:root {
  --primary: #4CAF50;
  --primary-dark: #388E3C;
  --primary-light: #E8F5E9;
  --text: #333;
  --text-light: #666;
  --bg: #fff;
  --bg-alt: #f8f9fa;
  --border: #e0e0e0;
  --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.12);
  --max-width: 960px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}

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

a:hover {
  text-decoration: underline;
}

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

/* ── Site Nav ── */

.site-nav {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  padding: 0.75rem 1rem;
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-nav-logo {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--primary-dark);
  text-decoration: none;
}

.site-nav-logo:hover {
  text-decoration: none;
}

.site-nav-links {
  list-style: none;
  display: flex;
  gap: 1.5rem;
}

.site-nav-links a {
  color: var(--text);
  font-size: 0.95rem;
  font-weight: 500;
  text-decoration: none;
  padding: 0.25rem 0;
  border-bottom: 2px solid transparent;
  transition: border-color 0.2s;
}

.site-nav-links a:hover,
.site-nav-links a.active {
  border-bottom-color: var(--primary);
  text-decoration: none;
}

/* ── Buttons ── */

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  text-align: center;
  transition: transform 0.15s, box-shadow 0.15s;
  cursor: pointer;
  border: none;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
  text-decoration: none;
}

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

.btn-outline {
  background: transparent;
  color: var(--primary-dark);
  border: 2px solid var(--primary);
}

.btn-group {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

/* ── Hero ── */

.hero {
  text-align: center;
  padding: 3rem 1rem 2rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--text);
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.hero .subline {
  font-size: 1.15rem;
  color: var(--text-light);
  max-width: 520px;
  margin: 0 auto 2rem;
}

.hero .btn-group {
  justify-content: center;
  margin-bottom: 2.5rem;
}

.hero-screenshot {
  max-width: 300px;
  margin: 0 auto;
  border-radius: 16px;
  box-shadow: var(--shadow-lg);
}

/* ── Section shared ── */

.section {
  padding: 3rem 1rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-alt {
  background: var(--bg-alt);
}

.section-alt .section {
  padding-top: 3rem;
  padding-bottom: 3rem;
}

.section h2 {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--text);
  text-align: center;
  margin-bottom: 2rem;
}

/* ── Cards grid ── */

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
}

.card {
  background: var(--bg);
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: var(--shadow);
}

.section-alt .card {
  background: var(--bg);
}

.card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.card p {
  color: var(--text-light);
  font-size: 0.95rem;
}

/* ── Feature showcase ── */

.showcase {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 2rem;
  text-align: center;
}

.showcase-item img {
  max-width: 260px;
  border-radius: 12px;
  box-shadow: var(--shadow);
  margin-bottom: 1rem;
}

.showcase-item p {
  color: var(--text-light);
  font-weight: 500;
}

/* ── Authenticity section ── */

.authenticity {
  max-width: 640px;
  margin: 0 auto;
  text-align: center;
}

.authenticity p {
  color: var(--text-light);
  font-size: 1.05rem;
  font-style: italic;
  line-height: 1.7;
}

/* ── Footer ── */

.site-footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  padding: 3rem 1rem;
  text-align: center;
}

.site-footer .btn-group {
  justify-content: center;
  margin-bottom: 1.5rem;
}

.footer-links {
  list-style: none;
  display: flex;
  gap: 1.5rem;
  justify-content: center;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--text-light);
  font-size: 0.9rem;
}

.site-footer .credit {
  color: var(--text-light);
  font-size: 0.85rem;
}

/* ── Help page specifics ── */

.help-nav {
  background: var(--bg-alt);
  border-bottom: 1px solid var(--border);
  padding: 0.75rem 1rem;
}

.help-nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem;
  max-width: var(--max-width);
  margin: 0 auto;
}

.help-nav a {
  color: var(--text);
  padding: 0.4rem 0.75rem;
  border-radius: 4px;
  font-size: 0.85rem;
  transition: background 0.2s;
}

.help-nav a:hover {
  background: var(--border);
  text-decoration: none;
}

.help-header {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
  padding: 1.5rem 1rem;
  text-align: center;
}

.help-header h1 {
  font-size: 1.8rem;
  margin-bottom: 0.25rem;
}

.help-header p {
  color: #fff;
  font-size: 1rem;
}

.help-content {
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 1rem;
}

.help-content section {
  margin-bottom: 4rem;
  scroll-margin-top: 120px;
}

.help-content h2 {
  color: var(--primary-dark);
  font-size: 1.8rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--primary);
  text-align: left;
}

.help-content h3 {
  color: var(--text);
  font-size: 1.3rem;
  margin: 1.5rem 0 0.75rem;
}

.help-content p {
  margin-bottom: 1rem;
  color: var(--text-light);
}

.help-content ul,
.help-content ol {
  margin: 1rem 0 1rem 1.5rem;
  color: var(--text-light);
}

.help-content li {
  margin-bottom: 0.5rem;
}

.feature-card {
  background: var(--bg-alt);
  border-radius: 12px;
  padding: 1.5rem;
  margin: 1.5rem 0;
  box-shadow: var(--shadow);
}

.feature-card h3 {
  margin-top: 0;
  color: var(--primary-dark);
}

.screenshot {
  max-width: 300px;
  margin: 1rem auto;
  display: block;
  border-radius: 12px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.screenshot-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
  margin: 1.5rem 0;
}

.screenshot-row img {
  max-width: 280px;
  border-radius: 12px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.screenshot-wide {
  max-width: 100%;
  margin: 1rem auto;
  display: block;
  border-radius: 12px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.tip {
  background: var(--primary-light);
  border-left: 4px solid var(--primary);
  padding: 1rem;
  margin: 1rem 0;
  border-radius: 0 8px 8px 0;
}

.tip strong {
  color: var(--primary-dark);
}

/* ── Responsive ── */

@media (max-width: 600px) {
  .hero h1 {
    font-size: 2rem;
  }

  .hero .subline {
    font-size: 1rem;
  }

  .btn-group {
    flex-direction: column;
    align-items: stretch;
  }

  .cards {
    grid-template-columns: 1fr;
  }

  .showcase {
    grid-template-columns: 1fr;
  }

  .screenshot {
    max-width: 100%;
  }

  .screenshot-row img {
    max-width: 100%;
  }

  .help-header h1 {
    font-size: 1.5rem;
  }

  .help-nav a {
    padding: 0.3rem 0.5rem;
    font-size: 0.78rem;
  }
}