/* ==========================================================================
   EDU.FYI — New Student Tutorial
   Brand tokens carried over from BRAND.md §3–4 (black + blue #2777f3 +
   yellow #eabc30, SF Pro system stack with Inter fallback, sharp logo).
   ========================================================================== */
:root{
  --black:#000000;
  --white:#ffffff;
  --gray:#868e96;
  --blue-1:#1651aa;
  --blue-2:#2777f3;
  --yellow:#eabc30;
  --surface:rgba(255,255,255,.05);
  --surface-strong:rgba(255,255,255,.08);
  --hairline:rgba(134,142,150,.28);
  --radius-sm:8px;
  --radius-md:14px;
  --radius-lg:22px;
  --radius-full:999px;
  --radius-btn:14px;
  --font-heading:-apple-system,"SF Pro Display",system-ui,Inter,sans-serif;
  --font-body:-apple-system,"SF Pro Text",system-ui,Inter,sans-serif;
  --container:1240px;
  --ease:cubic-bezier(.2,.7,.2,1);
  --header-h:76px;
  --progress-h:4px;
}

*,*::before,*::after{box-sizing:border-box;}
html{scroll-behavior:smooth;scroll-padding-top:calc(var(--header-h) + var(--progress-h) + 20px);}
body{
  margin:0;
  background:var(--black);
  color:var(--white);
  font-family:var(--font-body);
  font-weight:400;
  line-height:1.55;
  -webkit-font-smoothing:antialiased;
}
img,svg{display:block;max-width:100%;}
a{color:inherit;}
h1,h2,h3,h4{
  font-family:var(--font-heading);
  font-weight:700;
  line-height:1.14;
  margin:0 0 .4em;
  letter-spacing:-.015em;
}
p{margin:0 0 .8em;color:rgba(255,255,255,.82);}
ul,ol{margin:0;padding:0;list-style:none;}
button{font-family:inherit;}
strong{color:#fff;font-weight:600;}

.sr-only{
  position:absolute;width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0;
}
.skip-link{
  position:fixed;left:-999px;top:0;background:var(--blue-2);color:#fff;
  padding:10px 16px;border-radius:0 0 var(--radius-sm) 0;z-index:400;font-weight:600;
}
.skip-link:focus{left:0;}
:focus-visible{outline:2px solid var(--yellow);outline-offset:3px;border-radius:4px;}

.container{width:100%;max-width:var(--container);margin:0 auto;padding:0 24px;}
.text-accent{color:var(--yellow);}
.text-blue{color:var(--blue-2);}

/* ===== Buttons ===== */
.btn{
  display:inline-flex;align-items:center;gap:9px;
  padding:13px 22px;border-radius:var(--radius-btn);
  font-family:var(--font-heading);font-weight:600;font-size:15px;
  text-decoration:none;border:1.5px solid transparent;cursor:pointer;
  transition:transform .18s var(--ease),box-shadow .18s var(--ease),border-color .18s var(--ease),color .18s var(--ease),background .18s var(--ease);
  white-space:nowrap;
}
.btn .icon{fill:currentColor;flex-shrink:0;}
.btn-primary{
  background:linear-gradient(135deg,var(--blue-2),var(--blue-1));
  color:#fff;box-shadow:0 10px 26px rgba(39,119,243,.32);
}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 14px 32px rgba(39,119,243,.44);}
.btn-outline{background:transparent;color:#fff;border-color:rgba(255,255,255,.32);}
.btn-outline:hover{border-color:var(--blue-2);color:var(--blue-2);}
.btn-ghost{background:var(--surface);color:#fff;border-color:var(--hairline);}
.btn-ghost:hover:not([disabled]){border-color:var(--blue-2);background:var(--surface-strong);}
.btn-sm{padding:9px 15px;font-size:13px;}
.btn-lg{padding:16px 28px;font-size:16px;}
.btn[disabled]{opacity:.4;cursor:not-allowed;}

/* ===== Section-title speech bubbles (Figma SVGs in assets/labels/*.svg) ===== */
.bubble-label-img{display:block;height:clamp(46px,4.6vw,58px);width:auto;margin-bottom:16px;}

