/* ==========================================================================
   FairTech Design System
   Opt-in visual foundation (tokens, glass, 3D, motion, type, buttons, cards).
   Namespaced with `--ds-` / `ds-` so nothing here touches existing markup
   or collides with Bootstrap's `.btn-*` / `.card` utility classes.
   Adding this file changes nothing until a page opts into `.ds-*` classes.
   ========================================================================== */

:root {
  /* Background */
  --ds-bg-base: #060b16;
  --ds-bg-raised: #0a1120;
  --ds-bg-deep: #030712;

  /* Surface */
  --ds-surface-1: #0d1526;
  --ds-surface-2: #121b30;
  --ds-surface-glass: rgba(18, 27, 48, 0.55);
  --ds-surface-glass-strong: rgba(18, 27, 48, 0.78);

  /* Text */
  --ds-text-primary: #f3f6fc;
  --ds-text-secondary: #aab4c8;
  --ds-text-muted: #7c869c;
  --ds-text-inverse: #0a1120;

  /* Border */
  --ds-border-subtle: rgba(255, 255, 255, 0.08);
  --ds-border-strong: rgba(255, 255, 255, 0.16);
  --ds-border-accent: rgba(56, 132, 255, 0.4);

  /* Accent */
  --ds-accent: #3d8bff;
  --ds-accent-strong: #0066ff;
  --ds-accent-soft: rgba(61, 139, 255, 0.16);
  --ds-accent-glow: rgba(61, 139, 255, 0.45);
  --ds-success: #22c58b;
  --ds-danger: #ff5470;

  /* Shadow */
  --ds-shadow-sm: 0 2px 10px rgba(2, 6, 16, 0.35);
  --ds-shadow-md: 0 12px 32px rgba(2, 6, 16, 0.45);
  --ds-shadow-lg: 0 24px 60px rgba(2, 6, 16, 0.55);
  --ds-shadow-glow: 0 0 0 1px var(--ds-border-accent), 0 8px 30px var(--ds-accent-glow);

  /* Radius */
  --ds-radius-sm: 8px;
  --ds-radius-md: 14px;
  --ds-radius-lg: 22px;
  --ds-radius-xl: 30px;
  --ds-radius-pill: 999px;

  /* Spacing */
  --ds-space-3xs: 2px;
  --ds-space-2xs: 4px;
  --ds-space-xs: 8px;
  --ds-space-sm: 12px;
  --ds-space-md: 20px;
  --ds-space-lg: 32px;
  --ds-space-xl: 48px;
  --ds-space-2xl: 72px;

  /* Typography scale */
  --ds-font-family: "Poppins", sans-serif;
  --ds-font-size-display: clamp(2.75rem, 2.1rem + 2.6vw, 4.5rem);
  --ds-font-size-h1: clamp(2.25rem, 1.85rem + 1.6vw, 3.25rem);
  --ds-font-size-h2: clamp(1.75rem, 1.5rem + 1vw, 2.5rem);
  --ds-font-size-h3: clamp(1.35rem, 1.2rem + 0.6vw, 1.75rem);
  --ds-font-size-body: 1rem;
  --ds-font-size-small: 0.875rem;
  --ds-font-size-caption: 0.75rem;
  --ds-line-height-tight: 1.15;
  --ds-line-height-normal: 1.5;

  /* Motion */
  --ds-duration-fast: 160ms;
  --ds-duration-base: 280ms;
  --ds-duration-slow: 520ms;
  --ds-duration-ambient: 6s;
  --ds-ease-standard: cubic-bezier(0.4, 0, 0.2, 1);
  --ds-ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ds-ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);

  /* Z-index */
  --ds-z-base: 0;
  --ds-z-raised: 10;
  --ds-z-sticky: 100;
  --ds-z-overlay: 500;
  --ds-z-modal: 1000;
  --ds-z-toast: 1100;
}

/* ==========================================================================
   Background system — opt-in premium dark navy surface.
   Apply `.ds-bg-premium` to a page wrapper; body/layout untouched otherwise.
   ========================================================================== */

