/* ============================================================
   SERENITY RESEARCH LABS — Design System
   Luxury clinical aesthetic: Apple precision + Stripe warmth
   ============================================================ */

/* ---------- Custom Properties (Design Tokens) ---------- */
:root {
  /* Brand — deep navy anchor with refined blue accent */
  --sr-accent: #0a84ff;
  --sr-accent-hover: #0071e3;
  --sr-accent-subtle: rgba(10, 132, 255, 0.08);
  --sr-accent-glow: rgba(10, 132, 255, 0.15);

  /* Surfaces */
  --sr-black: #000000;
  --sr-dark: #0a0a0c;
  --sr-dark-elevated: #141416;
  --sr-dark-surface: #1c1c1e;
  --sr-white: #ffffff;
  --sr-offwhite: #f5f5f7;
  --sr-warm-gray: #fafafa;

  /* Text */
  --sr-text-primary: #1d1d1f;
  --sr-text-secondary: #6e6e73;
  --sr-text-tertiary: #86868b;
  --sr-text-on-dark: #f5f5f7;
  --sr-text-on-dark-secondary: rgba(245, 245, 247, 0.7);
  --sr-text-on-dark-tertiary: rgba(245, 245, 247, 0.45);

  /* Borders */
  --sr-border: rgba(0, 0, 0, 0.06);
  --sr-border-dark: rgba(255, 255, 255, 0.08);
  --sr-border-accent: rgba(10, 132, 255, 0.2);

  /* Shadows — Stripe-inspired multi-layer */
  --sr-shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --sr-shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06), 0 1px 3px rgba(0, 0, 0, 0.04);
  --sr-shadow-lg: 0 12px 40px rgba(50, 50, 93, 0.12), 0 4px 12px rgba(0, 0, 0, 0.06);
  --sr-shadow-xl: 0 24px 60px rgba(50, 50, 93, 0.15), 0 8px 24px rgba(0, 0, 0, 0.08);
  --sr-shadow-glow: 0 0 40px rgba(10, 132, 255, 0.12);

  /* Typography Scale */
  --sr-font-display: 'Plus Jakarta Sans', 'Inter', system-ui, -apple-system, sans-serif;
  --sr-font-body: 'Inter', system-ui, -apple-system, sans-serif;

  /* Spacing */
  --sr-section-py: clamp(5rem, 8vw, 8rem);
  --sr-content-max: 1120px;

  /* Transitions */
  --sr-ease: cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --sr-ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* ---------- Base ---------- */
body {
  font-family: var(--sr-font-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  color: var(--sr-text-primary);
  background: var(--sr-white);
}

/* ---------- Typography ---------- */
.sr-display {
  font-family: var(--sr-font-display);
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.06;
}

.sr-headline {
  font-family: var(--sr-font-display);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.25;
}

.sr-title {
  font-family: var(--sr-font-display);
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.2;
}

.sr-label {
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.sr-body {
  font-family: var(--sr-font-body);
  font-weight: 400;
  line-height: 1.65;
  color: var(--sr-text-secondary);
}

/* ---------- Navigation Glass ---------- */
.sr-nav-glass {
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--sr-border);
}

/* Shared nav polish. Desktop nav gets more breathing room; mobile remains tight. */
.sr-desktop-nav {
  gap: clamp(2.75rem, 5vw, 5.75rem) !important;
}

/* Age gate defaults hidden so verified users never see a page-switch flash. */
#age-gate:not(.active) {
  display: none !important;
}
#age-gate.active {
  display: flex !important;
}

/* ---------- Buttons ---------- */
.sr-btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.875rem 2rem;
  background: var(--sr-accent);
  color: var(--sr-white);
  font-family: var(--sr-font-body);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  border-radius: 980px;
  border: none;
  cursor: pointer;
  transition: background 0.3s var(--sr-ease), transform 0.3s var(--sr-ease), box-shadow 0.3s var(--sr-ease);
  text-decoration: none;
}

