:root {
  /* Colors */
  --color-bg: #f5f7fa;
  --color-surface: #ffffff;
  --color-text: #111827;
  --color-text-muted: #6b7280;
  --color-primary: #0ea5e9; /* energetic blue */
  --color-primary-soft: #e0f2fe;
  --color-accent: #22c55e; /* fresh green */
  --color-success: #16a34a;
  --color-warning: #f59e0b;
  --color-danger: #ef4444;
  --color-border: #e5e7eb;
  --color-focus: #22c55e;

  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2933;
  --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-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-height-tight: 1.2;
  --line-height-snug: 1.35;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.7;

  /* Spacing scale (0–96px) */
  --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;
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Shadows (crisp, modern) */
  --shadow-xs: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.1), 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 4px 8px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 10px 25px rgba(15, 23, 42, 0.12);

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

/* =============================
   RESET / NORMALIZE
   ============================= */

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

* {
  margin: 0;
}

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

body {
  min-height: 100vh;
}

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

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

button {
  border: none;
  background: none;
  padding: 0;
  color: inherit;
}

ul,
ol {
  list-style: none;
  padding: 0;
}

/* Improve text rendering on modern browsers */
body,
button,
input,
textarea,
select {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* =============================
   BASE STYLES
   ============================= */

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  background-color: var(--color-bg);
  color: var(--color-text);
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: var(--line-height-tight);
  color: var(--color-text);
}

h1 {
  font-size: clamp(2rem, 3vw, var(--font-size-4xl));
  margin-bottom: var(--space-4);
}

h2 {
  font-size: clamp(1.5rem, 2.3vw, var(--font-size-3xl));
  margin-bottom: var(--space-3);
}

h3 {
  font-size: clamp(1.25rem, 1.8vw, var(--font-size-2xl));
  margin-bottom: var(--space-3);
}

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

h5 {
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-2);
}

h6 {
  font-size: var(--font-size-base);
  margin-bottom: var(--space-1);
}

p {
  margin-bottom: var(--space-3);
  color: var(--color-text-muted);
}

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

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

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

strong {
  font-weight: 600;
}

hr {
  border: none;
  border-top: 1px solid var(--gray-200);
  margin: var(--space-6) 0;
}

/* =============================
   ACCESSIBILITY & MOTION
   ============================= */

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

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}

/* =============================
   UTILITIES
   ============================= */

/* Layout helpers */

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

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

.flex {
  display: flex;
}

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

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

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

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

.grid {
  display: grid;
}

.grid-auto-fit {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-4);
}

/* Spacing utilities (commonly used) */

.mt-0 { margin-top: 0; }
.mt-2 { margin-top: var(--space-2); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mb-0 { margin-bottom: 0; }
.mb-2 { margin-bottom: var(--space-2); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }

.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }
.px-4 { padding-inline: var(--space-4); }
.py-2 { padding-block: var(--space-2); }
.py-3 { padding-block: var(--space-3); }

/* 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: primary, secondary, ghost for sporty CTAs */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: var(--font-size-sm);
  letter-spacing: 0.03em;
  text-transform: uppercase;
  cursor: pointer;
  border: 1px solid transparent;
  transition:
    background-color var(--transition-base),
    color var(--transition-base),
    box-shadow var(--transition-base),
    transform var(--transition-fast),
    border-color var(--transition-base);
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: #ffffff;
  box-shadow: var(--shadow-sm);
}

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

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

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

.btn-secondary:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

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

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

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

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

/* Inputs & form controls */

.input,
select,
textarea {
  width: 100%;
  padding: 0.6rem 0.75rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--gray-300);
  background-color: var(--color-surface);
  color: var(--color-text);
  font-size: var(--font-size-sm);
  transition:
    border-color var(--transition-base),
    box-shadow var(--transition-base),
    background-color var(--transition-base);
}

.input::placeholder,
textarea::placeholder {
  color: var(--gray-400);
}

.input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 1px var(--color-primary-soft);
}

.input:disabled,
select:disabled,
textarea:disabled {
  background-color: var(--gray-100);
  cursor: not-allowed;
}

label {
  display: block;
  margin-bottom: var(--space-1);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--gray-700);
}

/* Card: product, promo, content panels */

.card {
  background-color: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(148, 163, 184, 0.18);
  transition:
    box-shadow var(--transition-base),
    transform var(--transition-base),
    border-color var(--transition-base);
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(56, 189, 248, 0.45);
}

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

.card-title {
  font-size: var(--font-size-lg);
  line-height: var(--line-height-snug);
}

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

.card-actions {
  margin-top: var(--space-4);
  display: flex;
  gap: var(--space-2);
  align-items: center;
}

/* Badges (e.g., "Nowość", "Promocja") */

.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.15rem 0.6rem;
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

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

.badge-success {
  background-color: rgba(34, 197, 94, 0.12);
  color: var(--color-success);
}

.badge-danger {
  background-color: rgba(239, 68, 68, 0.12);
  color: var(--color-danger);
}

/* =============================
   END OF BASE
   ============================= */