/* =========================================================
   SAHT Energy — stylesheet
   Design tokens grounded in the CFD suction/pressure imagery
   central to the technology: deep water blue, suction-vortex
   ink, and the red/orange high-pressure accent from the CFD
   plots. Background is a cool pale foam, not a warm cream.
   ========================================================= */

@import url('https://fonts.googleapis.com/css2?family=Fraunces:ital,opsz,wght@0,9..144,400;0,9..144,500;0,9..144,600;1,9..144,500&family=Inter:wght@400;500;600;700&family=IBM+Plex+Mono:wght@400;500&display=swap');

:root{
  --ink:        #0A2E38;
  --deep:       #123A5C;
  --teal:       #146C7A;
  --teal-dim:   #0F5560;
  --accent:     #D14B24;
  --accent-dim: #B03E1D;
  --bg:         #F2F6F6;
  --bg-alt:     #E3EEEE;
  --paper:      #FFFFFF;
  --line:       rgba(10,46,56,0.14);
  --line-soft:  rgba(10,46,56,0.08);
  --muted:      #4C6A72;

  --display: 'Fraunces', Georgia, serif;
  --body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --mono: 'IBM Plex Mono', 'SFMono-Regular', Consolas, monospace;

  --max: 1180px;
}

*, *::before, *::after{ box-sizing: border-box; }

html{ scroll-behavior: smooth; }

body{
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--body);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img{ max-width: 100%; display: block; }

a{ color: inherit; }

.wrap{
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 32px;
}

h1, h2, h3{
  font-family: var(--display);
  font-weight: 500;
  line-height: 1.08;
  margin: 0 0 .5em;
  letter-spacing: -0.01em;
}

h2{ font-size: clamp(1.7rem, 3vw, 2.4rem); }
h3{ font-size: 1.25rem; font-weight: 600; }

p{ margin: 0 0 1.1em; color: var(--ink); }

.eyebrow{
  font-family: var(--mono);
  font-size: .72rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--teal-dim);
  display: flex;
  align-items: center;
  gap: .6em;
  margin-bottom: 1em;
}
.eyebrow::before{
  content: "";
  width: 22px;
  height: 1px;
  background: var(--accent);
  display: inline-block;
}

/* ---------- skip link / focus ---------- */
.skip-link{
  position:absolute; left:-999px; top:auto;
  background:var(--ink); color:#fff; padding:10px 16px;
  z-index:200; border-radius:4px;
}
.skip-link:focus{ left:16px; top:16px; }

:focus-visible{
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

/* ---------- header ---------- */
.site-header{
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(242,246,246,0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line-soft);
}
.site-header .wrap{
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 84px;
}
.brand{
  display: flex;
  align-items: center;
  gap: .6em;
  text-decoration: none;
}
.brand img{ height: 50px; width: auto; } /* 25% larger than original 40px */

.nav-toggle{
  display: none;
  background: none;
  border: 1px solid var(--line);
  border-radius: 6px;
  width: 42px;
  height: 42px;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}
.nav-toggle span, .nav-toggle span::before, .nav-toggle span::after{
  display:block; width:18px; height:2px; background:var(--ink); position:relative; transition:.2s;
}
.nav-toggle span::before, .nav-toggle span::after{ content:""; position:absolute; }
.nav-toggle span::before{ top:-6px; }
.nav-toggle span::after{ top:6px; }

.main-nav ul{
  list-style: none;
  display: flex;
  gap: 2.1em;
  margin: 0;
  padding: 0;
}
.main-nav a{
  text-decoration: none;
  font-size: .93rem;
  font-weight: 500;
  color: var(--ink);
  padding: 6px 2px;
  border-bottom: 2px solid transparent;
  transition: border-color .15s, color .15s;
}
.main-nav a:hover{ color: var(--teal-dim); }
.main-nav a[aria-current="page"]{
  border-bottom-color: var(--accent);
  color: var(--teal-dim);
}

/* ---------- buttons ---------- */
.btn{
  display: inline-flex;
  align-items: center;
  gap: .5em;
  font-family: var(--body);
  font-weight: 600;
  font-size: .92rem;
  text-decoration: none;
  padding: .85em 1.5em;
  border-radius: 4px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform .15s ease, background .15s ease, color .15s ease, border-color .15s ease;
}
.btn:hover{ transform: translateY(-1px); }
.btn-primary{ background: var(--ink); color: #fff; }
.btn-primary:hover{ background: var(--accent); }
.btn-outline{ border-color: var(--line); color: var(--ink); background: transparent; }
.btn-outline:hover{ border-color: var(--accent); color: var(--accent-dim); }

