/* Minimal utility-ish CSS tailored for GitHub Pages (no Tailwind build needed) */
:root {
  --bg: #0b1220;
  --ink: #0e1726;
  --text: #0f172a;
  --muted: #475569;
  --brand: #111827;
  --primary: #111827;
  --accent: #2563eb;
  --surface: #ffffff;
  --border: #e5e7eb;
  --accent-ink: #ffffff;
  --shadow: 0 6px 24px rgba(2, 6, 23, .08);
}
* { box-sizing: border-box }
body { margin: 0; font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif; line-height: 1.6; color: var(--text); }
h1 { font-size: 2.25rem; line-height: 1.15; margin: .3em 0 }
h2 { font-size: 1.75rem; line-height: 1.2; margin: 1.2em 0 .6em }
h3 { font-size: 1.25rem; line-height: 1.3; margin: 1.1em 0 .5em }
.lead { font-size: 1.125rem; color: var(--muted); max-width: 48rem }
.container { max-width: 1160px; margin: 0 auto; padding: 0 1rem }
.nav { position: sticky; top: 0; backdrop-filter: saturate(180%) blur(10px); background: rgba(255, 255, 255, .88); border-bottom: 1px solid #e5e7eb; z-index: 20; transition:box-shadow .2s ease, background-color .2s ease; }
.nav.elevated{ box-shadow:0 8px 28px rgba(2,6,23,.10); background:rgba(255,255,255,.92); }
.menu-open .nav{ box-shadow:0 10px 32px rgba(2,6,23,.14); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; padding: .8rem 0 }
.brand { font-weight: 600; text-decoration: none; color: var(--text); display: flex; align-items: center; }
.nav-logo { height: 32px; width: auto; margin-right: 0.5rem;}
.logo-abbr {
  font-family: inherit;
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--text);
  white-space: nowrap;
}

