/* RegreLab — cuaderno de laboratorio: papel cuadriculado, tinta azul, títulos con serif y cifras en monoespaciada */

@font-face { font-family: "Newsreader"; font-style: normal; font-weight: 200 800; font-display: swap; src: url("../vendor/fonts/newsreader-latin-wght-normal.woff2") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "Newsreader"; font-style: italic; font-weight: 200 800; font-display: swap; src: url("../vendor/fonts/newsreader-latin-wght-italic.woff2") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "IBM Plex Sans"; font-style: normal; font-weight: 400; font-display: swap; src: url("../vendor/fonts/ibm-plex-sans-latin-400-normal.woff2") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "IBM Plex Sans"; font-style: normal; font-weight: 500; font-display: swap; src: url("../vendor/fonts/ibm-plex-sans-latin-500-normal.woff2") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "IBM Plex Sans"; font-style: normal; font-weight: 600; font-display: swap; src: url("../vendor/fonts/ibm-plex-sans-latin-600-normal.woff2") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "IBM Plex Sans"; font-style: italic; font-weight: 400; font-display: swap; src: url("../vendor/fonts/ibm-plex-sans-latin-400-italic.woff2") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "IBM Plex Sans"; font-style: normal; font-weight: 400; font-display: swap; src: url("../vendor/fonts/ibm-plex-sans-latin-ext-400-normal.woff2") format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "IBM Plex Sans"; font-style: normal; font-weight: 600; font-display: swap; src: url("../vendor/fonts/ibm-plex-sans-latin-ext-600-normal.woff2") format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "IBM Plex Mono"; font-style: normal; font-weight: 400; font-display: swap; src: url("../vendor/fonts/ibm-plex-mono-latin-400-normal.woff2") format("woff2"); }
@font-face { font-family: "IBM Plex Mono"; font-style: normal; font-weight: 500; font-display: swap; src: url("../vendor/fonts/ibm-plex-mono-latin-500-normal.woff2") format("woff2"); }
@font-face { font-family: "IBM Plex Mono"; font-style: normal; font-weight: 600; font-display: swap; src: url("../vendor/fonts/ibm-plex-mono-latin-600-normal.woff2") format("woff2"); }

:root {
  --paper: #f4f0e6;
  --bg: var(--paper);
  --card: #fdfbf5;
  --card-2: #efe9db;
  --text: #1a2036;
  --muted: #576078;
  --rule: #d9d1be;
  --border: var(--rule);
  --rule-2: #b7ad96;
  --grid: #e3dbca;
  --gridline: rgba(31, 56, 100, .055);
  --primary: #1f3864;
  --primary-t: #ffffff;
  --accent: #1f3864;
  --link: #1a4fa8;
  --green: #2e7d32;
  --green-line: rgba(46, 125, 50, .38);
  --green-bg: #e8f1e4;
  --blue-b: #1f3864;
  --blue-bg: rgba(31, 56, 100, .065);
  --amber-bg: #fbf0cd;
  --amber-b: #c88a00;
  --amber-t: #5f4200;
  --note-bg: #ece6d8;
  --red-bg: #f7e3df;
  --sst: #7b3fa0;
  --ssr: #1e6fd9;
  --sse: #c62828;
  --serif: "Newsreader", Georgia, "Times New Roman", serif;
  --sans: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, "Cascadia Mono", Consolas, monospace;
  --radius: 8px;
  --nav-h: 64px;
  color-scheme: light;
}

:root[data-theme="dark"] {
  --paper: #0e1424;
  --card: #151c31;
  --card-2: #1c2542;
  --text: #e9e5d9;
  --muted: #a3aabe;
  --rule: #2b3555;
  --rule-2: #3d4a70;
  --grid: #27314f;
  --gridline: rgba(255, 255, 255, .032);
  --primary: #3f66b3;
  --accent: #98b7ee;
  --link: #93b8ff;
  --green-bg: #172a1b;
  --green-line: rgba(111, 207, 118, .4);
  --blue-b: #98b7ee;
  --blue-bg: rgba(152, 183, 238, .1);
  --amber-bg: #372e10;
  --amber-b: #e6b422;
  --amber-t: #ffe08a;
  --note-bg: #1a2340;
  --red-bg: #3a1c1e;
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: 84px; }
body {
  margin: 0; color: var(--text); font: 400 1rem/1.6 var(--sans);
  background-color: var(--paper);
  background-image: linear-gradient(var(--gridline) 1px, transparent 1px), linear-gradient(90deg, var(--gridline) 1px, transparent 1px);
  background-size: 26px 26px;
  padding-bottom: calc(var(--nav-h) + 16px + env(safe-area-inset-bottom));
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, h4, h5 { font-family: var(--serif); font-weight: 600; line-height: 1.18; margin: 0 0 .5rem; color: var(--text); letter-spacing: -.005em; }
h2 { font-size: 2rem; }
h3 { font-size: 1.3rem; }
h5 { font-size: 1.1rem; }
p { margin: .4rem 0 .75rem; }
a { color: var(--link); text-underline-offset: 2px; }
strong { font-weight: 600; }
.small { font-size: .9rem; color: var(--muted); }
.lead { font-size: 1.1rem; color: var(--muted); max-width: 46rem; }
.opt { font: 400 .9rem var(--sans); color: var(--muted); }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip { position: absolute; left: -999px; top: 0; background: #fff; color: #000; padding: .6rem 1rem; z-index: 200; }
.skip:focus { left: 8px; top: 8px; }
:focus-visible { outline: 3px solid var(--amber-b); outline-offset: 2px; border-radius: 4px; }
.print-only { display: none; }
.ico { display: inline-flex; flex: none; }
.ico svg, .ic svg { display: block; }
.i { flex: none; }
.kicker { display: block; font: 500 .8rem var(--mono); letter-spacing: .16em; color: var(--muted); margin-bottom: .2rem; }
.kicker::after { content: ""; display: inline-block; width: 2.4rem; height: 1px; background: currentColor; vertical-align: middle; margin-left: .7rem; }