/* ==========================================================================
   Top progress bar (fixed, fills as you advance)
   ========================================================================== */
.progress-track{
  position:fixed;top:0;left:0;right:0;height:var(--progress-h);
  background:rgba(255,255,255,.07);z-index:210;
}
.progress-fill{
  height:100%;width:0%;
  background:linear-gradient(90deg,var(--blue-2),var(--yellow));
  box-shadow:0 0 12px rgba(39,119,243,.5);
  transition:width .25s var(--ease);
}

/* ==========================================================================
   Header
   ========================================================================== */
.site-header{
  position:sticky;top:var(--progress-h);z-index:200;
  height:var(--header-h);
  background:var(--black);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--hairline);
}
.header-inner{display:flex;align-items:center;justify-content:space-between;gap:16px;height:100%;}
.brand-lockup{display:inline-flex;align-items:center;gap:12px;text-decoration:none;}
.brand-lockup .logo{height:40px;width:auto;}
.brand-tag{
  font-family:var(--font-heading);font-weight:600;font-size:13px;letter-spacing:.02em;
  color:rgba(255,255,255,.68);padding-left:12px;border-left:1px solid var(--hairline);
}
.header-actions{display:flex;align-items:center;gap:10px;}
.rail-toggle{
  display:none;align-items:center;gap:8px;
  padding:8px 14px;border-radius:var(--radius-btn);
  background:var(--surface);border:1px solid var(--hairline);color:#fff;
  font-family:var(--font-heading);font-weight:600;font-size:13px;cursor:pointer;
}
.rail-toggle .step-of{color:var(--blue-2);}

/* ==========================================================================
   Layout: sticky chapter rail + main content
   ========================================================================== */
.tutorial-layout{
  display:grid;
  grid-template-columns:280px minmax(0,1fr);
  gap:48px;
  align-items:start;
  padding-top:40px;padding-bottom:40px;
}

/* ---- Chapter rail (vertical stepper) ---- */
.chapter-rail{
  position:sticky;
  top:calc(var(--header-h) + var(--progress-h) + 28px);
  align-self:start;
}
.rail-head{display:flex;align-items:baseline;justify-content:space-between;margin-bottom:6px;}
.rail-head h2{font-size:13px;text-transform:uppercase;letter-spacing:.1em;color:var(--gray);margin:0;}
.rail-count{font-size:13px;color:var(--blue-2);font-weight:600;font-variant-numeric:tabular-nums;}
.rail-progressbar{height:5px;border-radius:var(--radius-full);background:rgba(255,255,255,.08);overflow:hidden;margin:10px 0 18px;}
.rail-progressbar span{display:block;height:100%;width:0%;background:linear-gradient(90deg,var(--blue-2),var(--yellow));transition:width .3s var(--ease);}

.rail-list{position:relative;}
.rail-list li{position:relative;}
.rail-link{
  display:grid;grid-template-columns:30px 1fr;align-items:center;gap:12px;
  padding:8px 10px;border-radius:var(--radius-sm);
  text-decoration:none;color:rgba(255,255,255,.66);
  font-size:14px;line-height:1.3;
  transition:background .15s var(--ease),color .15s var(--ease);
}
.rail-link:hover{background:var(--surface);color:#fff;}
.rail-dot{
  position:relative;z-index:1;
  width:30px;height:30px;border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  background:#0a0a0a;border:1.5px solid var(--hairline);
  font-family:var(--font-heading);font-weight:600;font-size:13px;color:var(--gray);
  font-variant-numeric:tabular-nums;
  transition:all .2s var(--ease);
}
.rail-dot .check{display:none;width:15px;height:15px;}
/* connector line between dots */
.rail-list li:not(:last-child) .rail-link::before{
  content:"";position:absolute;left:24px;top:32px;bottom:-8px;width:2px;
  background:var(--hairline);z-index:0;
}
.rail-list li.is-done:not(:last-child) .rail-link::before{background:var(--blue-2);}