@media (max-width: 768px) {
  .logo-abbr {
    font-size: 1rem;
  }
}
.nav-links a { margin-left: 1rem; color: #374151; text-decoration: none }
.nav-links a:hover { color: #111 }
.hero { background: #0e1726; color: #e5e7eb; padding: 5rem 0; position: relative; overflow: hidden; }
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(600px 300px at 15% 20%, rgba(255, 255, 255, .08), transparent),
    radial-gradient(600px 300px at 85% 80%, rgba(255, 255, 255, .06), transparent),
    linear-gradient(45deg, #0b1220 0%, #111827 100%);
  background-size: 120% 120%;
  animation: gradient-flow 18s ease-in-out infinite alternate;
  z-index: -1;
}
@keyframes gradient-flow {
  0% { background-position: 0% 40%, 100% 60%, 0% 50% }
  100% { background-position: 10% 45%, 90% 55%, 100% 50% }
}
.xl { font-size: 2.8rem; margin: 0 }
.hero-content { max-width: 640px; margin: 0 auto; text-align: center; }
.hero .cta-row { justify-content: center; }
.trust-bullets { display: flex; gap: 1rem; margin-top: 1.5rem; flex-wrap: wrap; font-size: 0.9rem; color: #94a3b8; }
.trust-bullets span::before { content: '✓'; margin-right: 0.5rem; color: #34d399; }
.grid-2 { display: grid; grid-template-columns: 1.2fr 1fr; gap: 2rem }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem }
@media (max-width: 900px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr }
}
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 16px; padding: 1rem; color: #0f172a; box-shadow: var(--shadow) }
.card-title { font-weight: 600; margin-bottom: .3rem }
.card-icon { height: 40px; margin-bottom: 1rem; }
.card-image-top { width: 100%; height: 120px; object-fit: cover; border-radius: 16px 16px 0 0; margin: -1rem -1rem 1rem -1rem; }
.section { padding: 3.5rem 0 }
@media (max-width: 900px) { .section { padding: 2.5rem 0 } }
.cta-row { display: flex; gap: .75rem; margin-top: 1.25rem; flex-wrap: wrap }
.btn { display: inline-flex; align-items: center; justify-content: center; padding: .75rem 1rem; border-radius: 12px; border: 1px solid #e5e7eb; text-decoration: none; color: #111; background: #fff; min-height: 44px; transition: background-color .2s, box-shadow .2s }
.btn:hover { background: #f8fafc; box-shadow: 0 4px 14px rgba(2, 6, 23, .06) }
.btn:active{ transform:translateY(1px); }
.btn:focus-visible { outline: 3px solid rgba(37, 99, 235, .35); outline-offset: 2px }
.btn-primary { background: var(--accent); border-color: var(--accent); color: #fff }
.btn-primary:hover { filter: brightness(.96); box-shadow:0 6px 20px rgba(37,99,235,.22); }
.btn-buy-rdt { background-color: #f59e0b; border-color: #f59e0b; color: #fff; }
.btn-buy-rdt:hover { background-color: #d97706; border-color: #d97706; box-shadow:0 6px 20px rgba(245,158,11,.22); }
.muted { color: #475569 }
.notice { background: #fff7ed; border-top: 1px solid #fed7aa; border-bottom: 1px solid #fed7aa; padding: 1.5rem 0 }
/* Unified minimal footer for all devices */
.footer{
  border-top:1px solid #e5e7eb;
  padding:1rem 0 calc(1rem + env(safe-area-inset-bottom));
  text-align:center;
}
.footer-inner{
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:.5rem;
}
.footer-inner small{
  color:#64748b;
  font-size:.875rem;
}
.social-links a{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:44px;
  padding:0 .75rem;
  border-radius:8px;
  text-decoration:none;
  color:#4b5563;
  font-size:.9rem;
  font-weight:500;
}
.social-links a:hover{
  background:#f8fafc;
  color:#111827;
}
.form-grid { display: grid; grid-template-columns: 2fr 1fr; gap: .5rem; margin-top: 1rem }
input[type="email"] { height: 48px; border: 1px solid #e5e7eb; border-radius: 12px; padding: 0 12px; font: inherit }
.tiny { font-size: .8rem; color: #64748b }
.narrow { max-width: 640px }
.lang-toggle { margin-left: 1rem; color: #9ca3af; }
.lang-toggle a { color: #4b5563; }
.lang-toggle a:hover { color: #111827; opacity: 1; }
.lang-toggle span { font-weight: 600; }
.lang-toggle a { opacity: .9 }
.footer-links a, .social-links a { margin-left: 1rem; color: #4b5563; text-decoration: none; }
.footer-links a:hover, .social-links a:hover { color: #111827; }
.social-links { text-align: right; }
.rdt-utility .card { text-align: center; }
.rdt-utility .card p { color: var(--muted) }
.footnote { font-size: .875rem; color: #64748b }
.kv-list { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem }
@media (max-width: 900px) { .kv-list { grid-template-columns: 1fr } }
.kv-item { background: var(--surface); border: 1px solid var(--border); border-radius: 16px; padding: 1rem; box-shadow: var(--shadow) }
.kv-item h3 { margin: .25rem 0 .25rem }
.note { background: #f8fafc; border: 1px solid var(--border); border-radius: 12px; padding: 1rem }
.disclosure { background: #fff7ed; border: 1px solid #fed7aa; color: #7c2d12; border-radius: 12px; padding: 1rem }
a { color: var(--accent) }
a:hover { text-decoration: underline }
a:focus-visible { outline: 3px solid rgba(37, 99, 235, .35); outline-offset: 2px }
img { max-width: 100%; height: auto }
img[loading="lazy"] { filter: saturate(1) }

/* Responsive nav */
.hamburger{
  display:none;
  background:transparent;border:0;cursor:pointer;padding:.5rem;line-height:0;
}
.hamburger:focus-visible{outline:3px solid rgba(37,99,235,.35);outline-offset:2px}
.hamburger-box{display:inline-block;width:28px;height:20px;position:relative}
.hamburger-inner,
.hamburger-inner::before,
.hamburger-inner::after{
  width:28px;height:2px;background:#111;border-radius:2px;position:absolute;left:0;transition:transform .2s,opacity .2s,top .2s,bottom .2s
}
.hamburger-inner{top:9px}
.hamburger-inner::before{content:"";top:-8px}
.hamburger-inner::after{content:"";bottom:-8px}

/* active (X) state */
.menu-open .hamburger-inner{transform:rotate(45deg)}
.menu-open .hamburger-inner::before{top:0;transform:rotate(90deg)}
.menu-open .hamburger-inner::after{bottom:0;opacity:0}

/* desktop vs mobile visibility */
.desktop-nav{display:flex;align-items:center;gap:1rem}
@media (max-width:768px){
  .desktop-nav{display:none}
  .hamburger{display:inline-flex}
}

/* keep header height stable */
.nav .nav-inner{min-height:56px}

/* prevent body scroll when menu open (safari friendly) */
.menu-open body{overflow:hidden}

