/* ─── synthux Landing Page — Design System ─── */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

/* ─── Tokens ─── */
:root {
  --sx-blue: #007eff;
  --sx-blue-dim: rgba(0, 126, 255, 0.12);
  --sx-blue-glow: rgba(0, 126, 255, 0.25);
  --sx-bg-primary: #0a0a0c;
  --sx-bg-secondary: #111114;
  --sx-bg-card: rgba(255, 255, 255, 0.03);
  --sx-bg-card-hover: rgba(255, 255, 255, 0.06);
  --sx-text-primary: #ededf0;
  --sx-text-secondary: #a1a1aa;
  --sx-text-tertiary: #71717a;
  --sx-border: rgba(255, 255, 255, 0.08);
  --sx-border-hover: rgba(255, 255, 255, 0.14);
  --sx-radius: 16px;
  --sx-radius-sm: 10px;
  --sx-font: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --sx-max-width: 1120px;
  --sx-success: #22c55e;
}

/* ─── Reset ─── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--sx-font);
  background: var(--sx-bg-primary);
  color: var(--sx-text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

a { color: var(--sx-blue); text-decoration: none; transition: opacity 0.2s; }
a:hover { opacity: 0.85; }

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

/* ─── Layout ─── */
.container {
  max-width: var(--sx-max-width);
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 96px 0;
}

/* ─── Navigation ─── */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 16px 0;
  background: rgba(10, 10, 12, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--sx-border);
  transition: background 0.3s;
}

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

.nav-logo img {
  height: 22px;
  width: auto;
}

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

.nav-links a {
  font-size: 13px;
  font-weight: 500;
  color: var(--sx-text-secondary);
  transition: color 0.2s;
}

.nav-links a:hover { color: var(--sx-text-primary); opacity: 1; }

.nav-cta {
  padding: 8px 18px;
  background: var(--sx-blue);
  color: #fff !important;
  border-radius: 8px;
  font-weight: 600;
  font-size: 13px;
  transition: transform 0.15s, box-shadow 0.15s;
}

.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 20px var(--sx-blue-glow);
  opacity: 1;
}

.lang-btn {
  background: var(--sx-bg-card);
  border: 1px solid var(--sx-border);
  color: var(--sx-text-secondary);
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--sx-font);
  transition: all 0.2s;
}

.lang-btn:hover {
  background: var(--sx-bg-card-hover);
  color: var(--sx-text-primary);
}

/* ─── Hero ─── */
.hero {
  padding: 160px 0 96px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -200px;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 600px;
  background: radial-gradient(ellipse, var(--sx-blue-glow) 0%, transparent 70%);
  pointer-events: none;
  opacity: 0.4;
}

.hero-badges {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
  background: var(--sx-bg-card);
  border: 1px solid var(--sx-border);
  color: var(--sx-text-secondary);
}

.badge .dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--sx-success);
}

.hero h1 {
  font-size: clamp(36px, 6vw, 64px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -1.5px;
  margin-bottom: 20px;
  position: relative;
}

.hero-subtitle {
  font-size: clamp(16px, 2.2vw, 19px);
  color: var(--sx-text-secondary);
  max-width: 640px;
  margin: 0 auto 40px;
  line-height: 1.7;
}

.hero-ctas {
  display: flex;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  background: var(--sx-blue);
  color: #fff;
  border-radius: 12px;
  font-weight: 700;
  font-size: 15px;
  transition: transform 0.15s, box-shadow 0.15s;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 30px var(--sx-blue-glow);
  opacity: 1;
  color: #fff;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  background: var(--sx-bg-card);
  border: 1px solid var(--sx-border);
  color: var(--sx-text-primary);
  border-radius: 12px;
  font-weight: 700;
  font-size: 15px;
  transition: all 0.15s;
}

.btn-secondary:hover {
  background: var(--sx-bg-card-hover);
  border-color: var(--sx-border-hover);
  opacity: 1;
  color: var(--sx-text-primary);
}

