:root {
  --primary: #FF561D;
  --secondary: #555B97;
  --accent: #5CB9FC;
  --bg: #0a0a0a;
  --surface: #1a1a1a;
  --surface-2: #242424;
  --border: #2e2e2e;
  --text: #ffffff;
  --muted: #a0a0a0;
  --radius: 12px;
}

* { box-sizing: border-box; }
html, body { margin: 0; background: var(--bg); color: var(--text); }
body { font-family: 'Inter', system-ui, sans-serif; line-height: 1.55; min-height: 100vh; -webkit-font-smoothing: antialiased; }
button, input, textarea { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.fade { animation: fade .35s ease-out; }
@keyframes fade { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }

.btn {
  background: var(--primary); color: #fff; border: 0; border-radius: 10px; padding: 13px 26px; font-weight: 600; font-size: 16px;
  cursor: pointer; transition: transform .1s, filter .15s;
}
.btn:hover { filter: brightness(1.08); }
.btn:active { transform: scale(.98); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn.block { width: 100%; }

/* ---------- inicio ---------- */
.intro { min-height: 100vh; display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 40px 20px; text-align: center; }
.intro-inner { width: 100%; max-width: 720px; }
.intro .logo { height: 46px; width: auto; margin-bottom: 36px; }
.intro h1 { font-size: clamp(30px, 6vw, 44px); line-height: 1.1; margin: 0 0 28px; letter-spacing: -.025em; }
.letter { text-align: left; background: var(--surface); border: 1px solid var(--border); border-left: 3px solid var(--primary); border-radius: var(--radius); padding: 22px 24px; margin: 0 0 20px; }
.letter p { margin: 0 0 14px; font-size: 17px; color: #d6d6d6; }
.letter p:last-child { margin-bottom: 0; }
.letter .sign { color: var(--primary); font-weight: 600; margin-top: 4px; }
.start { background: var(--surface); border: 1px solid var(--border); border-radius: 16px; padding: 24px; text-align: left; }
.start label { display: block; font-weight: 600; margin-bottom: 8px; }
.start input {
  width: 100%; background: var(--bg); border: 1px solid var(--border); border-radius: 10px; padding: 14px 16px; font-size: 17px; margin-bottom: 16px;
}
.start input:focus { border-color: var(--accent); outline: none; }
.start .err { color: #ff7b7b; font-size: 14px; margin: -8px 0 12px; }
.start .err:empty { display: none; }

/* ---------- cabecera ---------- */
.top { position: sticky; top: 0; z-index: 5; background: rgba(10, 10, 10, .94); backdrop-filter: blur(6px); border-bottom: 1px solid var(--border); }
.top-row { max-width: 760px; margin: 0 auto; padding: 12px 20px; display: flex; align-items: center; gap: 16px; }
.top-row img { height: 26px; width: auto; }
.top-row .step { color: var(--muted); font-size: 14px; flex: 1; }
.timer { font-variant-numeric: tabular-nums; font-weight: 600; padding: 4px 12px; border-radius: 999px; background: var(--surface); border: 1px solid var(--border); }
.timer.low { color: var(--primary); border-color: var(--primary); }
.bar { height: 3px; background: var(--surface); }
.bar > i { display: block; height: 100%; width: 0; background: var(--primary); transition: width .3s; }

/* ---------- preguntas ---------- */
.page { max-width: 760px; margin: 0 auto; padding: 8px 20px 56px; }
.page h2 { font-size: clamp(24px, 4.5vw, 32px); margin: 28px 0 10px; letter-spacing: -.02em; line-height: 1.2; }
.page .text { font-size: 17px; color: #d6d6d6; margin: 0 0 18px; }
.facts-title { font-weight: 600; margin: 0 0 8px; }
.facts { list-style: none; margin: 0 0 20px; padding: 0; display: grid; gap: 8px; }
.facts li { background: var(--surface); border: 1px solid var(--border); border-left: 3px solid var(--secondary); border-radius: 8px; padding: 11px 14px; }
.final { border-left: 3px solid var(--primary); background: var(--surface); padding: 14px 16px; border-radius: 0 var(--radius) var(--radius) 0; margin: 0 0 24px; font-size: 17px; }
.final small { display: block; color: var(--muted); text-transform: uppercase; letter-spacing: .06em; font-size: 12px; margin-bottom: 4px; }

.q { margin-top: 28px; }
.q-head { display: flex; gap: 12px; align-items: flex-start; margin-bottom: 12px; }
.q-num { flex: none; width: 28px; height: 28px; border-radius: 50%; background: var(--primary); color: #fff; font-weight: 700; font-size: 14px; display: grid; place-items: center; margin-top: 1px; }
.q-head h3 { margin: 0; font-size: 19px; line-height: 1.35; }
.opts { display: grid; gap: 8px; }
.opt { display: flex; gap: 12px; align-items: flex-start; background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: 13px 15px; cursor: pointer; transition: border-color .15s; }
.opt:hover { border-color: var(--secondary); }
.opt input { accent-color: var(--primary); margin-top: 4px; width: 17px; height: 17px; flex: none; }
.opt.sel { border-color: var(--primary); background: #1f1511; }

/* clasificar */
.rows { display: grid; gap: 10px; }
.row { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px; display: grid; grid-template-columns: 1fr auto; gap: 14px; align-items: center; }
.seg { display: flex; gap: 6px; }
.seg label { cursor: pointer; }
.seg input { position: absolute; opacity: 0; pointer-events: none; }
.seg span { display: block; padding: 9px 12px; border: 1px solid var(--border); border-radius: 9px; font-size: 14px; font-weight: 500; white-space: nowrap; background: var(--bg); transition: border-color .15s, background .15s; }
.seg label:hover span { border-color: var(--secondary); }
.seg input:checked + span { border-color: var(--primary); background: #2a1710; color: #fff; }
.seg input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 2px; }
.legend { display: flex; flex-wrap: wrap; gap: 6px 18px; color: var(--muted); font-size: 14px; margin: 0 0 16px; }
.legend b { color: #d6d6d6; font-weight: 600; }

/* abierta */
textarea { width: 100%; min-height: 140px; resize: vertical; background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: 14px 16px; font-size: 16px; }
textarea:focus { border-color: var(--accent); outline: none; }
.counter { text-align: right; color: var(--muted); font-size: 13px; margin-top: 4px; }

.actions { display: flex; justify-content: flex-end; margin-top: 32px; }

/* final */
.done { min-height: 100vh; display: grid; place-content: center; text-align: center; padding: 24px; }
.done .tick { width: 68px; height: 68px; border-radius: 50%; background: var(--primary); display: grid; place-items: center; font-size: 34px; margin: 0 auto 22px; }
.done h1 { margin: 0 0 10px; font-size: clamp(26px, 5vw, 36px); }
.done p { color: var(--muted); font-size: 18px; margin: 0; }

@media (max-width: 720px) {
  .row { grid-template-columns: 1fr; }
  .seg { display: grid; grid-template-columns: 1fr; }
  .seg span { text-align: center; white-space: normal; }
  .top-row { gap: 10px; padding: 10px 16px; }
  .top-row .step { font-size: 12px; }
  .page { padding: 4px 16px 48px; }
}
@media (prefers-reduced-motion: reduce) { .fade { animation: none; } .bar > i { transition: none; } }