/* =============================================
   ST4AI.COM — Shared Stylesheet
   White background, #1E56C8 blue, #0A7A62 green
   ============================================= */

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

:root {
  --bg: #FFFFFF;
  --surface: #F7F9FF;
  --surface-2: #EDF0F6;
  --border: rgba(30, 86, 200, 0.14);
  --text: #0B1829;
  --muted: #6b7280;
  --accent: #1E56C8;
  --accent-warm: #0A7A62;
  --accent-glow: rgba(30, 86, 200, 0.08);
  --accent-warm-glow: rgba(10, 122, 98, 0.08);
  --radius: 8px;
  --max-w: 820px;
}

html { scroll-behavior: smooth; }
body { background: var(--bg); color: var(--text); font-family: 'Inter', system-ui, -apple-system, sans-serif; font-size: 16px; line-height: 1.6; min-height: 100vh; }

/* ----- TYPE ----- */
h1 { font-size: clamp(2rem, 5vw, 3.4rem); line-height: 1.1; font-weight: 700; letter-spacing: -0.02em; color: var(--text); }
h2 { font-size: clamp(1.3rem, 3vw, 1.9rem); font-weight: 600; line-height: 1.2; color: var(--text); }
h3 { font-size: 1rem; font-weight: 600; color: var(--text); }
p  { color: var(--muted); }
em { font-style: italic; color: var(--text); }

/* ----- NAV ----- */
nav { position: fixed; top: 0; width: 100%; z-index: 100; background: rgba(255,255,255,0.94); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border-bottom: 1px solid rgba(11,24,41,0.07); }
.nav-inner { max-width: 1100px; margin: 0 auto; padding: 0 24px; height: 52px; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.nav-logo { font-weight: 800; font-size: 1rem; color: var(--text); text-decoration: none; letter-spacing: -0.5px; flex-shrink: 0; }
.nav-logo span { color: var(--accent); }
.nav-links { display: flex; gap: 4px; list-style: none; flex-wrap: wrap; }
.nav-links a { color: var(--muted); text-decoration: none; font-size: 0.82rem; padding: 5px 10px; border-radius: var(--radius); transition: color 0.15s; white-space: nowrap; }
.nav-links a:hover { color: var(--text); }
.nav-links a.active { color: var(--text); font-weight: 600; }
.nav-cta { background: var(--accent) !important; color: #FFFFFF !important; font-weight: 700 !important; border-radius: 20px !important; padding: 6px 16px !important; transition: background 0.15s !important; }
.nav-cta:hover { background: #1645a8 !important; color: #FFFFFF !important; }

/* ----- CANVAS (hidden) ----- */
#network-canvas { display: none; }

/* ----- LAYOUT ----- */
.page { position: relative; z-index: 1; padding-top: 52px; }

/* ----- HERO ----- */
.hero { max-width: var(--max-w); margin: 0 auto; padding: 80px 24px 52px; text-align: center; }
.byline { display: inline-flex; align-items: center; gap: 8px; font-size: 0.75rem; color: var(--muted); margin-bottom: 28px; letter-spacing: 0.1em; text-transform: uppercase; }
.byline-dot { width: 4px; height: 4px; border-radius: 50%; background: var(--accent); flex-shrink: 0; }
.hero h1 { margin-bottom: 20px; }
.hero .subtitle { font-size: clamp(1rem, 2vw, 1.15rem); max-width: 580px; margin: 0 auto 36px; line-height: 1.75; }

/* ----- BADGE ----- */
.discount-badge { display: inline-flex; align-items: center; gap: 6px; background: rgba(10,122,98,0.08); border: 1px solid rgba(10,122,98,0.22); color: var(--accent-warm); font-size: 0.78rem; font-weight: 600; padding: 6px 14px; border-radius: 100px; margin-bottom: 32px; letter-spacing: 0.02em; }

/* ----- FORM ----- */
.form-section { max-width: 480px; margin: 0 auto 28px; }
.form-label { display: block; font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.1em; color: var(--muted); margin-bottom: 12px; }
.form-row { display: flex; gap: 8px; }
.form-input { flex: 1; background: var(--surface); border: 1px solid var(--border); color: var(--text); padding: 12px 16px; border-radius: var(--radius); font-size: 0.95rem; font-family: inherit; outline: none; transition: border-color 0.2s, box-shadow 0.2s; }
.form-input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-glow); }
.form-input::placeholder { color: var(--muted); }
.form-note { font-size: 0.76rem; color: var(--muted); margin-top: 10px; opacity: 0.65; }
.thank-you { display: none; background: rgba(10,122,98,0.06); border: 1px solid rgba(10,122,98,0.2); border-radius: var(--radius); padding: 24px 20px; text-align: center; }
.thank-you h3 { color: var(--accent-warm); margin-bottom: 8px; font-size: 1.1rem; }
.thank-you p { font-size: 0.9rem; }

