/* ═══════════ calculo — sistema visual ═══════════
   Tema claro amable para leer mates; el gate va oscuro para que la clave
   se sienta «puerta». Variables al principio: cambiar el tema aquí. */

:root {
  --bg: #eef2fb;
  --card: #ffffff;
  --ink: #17203a;
  --ink-soft: #4b5878;
  --line: #dde4f2;
  --brand: #4f46e5;
  --brand-2: #7c3aed;
  --ok: #16a34a;
  --warn: #d97706;
  --bad: #dc2626;
  --chip: #eef2ff;
  --radius: 18px;
  --shadow: 0 6px 24px rgba(23, 32, 58, .08);
  --t: .18s ease;
  /* colores didácticos fijos para gráficas (coordinar con engine/colors.js) */
  --g-a: #4f46e5;  /* curva principal */
  --g-b: #e11d48;  /* segunda curva */
  --g-c: #0891b2;  /* tercera */
  --g-d: #d97706;  /* cuarta */
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", sans-serif;
}
button { font: inherit; cursor: pointer; }
a { color: var(--brand); }

/* ─────────────── gate ─────────────── */
#gate {
  min-height: 100dvh; display: grid; place-items: center; padding: 1rem;
  background: radial-gradient(1200px 700px at 70% -10%, #1e2a5e 0%, #0b1220 55%);
}
#gate-form {
  width: min(92vw, 420px); text-align: center; color: #dbe4ff;
  background: rgba(13, 20, 40, .72); border: 1px solid #26315c;
  border-radius: 24px; padding: 2.4rem 2rem 2rem; box-shadow: 0 20px 60px rgba(0,0,0,.45);
  display: grid; gap: .8rem;
}
.gate-mark { font-size: 3.4rem; color: #818cf8; line-height: 1; }
#gate h1 { margin: 0; font-size: 1.7rem; letter-spacing: .02em; color: #f1f5ff; }
.gate-sub { margin: 0 0 .8rem; color: #8ea0d0; font-size: .95rem; }
#gate input {
  font: 600 1.15rem/1 ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  letter-spacing: .18em; text-align: center; text-transform: uppercase;
  padding: .9rem 1rem; border-radius: 14px; border: 1.5px solid #31407a;
  background: #0d1530; color: #eef2ff; outline: none; transition: border var(--t);
}
#gate input:focus { border-color: #6d7cff; box-shadow: 0 0 0 4px rgba(109,124,255,.18); }
#gate button {
  margin-top: .3rem; padding: .85rem 1rem; border: 0; border-radius: 14px;
  background: linear-gradient(135deg, #6366f1, #8b5cf6); color: #fff;
  font-weight: 700; font-size: 1.02rem; transition: transform var(--t), filter var(--t);
}
#gate button:active { transform: scale(.98); }
#gate button:hover { filter: brightness(1.08); }
.gate-err { margin: .2rem 0 0; color: #fda4af; font-size: .92rem; }

/* ─────────────── barra superior ─────────────── */
#topbar {
  position: sticky; top: 0; z-index: 30;
  display: flex; align-items: center; gap: .6rem;
  padding: .55rem 1rem; background: rgba(255,255,255,.86);
  backdrop-filter: blur(10px); border-bottom: 1px solid var(--line);
}
#brand { font-weight: 800; letter-spacing: .01em; }
#brand .mark { color: var(--brand); font-size: 1.25em; }
#top-right { margin-left: auto; display: flex; align-items: center; gap: .55rem; }
.icon-btn {
  border: 1px solid var(--line); background: var(--card); border-radius: 12px;
  padding: .32rem .7rem; font-weight: 700; color: var(--ink);
}
.icon-btn:hover { border-color: var(--brand); color: var(--brand); }
#who { font-size: .88rem; color: var(--ink-soft); max-width: 30vw; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
#who b { color: var(--ink); }

.ring-mini { width: 34px; height: 34px; display: inline-block; }
.ring-mini svg { display: block; }

/* ─────────────── vistas ─────────────── */
#view { max-width: 1060px; margin: 0 auto; padding: 1.1rem 1rem 6rem; }
.view-title { font-size: 1.55rem; margin: 1.2rem .2rem .3rem; }
.view-sub { color: var(--ink-soft); margin: 0 .2rem 1.2rem; }

/* menú de capítulos */
.chapter-card {
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  color: #fff; border-radius: var(--radius); padding: 1.3rem 1.4rem;
  box-shadow: var(--shadow); margin-bottom: 1.1rem;
}
.chapter-card h2 { margin: 0 0 .2rem; font-size: 1.3rem; }
.chapter-card p { margin: 0; opacity: .85; font-size: .93rem; }
.section-grid { display: grid; gap: .9rem; grid-template-columns: repeat(auto-fill, minmax(255px, 1fr)); }
.sec-card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1rem 1.1rem; box-shadow: var(--shadow); cursor: pointer;
  display: grid; grid-template-columns: 1fr auto; gap: .3rem .8rem; align-items: center;
  transition: transform var(--t), border var(--t); text-align: left;
}
.sec-card:hover { transform: translateY(-3px); border-color: #b9c4ff; }
.sec-card .num { font-weight: 800; color: var(--brand); font-size: .85rem; }
.sec-card h3 { grid-column: 1 / -1; margin: 0; font-size: 1.06rem; }
.sec-card .meta { grid-column: 1 / -1; color: var(--ink-soft); font-size: .84rem; }
.sec-card .ring { width: 46px; height: 46px; }
.sec-card.soon { opacity: .55; cursor: default; }
.pill { display: inline-block; border-radius: 99px; padding: .08rem .6rem; font-size: .78rem; font-weight: 700; background: var(--chip); color: var(--brand); }
.pill.done { background: #dcfce7; color: var(--ok); }