.ds-bg-premium {
  position: relative;
  background:
    radial-gradient(60% 50% at 15% 10%, rgba(61, 139, 255, 0.16) 0%, rgba(61, 139, 255, 0) 60%),
    radial-gradient(50% 45% at 85% 0%, rgba(99, 102, 241, 0.12) 0%, rgba(99, 102, 241, 0) 60%),
    radial-gradient(70% 60% at 50% 100%, rgba(29, 78, 216, 0.10) 0%, rgba(29, 78, 216, 0) 60%),
    linear-gradient(180deg, var(--ds-bg-deep) 0%, var(--ds-bg-base) 45%, var(--ds-bg-raised) 100%);
  color: var(--ds-text-primary);
  isolation: isolate;
  overflow: hidden;
}

.ds-bg-premium::before {
  /* soft blurred light sources */
  content: "";
  position: absolute;
  inset: -10%;
  z-index: -2;
  background:
    radial-gradient(38% 28% at 20% 20%, rgba(80, 150, 255, 0.20), transparent 70%),
    radial-gradient(32% 24% at 80% 75%, rgba(120, 100, 255, 0.14), transparent 70%);
  filter: blur(60px);
  pointer-events: none;
}

.ds-bg-premium::after {
  /* lightweight grain, kept subtle */
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  opacity: 0.035;
  pointer-events: none;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='120' height='120'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
  background-size: 180px 180px;
}

/* ==========================================================================
   Glass system
   ========================================================================== */

.glass {
  background: var(--ds-surface-glass);
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  border: 1px solid var(--ds-border-subtle);
  box-shadow: var(--ds-shadow-sm);
}

.glass-card {
  background: var(--ds-surface-glass);
  backdrop-filter: blur(18px) saturate(150%);
  -webkit-backdrop-filter: blur(18px) saturate(150%);
  border: 1px solid var(--ds-border-subtle);
  border-radius: var(--ds-radius-lg);
  box-shadow: var(--ds-shadow-md);
  padding: var(--ds-space-lg);
}

.glass-panel {
  background: var(--ds-surface-glass-strong);
  backdrop-filter: blur(24px) saturate(160%);
  -webkit-backdrop-filter: blur(24px) saturate(160%);
  border: 1px solid var(--ds-border-strong);
  border-radius: var(--ds-radius-xl);
  box-shadow: var(--ds-shadow-lg);
}

.glass-nav {
  background: rgba(10, 17, 32, 0.7);
  backdrop-filter: blur(14px) saturate(130%);
  -webkit-backdrop-filter: blur(14px) saturate(130%);
  border-bottom: 1px solid var(--ds-border-subtle);
}

/* ==========================================================================
   3D utility classes
   ========================================================================== */

.perspective {
  perspective: 1200px;
}

.card-3d {
  transform-style: preserve-3d;
  transition: transform var(--ds-duration-base) var(--ds-ease-out);
  will-change: transform;
}

.card-3d:hover {
  transform: rotateX(4deg) rotateY(-6deg) translateY(-4px);
}

.depth-layer {
  position: relative;
  z-index: var(--ds-z-raised);
}

.float-element {
  animation: ds-float var(--ds-duration-ambient) var(--ds-ease-in-out) infinite;
}

.hover-lift {
  transition: transform var(--ds-duration-base) var(--ds-ease-out),
              box-shadow var(--ds-duration-base) var(--ds-ease-out);
}

.hover-lift:hover {
  transform: translateY(-6px);
  box-shadow: var(--ds-shadow-lg);
}

.tilt-surface {
  transition: transform var(--ds-duration-fast) var(--ds-ease-standard);
  transform: perspective(900px) rotateX(0deg) rotateY(0deg);
}

.tilt-surface:hover {
  transform: perspective(900px) rotateX(2deg) rotateY(-3deg);
}

/* ==========================================================================
   Animation system — subtle, premium. All keyframes namespaced `ds-*`.
   ========================================================================== */

@keyframes ds-fade-up {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes ds-fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes ds-scale-in {
  from { opacity: 0; transform: scale(0.96); }
  to   { opacity: 1; transform: scale(1); }
}

@keyframes ds-float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-8px); }
}

@keyframes ds-shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

@keyframes ds-glow {
  0%, 100% { box-shadow: 0 0 0 1px var(--ds-border-accent), 0 0 16px rgba(61, 139, 255, 0.25); }
  50%      { box-shadow: 0 0 0 1px var(--ds-border-accent), 0 0 32px rgba(61, 139, 255, 0.45); }
}

.fade-up {
  animation: ds-fade-up var(--ds-duration-slow) var(--ds-ease-out) both;
}

.fade-in {
  animation: ds-fade-in var(--ds-duration-base) var(--ds-ease-standard) both;
}

