:root {
  --bg: #0f0e1c;
  --bg2: #171530;
  --card: #1d1a38;
  --line: rgba(255, 255, 255, 0.09);
  --text: #f4f2ff;
  --muted: #9d97c0;
  --accent: #ffd166;
  --accent2: #ef476f;
  --ok: #06d6a0;
  --info: #4cc9f0;
  --radius: 14px;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #faf8f3;
    --bg2: #ffffff;
    --card: #ffffff;
    --line: rgba(20, 16, 60, 0.1);
    --text: #191636;
    --muted: #6b6690;
  }
}

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

html { scroll-behavior: smooth; }

body {
  background:
    radial-gradient(900px 500px at 85% -10%, rgba(239, 71, 111, 0.18), transparent 60%),
    radial-gradient(800px 500px at -10% 10%, rgba(76, 201, 240, 0.15), transparent 55%),
    var(--bg);
  color: var(--text);
  font-family: -apple-system, "Segoe UI", Roboto, Inter, sans-serif;
  line-height: 1.6;
  min-height: 100vh;
}

.sr-only {
  position: absolute; width: 1px; height: 1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap;
}

/* ---------- Hero ---------- */
.hero { text-align: center; padding: clamp(28px, 5vw, 56px) 16px 24px; }

.nav {
  display: flex; align-items: center; justify-content: center; gap: 22px;
  flex-wrap: wrap; max-width: 720px; margin: 0 auto 34px;
}
.nav__brand {
  font-weight: 800; letter-spacing: 0.04em; font-size: 0.95rem;
  color: var(--accent);
  margin-right: auto;
}
.nav__link {
  color: var(--muted); text-decoration: none; font-size: 0.88rem;
  letter-spacing: 0.05em; transition: color 0.2s;
}
.nav__link:hover { color: var(--text); }

.hero__kicker {
  font-size: 0.75rem; letter-spacing: 0.32em; color: var(--accent2);
  font-weight: 700; margin-bottom: 14px;
}
.hero__title {
  font-size: clamp(2.4rem, 7vw, 4.4rem);
  line-height: 1.05; letter-spacing: -0.03em; font-weight: 900;
}
.hero__accent {
  background: linear-gradient(92deg, var(--accent), var(--accent2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero__sub { color: var(--muted); max-width: 520px; margin: 16px auto 0; }

/* ---------- Game ---------- */
.game { max-width: 560px; margin: 26px auto 40px; padding: 0 16px; }

.modes { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
.mode-btn {
  border: 1px solid var(--line); background: var(--bg2); color: var(--muted);
  padding: 12px 6px; min-height: 48px; border-radius: 12px; cursor: pointer;
  font-weight: 700; font-size: 0.9rem; letter-spacing: 0.03em;
  transition: all 0.2s ease;
}
.mode-btn:hover { transform: translateY(-2px); color: var(--text); border-color: var(--accent); }
.mode-btn.is-active {
  background: linear-gradient(135deg, var(--accent), #ffb84d);
  color: #1b1608; border-color: transparent;
  box-shadow: 0 6px 18px rgba(255, 209, 102, 0.35);
}
.mode-btn:focus-visible, .btn:focus-visible, .input-row__field:focus-visible,
.nav__link:focus-visible { outline: 2px solid var(--info); outline-offset: 2px; }

.board {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 20px; margin-top: 14px;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.35);
}

.board__top { display: flex; justify-content: space-between; gap: 8px; flex-wrap: wrap; }
.badge {
  font-size: 0.72rem; letter-spacing: 0.08em; font-weight: 700;
  padding: 5px 12px; border-radius: 999px; border: 1px solid var(--line);
  color: var(--muted);
}
.badge--score { color: var(--accent); }

.board__msg {
  min-height: 30px; margin: 16px 0 12px; font-size: 1.02rem; font-weight: 600;
  transition: color 0.2s;
}
.board__msg.ok { color: var(--ok); }
.board__msg.warn { color: var(--accent2); }
.board__msg.info { color: var(--info); }

.input-row { display: flex; gap: 8px; flex-wrap: wrap; }
.input-row__field {
  flex: 1 1 130px; min-width: 0;
  background: var(--bg2); border: 1px solid var(--line); border-radius: 10px;
  color: var(--text); font-size: 1.25rem; font-weight: 700;
  padding: 12px 16px; min-height: 52px; transition: border-color 0.2s;
}
.input-row__field::placeholder { color: var(--muted); font-weight: 400; font-size: 1rem; }
.input-row__field.err { animation: sacudir 0.35s ease; border-color: var(--accent2); }
@keyframes sacudir {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-6px); } 75% { transform: translateX(6px); }
}

