:root {
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-text: #1e293b;
  --color-text-muted: #64748b;
  --color-border: #e2e8f0;
  --color-accent: #3b82f6;
  --color-accent-dark: #2563eb;
  --color-accent-light: #eff6ff;
  --max-width: 1100px;
  --radius: 10px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.55;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

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

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

/* Header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--color-text);
  text-decoration: none;
}

.brand-logo {
  width: 28px;
  height: 28px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: 0.95rem;
}

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

.nav-right {
  display: flex;
  align-items: center;
  gap: 18px;
}

.lang-switch {
  display: flex;
  gap: 4px;
  font-size: 0.85rem;
}

.lang-switch a {
  padding: 4px 8px;
  border-radius: 6px;
  text-decoration: none;
  color: var(--color-text-muted);
}

.lang-switch a[aria-current="true"] {
  background: var(--color-accent-light);
  color: var(--color-accent-dark);
  font-weight: 600;
}

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: 6px 10px;
  cursor: pointer;
}

/* Buttons */

.btn {
  display: inline-block;
  padding: 12px 22px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  border: none;
  cursor: pointer;
}

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

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

.btn-disabled {
  background: var(--color-border);
  color: var(--color-text-muted);
  cursor: not-allowed;
}

.btn-disabled:hover {
  background: var(--color-border);
}

/* Hero */

.hero {
  padding: 48px 0 32px;
  text-align: center;
}

.hero-logo {
  width: 56px;
  height: 56px;
  margin: 0 auto 12px;
}

.hero h1 {
  font-size: 2.2rem;
  margin: 0 0 10px;
}

.hero p {
  max-width: 640px;
  margin: 0 auto 20px;
  color: var(--color-text-muted);
  font-size: 1.1rem;
}

/* Sections */

section {
  padding: 40px 0;
}

.section-heading {
  text-align: center;
  margin-bottom: 10px;
}

.section-intro {
  text-align: center;
  color: var(--color-text-muted);
  margin: 0 auto 28px;
  max-width: 560px;
}

/* Features grid */

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 18px;
}

.feature-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px;
}

.feature-icon {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: var(--color-accent-light);
  color: var(--color-accent-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 12px;
}

.feature-icon svg {
  width: 20px;
  height: 20px;
}

.feature-card h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
}

.feature-card p {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

/* Gallery */

.gallery-alt {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.gallery-item {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  cursor: pointer;
  text-align: left;
  padding: 0;
}

.gallery-item img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  object-position: top;
  border-bottom: 1px solid var(--color-border);
}

.gallery-caption {
  padding: 12px 14px;
  font-size: 0.88rem;
  color: var(--color-text-muted);
}

/* Lightbox */

.lightbox {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.85);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 32px;
  z-index: 100;
}

.lightbox.open {
  display: flex;
}

.lightbox-content {
  max-width: min(960px, 100%);
  max-height: 100%;
}

.lightbox-content img {
  max-height: 78vh;
  border-radius: 8px;
  margin: 0 auto;
}

.lightbox-caption {
  color: #f1f5f9;
  text-align: center;
  margin-top: 14px;
  font-size: 0.95rem;
}

.lightbox-close {
  position: absolute;
  top: 24px;
  right: 32px;
  background: none;
  border: none;
  color: #f1f5f9;
  font-size: 2rem;
  line-height: 1;
  cursor: pointer;
}

/* Download */

.requirements {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 24px;
}

.requirements h3 {
  text-align: center;
  margin: 0 0 18px;
  font-size: 1.05rem;
}

.requirements-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 18px;
}

.requirement-label {
  display: block;
  font-size: 0.78rem;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
  margin-bottom: 4px;
}

.requirement-value {
  font-size: 0.92rem;
  color: var(--color-text);
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
}

.download-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
}

.download-card .feature-icon {
  margin: 0 auto 12px;
}

.download-card h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
}

.download-card p {
  margin: 0 0 16px;
  color: var(--color-text-muted);
  font-size: 0.95rem;
}

.how-to-buy {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  margin-top: 24px;
}

.how-to-buy h3 {
  text-align: center;
  margin: 0 0 18px;
  font-size: 1.05rem;
}

.how-to-buy-list {
  margin: 0;
  padding-left: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.how-to-buy-list li {
  font-size: 0.95rem;
  color: var(--color-text);
}

/* About */

.about {
  text-align: center;
}

.about .section-intro {
  margin-bottom: 0;
}

/* Contact */

.contact {
  text-align: center;
}

.contact p {
  color: var(--color-text-muted);
  max-width: 480px;
  margin: 0 auto 28px;
}

.contact-fallback {
  margin-top: 18px;
  font-size: 0.9rem;
  color: var(--color-text-muted);
  min-height: 1.4em;
}

/* Footer */

.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 20px 0;
}

.site-footer .container {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--color-text-muted);
  text-decoration: none;
}

.footer-brand:hover {
  color: var(--color-accent-dark);
}

.footer-logo {
  width: 20px;
  height: 20px;
}

/* Responsive */

@media (max-width: 760px) {
  .nav-links {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    align-items: flex-start;
    padding: 16px 24px;
    gap: 16px;
    display: none;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-toggle {
    display: inline-block;
  }

  .hero h1 {
    font-size: 1.9rem;
  }
}