/* ---------- barra superior ---------- */
.topbar {
  position: sticky; top: 0; z-index: 40; display: flex; align-items: center; justify-content: space-between; gap: .5rem;
  background: var(--paper); border-bottom: 1px solid var(--rule-2);
  padding: .45rem .8rem; padding-top: calc(.45rem + env(safe-area-inset-top));
}
.brand { display: flex; align-items: center; gap: .65rem; min-width: 0; }
.logo { flex: none; border-radius: 6px; }
.brand-t { display: flex; flex-direction: column; line-height: 1.1; }
.brand-n { font: 700 1.55rem var(--serif); letter-spacing: -.01em; }
.brand-n em { font-style: italic; font-weight: 500; color: var(--accent); }
.brand-s { display: none; font: 400 .8rem var(--sans); color: var(--muted); letter-spacing: .01em; }
.top-actions { display: flex; gap: .35rem; }
.top-btn {
  min-height: 44px; min-width: 44px; padding: 0 .7rem; border-radius: 6px; border: 1px solid var(--rule-2);
  background: var(--card); color: var(--text); font: 500 .95rem var(--sans); cursor: pointer;
  display: inline-flex; align-items: center; justify-content: center; gap: .5rem;
}
.top-btn:hover { background: var(--card-2); border-color: var(--text); }
.top-btn .lbl { display: none; }
.top-btn.dim { opacity: .55; }

/* ---------- navegación ---------- */
.nav {
  position: fixed; z-index: 45; left: 0; right: 0; bottom: 0; display: grid; grid-template-columns: repeat(4, 1fr);
  background: var(--card); border-top: 1px solid var(--rule-2); padding-bottom: env(safe-area-inset-bottom);
}
.nav button {
  min-height: var(--nav-h); border: 0; background: transparent; color: var(--muted); font: 500 .8rem var(--sans);
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 3px; cursor: pointer; position: relative;
}
.nav .n-num, .nav-foot { display: none; }
.nav button[aria-current="page"] { color: var(--accent); font-weight: 600; }
.nav button[aria-current="page"]::before { content: ""; position: absolute; top: -1px; left: 18%; right: 18%; height: 3px; background: var(--accent); }

main { max-width: 1000px; margin: 0 auto; padding: 1.1rem .9rem 2rem; }
.view { animation: fadein .28s ease; }
@keyframes fadein { from { opacity: 0; transform: translateY(5px); } to { opacity: 1; transform: none; } }

@media (min-width: 900px) {
  body { padding-bottom: 0; padding-left: 224px; }
  .brand-s { display: block; }
  .top-btn .lbl { display: inline; }
  .topbar { margin-left: -224px; padding-left: 1.1rem; padding-right: 1.1rem; }
  .nav {
    top: 66px; right: auto; bottom: 0; width: 224px; grid-template-columns: 1fr; grid-auto-rows: 52px; align-content: start;
    border-top: 0; border-right: 1px solid var(--rule-2); padding: 1.2rem 0 0; background: var(--paper);
  }
  .nav button { flex-direction: row; justify-content: flex-start; gap: .9rem; padding: 0 1.3rem; font-size: 1.02rem; text-align: left; }
  .nav .n-ic { display: none; }
  .nav .n-num { display: inline; font: 500 .8rem var(--mono); letter-spacing: .1em; color: var(--muted); }
  .nav button:hover { background: var(--card-2); }
  .nav button[aria-current="page"] { background: var(--card); color: var(--text); }
  .nav button[aria-current="page"]::before { top: 0; bottom: 0; left: 0; right: auto; width: 4px; height: auto; }
  .nav button[aria-current="page"] .n-num { color: var(--accent); }
  .nav-foot { display: block; position: absolute; left: 1.3rem; right: 1.2rem; bottom: 1.4rem; margin: 0; font: italic 400 .85rem/1.45 var(--serif); color: var(--muted); }
  main { padding: 1.6rem 1.8rem 3rem; }
  html { scroll-padding-top: 88px; }
}

/* ---------- componentes básicos ---------- */
.card {
  background: var(--card); border: 1px solid var(--rule-2); border-radius: var(--radius);
  box-shadow: 2px 2px 0 var(--rule); padding: 1.1rem 1.2rem; margin: 0 0 1.1rem;
}
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .55rem; min-height: 44px; padding: .5rem 1rem; border-radius: 6px;
  border: 1px solid var(--rule-2); background: var(--card); color: var(--text); font: 500 1rem var(--sans); cursor: pointer;
  transition: background .15s, border-color .15s, transform .08s;
}
.btn:hover { background: var(--card-2); border-color: var(--text); }
.btn:active { transform: translateY(1px); }
.btn.primary { background: var(--primary); color: var(--primary-t); border-color: var(--primary); box-shadow: 0 2px 0 rgba(0, 0, 0, .3); }
.btn.primary:hover { background: color-mix(in srgb, var(--primary) 86%, #000); border-color: var(--primary); }
.btn.ghost { background: transparent; }
.btn.small { padding: .35rem .75rem; font-size: .92rem; }
.btn.big { width: 100%; font-size: 1.2rem; min-height: 58px; margin: .4rem 0 1rem; font-family: var(--serif); font-weight: 600; letter-spacing: .01em; }
.btn.dim { opacity: .78; }
.btn:disabled { opacity: .5; cursor: default; transform: none; }
.btn-row { display: flex; flex-wrap: wrap; gap: .5rem; margin: .75rem 0; }
.btn-row.center { justify-content: center; }
.grid2 { display: grid; gap: .85rem; grid-template-columns: 1fr; }
@media (min-width: 640px) { .grid2 { grid-template-columns: 1fr 1fr; } }
.field { display: flex; flex-direction: column; gap: .3rem; font: 500 .92rem var(--sans); border: 0; padding: 0; margin: 0; }
input[type="text"], input[type="search"], select, textarea {
  font: 400 1rem var(--sans); color: var(--text); background: var(--card); border: 1px solid var(--rule-2); border-radius: 6px;
  padding: .55rem .7rem; min-height: 44px; width: 100%;
}
input:focus, select:focus, textarea:focus { border-color: var(--accent); outline: 2px solid var(--accent); outline-offset: 0; }
input[type="checkbox"], input[type="radio"] { width: 22px; height: 22px; accent-color: var(--primary); flex: none; }
.check, .radios label { display: flex; align-items: center; gap: .6rem; min-height: 44px; font-weight: 400; cursor: pointer; }
.radios { margin-top: .9rem; }
.radios legend { font-weight: 500; padding: 0; margin-bottom: .2rem; }
.chips { display: flex; gap: .4rem; align-items: center; flex-wrap: wrap; }
.chips input { width: 96px; font-family: var(--mono); }
.chip-btn { min-height: 44px; min-width: 58px; border: 1px solid var(--rule-2); border-radius: 6px; background: var(--card); color: var(--text); font: 500 1rem var(--mono); cursor: pointer; }
.chip-btn:hover { border-color: var(--text); }
.chip-btn[aria-pressed="true"] { background: var(--primary); color: #fff; border-color: var(--primary); box-shadow: 0 2px 0 rgba(0, 0, 0, .3); }

