/* =========================================================
   expertfea.com — design system
   Modern, technical aesthetic for engineering / biomechanics
   students & professionals. Vanilla CSS, no framework.
   ========================================================= */

:root{
  --navy-950:#0a0e17;
  --navy-900:#0f1522;
  --navy-800:#151d2e;
  --navy-700:#1d2740;
  --navy-600:#28365a;
  --line:#26314a;
  --paper:#faf5ff;
  --paper-2:#f1e9fb;
  --ink:#141922;
  --ink-soft:#4b5468;
  --cyan:#2fd0d8;
  --cyan-dark:#12a3ab;
  --orange:#ff7a33;
  --green:#33c17a;
  --purple:#9b7bf0;
  --white:#ffffff;
  --radius:12px;
  --radius-sm:8px;
  --shadow-sm:0 1px 2px rgba(10,14,23,.06), 0 1px 1px rgba(10,14,23,.04);
  --shadow-md:0 8px 24px rgba(10,14,23,.10), 0 2px 6px rgba(10,14,23,.06);
  --shadow-lg:0 20px 50px rgba(10,14,23,.16);
  --maxw:1180px;
  --font-body:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;
  --font-mono:'JetBrains Mono','SFMono-Regular',Consolas,'Liberation Mono',Menlo,monospace;
}

*,*::before,*::after{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;
  font-family:var(--font-body);
  color:var(--ink);
  background:
    linear-gradient(var(--paper),var(--paper)),
    repeating-linear-gradient(0deg, rgba(20,25,34,.028) 0 1px, transparent 1px 96px),
    repeating-linear-gradient(90deg, rgba(20,25,34,.028) 0 1px, transparent 1px 96px);
  background-attachment:fixed;
  -webkit-font-smoothing:antialiased;
  line-height:1.55;
}
img{max-width:100%;height:auto;display:inline-block;vertical-align:middle;}
.card-media img,.slider .slide img{display:block;}
a{color:var(--cyan-dark);text-decoration:none;}
a:hover{color:var(--navy-800);}
hr{border:none;border-top:1px solid var(--line);margin:2rem 0;}
h1,h2,h3,h4{
  font-family:var(--font-body);
  font-weight:800;
  color:var(--navy-950);
  line-height:1.2;
  letter-spacing:-.01em;
}
.container{max-width:var(--maxw);margin:0 auto;padding:0 20px;}
.eyebrow{
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.14em;
  text-transform:uppercase;
  color:var(--cyan-dark);
  font-weight:700;
}

/* ---------- Top bar ---------- */
.topbar{
  background:var(--navy-950);
  color:#9fb0c9;
  font-family:var(--font-mono);
  font-size:.78rem;
}
.topbar .container{
  display:flex;justify-content:space-between;align-items:center;
  padding-top:7px;padding-bottom:7px;flex-wrap:wrap;gap:6px;
}
.topbar a{color:#cfe0f0;}
.topbar a:hover{color:var(--cyan);}

/* ---------- Header / Nav ---------- */
header.site-header{
  background:var(--navy-900);
  position:sticky;top:0;z-index:100;
  box-shadow:0 2px 18px rgba(0,0,0,.25);
}
.nav-row{
  display:flex;align-items:center;justify-content:space-between;
  padding:14px 0;
}
.brand{
  display:flex;align-items:center;gap:10px;
  font-weight:800;font-size:1.15rem;color:var(--white);
}
.brand .mark{
  width:34px;height:34px;border-radius:8px;
  background:linear-gradient(135deg,var(--cyan),var(--purple));
  display:flex;align-items:center;justify-content:center;
  font-family:var(--font-mono);font-weight:800;color:var(--navy-950);font-size:.85rem;
  flex:none;
}
.brand span.tag{color:#7c8aa5;font-weight:500;font-size:.7rem;font-family:var(--font-mono);display:block;letter-spacing:.06em;}
.navbar-toggle{
  display:none;background:none;border:1px solid var(--line);color:var(--white);
  border-radius:8px;padding:8px 10px;cursor:pointer;
}
.navbar-toggle span{display:block;width:20px;height:2px;background:#cfe0f0;margin:4px 0;border-radius:2px;}
nav.mainnav ul{
  list-style:none;display:flex;gap:2px;margin:0;padding:0;flex-wrap:wrap;
}
nav.mainnav a{
  color:#c3cfe3;font-size:1rem;font-weight:600;padding:9px 13px;border-radius:8px;
  display:inline-block;white-space:nowrap;
}
nav.mainnav a:hover{background:var(--navy-700);color:var(--white);}
nav.mainnav a.active{background:var(--navy-700);color:var(--cyan);}
nav.mainnav a.accent-green{color:#7fe0ac;}
nav.mainnav a.accent-purple{color:#c6b3fb;}

