--ink-faint);
  opacity:0;
}
.intro-cta svg{ animation:driftX 1.6s ease-in-out infinite; }
@keyframes driftX{ 0%,100%{ transform:translateX(0);} 50%{ transform:translateX(5px);} }

.slide-intro.is-active .intro-eyebrow{ animation:riseIn 700ms var(--ease) 200ms forwards; }
.slide-intro.is-active .intro-word{ animation:riseIn 800ms var(--ease) 340ms forwards; }
.slide-intro.is-active .intro-tagline{ animation:riseIn 700ms var(--ease) 560ms forwards; }
.slide-intro.is-active .intro-by{ animation:riseIn 700ms var(--ease) 700ms forwards; }
.slide-intro.is-active .intro-desc{ animation:riseIn 700ms var(--ease) 820ms forwards; }
.slide-intro.is-active .intro-cta{ animation:riseIn 700ms var(--ease) 940ms forwards; }

@keyframes riseIn{ to{ opacity:1; transform:translateY(0); } }

/* ---------------------------------------------------------
   Feature slide layout
--------------------------------------------------------- */
.feat-grid{
  display:grid;
  grid-template-columns: minmax(280px, 380px) minmax(0,1fr);
  grid-template-rows: auto 1fr;
  column-gap:clamp(32px, 4vw, 72px);
  row-gap: 28px;
  width:100%;
  max-width:1360px;
  align-items:start;
}

.feat-heading{ grid-column:1; grid-row:1; padding-top:6px; }
.feat-card{ grid-column:1; grid-row:2; }
.feat-visual{ grid-column:2; grid-row:1 / span 2; align-self:center; }

.feat-eyebrow{
  display:flex; align-items:center; gap:10px;
  font-family:var(--font-mono);
  font-size:12px; letter-spacing:.1em;
  color:var(--accent-ink);
  margin-bottom:18px;
  opacity:0; transform:translateY(10px);
}
.feat-eyebrow .num{ color:var(--ink-faint); }
.feat-eyebrow .rule{ width:22px; height:1px; background:var(--line); }
.feat-eyebrow .cat{ text-transform:uppercase; font-weight:500; }

.feat-title{
  font-family:var(--font-display);
  font-weight:600;
  font-size:clamp(30px, 3vw, 44px);
  line-height:1.12;
  letter-spacing:-.015em;
  color:var(--ink);
  opacity:0; transform:translateY(12px);
}
.feat-desc{
  margin-top:16px;
  font-size:15.5px; line-height:1.65;
  color:var(--ink-muted);
  max-width:38ch;
  opacity:0; transform:translateY(10px);
}

.feat-card{
  opacity:0; transform:translateY(14px);
}
.feat-card-inner{
  background:var(--surface);
  border:1px solid var(--line);
  border-radius:16px;
  padding:22px 22px 10px;
}
.feat-card-label{
  font-family:var(--font-mono);
  font-size:11px; letter-spacing:.08em; text-transform:uppercase;
  color:var(--ink-faint);
  margin-bottom:6px;
  display:block;
}
.feat-list{ list-style:none; margin:0; padding:0; }
.feat-list li{
  display:flex; align-items:center; gap:12px;
  padding:12px 0;
  border-top:1px solid var(--line-soft);
  font-size:14.5px; color:var(--ink-soft); font-weight:500;
}
.feat-list li:first-child{ border-top:none; }
.feat-icon{
  flex:0 0 26px; width:26px; height:26px;
  border-radius:7px;
  background:var(--accent-soft);
  display:flex; align-items:center; justify-content:center;
  color:var(--accent);
}
.feat-icon svg{ width:14px; height:14px; }

.feat-visual{ opacity:0; transform:translateY(18px) scale(.98); width:100%; }
.shot-frame{
  position:relative;
  border-radius:16px;
  overflow:hidden;
  border:1px solid var(--line);
  background:var(--surface);
  box-shadow: 0 1px 2px rgba(20,22,31,.04), 0 20px 48px -20px rgba(20,22,31,.18);
  max-width:820px;
  margin:0 auto;
}
.shot-frame img{
  display:block; width:100%; height:auto;
}

.slide-feature.is-active .feat-eyebrow{ animation:riseIn 600ms var(--ease) 120ms forwards; }
.slide-feature.is-active .feat-title{ animation:riseIn 650ms var(--ease) 220ms forwards; }
.slide-feature.is-active .feat-desc{ animation:riseIn 600ms var(--ease) 320ms forwards; }
.slide-feature.is-active .feat-card{ animation:riseIn 650ms var(--ease) 420ms forwards; }
.slide-feature.is-active .feat-visual{ animation:riseInScale 750ms var(--ease) 260ms forwards; }

