:root {
  --bg: #0b0f14;
  --panel: #11161d;
  --panel-2: #151c25;
  --border: #1f2733;
  --text: #dbe4ee;
  --muted: #8b98a9;
  --accent: #e6b458;
  --accent-strong: #b8863b;
  --gold: #ffd60a;
  font-size: 15px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  line-height: 1.5;
}

/* ------------------------------------------------------------- cabecera */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  padding: 14px 28px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, #10151c, var(--bg));
}

.brand { display: flex; align-items: center; gap: 14px; }
.logo { width: 36px; height: 36px; color: var(--accent); }
.brand h1 { margin: 0; font-size: 1.15rem; letter-spacing: 0.2px; }
.tagline { margin: 0; color: var(--muted); font-size: 0.8rem; }

.tabs { display: flex; gap: 5px; background: var(--panel); border: 1px solid var(--border); padding: 4px; border-radius: 10px; flex-wrap: wrap; }
.tabs button {
  border: 0; background: transparent; color: var(--muted);
  padding: 7px 13px; border-radius: 7px; cursor: pointer; font: inherit; font-size: 0.9rem;
}
.tabs button:hover { color: var(--text); }
.tabs button.active { background: var(--accent-strong); color: #14100a; font-weight: 600; }

/* ------------------------------------------------------------ contenido */

main { max-width: 1280px; margin: 0 auto; padding: 20px 28px 40px; }

.view { display: none; }
.view.active { display: block; }

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px 18px;
}

h2 { margin: 0 0 4px; font-size: 0.95rem; font-weight: 600; }
.hint { margin: 0 0 10px; color: var(--muted); font-size: 0.8rem; }
.muted { color: var(--muted); }
.legend-hint { padding: 10px 4px 2px; }

/* controles */
.controls { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; margin-bottom: 16px; }
.controls label { display: flex; align-items: center; gap: 7px; color: var(--muted); font-size: 0.85rem; }
.controls output { color: var(--text); min-width: 2.2em; font-variant-numeric: tabular-nums; }

input[type="number"], select {
  background: var(--panel-2); color: var(--text);
  border: 1px solid var(--border); border-radius: 8px;
  padding: 7px 10px; font: inherit; width: 100px;
}
input[type="range"] { accent-color: var(--accent); width: 140px; }
input:focus { outline: 1px solid var(--accent); }

button {
  background: var(--panel-2); color: var(--text);
  border: 1px solid var(--border); border-radius: 8px;
  padding: 7px 14px; font: inherit; cursor: pointer;
}
button:hover { border-color: var(--accent); }
button.primary { background: var(--accent-strong); border-color: var(--accent-strong); color: #14100a; font-weight: 600; }
button.primary:hover { filter: brightness(1.12); }
button.ghost { padding: 7px 12px; }

.presets { display: flex; align-items: center; gap: 6px; font-size: 0.85rem; flex-wrap: wrap; }
.presets button { padding: 5px 10px; font-size: 0.8rem; }
.presets small { color: var(--muted); font-weight: 400; }

.status { color: var(--muted); font-size: 0.85rem; }
.status.error { color: #ff8080; }

/* ------------------------------------------------------------ gráficos */

.chart-card { padding-bottom: 10px; }
.chart-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 16px; flex-wrap: wrap; }

.canvas-box { position: relative; margin-top: 8px; border-radius: 10px; overflow: hidden; background: #0a0d12; border: 1px solid var(--border); }
.canvas-box canvas { display: block; width: 100%; height: 540px; cursor: crosshair; touch-action: none; }
.square-box { max-width: 660px; margin: 8px auto 0; }
.square-box canvas { aspect-ratio: 1; height: auto; }

.tip {
  position: absolute; pointer-events: none; z-index: 5;
  background: rgba(10, 13, 18, 0.94); border: 1px solid var(--border);
  border-radius: 8px; padding: 8px 11px; font-size: 0.8rem; line-height: 1.45;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.45); white-space: nowrap;
}
.tip b { color: var(--accent); }
.tip .row { display: flex; justify-content: space-between; gap: 14px; }
.tip .row span:first-child { color: var(--muted); }

