/* APS Tinkering Lab Robokriti 2026 — production polish layer
   Visual/UX improvements only. Existing text/content is untouched. */
:root{--st-ease:cubic-bezier(.16,1,.3,1);--st-glow:rgba(0,194,255,.22);--st-gold:rgba(212,175,55,.18)}
html{scroll-padding-top:88px}
body{-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
::selection{background:rgba(0,194,255,.28);color:#fff}

/* Premium navigation */
.site-header{isolation:isolate;transition:background .45s var(--st-ease),border-color .45s var(--st-ease),box-shadow .45s var(--st-ease),transform .45s var(--st-ease)}
.site-header.scrolled{backdrop-filter:blur(18px) saturate(140%);-webkit-backdrop-filter:blur(18px) saturate(140%);box-shadow:0 12px 40px rgba(0,0,0,.22)}
.site-header::after{content:"";position:absolute;left:0;right:0;bottom:-1px;height:1px;background:linear-gradient(90deg,transparent,rgba(0,194,255,.55),rgba(212,175,55,.35),transparent);opacity:.45;pointer-events:none}
nav a{position:relative}
nav a::after{content:"";position:absolute;left:50%;bottom:-7px;width:0;height:2px;transform:translateX(-50%);background:linear-gradient(90deg,#00c2ff,#d4af37);box-shadow:0 0 10px rgba(0,194,255,.6);transition:width .35s var(--st-ease)}
nav a:hover::after,nav a.active::after{width:70%}

/* Buttons */
.btn{position:relative;overflow:hidden;isolation:isolate;transform:translateZ(0);box-shadow:0 8px 28px rgba(0,0,0,.16)}
.btn::before{content:"";position:absolute;inset:0;transform:translateX(-115%);background:linear-gradient(100deg,transparent,rgba(255,255,255,.18),transparent);transition:transform .7s var(--st-ease);z-index:-1}
.btn:hover::before{transform:translateX(115%)}
.btn:hover{transform:translateY(-2px);box-shadow:0 14px 38px rgba(0,194,255,.12)}
.btn:active{transform:translateY(0) scale(.985)}

/* Section atmosphere */
.section{position:relative;isolation:isolate}
.section::before{content:"";position:absolute;inset:0;pointer-events:none;z-index:-1;background:radial-gradient(circle at 8% 12%,rgba(0,194,255,.035),transparent 28%),radial-gradient(circle at 92% 80%,rgba(212,175,55,.025),transparent 25%)}
.section-head h2{letter-spacing:-.025em}

/* Arena / command / operation cards */
.arena-card,.core-card,.leadership-feature,.operations-grid article,.contact-card{position:relative;overflow:hidden;transform:translateZ(0)}
.arena-card::before,.core-card::before,.leadership-feature::before,.operations-grid article::before,.contact-card::before{content:"";position:absolute;inset:0;background:linear-gradient(125deg,rgba(0,194,255,.07),transparent 34%,transparent 66%,rgba(212,175,55,.045));opacity:0;transition:opacity .5s var(--st-ease);pointer-events:none}
.arena-card::after,.core-card::after,.leadership-feature::after,.operations-grid article::after,.contact-card::after{content:"";position:absolute;top:0;left:0;width:42%;height:1px;background:linear-gradient(90deg,rgba(0,194,255,.75),transparent);transform:scaleX(0);transform-origin:left;transition:transform .55s var(--st-ease);pointer-events:none}
.arena-card:hover,.core-card:hover,.leadership-feature:hover,.operations-grid article:hover,.contact-card:hover{transform:translateY(-6px)}
.arena-card:hover::before,.core-card:hover::before,.leadership-feature:hover::before,.operations-grid article:hover::before,.contact-card:hover::before{opacity:1}
.arena-card:hover::after,.core-card:hover::after,.leadership-feature:hover::after,.operations-grid article:hover::after,.contact-card:hover::after{transform:scaleX(1)}

/* Hero depth */
.tech-hero{isolation:isolate;overflow:hidden}
.tech-hero::after{content:"";position:absolute;inset:0;pointer-events:none;background:linear-gradient(90deg,rgba(0,0,0,.1),transparent 35%,transparent 65%,rgba(0,0,0,.16));z-index:0}
.hero-content,.hero-visual{position:relative;z-index:2}
.hero-content h1{text-shadow:0 0 38px rgba(0,194,255,.08)}
.hero-meta span{transition:color .35s ease,transform .35s var(--st-ease)}
.hero-meta span:hover{color:#fff;transform:translateY(-2px)}

/* Loading */
.preloader{backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px)}
.loader-core{filter:drop-shadow(0 0 14px rgba(0,194,255,.35))}

/* Focus accessibility */
:focus-visible{outline:2px solid #00c2ff;outline-offset:4px}

/* Mobile polish */
@media(max-width:800px){
  html{scroll-padding-top:72px}
  .site-header{backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px)}
  nav a::after{display:none}
  .btn:hover{transform:none}
  .arena-card:hover,.core-card:hover,.leadership-feature:hover,.operations-grid article:hover,.contact-card:hover{transform:none}
}

@media(prefers-reduced-motion:reduce){
  .btn::before,nav a::after,.arena-card::before,.core-card::before,.leadership-feature::before,.operations-grid article::before,.contact-card::before,.arena-card::after,.core-card::after,.leadership-feature::after,.operations-grid article::after,.contact-card::after{transition:none!important}
}