/* ========================================================================
   Variables
   ======================================================================== */
:root {
  /* Colors */
  --color-bg: #020617; /* deep space */
  --color-bg-elevated: #02091f;
  --color-bg-soft: #020817;
  --color-surface: #070b24;
  --color-surface-soft: #0b102b;

  --color-text: #e5e7eb;
  --color-text-soft: #9ca3af;
  --color-text-muted: #6b7280;

  --color-primary: #38bdf8; /* solar blue */
  --color-primary-soft: rgba(56, 189, 248, 0.16);
  --color-primary-strong: #0ea5e9;

  --color-success: #22c55e;
  --color-warning: #eab308;
  --color-danger: #ef4444;

  --color-border-subtle: rgba(148, 163, 184, 0.25);
  --color-border-strong: rgba(148, 163, 184, 0.45);

  --color-neutral-50:  #f9fafb;
  --color-neutral-100: #f3f4f6;
  --color-neutral-200: #e5e7eb;
  --color-neutral-300: #d1d5db;
  --color-neutral-400: #9ca3af;
  --color-neutral-500: #6b7280;
  --color-neutral-600: #4b5563;
  --color-neutral-700: #374151;
  --color-neutral-800: #1f2937;
  --color-neutral-900: #111827;

  /* Accent glows */
  --glow-cyan: 0 0 30px rgba(56, 189, 248, 0.55);
  --glow-purple: 0 0 40px rgba(168, 85, 247, 0.55);
  --glow-soft: 0 0 18px rgba(94, 234, 212, 0.35);

  /* Typography */
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, sans-serif;
  --font-heading: "SF Pro Display", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

  --text-xs: 0.75rem;  /* 12px */
  --text-sm: 0.875rem; /* 14px */
  --text-md: 1rem;     /* 16px */
  --text-lg: 1.125rem; /* 18px */
  --text-xl: 1.25rem;  /* 20px */
  --text-2xl: 1.5rem;  /* 24px */
  --text-3xl: 1.875rem;/* 30px */
  --text-4xl: 2.25rem; /* 36px */
  --text-5xl: 3rem;    /* 48px */

  --leading-tight: 1.15;
  --leading-snug: 1.3;
  --leading-normal: 1.5;
  --leading-relaxed: 1.7;

  /* Spacing scale (px) */
  --space-0: 0;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-7: 28px;
  --space-8: 32px;
  --space-9: 36px;
  --space-10: 40px;
  --space-12: 48px;
  --space-14: 56px;
  --space-16: 64px;
  --space-20: 80px;
  --space-24: 96px;

  /* Radius */
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-pill: 999px;

  /* Shadows & glows */
  --shadow-soft: 0 18px 45px rgba(15, 23, 42, 0.75);
  --shadow-elevated: 0 24px 70px rgba(15, 23, 42, 0.95);
  --shadow-border: 0 0 0 1px rgba(148, 163, 184, 0.35);

  /* Transitions */
  --transition-fast: 120ms ease-out;
  --transition-normal: 180ms ease-out;
  --transition-slow: 260ms ease-out;

  /* Layout */
  --container-width: 1120px;
  --container-padding-x: 20px;
}

/* Motion-safe overrides */
@media (prefers-reduced-motion: reduce) {
  :root {
    --transition-fast: 0ms;
    --transition-normal: 0ms;
    --transition-slow: 0ms;
  }
}

/* ========================================================================
   Reset / Normalize
   ======================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  margin: 0;
  padding: 0;
  scroll-behavior: smooth;
  text-size-adjust: 100%;
}

body {
  margin: 0;
}

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

ul[role='list'],
ol[role='list'] {
  list-style: none;
  margin: 0;
  padding: 0;
}

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

img {
  height: auto;
}

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

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

a {
  color: inherit;
  text-decoration: none;
}

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

[hidden] {
  display: none !important;
}

/* ========================================================================
   Base
   ======================================================================== */
body {
  min-height: 100vh;
  font-family: var(--font-sans);
  font-size: var(--text-md);
  line-height: var(--leading-normal);
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

main {
  display: block;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 650;
  line-height: var(--leading-tight);
  letter-spacing: 0.02em;
  color: #f9fafb;
}

h1 {
  font-size: clamp(2.4rem, 3.2vw + 1rem, 3.4rem);
  margin-bottom: var(--space-4);
}

h2 {
  font-size: clamp(1.9rem, 2.4vw + 0.9rem, 2.4rem);
  margin-bottom: var(--space-3);
}