/* ─────────────── página de sección ─────────────── */
.sec-head h2 { margin: .4rem 0 .1rem; font-size: 1.35rem; }
.sec-head .crumb { color: var(--ink-soft); font-size: .85rem; }
.tabs { display: flex; gap: .45rem; margin: .9rem 0 1.1rem; flex-wrap: wrap; }
.tab {
  border: 1px solid var(--line); background: var(--card); border-radius: 99px;
  padding: .5rem 1.05rem; font-weight: 700; color: var(--ink-soft);
  display: inline-flex; align-items: center; gap: .45rem; transition: all var(--t);
}
.tab .dot { width: 8px; height: 8px; border-radius: 50%; background: #cbd5e1; }
.tab.active { background: var(--brand); border-color: var(--brand); color: #fff; }
.tab.active .dot { background: #fff; }
.tab.done-tab .dot { background: var(--ok); }
.tab.active.done-tab .dot { background: #86efac; }

/* bloques de teoría */
.block { margin: 0 0 1rem; }
.card-block {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.15rem 1.3rem; box-shadow: var(--shadow);
}
.callout { border-left: 5px solid var(--brand); border-radius: 12px; background: #eef2ff; padding: .9rem 1.1rem; margin: 0 0 1rem; }
.callout.idea { border-color: var(--ok); background: #ecfdf5; }
.callout.tip { border-color: var(--warn); background: #fffbeb; }
.callout.warn { border-color: var(--bad); background: #fef2f2; }
.callout .co-title { font-weight: 800; margin-bottom: .15rem; }
h3.b-title { font-size: 1.12rem; margin: 1.6rem .1rem .7rem; display: flex; align-items: center; gap: .5rem; }
h3.b-title .n { background: var(--brand); color: #fff; border-radius: 10px; font-size: .8rem; padding: .1rem .55rem; }

.reveal-btn {
  margin-top: .6rem; border: 1.5px dashed #b9c4ff; background: #f7f8ff; color: var(--brand);
  border-radius: 12px; padding: .5rem 1rem; font-weight: 700;
}
details.reveal summary { list-style: none; cursor: pointer; }
details.reveal summary::-webkit-details-marker { display: none; }
details.reveal summary .reveal-btn { display: inline-block; }
details.reveal[open] summary .reveal-btn { display: none; }

/* widgets */
.widget {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: .9rem; margin: .4rem 0 1.15rem;
}
.widget .w-head { display: flex; align-items: baseline; gap: .6rem; flex-wrap: wrap; margin-bottom: .4rem; }
.widget .w-title { font-weight: 800; font-size: .95rem; }
.widget .w-note { color: var(--ink-soft); font-size: .84rem; }
.widget svg.graph { width: 100%; height: auto; display: block; touch-action: none; user-select: none; }
.w-controls { display: grid; gap: .55rem; margin-top: .7rem; }
.w-slider { display: grid; grid-template-columns: 74px 1fr 64px; gap: .6rem; align-items: center; }
.w-slider label { font-weight: 700; font-size: .88rem; text-align: right; }
.w-slider output { font-variant-numeric: tabular-nums; background: var(--chip); border-radius: 8px; padding: .12rem .5rem; text-align: center; font-weight: 700; font-size: .86rem; }
.w-slider input[type=range] { width: 100%; accent-color: var(--brand); height: 30px; }
.w-btns { display: flex; gap: .4rem; flex-wrap: wrap; margin-top: .6rem; }
.w-btn { border: 1px solid var(--line); background: #f7f8ff; border-radius: 10px; padding: .35rem .8rem; font-weight: 600; font-size: .86rem; }
.w-btn.on { background: var(--brand); color: #fff; border-color: var(--brand); }
.legend { display: flex; gap: .9rem; flex-wrap: wrap; font-size: .82rem; margin-top: .35rem; }
.legend .it { display: inline-flex; align-items: center; gap: .35rem; }
.legend .sw { width: 16px; height: 4px; border-radius: 2px; display: inline-block; }

