/* === Variables & Base Reset === */
:root {
  --primary-color: #1a73e8;
  --primary-hover: #1557b0;
  --secondary-color: #5f6368;
  --bg-color: #f8f9fa;
  --text-color: #202124;
  --border-color: #dadce0;
  --white: #ffffff;
  --shadow: 0 4px 6px rgba(0,0,0,0.1);
  --shadow-hover: 0 10px 15px rgba(0,0,0,0.15);
  --transition: all 0.3s ease;
  --nav-height: 64px;
}

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

body {
  font-family: 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color: var(--text-color);
  background-color: var(--white);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

ul {
  list-style: none;
}

/* === Layout & Utilities === */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 80px 0;
}

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

.section-title {
  text-align: center;
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: #202124;
}

.section-subtitle {
  text-align: center;
  font-size: 1.25rem;
  color: var(--secondary-color);
  margin-bottom: 48px;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

/* === Buttons === */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  font-size: 1.1rem;
  font-weight: 600;
  border-radius: 24px;
  cursor: pointer;
  border: none;
  transition: var(--transition);
}

.btn-primary {
  background-color: var(--primary-color);
  color: var(--white);
  box-shadow: 0 2px 4px rgba(26, 115, 232, 0.3);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  box-shadow: 0 4px 8px rgba(26, 115, 232, 0.4);
}

.btn-primary:disabled {
  background-color: #a0c2f9;
  cursor: not-allowed;
  box-shadow: none;
}

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

.btn-outline:hover {
  background-color: #f1f3f4;
}

/* === Navigation === */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--white);
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
  height: var(--nav-height);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 100%;
}

.nav-logo {
  display: flex;
  align-items: center;
  font-size: 1.25rem;
  font-weight: 600;
  color: #5f6368;
}

.nav-logo svg {
  width: 32px;
  height: 32px;
  margin-right: 12px;
}

.nav-links {
  display: flex;
  gap: 32px;
}

.nav-link {
  font-size: 1rem;
  font-weight: 500;
  color: var(--secondary-color);
  padding: 8px 0;
  position: relative;
  transition: color 0.3s;
}

.nav-link:hover {
  color: var(--primary-color);
}

.nav-link.active {
  color: var(--primary-color);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background-color: var(--primary-color);
  border-radius: 3px 3px 0 0;
}

/* === Hero Section === */
.hero {
  padding: 120px 0 80px;
  text-align: center;
}

.hero-title {
  font-size: 4rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 24px;
  background: linear-gradient(90deg, #4285f4, #ea4335, #fbbc04, #34a853);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.5rem;
  color: var(--secondary-color);
  margin-bottom: 40px;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.hero-actions {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.hero-disclaimer {
  font-size: 0.875rem;
  color: #80868b;
  margin-top: 12px;
}

/* === Features Grid === */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 32px;
  margin-top: 48px;
}

.feature-card {
  background: var(--white);
  padding: 32px;
  border-radius: 16px;
  box-shadow: var(--shadow);
  transition: var(--transition);
  text-align: left;
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
}

.feature-icon {
  width: 48px;
  height: 48px;
  background-color: #e8f0fe;
  color: var(--primary-color);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
}

.feature-icon svg {
  width: 24px;
  height: 24px;
}

.feature-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--text-color);
}

.feature-desc {
  color: var(--secondary-color);
  font-size: 1rem;
}

/* === Detailed Features (Alternating) === */
.detail-row {
  display: flex;
  align-items: center;
  gap: 64px;
  margin-bottom: 80px;
}

.detail-row:nth-child(even) {
  flex-direction: row-reverse;
}

.detail-content {
  flex: 1;
}

.detail-image {
  flex: 1;
  background-color: var(--bg-color);
  border-radius: 16px;
  padding: 40px;
  display: flex;
  justify-content: center;
  align-items: center;
}

.detail-image svg {
  width: 100%;
  max-width: 400px;
  height: auto;
}

/* === Platforms Section === */
.platforms-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 24px;
}

.platform-card {
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 24px;
  text-align: center;
  background: var(--white);
}

.platform-icon svg {
  width: 40px;
  height: 40px;
  margin-bottom: 16px;
  fill: #5f6368;
}