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

h4 {
  font-size: 1.25rem;
  margin-bottom: var(--space-2);
}

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

strong {
  font-weight: 600;
  color: var(--color-text);
}

code, pre {
  font-family: var(--font-mono);
}

pre {
  padding: var(--space-3);
  border-radius: var(--radius-md);
  background: rgba(15, 23, 42, 0.9);
  overflow-x: auto;
}

ul, ol {
  margin: 0 0 var(--space-3);
  padding-left: var(--space-5);
}

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

hr {
  border: none;
  border-top: 1px solid rgba(148, 163, 184, 0.25);
  margin: var(--space-6) 0;
}

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

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

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

/* Layout helpers */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--container-padding-x);
  padding-right: var(--container-padding-x);
}

.section {
  padding-top: var(--space-12);
  padding-bottom: var(--space-12);
}

.section--tight {
  padding-top: var(--space-8);
  padding-bottom: var(--space-8);
}

@media (min-width: 768px) {
  .section {
    padding-top: var(--space-16);
    padding-bottom: var(--space-16);
  }
}

/* Flex utilities */
.flex {
  display: flex;
}

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

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

.flex-row {
  flex-direction: row;
}

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

.items-center {
  align-items: center;
}

.items-start {
  align-items: flex-start;
}

.items-end {
  align-items: flex-end;
}

.justify-center {
  justify-content: center;
}

.justify-between {
  justify-content: space-between;
}

.justify-start {
  justify-content: flex-start;
}

.justify-end {
  justify-content: flex-end;
}

.gap-xs {
  gap: var(--space-2);
}

.gap-sm {
  gap: var(--space-3);
}

.gap-md {
  gap: var(--space-4);
}

.gap-lg {
  gap: var(--space-6);
}

/* Grid utilities */
.grid {
  display: grid;
}

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

@media (min-width: 900px) {
  .grid-2 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(1, minmax(0, 1fr));
  gap: var(--space-6);
}

@media (min-width: 1024px) {
  .grid-3 {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* Text alignment */
.text-center {
  text-align: center;
}

.text-left {
  text-align: left;
}

.text-right {
  text-align: right;
}

/* 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;
}

/* Space-themed backgrounds & overlays (for hero and sections) */
.space-bg {
  position: relative;
  background: radial-gradient(circle at 10% 0%, rgba(56, 189, 248, 0.16) 0, transparent 55%),
              radial-gradient(circle at 80% 10%, rgba(147, 51, 234, 0.16) 0, transparent 55%),
              radial-gradient(circle at 50% 80%, rgba(56, 189, 248, 0.1) 0, transparent 55%),
              #020617;
}

section.space-bg {
  overflow: hidden;
}

.space-bg::before {
  content: "";
  position: absolute;
  inset: -40%;
  background-image: radial-gradient(circle, rgba(148, 163, 184, 0.25) 1px, transparent 0);
  background-size: 22px 22px;
  opacity: 0.12;
  pointer-events: none;
}

.space-bg-layer {
  position: relative;
  z-index: 1;
}

/* Glow utility */
.glow-primary {
  box-shadow: var(--glow-cyan);
}

.glow-soft {
  box-shadow: var(--glow-soft);
}

/* Max-width helpers for long-form content (e.g., Polish description) */
.prose p + p {
  margin-top: var(--space-3);
}

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

/* Buttons (base) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-pill);
  font-size: var(--text-md);
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  border: 1px solid transparent;
  cursor: pointer;
  transition:
    background-color var(--transition-normal),
    color var(--transition-normal),
    border-color var(--transition-normal),
    box-shadow var(--transition-normal),
    transform var(--transition-fast);
  position: relative;
  overflow: hidden;
}

.btn::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 0 0, rgba(255, 255, 255, 0.16), transparent 55%);
  opacity: 0;
  transition: opacity var(--transition-normal);
  pointer-events: none;
}