/* ---------- tabla de datos ---------- */
.tbl-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; margin: .5rem 0; }
.data-tbl table { width: 100%; border-collapse: collapse; }
.data-tbl th { text-align: left; padding: .45rem .3rem; font: 600 .9rem var(--sans); color: var(--muted); border-bottom: 2px solid var(--text); }
.data-tbl td { padding: .25rem; }
.data-tbl .idx { width: 44px; text-align: center; font-family: var(--mono); color: var(--muted); }
.data-tbl input.cell { text-align: right; font-family: var(--mono); }
.icon-btn { min-width: 44px; min-height: 44px; border: 0; background: transparent; color: var(--muted); border-radius: 6px; cursor: pointer; display: inline-flex; align-items: center; justify-content: center; }
.icon-btn:hover { background: var(--red-bg); color: var(--sse); }

.msg, .warn, .note, .interp { display: flex; gap: .75rem; padding: .7rem .95rem; margin: .65rem 0; align-items: flex-start; border-left: 3px solid var(--muted); border-radius: 0 6px 6px 0; }
.msg > div, .warn > div, .note > div, .interp > .body { flex: 1; min-width: 0; }
.msg p, .warn p, .note p, .interp p { margin: .25rem 0; }
.ic { flex: none; line-height: 1; padding-top: .18rem; }
.msg.err { background: var(--red-bg); border-left-color: var(--sse); } .msg.err .ic { color: var(--sse); }
.msg.warn-m, .warn { background: var(--amber-bg); border-left-color: var(--amber-b); } .msg.warn-m .ic, .warn .ic { color: var(--amber-b); }
.msg.note-m, .note { background: var(--note-bg); } .msg.note-m .ic, .note .ic { color: var(--muted); }
.msg.ok { background: var(--green-bg); border-left-color: var(--green); } .msg.ok .ic { color: var(--green); }
.interp { display: block; background: var(--blue-bg); border-left-color: var(--blue-b); }
.interp .lab { display: flex; align-items: center; gap: .45rem; font: 600 .78rem var(--mono); letter-spacing: .12em; text-transform: uppercase; color: var(--accent); margin-bottom: .1rem; }
#validation.shake { animation: shake .4s; }
@keyframes shake { 20%, 60% { transform: translateX(-6px); } 40%, 80% { transform: translateX(6px); } }
.stack { display: grid; gap: .1rem; }

/* ---------- resultados ---------- */
.view-head { display: flex; flex-wrap: wrap; gap: .6rem 1rem; align-items: flex-end; justify-content: space-between; margin-bottom: .8rem; }
.view-head h2 { margin: 0; }
.toolbar { display: flex; flex-wrap: wrap; gap: .5rem; align-items: center; }
.seg { display: inline-flex; border: 1px solid var(--rule-2); border-radius: 6px; overflow: hidden; background: var(--card); }
.seg button { min-height: 44px; padding: 0 1rem; border: 0; background: transparent; color: var(--text); font: 500 1rem var(--sans); cursor: pointer; }
.seg button + button { border-left: 1px solid var(--rule-2); }
.seg button[aria-pressed="true"] { background: var(--primary); color: #fff; }

.sheet {
  display: grid; gap: 1rem 1.6rem; grid-template-columns: minmax(0, 1fr); background: var(--card); border: 1px solid var(--rule-2);
  border-left: 5px solid var(--primary); border-radius: var(--radius); padding: 1.1rem 1.3rem; margin-bottom: 1.1rem; box-shadow: 2px 2px 0 var(--rule);
}
.sheet-lab { font: 600 .78rem var(--mono); letter-spacing: .14em; text-transform: uppercase; color: var(--muted); margin: 0; }
.sheet-eq { overflow-x: auto; overflow-y: hidden; padding: .1rem 0; }
.sheet-eq .katex-display { margin: .15rem 0; text-align: left; }
.sheet-eq .katex { font-size: 1.9em; }
.sheet-eq .katex-display > .katex { text-align: left; }
.sheet-msg { display: flex; align-items: center; gap: .5rem; margin: .2rem 0 0; font: italic 400 1.15rem var(--serif); color: var(--green); }
:root[data-theme="dark"] .sheet-msg { color: #7fd685; }
.sheet-stats { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 0; margin: .3rem 0 0; border-top: 1px solid var(--rule); }
.sheet-stats div { padding: .55rem .5rem .1rem .7rem; border-right: 1px solid var(--rule); }
.sheet-stats div:first-child { padding-left: 0; }
.sheet-stats div:last-child { border-right: 0; }
.sheet-stats dt { font: 500 .85rem var(--mono); color: var(--muted); }
.sheet-stats dd { margin: 0; font: 600 1.3rem var(--mono); letter-spacing: -.01em; }
.sheet-plot { display: none; }
.sheet-note { grid-column: 1 / -1; margin: 0; }
@media (min-width: 760px) {
  .sheet { grid-template-columns: minmax(0, 1fr) 210px; align-items: center; }
  .sheet-plot { display: block; grid-row: 1 / span 2; grid-column: 2; }
  .sheet-plot svg { width: 100%; height: auto; display: block; }
}
.jump { display: flex; flex-wrap: wrap; gap: .3rem; align-items: center; margin: 0 0 1.1rem; }
.jump span { font: 500 .85rem var(--mono); letter-spacing: .1em; text-transform: uppercase; color: var(--muted); margin-right: .3rem; }
.jump a { min-height: 40px; display: inline-flex; align-items: center; justify-content: center; padding: 0 .65rem; border: 1px solid var(--rule-2); border-radius: 4px; background: var(--card); color: var(--text); text-decoration: none; font: 500 .85rem var(--mono); }
.jump a:hover { background: var(--primary); color: #fff; border-color: var(--primary); }

.rc { padding: 0; overflow: hidden; }
.rc-h { display: flex; align-items: center; gap: .4rem; padding: .3rem .6rem .3rem 0; flex-wrap: wrap; }
.rc-toggle {
  flex: 1; min-width: 200px; min-height: 56px; display: flex; align-items: center; gap: .75rem; text-align: left; border: 0; background: transparent;
  color: var(--text); font: 600 1.22rem/1.2 var(--serif); cursor: pointer; padding: .3rem 1rem;
}
.rc-num { font: 600 .82rem var(--mono); color: var(--accent); border: 1px solid var(--accent); border-radius: 4px; padding: .05rem .4rem; letter-spacing: .04em; flex: none; }
.rc-title { flex: 1; }
.chev { display: inline-flex; color: var(--muted); transition: transform .2s; }
.rc-toggle[aria-expanded="false"] .chev { transform: rotate(-90deg); }
.help-box { margin: 0 1rem .6rem; padding: .6rem .95rem; background: var(--note-bg); border-left: 3px solid var(--accent); border-radius: 0 6px 6px 0; }
.help-box p { margin: .2rem 0; }
.rc-body { padding: .4rem 1.1rem 1.1rem 1.4rem; border-top: 1px solid var(--rule); }