.platform-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.platform-req {
  font-size: 0.875rem;
  color: var(--secondary-color);
  margin-bottom: 24px;
}

/* === Stats Section === */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}

.stat-item {
  padding: 32px 16px;
}

.stat-num {
  font-size: 3rem;
  font-weight: 700;
  color: var(--primary-color);
  margin-bottom: 8px;
}

.stat-label {
  font-size: 1.1rem;
  color: var(--secondary-color);
}

/* === Testimonials === */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.review-card {
  background: var(--bg-color);
  padding: 24px;
  border-radius: 12px;
}

.review-stars {
  color: #fbbc04;
  margin-bottom: 12px;
}

.review-stars svg {
  width: 18px;
  height: 18px;
}

.review-text {
  font-style: italic;
  margin-bottom: 16px;
  color: #3c4043;
}

.review-author {
  font-weight: 600;
  font-size: 0.9rem;
}

/* === FAQ Section === */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  border-bottom: 1px solid var(--border-color);
  padding: 24px 0;
}

.faq-q {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--text-color);
}

.faq-a {
  color: var(--secondary-color);
  line-height: 1.7;
}

/* === Table === */
.compare-table {
  width: 100%;
  max-width: 800px;
  margin: 0 auto;
  border-collapse: collapse;
  background: var(--white);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.compare-table th, .compare-table td {
  padding: 16px 24px;
  text-align: center;
  border-bottom: 1px solid var(--border-color);
}

.compare-table th:first-child, .compare-table td:first-child {
  text-align: left;
}

.compare-table th {
  background-color: var(--bg-color);
  font-weight: 600;
}

.compare-table svg {
  width: 20px;
  height: 20px;
}

.icon-check { color: #34a853; }
.icon-cross { color: #ea4335; }

/* === Footer === */
.footer {
  background-color: var(--bg-color);
  border-top: 1px solid var(--border-color);
  padding: 40px 0;
  text-align: center;
  color: var(--secondary-color);
  font-size: 0.875rem;
}

.footer-safety {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-bottom: 16px;
  color: #34a853;
  font-weight: 600;
}

.footer-safety svg {
  width: 20px;
  height: 20px;
}

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

/* === Responsive === */
@media (max-width: 768px) {
  .hero-title { font-size: 2.5rem; }
  .detail-row, .detail-row:nth-child(even) { flex-direction: column; gap: 32px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .nav-links { gap: 16px; }
}

@media (max-width: 480px) {
  .stats-grid { grid-template-columns: 1fr; }
  .nav-links { display: none; /* simple mobile nav override could be added */ }
}

/* === Specific Page Styles === */
/* Download Page */
.dl-hero {
  background: linear-gradient(135deg, #e8f0fe 0%, #fce8e6 100%);
  border-radius: 24px;
  padding: 60px 40px;
  text-align: center;
  margin-top: 40px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.05);
}

.dl-hero-content {
  max-width: 600px;
  margin: 0 auto;
}

.dl-main-btn {
  font-size: 1.25rem;
  padding: 16px 40px;
  margin: 24px 0 16px;
}

.dl-steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 24px;
  margin-top: 40px;
  text-align: center;
}

.step-number {
  width: 40px;
  height: 40px;
  background: var(--primary-color);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  font-weight: bold;
  margin: 0 auto 16px;
}

.system-req-list {
  background: var(--white);
  border-radius: 12px;
  padding: 32px;
  box-shadow: var(--shadow);
}

.system-req-list h3 {
  margin-bottom: 16px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 8px;
}

.system-req-list ul {
  list-style: disc;
  padding-left: 20px;
  margin-bottom: 24px;
}

.system-req-list ul li {
  margin-bottom: 8px;
}

/* SEO Page */
.seo-article {
  max-width: 800px;
  margin: 0 auto;
}

.seo-article h2 {
  font-size: 2rem;
  margin: 40px 0 20px;
  color: var(--text-color);
}

.seo-article p {
  font-size: 1.1rem;
  line-height: 1.8;
  margin-bottom: 24px;
  color: #3c4043;
}

.seo-cta {
  text-align: center;
  margin: 60px 0;
  padding: 40px;
  background: #e8f0fe;
  border-radius: 16px;
}