/* ============================================================
   Carbon-inspired design tokens (IBM Carbon: g100 / white)
   ============================================================ */
:root {
  --blue:   #0f62fe;
  --blue-2: #4589ff;
  --green:  #42be65;
  --purple: #be95ff;
  --yellow: #f1c21b;
  --red:    #fa4d56;

  --sans: 'IBM Plex Sans', system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  --mono: 'IBM Plex Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  /* spacing — Carbon scale */
  --s1: .25rem; --s2: .5rem;  --s3: .75rem; --s4: 1rem;
  --s5: 1.5rem; --s6: 2rem;   --s7: 3rem;   --s8: 4rem; --s9: 6rem;

  --maxw: 1280px;
  --ease: cubic-bezier(.2, .8, .2, 1);
}

/* Dark theme (Carbon g100) */
html[data-theme="dark"] {
  --bg:        #161616;
  --bg-2:      #0b0b0b;
  --layer:     #262626;
  --layer-2:   #393939;
  --layer-hover:#333333;
  --text:      #f4f4f4;
  --text-2:    #c6c6c6;
  --text-3:    #8d8d8d;
  --border:    #393939;
  --border-2:  #525252;
  --grid-line: rgba(255,255,255,.045);
  --hero-grad: radial-gradient(120% 120% at 80% -10%, rgba(15,98,254,.30) 0%, rgba(15,98,254,0) 55%);
}
/* Light theme (Carbon white) */
html[data-theme="light"] {
  --bg:        #ffffff;
  --bg-2:      #f4f4f4;
  --layer:     #f4f4f4;
  --layer-2:   #e8e8e8;
  --layer-hover:#e8e8e8;
  --text:      #161616;
  --text-2:    #393939;
  --text-3:    #6f6f6f;
  --border:    #e0e0e0;
  --border-2:  #c6c6c6;
  --grid-line: rgba(0,0,0,.04);
  --hero-grad: radial-gradient(120% 120% at 80% -10%, rgba(15,98,254,.16) 0%, rgba(15,98,254,0) 55%);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  transition: background .4s var(--ease), color .4s var(--ease);
}
a { color: inherit; }
::selection { background: var(--blue); color: #fff; }

/* Scroll progress bar */
.progress {
  position: fixed; top: 0; left: 0; height: 3px; width: 0%;
  background: var(--blue); z-index: 100;
  transition: width .08s linear;
}

/* ===================== UI SHELL HEADER ===================== */
header.shell {
  position: sticky; top: 0; z-index: 80;
  display: flex; align-items: center; gap: var(--s4);
  height: 48px; padding: 0 var(--s5);
  background: var(--bg-2);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(6px);
}
/* small "back to all stories" link — far left of the header */
.shell .back-home {
  display: inline-flex; align-items: center; gap: 6px;
  font: 500 .76rem/1 var(--mono); text-decoration: none;
  color: var(--text-3);
  padding-right: var(--s4); margin-right: var(--s1);
  border-right: 1px solid var(--border);
  transition: color .2s;
}
.shell .back-home:hover { color: var(--text); }
.shell .back-home .bk-arr { transition: transform .2s var(--ease); }
.shell .back-home:hover .bk-arr { transform: translateX(-3px); }
@media (max-width: 520px) { .shell .back-home .bk-label { display: none; } }

.shell .brand {
  display: flex; align-items: center; gap: var(--s3);
  font: 600 .9rem/1 var(--sans); letter-spacing: .01em;
  color: inherit; text-decoration: none;
}
a.brand:hover .mark::before { background: var(--blue-2); }
a.brand:hover .mark::after  { background: var(--blue); }
.shell .brand .mark {
  width: 18px; height: 18px; position: relative; flex: none;
}
.shell .brand .mark::before,
.shell .brand .mark::after {
  content: ""; position: absolute; width: 8px; height: 8px; background: var(--blue);
}
.shell .brand .mark::before { top: 0; left: 0; }
.shell .brand .mark::after  { bottom: 0; right: 0; background: var(--blue-2); }
.shell .brand small { color: var(--text-3); font-weight: 400; font-family: var(--mono); font-size: .72rem; }
.shell nav { margin-left: auto; display: flex; gap: 2px; }
.shell nav a {
  text-decoration: none; color: var(--text-2); font-size: .82rem;
  padding: 0 var(--s3); height: 48px; display: inline-flex; align-items: center;
  border-bottom: 2px solid transparent; transition: color .2s, border-color .2s;
}
.shell nav a:hover { color: var(--text); border-bottom-color: var(--border-2); }
.shell nav a.active { color: var(--text); border-bottom-color: var(--blue); }
.theme-btn {
  appearance: none; cursor: pointer; height: 32px; padding: 0 var(--s3);
  display: inline-flex; align-items: center; gap: 6px;
  background: transparent; color: var(--text-2);
  border: 1px solid var(--border-2); font: 500 .76rem/1 var(--mono);
  transition: background .2s, color .2s, border-color .2s;
}
.theme-btn:hover { background: var(--layer); color: var(--text); border-color: var(--text-3); }
@media (max-width: 720px) { .shell nav { display: none; } }