/* pasos de práctica */
.steps-nav { display: flex; align-items: center; gap: .6rem; margin: .8rem 0; flex-wrap: wrap; }
.step-pill { border-radius: 99px; border: 1px solid var(--line); background: var(--card); padding: .3rem .75rem; font-weight: 700; font-size: .85rem; color: var(--ink-soft); }
.step-pill.cur { background: var(--brand); border-color: var(--brand); color: #fff; }
.step-pill.ok { border-color: #a7f3d0; color: var(--ok); }
.ex-card { border: 1px solid var(--line); background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); padding: 1.15rem 1.3rem; margin-bottom: 1rem; }
.ex-src { font-size: .8rem; color: var(--ink-soft); }
.ex-body { margin-top: .6rem; }
.answer-box { border: 1.5px dashed #86efac; background: #f0fdf4; border-radius: 12px; padding: .8rem 1rem; margin-top: .8rem; }
.answer-box .lbl { font-weight: 800; color: var(--ok); font-size: .85rem; }

/* quiz */
.q-card { border: 1px solid var(--line); background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); padding: 1.2rem 1.35rem; margin-bottom: 1rem; }
.q-num { font-size: .8rem; font-weight: 800; color: var(--brand); }
.q-text { font-size: 1.02rem; margin: .35rem 0 .8rem; }
.q-opts { display: grid; gap: .5rem; }
.q-opt {
  border: 1.5px solid var(--line); background: #fff; border-radius: 12px;
  padding: .65rem .9rem; text-align: left; display: flex; gap: .6rem; align-items: center;
  transition: all var(--t);
}
.q-opt:hover { border-color: #b9c4ff; }
.q-opt .k { border-radius: 8px; background: var(--chip); color: var(--brand); font-weight: 800; padding: .05rem .5rem; font-size: .85rem; }
.q-opt.correct { border-color: var(--ok); background: #f0fdf4; }
.q-opt.wrong { border-color: var(--bad); background: #fef2f2; }
.q-explain { margin-top: .7rem; border-radius: 12px; background: #f1f5f9; padding: .7rem .95rem; font-size: .92rem; }
.q-foot { display: flex; justify-content: space-between; align-items: center; gap: .6rem; margin-top: 1rem; flex-wrap: wrap; }
.btn {
  border: 0; border-radius: 13px; padding: .62rem 1.2rem; font-weight: 800;
  background: var(--brand); color: #fff; transition: transform var(--t), filter var(--t);
}
.btn:hover { filter: brightness(1.07); }
.btn:active { transform: scale(.97); }
.btn.ghost { background: var(--card); color: var(--brand); border: 1.5px solid var(--line); }
.btn.ok { background: var(--ok); }
.score-big { font-size: 2.6rem; font-weight: 900; }
.match-grid { display: grid; grid-template-columns: 1fr 1fr; gap: .5rem .5rem; }
.match-item { border: 2px solid var(--line); border-radius: 12px; padding: .6rem .8rem; background: #fff; cursor: pointer; text-align: center; transition: all var(--t); }
.match-item.sel { border-color: var(--brand); background: #eef2ff; }
.match-item.ok { border-color: var(--ok); background: #f0fdf4; cursor: default; opacity: .8; }
.match-item.bad { animation: shake .3s; border-color: var(--bad); }
@keyframes shake { 25% { transform: translateX(-4px);} 75% { transform: translateX(4px);} }

.fill-input { width: 140px; font-size: 1.05rem; padding: .45rem .7rem; border: 1.5px solid var(--line); border-radius: 10px; }
.fill-input:focus { outline: none; border-color: var(--brand); }

/* navegación inferior de sección */
.sec-foot { display: flex; justify-content: space-between; gap: .6rem; margin-top: 1.4rem; }

/* toast */
#toast-host { position: fixed; left: 50%; bottom: 1.4rem; transform: translateX(-50%); z-index: 60; display: grid; gap: .5rem; }
.toast {
  background: #17203a; color: #fff; border-radius: 14px; padding: .65rem 1.1rem;
  font-weight: 600; box-shadow: 0 10px 30px rgba(0,0,0,.3); animation: up .25s ease;
}
.toast.ok { background: #15803d; }
@keyframes up { from { transform: translateY(12px); opacity: 0; } }

/* apodo modal */
.modal-veil { position: fixed; inset: 0; background: rgba(10,15,35,.55); display: grid; place-items: center; z-index: 50; padding: 1rem; }
.modal { background: #fff; border-radius: 22px; padding: 1.6rem 1.7rem; width: min(92vw, 430px); box-shadow: 0 25px 70px rgba(0,0,0,.35); }
.modal h3 { margin: 0 0 .3rem; }
.modal p { margin: 0 0 .9rem; color: var(--ink-soft); font-size: .92rem; }
.modal input { width: 100%; padding: .7rem .9rem; border: 1.5px solid var(--line); border-radius: 12px; font-size: 1rem; }
.modal input:focus { outline: none; border-color: var(--brand); }
.modal .row { display: flex; gap: .6rem; justify-content: flex-end; margin-top: 1rem; }

/* progreso anular inline */
.ring-wrap { display: inline-grid; place-items: center; }

/*katex un poco más grande en bloques */
.katex-display { margin: .55rem 0; overflow-x: auto; overflow-y: hidden; }
.katex { font-size: 1.06em; }

@media (max-width: 640px) {
  #view { padding: .8rem .7rem 5rem; }
  .card-block, .ex-card, .q-card { padding: 1rem; }
  .w-slider { grid-template-columns: 64px 1fr 56px; }
}