/* HELIX London — shared stylesheet for SEO sub-pages
   Brand tokens mirror Helix_London_Website.html */

:root {
  --bg: #02030a;
  --bg-card: #050714;
  --surface: #11142a;
  --surface-hi: #1a1f3d;
  --line: rgba(255,255,255,0.10);
  --line-strong: rgba(255,255,255,0.20);
  --violet: #8b6fff;
  --violet-hi: #a48fff;
  --cyan: #2af0ff;
  --cyan-hi: #6cf6ff;
  --text: #f4f6ff;
  --text-mute: #c2c9eb;
  --text-low: #9099bc;
  --grad: linear-gradient(135deg, #8b6fff 0%, #2af0ff 100%);
  --r-sm: 10px; --r-md: 14px; --r-lg: 20px; --r-xl: 28px;
  --max-w: 1200px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; overflow-x: hidden; }
body {
  font-family: 'Instrument Sans', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }
img { max-width: 100%; display: block; }
::selection { background: var(--violet); color: white; }

/* Typography */
.display, h1, h2, h3, h4 {
  font-family: 'Cabinet Grotesk', 'Instrument Sans', sans-serif;
  font-weight: 700; line-height: 1.05; letter-spacing: -0.025em;
  color: var(--text);
}
h1 { font-size: clamp(40px, 6vw, 76px); font-weight: 800; }
h2 { font-size: clamp(30px, 4.2vw, 52px); }
h3 { font-size: clamp(20px, 1.8vw, 24px); }
h4 { font-size: 16px; letter-spacing: 0.02em; }
p  { font-size: clamp(15px, 1vw, 17px); color: var(--text-mute); }
.lead { font-size: clamp(17px, 1.25vw, 20px); color: var(--text-mute); }
.eyebrow {
  font-size: 11px; font-weight: 600;
  letter-spacing: 0.22em; text-transform: uppercase;
  color: var(--cyan-hi); margin-bottom: 14px; display: inline-block;
}
.text-grad {
  background: var(--grad);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}

/* Layout */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 28px; }
section { padding: 96px 0; position: relative; }
@media (max-width: 640px) { section { padding: 64px 0; } }

/* Navbar */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  padding: 16px 0;
  background: rgba(2,3,10,0.55);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--line);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.logo { display: flex; align-items: center; gap: 12px; }
.logo-mark { width: 32px; height: 32px; }
.logo-text { font-family: 'Cabinet Grotesk', sans-serif; font-weight: 800; font-size: 18px; letter-spacing: -0.02em; }
.logo-text span { color: var(--text-low); font-weight: 500; }
.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a { font-size: 14px; color: var(--text-mute); transition: color 180ms var(--ease); }
.nav-links a:hover { color: var(--cyan-hi); }
@media (max-width: 860px) {
  .nav-links a:not(.btn) { display: none; }
}

/* Buttons */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 14px 24px; border-radius: 999px;
  font-size: 15px; font-weight: 600;
  transition: transform 220ms var(--ease), box-shadow 220ms var(--ease);
  will-change: transform;
}
.btn-primary {
  background: var(--grad);
  color: #02030a;
  box-shadow: 0 12px 28px -8px rgba(139,111,255,0.55), 0 0 0 1px rgba(255,255,255,0.08) inset;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 20px 40px -10px rgba(42,240,255,0.5); }
.btn-ghost {
  background: rgba(255,255,255,0.04);
  color: var(--text);
  border: 1px solid var(--line-strong);
}
.btn-ghost:hover { background: rgba(255,255,255,0.08); border-color: var(--violet); }

/* Page hero (sub-page version, shorter than home) */
.page-hero {
  padding: 180px 0 80px;
  position: relative;
  overflow: hidden;
}
.page-hero::before {
  content: ''; position: absolute; inset: 0;
  background:
    radial-gradient(ellipse 800px 400px at 15% 0%, rgba(139,111,255,0.18), transparent 60%),
    radial-gradient(ellipse 600px 400px at 85% 30%, rgba(42,240,255,0.12), transparent 60%);
  pointer-events: none;
}
.page-hero .container { position: relative; z-index: 1; }
.page-hero h1 { max-width: 900px; margin-bottom: 24px; }
.page-hero .lead { max-width: 720px; margin-bottom: 32px; }
.hero-cta-row { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 8px; }

/* Trust strip */
.trust {
  display: flex; flex-wrap: wrap; gap: 14px 22px;
  font-size: 13px; color: var(--text-low);
  padding: 14px 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line);
  margin-top: 28px;
}
.trust > span { display: inline-flex; align-items: center; gap: 6px; }
.trust strong { color: var(--text); font-weight: 600; }
.trust .star { color: var(--violet-hi); }

/* Card surfaces */
.card {
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 32px;
  transition: border-color 220ms var(--ease), transform 220ms var(--ease);
}
.card:hover { border-color: var(--line-strong); transform: translateY(-2px); }
.card h3 { margin-bottom: 12px; }
.card p { margin-bottom: 0; }

.grid { display: grid; gap: 20px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 920px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
}