/* ---------- hero (home) ---------- */
.hero{
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--line-soft);
}
.hero .wrap{
  display: grid;
  grid-template-columns: 1.05fr .95fr;
  gap: 3rem;
  align-items: center;
  padding-top: 4.5rem;
  padding-bottom: 3.5rem;
}
.hero h1{
  font-size: clamp(2.3rem, 4.4vw, 3.6rem);
}
.hero h1 em{
  font-style: italic;
  color: var(--teal-dim);
}
.hero .lede{
  font-size: 1.12rem;
  color: var(--muted);
  max-width: 46ch;
}
.hero-actions{
  display: flex;
  gap: 1em;
  margin-top: 1.6em;
  flex-wrap: wrap;
}

/* signature vortex graphic */
.vortex-stage{
  position: relative;
  aspect-ratio: 1 / 1;
  display: flex;
  align-items: center;
  justify-content: center;
}
.vortex-ring{
  position: absolute;
  border-radius: 50%;
  border: 1px solid var(--line);
  animation: spin linear infinite;
}
.vortex-ring.r1{ width: 100%; height: 100%; border-color: rgba(20,108,122,.35); animation-duration: 70s; }
.vortex-ring.r2{ width: 78%; height: 78%; border-color: rgba(209,75,36,.3); animation-duration: 46s; animation-direction: reverse; }
.vortex-ring.r3{ width: 56%; height: 56%; border-color: rgba(18,58,92,.4); animation-duration: 30s; }
.vortex-ring.r4{ width: 36%; height: 36%; border-style: dashed; border-color: rgba(20,108,122,.5); animation-duration: 18s; animation-direction: reverse; }
.vortex-core{
  position: relative;
  width: 62%;
  z-index: 2;
  filter: drop-shadow(0 18px 30px rgba(10,46,56,.25));
}
@keyframes spin{ to{ transform: rotate(360deg); } }
@media (prefers-reduced-motion: reduce){
  .vortex-ring{ animation: none; }
}

/* ---------- stat strip ---------- */
.stat-strip{
  background: var(--ink);
  color: #fff;
}
.stat-strip .wrap{
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  padding: 2.4rem 32px;
  gap: 1.5rem;
}
.stat{
  border-left: 1px solid rgba(255,255,255,.16);
  padding-left: 1.3rem;
}
.stat:first-child{ border-left: none; padding-left: 0; }
.stat .num{
  font-family: var(--mono);
  font-size: 1.7rem;
  color: #fff;
  display: block;
}
.stat .label{
  font-size: .82rem;
  color: rgba(255,255,255,.62);
  margin-top: .3em;
  line-height: 1.4;
}

/* ---------- sections ---------- */
section{ padding: 5rem 0; }
.section-tight{ padding: 3.4rem 0; }
.bg-alt{ background: var(--bg-alt); }
.bg-paper{ background: var(--paper); }

.two-col{
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3.5rem;
  align-items: start;
}
.two-col.reverse{ direction: rtl; }
.two-col.reverse > *{ direction: ltr; }

.lead-col p:first-of-type{
  font-size: 1.15rem;
  color: var(--ink);
}

figure{ margin: 0; }
figure img{
  border-radius: 6px;
  border: 1px solid var(--line-soft);
}

.video-embed{
  position: relative;
  width: 100%;
  padding-top: 56.25%; /* 16:9 */
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid var(--line-soft);
  background: var(--ink);
}
.video-embed iframe{
  position: absolute;
  top: 0; left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}
figcaption{
  font-family: var(--mono);
  font-size: .78rem;
  color: var(--muted);
  margin-top: .8em;
  padding-left: .8em;
  border-left: 2px solid var(--accent);
}

blockquote{
  font-family: var(--display);
  font-style: italic;
  font-size: 1.3rem;
  line-height: 1.45;
  color: var(--deep);
  margin: 1.6em 0;
  padding-left: 1.1em;
  border-left: 3px solid var(--teal);
}
blockquote cite{
  display: block;
  font-family: var(--mono);
  font-style: normal;
  font-size: .78rem;
  color: var(--muted);
  margin-top: .8em;
}

.card-grid{
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.6rem;
}
.card{
  background: var(--paper);
  border: 1px solid var(--line-soft);
  border-radius: 8px;
  padding: 1.8rem;
}
.card .idx{
  font-family: var(--mono);
  font-size: .75rem;
  color: var(--accent);
  display:block;
  margin-bottom: .8em;
}

/* page header (non-home pages) */
.page-header{
  padding: 3.6rem 0 2.6rem;
  border-bottom: 1px solid var(--line-soft);
  background:
    radial-gradient(ellipse at top right, rgba(20,108,122,.10), transparent 55%),
    var(--bg);
}
.page-header h1{ font-size: clamp(2rem, 3.6vw, 2.9rem); }
.page-header .lede{ color: var(--muted); max-width: 62ch; font-size: 1.05rem; }

/* advisors */
.advisor-list{
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.4rem 2.4rem;
}
.advisor{
  padding: 1.6rem 0;
  border-top: 1px solid var(--line-soft);
}
.advisor:nth-child(-n+2){ border-top: none; padding-top: 0; }
.advisor h3{ margin-bottom: .3em; }
.advisor .role{
  font-family: var(--mono);
  font-size: .78rem;
  color: var(--teal-dim);
  display: block;
  margin-bottom: .6em;
}
.partner-logos{
  display: flex;
  align-items: center;
  gap: 3rem;
  flex-wrap: wrap;
  padding-top: 1rem;
}
.partner-logos img{ height: 65px; width: auto; opacity: .9; } /* 25% larger than original 52px */