.btn:hover::after {
  opacity: 1;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

.btn:disabled,
.btn[aria-disabled="true"] {
  opacity: 0.55;
  cursor: not-allowed;
  box-shadow: none;
}

/* Primary CTA: e.g. "Pobierz tutaj" */
.btn-primary {
  background: linear-gradient(135deg, #22d3ee, #38bdf8, #6366f1);
  color: #0b1120;
  box-shadow: var(--shadow-elevated), var(--glow-cyan);
}

.btn-primary:hover {
  filter: brightness(1.05);
}

.btn-primary:focus-visible {
  outline: 2px solid #e0f2fe;
  outline-offset: 2px;
}

/* Ghost / subtle button (for navigation, etc.) */
.btn-ghost {
  background: rgba(15, 23, 42, 0.7);
  color: var(--color-text);
  border-color: rgba(148, 163, 184, 0.45);
  box-shadow: var(--shadow-soft);
}

.btn-ghost:hover {
  background: rgba(15, 23, 42, 0.95);
  border-color: var(--color-primary);
  box-shadow: var(--shadow-soft), var(--glow-soft);
}

/* Store-specific buttons (Google Play / App Store) */
.btn-store {
  background: rgba(15, 23, 42, 0.96);
  border-radius: var(--radius-lg);
  padding: 10px 20px;
  border: 1px solid rgba(148, 163, 184, 0.7);
  box-shadow: var(--shadow-soft);
  color: var(--color-text);
  flex: 1;
  min-height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-store img {
  width: 100%;
  height: 32px;
  object-fit: contain;
}

.btn-store-label-main {
  font-size: var(--text-sm);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  opacity: 0.8;
}

.btn-store-label-sub {
  font-size: var(--text-md);
  font-weight: 600;
}

.btn-store:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-soft), var(--glow-soft);
}

/* Inputs */
.input,
textarea,
select {
  width: 100%;
  padding: 10px 12px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border-subtle);
  background-color: rgba(15, 23, 42, 0.95);
  color: var(--color-text);
  font-size: var(--text-md);
  transition:
    border-color var(--transition-normal),
    box-shadow var(--transition-normal),
    background-color var(--transition-normal);
}

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

.input:focus-visible,
textarea:focus-visible,
select:focus-visible {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 1px rgba(56, 189, 248, 0.8), var(--glow-soft);
}

.input[aria-invalid="true"],
textarea[aria-invalid="true"] {
  border-color: var(--color-danger);
}

/* Cards (e.g., for sandbox gameplay, physics, guides) */
.card {
  position: relative;
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  background: radial-gradient(circle at top left, rgba(56, 189, 248, 0.18), transparent 55%),
              radial-gradient(circle at bottom right, rgba(129, 140, 248, 0.2), transparent 60%),
              rgba(15, 23, 42, 0.96);
  border: 1px solid rgba(148, 163, 184, 0.35);
  box-shadow: var(--shadow-soft);
  backdrop-filter: blur(18px);
}

.card--subtle {
  background: rgba(15, 23, 42, 0.9);
  border-color: rgba(148, 163, 184, 0.25);
}

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

.card-title {
  font-size: 1.25rem;
  margin-bottom: 4px;
}

.card-eyebrow {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--color-primary);
  margin-bottom: 6px;
}

.card-body {
  color: var(--color-text-soft);
}

/* Hero-specific helpers (space-themed intro, explosions, planets) */
.hero {
  position: relative;
  padding-top: var(--space-16);
  padding-bottom: var(--space-16);
}

@media (min-width: 900px) {
  .hero {
    padding-top: var(--space-20);
    padding-bottom: var(--space-20);
  }
}

.hero-content {
  position: relative;
  z-index: 2;
}

.hero-kicker {
  font-size: var(--text-sm);
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--color-primary);
  margin-bottom: var(--space-2);
}

.hero-subtitle {
  font-size: var(--text-lg);
  max-width: 40rem;
  color: var(--color-text-soft);
}

.hero-cta-row {
  margin-top: var(--space-6);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
}