.rail-list li.is-done .rail-dot{background:var(--blue-2);border-color:var(--blue-2);color:#fff;}
.rail-list li.is-done .rail-dot .num{display:none;}
.rail-list li.is-done .rail-dot .check{display:block;}
.rail-list li.is-active .rail-link{color:#fff;background:var(--surface);}
.rail-list li.is-active .rail-dot{
  border-color:var(--yellow);color:#fff;
  box-shadow:0 0 0 4px rgba(234,188,48,.16);
}
.rail-list li.is-active.is-done .rail-dot{background:var(--blue-2);border-color:var(--yellow);}
.rail-label{font-family:var(--font-heading);font-weight:500;}
.rail-list li.is-active .rail-label{font-weight:600;}

.rail-reset{
  margin-top:18px;width:100%;
  padding:9px 12px;border-radius:var(--radius-sm);
  background:transparent;border:1px solid var(--hairline);color:var(--gray);
  font-size:12.5px;font-weight:500;cursor:pointer;
  transition:color .15s var(--ease),border-color .15s var(--ease);
}
.rail-reset:hover{color:#fff;border-color:var(--blue-2);}

/* ==========================================================================
   Chapters
   ========================================================================== */
.chapter{
  position:relative;
  scroll-margin-top:calc(var(--header-h) + var(--progress-h) + 24px);
  padding:44px 0;
  border-top:1px solid var(--hairline);
}
.chapter:first-of-type{border-top:none;padding-top:8px;}
.chapter-grid{
  display:grid;grid-template-columns:1fr;gap:34px;align-items:center;
}
@media (min-width:820px){
  .chapter--split .chapter-grid{grid-template-columns:1.02fr .98fr;gap:44px;}
  /* Alternate the media side for rhythm */
  .chapter--split.chapter--media-left .chapter-copy{order:2;}
  .chapter--split.chapter--media-left .chapter-media{order:1;}
}
.chapter-kicker{
  display:inline-flex;align-items:center;gap:8px;
  font-family:var(--font-heading);font-size:12px;font-weight:600;
  letter-spacing:.11em;text-transform:uppercase;color:var(--blue-2);
  margin-bottom:14px;
}
.chapter-kicker .k-num{
  display:inline-flex;align-items:center;justify-content:center;
  min-width:22px;height:22px;padding:0 6px;border-radius:var(--radius-full);
  background:rgba(39,119,243,.16);color:var(--blue-2);font-variant-numeric:tabular-nums;
}
.chapter h2{font-size:clamp(1.55rem,3vw,2.3rem);max-width:22ch;margin-bottom:.35em;}
.chapter .lead{font-size:17.5px;color:rgba(255,255,255,.88);line-height:1.5;margin-bottom:1em;}
.chapter p{font-size:15.5px;}

/* Numbered how-to steps */
.steps{display:grid;gap:12px;margin:18px 0 8px;counter-reset:step;}
.steps li{
  position:relative;display:grid;grid-template-columns:30px 1fr;gap:14px;align-items:start;
  padding:14px 16px;background:var(--surface);border:1px solid var(--hairline);
  border-radius:var(--radius-md);
  transition:border-color .2s var(--ease),background .2s var(--ease);
}
.steps li:hover{border-color:rgba(39,119,243,.42);background:var(--surface-strong);}
.steps li::before{
  counter-increment:step;content:counter(step);
  width:30px;height:30px;border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  background:linear-gradient(135deg,var(--blue-2),var(--blue-1));color:#fff;
  font-family:var(--font-heading);font-weight:600;font-size:14px;font-variant-numeric:tabular-nums;
}
.steps li p{margin:0;font-size:15px;color:rgba(255,255,255,.86);padding-top:3px;}
.steps li strong{font-weight:600;}

/* Definition list (categories, abilities) */
.def-list{display:grid;gap:10px;margin:16px 0;}
.def-list li{padding:12px 16px;background:var(--surface);border:1px solid var(--hairline);border-radius:var(--radius-sm);font-size:15px;}
.def-list b{color:var(--yellow);font-family:var(--font-heading);font-weight:600;}