/* pasos: línea de tiempo con nodos numerados */
.steps { counter-reset: st; display: grid; grid-template-columns: minmax(0, 1fr); padding-top: .9rem; }
.step {
  counter-increment: st; position: relative; padding: 0 0 1.35rem 1.25rem; border-left: 2px solid var(--green-line); animation: fadein .3s ease;
}
.step:last-child { border-left-color: transparent; padding-bottom: .3rem; }
.step h4 { position: relative; font-size: 1.15rem; margin: 0 0 .5rem; min-height: 28px; padding-top: 1px; }
.step h4::before {
  content: counter(st); position: absolute; left: calc(-1.25rem - 15px); top: -1px; width: 28px; height: 28px; border-radius: 50%;
  background: var(--green); color: #fff; display: grid; place-items: center; font: 600 .85rem var(--mono); box-shadow: 0 0 0 4px var(--card);
}
.step-ctl { display: flex; flex-wrap: wrap; align-items: center; gap: .5rem; margin-top: .6rem; padding-top: .8rem; border-top: 1px dashed var(--rule-2); }
.step-count { font: 600 .9rem var(--mono); color: var(--green); margin-right: auto; letter-spacing: .04em; }
:root[data-theme="dark"] .step-count { color: #7fd685; }

.fx { margin: .55rem 0 .7rem; display: grid; grid-template-columns: minmax(0, 1fr); border: 1px solid var(--rule-2); border-radius: 6px; overflow: hidden; background: var(--card); }
.fx-row { display: grid; grid-template-columns: minmax(0, 1fr); align-items: center; padding: .1rem .85rem; overflow-x: auto; }
.fx-row + .fx-row { border-top: 1px solid var(--rule); }
.fx-cap { font: 600 .74rem var(--mono); text-transform: uppercase; letter-spacing: .12em; color: var(--muted); padding-top: .45rem; }
.fx-row.res { background: var(--green-bg); box-shadow: inset 4px 0 0 var(--green); }
.fx-row.res .fx-cap { color: var(--green); }
:root[data-theme="dark"] .fx-row.res .fx-cap { color: #7fd685; }
.fx .katex-display, .step .katex-display { margin: .3rem 0; overflow-x: auto; overflow-y: hidden; padding: .15rem 0; }
.katex { font-size: 1.08em; }
@media (min-width: 720px) {
  .fx-row { grid-template-columns: 104px minmax(0, 1fr); column-gap: .6rem; }
  .fx-cap { padding-top: 0; }
}

.chip { display: inline-flex; align-items: center; gap: .38rem; font: 600 .8rem var(--mono); letter-spacing: .04em; color: var(--text); white-space: nowrap; }
.chip::before { content: ""; width: .78em; height: .78em; border-radius: 2px; background: var(--c, var(--muted)); }
.chip.sst { --c: var(--sst); } .chip.ssr { --c: var(--ssr); } .chip.sse { --c: var(--sse); }
.cheer { display: flex; align-items: center; gap: .5rem; margin: .7rem 0 0; font: italic 400 1.08rem var(--serif); color: var(--green); }
:root[data-theme="dark"] .cheer { color: #7fd685; }
.decision { padding: .75rem 1rem; margin: .65rem 0; border: 1px solid var(--rule-2); border-left: 4px solid var(--primary); border-radius: 0 6px 6px 0; background: var(--card-2); font: 400 1.08rem/1.5 var(--serif); }
.more { margin-top: .8rem; border: 1px solid var(--rule-2); border-radius: 6px; background: var(--card); }
.more summary { min-height: 44px; display: flex; align-items: center; padding: 0 .95rem; font-weight: 500; cursor: pointer; color: var(--accent); }
.more-b { padding: 0 .95rem .7rem; }
.line-list { list-style: none; padding: 0; margin: .4rem 0; display: grid; gap: .3rem; }
.line-list label { display: flex; gap: .6rem; align-items: flex-start; padding: .35rem .2rem; cursor: pointer; }
.line-list input { margin-top: .15rem; }

.tbl { border-collapse: collapse; width: 100%; font: 400 .92rem var(--mono); }
.tbl th, .tbl td { padding: .42rem .7rem; border-bottom: 1px solid var(--rule); text-align: right; white-space: nowrap; }
.tbl th { font: 600 .82rem var(--sans); color: var(--muted); border-bottom: 2px solid var(--text); vertical-align: bottom; background: transparent; }
.tbl td:first-child, .tbl th:first-child { text-align: left; }
.tbl tfoot td { font-weight: 600; background: var(--green-bg); border-top: 2px solid var(--green); border-bottom: 0; }
.tbl.summary td, .tbl.summary th { text-align: left; white-space: normal; vertical-align: top; font-family: var(--sans); }
.tbl.summary td.num { white-space: nowrap; font: 600 .95rem var(--mono); }
.tbl.summary .katex { font-size: 1em; }

.chartbox { margin: .6rem 0 .4rem; border: 1px solid var(--rule-2); border-radius: 6px; overflow: hidden; background: var(--card); }
.chartbox figcaption { display: flex; align-items: center; justify-content: space-between; gap: .5rem; padding: .25rem .4rem .25rem .85rem; font: 600 .76rem var(--mono); letter-spacing: .1em; text-transform: uppercase; color: var(--muted); background: var(--card-2); border-bottom: 1px solid var(--rule-2); }
.chartbox figcaption .btn { text-transform: none; letter-spacing: 0; font-family: var(--sans); }
.chart-canvas { position: relative; height: 320px; padding: .4rem .5rem .2rem; }
.chart-canvas.panels-box { height: auto; display: grid; gap: .4rem; grid-template-columns: 1fr; }
.panel-cell { position: relative; height: 290px; }
@media (min-width: 1000px) { .chart-canvas.panels-box { grid-template-columns: repeat(3, 1fr); } }
@media (min-width: 720px) { .chart-canvas { height: 380px; } }
.pick-info { border-top: 1px dashed var(--rule-2); padding: .55rem .85rem .3rem; min-height: 64px; }
.pick-info .hint { color: var(--muted); font-style: italic; }
.pick p { margin: .1rem 0; }
.pick .katex-display { margin: .2rem 0; }
.graph-item { margin-bottom: 1.4rem; }
.caption { margin: 0 0 .2rem; color: var(--muted); }

