/* Calculadora IGV - Fernando Gutierrez Mejia */
:root {
  --bg-dark: #0a0e17;
  --bg-card: #111827;
  --bg-card-hover: #1a2332;
  --accent: #22d3ee;
  --accent-dim: #06b6d4;
  --accent-glow: rgba(34, 211, 238, 0.25);
  --text: #f8fafc;
  --text-muted: #94a3b8;
  --border: #1e293b;
  --radius: 16px;
  --radius-sm: 10px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'DM Sans', system-ui, -apple-system, sans-serif;
  background: var(--bg-dark);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.6;
  position: relative;
  overflow-x: hidden;
}

/* Gradiente de fondo */
.bg-gradient {
  position: fixed;
  inset: 0;
  background: 
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(34, 211, 238, 0.12), transparent),
    radial-gradient(ellipse 60% 40% at 100% 50%, rgba(6, 182, 212, 0.08), transparent),
    radial-gradient(ellipse 60% 40% at 0% 80%, rgba(34, 211, 238, 0.06), transparent);
  pointer-events: none;
  z-index: 0;
}

.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
  position: relative;
  z-index: 1;
}

/* Header */
header {
  text-align: center;
  margin-bottom: 2.5rem;
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}

.logo-icon {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--accent);
  background: var(--accent-glow);
  padding: 0.35rem 0.6rem;
  border-radius: var(--radius-sm);
  letter-spacing: 0.05em;
}

header h1 {
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.02em;
}

.subtitle {
  color: var(--text-muted);
  font-size: 1rem;
}

.subtitle strong {
  color: var(--accent);
}

/* Flujo de uso */
.flow-section {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 2rem;
}

.flow-section h2 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1.25rem;
}

.flow-steps {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.flow-step {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1rem 0;
  border-bottom: 1px dashed var(--border);
}

.flow-step:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.flow-step:first-child {
  padding-top: 0;
}

.step-number {
  flex-shrink: 0;
  width: 2rem;
  height: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent);
  color: var(--bg-dark);
  font-family: 'JetBrains Mono', monospace;
  font-weight: 600;
  font-size: 0.875rem;
  border-radius: 50%;
}

.step-content {
  flex: 1;
}

.step-content strong {
  display: block;
  color: var(--text);
  font-size: 0.9375rem;
  margin-bottom: 0.25rem;
}

.step-content p {
  color: var(--text-muted);
  font-size: 0.8125rem;
  line-height: 1.5;
}

.step-arrow {
  color: var(--accent);
  opacity: 0.6;
  font-size: 1.25rem;
  margin-top: 0.25rem;
}

/* Calculator cards */
.calculator {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.card:hover {
  border-color: rgba(34, 211, 238, 0.3);
}

.card-featured {
  border-color: rgba(34, 211, 238, 0.25);
  box-shadow: 0 0 0 1px rgba(34, 211, 238, 0.1);
}

.card-badge {
  display: inline-block;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.6875rem;
  font-weight: 500;
  color: var(--accent);
  background: var(--accent-glow);
  padding: 0.25rem 0.5rem;
  border-radius: 6px;
  margin-bottom: 0.75rem;
  letter-spacing: 0.04em;
}

.card h2 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  color: var(--text);
}

.hint {
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.input-group {
  margin-bottom: 1.25rem;
}

.input-group label {
  display: block;
  font-size: 0.8125rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
  color: var(--text-muted);
}

.input-group input {
  width: 100%;
  padding: 0.875rem 1rem;
  font-size: 1.25rem;
  font-family: 'JetBrains Mono', monospace;
  font-weight: 500;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-dark);
  color: var(--text);
  transition: border-color 0.2s, box-shadow 0.2s;
}

.input-group input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.input-group input::placeholder {
  color: var(--text-muted);
  opacity: 0.5;
}

.input-group input[type="number"]::-webkit-inner-spin-button,
.input-group input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.input-group input[type="number"] {
  -moz-appearance: textfield;
  appearance: textfield;
}

.resultado {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
}

.result-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 1rem;
  background: var(--bg-dark);
  border-radius: var(--radius-sm);
}

.result-item.total {
  background: rgba(34, 211, 238, 0.08);
  border: 1px solid rgba(34, 211, 238, 0.3);
}

.result-item .label {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.result-item .valor {
  font-size: 1.25rem;
  font-weight: 600;
  font-family: 'JetBrains Mono', monospace;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

/* Footer */
footer {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
}

footer .small {
  font-size: 0.75rem;
  margin-top: 0.5rem;
  opacity: 0.7;
}

footer strong {
  color: var(--accent);
}

/* Responsive */
@media (min-width: 640px) {
  .flow-steps {
    flex-direction: row;
    flex-wrap: wrap;
  }
  
  .flow-step {
    flex: 1;
    min-width: 180px;
    flex-direction: column;
    align-items: flex-start;
    border-bottom: none;
    border-right: 1px dashed var(--border);
    padding: 0 1rem;
  }
  
  .flow-step:last-child {
    border-right: none;
    padding-right: 0;
  }
  
  .flow-step:first-child {
    padding-left: 0;
  }
  
  .step-arrow {
    display: none;
  }
}

@media (min-width: 700px) {
  .calculator {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }
}