/* Keystone case study funnel — 2026 brand guide. Gold #BB904A (accent, restrained) · Charcoal #2D3236 · Off White #F7F5EF. Anton + Montserrat. */
:root{
  --gold:#BB904A; --gold-12:rgba(187,144,74,.12); --gold-30:rgba(187,144,74,.3); --gold-55:rgba(187,144,74,.55);
  --char:#2D3236; --char-deep:#23272A; --char-card:#353B40;
  --off:#F7F5EF; --off-80:rgba(247,245,239,.8); --off-60:rgba(247,245,239,.62); --off-10:rgba(247,245,239,.1); --off-06:rgba(247,245,239,.06);
  --head:Anton,Impact,"Arial Narrow Bold",sans-serif; --body:Montserrat,-apple-system,BlinkMacSystemFont,"Segoe UI",Arial,sans-serif;
  --r:14px;
}
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body.cs{margin:0;background:var(--char);color:var(--off);font:400 16px/1.6 var(--body);-webkit-font-smoothing:antialiased;overflow-x:hidden}
.cs a{color:inherit}
.cs h1,.cs h2,.cs h3{margin:0;font-weight:400}
.cs p{margin:0}
.cs-wrap{max-width:1040px;margin:0 auto;padding:0 16px}
.cs-narrow{max-width:760px}
.cs-draft{background:var(--gold);color:var(--char);text-align:center;font:700 .75rem/1.3 var(--body);letter-spacing:.08em;text-transform:uppercase;padding:8px 12px}

/* Top */
.cs-top{display:flex;justify-content:center;padding:16px;border-bottom:1px solid var(--off-06)}
.cs-brand{display:inline-flex;line-height:0}
.cs-logo{width:170px;height:auto;display:block}
@media (min-width:760px){.cs-logo{width:200px}}

/* Hero */
.cs-hero{padding:28px 0 12px;text-align:center;background:radial-gradient(120% 70% at 50% 0%,var(--char-card) 0%,var(--char) 60%)}
.cs-eyebrow{display:inline-block;font:600 .72rem/1 var(--body);letter-spacing:.2em;text-transform:uppercase;color:var(--gold);border:1px solid var(--gold-30);border-radius:999px;padding:8px 14px}
.cs-h1{margin-top:16px!important;font-family:var(--head);text-transform:uppercase;font-size:clamp(2.1rem,9.4vw,3.6rem);line-height:1.04;letter-spacing:.01em}
.cs-h1 em{font-style:normal;color:var(--gold)}
.cs-sub{margin:14px auto 0!important;max-width:640px;font-size:clamp(1rem,4.2vw,1.2rem);color:var(--off-80);line-height:1.5}
.cs-sub strong{color:var(--off);font-weight:600}
.cs-col{max-width:760px;margin:22px auto 0;text-align:left}
.cs-col--wide{max-width:960px}
.cs-watch{background:var(--gold);color:var(--char);text-align:center;font:700 .75rem/1 var(--body);letter-spacing:.18em;text-transform:uppercase;padding:10px 12px;border-radius:var(--r) var(--r) 0 0}
.cs-watch + .cs-video{border-radius:0 0 var(--r) var(--r);border-top:0}

/* Video */
.cs-video{position:relative;aspect-ratio:16/9;background:#000 center/cover no-repeat;border:1px solid var(--gold-30);border-radius:var(--r);overflow:hidden;cursor:pointer;box-shadow:0 30px 60px -30px rgba(0,0,0,.9)}
.cs-video iframe,.cs-video video,.cs-video>div[id^="yt-"]{position:absolute;inset:0;width:100%;height:100%;border:0;display:block;background:#000}
.cs-play{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);width:76px;height:76px;border-radius:50%;background:var(--gold);color:var(--char);display:grid;place-items:center;box-shadow:0 0 0 10px var(--gold-12);transition:transform .15s}
.cs-play svg{margin-left:4px}
.cs-video:hover .cs-play{transform:translate(-50%,-50%) scale(1.05)}
.cs-video.is-playing .cs-play{display:none}
.cs-progress{position:absolute;left:0;right:0;bottom:0;height:4px;background:var(--off-10);z-index:3;pointer-events:none}
.cs-progress i{display:block;height:100%;width:0;background:var(--gold);transition:width .3s linear}
.cs-video--empty{cursor:default;background:var(--char-deep);border-style:dashed}
.cs-video-ph{position:absolute;inset:0;display:grid;place-content:center;gap:6px;text-align:center;padding:16px;color:var(--off-60);font-size:.875rem}
.cs-video-ph b{font-family:var(--head);font-weight:400;text-transform:uppercase;letter-spacing:.06em;color:var(--off);font-size:1.25rem}
.cs-under{display:flex;flex-wrap:wrap;justify-content:center;gap:6px 16px;margin-top:12px;font-size:.875rem;color:var(--off-60)}
.cs-under span::before{content:"✓";color:var(--gold);font-weight:700;margin-right:6px}