/* ─── Section Headers ─── */
.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-header h2 {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  letter-spacing: -0.8px;
  margin-bottom: 12px;
}

.section-header p {
  color: var(--sx-text-secondary);
  font-size: 17px;
  max-width: 520px;
  margin: 0 auto;
}

/* ─── Features Grid ─── */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.feature-card {
  padding: 32px;
  background: var(--sx-bg-card);
  border: 1px solid var(--sx-border);
  border-radius: var(--sx-radius);
  transition: all 0.25s;
}

.feature-card:hover {
  background: var(--sx-bg-card-hover);
  border-color: var(--sx-border-hover);
  transform: translateY(-4px);
}

.feature-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--sx-blue-dim);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  margin-bottom: 18px;
}

.feature-card h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 8px;
}

.feature-card p {
  color: var(--sx-text-secondary);
  font-size: 14px;
  line-height: 1.6;
}

/* ─── How It Works ─── */
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.step {
  text-align: center;
  padding: 40px 28px;
  background: var(--sx-bg-card);
  border: 1px solid var(--sx-border);
  border-radius: var(--sx-radius);
  position: relative;
}

.step-number {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--sx-blue);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 20px;
  margin: 0 auto 20px;
}

.step h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 10px;
}

.step p {
  color: var(--sx-text-secondary);
  font-size: 14px;
}

/* ─── Screenshot ─── */
.screenshot-section {
  background: var(--sx-bg-secondary);
  border-top: 1px solid var(--sx-border);
  border-bottom: 1px solid var(--sx-border);
}

.screenshot-wrapper {
  max-width: 800px;
  margin: 0 auto;
  border-radius: var(--sx-radius);
  overflow: hidden;
  border: 1px solid var(--sx-border);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.screenshot-wrapper img {
  display: block;
  width: 100%;
}

/* ─── Privacy ─── */
.privacy-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-bottom: 32px;
}

.privacy-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 24px;
  background: var(--sx-bg-card);
  border: 1px solid var(--sx-border);
  border-radius: var(--sx-radius-sm);
}

.privacy-icon {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: rgba(34, 197, 94, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}

.privacy-item p {
  color: var(--sx-text-secondary);
  font-size: 14px;
  line-height: 1.6;
}

/* ─── Open Source ─── */
.oss-section {
  text-align: center;
}

.oss-section .oss-desc {
  color: var(--sx-text-secondary);
  font-size: 17px;
  max-width: 500px;
  margin: 0 auto 32px;
}

.oss-ctas {
  display: flex;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
}

/* ─── Footer ─── */
.footer {
  padding: 64px 0 32px;
  border-top: 1px solid var(--sx-border);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}

.footer-brand img {
  height: 20px;
  margin-bottom: 12px;
}

.footer-brand p {
  color: var(--sx-text-tertiary);
  font-size: 13px;
}

.footer-col h4 {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 16px;
  color: var(--sx-text-secondary);
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 10px;
}

.footer-col a {
  font-size: 13px;
  color: var(--sx-text-tertiary);
  transition: color 0.2s;
}

.footer-col a:hover { color: var(--sx-text-primary); opacity: 1; }

.footer-bottom {
  border-top: 1px solid var(--sx-border);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-bottom p {
  color: var(--sx-text-tertiary);
  font-size: 12px;
}

/* ─── Animations ─── */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ─── Responsive ─── */
@media (max-width: 900px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; max-width: 400px; margin: 0 auto; }
  .privacy-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
}

@media (max-width: 600px) {
  section { padding: 64px 0; }
  .hero { padding: 120px 0 64px; }
  .features-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .nav-links { gap: 16px; }
  .nav-links .nav-link-desktop { display: none; }
  .hero-ctas { flex-direction: column; align-items: center; }
  .btn-primary, .btn-secondary { width: 100%; max-width: 300px; justify-content: center; }
  .footer-bottom { flex-direction: column; gap: 12px; text-align: center; }
}