:root {
  /*
  ======================================================================
  Variables
  ======================================================================
  */

  /* Color palette - cool blues, crisp whites, subtle grays */
  --color-background: #f5f7fa;
  --color-surface: #ffffff;
  --color-surface-muted: #f0f2f7;
  --color-text: #111827;
  --color-text-muted: #6b7280;
  --color-border-subtle: #e5e7eb;

  --color-primary: #2563eb;
  --color-primary-soft: #e0ecff;
  --color-primary-hover: #1d4ed8;
  --color-primary-active: #1e40af;

  --color-success: #16a34a;
  --color-success-soft: #dcfce7;

  --color-warning: #f59e0b;
  --color-warning-soft: #fef3c7;

  --color-danger: #dc2626;
  --color-danger-soft: #fee2e2;

  --color-gray-50: #f9fafb;
  --color-gray-100: #f3f4f6;
  --color-gray-200: #e5e7eb;
  --color-gray-300: #d1d5db;
  --color-gray-400: #9ca3af;
  --color-gray-500: #6b7280;
  --color-gray-600: #4b5563;
  --color-gray-700: #374151;
  --color-gray-800: #1f2933;
  --color-gray-900: #111827;

  /* Typography */
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-heading: system-ui, -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;

  /* Font sizes (rem based for scalability) */
  --font-size-xs: 0.75rem;   /* 12px */
  --font-size-sm: 0.875rem;  /* 14px */
  --font-size-base: 1rem;    /* 16px */
  --font-size-lg: 1.125rem;  /* 18px */
  --font-size-xl: 1.25rem;   /* 20px */
  --font-size-2xl: 1.5rem;   /* 24px */
  --font-size-3xl: 1.875rem; /* 30px */
  --font-size-4xl: 2.25rem;  /* 36px */

  /* Line heights */
  --line-height-tight: 1.2;
  --line-height-snug: 1.35;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.7;

  /* Spacing scale (px values for clarity, used via rem) */
  --space-0: 0;
  --space-1: 0.25rem;  /* 4px */
  --space-2: 0.5rem;   /* 8px */
  --space-3: 0.75rem;  /* 12px */
  --space-4: 1rem;     /* 16px */
  --space-5: 1.25rem;  /* 20px */
  --space-6: 1.5rem;   /* 24px */
  --space-8: 2rem;     /* 32px */
  --space-10: 2.5rem;  /* 40px */
  --space-12: 3rem;    /* 48px */
  --space-16: 4rem;    /* 64px */
  --space-20: 5rem;    /* 80px */
  --space-24: 6rem;    /* 96px */

  /* Radius */
  --radius-xs: 0.125rem; /* 2px */
  --radius-sm: 0.25rem;  /* 4px */
  --radius-md: 0.5rem;   /* 8px */
  --radius-lg: 0.75rem;  /* 12px */
  --radius-xl: 1rem;     /* 16px */
  --radius-pill: 999px;

  /* Shadows: soft, airy, minimal */
  --shadow-xs: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.08), 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 10px 30px rgba(15, 23, 42, 0.08);

  /* Transitions */
  --transition-fast: 120ms ease-out;
  --transition-base: 180ms ease-out;
  --transition-slow: 240ms ease-out;
}

/*
======================================================================
Reset / Normalize
======================================================================
*/

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

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

body {
  margin: 0;
}

h1,
h2,
h3,
h4,
h5,
h6,
p,
figure,
blockquote,
dl,
dd {
  margin: 0;
}

ul,
ol {
  margin: 0;
  padding: 0;
}

button,
input,
select,
textarea {
  font: inherit;
  color: inherit;
  margin: 0;
}

img,
svg,
video,
canvas,
audio,
iframe,
embed,
object {
  display: block;
  max-width: 100%;
}

img {
  height: auto;
}

table {
  border-collapse: collapse;
  border-spacing: 0;
}

[hidden] {
  display: none !important;
}

*,
*::before,
*::after {
  border-style: solid;
  border-width: 0;
}

/*
======================================================================
Base Styles
======================================================================
*/

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-background);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

main {
  min-height: 60vh;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: var(--line-height-tight);
  color: var(--color-gray-900);
}

h1 {
  font-size: clamp(2rem, 2.7vw, var(--font-size-4xl));
  margin-bottom: var(--space-4);
}

h2 {
  font-size: clamp(1.75rem, 2.3vw, var(--font-size-3xl));
  margin-bottom: var(--space-3);
}

h3 {
  font-size: clamp(1.5rem, 2vw, var(--font-size-2xl));
  margin-bottom: var(--space-2);
}

h4 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--space-2);
}

h5 {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-1);
}

h6 {
  font-size: var(--font-size-base);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: var(--space-1);
  color: var(--color-text-muted);
}

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

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

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

strong {
  font-weight: 600;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-base), opacity var(--transition-fast);
}

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

a:active {
  color: var(--color-primary-active);
}

a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

code,
pre {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

hr {
  border: 0;
  border-top: 1px solid var(--color-border-subtle);
  margin: var(--space-6) 0;
}

/*
======================================================================
Accessibility & Motion
======================================================================
*/

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
}

:focus {
  outline: none;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/*
======================================================================
Utilities
======================================================================
*/

/* Layout */

.u-container {
  width: 100%;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-4);
  padding-right: var(--space-4);
}

