/* ========================================================================
   SAIL — Sociotechnical AI Lab
   Light, clean palette · solid backgrounds (no gradients)
   Bright Blue #2563EB · Red #E23B3B · Navy text #15336b
   ===================================================================== */
:root{
  --navy:#15336b;
  --blue:#2563EB;
  --blue-600:#1d4fd0;
  --blue-light:#60a5fa;
  --red:#e23b3b;
  --ink:#23304d;
  --muted:#5e6a80;
  --line:#e3e9f3;
  --bg:#ffffff;
  --bg-soft:#f4f7fc;
  --bg-blue:#e9f1fd;
  --bg-tint:#eaf1fe;
  --radius:18px;
  --shadow-sm:0 2px 12px rgba(21,51,107,.07);
  --shadow:0 14px 40px rgba(21,51,107,.10);
  --shadow-lg:0 26px 64px rgba(21,51,107,.16);
  --maxw:1180px;
  --ease:cubic-bezier(.16,.84,.36,1);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;font-family:"Inter",system-ui,sans-serif;color:var(--ink);
  background:var(--bg);line-height:1.65;-webkit-font-smoothing:antialiased;font-size:17px;
}
h1,h2,h3,h4,h5{font-family:"Sora",sans-serif;color:var(--navy);line-height:1.16;margin:0}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
section{padding:clamp(64px,8vw,116px) 24px}

.trustword{font-family:"Sora",sans-serif;font-weight:800;letter-spacing:.05em;color:var(--blue)}
.trustword b{color:var(--red)}

/* ====================== NAV ====================== */
.nav{
  position:fixed;top:0;left:0;right:0;z-index:50;padding:14px 0;
  background:#fff;box-shadow:var(--shadow-sm);
  transition:box-shadow .3s var(--ease),padding .3s var(--ease);
}
.nav.scrolled{padding:9px 0;box-shadow:0 4px 18px rgba(21,51,107,.10)}
.nav__inner{max-width:var(--maxw);margin:0 auto;padding:0 24px;display:flex;align-items:center;justify-content:space-between;gap:24px}

.brand{display:flex;align-items:center;gap:11px}
.brand__mark{display:grid;place-items:center}
.brand__mark img{border-radius:8px;display:block}
.brand__text{display:flex;flex-direction:column;line-height:1.05}
.brand__text strong{font-family:"Sora";font-weight:800;font-size:1.22rem;letter-spacing:.14em;color:var(--navy)}
.brand__text em{font-style:normal;font-size:.72rem;color:var(--muted);letter-spacing:.04em}

.nav__links{display:flex;gap:4px;align-items:center}
.nav__links a{
  font-weight:600;font-size:1rem;color:var(--navy);padding:9px 16px;border-radius:999px;
  transition:background .2s,color .2s;
}
.nav__links a:hover{background:var(--bg-tint)}
.nav__links a.is-active{color:var(--blue);background:var(--bg-tint)}

.nav__toggle{display:none;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer;padding:8px;z-index:60}
.nav__toggle span{width:24px;height:2px;background:var(--navy);border-radius:2px;transition:.3s}

/* ====================== HERO ====================== */
.hero{
  position:relative;min-height:100vh;display:flex;align-items:center;justify-content:center;
  text-align:center;overflow:hidden;padding:130px 24px 96px;
  background:var(--bg-blue);color:var(--ink);
}
.hero__canvas{position:absolute;inset:0;width:100%;height:100%;z-index:1}
.hero__wordcloud{position:absolute;inset:0;z-index:2;pointer-events:none;overflow:hidden}
.hero__overlay{display:none}
.hero__content{position:relative;z-index:4;max-width:900px}

.hero__eyebrow{
  text-transform:uppercase;letter-spacing:.2em;font-size:.82rem;font-weight:700;
  color:var(--blue);margin:0 0 18px;
}
.hero__title{
  font-size:clamp(3rem,8vw,5.6rem);font-weight:800;letter-spacing:-.02em;color:var(--navy);margin:0 0 24px;
}
.hero__title .grad{color:var(--blue)}
.hero__abbr{color:var(--blue);font-weight:800}
.hero__title.is-typing{min-height:1.16em}
.type-caret{
  display:inline-block;width:3px;height:.92em;margin-left:5px;border-radius:2px;
  background:var(--blue);vertical-align:-2px;animation:caretBlink 1s steps(1) infinite;
}
@keyframes caretBlink{0%,49%{opacity:1}50%,100%{opacity:0}}
.hero__lede{
  font-size:clamp(1.12rem,2vw,1.34rem);color:#3c4866;max-width:680px;margin:0 auto 32px;
}