/* ----- BUTTONS ----- */
.btn { background: var(--accent); color: #FFFFFF; font-weight: 700; padding: 12px 20px; border: none; border-radius: var(--radius); cursor: pointer; font-size: 0.9rem; font-family: inherit; white-space: nowrap; transition: background 0.15s, transform 0.1s; display: inline-block; text-decoration: none; text-align: center; }
.btn:hover { background: #1645a8; }
.btn:active { transform: scale(0.98); }
.btn-warm { background: var(--accent-warm); }
.btn-warm:hover { background: #086650; }
.btn-outline { background: transparent; border: 1.5px solid var(--accent); color: var(--accent); }
.btn-outline:hover { background: var(--accent-glow); }
.btn-lg { padding: 16px 32px; font-size: 1rem; }

/* ----- FEATURES ----- */
.features { max-width: 680px; margin: 0 auto 56px; display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 14px; padding: 0 24px; }
.feature-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px 18px; }
.feature-card .icon { font-size: 1.4rem; margin-bottom: 10px; }
.feature-card h3 { color: var(--text); margin-bottom: 6px; font-size: 0.92rem; }
.feature-card p { font-size: 0.83rem; line-height: 1.55; }

/* ----- SECTION ----- */
.section { max-width: var(--max-w); margin: 0 auto; padding: 0 24px 56px; }
.section h2 { margin-bottom: 16px; }
.section p { margin-bottom: 12px; }

/* ----- TIERS (preorder) ----- */
.tiers { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 32px 0; }
.tier { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px 14px; position: relative; }
.tier.featured { border-color: var(--accent); border-width: 2px; background: rgba(30,86,200,0.04); }
.tier-badge { position: absolute; top: -11px; left: 50%; transform: translateX(-50%); background: var(--accent); color: #FFFFFF; font-size: 0.65rem; font-weight: 700; padding: 3px 10px; border-radius: 100px; white-space: nowrap; letter-spacing: 0.05em; text-transform: uppercase; }
.tier-name { font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); margin-bottom: 6px; }
.tier-price { font-size: 1.5rem; font-weight: 700; color: var(--text); line-height: 1; margin-bottom: 4px; }
.tier-price span { font-size: 0.85rem; font-weight: 400; color: var(--muted); }
.tier-orig { font-size: 0.72rem; color: var(--muted); text-decoration: line-through; margin-bottom: 12px; }
.tier ul { list-style: none; margin: 0 0 16px; }
.tier ul li { font-size: 0.74rem; color: var(--muted); padding: 4px 0; border-bottom: 1px solid var(--border); display: flex; align-items: center; gap: 6px; }
.tier ul li::before { content: '✓'; color: var(--accent-warm); font-weight: 700; flex-shrink: 0; }
.tier .btn { width: 100%; padding: 10px 12px; font-size: 0.82rem; }

@media (max-width: 700px) {
  .tiers { grid-template-columns: 1fr; }
}

/* ----- DIVIDER ----- */
.divider { max-width: var(--max-w); margin: 0 auto 40px; border: none; border-top: 1px solid var(--border); }

/* ----- CROSS-LINKS ----- */
.cross-links { max-width: var(--max-w); margin: 0 auto; padding: 0 24px 48px; }
.cross-links-label { text-align: center; font-size: 0.73rem; text-transform: uppercase; letter-spacing: 0.1em; color: var(--muted); margin-bottom: 16px; }
.cross-link-grid { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; }
.cross-link { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px 18px; text-decoration: none; transition: border-color 0.2s, background 0.2s; display: flex; flex-direction: column; gap: 3px; min-width: 170px; max-width: 210px; }
.cross-link:hover { border-color: var(--accent); background: var(--accent-glow); }
.cl-label { font-size: 0.72rem; color: var(--muted); text-transform: uppercase; letter-spacing: 0.08em; }
.cl-cta { font-size: 0.88rem; font-weight: 600; color: var(--accent); }

/* ----- FOOTER ----- */
footer { border-top: 1px solid var(--border); padding: 28px 24px; text-align: center; font-size: 0.78rem; color: var(--muted); }
footer a { color: var(--accent); text-decoration: none; }
footer a:hover { color: var(--text); }

/* ----- MOBILE ----- */
@media (max-width: 640px) {
  .nav-links li:nth-child(n+3) { display: none; }
  .form-row { flex-direction: column; }
  .btn { width: 100%; }
  .features { grid-template-columns: 1fr 1fr; }
  .tiers { grid-template-columns: 1fr; }
  .cross-link { min-width: 140px; }
}
@media (max-width: 400px) {
  .features { grid-template-columns: 1fr; }
}