/* Chip list (abilities, feature tags) */
.chip-list{display:flex;flex-wrap:wrap;gap:8px;margin:14px 0 4px;}
.chip-list li{
  padding:7px 14px;border-radius:var(--radius-full);border:1px solid var(--hairline);
  font-size:13px;color:rgba(255,255,255,.86);background:var(--surface);
}
.chip-list li .dot{display:inline-block;width:6px;height:6px;border-radius:50%;background:var(--blue-2);margin-right:8px;vertical-align:middle;}

/* ===== Abilities guide ===== */
.ability-guide{
  margin-top:42px;padding-top:34px;border-top:1px dashed var(--hairline);
}
.ability-guide-head{max-width:720px;margin-bottom:22px;}
.ability-guide-head .chapter-kicker{margin-bottom:10px;}
.ability-guide-head h3{font-size:clamp(1.4rem,2.6vw,2rem);margin-bottom:.4em;}
.ability-guide-head p{font-size:15px;color:rgba(255,255,255,.74);margin:0;}
.ability-category-grid{display:grid;grid-template-columns:1fr;gap:16px;}
@media (min-width:760px){
  .ability-category-grid{grid-template-columns:repeat(2,minmax(0,1fr));}
}
.ability-category{
  padding:20px;background:var(--surface);border:1px solid var(--hairline);
  border-radius:var(--radius-lg);
  transition:border-color .2s var(--ease),transform .2s var(--ease);
}
.ability-category:hover{border-color:rgba(39,119,243,.5);transform:translateY(-2px);}
.ability-category-head{display:flex;gap:13px;align-items:flex-start;margin-bottom:14px;}
.ability-category-number{
  display:inline-flex;align-items:center;justify-content:center;flex:0 0 auto;
  min-width:34px;height:26px;padding:0 8px;border-radius:var(--radius-full);
  background:rgba(39,119,243,.16);color:var(--blue-2);
  font-family:var(--font-heading);font-size:11px;font-weight:700;letter-spacing:.06em;
}
.ability-category-head h4{font-size:17px;margin:1px 0 4px;}
.ability-category-head p{font-size:13.5px;color:rgba(255,255,255,.64);margin:0;}

/* Swipable diagonal deck of ability screens (chapter 8 media). */
.ability-deck{display:flex;flex-direction:column;align-items:center;gap:16px;width:100%;}
.ability-deck__stack{
  position:relative;width:100%;max-width:330px;margin:0 auto;
  height:512px;
  touch-action:pan-y;-webkit-user-select:none;user-select:none;
}
.ability-deck__stack::before{
  content:"";position:absolute;inset:6% 8% 12%;
  background:radial-gradient(closest-side,rgba(39,119,243,.22),rgba(39,119,243,0) 72%);
  filter:blur(56px);pointer-events:none;
}
.ability-deck__stack .ability-slide{
  position:absolute;top:0;left:50%;width:min(74%,228px);
  transform:translateX(-50%);transform-origin:center bottom;
  cursor:grab;will-change:transform,opacity;
  transition:transform .5s cubic-bezier(.2,.7,.2,1),opacity .45s var(--ease);
}
.ability-deck__stack .ability-slide:active{cursor:grabbing;}
.ability-slide img{pointer-events:none;}
.ability-deck__caption{
  margin:0;font-family:var(--font-heading);font-size:13px;font-weight:600;
  letter-spacing:.02em;color:rgba(255,255,255,.82);text-align:center;min-height:1.2em;
}
.ability-deck__caption b{color:var(--blue-2);font-weight:700;}
.ability-deck__dots{display:flex;gap:9px;justify-content:center;}
.ability-deck__dots button{
  width:8px;height:8px;padding:0;border:0;border-radius:var(--radius-full);
  background:rgba(255,255,255,.24);cursor:pointer;
  transition:background .2s var(--ease),transform .2s var(--ease);
}
.ability-deck__dots button:hover{background:rgba(255,255,255,.5);}
.ability-deck__dots button[aria-selected="true"]{background:var(--blue-2);transform:scale(1.35);}
.ability-list{display:grid;}
.ability-list li{padding:12px 0;border-top:1px solid var(--hairline);}
.ability-list strong{display:flex;align-items:center;flex-wrap:wrap;gap:8px;font-family:var(--font-heading);font-size:14.5px;margin-bottom:3px;}
.ability-list span{display:block;font-size:13.5px;line-height:1.48;color:rgba(255,255,255,.7);}
.ability-list strong .coming-soon{display:inline-flex;font-size:10px;line-height:1;color:var(--yellow);}