/* ===================== LAYOUT ===================== */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 var(--s5); }
.section { padding: var(--s9) 0; }
.kicker {
  font: 500 .78rem/1 var(--mono); text-transform: uppercase; letter-spacing: .12em;
  color: var(--blue-2); display: inline-flex; align-items: center; gap: var(--s2);
  margin-bottom: var(--s4);
}
html[data-theme="light"] .kicker { color: var(--blue); }
.kicker::before { content: ""; width: 28px; height: 1px; background: currentColor; }
h2.head {
  font-size: clamp(1.8rem, 3.6vw, 2.8rem); font-weight: 400; line-height: 1.05;
  margin: 0 0 var(--s4); max-width: 22ch;
}
.lede { color: var(--text-2); max-width: 64ch; font-size: 1.08rem; margin: 0; }

/* ===================== HERO ===================== */
.hero {
  position: relative; overflow: hidden;
  background: var(--bg-2);
  border-bottom: 1px solid var(--border);
}
.hero .grid-bg {
  position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(180deg, #000 0%, transparent 92%);
}
.hero .glow { position: absolute; inset: 0; background: var(--hero-grad); pointer-events: none; }
.hero .wrap { position: relative; padding-top: var(--s9); padding-bottom: var(--s9); }
.hero .eyebrow {
  display: inline-flex; align-items: center; gap: var(--s2);
  font: 500 .8rem/1 var(--mono); letter-spacing: .06em;
  color: var(--text-2); border: 1px solid var(--border-2);
  padding: .4rem .65rem; margin-bottom: var(--s5);
}
.hero .eyebrow .dot { width: 7px; height: 7px; background: var(--green); border-radius: 50%; box-shadow: 0 0 0 0 rgba(66,190,101,.6); animation: pulse 2.4s infinite; }
@keyframes pulse { 0% { box-shadow: 0 0 0 0 rgba(66,190,101,.5);} 70% { box-shadow: 0 0 0 8px rgba(66,190,101,0);} 100% { box-shadow: 0 0 0 0 rgba(66,190,101,0);} }
.hero h1 {
  margin: 0; font-weight: 300; line-height: 1.0;
  font-size: clamp(2.6rem, 7vw, 5.4rem); letter-spacing: -.02em; max-width: 16ch;
}
.hero h1 b { font-weight: 600; }
.hero h1 .accent {
  background: linear-gradient(90deg, var(--blue-2), var(--purple));
  -webkit-background-clip: text; background-clip: text; color: transparent; font-weight: 600;
}
.hero p.sub { margin: var(--s5) 0 0; max-width: 60ch; color: var(--text-2); font-size: 1.15rem; }
.hero .cta { display: flex; gap: var(--s3); flex-wrap: wrap; margin-top: var(--s6); }
.btn {
  display: inline-flex; align-items: center; gap: var(--s4);
  font: 400 1rem/1 var(--sans); cursor: pointer; text-decoration: none;
  padding: .9rem 1.1rem; border: 1px solid transparent; transition: background .2s, border-color .2s, transform .15s;
}
.btn .arr { transition: transform .2s var(--ease); }
.btn:hover .arr { transform: translateX(4px); }
.btn.primary { background: var(--blue); color: #fff; }
.btn.primary:hover { background: #0353e9; }
.btn.ghost { background: transparent; color: var(--text); border-color: var(--border-2); }
.btn.ghost:hover { border-color: var(--text); background: var(--layer); }

.hero .stats { display: grid; grid-template-columns: repeat(3, max-content); gap: var(--s7); margin-top: var(--s8); }
.hero .stats .stat .n { font: 600 2.2rem/1 var(--sans); letter-spacing: -.02em; }
.hero .stats .stat .l { color: var(--text-3); font: 500 .76rem/1.3 var(--mono); text-transform: uppercase; letter-spacing: .06em; margin-top: var(--s2); }
@media (max-width: 560px) { .hero .stats { gap: var(--s5); } .hero .stats .stat .n { font-size: 1.7rem; } }

