/* Briti Scientific — CSS System (ready to drop into site)
   Contains: CSS variables, base typography, layout helpers, components (nav, hero, cards, buttons, forms, footer)
   Usage: include this stylesheet after your main styles or adapt variables to your theme file.
*/

:root{
  /* Brand colors */
  --bs-purple: #422874;
  --bs-purple-2: #6C55A3;
  --bs-yellow: #FAB928;

  /* Neutrals */
  --bs-bg: #F7F7FA;
  --bs-surface: #FFFFFF;
  --bs-muted: #D1D1E0;
  --bs-text: #2A2A2A;
  --bs-contrast: rgba(0,0,0,0.85);

  /* Spacing & radius */
  --bs-gap-xs: 6px;
  --bs-gap-sm: 12px;
  --bs-gap: 18px;
  --bs-gap-lg: 28px;
  --bs-radius: 10px;

  /* Shadows */
  --bs-shadow-1: 0 6px 18px rgba(66,40,116,0.08);
  --bs-shadow-2: 0 14px 30px rgba(66,40,116,0.12);

  /* Type scale */
  --bs-font-sans: "Inter", "Poppins", system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  --bs-h1: 2rem; /* adjust as needed */
  --bs-h2: 1.125rem;
  --bs-body: 1rem;

  /* Breakpoints */
  --bs-break-sm: 640px;
  --bs-break-md: 1000px;
}

/* Basic reset & base */
*{box-sizing:border-box}
html,body{height:100%;font-family:var(--bs-font-sans);margin:0;padding:0;background:var(--bs-bg);color:var(--bs-text);-webkit-font-smoothing:antialiased}
a{color:var(--bs-purple);text-decoration:none}
.container{max-width:1100px;margin:0 auto;padding:28px}

/* Accessibility helpers */
.visually-hidden{position:absolute!important;height:1px;width:1px;overflow:hidden;clip:rect(1px,1px,1px,1px);white-space:nowrap;border:0;padding:0;margin:-1px}

/* Header / Nav */
.site-header{background:linear-gradient(180deg,var(--bs-purple),var(--bs-purple-2));color:var(--bs-surface);position:sticky;top:0;z-index:50;box-shadow:0 2px 8px rgba(0,0,0,0.08)}
.site-header .nav{display:flex;align-items:center;justify-content:space-between;padding:14px 20px}
.site-header .brand{display:flex;align-items:center;gap:12px;font-weight:700}
.brand .logo-mark{width:44px;height:44px;border-radius:8px;background:linear-gradient(135deg,var(--bs-purple),var(--bs-purple-2));display:flex;align-items:center;justify-content:center;font-size:18px;color:var(--bs-yellow);box-shadow:0 4px 12px rgba(66,40,116,0.12)}
.main-nav{display:flex;gap:16px;align-items:center}
.main-nav a{color:var(--bs-surface);padding:8px 10px;border-radius:6px;transition:background .18s,color .18s}
.main-nav a:hover{background:rgba(255,255,255,0.06);color:var(--bs-yellow)}

/* Buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border-radius:8px;padding:10px 14px;font-weight:600;cursor:pointer;border:0}
.btn-primary{background:var(--bs-yellow);color:var(--bs-purple);box-shadow:0 6px 14px rgba(250,185,40,0.12)}
.btn-outline{background:var(--bs-surface);color:var(--bs-purple);border:2px solid var(--bs-purple)}

/* Hero */
.hero{padding:64px 0;color:var(--bs-surface);background:linear-gradient(90deg, rgba(66,40,116,0.95), rgba(108,85,163,0.9));background-size:cover}
.hero .hero-inner{display:grid;grid-template-columns:1fr 420px;gap:28px;align-items:center;max-width:1100px;margin:0 auto;padding:0 20px}
.hero h1{font-size:var(--bs-h1);line-height:1.04;margin-bottom:12px}
.hero p.lead{opacity:0.95;margin-bottom:16px}

/* Cards & surfaces */
.card{background:var(--bs-surface);border-radius:var(--bs-radius);padding:16px;border:1px solid var(--bs-muted);box-shadow:var(--bs-shadow-1)}
.feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.product-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.product-card{display:flex;flex-direction:column;gap:12px;transition:transform .18s,box-shadow .18s}
.product-card:hover{transform:translateY(-6px);box-shadow:var(--bs-shadow-2);border-color:var(--bs-purple-2)}
.product-image{height:140px;border-radius:8px;background:linear-gradient(135deg,var(--bs-muted),#fff);display:flex;align-items:center;justify-content:center;color:var(--bs-purple);font-weight:700}

/* Product detail layout */
.product-detail{display:grid;grid-template-columns:420px 1fr;gap:22px;align-items:start}
.specs{background:var(--bs-surface);padding:16px;border-radius:10px;border:1px solid var(--bs-muted);box-shadow:var(--bs-shadow-1)}
.badge{display:inline-block;padding:6px 8px;border-radius:6px;background:var(--bs-yellow);color:var(--bs-purple);font-weight:700;margin-right:8px}

/* Tabs */
.tabs{display:flex;gap:8px;border-bottom:1px solid var(--bs-muted);padding-bottom:8px;margin-bottom:12px}
.tab{padding:8px 10px;border-radius:8px;color:var(--bs-purple);cursor:pointer}

/* About / Timeline */
.about-grid{display:grid;grid-template-columns:1fr 380px;gap:22px;align-items:start}
.timeline{background:linear-gradient(90deg, rgba(250,185,40,0.08), rgba(66,40,116,0.02));padding:12px;border-radius:10px;border:1px solid var(--bs-muted)}
.timeline li{list-style:none;padding:12px 0;position:relative}
.timeline li:before{content:'';width:12px;height:12px;background:var(--bs-yellow);border-radius:50%;position:absolute;left:-22px;top:12px;box-shadow:0 4px 10px rgba(250,185,40,0.18)}

/* Forms */
.form-row{display:flex;flex-direction:column;gap:8px;margin-bottom:10px}
.form-row input,.form-row textarea{padding:12px;border-radius:8px;border:1px solid var(--bs-muted);outline:none}
.form-row input:focus,.form-row textarea:focus{border-color:var(--bs-purple);box-shadow:0 8px 20px rgba(66,40,116,0.06)}

/* Footer */
.site-footer{background:linear-gradient(180deg,var(--bs-purple),#2D2440);color:var(--bs-surface);padding:36px 0;margin-top:40px}
.footer-grid{display:grid;grid-template-columns:1fr 220px 220px;gap:18px;align-items:start}
.site-footer a{color:var(--bs-surface)}
.site-footer a:hover{color:var(--bs-yellow)}

/* Utilities */
.row{display:flex;gap:12px}
.center{display:flex;align-items:center;justify-content:center}
.hstack{display:flex;align-items:center;gap:12px}

/* Responsive */
@media (max-width:1000px){
  .hero .hero-inner{grid-template-columns:1fr 320px}
  .product-grid{grid-template-columns:repeat(2,1fr)}
  .feature-grid{grid-template-columns:repeat(2,1fr)}
  .about-grid{grid-template-columns:1fr}
  .product-detail{grid-template-columns:1fr}
}
@media (max-width:640px){
  .main-nav{display:none}
  .hero{padding:44px 0}
  .hero h1{font-size:1.5rem}
  .hero .hero-inner{grid-template-columns:1fr;padding:0 12px}
  .product-grid{grid-template-columns:1fr}
  .feature-grid{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
}