/* Coming soon pill — yellow accent per BRAND.md, pill radius + heading caps */
.coming-soon{
  display:inline-flex;align-items:center;gap:5px;vertical-align:middle;
  padding:3px 9px;border-radius:var(--radius-full);
  font-family:var(--font-heading);font-size:10px;font-weight:700;
  letter-spacing:.07em;text-transform:uppercase;white-space:nowrap;line-height:1;
  color:var(--yellow);background:rgba(234,188,48,.14);
  border:1px solid rgba(234,188,48,.34);
}
.coming-soon::before{content:"";width:5px;height:5px;border-radius:50%;background:var(--yellow);}
.ability-prompts{
  margin-top:18px;padding:20px;background:rgba(39,119,243,.08);
  border:1px solid rgba(39,119,243,.3);border-radius:var(--radius-lg);
}
.ability-prompts h4{font-size:15px;margin-bottom:14px;color:#fff;}
.ability-prompt-grid{display:grid;grid-template-columns:1fr;gap:10px;}
@media (min-width:760px){
  .ability-prompt-grid{grid-template-columns:repeat(2,minmax(0,1fr));}
}
.ability-prompt-grid article{
  padding:16px;background:rgba(0,0,0,.28);
  border:1px solid var(--hairline);border-radius:var(--radius-sm);
  transition:transform .2s var(--ease),border-color .2s var(--ease),background .2s var(--ease);
}
.ability-prompt-grid article:hover{
  transform:translateY(-2px);border-color:rgba(39,119,243,.45);
  background:rgba(39,119,243,.06);
}
.ability-prompt-grid article > span{
  display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-bottom:8px;color:var(--blue-2);
  font-family:var(--font-heading);font-size:11px;font-weight:700;
  letter-spacing:.06em;text-transform:uppercase;
}
.ability-prompt-request{
  position:relative;margin:0;padding-left:13px;font-size:14px;line-height:1.5;
  color:rgba(255,255,255,.9);font-weight:500;
}
.ability-prompt-request::before{
  content:"";position:absolute;left:0;top:3px;bottom:3px;width:3px;
  border-radius:var(--radius-full);background:rgba(39,119,243,.55);
}

/* Coming soon items recede vs available ones (no extra markup via :has) */
.ability-list li:has(.coming-soon) strong{color:rgba(255,255,255,.74);}
.ability-list li:has(.coming-soon) span{color:rgba(255,255,255,.52);}
.ability-prompt-grid article:has(.coming-soon){
  border-color:rgba(234,188,48,.26);
  background:linear-gradient(rgba(234,188,48,.05),rgba(0,0,0,.28));
}
.ability-prompt-grid article:has(.coming-soon):hover{
  border-color:rgba(234,188,48,.45);background:rgba(234,188,48,.08);
}
.ability-prompt-grid article:has(.coming-soon) .ability-prompt-request{color:rgba(255,255,255,.7);}
.ability-prompt-grid article:has(.coming-soon) .ability-prompt-request::before{background:rgba(234,188,48,.55);}