.rmeter { margin: .9rem 0 1.4rem; padding-top: 1.8rem; }
.rm-track { position: relative; height: 14px; border-radius: 2px; background: linear-gradient(90deg, #ef6c00, #e6dfcf 50%, #00897b); border: 1px solid var(--rule-2); }
.rm-zero { position: absolute; left: 50%; top: -5px; bottom: -5px; width: 1px; background: var(--text); opacity: .55; }
.rm-mark { position: absolute; top: -7px; width: 5px; height: 28px; margin-left: -2px; border-radius: 1px; background: var(--text); box-shadow: 0 0 0 2px var(--card); }
.rm-mark span { position: absolute; bottom: 33px; left: 50%; transform: translateX(-50%); background: var(--text); color: var(--card); padding: .05rem .5rem; border-radius: 4px; font: 600 .85rem var(--mono); white-space: nowrap; }
.rm-scale { display: flex; justify-content: space-between; font: 400 .72rem var(--mono); color: var(--muted); margin-top: .35rem; }
.rm-zones { display: none; font-size: .7rem; color: var(--muted); margin-top: .1rem; }
.rm-zones span { text-align: center; flex: 1; }
.rm-zones span:nth-child(5) { flex: 2; }
.rm-dir { display: flex; justify-content: space-between; font: 500 .85rem var(--mono); margin-top: .3rem; }
@media (min-width: 600px) { .rm-zones { display: flex; } }
.cmp { display: grid; gap: .7rem; grid-template-columns: 1fr; }
@media (min-width: 640px) { .cmp { grid-template-columns: 1fr 1fr; } }
.cmp-c { border: 1px solid var(--rule-2); border-radius: 6px; padding: .6rem .95rem; background: var(--card-2); }
.cmp-c h5 { font-family: var(--mono); font-weight: 600; font-size: 1.05rem; }

.empty { text-align: center; padding: 2.4rem 1rem; background: var(--card); border: 1.5px dashed var(--rule-2); border-radius: var(--radius); }
.empty svg { color: var(--accent); margin-bottom: .4rem; }

/* ---------- tooltips y avisos ---------- */
.tip { border-bottom: 1.5px dotted var(--accent); cursor: help; }
.tip:focus-visible { background: var(--blue-bg); }
#tip {
  position: fixed; z-index: 120; left: 0; top: 0; background: var(--text); color: var(--paper); padding: .55rem .75rem; border-radius: 6px; font-size: .9rem; line-height: 1.45;
  box-shadow: 0 6px 24px rgba(0, 0, 0, .3); opacity: 0; pointer-events: none; transition: opacity .12s; max-width: 320px;
}
#tip.show { opacity: 1; }
#toast {
  position: fixed; left: 50%; bottom: calc(var(--nav-h) + 18px + env(safe-area-inset-bottom)); transform: translate(-50%, 20px); opacity: 0; z-index: 130;
  background: var(--text); color: var(--paper); padding: .7rem 1.1rem; border-radius: 6px; border-left: 4px solid var(--amber-b); box-shadow: 0 6px 24px rgba(0, 0, 0, .3);
  transition: all .25s; max-width: calc(100vw - 24px); pointer-events: none; font-weight: 500;
}
#toast.show { opacity: 1; transform: translate(-50%, 0); }
@media (min-width: 900px) { #toast { bottom: 24px; } }

/* ---------- aprender ---------- */
.ltabs { display: flex; gap: .2rem; overflow-x: auto; border-bottom: 1px solid var(--rule-2); margin-bottom: 1rem; }
.ltabs button { flex: none; min-height: 48px; padding: 0 1rem; border: 0; border-bottom: 3px solid transparent; background: transparent; color: var(--muted); font: 500 1rem var(--sans); cursor: pointer; margin-bottom: -1px; }
.ltabs button:hover { color: var(--text); }
.ltabs button[aria-selected="true"] { color: var(--accent); border-bottom-color: var(--accent); font-weight: 600; }
.search { margin-bottom: .8rem; }
.gl-grid { display: grid; gap: .6rem; grid-template-columns: 1fr; margin-bottom: 1.2rem; }
@media (min-width: 720px) { .gl-grid { grid-template-columns: 1fr 1fr; } }
.gl-item { display: flex; gap: .85rem; background: var(--card); border: 1px solid var(--rule-2); border-radius: 6px; padding: .7rem .9rem; align-items: flex-start; }
.gl-item p { margin: .2rem 0 0; }
.gl-k { flex: none; min-width: 62px; text-align: center; background: var(--card-2); border: 1px solid var(--rule-2); color: var(--accent); font: 600 1rem var(--mono); border-radius: 4px; padding: .3rem .4rem; overflow-wrap: anywhere; }
.gl-k.tex { font-family: var(--sans); color: var(--text); min-width: 90px; }
.faq { border-bottom: 1px solid var(--rule-2); }
.faq-i { border-top: 1px solid var(--rule-2); }
.faq-i summary { min-height: 52px; display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: .4rem .2rem; font: 600 1.12rem/1.3 var(--serif); cursor: pointer; list-style: none; }
.faq-i summary::-webkit-details-marker { display: none; }
.faq-i summary::after { content: "+"; font: 400 1.5rem var(--mono); color: var(--accent); flex: none; }
.faq-i[open] summary::after { content: "−"; }
.faq-i summary p { margin: 0; }
.faq-a { padding: 0 .2rem .7rem; max-width: 44rem; }
.fm { display: grid; grid-template-columns: 1fr; padding: .35rem 0; border-bottom: 1px solid var(--rule); }
.fm:last-child { border-bottom: 0; }
.fm-n { font: 600 .82rem var(--mono); letter-spacing: .06em; text-transform: uppercase; color: var(--muted); }
.fm .katex-display { margin: .2rem 0; overflow-x: auto; overflow-y: hidden; }
.care-grid { display: grid; gap: .9rem; grid-template-columns: 1fr; }
@media (min-width: 720px) { .care-grid { grid-template-columns: 1fr 1fr; } }
.care-i { width: 44px; height: 44px; display: grid; place-items: center; border: 1px solid var(--accent); border-radius: 6px; color: var(--accent); margin-bottom: .5rem; }
.care-i svg { width: 24px; height: 24px; }
.foot { margin-top: 1.6rem; }