@keyframes riseInScale{ to{ opacity:1; transform:translateY(0) scale(1); } }

/* ---------------------------------------------------------
   Closing slide
--------------------------------------------------------- */
.slide-close{
  flex-direction:column;
  text-align:center;
}
.close-eyebrow{
  font-family:var(--font-mono); font-size:12px; letter-spacing:.12em; text-transform:uppercase;
  color:var(--ink-muted); margin-bottom:24px;
  opacity:0; transform:translateY(10px);
}
.close-title{
  font-family:var(--font-display); font-weight:600;
  font-size:clamp(34px, 5.2vw, 68px);
  line-height:1.1; letter-spacing:-.02em;
  max-width:920px;
  opacity:0; transform:translateY(14px);
}
.close-title em{ font-style:normal; color:var(--accent-ink); }
.close-desc{
  margin-top:20px; max-width:520px;
  color:var(--ink-muted); font-size:16px; line-height:1.6;
  opacity:0; transform:translateY(10px);
}
.close-actions{
  margin-top:36px;
  display:flex; gap:14px; flex-wrap:wrap; justify-content:center;
  opacity:0; transform:translateY(10px);
}
.btn{
  font-family:var(--font-body);
  font-size:14.5px; font-weight:600;
  padding:13px 26px;
  border-radius:9px;
  border:1px solid transparent;
  transition:transform 200ms var(--ease), background 200ms var(--ease), border-color 200ms var(--ease);
}
.btn-primary{ background:var(--accent); color:#fff; }
.btn-primary:hover{ background:var(--accent-ink); transform:translateY(-1px); }
.btn-ghost{ background:transparent; color:var(--ink); border-color:var(--line); }
.btn-ghost:hover{ border-color:var(--ink-faint); transform:translateY(-1px); }
.btn:focus-visible{ outline:2px solid var(--accent); outline-offset:2px; }

.close-foot{
  margin-top:56px;
  font-family:var(--font-mono); font-size:12px; color:var(--ink-faint);
  opacity:0; transform:translateY(8px);
}

.slide-close.is-active .close-eyebrow{ animation:riseIn 600ms var(--ease) 140ms forwards; }
.slide-close.is-active .close-title{ animation:riseIn 700ms var(--ease) 260ms forwards; }
.slide-close.is-active .close-desc{ animation:riseIn 600ms var(--ease) 420ms forwards; }
.slide-close.is-active .close-actions{ animation:riseIn 600ms var(--ease) 540ms forwards; }
.slide-close.is-active .close-foot{ animation:riseIn 600ms var(--ease) 660ms forwards; }

/* ---------------------------------------------------------
   Bottom nav / dots / progress
--------------------------------------------------------- */
.navbar{
  position:fixed; left:0; right:0; bottom:0; height:var(--navbar-h);
  display:flex; align-items:center; justify-content:center; gap:22px;
  z-index:50;
}
.nav-btn{
  width:42px; height:42px; border-radius:50%;
  border:1px solid var(--line);
  background:var(--surface);
  display:flex; align-items:center; justify-content:center;
  color:var(--ink-soft);
  transition:border-color 180ms var(--ease), transform 180ms var(--ease), color 180ms var(--ease);
}
.nav-btn:hover{ border-color:var(--accent); color:var(--accent-ink); transform:translateY(-1px); }
.nav-btn:active{ transform:translateY(0); }
.nav-btn:disabled{ opacity:.3; pointer-events:none; }
.nav-btn:focus-visible{ outline:2px solid var(--accent); outline-offset:2px; }

.dots{ display:flex; align-items:center; gap:9px; }
.dot{
  width:7px; height:7px; border-radius:50%;
  background:var(--line);
  border:none; padding:0;
  transition:background 200ms var(--ease), width 240ms var(--ease), border-radius 240ms var(--ease);
}
.dot:hover{ background:var(--ink-faint); }
.dot.is-active{ width:22px; border-radius:4px; background:var(--accent); }
.dot:focus-visible{ outline:2px solid var(--accent); outline-offset:3px; }

.progress-track{
  position:fixed; left:0; right:0; bottom:0; height:2px;
  background:var(--line-soft); z-index:49;
}
.progress-fill{
  height:100%; width:0%;
  background:var(--accent);
  transition:width 700ms var(--ease);
}

.scroll-hint{
  position:fixed; right:clamp(20px,4vw,56px); bottom:calc(var(--navbar-h) + 14px);
  z-index:50;
  display:flex; align-items:center; gap:6px;
  font-family:var(--font-mono); font-size:11px; letter-spacing:.06em; text-transform:uppercase;
  color:var(--ink-faint);
  opacity:1;
  transition:opacity 500ms var(--ease);
}
.scroll-hint.is-hidden{ opacity:0; pointer-events:none; }

/* ---------------------------------------------------------
   Responsive
--------------------------------------------------------- */
@media (max-width: 980px){
  .feat-grid{
    grid-template-columns:1fr;
    grid-template-rows:auto auto auto;
    max-width:640px;
  }
  .feat-heading{ grid-column:1; grid-row:1; }
  .feat-visual{ grid-column:1; grid-row:2; }
  .feat-card{ grid-column:1; grid-row:3; }
  .feat-desc{ max-width:none; }
}

@media (max-width: 720px){
  :root{ --topbar-h:64px; --navbar-h:74px; }
  .slide{ padding-top:calc(var(--topbar-h) + 14px); padding-bottom:calc(var(--navbar-h) + 18px); overflow-y:auto; }
  .brand-co, .brand-sep{ display:none; }
  .intro-desc{ font-size:15px; }
  .feat-card-inner{ padding:18px 18px 6px; }
  .scroll-hint{ display:none; }
}

@media (max-width: 480px){
  .intro-word{ font-size:clamp(48px, 16vw, 72px); }
  .intro-tagline{ font-size:20px; }
}