/* ===== Agent in chats guide ===== */
.chat-guide-grid{display:grid;grid-template-columns:1fr;gap:16px;margin-top:24px;}
@media (min-width:820px){
  .chat-guide-grid{grid-template-columns:minmax(0,1.25fr) minmax(280px,.75fr);}
}
.chat-settings{display:grid;gap:16px;}
.chat-guide-card{
  padding:20px;background:var(--surface);border:1px solid var(--hairline);
  border-radius:var(--radius-lg);
}
.chat-guide-card--primary{
  background:linear-gradient(180deg,rgba(39,119,243,.13),rgba(39,119,243,.04));
  border-color:rgba(39,119,243,.4);
}
.chat-guide-label,.chat-action-tag{
  display:inline-block;margin-bottom:8px;color:var(--blue-2);
  font-family:var(--font-heading);font-size:11px;font-weight:700;
  letter-spacing:.07em;text-transform:uppercase;
}
.chat-guide-card h3{font-size:18px;margin-bottom:.45em;}
.chat-guide-card > p{font-size:14px;color:rgba(255,255,255,.74);margin:0;}
.chat-guide-card .steps{margin:14px 0 0;}
.chat-guide-card .steps li{background:rgba(0,0,0,.2);}
.chat-usage{
  margin-top:18px;padding:22px;background:var(--surface);
  border:1px solid var(--hairline);border-radius:var(--radius-lg);
}
.chat-usage > h3{font-size:19px;margin-bottom:16px;}
.chat-action-grid{display:grid;grid-template-columns:1fr;gap:12px;}
@media (min-width:700px){
  .chat-action-grid{grid-template-columns:repeat(2,minmax(0,1fr));}
}
.chat-action-grid article{
  padding:16px;background:rgba(0,0,0,.28);
  border:1px solid var(--hairline);border-radius:var(--radius-md);
}
.chat-action-grid h4{font-size:15px;margin-bottom:.35em;}
.chat-action-grid p{font-size:13.5px;color:rgba(255,255,255,.72);margin:0;}
.chat-action-grid p strong{font-weight:500;color:rgba(255,255,255,.9);}

/* ===== Guided-tour coach marks (mirrors the in-app tooltips) ===== */
.tour-list{display:grid;gap:12px;margin:16px 0 6px;}
.coach{
  position:relative;
  padding:14px 16px;
  background:linear-gradient(180deg,rgba(39,119,243,.16),rgba(39,119,243,.05));
  border:1px solid rgba(39,119,243,.4);
  border-radius:var(--radius-md);
}
.coach::before{
  content:"";position:absolute;left:18px;top:-6px;width:11px;height:11px;
  background:rgba(39,119,243,.32);
  border-left:1px solid rgba(39,119,243,.4);border-top:1px solid rgba(39,119,243,.4);
  transform:rotate(45deg);
}
.coach-step{
  display:inline-flex;align-items:center;gap:7px;
  font-family:var(--font-heading);font-weight:600;font-size:12.5px;
  letter-spacing:.02em;color:var(--blue-2);margin-bottom:5px;
}
.coach-step svg{fill:currentColor;flex-shrink:0;}
.coach p{margin:0;font-size:14.5px;color:rgba(255,255,255,.85);}

/* ===== "App at a glance" nav map ===== */
.app-map{
  margin:20px 0 6px;padding:16px 18px;
  background:var(--surface);border:1px solid var(--hairline);border-radius:var(--radius-md);
}
.app-map h4{font-size:12px;text-transform:uppercase;letter-spacing:.1em;color:var(--gray);margin:0 0 12px;}
.app-nav{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;}
.app-nav .tab{
  display:flex;flex-direction:column;align-items:center;gap:6px;
  padding:12px 6px;border-radius:var(--radius-sm);
  background:rgba(255,255,255,.03);border:1px solid var(--hairline);
  font-family:var(--font-heading);font-weight:600;font-size:12px;color:rgba(255,255,255,.7);
  text-align:center;
}
.app-nav .tab .ic{width:22px;height:22px;color:var(--gray);}
.app-nav .tab.is-primary{background:rgba(39,119,243,.14);border-color:rgba(39,119,243,.5);color:#fff;}
.app-nav .tab.is-primary .ic{color:var(--blue-2);}
.map-note{margin:12px 0 0;font-size:13.5px;color:rgba(255,255,255,.72);}
.map-note b{color:#fff;}

/* Good-to-know callout */
.callout{
  display:grid;grid-template-columns:auto 1fr;gap:14px;align-items:start;
  margin-top:18px;padding:16px 18px;
  background:rgba(234,188,48,.07);
  border:1px solid rgba(234,188,48,.32);
  border-left:3px solid var(--yellow);
  border-radius:0 var(--radius-md) var(--radius-md) 0;
}
.callout .callout-icon{
  width:30px;height:30px;border-radius:8px;flex-shrink:0;
  display:flex;align-items:center;justify-content:center;
  background:rgba(234,188,48,.16);color:var(--yellow);
}
.callout h4{font-size:13px;text-transform:uppercase;letter-spacing:.06em;color:var(--yellow);margin:0 0 4px;}
.callout p{margin:0;font-size:14.5px;color:rgba(255,255,255,.82);}