/* Form card */
.cs-card{max-width:560px;margin:20px auto 0;background:var(--off);color:var(--char);border-radius:20px;padding:22px 18px;text-align:left;box-shadow:0 30px 60px -30px rgba(0,0,0,.9);border-top:4px solid var(--gold);scroll-margin-top:12px}
.cs-card h2{font-family:var(--head);text-transform:uppercase;font-size:1.6rem;line-height:1.1;text-align:center;color:var(--char)}
.cs-lead{margin-top:6px!important;text-align:center;font-size:.9375rem;color:rgba(45,50,54,.75)}
.cs-form{display:grid;gap:12px}
.cs-form[hidden]{display:none}
.cs-row2{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.cs-form label{display:block;font-size:.8125rem;font-weight:600;margin-bottom:5px;color:var(--char)}
.cs-form input:not([type=checkbox]),.cs-form select{width:100%;min-height:52px;padding:12px 14px;font:inherit;font-size:1rem;border:1.5px solid rgba(45,50,54,.25);border-radius:12px;background:#fff;color:var(--char);appearance:none;-webkit-appearance:none}
.cs-form select{background-image:linear-gradient(45deg,transparent 50%,var(--char) 50%),linear-gradient(135deg,var(--char) 50%,transparent 50%);background-position:calc(100% - 20px) 50%,calc(100% - 14px) 50%;background-size:6px 6px;background-repeat:no-repeat;padding-right:36px}
.cs-form input:focus,.cs-form select:focus{outline:none;border-color:var(--gold);box-shadow:0 0 0 4px var(--gold-30)}
.cs-form .is-bad{border-color:var(--gold)!important;box-shadow:0 0 0 3px var(--gold-30)}
.cs-check{display:flex!important;gap:10px;align-items:flex-start;font-weight:400!important;font-size:.8125rem!important;line-height:1.45;color:rgba(45,50,54,.8)!important;cursor:pointer}
.cs-check input{width:22px;height:22px;flex:0 0 22px;margin:0;accent-color:var(--gold)}
.cs-check.is-bad span{text-decoration:underline;text-decoration-color:var(--gold);text-decoration-thickness:2px}
.cs-err{font-size:.875rem;font-weight:600;color:var(--char);background:var(--gold-12);border-left:3px solid var(--gold);padding:8px 10px;border-radius:6px}
.cs-safe{text-align:center;font-size:.8125rem;color:rgba(45,50,54,.6)}
.cs-hp{position:absolute!important;left:-9999px!important;width:1px;height:1px;overflow:hidden}

/* Buttons */
.cs-btn{display:inline-flex;align-items:center;justify-content:center;width:100%;min-height:58px;padding:0 24px;border:0;border-radius:12px;background:var(--gold);color:var(--char);font:400 1.2rem/1 var(--head);letter-spacing:.06em;text-transform:uppercase;text-decoration:none;cursor:pointer;-webkit-tap-highlight-color:transparent;transition:filter .2s,transform .1s}
.cs-btn:hover{filter:brightness(1.06)}.cs-btn:active{transform:translateY(1px)}
.cs-btn[disabled]{opacity:.65;cursor:progress}
.cs-btn--inline{max-width:420px}

/* Sections */
.cs-section{padding:40px 0 8px}
.cs-h2{font-family:var(--head);text-transform:uppercase;text-align:center;font-size:clamp(1.6rem,6.4vw,2.2rem);line-height:1.1}
.cs-h3{font-family:var(--head);text-transform:uppercase;font-size:clamp(1.35rem,5.4vw,1.7rem);line-height:1.1}
.cs-intro{text-align:center;color:var(--off-80);margin:10px auto 0!important;max-width:580px}
.cs-fine{margin-top:12px!important;text-align:center;font-size:.8125rem;color:var(--off-60);line-height:1.5}
.cs-fine a{color:var(--off-80)}
.cs-reveals{display:grid;gap:10px;margin-top:20px}
.cs-reveal{display:grid;grid-template-columns:40px 1fr;gap:14px;background:var(--char-deep);border:1px solid var(--off-06);border-radius:var(--r);padding:16px}
.cs-num{width:40px;height:40px;border-radius:10px;background:var(--gold-12);color:var(--gold);font:400 1.25rem/1 var(--head);display:grid;place-items:center}
.cs-reveal h3{font:700 1.0625rem/1.3 var(--body)}
.cs-reveal p{margin-top:4px!important;color:var(--off-80);font-size:.9375rem}
.cs-panel{background:var(--char-deep);border:1px solid var(--off-06);border-radius:18px;padding:22px 18px}
.cs-panel p{margin-top:10px!important;color:var(--off-80)}
.cs-panel[hidden]{display:none}
.cs-ticks{list-style:none;margin:14px 0 0;padding:0;display:grid;gap:10px}
.cs-ticks li{position:relative;padding-left:26px;color:var(--off-80);font-size:.9375rem}
.cs-ticks li::before{content:"";position:absolute;left:0;top:.45em;width:12px;height:12px;background:var(--gold);clip-path:polygon(0 70%,25% 70%,25% 45%,50% 45%,50% 20%,75% 20%,75% 0,100% 0,100% 100%,0 100%)}
.cs-panel .cs-fine{text-align:left}