/* ---------- Hero / page header ---------- */
.page-hero{
  background:
    radial-gradient(1100px 380px at 15% -10%, rgba(47,208,216,.16), transparent 60%),
    radial-gradient(900px 340px at 100% 0%, rgba(155,123,240,.14), transparent 55%),
    var(--navy-950);
  color:#eef2f8;
  padding:52px 0 40px;
  border-bottom:1px solid var(--navy-700);
}
.page-hero h1{
  color:var(--white);
  font-size:clamp(1.6rem,3.4vw,2.5rem);
  margin:.2em 0 .35em;
}
.page-hero p.lead{
  color:#aebbd2;font-size:1.05rem;max-width:760px;margin:0;
}
.page-hero .stats{display:flex;gap:26px;flex-wrap:wrap;margin-top:20px;}
.page-hero .stat b{font-family:var(--font-mono);color:var(--cyan);font-size:1.25rem;display:block;}
.page-hero .stat span{font-size:.76rem;color:#8fa0ba;text-transform:uppercase;letter-spacing:.06em;}

/* ---------- Breadcrumb / page nav (prev/next) ---------- */
.page-nav{
  display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;
  margin:22px 0;
}
.page-nav a{
  font-size:.85rem;font-weight:700;color:var(--navy-800);
  background:var(--white);border:1px solid var(--paper-2);
  padding:9px 16px;border-radius:999px;box-shadow:var(--shadow-sm);
}
.page-nav a:hover{border-color:var(--cyan-dark);color:var(--cyan-dark);}

/* ---------- Section ---------- */
.section{padding:34px 0;}
.section-title{
  text-align:center;margin:6px 0 8px;font-size:clamp(1.3rem,2.6vw,1.9rem);
}
.section-sub{text-align:center;color:var(--ink-soft);max-width:720px;margin:0 auto 26px;font-size:1.02rem;}

/* ---------- Card grid ---------- */
.grid{
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:22px;
  margin:20px 0;
}
@media (max-width:900px){.grid{grid-template-columns:repeat(2,1fr);}}
@media (max-width:620px){.grid{grid-template-columns:1fr;}}

.card{
  background:var(--white);
  border:1px solid var(--paper-2);
  border-radius:var(--radius);
  overflow:hidden;
  box-shadow:var(--shadow-sm);
  transition:transform .18s ease, box-shadow .18s ease, border-color .18s ease;
  display:flex;flex-direction:column;
  text-align:center;
}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-md);border-color:#d7dee8;}
.card .card-media{
  background:var(--navy-950);
  display:flex;align-items:center;justify-content:center;
  aspect-ratio:4/3;overflow:hidden;
}
.card .card-media img{width:100%;height:100%;object-fit:cover;}
.card .card-body{padding:16px 18px 20px;display:flex;flex-direction:column;gap:10px;flex:1;}
.card h3{font-size:1rem;margin:0;line-height:1.35;}
.card p{margin:0;color:var(--ink-soft);font-size:.92rem;}
.card p small{font-size:.86rem;}
.card .card-actions{margin-top:auto;display:flex;flex-direction:column;gap:8px;padding-top:6px;}

/* ---------- Buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  font-weight:700;font-size:.88rem;
  padding:10px 18px;border-radius:999px;
  background:var(--navy-900);color:var(--white)!important;
  border:1px solid var(--navy-900);
  cursor:pointer;transition:all .15s ease;
}
.btn:hover{background:var(--cyan-dark);border-color:var(--cyan-dark);color:var(--navy-950)!important;}
.btn-outline{background:transparent;color:var(--navy-900)!important;border:1px solid var(--line);}
.btn-outline:hover{background:var(--navy-900);color:var(--white)!important;}
.btn-buy{
  background:var(--orange);border-color:var(--orange);color:#241000!important;
  display:flex;width:max-content;
  margin:10px auto 4px;
  padding:8.5px 15px;font-size:.85rem;
}
.btn-buy:hover{background:#e0611c;border-color:#e0611c;color:#fff!important;}
.btn-buy img{display:none;} /* hide legacy paypal graphic, styled button used instead */
.btn-lg{
  padding:11px 22px;font-size:.95rem;
  display:flex;width:max-content;margin:10px auto 4px;
}
del{opacity:.55;margin-right:6px;}

