/* =========================================================================
   SD FRAMEWORKS — DESIGN SYSTEM
   Derived from the approved brand mark (white_horizontal.png / white_only_logo.png):
     - Clean white / soft-neutral background
     - Electric blue accent "S" (#2F6BFF -> #4FC3FF cyan highlight)
     - Brushed silver/chrome "D" + charcoal wordmark
     - Bold extruded sans-serif typography, wide letter-spacing labels
     - Premium, minimal, image-forward layout
   ========================================================================= */

:root {
  /* Backgrounds */
  --bg-0: #ffffff;
  --bg-1: #f7f8fb;
  --bg-2: #f0f2f6;
  --bg-3: #e8eaf0;
  --surface: #ffffff;
  --surface-2: #f7f8fb;
  --surface-glass: rgba(255, 255, 255, 0.72);
  --border: #e6e8ee;
  --border-bright: #d7dbe3;

  /* Brand — electric blue (from S monogram) */
  --blue-900: #0b2a73;
  --blue-700: #1a44c4;
  --blue-500: #2f6bff;
  --blue-400: #4f8bff;
  --blue-300: #1f5fe0;
  --blue-glow: rgba(47, 107, 255, 0.22);
  --blue-glow-soft: rgba(47, 107, 255, 0.10);

  /* Brand — metallic silver (from D monogram / wordmark) */
  --silver-100: #f3f5f7;
  --silver-300: #cdd2d9;
  --silver-500: #9aa2ac;
  --silver-700: #6b7280;
  --steel-900: #363c46;

  /* Text */
  --text-0: #12151c;
  --text-1: #3d4351;
  --text-2: #6b7280;
  --text-3: #9aa1ac;

  /* Effects */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-pill: 999px;
  --shadow-soft: 0 20px 60px rgba(16, 24, 40, 0.10);
  --shadow-card: 0 12px 30px rgba(16, 24, 40, 0.08);
  --shadow-glow: 0 0 60px var(--blue-glow-soft);
  --ease-premium: cubic-bezier(0.16, 1, 0.3, 1);

  --font-display: "Sora", "Inter", system-ui, sans-serif;
  --font-body: "Inter", system-ui, sans-serif;

  --container-w: 1280px;
}

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

html {
  scroll-behavior: smooth;
  background: var(--bg-0);
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(1100px 620px at 82% -8%, rgba(47, 107, 255, 0.07), transparent 60%),
    radial-gradient(900px 520px at -10% 20%, rgba(79, 195, 255, 0.05), transparent 55%),
    linear-gradient(180deg, var(--bg-0) 0%, var(--bg-1) 45%, var(--bg-0) 100%);
  color: var(--text-1);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* Subtle grid overlay for premium depth */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.5;
  background-image:
    linear-gradient(rgba(16, 24, 40, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(16, 24, 40, 0.025) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 40%, transparent 90%);
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
ul { list-style: none; margin: 0; padding: 0; }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  color: var(--text-0);
  margin: 0;
  line-height: 1.1;
  letter-spacing: -0.01em;
  font-weight: 700;
}

p { margin: 0; }

::selection { background: var(--blue-500); color: #fff; }

/* Scrollbar */
::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: var(--bg-1); }
::-webkit-scrollbar-thumb { background: var(--border-bright); border-radius: 10px; }
::-webkit-scrollbar-thumb:hover { background: var(--silver-500); }

/* ---------------- Layout utilities ---------------- */
.container {
  width: 100%;
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px;
}

.section { position: relative; padding: 120px 0; z-index: 1; }
.section-tight { padding: 80px 0; }

@media (max-width: 860px) {
  .section { padding: 80px 0; }
  .section-tight { padding: 56px 0; }
}

.label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--blue-300);
}

.label::before {
  content: "";
  width: 22px;
  height: 1px;
  background: linear-gradient(90deg, var(--blue-300), transparent);
}

.eyebrow-center { justify-content: center; }
.eyebrow-center::before { display: none; }

.section-head { max-width: 720px; margin-bottom: 56px; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }

.h-xl { font-size: clamp(2.6rem, 5.4vw, 4.6rem); }
.h-lg { font-size: clamp(2.1rem, 3.6vw, 3.2rem); }
.h-md { font-size: clamp(1.5rem, 2.4vw, 2rem); }

.text-muted { color: var(--text-2); }
.text-lead { font-size: 1.1rem; color: var(--text-1); line-height: 1.7; }

.gradient-text {
  background: linear-gradient(120deg, var(--text-0) 10%, var(--blue-500) 55%, var(--silver-700) 90%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ---------------- Buttons ---------------- */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 15px 30px;
  border-radius: var(--radius-pill);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border: 1px solid transparent;
  transition: transform 0.35s var(--ease-premium), box-shadow 0.35s var(--ease-premium), border-color 0.3s ease, background 0.3s ease;
  white-space: nowrap;
}

.btn:active { transform: translateY(1px) scale(0.99); }

.btn-primary {
  background: linear-gradient(135deg, var(--blue-400), var(--blue-700));
  color: #fff;
  box-shadow: 0 10px 30px rgba(47, 107, 255, 0.28), inset 0 1px 0 rgba(255, 255, 255, 0.2);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 16px 40px rgba(47, 107, 255, 0.38), inset 0 1px 0 rgba(255, 255, 255, 0.25); }

.btn-outline {
  background: #fff;
  color: var(--text-0);
  border-color: var(--border-bright);
}
.btn-outline:hover { border-color: var(--blue-300); color: var(--blue-500); transform: translateY(-2px); background: var(--blue-glow-soft); }

.btn-sm { padding: 10px 20px; font-size: 11px; }
.btn-block { width: 100%; }

.btn-ghost-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--blue-500);
  text-transform: uppercase;
  transition: gap 0.25s ease, color 0.25s ease;
}
.btn-ghost-link:hover { gap: 12px; color: var(--blue-700); }
.btn-ghost-link .arrow { transition: transform 0.25s ease; }
.btn-ghost-link:hover .arrow { transform: translateX(3px); }

/* ---------------- Glass / metallic surfaces ---------------- */
.glass-panel {
  background: var(--surface-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.metal-edge {
  border-image: linear-gradient(135deg, rgba(16,24,40,.12), rgba(16,24,40,0) 40%) 1;
}

/* ---------------- Scroll reveal ---------------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.9s var(--ease-premium), transform 0.9s var(--ease-premium);
}
[data-reveal].is-visible { opacity: 1; transform: translateY(0); }
[data-reveal="fade"] { transform: none; }
[data-reveal-delay="1"] { transition-delay: 0.08s; }
[data-reveal-delay="2"] { transition-delay: 0.16s; }
[data-reveal-delay="3"] { transition-delay: 0.24s; }
[data-reveal-delay="4"] { transition-delay: 0.32s; }

@media (prefers-reduced-motion: reduce) {
  [data-reveal] { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

.no-overflow-x { overflow-x: hidden; }

.divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-bright), transparent);
  border: 0;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border-radius: var(--radius-pill);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  background: var(--blue-glow-soft);
  color: var(--blue-500);
  border: 1px solid rgba(47, 107, 255, 0.2);
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--blue-500);
  color: #fff;
  padding: 10px 16px;
  z-index: 999;
}
.skip-link:focus { left: 16px; top: 16px; }