/* Phone-first refinements for the interactive brief. */
@media(max-width:600px){
  .brief-page{overflow-x:hidden}
  .brief-page header{align-items:center;padding:12px 4%;gap:10px}
  .brief-page header .brand{gap:8px;min-width:0}
  .brief-page header .header-mark{width:42px;height:42px;flex:0 0 42px}
  .brief-page header .brand strong{font-size:13px;letter-spacing:1px}
  .brief-page header .brand small{display:none}
  .brief-page header nav{gap:6px;flex-shrink:0}
  .brief-page header nav a{min-height:44px;box-sizing:border-box;display:inline-flex!important;align-items:center;padding:9px 11px;font-size:13px}
  .brief-page main{padding:26px 16px max(44px,env(safe-area-inset-bottom))}
  .brief-top{gap:20px;margin-bottom:18px}
  .brief-top h1{font-size:clamp(34px,10vw,44px);line-height:1.04;letter-spacing:-1.5px}
  .view-control>span{font-size:13px;margin-bottom:7px}
  .view-control>div{width:100%;box-sizing:border-box}
  .view-control button{min-height:46px;padding:11px 10px}
  .brief-layout{gap:8px}
  .brief-layout aside{position:sticky;top:0;z-index:8;margin:0 -16px;background:linear-gradient(#f8f7f3 82%,rgba(248,247,243,0));padding:8px 16px 12px}
  .brief-layout aside nav{scrollbar-width:none;scroll-snap-type:x proximity;overscroll-behavior-x:contain;padding:0 0 5px}
  .brief-layout aside nav::-webkit-scrollbar{display:none}
  .brief-layout aside button{min-height:44px;scroll-snap-align:center;padding:10px 13px;border-radius:5px;font-size:14px;background:#efede7}
  .brief-layout aside button[aria-current=step]{background:#11283f;color:#fff;border-color:#a53348}
  .brief-layout aside button[aria-current=step] b{color:#dec58e}
  .progress-line{margin:4px 0 10px;font-size:10px;letter-spacing:1px}
  .progress-track{margin-bottom:14px}
  #chapter{border-radius:7px}
  .chapter-art{height:clamp(160px,48vw,210px);object-position:center}
  .chapter-content{padding:24px 18px 28px}
  .chapter-content .eyebrow{margin-bottom:10px;font-size:10px;letter-spacing:1.1px}
  .chapter-content h2{font-size:clamp(27px,8vw,34px);line-height:1.08;letter-spacing:-.8px;margin-bottom:15px;overflow-wrap:anywhere}
  .chapter-content>.intro{font-size:16px;line-height:1.55;overflow-wrap:anywhere}
  .view-note{margin:20px 0;padding:16px 17px}
  .brief-grid{gap:13px;margin-top:20px}
  .brief-card{padding:19px 17px}
  .brief-card h3{font-size:18px}
  .brief-card p,.brief-list p{font-size:15px;line-height:1.55}
  .brief-card summary{min-height:44px;display:flex;align-items:center;padding:12px 0 0}
  .brief-venture-icon{width:64px;height:64px}
  .brief-list{margin:20px 0}
  .brief-list li{gap:13px;padding:17px 0}
  .brief-list strong{font-size:17px}
  .flow{grid-template-columns:1fr;margin:20px 0;gap:10px}
  .flow div{padding:18px 16px}
  .contact-actions{display:grid;grid-template-columns:1fr;margin-top:22px}
  .contact-actions a{min-height:48px;box-sizing:border-box;display:flex;align-items:center;justify-content:center;text-align:center}
  .step-controls{position:sticky;bottom:0;z-index:9;display:grid;grid-template-columns:1fr auto 1fr;margin:16px -8px 0;padding:10px 8px calc(10px + env(safe-area-inset-bottom));background:rgba(248,247,243,.96);backdrop-filter:blur(10px);border-top:1px solid #dfdbd2}
  .step-controls button{min-height:48px;padding:10px 12px}
  .step-controls button:last-child{justify-self:stretch}
  .step-controls span{min-width:42px;text-align:center}
  .brief-page footer{padding-bottom:max(28px,env(safe-area-inset-bottom))}
}

@media(max-width:370px){
  .brief-page header .brand strong{font-size:11px;letter-spacing:.7px}
  .brief-page header nav a{padding:8px;font-size:12px}
  .brief-page main{padding-left:12px;padding-right:12px}
  .brief-layout aside{margin-left:-12px;margin-right:-12px;padding-left:12px;padding-right:12px}
  .step-controls{gap:6px}
  .step-controls button{font-size:13px;padding:9px 8px}
}