/* MOBILE DROPDOWN MENU (working version) */
.mobile-menu{
  position:fixed; inset:56px 0 auto 0;  /* below header */
  background:#ffffff; border-top:1px solid #e5e7eb; z-index:19;
  transform:translateY(-8px); opacity:0; pointer-events:none;
  transition:transform .2s ease, opacity .2s ease;
  max-height:calc(100vh - 56px); overflow:auto; -webkit-overflow-scrolling:touch;
}
.menu-open .mobile-menu{transform:translateY(0); opacity:1; pointer-events:auto}
.mobile-menu-inner{display:flex;flex-direction:column;gap:.25rem;padding:1rem}
.mobile-link{
  display:block;padding:.9rem 1rem;min-height:44px;border-radius:12px;
  background:#fff;border:1px solid #e5e7eb;color:#111;text-decoration:none;font-weight:600;
}
.mobile-link:hover{background:#f8fafc}
.mobile-lang{margin-top:.25rem;display:grid;grid-template-columns:1fr 1fr;gap:.25rem}

/* Visually hidden utility (for <h2 class="sr-only">) */
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,1,1);white-space:nowrap;border:0}

/* Nav links hover/active (desktop only) */
@media (min-width: 769px){
  .desktop-nav a{
    position:relative; padding:.25rem 0; transition:color .15s ease;
  }
  .desktop-nav a:hover{ color:#0b1220; }
}

/* Buttons: subtle press/hover */
.btn:hover{ background:#f8fafc; box-shadow:0 4px 14px rgba(2,6,23,.06); }
.btn:active{ transform:translateY(1px); }
.btn-primary:hover{ filter:brightness(.96); box-shadow:0 6px 20px rgba(37,99,235,.22); }
.btn-buy-rdt:hover{ box-shadow:0 6px 20px rgba(245,158,11,.22); }

/* Cards: lift on hover (desktop) */
@media (min-width: 769px){
  .card{ transition:box-shadow .2s ease, transform .2s ease; }
  .card:hover{ box-shadow:0 10px 30px rgba(2,6,23,.12); transform:translateY(-2px); }
}

/* Reduce motion respect */
@media (prefers-reduced-motion: reduce){
  .nav{ transition:none; }
  .card, .desktop-nav a::after, .btn, .btn-primary, .btn-buy-rdt{ transition:none; }
  .mobile-menu{transition:none}
}

@media (prefers-color-scheme: dark){
  :root{
    --surface:#0b1220;
    --ink:#e5e7eb;
    --text:#e5e7eb;
    --muted:#94a3b8;
    --border:#1f2937;
  }

  body{ background:#0a0f1c; color:var(--text); }

  /* Nav */
  .nav{ background:rgba(11,18,32,.85); border-bottom:1px solid #1f2937; }
  .desktop-nav a{ color:#cbd5e1; }
  .desktop-nav a:hover{ color:#ffffff; }
  .hamburger-inner, .hamburger-inner::before, .hamburger-inner::after{ background:#e5e7eb; }

  /* Hero */
  .hero{ color:#e5e7eb; background:linear-gradient(180deg,#0b1220 0%,#0e1726 100%); }
  .hero::before{
    background:
      radial-gradient(600px 300px at 15% 20%, rgba(255,255,255,.10), transparent),
      radial-gradient(600px 300px at 85% 80%, rgba(255,255,255,.08), transparent),
      linear-gradient(45deg, #0b1220 0%, #0e1726 100%);
  }

  /* Cards / sections */
  .card{ background:#0e1726; border-color:#1f2937; color:#e5e7eb; }
  .card p{ color:var(--muted); }
  .spec{ background:#0f172a; border-color:#1f2937; }
  .notice{ background:#0f172a; border-top-color:#1f2937; border-bottom-color:#1f2937; }

  /* Buttons */
  .btn{ background:#0f172a; border-color:#1f2937; color:#e5e7eb; }
  .btn:hover{ background:#111827; box-shadow:0 4px 14px rgba(2,6,23,.35); }
  .btn-ghost{ color:#e5e7eb; border-color:#334155; }
  .btn-primary{ color:#fff; }
  .btn-buy-rdt{ color:#fff; }

  /* Links */
  a{ color:#7aa2ff; }
  a:hover{ color:#a9c1ff; text-decoration:underline; }

  .mobile-menu{ background:#0b1220; border-top-color:#1f2937;}
  .mobile-link{ background:#0f172a; border-color:#1f2937; color:#e5e7eb; }
  .mobile-link:hover{ background:#111827; }

  /* Footer */
  .footer{ border-top:1px solid #374151; }
  .footer-inner small{
    color:#9ca3af;
  }
  .footer-links a, .social-links a{ color:#94a3b8; }
  .footer-links a:hover, .social-links a:hover{ color:#e5e7eb; }

  /* Bullets / footnotes */
  .footnote{ color:#94a3b8; }
}