/* technology page extras */
.download-card{
  display: flex;
  gap: 1.4rem;
  align-items: center;
  background: var(--paper);
  border: 1px solid var(--line-soft);
  border-radius: 8px;
  padding: 1.4rem;
  margin: 1.6rem 0 2rem;
}
.download-card img{
  width: 74px;
  border: 1px solid var(--line-soft);
  border-radius: 4px;
}
.download-card .meta{ font-family: var(--mono); font-size: .78rem; color: var(--muted); margin-top:.4em; }

/* contact page */
.contact-grid{
  display: grid;
  grid-template-columns: .85fr 1.15fr;
  gap: 3.5rem;
}
.contact-info dl{
  margin: 1.6rem 0 0;
}
.contact-info dt{
  font-family: var(--mono);
  font-size: .72rem;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--muted);
  margin-top: 1.2em;
}
.contact-info dd{
  margin: .25em 0 0;
  font-size: 1.02rem;
}
.contact-info a{ text-decoration: none; color: var(--teal-dim); border-bottom: 1px solid var(--line); }

.field{ margin-bottom: 1.3rem; }
.field label{
  display: block;
  font-family: var(--mono);
  font-size: .74rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--muted);
  margin-bottom: .5em;
}
.field input, .field textarea{
  width: 100%;
  font-family: var(--body);
  font-size: 1rem;
  padding: .8em .9em;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: var(--paper);
  color: var(--ink);
}
.field input:focus, .field textarea:focus{
  border-color: var(--teal);
}
.field textarea{ resize: vertical; min-height: 120px; }
.form-note{
  font-size: .85rem;
  color: var(--muted);
  margin-top: 1em;
}
.form-status{
  display:none;
  margin-top: 1em;
  padding: .9em 1.1em;
  border-radius: 5px;
  background: var(--bg-alt);
  border: 1px solid var(--line-soft);
  font-size: .92rem;
}
.form-status.visible{ display:block; }

/* ---------- CTA band ---------- */
.cta-band{
  background: var(--deep);
  color: #fff;
  text-align: center;
}
.cta-band h2{ color: #fff; }
.cta-band p{ color: rgba(255,255,255,.72); max-width: 56ch; margin-left:auto; margin-right:auto; }

/* ---------- footer ---------- */
.site-footer{
  background: var(--ink);
  color: rgba(255,255,255,.7);
  padding: 3rem 0 2.2rem;
}
.footer-top{
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid rgba(255,255,255,.14);
}
.footer-brand{ display:flex; align-items:center; gap:.7em; }
.footer-brand img{ height: 30px; filter: brightness(0) invert(1); opacity:.92; }
.footer-nav ul{
  list-style:none; display:flex; gap:1.8em; margin:0; padding:0; flex-wrap: wrap;
}
.footer-nav a{ text-decoration:none; color: rgba(255,255,255,.75); font-size:.92rem; }
.footer-nav a:hover{ color:#fff; }
.footer-bottom{
  display:flex; justify-content:space-between; align-items:center; flex-wrap:wrap; gap:1em;
  padding-top: 1.6rem;
  font-size: .82rem;
  color: rgba(255,255,255,.5);
}
.footer-bottom .mono{ font-family: var(--mono); }

/* ---------- responsive ---------- */
@media (max-width: 900px){
  .hero .wrap{ grid-template-columns: 1fr; padding-top: 2.6rem; }
  .vortex-stage{ order: -1; max-width: 320px; margin: 0 auto; }
  .stat-strip .wrap{ grid-template-columns: repeat(2,1fr); }
  .stat{ border-left:none; padding-left:0; }
  .two-col, .contact-grid{ grid-template-columns: 1fr; gap: 2rem; }
  .card-grid{ grid-template-columns: 1fr 1fr; }
  .advisor-list{ grid-template-columns: 1fr; }
  .advisor:nth-child(2){ border-top: 1px solid var(--line-soft); padding-top: 1.6rem; }

  .main-nav{
    position: absolute;
    top: 84px; left:0; right:0;
    background: var(--paper);
    border-bottom: 1px solid var(--line-soft);
    display: none;
  }
  .main-nav.open{ display:block; }
  .main-nav ul{ flex-direction: column; gap:0; padding: 1rem 32px 1.4rem; }
  .main-nav a{ display:block; padding: .9em 0; border-bottom: 1px solid var(--line-soft) !important; }
  .nav-toggle{ display:flex; }
}
@media (max-width: 560px){
  .card-grid{ grid-template-columns: 1fr; }
  .site-header .wrap{ height: 72px; }
  section{ padding: 3.2rem 0; }
}