:root {
  --bg-dark: #121212;
  --bg-light: #1E1E1E;
  --card-bg: #2A2A2A;
  --primary-accent: #1DB954; /* Un verde vibrante como Spotify */
  --text-primary: #FFFFFF;
  --text-secondary: #B3B3B3;
  --card-border: #404040;
  --shadow-color: rgba(0, 0, 0, 0.5);
}

body {
  margin: 0;
  font-family: 'Poppins', sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-primary);
  display: flex;
  justify-content: center;
  padding: 2rem;
}

.container {
  width: 100%;
  max-width: 1200px;
}

/* --- Encabezado --- */
.main-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: var(--bg-light);
  padding: 1.5rem 2rem;
  border-radius: 12px;
  border: 1px solid var(--card-border);
  margin-bottom: 2rem;
}

.main-header h1 {
  margin: 0;
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary-accent);
}

.subtitle {
  margin: 0.25rem 0 0;
  color: var(--text-secondary);
  font-weight: 300;
}

.cta-button {
  background-color: var(--primary-accent);
  color: var(--text-primary);
  text-decoration: none;
  padding: 0.8rem 1.5rem;
  border-radius: 50px;
  font-weight: 600;
  transition: background-color 0.3s ease, transform 0.2s ease;
  white-space: nowrap;
}

.cta-button:hover {
  background-color: #1ed760;
  transform: scale(1.05);
}

/* --- Títulos de Sección --- */
.section-title {
  font-size: 1.8rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 2rem;
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--primary-accent);
  display: inline-block;
}

/* --- Estructura de Tarjetas (Cards) --- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
  margin-bottom: 2rem;
}

.card {
  background-color: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 8px 24px var(--shadow-color);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  display: flex;
  flex-direction: column;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 32px var(--shadow-color);
}

.card-header {
  padding: 1rem 1.5rem;
  background-color: rgba(0,0,0,0.2);
}

.card-header h3 {
  margin: 0;
  font-size: 1.25rem;
  font-weight: 600;
}

.card-body {
    flex-grow: 1;
}

.card-body img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
}

.card.full-width {
  grid-column: 1 / -1;
  margin-bottom: 2rem;
}


/* --- Grid de Métricas --- */
.card-grid-metrics {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    text-align: center;
    margin-bottom: 2rem;
}

.card-metric {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--card-border);
    transition: transform 0.3s ease;
}
.card-metric:hover{
    transform: translateY(-5px);
}

.card-metric h4 {
    margin: 0 0 0.5rem 0;
    font-size: 1.1rem;
    font-weight: 400;
    color: var(--text-secondary);
}

.metric-value {
    margin: 0;
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-accent);
}

.metric-label {
    margin: 0;
    font-size: 1rem;
    font-weight: 300;
    color: var(--text-secondary);
}

/* --- Tarjeta de Conclusiones --- */
.card-conclusion {
    background-color: var(--bg-light);
    border-left: 5px solid var(--primary-accent);
    padding: 1.5rem 2rem;
    border-radius: 8px;
    margin-top: 1rem;
}

.card-conclusion h4 {
    margin-top: 0;
    font-size: 1.4rem;
    color: var(--text-primary);
}

.card-conclusion p {
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text-secondary);
}

.card-conclusion code {
    background-color: var(--card-bg);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-family: monospace;
}

/* --- Pie de Página --- */
.main-footer {
  text-align: center;
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--card-border);
  color: var(--text-secondary);
  font-weight: 300;
}

/* --- Responsividad para móviles --- */
@media (max-width: 768px) {
  .main-header {
    flex-direction: column;
    text-align: center;
    gap: 1.5rem;
  }
  .card-grid, .card-grid-metrics {
    grid-template-columns: 1fr;
  }
}