/* ===== Phone screenshots (2x renders, device frame baked in) ===== */
.chapter-media{position:relative;}
.phone-shot{position:relative;display:flex;justify-content:center;}
.phone-shot::before{
  content:"";position:absolute;inset:4% 8%;
  background:radial-gradient(closest-side,rgba(39,119,243,.2),rgba(39,119,243,0) 72%);
  filter:blur(50px);pointer-events:none;
}
.phone-shot img{
  position:relative;
  width:auto;height:auto;
  max-width:min(100%,430px);
  max-height:min(80vh,720px);
  filter:drop-shadow(0 28px 56px rgba(0,0,0,.55));
}
.phone-shot--wide img{max-width:min(100%,480px);}
.framed{
  position:relative;background:rgba(255,255,255,.03);
  border:1px solid rgba(255,255,255,.08);border-radius:var(--radius-lg);
  padding:12px;box-shadow:0 16px 40px rgba(0,0,0,.3);overflow:hidden;
}
.framed img{width:100%;height:auto;border-radius:var(--radius-md);}

/* CSS device frame — for raw, frameless screen captures (pure-black bg) so
   they read as a phone and sit cleanly against the black page. */
.device{
  position:relative;border-radius:34px;background:#0a0a0c;padding:7px;
  border:1px solid rgba(255,255,255,.1);
  box-shadow:0 30px 60px rgba(0,0,0,.6),inset 0 0 0 1px rgba(255,255,255,.03);
}
.device img{display:block;width:100%;height:auto;border-radius:28px;}

/* Chats intro — section copy beside a live chat screenshot. */
.chat-intro{display:grid;grid-template-columns:1fr;gap:26px;align-items:center;margin-bottom:34px;}
@media (min-width:820px){
  .chat-intro{grid-template-columns:1.15fr .85fr;gap:48px;}
}
.chat-intro__copy{min-width:0;}
.chat-intro__media{position:relative;display:flex;justify-content:center;}
.chat-intro__media::before{
  content:"";position:absolute;inset:4% 8%;
  background:radial-gradient(closest-side,rgba(39,119,243,.22),rgba(39,119,243,0) 72%);
  filter:blur(56px);pointer-events:none;
}
.chat-intro__media .device{position:relative;width:min(100%,256px);}

/* ===== Per-chapter Back / Next nav ===== */
.chapter-nav{
  display:flex;align-items:center;justify-content:space-between;gap:14px;
  margin-top:32px;padding-top:22px;border-top:1px dashed var(--hairline);
}
.chapter-nav .spacer{flex:1;}
.chapter-nav .btn{min-width:112px;justify-content:center;}
.nav-hint{font-size:12.5px;color:var(--gray);text-align:center;}

/* ==========================================================================
   Hero (chapter 1)
   ========================================================================== */
.hero-chapter{padding-top:16px;}
.hero-eyebrow{margin-bottom:16px;}
.hero-chapter h1{font-size:clamp(2rem,4.4vw,3.2rem);max-width:16ch;margin-bottom:.4em;}
.hero-chapter .lead{font-size:18.5px;max-width:60ch;}
.hero-cta{display:flex;flex-wrap:wrap;gap:12px;margin:22px 0 6px;}
.checklist{display:grid;gap:10px;margin:8px 0 4px;}
.checklist li{display:grid;grid-template-columns:24px 1fr;gap:12px;align-items:start;font-size:15.5px;color:rgba(255,255,255,.88);}
.checklist li .tick{
  width:24px;height:24px;border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  background:rgba(39,119,243,.16);color:var(--blue-2);flex-shrink:0;
}
.how-note{
  margin-top:18px;padding:14px 16px;border-radius:var(--radius-md);
  background:var(--surface);border:1px solid var(--hairline);
  font-size:14px;color:rgba(255,255,255,.78);
}
.how-note b{color:#fff;}