/* small inline purchase lines kept from original markup */
.buyline{
  background:var(--paper-2);border:1px solid #e3e7ee;border-radius:var(--radius-sm);
  padding:12px 16px;margin:10px 0;font-size:.94rem;display:flex;align-items:center;gap:10px;flex-wrap:wrap;
}
.buyline a.btn{margin-left:auto;}

/* ---------- Prose / detail pages ---------- */
.prose{max-width:820px;margin:0 auto;}
.prose h1,.prose h2,.prose h3{margin-top:1.4em;}
.prose p{font-size:1.02rem;color:#26303f;}
.prose ul{padding-left:1.2em;}
.prose li{margin:.35em 0;}
.disclaimer{
  background:var(--navy-950);color:#b9c4d8;border-radius:var(--radius);
  padding:22px 26px;font-size:.86rem;line-height:1.7;margin:30px 0;
}
.disclaimer strong{color:var(--white);}

/* ---------- Gallery / slider ---------- */
.slider{
  position:relative;background:var(--navy-950);border-radius:var(--radius);
  overflow:hidden;box-shadow:var(--shadow-md);margin:20px 0;
}
.slider .slides{display:flex;transition:transform .3s ease;}
.slider .slide{flex:0 0 100%;display:flex;align-items:center;justify-content:center;min-height:220px;}
.slider .slide img{width:100%;max-height:560px;object-fit:contain;}
.slider .ctrl{
  position:absolute;top:50%;transform:translateY(-50%);
  background:rgba(10,14,23,.55);color:#fff;border:none;
  width:42px;height:42px;border-radius:50%;font-size:1.2rem;cursor:pointer;
  display:flex;align-items:center;justify-content:center;
}
.slider .ctrl:hover{background:var(--cyan-dark);}
.slider .prev{left:12px;}
.slider .next{right:12px;}
.slider .dots{position:absolute;bottom:10px;left:0;right:0;display:flex;gap:6px;justify-content:center;}
.slider .dots button{width:7px;height:7px;border-radius:50%;border:none;background:rgba(255,255,255,.35);padding:0;cursor:pointer;}
.slider .dots button.active{background:var(--cyan);}

/* ---------- Form ---------- */
.contact-card{
  background:var(--white);border:1px solid var(--paper-2);border-radius:var(--radius);
  padding:26px 28px;box-shadow:var(--shadow-sm);max-width:640px;margin:0 auto 30px;text-align:center;
}
.contact-card a{font-weight:700;}

/* ---------- Timeline (news/updates on contact page) ---------- */
.timeline{max-width:820px;margin:0 auto;}
.timeline .year-marker{
  font-family:var(--font-mono);font-weight:800;color:var(--navy-950);
  font-size:1.1rem;margin:34px 0 10px;padding-top:10px;border-top:2px solid var(--navy-950);
}
.timeline ul{list-style:none;padding:0;margin:0;}
.timeline li{
  padding:10px 0 10px 22px;border-left:2px solid var(--paper-2);position:relative;font-size:.95rem;
}
.timeline li::before{
  content:'';position:absolute;left:-6px;top:16px;width:10px;height:10px;border-radius:50%;
  background:var(--cyan);border:2px solid var(--paper);
}
.timeline li b{color:var(--navy-950);}

/* ---------- Footer ---------- */
footer.site-footer{
  background:var(--navy-950);color:#8fa0ba;margin-top:50px;
  padding:34px 0;font-size:.85rem;
}
footer.site-footer .container{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:12px;}
footer.site-footer a{color:#cfe0f0;}

/* ---------- Utility ---------- */
.text-center{text-align:center;}
.mt-0{margin-top:0;}
.badge{
  display:inline-block;font-family:var(--font-mono);font-size:.72rem;font-weight:700;
  background:var(--paper-2);color:var(--navy-800);border-radius:999px;padding:4px 10px;
}
.badge-green{background:#e2f8ec;color:#127a45;}
.badge-purple{background:#efe9fd;color:#6339c9;}

/* ---------- Responsive nav ---------- */
@media (max-width:980px){
  .navbar-toggle{display:inline-block;}
  nav.mainnav{
    display:none;width:100%;order:3;
    background:var(--navy-900);border-top:1px solid var(--navy-700);
    margin-top:12px;
  }
  nav.mainnav.open{display:block;}
  nav.mainnav ul{flex-direction:column;padding:8px 0;}
  nav.mainnav a{display:block;padding:12px 6px;border-radius:6px;}
  .nav-row{flex-wrap:wrap;}
}