/* ==========================================================================
   Vayustar Tech — shared design system
   System-font stack only (zero render-blocking web-font request → better LCP).
   ========================================================================== */

:root {
  --navy-900: #061d30;
  --navy-800: #0a3d62;
  --navy-700: #0e4d7a;
  --navy-600: #1e6091;
  --cyan-500: #12b5cb;
  --cyan-400: #2fc6da;
  --ink: #16222e;
  --body: #41525f;
  --muted: #6b7a87;
  --line: #e6ebef;
  --line-2: #eef2f5;
  --bg: #ffffff;
  --bg-soft: #f6f9fb;
  --bg-tint: #e8f1f8;
  --white: #ffffff;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow-sm: 0 1px 2px rgba(6, 29, 48, 0.06);
  --shadow: 0 12px 32px rgba(6, 29, 48, 0.08);
  --shadow-lg: 0 24px 60px rgba(6, 29, 48, 0.14);
  --maxw: 1140px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font);
  line-height: 1.65;
  color: var(--body);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg { max-width: 100%; height: auto; display: block; }

a { color: var(--navy-700); text-decoration: none; transition: color .15s ease; }
a:hover { color: var(--cyan-500); }

h1, h2, h3, h4 { color: var(--ink); line-height: 1.18; letter-spacing: -0.02em; font-weight: 700; }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.narrow { max-width: 820px; }

/* Accessibility ----------------------------------------------------------- */
:focus-visible { outline: 3px solid var(--cyan-500); outline-offset: 2px; border-radius: 4px; }
.skip-link {
  position: absolute; left: -999px; top: 0; z-index: 1000;
  background: var(--navy-800); color: #fff; padding: 10px 16px; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; color: #fff; }
.visually-hidden {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

/* Buttons ----------------------------------------------------------------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 28px; border-radius: var(--radius-sm); font-weight: 600; font-size: 16px;
  cursor: pointer; border: 2px solid transparent; transition: transform .15s ease, box-shadow .15s ease, background .15s ease, color .15s ease;
}
.btn-primary { background: var(--cyan-500); color: #04222a; }
.btn-primary:hover { background: var(--cyan-400); color: #04222a; transform: translateY(-1px); box-shadow: 0 10px 24px rgba(18, 181, 203, .28); }
.btn-light { background: #fff; color: var(--navy-800); }
.btn-light:hover { color: var(--navy-800); transform: translateY(-1px); box-shadow: var(--shadow); }
.btn-outline { background: transparent; color: #fff; border-color: rgba(255,255,255,.45); }
.btn-outline:hover { background: rgba(255,255,255,.12); color: #fff; }
.btn-ghost { background: transparent; color: var(--navy-700); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--cyan-500); color: var(--cyan-500); }

/* Header / nav ------------------------------------------------------------ */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.9); backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.site-header .container { display: flex; align-items: center; justify-content: space-between; min-height: 68px; }
.brand { display: inline-flex; align-items: center; }
.brand img { height: 34px; }
.nav-links { display: flex; align-items: center; gap: 26px; }
.nav-links a { color: var(--body); font-size: 15px; font-weight: 500; }
.nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--navy-800); }
.nav-links a.login { padding: 8px 18px; border: 1.5px solid var(--navy-800); border-radius: 6px; color: var(--navy-800); font-weight: 600; }
.nav-links a.login:hover { background: var(--navy-800); color: #fff; }
.nav-links a.cta { padding: 9px 18px; background: var(--cyan-500); color: #04222a; border-radius: 6px; font-weight: 600; }
.nav-links a.cta:hover { background: var(--cyan-400); color: #04222a; }
.nav-toggle { display: none; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--ink); margin: 4px 0; border-radius: 2px; }