/* ==========================================================================
   Recap chapter
   ========================================================================== */
.more-grid{display:grid;gap:14px;grid-template-columns:1fr;margin:18px 0;}
@media (min-width:640px){.more-grid{grid-template-columns:repeat(3,1fr);}}
.more-card{
  padding:18px;background:var(--surface);border:1px solid var(--hairline);
  border-radius:var(--radius-md);transition:transform .2s var(--ease),border-color .2s var(--ease);
}
.more-card:hover{transform:translateY(-3px);border-color:rgba(39,119,243,.5);}
.more-card h4{font-size:15.5px;margin-bottom:.3em;color:#fff;}
.more-card p{font-size:13.5px;color:rgba(255,255,255,.72);margin:0;}
.more-card .tagline{font-size:11px;text-transform:uppercase;letter-spacing:.08em;color:var(--blue-2);font-weight:600;display:block;margin-bottom:8px;}

.recap-cta{
  margin-top:26px;padding:28px;text-align:center;
  background:radial-gradient(120% 120% at 50% 0%,rgba(39,119,243,.14),rgba(39,119,243,0) 70%),var(--surface);
  border:1px solid var(--hairline);border-radius:var(--radius-lg);
}
.recap-cta h3{font-size:1.4rem;margin-bottom:.35em;}
.recap-cta p{max-width:46ch;margin:0 auto 18px;color:rgba(255,255,255,.8);}
.recap-cta .cta-row{display:flex;flex-wrap:wrap;gap:12px;justify-content:center;}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer{border-top:1px solid var(--hairline);padding:40px 0 32px;margin-top:20px;}
.footer-inner{display:flex;flex-wrap:wrap;gap:20px;align-items:center;justify-content:space-between;}
.footer-brand{display:flex;align-items:center;gap:14px;}
.footer-brand .logo{height:22px;width:auto;}
.footer-brand p{margin:0;font-size:13px;color:var(--gray);max-width:32ch;}
.footer-legal{font-size:12.5px;color:var(--gray);}
.footer-legal .attr{color:rgba(255,255,255,.7);font-weight:600;}

/* ==========================================================================
   Scroll reveal
   ========================================================================== */
.reveal{opacity:0;transform:translateY(14px);transition:opacity .6s var(--ease),transform .6s var(--ease);}
.reveal.is-visible{opacity:1;transform:none;}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width:960px){
  :root{--header-h:64px;}
  .brand-lockup .logo{height:34px;}
  .tutorial-layout{grid-template-columns:1fr;gap:0;padding-top:20px;}
  .brand-tag{display:none;}
  .rail-toggle{display:inline-flex;}

  /* Rail becomes a dropdown panel under the header */
  .chapter-rail{
    position:fixed;left:0;right:0;top:calc(var(--header-h) + var(--progress-h));
    z-index:190;max-height:calc(100vh - var(--header-h) - var(--progress-h));
    overflow-y:auto;
    background:rgba(6,6,6,.98);backdrop-filter:blur(10px);
    border-bottom:1px solid var(--hairline);
    padding:18px 24px 24px;
    transform:translateY(-8px);opacity:0;visibility:hidden;
    transition:opacity .2s var(--ease),transform .2s var(--ease),visibility .2s;
  }
  .chapter-rail.is-open{transform:none;opacity:1;visibility:visible;}
}
@media (min-width:961px){
  .chapter-rail{opacity:1 !important;visibility:visible !important;}
}
@media (max-width:600px){
  .container{padding:0 18px;}
  .chapter-nav{flex-wrap:wrap;gap:10px;}
  .chapter-nav .spacer{display:none;}
  .chapter-nav .btn{flex:1;min-width:0;}
  .hero-cta .btn{flex:1;justify-content:center;}
  .phone-shot img{max-height:none;max-width:min(100%,360px);}
  .app-nav .tab{font-size:11px;padding:10px 4px;}
}

@media (prefers-reduced-motion:reduce){
  *{animation-duration:.01ms !important;transition-duration:.01ms !important;}
  html{scroll-behavior:auto;}
  .reveal{opacity:1;transform:none;}
}