.scale-in {
  animation: ds-scale-in var(--ds-duration-base) var(--ds-ease-out) both;
}

.shimmer {
  background: linear-gradient(90deg, transparent 0%, rgba(255, 255, 255, 0.08) 50%, transparent 100%);
  background-size: 200% 100%;
  animation: ds-shimmer 2.2s linear infinite;
}

.glow {
  animation: ds-glow 3.2s var(--ds-ease-in-out) infinite;
}

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--ds-duration-slow) var(--ds-ease-out),
              transform var(--ds-duration-slow) var(--ds-ease-out);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Scroll-reveal "scale" variant — cards animate in with scale(0.97) -> 1
   alongside the fade, instead of the translateY used by .reveal. Both are
   driven the same way: add the class in markup, JS adds .is-visible when
   the element enters the viewport (see footer.php's shared reveal system). */
.reveal-scale {
  opacity: 0;
  transform: scale(0.97);
  transition: opacity var(--ds-duration-slow) var(--ds-ease-out),
              transform var(--ds-duration-slow) var(--ds-ease-out);
}

.reveal-scale.is-visible {
  opacity: 1;
  transform: scale(1);
}

/* Short, capped stagger for direct children of a revealing grid/row.
   Kept intentionally small (spec: "keep stagger short"). Extend further
   :nth-child rules only if a grid genuinely has more visible-at-once items. */
.reveal-stagger-group > :nth-child(1) { transition-delay: 0ms; }
.reveal-stagger-group > :nth-child(2) { transition-delay: 40ms; }
.reveal-stagger-group > :nth-child(3) { transition-delay: 80ms; }
.reveal-stagger-group > :nth-child(4) { transition-delay: 120ms; }
.reveal-stagger-group > :nth-child(5) { transition-delay: 160ms; }
.reveal-stagger-group > :nth-child(6) { transition-delay: 200ms; }
.reveal-stagger-group > :nth-child(n+7) { transition-delay: 240ms; }

/* ==========================================================================
   Reduced motion
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
  .float-element,
  .shimmer,
  .glow {
    animation: none;
  }

  .fade-up,
  .fade-in,
  .scale-in {
    animation-duration: 1ms;
    animation-iteration-count: 1;
  }

  .card-3d,
  .hover-lift,
  .tilt-surface,
  .reveal,
  .reveal-scale {
    transition-duration: 1ms;
  }

  .reveal-stagger-group > * {
    transition-delay: 0ms !important;
  }

  .reveal-scale.is-visible {
    transform: none;
  }

  .card-3d:hover,
  .tilt-surface:hover {
    transform: none;
  }
}

/* ==========================================================================
   Typography scale — opt-in classes, existing h1/h2/h3 element styles
   in style.css are left untouched.
   ========================================================================== */

.ds-display {
  font-family: var(--ds-font-family);
  font-size: var(--ds-font-size-display);
  line-height: var(--ds-line-height-tight);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.ds-h1 {
  font-family: var(--ds-font-family);
  font-size: var(--ds-font-size-h1);
  line-height: var(--ds-line-height-tight);
  font-weight: 700;
  letter-spacing: -0.015em;
}

.ds-h2 {
  font-family: var(--ds-font-family);
  font-size: var(--ds-font-size-h2);
  line-height: var(--ds-line-height-tight);
  font-weight: 600;
  letter-spacing: -0.01em;
}

.ds-h3 {
  font-family: var(--ds-font-family);
  font-size: var(--ds-font-size-h3);
  line-height: 1.25;
  font-weight: 600;
}

.ds-body {
  font-family: var(--ds-font-family);
  font-size: var(--ds-font-size-body);
  line-height: var(--ds-line-height-normal);
  font-weight: 400;
}

.ds-small {
  font-family: var(--ds-font-family);
  font-size: var(--ds-font-size-small);
  line-height: var(--ds-line-height-normal);
  font-weight: 400;
}

.ds-caption {
  font-family: var(--ds-font-family);
  font-size: var(--ds-font-size-caption);
  line-height: 1.4;
  font-weight: 500;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--ds-text-muted);
}

/* ==========================================================================
   Buttons — namespaced `ds-btn*` so Bootstrap's `.btn-primary` etc.
   (already used across checkout/cart/blog/repair) are never touched.
   ========================================================================== */