/* ------------------------------------------------- casi-soluciones */

.near-grid {
  display: grid;
  grid-template-columns: minmax(420px, 1fr) minmax(360px, 1fr);
  gap: 16px;
  align-items: start;
}

.table-scroll { max-height: 480px; overflow: auto; border: 1px solid var(--border); border-radius: 10px; }
table { width: 100%; border-collapse: collapse; font-size: 0.85rem; font-variant-numeric: tabular-nums; }
thead th {
  position: sticky; top: 0; background: var(--panel-2); color: var(--muted);
  text-align: right; padding: 8px 10px; font-weight: 500; border-bottom: 1px solid var(--border);
}
tbody td { padding: 6px 10px; text-align: right; border-bottom: 1px solid #161d27; }
tbody tr:hover { background: #18202c; }
tbody tr.ensured { background: rgba(230, 180, 88, 0.14); }
tbody tr.ensured td { color: var(--accent); font-weight: 600; }
td.mono, .mono { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 0.82rem; }

/* ------------------------------------------------- curiosidades */

.curio-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(430px, 1fr));
  gap: 16px;
  margin-bottom: 16px;
}

.curio-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
  display: flex; flex-direction: column; gap: 12px;
}
.curio-card.simpsons { border-color: #3d3424; }
.curio-card.ramanujan { border-color: #24343d; }

.curio-card header { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.badge {
  font-size: 0.72rem; padding: 3px 9px; border-radius: 999px;
  background: var(--panel-2); border: 1px solid var(--border); color: var(--muted);
}
.curio-card h3 { margin: 0; font-size: 1.02rem; font-weight: 600; }

.digits { display: flex; flex-direction: column; gap: 4px; background: #0a0d12; border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px; overflow-x: auto; }
.digits code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.88rem; line-height: 1.5; white-space: nowrap;
}
.digits .lbl { color: var(--muted); font-size: 0.72rem; margin-right: 8px; }
.digits .match { color: #7dd3fc; }
.digits .diff { color: #ff6b6b; font-weight: 700; background: rgba(255, 107, 107, 0.12); border-radius: 3px; padding: 0 1px; }
.diff-demo {
  color: #ff6b6b; font-weight: 700; background: rgba(255, 107, 107, 0.12); border-radius: 3px; padding: 0 3px;
}

.curio-stats { display: flex; gap: 26px; margin: 0; }
.curio-stats dt { color: var(--muted); font-size: 0.75rem; }
.curio-stats dd { margin: 0; font-variant-numeric: tabular-nums; font-size: 0.95rem; }
.note { margin: 0; color: #b9c4d2; font-size: 0.85rem; flex-grow: 1; }

/* -------------------------------------------------------------- acerca */

.about-card { max-width: 760px; margin: 0 auto 16px; }
.about-card h2 { margin-top: 22px; font-size: 1rem; }
.about-card h2:first-child { margin-top: 0; }
.about-card p, .about-card li { color: #b9c4d2; }
.about-card ul { padding-left: 20px; }

.try-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 10px; margin: 8px 0 4px; }
.try-n { display: flex; flex-direction: column; gap: 4px; text-align: left; padding: 11px 13px; font-size: 0.95rem; font-weight: 600; }
.try-n small { color: var(--muted); font-weight: 400; font-size: 0.75rem; line-height: 1.35; }
.try-n:hover small { color: var(--text); }

a { color: var(--accent); }

footer {
  text-align: center; color: var(--muted); font-size: 0.8rem;
  padding: 18px; border-top: 1px solid var(--border); margin-top: 30px;
}

/* ---------------------------------------------------------- responsive */

@media (max-width: 980px) {
  main { padding: 14px; }
  .near-grid { grid-template-columns: 1fr; }
  .canvas-box canvas { height: 420px; }
  .curio-grid { grid-template-columns: 1fr; }
}