/* ── Design Tokens ─────────────────────────────────────────── */
:root {
  --color-bg: #0d0d0d;
  --color-bg-alt: #141414;
  --color-card: #1a1a1a;
  --color-card-border: rgba(184, 134, 11, 0.2);
  --color-text: #f0f0f0;
  --color-text-secondary: #999;
  --color-accent: #f5c542;
  --color-link: #4ecdc4;
  --color-battery-good: #4ecdc4;
  --color-battery-bad: #ff6b6b;
  --font-heading: 'Space Mono', 'Courier New', monospace;
  --font-body: 'Inter', system-ui, sans-serif;
  --max-width: 960px;
  --transition: 0.2s ease;
  --radius-sm: 6px;
  --radius-md: 12px;
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 4rem;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

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

a:hover {
  text-decoration: underline;
}

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

:focus:not(:focus-visible) {
  outline: none;
}

h1, h2, h3 {
  font-family: var(--font-heading);
  line-height: 1.2;
}

/* ── Language Switcher ────────────────────────────────────── */
.lang-toggle {
  position: fixed;
  top: 1rem;
  right: 1rem;
  z-index: 100;
  display: grid;
  grid-template-columns: 1fr 1fr;
  width: 5rem;
  height: 2rem;
  background: rgba(26, 26, 26, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid var(--color-card-border);
  border-radius: 50px;
  padding: 0;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  user-select: none;
}

.lang-toggle-slider {
  position: absolute;
  top: 3px;
  left: 3px;
  width: calc(50% - 3px);
  height: calc(100% - 6px);
  background: var(--color-accent);
  border-radius: 50px;
  transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  pointer-events: none;
}

[data-lang="cs"] .lang-toggle-slider {
  transform: translateX(calc(100% - 1px));
}

.lang-toggle-label {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-text-secondary);
  letter-spacing: 0.05em;
  transition: color 0.25s;
  pointer-events: none;
  z-index: 1;
}

.lang-toggle-label[data-lang="en"] {
  color: var(--color-bg);
}

[data-lang="cs"] .lang-toggle-label[data-lang="en"] {
  color: var(--color-text-secondary);
}

[data-lang="cs"] .lang-toggle-label[data-lang="cs"] {
  color: var(--color-bg);
}

/* ── Hero ─────────────────────────────────────────────────── */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 2rem 1.5rem;
  position: relative;
}

.hero-content {
  max-width: 600px;
}

/* Typewriter */
.typewriter {
  font-size: clamp(1.6rem, 6vw, 3rem);
  color: var(--color-accent);
  white-space: nowrap;
  overflow: hidden;
  border-right: 3px solid var(--color-accent);
  width: 0;
  animation: typewriter 1.5s steps(20) 0.3s forwards, blink 0.7s step-end infinite;
  margin: 0 auto 1rem;
}

@keyframes typewriter {
  to { width: var(--tw-width); }
}

@keyframes blink {
  50% { border-color: transparent; }
}

.hero-subtitle {
  color: var(--color-text-secondary);
  font-size: 1.05rem;
  margin-bottom: 2rem;
  opacity: 0;
  animation: fadeIn 0.6s 2s forwards;
}

.hero-pcb {
  max-width: 280px;
  margin: 0 auto 2rem;
  transform: rotate(3deg);
  opacity: 0;
  animation: fadeSlideUp 0.8s 1.8s forwards;
}

@keyframes fadeSlideUp {
  from {
    opacity: 0;
    transform: rotate(3deg) translateY(20px);
  }
  to {
    opacity: 1;
    transform: rotate(3deg) translateY(0);
  }
}

@keyframes fadeIn {
  to { opacity: 1; }
}

/* CTA buttons */
.hero-ctas {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
  opacity: 0;
  animation: fadeIn 0.6s 2.2s forwards;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.75rem;
  border-radius: 50px;
  font-family: var(--font-heading);
  font-size: 0.9rem;
  font-weight: 700;
  text-decoration: none;
  transition: transform 0.2s, box-shadow 0.2s;
}

.btn:hover {
  transform: translateY(-2px);
  text-decoration: none;
}

.btn-primary {
  background: var(--color-accent);
  color: var(--color-bg);
}

.btn-primary:hover {
  box-shadow: 0 4px 20px rgba(245, 197, 66, 0.35);
}

.btn-secondary {
  background: transparent;
  color: var(--color-link);
  border: 2px solid var(--color-link);
}

.btn-secondary:hover {
  background: rgba(78, 205, 196, 0.1);
  box-shadow: 0 4px 20px rgba(78, 205, 196, 0.2);
}

/* Scroll chevron */
.scroll-chevron {
  position: absolute;
  bottom: 2rem;
  color: var(--color-text-secondary);
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(8px); }
}

