/* ============================================
   POS-Shop — Base Styles
   Reset, Typography, Global Styles
   ============================================ */

/* === Modern Reset === */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  min-height: 100vh;
  overflow-x: hidden;
}

/* Background gradient mesh */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse at 20% 0%, rgba(59, 130, 246, 0.08) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 100%, rgba(245, 158, 11, 0.05) 0%, transparent 50%),
    radial-gradient(ellipse at 50% 50%, rgba(99, 102, 241, 0.03) 0%, transparent 70%);
  pointer-events: none;
  z-index: -1;
}

img, picture, video, canvas, svg {
  display: block;
  max-width: 100%;
}

input, button, textarea, select {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  border: none;
  background: none;
}

a {
  color: var(--color-text-link);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-300);
}

ul, ol {
  list-style: none;
}

/* === Typography === */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: var(--weight-bold);
  line-height: var(--leading-tight);
  color: var(--color-text-primary);
}

h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-2xl); }
h4 { font-size: var(--text-xl); }
h5 { font-size: var(--text-lg); }
h6 { font-size: var(--text-base); }

p {
  color: var(--color-text-secondary);
  margin-bottom: var(--space-4);
}

p:last-child {
  margin-bottom: 0;
}

small {
  font-size: var(--text-sm);
  color: var(--color-text-tertiary);
}

strong {
  font-weight: var(--weight-semibold);
}

code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--color-bg-tertiary);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
}

/* === Scrollbar === */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--color-bg-tertiary);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-tertiary);
}

/* === Selection === */
::selection {
  background: var(--color-primary-600);
  color: white;
}

/* === Focus Styles === */
:focus-visible {
  outline: 2px solid var(--color-primary-500);
  outline-offset: 2px;
}

/* === Layout Helpers === */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* === App Layout === */
#app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

#app-header {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  height: var(--header-height);
  background: var(--color-bg-glass);
  backdrop-filter: blur(20px) saturate(1.5);
  -webkit-backdrop-filter: blur(20px) saturate(1.5);
  border-bottom: 1px solid var(--color-border);
}

#app-main {
  flex: 1;
  display: flex;
  flex-direction: column;
}

#app-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-8) 0;
  background: var(--color-bg-secondary);
}

/* === Page Transitions === */
.page-enter {
  animation: pageEnter var(--transition-base) ease-out;
}

@keyframes pageEnter {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.page-exit {
  animation: pageExit var(--transition-fast) ease-in;
}

@keyframes pageExit {
  from {
    opacity: 1;
    transform: translateY(0);
  }
  to {
    opacity: 0;
    transform: translateY(-4px);
  }
}

/* === Loading States === */
.skeleton {
  background: linear-gradient(
    90deg,
    var(--color-bg-tertiary) 0%,
    var(--color-bg-secondary) 50%,
    var(--color-bg-tertiary) 100%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-md);
}

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

.spinner {
  width: 24px;
  height: 24px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-primary-500);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* === Responsive === */
@media (max-width: 768px) {
  .container {
    padding: 0 var(--space-4);
  }

  h1 { font-size: var(--text-3xl); }
  h2 { font-size: var(--text-2xl); }
  h3 { font-size: var(--text-xl); }
}

@media (max-width: 480px) {
  html {
    font-size: 14px;
  }

  .container {
    padding: 0 var(--space-3);
  }
}