:root {
  --ink: #1d1d1f;
  --muted: #5f6368;
  --line: #d9dce1;
  --bg: #f4f5f7;
  --card: #ffffff;
  --accent: #0b57d0;
  --sale: #c5221f;
  --ok: #137333;
  --warn: #b3261e;
  --star: #e8a600;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 17px;
  line-height: 1.5;
}

main {
  max-width: 680px;
  margin: 0 auto;
  padding: 24px 16px 48px;
}

h1 { font-size: 1.45rem; line-height: 1.25; margin: 0 0 12px; }
h2 { font-size: 1.15rem; margin: 0 0 8px; }
p { margin: 0 0 12px; }
.small { font-size: .85rem; color: var(--muted); }

.panel {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 20px;
}

.progress {
  height: 6px;
  background: var(--line);
  border-radius: 3px;
  margin-bottom: 16px;
  overflow: hidden;
}
.progress > div { height: 100%; background: var(--accent); transition: width .3s; }

button.primary {
  display: block;
  width: 100%;
  margin-top: 20px;
  padding: 14px 18px;
  font-size: 1rem;
  font-weight: 600;
  color: #fff;
  background: var(--accent);
  border: 0;
  border-radius: 10px;
  cursor: pointer;
}
button.primary:disabled { background: #9aa0a6; cursor: not-allowed; }

/* Tarjeta de producto (estímulo) */
.product {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 18px 20px;
}
.product .brand {
  font-weight: 800;
  letter-spacing: .12em;
  font-size: 1.05rem;
}
.product .badges { margin: 6px 0 8px; }
.badge {
  display: inline-block;
  font-size: .75rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 4px;
  background: #e8f0fe;
  color: var(--accent);
  margin-right: 6px;
}
.product .title { font-size: 1.1rem; font-weight: 600; margin: 4px 0; }
.product .meta { font-size: .8rem; color: var(--muted); }
.product .stars { font-size: .9rem; margin: 4px 0 12px; }
.product .stars span { color: var(--star); letter-spacing: 1px; }

.metric {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 10px 0;
  margin-bottom: 12px;
}
.metric .row { display: flex; justify-content: space-between; align-items: baseline; }
.metric .lbl { font-size: .85rem; color: var(--muted); }
.metric .strike { text-decoration: line-through; color: var(--muted); }
.metric .delta { color: var(--sale); font-weight: 600; }
.metric .big { font-size: 1.6rem; font-weight: 700; }
.metric .tag {
  display: inline-block;
  margin-top: 6px;
  background: var(--sale);
  color: #fff;
  font-weight: 700;
  font-size: .8rem;
  padding: 2px 8px;
  border-radius: 4px;
}

.features { list-style: none; padding: 0; margin: 0 0 10px; }
.features li {
  display: flex;
  gap: 10px;
  padding: 7px 0;
  font-size: .93rem;
  border-bottom: 1px dashed var(--line);
}
.features li:last-child { border-bottom: 0; }
.features .k { font-weight: 600; flex: 0 0 118px; }
.features .hi .mark { color: var(--ok); }
.features .lo .mark { color: var(--warn); }
.features .mark { font-weight: 700; }

/* Escala de confianza */
.question { margin-top: 18px; }
.slider-wrap { margin-top: 10px; }
input[type=range] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 32px;
  background: transparent;
  cursor: pointer;
}
input[type=range]::-webkit-slider-runnable-track { height: 8px; background: var(--line); border-radius: 4px; }
input[type=range]::-moz-range-track { height: 8px; background: var(--line); border-radius: 4px; }
input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 24px; height: 24px; margin-top: -8px;
  border-radius: 50%; background: var(--accent); border: 2px solid #fff;
}
input[type=range]::-moz-range-thumb { width: 22px; height: 22px; border-radius: 50%; background: var(--accent); border: 2px solid #fff; }
input[type=range].untouched::-webkit-slider-thumb { opacity: 0; }
input[type=range].untouched::-moz-range-thumb { opacity: 0; }
.slider-ends { display: flex; justify-content: space-between; font-size: .8rem; color: var(--muted); }
.slider-value { text-align: center; font-weight: 600; min-height: 1.5em; }

.choices { display: flex; gap: 10px; margin-top: 8px; flex-wrap: wrap; }
.choice {
  flex: 1 1 120px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  font-size: .95rem;
  cursor: pointer;
  text-align: center;
}
.choice.selected { border-color: var(--accent); background: #e8f0fe; font-weight: 600; }

/* Bloque de elección */
.options { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); margin-top: 12px; }
.option {
  border: 2px solid var(--line);
  border-radius: 12px;
  background: #fff;
  padding: 14px;
  cursor: pointer;
  text-align: left;
  font: inherit;
  color: inherit;
}
.option.selected { border-color: var(--accent); background: #f3f7ff; }
.option .name { font-weight: 800; letter-spacing: .08em; }
.option .acc { font-size: 1.4rem; font-weight: 700; margin: 6px 0; }
.option ul { padding-left: 18px; margin: 0; font-size: .9rem; }

/* Formulario */
.field { margin-top: 16px; }
.field label.q { display: block; font-weight: 600; margin-bottom: 6px; }
.field select, .field input[type=number], .field input[type=text] {
  width: 100%;
  padding: 10px;
  font-size: 1rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}
.likert { display: flex; gap: 6px; flex-wrap: wrap; }
.likert label {
  flex: 1 1 0;
  min-width: 44px;
  text-align: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px 2px;
  font-size: .8rem;
  cursor: pointer;
  background: #fff;
}
.likert input { display: block; margin: 0 auto 4px; }
.error { color: var(--warn); font-size: .9rem; margin-top: 10px; min-height: 1.2em; }

@media (max-width: 420px) {
  html, body { font-size: 16px; }
  .panel, .product { padding: 16px; }
  .features li { flex-wrap: wrap; gap: 4px 10px; }
  .features .k { flex: 0 0 auto; }
  .features li > span:last-child { flex: 1 1 100%; padding-left: 22px; }
}