/* ── What Is This? ────────────────────────────────────────── */
.what-is-this {
  background: var(--color-bg-alt);
  padding: 4rem 1.5rem;
  text-align: center;
}

.bridge-text {
  max-width: 600px;
  margin: 0 auto;
  font-size: 1.15rem;
  color: var(--color-text-secondary);
  line-height: 1.8;
}

/* ── Mode Showcase ────────────────────────────────────────── */
.modes {
  padding: 4rem 1.5rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

.modes h2 {
  text-align: center;
  color: var(--color-accent);
  font-size: clamp(1.5rem, 4vw, 2rem);
  margin-bottom: 2.5rem;
}

.mode-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

.mode-card {
  background: var(--color-card);
  border: 1px solid var(--color-card-border);
  border-radius: 12px;
  padding: 1.75rem 1.5rem 1.25rem;
  position: relative;
  overflow: hidden;
  transition: transform 0.2s, box-shadow 0.2s;
  display: flex;
  flex-direction: column;
}

.mode-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
}

.card-accent {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--accent);
}

.card-number {
  position: absolute;
  top: 0.5rem;
  right: 1rem;
  font-family: var(--font-heading);
  font-size: 3.5rem;
  font-weight: 700;
  color: var(--accent);
  opacity: 0.12;
  line-height: 1;
}

.mode-card h3 {
  color: var(--accent);
  font-size: 1.25rem;
  margin-bottom: 0.25rem;
}

.card-tagline {
  font-style: italic;
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.card-stats {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.card-stats li {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  color: var(--color-text-secondary);
}

.card-stats .icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  stroke: var(--accent);
}

.card-special {
  color: var(--accent) !important;
  font-size: 0.85rem !important;
  padding-left: 26px;
  font-weight: 700;
}

/* Battery bar */
.battery-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-top: auto;
  padding-top: 0.75rem;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.battery-label {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  white-space: nowrap;
  min-width: 90px;
  font-family: var(--font-heading);
}

.battery-track {
  flex: 1;
  height: 8px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 4px;
  overflow: hidden;
}

.battery-bar {
  height: 100%;
  width: 0;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--color-battery-bad), var(--color-battery-good));
  transition: width 1s ease-out;
}

.battery-bar.visible {
  width: calc(var(--fill) * 1%);
}

/* ── Getting Started ──────────────────────────────────────── */
.getting-started {
  background: var(--color-bg-alt);
  padding: 4rem 1.5rem;
}

.getting-started h2 {
  text-align: center;
  color: var(--color-accent);
  font-size: clamp(1.5rem, 4vw, 2rem);
  margin-bottom: 3rem;
}

.step {
  max-width: 720px;
  margin: 0 auto 3rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.step:last-child {
  margin-bottom: 0;
}

.step-text {
  position: relative;
}

.step-number {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-accent);
  width: 56px;
  height: 56px;
  border: 3px solid var(--color-accent);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
}

.step-text h3 {
  font-size: 1.3rem;
  margin-bottom: 0.75rem;
  color: var(--color-text);
}

.step-text p {
  color: var(--color-text-secondary);
  margin-bottom: 0.5rem;
  line-height: 1.7;
}

.step-image img {
  border-radius: 12px;
  max-width: 320px;
}

.step-image-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  max-width: 320px;
}

.step-image-placeholder svg {
  width: 200px;
  height: 200px;
}

/* Fade-in on scroll */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── Footer ───────────────────────────────────────────────── */
.footer {
  padding: 3rem 1.5rem;
  text-align: center;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.footer p {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  margin-bottom: 0.75rem;
}

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

.footer-links {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-heading);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.footer-links .separator {
  color: var(--color-text-secondary);
}

.footer-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.footer-links svg {
  color: var(--color-text-secondary);
  fill: currentColor;
}

.footer-credit {
  color: var(--color-text-secondary);
}

.footer-easter-egg {
  color: var(--color-text-secondary);
  font-style: italic;
  opacity: 0.5;
  font-size: 0.8rem !important;
  margin-top: 1rem !important;
}

/* ── Responsive ───────────────────────────────────────────── */

/* Tablet small */
@media (min-width: 480px) {
  .mode-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Tablet */
@media (min-width: 768px) {
  .step {
    flex-direction: row;
    align-items: center;
    max-width: var(--max-width);
  }

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

  .step-text {
    flex: 1;
  }

  .step-image {
    flex-shrink: 0;
  }
}

/* Desktop */
@media (min-width: 1024px) {
  .mode-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .modes {
    max-width: var(--max-width);
  }
}

/* ── Reduced Motion ───────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .typewriter {
    width: 100%;
    border-right: none;
  }

  .hero-subtitle,
  .hero-pcb,
  .hero-ctas {
    opacity: 1;
  }

  .fade-in {
    opacity: 1;
    transform: none;
  }

  .battery-bar {
    transition: none;
  }
}