.btn {
  border: none; border-radius: 10px; cursor: pointer; font-weight: 700;
  min-height: 52px; padding: 0 18px; font-size: 0.95rem;
  display: inline-flex; align-items: center; gap: 8px; justify-content: center;
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0) scale(0.97); }
.btn--primary {
  background: linear-gradient(135deg, var(--accent2), #d63d61);
  color: #fff; box-shadow: 0 6px 16px rgba(239, 71, 111, 0.35);
}
.btn--ghost {
  background: transparent; color: var(--muted); border: 1px solid var(--line);
}
.btn--ghost:hover { color: var(--text); border-color: var(--accent); }

.stats { display: flex; gap: 12px; margin-top: 16px; }
.stat {
  flex: 1; text-align: center; background: var(--bg2);
  border: 1px solid var(--line); border-radius: 10px; padding: 10px 6px;
}
.stat__num { display: block; font-size: 1.5rem; font-weight: 900; color: var(--accent); }
.stat__lbl { font-size: 0.62rem; letter-spacing: 0.18em; color: var(--muted); font-weight: 700; }

.historial {
  list-style: none; display: flex; flex-direction: column; gap: 6px;
  margin-top: 14px; max-height: 168px; overflow-y: auto; padding-right: 2px;
}
.historial li {
  display: flex; align-items: center; gap: 10px;
  background: var(--bg2); border: 1px solid var(--line);
  border-radius: 9px; padding: 8px 12px; font-size: 0.9rem;
  animation: fila 0.25s ease both;
}
@keyframes fila { from { opacity: 0; transform: translateX(-8px); } to { opacity: 1; } }
.historial__n {
  min-width: 46px; text-align: center; font-weight: 900;
  background: rgba(255, 209, 102, 0.14); color: var(--accent);
  border-radius: 6px; padding: 2px 6px; font-variant-numeric: tabular-nums;
}
.historial__resp { color: var(--muted); flex: 1; }
.historial__resp.mayor::after { content: " ▲"; color: var(--info); }
.historial__resp.menor::after { content: " ▼"; color: var(--accent2); }
.historial__resp.rep { color: var(--accent2); font-style: italic; }
.chips { display: flex; gap: 6px; }
.chip {
  width: 22px; height: 22px; border-radius: 6px; font-weight: 800; font-size: 0.72rem;
  display: inline-flex; align-items: center; justify-content: center; color: #10101e;
}
.chip--ok { background: var(--ok); }
.chip--parcial { background: var(--accent); }
.chip--mal { background: rgba(255, 255, 255, 0.14); color: var(--muted); }

.victoria { text-align: center; padding-top: 14px; animation: pop 0.5s cubic-bezier(0.2, 1.6, 0.4, 1) both; }
@keyframes pop { from { opacity: 0; transform: scale(0.6); } to { opacity: 1; transform: scale(1); } }
.victoria__confetti { width: 100%; max-width: 300px; height: auto; }
.victoria__num {
  font-size: 2.4rem; font-weight: 900; letter-spacing: 0.06em;
  background: linear-gradient(92deg, var(--ok), var(--accent));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.victoria__txt { color: var(--muted); }

/* ---------- Contenido ---------- */
.content {
  max-width: 680px; margin: 0 auto; padding: 34px 20px;
  border-top: 1px solid var(--line);
}
.content h2 { font-size: 1.5rem; letter-spacing: -0.02em; margin-bottom: 12px; }
.content h3 { font-size: 1.08rem; margin: 18px 0 8px; color: var(--accent); }
.content p, .content li { color: var(--muted); }
.steps { padding-left: 20px; display: grid; gap: 6px; }
.tip {
  margin-top: 18px; border-left: 3px solid var(--accent);
  background: var(--bg2); border-radius: 0 10px 10px 0; padding: 12px 16px;
}
details {
  background: var(--bg2); border: 1px solid var(--line); border-radius: 10px;
  padding: 12px 16px; margin-bottom: 8px;
}
summary { cursor: pointer; font-weight: 700; }
details p { margin-top: 8px; }

.footer {
  border-top: 1px solid var(--line); text-align: center;
  padding: 26px 16px; color: var(--muted); font-size: 0.85rem;
}
.footer nav { margin-top: 10px; display: flex; gap: 18px; justify-content: center; flex-wrap: wrap; }
.footer a { color: var(--accent); text-decoration: none; }

@media (max-width: 420px) {
  .modes { grid-template-columns: repeat(2, 1fr); }
  .nav__brand { margin-right: 0; width: 100%; text-align: center; }
  .board { padding: 16px; }
}