/* Material You Inspired Theme */
:root {
  --sys-light-primary: #0b57d0;
  --sys-light-on-primary: #ffffff;
  --sys-light-primary-container: #d3e3fd;
  --sys-light-on-primary-container: #041e49;
  --sys-light-surface: #f3f6fc;
  --sys-light-on-surface: #1f1f1f;
  --sys-light-surface-variant: #e1e3e1;
  --sys-light-on-surface-variant: #444746;
  --sys-light-secondary: #00639b;
  --sys-light-secondary-container: #cce5ff;
  --sys-light-tertiary: #146c2e;
  --sys-light-tertiary-container: #c4eed0;
  --radius-xl: 28px;
  --radius-lg: 16px;
  --radius-md: 12px;
  --spacing-section: 80px;
}

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

body {
  font-family: 'Google Sans', 'Roboto', 'Segoe UI', -apple-system, sans-serif;
  background-color: var(--sys-light-surface);
  color: var(--sys-light-on-surface);
  line-height: 1.6;
}

/* Nav */
.top-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(243, 246, 252, 0.9);
  backdrop-filter: blur(12px);
  padding: 16px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--sys-light-surface-variant);
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 22px;
  font-weight: 500;
  color: var(--sys-light-on-surface);
  text-decoration: none;
}

.brand-logo svg {
  width: 32px;
  height: 32px;
}

.nav-links {
  display: flex;
  gap: 8px;
}

.nav-link {
  text-decoration: none;
  color: var(--sys-light-on-surface-variant);
  font-weight: 500;
  padding: 10px 20px;
  border-radius: 100px;
  transition: all 0.2s;
}

.nav-link:hover {
  background-color: var(--sys-light-surface-variant);
}

.nav-link.active {
  background-color: var(--sys-light-primary-container);
  color: var(--sys-light-on-primary-container);
}

/* Buttons */
.btn-filled {
  background-color: var(--sys-light-primary);
  color: var(--sys-light-on-primary);
  border: none;
  padding: 16px 32px;
  border-radius: 100px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: opacity 0.2s, transform 0.2s;
}

.btn-filled:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

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

.btn-tonal {
  background-color: var(--sys-light-secondary-container);
  color: var(--sys-light-secondary);
  border: none;
  padding: 12px 24px;
  border-radius: 100px;
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: background-color 0.2s;
}

.btn-tonal:hover {
  background-color: #bbdbfa;
}

/* Hero Section */
.hero-box {
  max-width: 1200px;
  margin: 40px auto;
  padding: 60px 24px;
  background-color: var(--sys-light-primary-container);
  border-radius: var(--radius-xl);
  text-align: center;
}

.hero-box h1 {
  font-size: 48px;
  color: var(--sys-light-on-primary-container);
  margin-bottom: 24px;
  line-height: 1.2;
}

.hero-box p {
  font-size: 20px;
  color: var(--sys-light-on-primary-container);
  max-width: 700px;
  margin: 0 auto 40px;
  opacity: 0.9;
}

/* Grid Layouts */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-section) 24px;
}

.section-title {
  text-align: center;
  font-size: 36px;
  margin-bottom: 48px;
  color: var(--sys-light-on-surface);
}

.bento-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.bento-card {
  background-color: #fff;
  padding: 32px;
  border-radius: var(--radius-xl);
  box-shadow: 0 4px 20px rgba(0,0,0,0.03);
}

.bento-card.large {
  grid-column: span 2;
}
@media(max-width: 768px) {
  .bento-card.large { grid-column: span 1; }
}

.bento-icon {
  width: 48px;
  height: 48px;
  background-color: var(--sys-light-tertiary-container);
  color: var(--sys-light-tertiary);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
}

.bento-icon svg { width: 28px; height: 28px; }

.bento-card h3 {
  font-size: 24px;
  margin-bottom: 12px;
  color: var(--sys-light-on-surface);
}

.bento-card p {
  color: var(--sys-light-on-surface-variant);
}

/* FAQ */
.faq-wrap {
  max-width: 800px;
  margin: 0 auto;
}
.faq-item {
  background-color: #fff;
  margin-bottom: 16px;
  border-radius: var(--radius-lg);
  padding: 24px;
}
.faq-q {
  font-size: 18px;
  font-weight: 500;
  margin-bottom: 0;
  color: var(--sys-light-on-surface);
  cursor: pointer;
}
.faq-a {
  color: var(--sys-light-on-surface-variant);
  display: none;
 }
 .faq-item.open .faq-q {
  margin-bottom: 12px;
 }
 .faq-item.open .faq-a {
  display: block;
}

/* Download Cards */
.dl-card-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 24px;
  margin-top: 40px;
}
.dl-card {
  background: #fff;
  padding: 32px;
  border-radius: var(--radius-xl);
  text-align: center;
}
.dl-card .os-icon {
  width: 64px; height: 64px;
  margin: 0 auto 20px;
  color: var(--sys-light-primary);
}
.dl-card h4 {
  font-size: 20px;
  margin-bottom: 8px;
}
.dl-card p {
  font-size: 14px;
  color: var(--sys-light-on-surface-variant);
  margin-bottom: 24px;
}

/* Stats */
.stats-banner {
  background-color: var(--sys-light-on-surface);
  color: #fff;
  padding: 60px 24px;
  border-radius: var(--radius-xl);
  display: flex;
  justify-content: space-around;
  flex-wrap: wrap;
  gap: 32px;
  margin: var(--spacing-section) auto;
  max-width: 1200px;
}
.stat-box { text-align: center; }
.stat-num { font-size: 48px; font-weight: bold; color: var(--sys-light-tertiary-container); }
.stat-label { font-size: 16px; opacity: 0.8; }

/* Reviews */
.reviews {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}
.review-item {
  background: #fff;
  padding: 24px;
  border-radius: var(--radius-lg);
}
.stars { color: #fbbc04; margin-bottom: 12px; }

/* Article */
.article-content {
  max-width: 800px;
  margin: 0 auto;
  background: #fff;
  padding: 48px;
  border-radius: var(--radius-xl);
}
.article-content h2 { font-size: 28px; margin: 32px 0 16px; }
.article-content p { margin-bottom: 16px; color: var(--sys-light-on-surface-variant); }

/* Footer */
.site-footer {
  text-align: center;
  padding: 40px 24px;
  background-color: var(--sys-light-surface-variant);
  color: var(--sys-light-on-surface-variant);
  font-size: 14px;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}