:root {
  --bg-color: #fdfcf8;
  --surface: #ffffff;
  --surface-alt: #f3f0e7;
  --text-main: #1e293b;
  --text-sub: #475569;
  --terra: #ca5c3b;
  --terra-hover: #b45133;
  --sunset: #f97316;
  --navy: #0f172a;
  --border: #e2e8f0;
  --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.05);
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 8px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

body {
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.6;
}

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

button {
  cursor: pointer;
  border: none;
  background: none;
  font-size: 1rem;
}

/* Nav */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(253, 252, 248, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 2rem;
}

.nav-brand {
  font-weight: 800;
  font-size: 1.5rem;
  color: var(--navy);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.nav-brand svg {
  width: 32px;
  height: 32px;
  color: var(--terra);
}

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-links a {
  font-weight: 600;
  color: var(--text-sub);
  transition: color 0.2s;
  padding: 0.5rem 1rem;
  border-radius: 999px;
}

.nav-links a:hover {
  color: var(--terra);
  background: var(--surface-alt);
}

.nav-links a.active {
  color: #fff;
  background: var(--terra);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 1.5rem;
  border-radius: 999px;
  font-weight: 700;
  transition: all 0.2s;
}

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

.btn-terra:hover {
  background: var(--terra-hover);
  transform: translateY(-2px);
}

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

.btn-outline:hover {
  background: var(--terra);
  color: #fff;
}

/* Layout */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 4rem 2rem;
}

.section-title {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--navy);
  margin-bottom: 1rem;
  text-align: center;
}

.section-desc {
  font-size: 1.125rem;
  color: var(--text-sub);
  text-align: center;
  max-width: 600px;
  margin: 0 auto 3rem;
}

/* Hero */
.hero {
  text-align: center;
  padding: 6rem 2rem;
  background: radial-gradient(circle at 50% 0%, var(--surface-alt) 0%, var(--bg-color) 70%);
}

.hero-tag {
  display: inline-block;
  padding: 0.5rem 1rem;
  background: rgba(202, 92, 59, 0.1);
  color: var(--terra);
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.875rem;
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: 4rem;
  font-weight: 900;
  color: var(--navy);
  line-height: 1.1;
  margin-bottom: 1.5rem;
}

.hero-title span {
  color: var(--terra);
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-sub);
  max-width: 700px;
  margin: 0 auto 2.5rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.feature-card {
  background: var(--surface);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s, box-shadow 0.3s;
  border: 1px solid var(--border);
}

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

.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(249, 115, 22, 0.1);
  color: var(--sunset);
  margin-bottom: 1.5rem;
}

.feature-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--navy);
}

/* Platform Downloads */
.platforms-wrapper {
  background: var(--surface-alt);
  border-radius: var(--radius-lg);
  padding: 4rem;
  margin: 4rem 0;
}

.platforms-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}

.platform-card {
  background: var(--surface);
  border-radius: var(--radius-md);
  padding: 2rem;
  text-align: center;
  border: 1px solid var(--border);
}

.platform-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 1rem;
  color: var(--navy);
}

.platform-name {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.platform-desc {
  font-size: 0.875rem;
  color: var(--text-sub);
  margin-bottom: 1.5rem;
}

/* Deep Dive */
.deep-dive {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
  margin: 6rem 0;
}

.deep-dive.reverse {
  direction: rtl;
}

.deep-dive.reverse > * {
  direction: ltr;
}

.dive-content h3 {
  font-size: 2rem;
  font-weight: 800;
  color: var(--navy);
  margin-bottom: 1rem;
}

.dive-content p {
  color: var(--text-sub);
  font-size: 1.125rem;
  margin-bottom: 1.5rem;
}

.dive-visual {
  background: var(--surface-alt);
  border-radius: var(--radius-lg);
  padding: 3rem;
  text-align: center;
  display: flex;
  justify-content: center;
}

.dive-visual svg {
  width: 100%;
  max-width: 300px;
  height: auto;
  color: var(--terra);
}

/* Reviews */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.review-card {
  background: var(--surface);
  border-radius: var(--radius-md);
  padding: 2rem;
  border: 1px solid var(--border);
}