.ds-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--ds-space-xs);
  font-family: var(--ds-font-family);
  font-size: var(--ds-font-size-small);
  font-weight: 600;
  border-radius: var(--ds-radius-pill);
  padding: 12px 24px;
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: transform var(--ds-duration-fast) var(--ds-ease-standard),
              box-shadow var(--ds-duration-fast) var(--ds-ease-standard),
              background var(--ds-duration-fast) var(--ds-ease-standard),
              border-color var(--ds-duration-fast) var(--ds-ease-standard);
}

.ds-btn:active {
  transform: translateY(1px) scale(0.98);
}

.ds-btn:focus-visible {
  outline: 2px solid var(--ds-accent);
  outline-offset: 3px;
}

.ds-btn-primary {
  background: linear-gradient(180deg, var(--ds-accent) 0%, var(--ds-accent-strong) 100%);
  color: #ffffff;
  box-shadow: var(--ds-shadow-sm);
}

.ds-btn-primary:hover {
  box-shadow: var(--ds-shadow-glow);
  transform: translateY(-2px);
}

.ds-btn-secondary {
  background: var(--ds-surface-2);
  color: var(--ds-text-primary);
  border-color: var(--ds-border-subtle);
}

.ds-btn-secondary:hover {
  background: var(--ds-surface-1);
  border-color: var(--ds-border-strong);
  transform: translateY(-2px);
}

.ds-btn-outline {
  background: transparent;
  color: var(--ds-accent);
  border-color: var(--ds-border-accent);
}

.ds-btn-outline:hover {
  background: var(--ds-accent-soft);
  transform: translateY(-2px);
}

.ds-btn-ghost {
  background: transparent;
  color: var(--ds-text-secondary);
  border-color: transparent;
}

.ds-btn-ghost:hover {
  background: rgba(255, 255, 255, 0.06);
  color: var(--ds-text-primary);
}

.ds-icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--ds-surface-2);
  border: 1px solid var(--ds-border-subtle);
  color: var(--ds-text-primary);
  cursor: pointer;
  transition: transform var(--ds-duration-fast) var(--ds-ease-standard),
              box-shadow var(--ds-duration-fast) var(--ds-ease-standard);
}

.ds-icon-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--ds-shadow-sm);
}

/* ==========================================================================
   Cards — namespaced `ds-card` so Bootstrap's `.card` (used across
   checkout/cart/blog/trade-in/repair) is never touched.
   ========================================================================== */

.ds-card {
  position: relative;
  background: var(--ds-surface-1);
  border: 1px solid var(--ds-border-subtle);
  border-radius: var(--ds-radius-lg);
  overflow: hidden;
  color: var(--ds-text-primary);
  transition: transform var(--ds-duration-base) var(--ds-ease-out),
              box-shadow var(--ds-duration-base) var(--ds-ease-out),
              border-color var(--ds-duration-base) var(--ds-ease-out);
}

.ds-card:hover {
  transform: translateY(-6px) scale(1.01);
  box-shadow: var(--ds-shadow-lg);
  border-color: var(--ds-border-strong);
}

.ds-card-media {
  position: relative;
  overflow: hidden;
  aspect-ratio: 4 / 3;
}

.ds-card-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--ds-duration-slow) var(--ds-ease-out);
}

.ds-card:hover .ds-card-media img {
  transform: scale(1.06);
}

.ds-card-body {
  padding: var(--ds-space-md);
}

.ds-card-title {
  font-family: var(--ds-font-family);
  font-size: var(--ds-font-size-h3);
  font-weight: 600;
  line-height: 1.3;
  margin: 0 0 var(--ds-space-2xs);
}

.ds-card-text {
  font-family: var(--ds-font-family);
  font-size: var(--ds-font-size-small);
  color: var(--ds-text-secondary);
  line-height: var(--ds-line-height-normal);
  margin: 0;
}

@media (prefers-reduced-motion: reduce) {
  .ds-btn,
  .ds-btn-primary,
  .ds-btn-secondary,
  .ds-btn-outline,
  .ds-btn-ghost,
  .ds-icon-btn,
  .ds-card,
  .ds-card-media img {
    transition-duration: 1ms;
  }

  .ds-btn:hover,
  .ds-btn-primary:hover,
  .ds-btn-secondary:hover,
  .ds-btn-outline:hover,
  .ds-icon-btn:hover,
  .ds-card:hover {
    transform: none;
  }
}