/* ==========================================================================
   Base reset & typography
   ========================================================================== */

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font-base);
  font-size: var(--fs-base);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  transition: background var(--transition-base), color var(--transition-base);
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font-family: inherit; font-size: inherit; }
button { cursor: pointer; }
ul { list-style: none; margin: 0; padding: 0; }
h1, h2, h3, h4, p { margin: 0; }

/* Layout helpers */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-4);
}

.section { padding-block: var(--space-8); }
.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
  flex-wrap: wrap;
}
.section-head h2 { font-size: var(--fs-3xl); font-weight: 800; }
.section-head p { color: var(--color-text-muted); margin-top: var(--space-2); }

.visually-hidden {
  position: absolute; width: 1px; height: 1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap;
}

.skip-link {
  position: absolute;
  top: -48px; left: 0;
  background: var(--color-primary);
  color: #fff;
  padding: var(--space-3) var(--space-4);
  z-index: 1000;
  transition: top var(--transition-fast);
}
.skip-link:focus { top: 0; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  border: none;
  border-radius: var(--radius-full);
  padding: 12px 24px;
  font-weight: 600;
  font-size: var(--fs-sm);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast);
  white-space: nowrap;
}
.btn:active { transform: scale(0.97); }

.btn-primary { background: var(--color-primary); color: #fff; }
.btn-primary:hover { background: var(--color-primary-dark); box-shadow: var(--shadow-md); }

.btn-accent { background: var(--color-accent); color: #fff; }
.btn-accent:hover { background: var(--color-accent-dark); box-shadow: var(--shadow-md); }

.btn-outline { background: transparent; color: var(--color-text); border: 1.5px solid var(--color-border); }
.btn-outline:hover { border-color: var(--color-primary); color: var(--color-primary); }

.btn-ghost { background: transparent; color: var(--color-text); }
.btn-ghost:hover { background: var(--color-surface-alt); }

.btn-sm { padding: 8px 16px; font-size: var(--fs-xs); }
.btn-block { width: 100%; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

/* Badges */
.badge {
  display: inline-block;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: 0.02em;
}
.badge-bestseller { background: #DBEAFE; color: var(--color-primary-dark); }
.badge-new { background: #D1FAE5; color: var(--color-accent-dark); }
.badge-sale { background: #FEE2E2; color: var(--color-danger); }

[data-theme="dark"] .badge-bestseller { background: rgba(37,99,235,0.2); color: #93C5FD; }
[data-theme="dark"] .badge-new { background: rgba(16,185,129,0.2); color: #6EE7B7; }
[data-theme="dark"] .badge-sale { background: rgba(220,38,38,0.2); color: #FCA5A5; }

/* Star ratings */
.stars { color: #F59E0B; font-size: var(--fs-sm); letter-spacing: 1px; }

/* Reveal-on-scroll animation */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.in-view { opacity: 1; transform: translateY(0); }

/* Skeleton loading shimmer */
.skeleton {
  background: linear-gradient(90deg, var(--color-surface-alt) 25%, var(--color-border) 37%, var(--color-surface-alt) 63%);
  background-size: 400% 100%;
  animation: shimmer 1.4s ease infinite;
  border-radius: var(--radius-md);
}
@keyframes shimmer {
  0% { background-position: 100% 50%; }
  100% { background-position: 0 50%; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
  html { scroll-behavior: auto; }
}