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

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: #0b0f19;
  color: #e2e8f0;
  line-height: 1.6;
}

/* Header */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 8%;
  background: rgba(11, 15, 25, 0.9);
  backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.brand-name {
  font-weight: 800;
  font-size: 1.2rem;
}

.highlight {
  color: #00ff88;
}

nav {
  display: flex;
  gap: 20px;
  align-items: center;
}

.nav-link {
  color: #94a3b8;
  text-decoration: none;
  font-size: 0.95rem;
}

.nav-link:hover {
  color: #00ff88;
}

.btn-nav {
  padding: 8px 16px;
  border: 1px solid #00ff88;
  border-radius: 6px;
  color: #00ff88;
}

/* Hero Section */
.hero {
  text-align: center;
  padding: 50px 20px;
  max-width: 800px;
  margin: 0 auto;
}

.badge-tag {
  display: inline-block;
  background: rgba(0, 255, 136, 0.1);
  color: #00ff88;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  margin-bottom: 15px;
  border: 1px solid rgba(0, 255, 136, 0.2);
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 15px;
}

.text-gradient {
  background: linear-gradient(135deg, #00ff88 0%, #00d4ff 100%);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.intro {
  color: #94a3b8;
  font-size: 1.1rem;
}

/* Sección Interactiva */
.interactive-section {
  max-width: 1100px;
  margin: 0 auto 50px;
  padding: 0 20px;
}

.section-title {
  text-align: center;
  margin-bottom: 30px;
}

.section-title h2 {
  font-size: 1.8rem;
  color: #ffffff;
}

.section-title p {
  color: #94a3b8;
}

.interactive-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.interactive-card {
  background: #111827;
  border: 1px solid rgba(0, 255, 136, 0.3);
  border-radius: 12px;
  padding: 24px;
  position: relative;
}

.card-badge {
  position: absolute;
  top: 15px;
  right: 15px;
  background: rgba(0, 255, 136, 0.1);
  color: #00ff88;
  font-size: 0.65rem;
  font-weight: 800;
  padding: 2px 8px;
  border-radius: 4px;
}

.card-subtitle {
  color: #94a3b8;
  font-size: 0.85rem;
  margin-bottom: 20px;
}

.calc-form {
  display: flex;
  flex-direction: column;
  gap: 15px;
}

.input-group {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: #0b0f19;
  border: 1px solid rgba(255, 255, 255, 0.1);
  padding: 10px 14px;
  border-radius: 8px;
}

.input-group label {
  font-size: 0.85rem;
  color: #cbd5e1;
}

.input-group input {
  background: transparent;
  border: none;
  color: #00ff88;
  font-weight: 700;
  font-size: 1.1rem;
  text-align: right;
  width: 100px;
  outline: none;
}

.input-group .unit {
  color: #64748b;
  margin-left: 8px;
}

.calc-results {
  margin-top: 10px;
  padding-top: 12px;
  border-top: 1px dashed rgba(255, 255, 255, 0.1);
  display: flex;
  justify-content: space-between;
  color: #94a3b8;
}

/* Simulador LED */
.sim-controls {
  margin-bottom: 20px;
}

.sim-controls label {
  font-size: 0.85rem;
  color: #cbd5e1;
  display: block;
  margin-bottom: 8px;
}

.sim-controls input[type="range"] {
  width: 100%;
  accent-color: #00ff88;
}

.circuit-visual {
  display: flex;
  align-items: center;
  justify-content: space-around;
  background: #0b0f19;
  padding: 20px 10px;
  border-radius: 8px;
  margin-bottom: 15px;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.wire-line {
  height: 2px;
  background: #00ff88;
  flex: 1;
  margin: 0 10px;
}

.led-bulb {
  font-size: 1.8rem;
}

.sim-status {
  padding: 10px;
  border-radius: 6px;
  border: 1px solid #00ff88;
  background: rgba(0, 0, 0, 0.2);
  font-size: 0.85rem;
  text-align: center;
  color: #00ff88;
}

/* Grid de Cards */
.grid-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
  max-width: 1100px;
  margin: 0 auto 60px;
  padding: 0 20px;
}

.card {
  background: #111827;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 12px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 15px;
}

.card-id {
  font-size: 0.75rem;
  color: #64748b;
  font-family: monospace;
}

.card-icon {
  font-size: 1.5rem;
}

.card h3 {
  color: #f8fafc;
  font-size: 1.2rem;
  margin-bottom: 8px;
}

.card p {
  color: #94a3b8;
  font-size: 0.9rem;
  margin-bottom: 20px;
}

.btn-card {
  background: transparent;
  color: #00ff88;
  border: none;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
}

/* Footer */
footer {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 30px 20px;
  text-align: center;
  background: #080c14;
  color: #64748b;
  font-size: 0.9rem;
}

footer strong {
  color: #cbd5e1;
}