.review-stars {
  color: #fbbf24;
  margin-bottom: 1rem;
}

.review-text {
  font-style: italic;
  color: var(--text-sub);
  margin-bottom: 1.5rem;
}

.review-author {
  font-weight: 700;
  color: var(--navy);
}

/* Stats */
.stats-banner {
  background: var(--navy);
  color: #fff;
  border-radius: var(--radius-lg);
  padding: 4rem;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  text-align: center;
  gap: 2rem;
}

.stat-num {
  font-size: 3rem;
  font-weight: 900;
  color: var(--sunset);
  margin-bottom: 0.5rem;
}

.stat-label {
  font-size: 1.125rem;
  font-weight: 600;
  opacity: 0.9;
}

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

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

.faq-q {
  padding: 1.5rem 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 700;
  font-size: 1.125rem;
  cursor: pointer;
  color: var(--navy);
}

.faq-a {
  padding: 0 0 1.5rem;
  color: var(--text-sub);
  display: none;
}

.faq-item.active .faq-a {
  display: block;
}

.faq-icon {
  transition: transform 0.3s;
}

.faq-item.active .faq-icon {
  transform: rotate(45deg);
}

/* Table */
.comparison {
  overflow-x: auto;
  margin: 4rem 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  background: var(--surface);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

th, td {
  padding: 1.5rem;
  text-align: center;
  border-bottom: 1px solid var(--border);
}

th {
  background: var(--surface-alt);
  font-weight: 700;
  color: var(--navy);
}

th:first-child, td:first-child {
  text-align: left;
  font-weight: 600;
}

.highlight-col {
  background: rgba(202, 92, 59, 0.05);
}

/* Download Page Specific */
.dl-hero {
  padding: 4rem 2rem;
  text-align: center;
}

.dl-main-card {
  max-width: 800px;
  margin: 0 auto 4rem;
  background: var(--surface);
  border-radius: var(--radius-lg);
  padding: 4rem;
  box-shadow: var(--shadow-md);
  border: 2px solid var(--terra);
}

.dl-main-icon {
  width: 80px;
  height: 80px;
  color: var(--terra);
  margin-bottom: 1.5rem;
}

.dl-meta {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin: 2rem 0;
  color: var(--text-sub);
}

.guide-steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.step-card {
  background: var(--surface);
  padding: 2rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  position: relative;
}

.step-num {
  position: absolute;
  top: -15px;
  left: 20px;
  width: 30px;
  height: 30px;
  background: var(--terra);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
}

.ver-list {
  max-width: 800px;
  margin: 0 auto;
}

.ver-item {
  display: flex;
  gap: 2rem;
  padding: 2rem 0;
  border-bottom: 1px solid var(--border);
}

.ver-date {
  font-weight: 700;
  color: var(--terra);
  min-width: 120px;
}

/* Article Page Specific */
.article-layout {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 4rem;
  max-width: 1200px;
  margin: 0 auto;
  padding: 4rem 2rem;
}

.article-body h2 {
  font-size: 2rem;
  color: var(--navy);
  margin: 3rem 0 1.5rem;
}

.article-body p {
  margin-bottom: 1.5rem;
  font-size: 1.125rem;
}

.sidebar {
  position: sticky;
  top: 100px;
}

.sidebar-box {
  background: var(--surface);
  padding: 2rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  margin-bottom: 2rem;
}

.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2rem;
}

.tag {
  background: var(--surface-alt);
  padding: 0.5rem 1rem;
  border-radius: 999px;
  font-size: 0.875rem;
  color: var(--text-sub);
}

/* Footer */
.footer {
  background: var(--navy);
  color: #fff;
  padding: 4rem 2rem 2rem;
  text-align: center;
  margin-top: 4rem;
}

.security-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(34, 197, 94, 0.2);
  color: #4ade80;
  padding: 0.75rem 1.5rem;
  border-radius: 999px;
  font-weight: 600;
  margin-bottom: 2rem;
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .article-layout { grid-template-columns: 1fr; }
  .deep-dive { grid-template-columns: 1fr; }
  .stats-banner { grid-template-columns: 1fr 1fr; }
  .hero-title { font-size: 2.5rem; }
}

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