/* ---------- diálogos ---------- */
dialog { border: 1px solid var(--rule-2); border-radius: 10px; padding: 1.4rem 1.5rem; max-width: min(580px, calc(100vw - 24px)); width: 100%; background: var(--card); color: var(--text); box-shadow: 0 24px 60px rgba(0, 0, 0, .4); }
dialog::backdrop { background: rgba(12, 18, 34, .6); }
dialog textarea { min-height: 150px; resize: vertical; font-family: var(--mono); }
dialog h2 { font-size: 1.6rem; }
dialog h2 em { font-style: italic; font-weight: 500; color: var(--accent); }
.kicker-line { font: 600 .78rem var(--mono); letter-spacing: .16em; text-transform: uppercase; color: var(--muted); margin: 0 0 .3rem; }
.welcome { list-style: none; padding: 0; margin: .8rem 0; display: grid; gap: .3rem; }
.welcome li { display: grid; grid-template-columns: 44px 1fr; gap: .7rem; align-items: start; padding: .55rem 0; border-top: 1px solid var(--rule); }
.welcome li:first-child { border-top: 0; }
.w-ic { font: italic 500 2.3rem/1 var(--serif); color: var(--accent); text-align: center; }
.welcome strong { font: 600 1.1rem var(--serif); }
.welcome p { margin: .1rem 0 0; color: var(--muted); }

/* ---------- celular: letra mínima de 16 px y blancos táctiles de 44 px ---------- */
@media (max-width: 899px) {
  .small, .tbl, .field, .opt, .caption, .rm-dir, .faq-a, .gl-item, .sheet-stats dt { font-size: 1rem; }
  .fx-cap { font-size: .85rem; }
  .jump a { min-height: 44px; min-width: 44px; font-size: .95rem; }
  .step-count, .btn.small { font-size: 1rem; }
  .rm-scale, .rm-zones { font-size: .8rem; }
  h2 { font-size: 1.75rem; }
  .rc-body { padding-left: 1.2rem; }
  .sheet-eq .katex { font-size: 1.55em; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; scroll-behavior: auto !important; }
}

/* ---------- impresión / PDF ---------- */
@media print {
  @page { margin: 14mm; }
  :root, :root[data-theme="dark"] {
    --paper: #fff; --bg: #fff; --card: #fff; --card-2: #f4f1ea; --text: #111; --muted: #444; --grid: #ddd; --rule: #ccc; --rule-2: #999; --border: #bbb; --accent: #1f3864;
    --blue-bg: #eef3fb; --note-bg: #f1f3f7; --green-bg: #eef7ee; --amber-bg: #fff6dc; --red-bg: #fdeeee; --link: #1a4fa8; --gridline: transparent;
  }
  body { padding: 0 !important; font-size: 11pt; background: #fff; }
  .topbar, .nav, #toast, #tip, .no-print, .step-ctl, .help-btn, .png-btn, .jump, .btn-row, .chev { display: none !important; }
  main { padding: 0; max-width: none; }
  .view { animation: none; }
  #view-data, #view-graphs, #view-learn { display: none !important; }
  #view-results { display: block !important; }
  .print-only { display: block; margin-bottom: 1rem; }
  .card, .step, .chartbox, .fx, .interp, .warn, .sheet { box-shadow: none; break-inside: avoid; }
  .rc-body { display: block !important; }
  .rc-body[hidden], .step[hidden] { display: block !important; }
  .help-box, .help-box[hidden] { display: none !important; }
  .sheet-plot { display: block; }
  .chip, .rc-num, .step h4::before, .gl-k, .rm-track, .tbl tfoot td, .fx-row.res, .interp, .decision { -webkit-print-color-adjust: exact; print-color-adjust: exact; }
  .rc { break-inside: auto; }
  .tip { border-bottom: 0; }
  .chart-canvas { height: 300px; }
  .chart-canvas.panels-box { grid-template-columns: 1fr; }
}

@media (max-width: 519px) {
  .sheet-stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .sheet-stats div { padding: .5rem .5rem .4rem .8rem; border-bottom: 1px solid var(--rule); }
  .sheet-stats div:nth-child(odd) { padding-left: 0; }
  .sheet-stats div:nth-child(even) { border-right: 0; }
  .sheet-stats div:nth-child(n + 3) { border-bottom: 0; }
}

@media (max-width: 519px) {
  #view-data .btn-row .btn { flex: 1 1 calc(50% - .5rem); padding-left: .6rem; padding-right: .6rem; }
  #view-data .btn-row #btn-example { flex-basis: 100%; }
  #view-data .btn-row #addRow { flex-basis: 100%; }
}

/* ---------- carga de datos en el celular ---------- */
.data-tbl input.cell.bad { border-color: var(--sse); background: var(--red-bg); box-shadow: inset 3px 0 0 var(--sse); }
.action-bar, .kbbar { display: none; }
.kbbar[hidden] { display: none !important; }
@media (max-width: 899px) {
  body.on-data { padding-bottom: calc(var(--nav-h) + 84px + env(safe-area-inset-bottom)); }
  body.on-data .action-bar {
    display: flex; align-items: center; justify-content: space-between; gap: .75rem; position: fixed; z-index: 44; left: 0; right: 0;
    bottom: calc(var(--nav-h) + env(safe-area-inset-bottom)); padding: .55rem .8rem; background: var(--card); border-top: 1px solid var(--rule-2);
    box-shadow: 0 -6px 14px -10px rgba(0, 0, 0, .35);
  }
  body.on-data.kb-open .action-bar { display: none; }
  .ab-status { display: flex; align-items: center; gap: .5rem; font: 400 1rem var(--sans); color: var(--muted); min-width: 0; }
  .ab-status.ok { color: var(--green); }
  :root[data-theme="dark"] .ab-status.ok { color: #7fd685; }
  .ab-status strong { font-family: var(--mono); }
  .action-bar .btn { flex: none; }
  body.kb-open { padding-bottom: 130px; }
  .kbbar {
    display: flex; position: fixed; z-index: 70; left: 0; right: 0; bottom: 0; gap: .35rem; padding: .4rem .5rem; background: var(--card-2);
    border-top: 1px solid var(--rule-2); box-shadow: 0 -6px 14px -10px rgba(0, 0, 0, .4);
  }
  .kbbar button {
    flex: 1 1 0; min-width: 44px; min-height: 46px; border: 1px solid var(--rule-2); border-radius: 6px; background: var(--card); color: var(--text);
    font: 600 1.35rem var(--mono); display: inline-flex; align-items: center; justify-content: center; gap: .4rem; cursor: pointer; padding: 0 .3rem;
  }
  .kbbar button:active { background: var(--card-2); }
  .kbbar .kb-next { flex: 2.4 1 0; font: 600 1rem var(--sans); background: var(--primary); color: #fff; border-color: var(--primary); }
  .kbbar .flip svg { transform: scaleX(-1); }
}
@media (max-width: 899px) {
  body.on-data #toast { bottom: calc(var(--nav-h) + 92px + env(safe-area-inset-bottom)); }
  body.kb-open #toast { bottom: 76px; }
}
@media (max-width: 899px) {
  body.on-data #calc { display: none; }
}