/* Hero -------------------------------------------------------------------- */
.hero {
  background: radial-gradient(1200px 500px at 80% -10%, #15517e 0%, transparent 60%),
              linear-gradient(135deg, var(--navy-800) 0%, var(--navy-600) 100%);
  color: #fff; padding: 96px 0 88px;
}
.hero .eyebrow { color: var(--cyan-400); font-weight: 600; letter-spacing: .08em; text-transform: uppercase; font-size: 13px; margin-bottom: 18px; }
.hero h1 { color: #fff; font-size: clamp(34px, 5vw, 52px); max-width: 800px; margin-bottom: 22px; }
.hero p.sub { font-size: clamp(17px, 2.2vw, 20px); color: rgba(255,255,255,.9); max-width: 660px; margin-bottom: 34px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; }
.hero-sub { background: linear-gradient(135deg, var(--navy-800) 0%, var(--navy-700) 100%); color: #fff; padding: 70px 0 60px; }
.hero-sub h1 { color: #fff; font-size: clamp(30px, 4.5vw, 44px); max-width: 820px; margin-bottom: 16px; }
.hero-sub p { color: rgba(255,255,255,.9); font-size: 19px; max-width: 680px; }

/* Breadcrumb -------------------------------------------------------------- */
.crumbs { font-size: 13px; color: rgba(255,255,255,.7); margin-bottom: 18px; }
.crumbs a { color: rgba(255,255,255,.85); }
.crumbs a:hover { color: #fff; }
.crumbs span { margin: 0 8px; opacity: .6; }

/* Sections ---------------------------------------------------------------- */
.section { padding: 88px 0; }
.section.soft { background: var(--bg-soft); }
.section.navy { background: var(--navy-800); color: rgba(255,255,255,.88); }
.section-head { max-width: 720px; margin-bottom: 52px; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.eyebrow { color: var(--cyan-500); font-weight: 700; letter-spacing: .08em; text-transform: uppercase; font-size: 13px; margin-bottom: 12px; }
.section h2 { font-size: clamp(28px, 3.6vw, 38px); margin-bottom: 16px; }
.section .lead { font-size: 18px; color: var(--muted); line-height: 1.6; }
.section.navy h2 { color: #fff; }
.section.navy .eyebrow { color: var(--cyan-400); }
.section.navy .lead { color: rgba(255,255,255,.75); }

/* Cards ------------------------------------------------------------------- */
.grid { display: grid; gap: 26px; }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }

.card {
  padding: 30px 28px; border: 1px solid var(--line); border-radius: var(--radius);
  background: #fff; transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: #d8e3ec; }
.card .icon {
  width: 46px; height: 46px; border-radius: 10px; background: var(--bg-tint);
  display: flex; align-items: center; justify-content: center; margin-bottom: 18px;
  color: var(--navy-800); font-weight: 700; font-size: 16px;
}
.card h3 { color: var(--navy-800); margin-bottom: 10px; font-size: 20px; }
.card p { color: var(--body); font-size: 15px; }
.card a.more { display: inline-block; margin-top: 14px; color: var(--cyan-500); font-weight: 600; font-size: 15px; }
.card a.more:hover { color: var(--navy-700); }

/* Prose ------------------------------------------------------------------- */
.prose p { font-size: 17px; color: var(--body); margin-bottom: 18px; max-width: 760px; }
.prose h2 { font-size: clamp(24px, 3vw, 32px); margin: 44px 0 16px; }
.prose h3 { font-size: 21px; margin: 30px 0 12px; color: var(--navy-800); }
.prose ul { margin: 0 0 20px 0; padding-left: 0; list-style: none; max-width: 760px; }
.prose ul li { position: relative; padding-left: 30px; margin-bottom: 12px; font-size: 17px; color: var(--body); }
.prose ul li::before {
  content: ""; position: absolute; left: 6px; top: 11px; width: 8px; height: 8px;
  border-right: 2px solid var(--cyan-500); border-bottom: 2px solid var(--cyan-500);
  transform: rotate(45deg);
}

/* Stats / trust ----------------------------------------------------------- */
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 28px; }
.stat { padding: 20px 0; border-top: 3px solid var(--cyan-500); }
.stat .num { font-size: 38px; font-weight: 700; color: var(--navy-800); line-height: 1; }
.stat .label { color: var(--muted); font-size: 14px; margin-top: 8px; }

.trust-band { display: flex; flex-wrap: wrap; gap: 12px; }
.cert-pill {
  display: inline-flex; align-items: center; gap: 8px; padding: 9px 16px;
  background: #fff; border: 1px solid var(--line); border-radius: 999px;
  font-size: 14px; color: var(--ink); font-weight: 500;
}
.cert-pill::before { content: "✓"; color: var(--cyan-500); font-weight: 700; }
.section.navy .cert-pill { background: rgba(255,255,255,.06); border-color: rgba(255,255,255,.16); color: #fff; }