/* Stats */
.cs-stats{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin-top:20px}
.cs-stat{background:var(--char-deep);border:1px solid var(--gold-30);border-radius:var(--r);padding:16px 8px;text-align:center}
.cs-stat b{display:block;font:400 clamp(1.5rem,7vw,2.4rem)/1 var(--head);color:var(--off)}
.cs-stat:nth-child(2) b{color:var(--gold)}
.cs-stat span{display:block;margin-top:6px;font-size:.75rem;line-height:1.35;color:var(--off-60)}
.cs-quote{margin:20px 0 0;padding:18px;border-left:3px solid var(--gold);background:var(--char-deep);border-radius:0 var(--r) var(--r) 0}
.cs-quote p{font-size:1.0625rem;font-style:italic}
.cs-quote cite{display:block;margin-top:8px;font-style:normal;font-size:.875rem;color:var(--gold)}

/* Booking */
.cs-book{background:var(--off);color:var(--char);border-radius:20px;padding:24px 14px 16px;border-top:4px solid var(--gold)}
.cs-book .cs-h2{color:var(--char)}
.cs-book .cs-intro{color:rgba(45,50,54,.8)}
.cs-book .cs-fine,.cs-book .cs-fine a{color:rgba(45,50,54,.65)}
.cs-book[hidden]{display:none}
.cs-cal{margin-top:16px;min-height:640px;background:#fff;border-radius:12px;overflow:hidden}
.cs-cal iframe{width:100%;min-height:640px;border:0;display:block}

/* Founder */
.cs-founder{display:grid;gap:16px;background:linear-gradient(180deg,var(--char-card),var(--char-deep));border:1px solid var(--gold-30);border-radius:20px;padding:22px 18px}
.cs-face{width:88px;height:88px;border-radius:50%;overflow:hidden;border:2px solid var(--gold-55);background:var(--char-deep);display:grid;place-items:center;font-size:.75rem;color:var(--off-60)}
.cs-face img{width:100%;height:100%;object-fit:cover}
.cs-who{margin-top:4px!important;color:var(--gold);font-weight:600;font-size:.875rem}
.cs-body{margin-top:10px!important;color:var(--off-80);font-size:.9375rem}
.cs-facts{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:14px}
.cs-fact{background:rgba(0,0,0,.18);border:1px solid var(--off-10);border-radius:12px;padding:12px 8px;text-align:center}
.cs-fact b{display:block;font:400 1.4rem/1 var(--head)}
.cs-fact span{display:block;margin-top:5px;font-size:.75rem;color:var(--off-60)}

/* FAQ */
.cs-faq{display:grid;gap:8px;margin-top:20px}
.cs-faq details{background:var(--char-deep);border:1px solid var(--off-06);border-radius:12px;padding:0 16px}
.cs-faq summary{list-style:none;cursor:pointer;padding:16px 0;font-weight:600;display:flex;justify-content:space-between;gap:12px}
.cs-faq summary::-webkit-details-marker{display:none}
.cs-faq summary::after{content:"+";color:var(--gold);font-size:1.4rem;line-height:1}
.cs-faq details[open] summary::after{content:"–"}
.cs-faq details p{padding:0 0 16px;color:var(--off-80);font-size:.9375rem}

/* Bottom, footer, sticky */
.cs-bottom{text-align:center;padding:32px 0 40px}
.cs-foot{border-top:1px solid var(--off-06);padding:24px 16px 96px;text-align:center;font-size:.75rem;color:var(--off-60);display:grid;gap:6px}
.cs-sticky{position:fixed;left:0;right:0;bottom:0;z-index:40;padding:10px 16px calc(10px + env(safe-area-inset-bottom));background:linear-gradient(180deg,rgba(45,50,54,0),var(--char) 35%)}
.cs-sticky[hidden]{display:none}

@media (min-width:760px){
  .cs-hero{padding-top:44px}
  .cs-card{padding:28px 30px}
  .cs-founder{grid-template-columns:96px 1fr;padding:28px}
  .cs-face{width:96px;height:96px}
  .cs-facts{grid-template-columns:repeat(2,minmax(0,180px))}
  .cs-sticky{display:none!important}
  .cs-foot{padding-bottom:32px}
  .cs-book{padding:32px 28px 20px}
}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}

/* Tap for sound (muted autoplay, 9 Oct) */
.cs-sound{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);z-index:5;display:flex;align-items:center;gap:8px;padding:14px 22px;border:0;border-radius:999px;background:var(--gold,#BB904A);color:var(--char,#2D3236);font:700 1rem/1 var(--body,Montserrat,sans-serif);box-shadow:0 0 0 10px rgba(187,144,74,.25),0 12px 30px rgba(0,0,0,.45);cursor:pointer;animation:cs-pulse 1.6s ease-in-out infinite}
@keyframes cs-pulse{50%{box-shadow:0 0 0 18px rgba(187,144,74,.08),0 12px 30px rgba(0,0,0,.45)}}
@media (prefers-reduced-motion:reduce){.cs-sound{animation:none}}