@media (min-width: 1280px) {
  .u-container {
    max-width: 1320px;
  }
}

.u-flex {
  display: flex;
}

.u-inline-flex {
  display: inline-flex;
}

.u-flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

.u-flex-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.u-flex-column {
  display: flex;
  flex-direction: column;
}

.u-flex-wrap {
  flex-wrap: wrap;
}

.u-grid {
  display: grid;
  gap: var(--space-6);
}

.u-grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-6);
}

.u-grid-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-8);
}

@media (max-width: 768px) {
  .u-grid-2,
  .u-grid-3 {
    grid-template-columns: minmax(0, 1fr);
  }
}

/* Spacing helpers (minimal set) */

.u-mb-0 { margin-bottom: 0 !important; }
.u-mb-2 { margin-bottom: var(--space-2) !important; }
.u-mb-4 { margin-bottom: var(--space-4) !important; }
.u-mb-6 { margin-bottom: var(--space-6) !important; }

.u-pt-6 { padding-top: var(--space-6) !important; }
.u-pb-6 { padding-bottom: var(--space-6) !important; }

/* Alignment & text */

.u-text-center { text-align: center !important; }
.u-text-right { text-align: right !important; }

.u-text-muted { color: var(--color-text-muted) !important; }

/* Screen reader only */

.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;
}

/*
======================================================================
Components
======================================================================
*/

/* Buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1.4rem;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  background-color: var(--color-primary);
  color: #ffffff;
  font-size: var(--font-size-sm);
  font-weight: 500;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  white-space: nowrap;
  transition:
    background-color var(--transition-base),
    border-color var(--transition-base),
    color var(--transition-base),
    box-shadow var(--transition-base),
    transform var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.btn:hover {
  background-color: var(--color-primary-hover);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.btn:active {
  background-color: var(--color-primary-active);
  box-shadow: var(--shadow-xs);
  transform: translateY(0);
}

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

.btn[disabled],
.btn:disabled {
  cursor: not-allowed;
  opacity: 0.6;
  box-shadow: none;
  transform: none;
}

.btn--secondary {
  background-color: var(--color-surface);
  color: var(--color-text);
  border-color: var(--color-gray-200);
  box-shadow: var(--shadow-xs);
}

.btn--secondary:hover {
  background-color: var(--color-surface-muted);
  border-color: var(--color-gray-300);
}

.btn--ghost {
  background-color: transparent;
  color: var(--color-primary);
  border-color: transparent;
  box-shadow: none;
}

.btn--ghost:hover {
  background-color: var(--color-primary-soft);
}

.btn--sm {
  padding: 0.45rem 1rem;
  font-size: var(--font-size-xs);
}

.btn--lg {
  padding: 0.85rem 1.8rem;
  font-size: var(--font-size-base);
}

/* Form elements */

.input,
select,
textarea {
  width: 100%;
  padding: 0.65rem 0.9rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border-subtle);
  background-color: #ffffff;
  color: var(--color-text);
  font-size: var(--font-size-sm);
  line-height: 1.4;
  transition:
    border-color var(--transition-base),
    box-shadow var(--transition-base),
    background-color var(--transition-base);
}

.input::placeholder,
textarea::placeholder {
  color: var(--color-text-muted);
}

.input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 1px rgba(37, 99, 235, 0.1), 0 10px 30px rgba(15, 23, 42, 0.06);
}

.input[disabled],
select[disabled],
textarea[disabled] {
  background-color: var(--color-gray-50);
  color: var(--color-text-muted);
  cursor: not-allowed;
}

textarea {
  min-height: 120px;
  resize: vertical;
}

label {
  display: inline-block;
  margin-bottom: var(--space-1);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-gray-800);
}

.form-help {
  margin-top: var(--space-1);
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

.form-error {
  margin-top: var(--space-1);
  font-size: var(--font-size-xs);
  color: var(--color-danger);
}

/* Card component - used for products, info blocks, etc. */

.card {
  position: relative;
  background-color: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(148, 163, 184, 0.08);
  transition:
    box-shadow var(--transition-base),
    transform var(--transition-base),
    border-color var(--transition-base),
    background-color var(--transition-base);
}

.card--interactive:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-color: rgba(37, 99, 235, 0.16);
}

.card-header {
  margin-bottom: var(--space-3);
}

.card-title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--space-1);
}

.card-subtitle {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.card-body {
  font-size: var(--font-size-sm);
  color: var(--color-text);
}

.card-footer {
  margin-top: var(--space-4);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}

/* Badge / pill (for stock status, labels) */

.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.15rem 0.65rem;
  border-radius: var(--radius-pill);
  font-size: var(--font-size-xs);
  font-weight: 500;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  background-color: var(--color-gray-100);
  color: var(--color-gray-700);
}

.badge--success {
  background-color: var(--color-success-soft);
  color: var(--color-success);
}

.badge--warning {
  background-color: var(--color-warning-soft);
  color: var(--color-warning);
}

.badge--danger {
  background-color: var(--color-danger-soft);
  color: var(--color-danger);
}

/* Subtle section background helper for airy layout */

.section-muted {
  background: linear-gradient(to bottom, #f7f9fc 0%, #ffffff 50%, #f7f9fc 100%);
}