/* =========================
   VARIABLES
========================= */
:root {
  --primary: #1e3a8a;
  --primary-light: #3b82f6;
  --secondary: #0f172a;
  --bg: #f4f6fb;
  --card-bg: #ffffff;
  --text: #111827;
  --muted: #6b7280;
  --border: #e5e7eb;
  --radius: 16px;
  --shadow: 0 10px 30px rgba(0,0,0,.08);
}

/* =========================
   BASE
========================= */
body {
  background: var(--bg);
  color: var(--text);
  font-family: "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.6;
}

/* =========================
   HERO
========================= */
.hero-facturador {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 50px;
  align-items: center;
  padding: 90px 8%;
  background: linear-gradient(135deg, #eef2ff, #f8fafc);
}

.hero-content h1 {
  font-size: 48px;
  font-weight: 800;
  color: var(--secondary);
  margin-bottom: 15px;
}

.hero-subtitle {
  font-size: 18px;
  color: var(--muted);
  max-width: 520px;
  margin-bottom: 30px;
}

.hero-buttons {
  display: flex;
  gap: 15px;
  flex-wrap: wrap;
}

.hero-image img {
  max-width: 100%;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

/* =========================
   BOTONES
========================= */
.btn-primary,
.btn-secondary,
.btn-download {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 26px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 15px;
  text-decoration: none;
  transition: all .25s ease;
}

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

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

.btn-secondary {
  background: #fff;
  color: var(--primary);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: #f1f5ff;
}

.btn-download {
  background: linear-gradient(135deg, #16a34a, #22c55e);
  color: #fff;
  box-shadow: 0 10px 20px rgba(34,197,94,.35);
}

.btn-download:hover {
  transform: translateY(-2px);
}

/* =========================
   FEATURES
========================= */
.features-section {
  padding: 80px 8%;
  text-align: center;
}

.features-section h2 {
  font-size: 36px;
  font-weight: 800;
  margin-bottom: 15px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 25px;
  margin-top: 40px;
}

.feature-card {
  background: var(--card-bg);
  padding: 24px 22px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  font-size: 16px;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  transition: transform .25s ease;
}

.feature-card:hover {
  transform: translateY(-6px);
}

/* =========================
   USE CASES
========================= */
.use-cases {
  padding: 70px 8%;
  background: #fff;
}

.use-cases h2 {
  font-size: 32px;
  font-weight: 800;
  margin-bottom: 25px;
}

.use-cases ul {
  list-style: none;
  padding: 0;
  max-width: 500px;
}

.use-cases li {
  font-size: 17px;
  margin-bottom: 12px;
  color: var(--text);
}

/* =========================
   DOWNLOAD
========================= */
.download-section {
  padding: 80px 8%;
  text-align: center;
  background: linear-gradient(135deg, #020617, #020617);
  color: #fff;
}

.download-section h2 {
  font-size: 36px;
  font-weight: 800;
  margin-bottom: 15px;
}

.download-section p {
  color: #cbd5f5;
  max-width: 600px;
  margin: 0 auto 30px;
}

.download-note {
  margin-top: 15px;
  font-size: 14px;
  opacity: .75;
}

/* =========================
   CTA FINAL
========================= */
.cta-section {
  padding: 70px 8%;
  text-align: center;
  background: #f8fafc;
}

.cta-section h2 {
  font-size: 32px;
  font-weight: 800;
  margin-bottom: 10px;
}

.cta-section p {
  color: var(--muted);
  margin-bottom: 25px;
}

/* =========================
   RESPONSIVE
========================= */
@media (max-width: 900px) {
  .hero-facturador {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-buttons {
    justify-content: center;
  }

  .hero-content h1 {
    font-size: 38px;
  }
}

@media (max-width: 480px) {
  .hero-content h1 {
    font-size: 32px;
  }

  .features-section h2,
  .download-section h2 {
    font-size: 28px;
  }
}

/* =========================
   PREVIEW / CAROUSEL
========================= */
.preview-section {
  padding: 80px 8%;
  background: #fff;
  text-align: center;
}

.preview-section h2 {
  font-size: 36px;
  font-weight: 800;
  margin-bottom: 10px;
}

.preview-subtitle {
  color: var(--muted);
  margin-bottom: 40px;
}

.preview-carousel {
  position: relative;
  max-width: 1000px;
  margin: 0 auto;
  overflow: hidden;
  border-radius: 16px;
  box-shadow: var(--shadow);
  background: #000;
}

.preview-track {
  display: flex;
  transition: transform .4s ease;
}

.preview-track img {
  width: 100%;
  flex-shrink: 0;
  object-fit: contain;
  background: #000;
}

/* BOTONES */
.preview-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(0,0,0,.55);
  color: #fff;
  border: none;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  font-size: 26px;
  cursor: pointer;
  z-index: 10;
  transition: background .2s ease;
}

.preview-btn:hover {
  background: rgba(0,0,0,.85);
}

.preview-btn.prev { left: 12px; }
.preview-btn.next { right: 12px; }

/* RESPONSIVE */
@media (max-width: 768px) {
  .preview-section h2 {
    font-size: 28px;
  }
}