/* Price card */
.price-card {
  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(255,255,255,0.01));
  border: 1px solid var(--line);
  border-radius: var(--r-xl);
  padding: 36px;
  display: flex; flex-direction: column;
  transition: border-color 220ms var(--ease), transform 220ms var(--ease);
}
.price-card:hover { border-color: var(--violet); transform: translateY(-3px); }
.price-card.featured { border-color: var(--violet); box-shadow: 0 30px 60px -20px rgba(139,111,255,0.35); }
.price-card .tier { font-size: 13px; font-weight: 600; letter-spacing: 0.15em; text-transform: uppercase; color: var(--cyan-hi); }
.price-card .price { font-family: 'Cabinet Grotesk', sans-serif; font-size: 56px; font-weight: 800; letter-spacing: -0.03em; margin: 6px 0 8px; }
.price-card .price small { font-size: 14px; color: var(--text-low); font-weight: 500; margin-left: 4px; }
.price-card .summary { color: var(--text-mute); margin-bottom: 22px; }
.price-card ul { list-style: none; margin: 0 0 28px; padding: 0; }
.price-card li { padding: 8px 0; padding-left: 22px; position: relative; font-size: 15px; color: var(--text-mute); border-bottom: 1px solid var(--line); }
.price-card li:last-child { border-bottom: 0; }
.price-card li::before {
  content: ''; position: absolute; left: 0; top: 16px;
  width: 12px; height: 12px;
  background: var(--grad); border-radius: 999px; opacity: 0.9;
}
.price-card .btn { margin-top: auto; align-self: flex-start; }

/* FAQ accordion (native <details>) */
.faq-list { max-width: 820px; margin: 0 auto; }
details.faq {
  border-bottom: 1px solid var(--line);
  padding: 4px 0;
}
details.faq summary {
  list-style: none;
  cursor: pointer;
  padding: 22px 0;
  font-family: 'Cabinet Grotesk', sans-serif;
  font-size: clamp(17px, 1.3vw, 21px); font-weight: 600; letter-spacing: -0.01em;
  color: var(--text);
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  transition: color 180ms var(--ease);
}
details.faq summary::-webkit-details-marker { display: none; }
details.faq summary::after {
  content: '+';
  flex: 0 0 28px;
  font-family: 'Cabinet Grotesk', sans-serif;
  font-size: 28px; font-weight: 400;
  color: var(--cyan-hi);
  transition: transform 220ms var(--ease);
}
details.faq[open] summary::after { transform: rotate(45deg); }
details.faq summary:hover { color: var(--cyan-hi); }
details.faq .answer {
  padding: 0 0 24px;
  color: var(--text-mute);
  font-size: 16px; line-height: 1.65;
  max-width: 720px;
}

/* Form */
.lead-form { max-width: 520px; }
.lead-form .field { margin-bottom: 18px; }
.lead-form label { display: block; font-size: 13px; font-weight: 600; color: var(--text-low); margin-bottom: 8px; letter-spacing: 0.05em; text-transform: uppercase; }
.lead-form input, .lead-form textarea {
  width: 100%; padding: 14px 16px;
  background: var(--bg-card);
  border: 1px solid var(--line-strong);
  border-radius: var(--r-md);
  color: var(--text); font-family: inherit; font-size: 16px;
  transition: border-color 220ms var(--ease), box-shadow 220ms var(--ease);
}
.lead-form input:focus, .lead-form textarea:focus { outline: none; border-color: var(--violet); box-shadow: 0 0 0 4px rgba(139,111,255,0.18); }
.lead-form textarea { min-height: 140px; resize: vertical; }
.lead-form .status { margin-top: 16px; font-size: 14px; color: var(--cyan-hi); min-height: 22px; }

/* Process steps */
.steps { counter-reset: step; display: grid; gap: 20px; }
.step { position: relative; padding: 28px 28px 28px 88px; background: var(--bg-card); border: 1px solid var(--line); border-radius: var(--r-lg); }
.step::before {
  counter-increment: step;
  content: counter(step);
  position: absolute; left: 24px; top: 24px;
  width: 48px; height: 48px;
  font-family: 'Cabinet Grotesk', sans-serif; font-size: 22px; font-weight: 800;
  background: var(--grad); color: #02030a;
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
}
.step h3 { margin-bottom: 8px; }
.step .meta { font-size: 13px; color: var(--cyan-hi); margin-top: 8px; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; }

/* Final CTA band */
.final-cta {
  text-align: center;
  background:
    radial-gradient(ellipse 600px 300px at 50% 0%, rgba(139,111,255,0.2), transparent 70%),
    var(--bg);
  border-top: 1px solid var(--line);
}
.final-cta h2 { margin-bottom: 14px; }
.final-cta p { max-width: 580px; margin: 0 auto 28px; }

/* Footer */
footer {
  border-top: 1px solid var(--line);
  padding: 64px 0 40px;
  background: linear-gradient(180deg, transparent, rgba(0,0,0,0.4));
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 48px; }
@media (max-width: 820px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
.footer-brand p { margin-top: 16px; max-width: 320px; font-size: 14px; }
.footer-col h4 { font-size: 12px; letter-spacing: 0.18em; text-transform: uppercase; color: var(--text-low); margin-bottom: 18px; font-weight: 600; }
.footer-col a { display: block; padding: 6px 0; font-size: 14px; color: var(--text-mute); transition: color 180ms var(--ease); }
.footer-col a:hover { color: var(--cyan-hi); }
.footer-bottom { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; padding-top: 28px; border-top: 1px solid var(--line); font-size: 13px; color: var(--text-low); }
.footer-areas { padding: 18px 0; border-top: 1px solid var(--line); font-size: 13px; color: var(--text-low); }
.footer-areas a { color: var(--text-mute); }
.footer-areas a:hover { color: var(--cyan-hi); }

/* Utility */
.pad-top-sm { padding-top: 48px; }
.center { text-align: center; }
.mt-lg { margin-top: 40px; }
.mb-lg { margin-bottom: 40px; }
.muted { color: var(--text-low); }
.divider { height: 1px; background: var(--line); margin: 48px 0; }
.tag { display: inline-block; padding: 4px 12px; font-size: 12px; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; color: var(--cyan-hi); background: rgba(42,240,255,0.08); border: 1px solid rgba(42,240,255,0.25); border-radius: 999px; }