.sr-btn-primary:hover {
  background: var(--sr-accent-hover);
  transform: translateY(-1px);
  box-shadow: var(--sr-shadow-glow);
}

.sr-btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  color: var(--sr-accent);
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  transition: color 0.3s var(--sr-ease), gap 0.3s var(--sr-ease);
}

.sr-btn-secondary:hover {
  color: var(--sr-accent-hover);
  gap: 0.625rem;
}

/* ---------- Cards ---------- */
.sr-card {
  background: var(--sr-white);
  border-radius: 1rem;
  overflow: hidden;
  transition: transform 0.5s var(--sr-ease), box-shadow 0.5s var(--sr-ease);
}

.sr-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--sr-shadow-xl);
}

.sr-card-dark {
  background: var(--sr-dark-elevated);
  border: 1px solid var(--sr-border-dark);
  border-radius: 1.25rem;
  transition: border-color 0.4s var(--sr-ease), box-shadow 0.4s var(--sr-ease);
}

.sr-card-dark:hover {
  border-color: var(--sr-border-accent);
  box-shadow: var(--sr-shadow-glow);
}

/* ---------- Animations ---------- */
.sr-fade-up {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.9s var(--sr-ease), transform 0.9s var(--sr-ease);
}

.sr-fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

.sr-fade-up-delay-1 { transition-delay: 0.1s; }
.sr-fade-up-delay-2 { transition-delay: 0.2s; }
.sr-fade-up-delay-3 { transition-delay: 0.3s; }

/* ---------- Gradient Overlays ---------- */
.sr-gradient-dark-bottom {
  background: linear-gradient(to bottom, transparent 0%, var(--sr-dark) 100%);
}

.sr-hero-glow {
  position: absolute;
  bottom: -20%;
  left: 50%;
  transform: translateX(-50%);
  width: 60%;
  height: 50%;
  background: radial-gradient(ellipse, var(--sr-accent-glow) 0%, transparent 70%);
  pointer-events: none;
}

/* ---------- Mobile Menu ---------- */
#mobile-menu-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 70;
}
#mobile-menu-overlay.active { display: block; }

#mobile-menu {
  position: fixed;
  top: 0;
  right: -300px;
  width: 280px;
  height: 100%;
  background: var(--sr-white);
  z-index: 80;
  transition: right 0.3s var(--sr-ease);
  padding: 80px 32px 32px;
  box-shadow: -4px 0 20px rgba(0, 0, 0, 0.15);
}
#mobile-menu.active { right: 0; }
#mobile-menu a {
  display: block;
  padding: 16px 0;
  font-size: 1rem;
  font-weight: 500;
  color: var(--sr-text-primary);
  border-bottom: 1px solid var(--sr-offwhite);
  text-decoration: none;
  font-family: var(--sr-font-display);
}
#mobile-menu a:hover { color: var(--sr-accent); }
#mobile-menu .close-btn {
  position: absolute;
  top: 24px;
  right: 24px;
  background: none;
  border: none;
  cursor: pointer;
}

/* ---------- Scrollbar (subtle) ---------- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(0, 0, 0, 0.15); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: rgba(0, 0, 0, 0.25); }

/* ---------- Selection ---------- */
::selection {
  background: var(--sr-accent);
  color: var(--sr-white);
}

/* ---------- Utility: Section Padding ---------- */
.sr-section { padding: var(--sr-section-py) 1.5rem; }
.sr-container { max-width: var(--sr-content-max); margin: 0 auto; }


/* Global header fixes */
.sr-desktop-nav,
.hidden.md\:flex.items-center.gap-8,
.hidden.md\:flex.items-center.gap-10,
.hidden.md\:flex.gap-10.items-center {
  gap: clamp(2.75rem, 5vw, 5.75rem) !important;
}
.material-symbols-outlined[role="button"] { cursor: pointer; }
.material-symbols-outlined[role="button"]:focus-visible {
  outline: 2px solid var(--sr-accent);
  outline-offset: 4px;
  border-radius: 999px;
}