/* FAQ --------------------------------------------------------------------- */
.faq { max-width: 820px; }
.faq details {
  border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 0; margin-bottom: 14px; background: #fff;
}
.faq summary {
  cursor: pointer; list-style: none; padding: 20px 24px; font-weight: 600; color: var(--ink);
  font-size: 17px; display: flex; justify-content: space-between; align-items: center; gap: 16px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--cyan-500); font-size: 24px; font-weight: 400; line-height: 1; }
.faq details[open] summary::after { content: "–"; }
.faq details p { padding: 0 24px 22px; color: var(--body); font-size: 16px; margin: 0; }

/* CTA band ---------------------------------------------------------------- */
.cta-band { background: linear-gradient(135deg, var(--navy-800) 0%, var(--navy-600) 100%); color: #fff; padding: 72px 0; text-align: center; }
.cta-band h2 { color: #fff; font-size: clamp(26px, 3.4vw, 36px); margin-bottom: 14px; }
.cta-band p { color: rgba(255,255,255,.86); font-size: 18px; max-width: 600px; margin: 0 auto 28px; }

/* Contact ----------------------------------------------------------------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: start; }
.field { margin-bottom: 18px; }
.field label { display: block; font-weight: 600; color: var(--ink); margin-bottom: 7px; font-size: 14px; }
.field input, .field textarea, .field select {
  width: 100%; padding: 12px 14px; border: 1.5px solid var(--line); border-radius: var(--radius-sm);
  font-family: inherit; font-size: 15px; color: var(--ink); background: #fff; transition: border-color .15s ease;
}
.field input:focus, .field textarea:focus, .field select:focus { border-color: var(--cyan-500); outline: none; }
.field textarea { resize: vertical; min-height: 130px; }
.field .err { color: #c0392b; font-size: 13px; margin-top: 5px; display: none; }
.field.invalid input, .field.invalid textarea { border-color: #c0392b; }
.field.invalid .err { display: block; }
.hp { position: absolute; left: -9999px; opacity: 0; height: 0; width: 0; overflow: hidden; }
.form-status { margin-top: 14px; font-size: 15px; font-weight: 500; }
.contact-aside .contact-item { margin-bottom: 26px; }
.contact-aside .contact-item strong { display: block; text-transform: uppercase; letter-spacing: .1em; font-size: 12px; color: var(--muted); margin-bottom: 6px; }
.contact-aside .contact-item a, .contact-aside .contact-item span { color: var(--ink); font-size: 17px; }

/* Footer ------------------------------------------------------------------ */
.site-footer { background: var(--navy-900); color: rgba(255,255,255,.62); padding: 60px 0 28px; font-size: 14px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 36px; margin-bottom: 40px; }
.site-footer h4 { color: #fff; font-size: 14px; text-transform: uppercase; letter-spacing: .08em; margin-bottom: 16px; font-weight: 600; }
.site-footer ul { list-style: none; }
.site-footer ul li { margin-bottom: 10px; }
.site-footer a { color: rgba(255,255,255,.62); }
.site-footer a:hover { color: var(--cyan-400); }
.footer-brand img { height: 30px; margin-bottom: 16px; }
.footer-brand p { max-width: 300px; line-height: 1.6; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.1); padding-top: 22px;
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; font-size: 13px;
}

/* Responsive -------------------------------------------------------------- */
@media (max-width: 860px) {
  .nav-toggle { display: block; }
  .nav-links {
    position: absolute; top: 68px; left: 0; right: 0; flex-direction: column; align-items: stretch;
    gap: 0; background: #fff; border-bottom: 1px solid var(--line); box-shadow: var(--shadow);
    padding: 8px 0; display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 13px 24px; font-size: 16px; }
  .nav-links a.login, .nav-links a.cta { margin: 8px 24px; text-align: center; }
  .contact-grid { grid-template-columns: 1fr; gap: 32px; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 28px; }
  .section { padding: 60px 0; }
  .hero { padding: 68px 0 60px; }
}
@media (max-width: 520px) {
  .footer-grid { grid-template-columns: 1fr; }
  .hero-actions .btn, .cta-band .btn { width: 100%; justify-content: center; }
}