/* ===================== SCROLL-DRIVEN STORY ===================== */
.story { background: var(--bg); }
.story .layout { display: grid; grid-template-columns: 320px 1fr; gap: var(--s8); align-items: start; }

/* sticky scene stepper */
.stepper { position: sticky; top: 96px; display: grid; gap: 2px; }
.stepper .stp {
  display: grid; grid-template-columns: 34px 1fr; align-items: center; gap: var(--s3);
  padding: var(--s3) var(--s3); border-left: 2px solid var(--border);
  color: var(--text-3); cursor: pointer; transition: color .25s, border-color .25s, background .25s;
  text-decoration: none;
}
.stepper .stp .idx { font: 500 .8rem/1 var(--mono); width: 34px; height: 34px; display: grid; place-items: center; border: 1px solid var(--border); transition: all .25s; }
.stepper .stp .ttl { font-size: .92rem; }
.stepper .stp:hover { color: var(--text-2); }
.stepper .stp.active { color: var(--text); border-left-color: var(--accent); background: var(--layer); }
.stepper .stp.active .idx { border-color: var(--accent); color: #fff; background: var(--accent); }

.scenes { display: grid; gap: var(--s6); }
.scene {
  position: relative; background: var(--layer); border: 1px solid var(--border);
  padding: var(--s7); overflow: hidden;
  opacity: 0; transform: translateY(28px); transition: opacity .7s var(--ease), transform .7s var(--ease), border-color .3s;
}
.scene.in { opacity: 1; transform: none; }
.scene::before { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 4px; background: var(--accent); }
.scene .big-no {
  position: absolute; right: var(--s5); top: var(--s4); font: 600 clamp(4rem, 10vw, 8rem)/1 var(--sans);
  color: var(--text); opacity: .045; letter-spacing: -.04em; user-select: none;
}
.scene .role {
  display: inline-flex; align-items: center; gap: var(--s2);
  font: 500 .74rem/1 var(--mono); text-transform: uppercase; letter-spacing: .08em;
  color: var(--accent); padding: .35rem .55rem; border: 1px solid var(--border-2);
  margin-bottom: var(--s4);
}
.scene h3 { font-size: clamp(1.4rem, 2.6vw, 1.9rem); font-weight: 400; margin: 0 0 var(--s3); max-width: 22ch; }
.scene p { color: var(--text-2); margin: 0; max-width: 60ch; font-size: 1.05rem; }
.scene .meta { display: flex; gap: var(--s2); flex-wrap: wrap; margin-top: var(--s5); }
.scene .chip { font: 500 .74rem/1 var(--mono); color: var(--text-2); background: var(--bg); border: 1px solid var(--border); padding: .4rem .55rem; }

@media (max-width: 920px) {
  .story .layout { grid-template-columns: 1fr; gap: var(--s5); }
  .stepper { position: static; grid-auto-flow: column; overflow-x: auto; padding-bottom: var(--s2); }
  .stepper .stp { border-left: none; border-top: 2px solid var(--border); min-width: 200px; }
  .stepper .stp.active { border-top-color: var(--accent); }
}

/* ===================== SPLIT: NARRATION + QUOTE ===================== */
.split { display: grid; grid-template-columns: 1.25fr .75fr; gap: var(--s6); }
.card { background: var(--layer); border: 1px solid var(--border); padding: var(--s7); }
.timeline { display: grid; gap: 0; margin-top: var(--s4); }
.ti { display: grid; grid-template-columns: 120px 1fr; gap: var(--s5); padding: var(--s5) 0; border-top: 1px solid var(--border); }
.ti:first-child { border-top: none; padding-top: var(--s2); }
.ti .lab { font: 500 .76rem/1.4 var(--mono); text-transform: uppercase; letter-spacing: .06em; color: var(--text-3); }
.ti h4 { margin: 0 0 var(--s2); font-size: 1.1rem; font-weight: 500; }
.ti p { margin: 0; color: var(--text-2); }
.quote {
  display: flex; flex-direction: column; justify-content: center;
  background: linear-gradient(160deg, var(--layer) 0%, var(--bg-2) 100%);
  border-left: 4px solid var(--blue);
}
.quote .qmark { font: 600 4rem/0.6 var(--sans); color: var(--blue-2); }
.quote p { font-size: 1.25rem; line-height: 1.45; margin: var(--s4) 0; font-weight: 300; }
.quote .by { color: var(--text-3); font: 500 .78rem/1 var(--mono); text-transform: uppercase; letter-spacing: .08em; }
@media (max-width: 920px) { .split { grid-template-columns: 1fr; } .ti { grid-template-columns: 1fr; gap: var(--s2); } }