.hero__trust{display:flex;flex-wrap:wrap;justify-content:center;gap:11px;margin:0 auto 18px;max-width:760px}
.hero__trust span{
  font-size:1rem;font-weight:500;color:#3c4866;padding:9px 18px;border-radius:999px;
  background:#fff;border:1px solid var(--line);box-shadow:var(--shadow-sm);
  transition:transform .25s var(--ease),border-color .25s;
}
.hero__trust span:hover{transform:translateY(-3px);border-color:var(--blue)}
.hero__trust b{color:var(--blue);font-weight:800;font-size:1.18rem}

.hero__tagline{font-size:1.32rem;font-weight:600;color:var(--navy);margin:8px 0 34px}
.hero__tagline .trustword{font-size:1.5rem}

.hero__cta{display:flex;gap:14px;justify-content:center;flex-wrap:wrap}

.hero__scroll{
  position:absolute;bottom:26px;left:50%;transform:translateX(-50%);z-index:4;
  width:26px;height:42px;border:2px solid rgba(37,99,235,.5);border-radius:14px;
}
.hero__scroll span{
  position:absolute;top:8px;left:50%;width:4px;height:8px;border-radius:2px;background:var(--blue);
  transform:translateX(-50%);animation:scrolldot 1.7s infinite;
}
@keyframes scrolldot{0%{opacity:0;top:8px}40%{opacity:1}80%{opacity:0;top:22px}100%{opacity:0}}

/* floating words */
.floatword{
  position:absolute;font-family:"Sora";font-weight:700;white-space:nowrap;
  color:rgba(37,99,235,.07);user-select:none;letter-spacing:.02em;animation:floaty linear infinite;
}
.floatword b{color:rgba(226,59,59,.18);font-weight:800}
@keyframes floaty{
  0%{transform:translateY(20px);opacity:0}15%{opacity:1}85%{opacity:1}100%{transform:translateY(-60px);opacity:0}
}

/* ====================== BUTTONS ====================== */
.btn{
  display:inline-flex;align-items:center;gap:8px;font-weight:600;font-size:1.02rem;
  padding:14px 28px;border-radius:999px;cursor:pointer;border:1.5px solid transparent;
  transition:transform .25s var(--ease),box-shadow .25s,background .25s,color .25s;
}
.btn--primary{background:var(--blue);color:#fff;box-shadow:0 10px 24px rgba(37,99,235,.32)}
.btn--primary:hover{background:var(--blue-600);transform:translateY(-3px);box-shadow:0 16px 34px rgba(37,99,235,.4)}
.btn--ghost{background:#fff;color:var(--blue);border-color:var(--blue)}
.btn--ghost:hover{background:var(--bg-tint);transform:translateY(-3px)}

/* ====================== SECTION HEADERS ====================== */
.section-head{max-width:780px;margin:0 auto clamp(40px,5vw,64px);text-align:center}
.kicker{text-transform:uppercase;letter-spacing:.18em;font-size:.82rem;font-weight:700;color:var(--blue);margin:0 0 14px}
.section-head h2{font-size:clamp(1.9rem,4vw,2.7rem);font-weight:800;letter-spacing:-.01em}
.section-sub{color:var(--muted);font-size:1.15rem;margin:16px auto 0;max-width:660px}

/* ====================== OVERVIEW / DIAGRAM ====================== */
.overview{background:var(--bg)}
.diagram{
  max-width:960px;margin:0 auto;
  display:grid;grid-template-columns:1fr 1fr;gap:22px;
}

.node{
  position:relative;background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:22px;box-shadow:var(--shadow-sm);overflow:hidden;
  display:flex;flex-direction:row;align-items:center;gap:20px;
  transition:transform .3s var(--ease),box-shadow .3s var(--ease),border-color .3s;
}
.node::before{content:"";position:absolute;top:0;left:0;width:100%;height:4px;
  background:var(--blue);transform:scaleX(0);transform-origin:left;transition:transform .4s var(--ease)}
.node--app::before{background:var(--red)}
.node:hover{transform:translateY(-6px);box-shadow:var(--shadow-lg);border-color:transparent}
.node:hover::before{transform:scaleX(1)}

.node__img{
  width:196px;height:196px;flex-shrink:0;object-fit:contain;border-radius:14px;
  background:var(--bg-soft);padding:10px;transition:transform .35s var(--ease);
}
.node:hover .node__img{transform:scale(1.04)}

.node__body{display:flex;flex-direction:column;align-items:flex-start;gap:8px;flex:1}
.node__tag{
  font-size:.72rem;font-weight:700;text-transform:uppercase;letter-spacing:.12em;
  padding:5px 12px;border-radius:999px;background:var(--bg-tint);color:var(--blue);
}
.node--app .node__tag{background:#fdeaea;color:var(--red)}
.node h3{font-size:1.3rem;font-weight:700}
.node p{color:var(--muted);font-size:1rem;margin:0}
.node__more{font-weight:700;font-size:.98rem;color:var(--blue);transition:transform .2s}
.node--app .node__more{color:var(--red)}
.node:hover .node__more{transform:translateX(5px)}

