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

:root {
  --bg:       #0E1621;
  --bg-light: #17212B;
  --bg-card:  #1E2A36;
  --accent:   #2B9FEA;
  --accent-h: #1E8AD6;
  --text:     #E8ECF0;
  --text-dim: #8696A7;
  --radius:   12px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

/* ========== Nav ========== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(14, 22, 33, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.5px;
  color: var(--accent);
}

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

.nav-links a {
  font-size: 14px;
  color: var(--text-dim);
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--text);
}

/* ========== Hero ========== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 120px 32px 80px;
  background:
    radial-gradient(ellipse at 50% 0%, rgba(43,159,234,0.12) 0%, transparent 60%),
    var(--bg);
}

.hero-content {
  max-width: 680px;
}

.hero h1 {
  font-size: clamp(40px, 7vw, 72px);
  font-weight: 800;
  letter-spacing: -2px;
  line-height: 1.1;
  margin-bottom: 24px;
}

.hero-sub {
  font-size: 20px;
  color: var(--text-dim);
  margin-bottom: 48px;
  line-height: 1.5;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ========== Buttons ========== */
.btn {
  display: inline-block;
  padding: 14px 36px;
  border-radius: 50px;
  font-size: 15px;
  font-weight: 600;
  transition: all 0.2s;
  cursor: pointer;
}

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

.btn-primary:hover {
  background: var(--accent-h);
  transform: translateY(-1px);
}

.btn-ghost {
  border: 1px solid rgba(255,255,255,0.15);
  color: var(--text);
}

.btn-ghost:hover {
  border-color: rgba(255,255,255,0.3);
  background: rgba(255,255,255,0.04);
}

/* ========== Sections ========== */
.section {
  padding: 120px 32px;
  max-width: 1200px;
  margin: 0 auto;
}

.section-dark {
  max-width: 100%;
  background: var(--bg-light);
}

.section-dark > * {
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
}

.section-title {
  font-size: 36px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 64px;
  letter-spacing: -1px;
}

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

.feature-card {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 36px 32px;
  border: 1px solid rgba(255,255,255,0.05);
  transition: transform 0.2s, border-color 0.2s;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: rgba(43,159,234,0.3);
}

.feature-icon {
  font-size: 32px;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 10px;
}

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

/* ========== Security ========== */
.security-content {
  max-width: 720px;
  margin: 0 auto;
}

.security-item {
  padding: 32px 0;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.security-item:last-child {
  border-bottom: none;
}

.security-item h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 8px;
}

.security-item p {
  color: var(--text-dim);
  font-size: 15px;
}

/* ========== Download ========== */
.download-sub {
  text-align: center;
  color: var(--text-dim);
  font-size: 16px;
  margin-top: -48px;
  margin-bottom: 56px;
}

.download-grid {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
}

.download-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  width: 140px;
  padding: 32px 24px;
  background: var(--bg-card);
  border-radius: var(--radius);
  border: 1px solid rgba(255,255,255,0.05);
  transition: all 0.2s;
}

.download-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.download-icon {
  font-size: 36px;
}

.download-platform {
  font-size: 14px;
  font-weight: 600;
}

/* ========== Footer ========== */
.footer {
  border-top: 1px solid rgba(255,255,255,0.06);
  padding: 48px 32px;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 24px;
}

.footer-brand {
  font-size: 18px;
  font-weight: 700;
  color: var(--accent);
}

.footer-links {
  display: flex;
  gap: 24px;
}

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

.footer-links a:hover {
  color: var(--text);
}

.footer-copy {
  font-size: 12px;
  color: var(--text-dim);
}

/* ========== 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: 768px) {
  .nav-links {
    gap: 20px;
  }

  .hero {
    padding: 100px 24px 60px;
  }

  .section {
    padding: 80px 24px;
  }

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

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
}