/* ---------- navegación con 5 secciones, ejemplos y modo práctica ---------- */
.nav { grid-template-columns: repeat(5, 1fr); }
.nav button { font-size: .78rem; }
@media (min-width: 900px) { .nav { grid-template-columns: 1fr; } .nav button { font-size: 1.02rem; } }
.author { font-family: var(--serif); font-style: italic; }
.author strong { font-style: normal; }
.nav-foot strong { font-style: normal; font-family: var(--sans); font-weight: 600; color: var(--text); }

.ex-list { list-style: none; margin: .8rem 0; padding: 0; display: grid; gap: .7rem; }
.ex-item { border: 1px solid var(--rule-2); border-radius: 6px; padding: .75rem .95rem .85rem; background: var(--card-2); }
.ex-item h3 { font-size: 1.15rem; margin: 0; }
.ex-item p { margin: .3rem 0; }
.ex-tag { display: inline-block; font: 600 .74rem var(--mono); letter-spacing: .1em; text-transform: uppercase; color: var(--accent); border: 1px solid var(--accent); border-radius: 4px; padding: 0 .4rem; margin-bottom: .3rem; }
.ex-learn { color: var(--muted); }
dialog#dlg-examples { max-width: min(640px, calc(100vw - 24px)); max-height: calc(100vh - 32px); overflow-y: auto; }

.p-levels { display: grid; gap: .5rem; grid-template-columns: 1fr; margin: .8rem 0; }
@media (min-width: 640px) { .p-levels { grid-template-columns: repeat(3, 1fr); } }
.lvl { display: flex; flex-direction: column; align-items: flex-start; gap: .15rem; text-align: left; padding: .65rem .85rem; border: 1px solid var(--rule-2); border-radius: 6px; background: var(--card); color: var(--text); cursor: pointer; font: 400 1rem var(--sans); }
.lvl:hover { border-color: var(--text); }
.lvl[aria-pressed="true"] { background: var(--primary); color: #fff; border-color: var(--primary); box-shadow: 0 2px 0 rgba(0, 0, 0, .3); }
.lvl-n { font: 600 .75rem var(--mono); letter-spacing: .12em; text-transform: uppercase; opacity: .8; }
.lvl-t { font: 600 1.1rem var(--serif); }
.lvl-d { font-size: .95rem; opacity: .85; }
.p-stats { margin-bottom: 0; }
.p-intro { font: 400 1.12rem/1.5 var(--serif); }
.p-data { max-width: 460px; }
.p-given { margin: .9rem 0; padding: .7rem .95rem; border: 1px solid var(--rule-2); border-left: 4px solid var(--accent); border-radius: 0 6px 6px 0; background: var(--blue-bg); }
.p-lab { margin: 0 0 .3rem; font: 600 .75rem var(--mono); letter-spacing: .12em; text-transform: uppercase; color: var(--accent); }
.p-given dl { display: flex; flex-wrap: wrap; gap: .4rem 1.2rem; margin: 0; }
.p-given dl div { display: flex; gap: .45rem; align-items: baseline; }
.p-given dt { margin: 0; }
.p-given dd { margin: 0; font: 600 1rem var(--mono); }
.p-h { margin-top: 1.1rem; }
.p-qs { list-style: none; margin: .4rem 0 .8rem; padding: 0; display: grid; gap: .5rem; }
.q { display: grid; grid-template-columns: minmax(0, 1fr); gap: .35rem .8rem; padding: .6rem .8rem; border: 1px solid var(--rule-2); border-left-width: 4px; border-radius: 6px; background: var(--card); }
.q.ok { border-left-color: var(--green); background: var(--green-bg); }
.q.bad { border-left-color: var(--sse); background: var(--red-bg); }
.q-l { display: flex; align-items: baseline; gap: .7rem; flex-wrap: wrap; }
.q-sym { min-width: 3.4rem; }
.q-name { color: var(--muted); }
.q-in { display: flex; align-items: center; gap: .7rem; flex-wrap: wrap; }
.q-in input.ans { width: 9.5rem; max-width: 100%; text-align: right; font-family: var(--mono); font-size: 1.05rem; }
.q-st { display: inline-flex; align-items: center; gap: .35rem; font-weight: 500; }
.q.ok .q-st { color: var(--green); }
.q.bad .q-st { color: var(--sse); }
:root[data-theme="dark"] .q.ok .q-st { color: #7fd685; }
:root[data-theme="dark"] .q.bad .q-st { color: #ff8a80; }
.q-st .muted { color: var(--muted); }
.q-radios { display: flex; gap: 1.1rem; flex-wrap: wrap; }
.q-radios label { display: flex; align-items: center; gap: .5rem; min-height: 44px; cursor: pointer; }
.q-fb { border-top: 1px dashed var(--rule-2); padding-top: .4rem; }
.q-fb p { margin: .2rem 0; }
.q-fb .katex-display { margin: .3rem 0; overflow-x: auto; overflow-y: hidden; }
.p-score { display: flex; align-items: center; gap: 1rem; padding: .8rem 1rem; margin: .4rem 0; border: 1px solid var(--rule-2); border-left: 4px solid var(--primary); border-radius: 0 6px 6px 0; background: var(--card-2); }
.p-score.perfect { border-left-color: var(--green); background: var(--green-bg); }
.p-score p { margin: 0; font: 400 1.08rem var(--serif); }
.p-score-n { font: 600 2rem var(--mono); line-height: 1; white-space: nowrap; }
.p-score-n span { font-size: 1rem; color: var(--muted); }
@media (min-width: 720px) { .q { grid-template-columns: minmax(0, 1fr) auto; align-items: center; } .q-fb { grid-column: 1 / -1; } }
@media (max-width: 899px) { .lvl-d { font-size: 1rem; } .ex-tag { font-size: .8rem; } }
.p-data th, .p-data td { white-space: normal; }
.p-data th:not(:first-child), .p-data td:not(:first-child) { text-align: right; }
@media (max-width: 899px) {
  .kicker-line, .p-lab, .sheet-lab, .lvl-n, .ex-tag, .q-name, .tbl.summary td.num { font-size: 1rem; }
  .kicker-line, .p-lab, .sheet-lab, .lvl-n { letter-spacing: .06em; }
}
@media (max-width: 899px) {
  .kicker, .rc-num, .chip, .fx-cap, .ex-tag, .jump span { font-size: 1rem; }
  .fx-cap, .kicker { letter-spacing: .06em; }
}
@media (max-width: 899px) {
  .tbl th, .data-tbl th, .chartbox figcaption, .interp .lab, .jump a, .rm-mark span, .sheet-stats dt sub, .step-count { font-size: 1rem; }
  .chartbox figcaption, .interp .lab { letter-spacing: .05em; }
}