.overview__desc{max-width:840px;margin:clamp(46px,5vw,66px) auto 0;display:grid;gap:18px}
.overview__desc p{color:#374257;font-size:1.12rem;margin:0}
.overview__desc a{color:var(--blue);font-weight:600;border-bottom:1px solid rgba(37,99,235,.3)}
.overview__desc strong{color:var(--navy)}

/* ====================== TRUST VALUES ====================== */
.trust{background:var(--bg-blue)}
.trust .section-head h2{color:var(--navy)}
.trust__grid{max-width:var(--maxw);margin:0 auto;display:grid;gap:20px;grid-template-columns:repeat(5,1fr)}
.value{
  background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px 20px;
  position:relative;overflow:hidden;box-shadow:var(--shadow-sm);
  transition:transform .3s var(--ease),box-shadow .3s,border-color .3s;
}
.value:hover{transform:translateY(-6px);box-shadow:var(--shadow);border-color:var(--blue-light)}
.value__letter{position:absolute;top:-10px;right:8px;font-family:"Sora";font-weight:800;font-size:5rem;color:rgba(37,99,235,.07);line-height:1}
.value__ic{width:48px;height:48px;border-radius:13px;display:grid;place-items:center;background:var(--bg-tint);color:var(--blue);margin-bottom:14px}
.value__ic svg{width:25px;height:25px}
.value h4{color:var(--navy);font-size:1.18rem;margin-bottom:8px}
.value p{color:var(--muted);font-size:.96rem;margin:0}

/* ====================== JOIN CTA ====================== */
.join{background:var(--bg)}
.join__inner{
  max-width:900px;margin:0 auto;text-align:center;border-radius:28px;padding:clamp(44px,6vw,76px) 32px;
  background:var(--bg-blue);border:1px solid #d3e3fb;color:var(--ink);box-shadow:var(--shadow);
}
.join__inner h2{color:var(--navy);font-size:clamp(1.7rem,3.5vw,2.4rem)}
.join__inner p{color:var(--muted);max-width:580px;margin:16px auto 30px;font-size:1.12rem}

/* ====================== FOOTER ====================== */
.footer{background:var(--bg-soft);border-top:1px solid var(--line)}
.footer__inner{
  max-width:var(--maxw);margin:0 auto;padding:62px 24px 40px;
  display:grid;grid-template-columns:1.6fr 1fr 1.2fr 1.4fr;gap:40px;
}
.brand--footer .brand__text strong{color:var(--navy)}
.brand--footer .brand__text em{color:var(--muted)}
.footer__about{margin-top:16px;font-size:.98rem;max-width:270px;color:var(--muted)}
.footer__col h5{color:var(--navy);font-family:"Sora";font-size:1rem;margin-bottom:16px;letter-spacing:.03em}
.footer__col a{display:block;color:var(--muted);font-size:.98rem;padding:5px 0;transition:color .2s}
.footer__col a:hover{color:var(--blue)}
.footer__col p a{display:inline;padding:0}
.footer__col p{font-size:.98rem;margin:0 0 10px;color:var(--muted)}
.footer__col--logo{display:flex;align-items:flex-start;justify-content:flex-end}
.footer__col--logo img{max-width:240px}
.footer__bar{border-top:1px solid var(--line);text-align:center;padding:22px;font-size:.9rem;color:var(--muted)}

/* ====================== REVEAL ====================== */
.reveal{opacity:0;transform:translateY(28px);transition:opacity .7s var(--ease),transform .7s var(--ease)}
.reveal.in{opacity:1;transform:none}

/* ====================== RESPONSIVE ====================== */
@media(max-width:900px){
  .diagram{grid-template-columns:1fr}
  .footer__inner{grid-template-columns:1fr 1fr}
  .footer__col--logo{justify-content:flex-start}
  .trust__grid{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:760px){
  .nav__links{
    position:fixed;top:0;right:-100%;height:100vh;width:75%;max-width:320px;
    flex-direction:column;align-items:flex-start;gap:4px;padding:90px 28px;
    background:#fff;box-shadow:-20px 0 60px rgba(21,51,107,.18);transition:right .35s var(--ease);
  }
  .nav__links.open{right:0}
  .nav__links a{width:100%;padding:14px 16px;font-size:1.08rem}
  .nav__toggle{display:flex}
  .nav__toggle.open span:nth-child(1){transform:translateY(7px) rotate(45deg)}
  .nav__toggle.open span:nth-child(2){opacity:0}
  .nav__toggle.open span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

  .node{flex-direction:column;align-items:flex-start;text-align:left}
  .node__img{width:100%;height:200px}
  .trust__grid{grid-template-columns:1fr}
}
@media(max-width:480px){.footer__inner{grid-template-columns:1fr}}

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