.hero-badge-row {
  margin-top: var(--space-3);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.hero-orbit-glow {
  position: absolute;
  inset: -10%;
  background:
    radial-gradient(circle at 20% 20%, rgba(56, 189, 248, 0.22) 0, transparent 55%),
    radial-gradient(circle at 80% 10%, rgba(129, 140, 248, 0.26) 0, transparent 55%),
    radial-gradient(circle at 50% 90%, rgba(14, 165, 233, 0.22) 0, transparent 65%);
  opacity: 0.85;
  mix-blend-mode: screen;
  pointer-events: none;
}

/* Tag / pill labels (for modes like Planet Smash, Rozbicie Układu Słonecznego) */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(148, 163, 184, 0.45);
  background: radial-gradient(circle at top left, rgba(56, 189, 248, 0.2), transparent 55%),
              rgba(15, 23, 42, 0.9);
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.16em;
  color: var(--color-text-soft);
}

.tag--primary {
  border-color: rgba(56, 189, 248, 0.7);
  color: var(--color-primary);
}

/* Status badges */
.badge-success {
  color: #bbf7d0;
  background: rgba(34, 197, 94, 0.14);
}

.badge-warning {
  color: #fef3c7;
  background: rgba(234, 179, 8, 0.14);
}

.badge-danger {
  color: #fee2e2;
  background: rgba(239, 68, 68, 0.16);
}

/* FAQ accordion basics */
.faq-item {
  border-radius: var(--radius-md);
  border: 1px solid rgba(148, 163, 184, 0.4);
  background: rgba(15, 23, 42, 0.9);
  padding: var(--space-4);
}

.faq-question {
  font-weight: 600;
  cursor: pointer;
}

.faq-answer {
  margin-top: var(--space-3);
  color: var(--color-text-soft);
}

/* Tables (for stats, tips, strategies) */
.table {
  width: 100%;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid rgba(148, 163, 184, 0.35);
  background: rgba(15, 23, 42, 0.94);
}

.table th,
.table td {
  padding: 10px 12px;
  text-align: left;
  border-bottom: 1px solid rgba(31, 41, 55, 0.9);
}

.table th {
  font-size: var(--text-sm);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-text-muted);
  background: rgba(15, 23, 42, 0.98);
}

.table tbody tr:nth-child(even) {
  background: rgba(15, 23, 42, 0.9);
}

/* Alerts (e.g., epilepsy warning) */
.alert {
  border-radius: var(--radius-md);
  padding: var(--space-4);
  border: 1px solid transparent;
  display: flex;
  gap: var(--space-3);
}

.alert-title {
  font-weight: 600;
  margin-bottom: 4px;
}

.alert-warning {
  background: rgba(251, 191, 36, 0.1);
  border-color: rgba(251, 191, 36, 0.6);
  color: #fef3c7;
}

.alert-danger {
  background: rgba(239, 68, 68, 0.1);
  border-color: rgba(239, 68, 68, 0.7);
  color: #fee2e2;
}

/* Navigation bar */
.navbar {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(16px);
  background: linear-gradient(to bottom, rgba(15, 23, 42, 0.96), rgba(15, 23, 42, 0.8));
  border-bottom: 1px solid rgba(148, 163, 184, 0.3);
}

.navbar-inner {
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  font-size: var(--text-sm);
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.nav-link {
  padding: 4px 0;
  position: relative;
  color: var(--color-text-soft);
}

.nav-link::after {
  content: "";
  position: absolute;
  inset-inline: 0;
  bottom: -4px;
  height: 2px;
  border-radius: 999px;
  background: linear-gradient(90deg, #22d3ee, #38bdf8, #6366f1);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform var(--transition-normal);
}

.nav-link:hover,
.nav-link[aria-current="page"] {
  color: #f9fafb;
}

.nav-link:hover::after,
.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
}

/* Footer */
.footer {
  border-top: 1px solid rgba(148, 163, 184, 0.35);
  background: radial-gradient(circle at top, rgba(56, 189, 248, 0.2), transparent 55%),
              #020617;
  padding-top: var(--space-8);
  padding-bottom: var(--space-8);
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}

.footer a {
  color: var(--color-text-soft);
}

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