/* full-width statement band */
.statement .quote { padding: var(--s8) var(--s8); }
.statement .quote p { font-size: clamp(1.4rem, 3vw, 2.1rem); line-height: 1.3; max-width: 34ch; }
@media (max-width: 560px) { .statement .quote { padding: var(--s6) var(--s5); } }

/* ===================== PERSONAS ===================== */
.personas { display: grid; grid-template-columns: repeat(5, 1fr); gap: var(--s4); }
.persona {
  background: var(--layer); border: 1px solid var(--border); padding: var(--s5);
  transition: transform .25s var(--ease), border-color .25s, background .25s;
}
.persona:hover { transform: translateY(-4px); border-color: var(--accent); }
.persona .ic {
  width: 44px; height: 44px; display: grid; place-items: center; font-size: 1.3rem;
  background: var(--bg); border: 1px solid var(--border); margin-bottom: var(--s4);
}
.persona:hover .ic { border-color: var(--accent); }
.persona strong { display: block; font-size: 1rem; font-weight: 500; margin-bottom: var(--s1); }
.persona span { display: block; color: var(--text-3); font-size: .88rem; }
.persona .tag { display: inline-block; margin-top: var(--s4); font: 500 .68rem/1 var(--mono); color: var(--accent); }
@media (max-width: 920px) { .personas { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 480px) { .personas { grid-template-columns: 1fr; } }

/* ===================== OUTCOMES ===================== */
.outcomes { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--s5); }
.outcome { background: var(--layer); border: 1px solid var(--border); padding: var(--s7); position: relative; }
.outcome::before { content: ""; position: absolute; left: 0; top: 0; width: 100%; height: 4px; background: var(--accent); }
.outcome .num { font: 600 3rem/1 var(--sans); letter-spacing: -.02em; color: var(--text); }
.outcome h3 { font-size: 1.15rem; font-weight: 500; margin: var(--s4) 0 var(--s2); }
.outcome p { margin: 0; color: var(--text-2); }
@media (max-width: 920px) { .outcomes { grid-template-columns: 1fr; } }

/* ===================== CTA BANNER ===================== */
.banner {
  background: var(--blue); color: #fff; position: relative; overflow: hidden;
}
.banner .grid-bg {
  position: absolute; inset: 0;
  background-image: linear-gradient(rgba(255,255,255,.06) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.06) 1px, transparent 1px);
  background-size: 40px 40px;
}
.banner .wrap { position: relative; display: flex; align-items: center; justify-content: space-between; gap: var(--s6); flex-wrap: wrap; padding: var(--s8) var(--s5); }
.banner h2 { font-size: clamp(1.6rem, 3vw, 2.4rem); font-weight: 400; margin: 0; max-width: 18ch; }
.banner .btn.primary { background: #fff; color: var(--blue); }
.banner .btn.primary:hover { background: #e8e8e8; }

/* ===================== FOOTER ===================== */
footer.foot { border-top: 1px solid var(--border); background: var(--bg-2); }
footer.foot .wrap { display: flex; justify-content: space-between; align-items: center; gap: var(--s4); flex-wrap: wrap; padding: var(--s6) var(--s5); color: var(--text-3); font-size: .9rem; }
footer.foot .foot-slogan { color: var(--text-2); font-size: 1.02rem; max-width: 52ch; }
footer.foot .foot-slogan strong { color: var(--text); font-weight: 600; }
footer.foot .foot-meta { font: 500 .74rem/1.4 var(--mono); text-transform: uppercase; letter-spacing: .06em; color: var(--text-3); }
footer.foot .foot-end { display: flex; flex-direction: column; align-items: flex-end; gap: var(--s3); }
footer.foot .foot-cta {
  display: inline-flex; align-items: center; gap: 7px; white-space: nowrap;
  font: 500 .82rem/1 var(--sans); text-decoration: none; color: var(--text);
  padding: .5rem .7rem; border: 1px solid var(--border-2);
  transition: background .2s, border-color .2s, color .2s;
}
footer.foot .foot-cta:hover { background: var(--layer); border-color: var(--text); }
footer.foot .foot-cta .ext { width: 13px; height: 13px; transition: transform .2s var(--ease); }
footer.foot .foot-cta:hover .ext { transform: translate(2px, -2px); }
@media (max-width: 560px) { footer.foot .foot-end { align-items: flex-start; } }

/* reveal utility */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; scroll-behavior: auto; }
  .reveal, .scene { opacity: 1 !important; transform: none !important; }
}