/* ---------- modo pizarrón (para proyectar en clase) ---------- */
body.board-open { overflow: hidden; }
.board {
  position: fixed; inset: 0; z-index: 300; display: flex; flex-direction: column; outline: none;
  font-size: calc(var(--bs, 1) * clamp(17px, 0.9vw + 11px, 30px)); color: var(--text); background-color: var(--paper);
}
.board.chalk {
  --paper: #0f2a23; --card: #15352c; --card-2: #1c4237; --text: #f4f1e4; --muted: #b9c8c0; --rule: rgba(244, 241, 228, .2); --rule-2: rgba(244, 241, 228, .42);
  --accent: #ffd76a; --link: #9cc9ff; --green: #8be0a0; --green-line: rgba(139, 224, 160, .45); --green-bg: rgba(255, 215, 106, .12);
  --blue-b: #9cc9ff; --blue-bg: rgba(156, 201, 255, .13); --amber-bg: rgba(255, 215, 106, .16); --amber-b: #ffd76a; --note-bg: rgba(255, 255, 255, .08);
  --red-bg: rgba(255, 122, 114, .16); --sst: #d6a3f0; --ssr: #82b8ff; --sse: #ff8f88; --primary: #ffd76a; --primary-t: #1a2b24; --grid: rgba(244, 241, 228, .16);
  background-image: radial-gradient(ellipse at 25% 15%, rgba(255, 255, 255, .07), transparent 55%), radial-gradient(ellipse at 85% 95%, rgba(255, 255, 255, .05), transparent 50%);
}
.board.paper {
  --paper: #fbf8ef; --card: #fffdf7; --card-2: #efe9db; --text: #1a2036; --muted: #576078; --rule: #d9d1be; --rule-2: #b7ad96; --accent: #1f3864; --link: #1a4fa8;
  --green: #2e7d32; --green-line: rgba(46, 125, 50, .38); --green-bg: #e8f1e4; --blue-b: #1f3864; --blue-bg: rgba(31, 56, 100, .065); --amber-bg: #fbf0cd; --amber-b: #c88a00;
  --note-bg: #ece6d8; --red-bg: #f7e3df; --sst: #7b3fa0; --ssr: #1e6fd9; --sse: #c62828; --primary: #1f3864; --primary-t: #fff; --grid: #e3dbca;
}
.b-progress { height: 5px; background: var(--rule); flex: none; }
#b-bar { display: block; height: 100%; width: 0; background: var(--accent); transition: width .3s ease; }
.b-top { display: flex; justify-content: space-between; align-items: center; gap: 1rem; padding: .6rem 1rem; flex: none; transition: opacity .5s; }
.b-crumb { display: flex; flex-wrap: wrap; gap: .3rem 1.4rem; font: 500 max(1rem, .62em) var(--mono); color: var(--muted); min-width: 0; }
#b-sec { color: var(--text); }
.b-tools { display: flex; gap: .4rem; flex: none; }
.b-tools button { min-width: 44px; min-height: 44px; padding: 0 .6rem; border: 1px solid var(--rule-2); border-radius: 6px; background: transparent; color: var(--text); font: 600 1rem var(--sans); cursor: pointer; display: inline-flex; align-items: center; justify-content: center; }
.b-tools button:hover, .b-tools button[aria-expanded="true"] { background: var(--card-2); border-color: var(--accent); }
.b-stage { flex: 1; min-height: 0; display: flex; justify-content: center; padding: 0 clamp(1rem, 4vw, 4.5rem); }
.b-slide { width: 100%; max-width: 1500px; overflow-y: auto; padding: .6em 0 1.5em; display: flex; flex-direction: column; animation: bfade .35s ease; }
.b-slide > :first-child { margin-top: auto; }
.b-slide > :last-child { margin-bottom: auto; }
@keyframes bfade { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.b-nav { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: .6rem 1rem calc(.6rem + env(safe-area-inset-bottom)); flex: none; transition: opacity .5s; }
.b-nav .btn { min-height: 52px; min-width: 9.5rem; font-size: 1.05rem; }
.b-nav .btn:disabled { opacity: .3; }
.b-nav .btn.primary { color: var(--primary-t); }
.b-keys { display: none; font: 400 .8rem var(--mono); color: var(--muted); }
@media (min-width: 900px) { .b-keys { display: block; } }
kbd { font: 500 .85em var(--mono); border: 1px solid var(--rule-2); border-bottom-width: 2px; border-radius: 4px; padding: 0 .35em; background: var(--card); }
.flip svg { transform: scaleX(-1); }
.board.idle .b-top, .board.idle .b-nav { opacity: .07; }
.board.idle { cursor: none; }

.b-kick { margin: 0 0 .35em; font: 500 .6em var(--mono); letter-spacing: .14em; text-transform: uppercase; color: var(--muted); }
.b-kick .b-num { margin-right: .5em; }
.b-num { color: var(--accent); border: 1px solid var(--accent); border-radius: 4px; padding: 0 .4em; font-family: var(--mono); font-weight: 600; letter-spacing: .04em; }
.b-step { font: 600 1.75em/1.15 var(--serif); margin: 0 0 .5em; color: var(--text); }
.b-step .chip { font-size: .5em; vertical-align: middle; }
.b-body { font-size: 1em; }
.b-body p { margin: .4em 0 .6em; }
.b-body .katex { font-size: 1.28em; }
.b-body .katex-display { margin: .35em 0; overflow-x: auto; overflow-y: hidden; }
.b-body .fx { border-color: var(--rule-2); background: transparent; }
.b-body .fx-row { grid-template-columns: minmax(0, 1fr); padding: .15em .9em; }
.b-body .fx-cap { font-size: .55em; color: var(--muted); }
@media (min-width: 900px) { .b-body .fx-row { grid-template-columns: 8.5em minmax(0, 1fr); } }
.b-body .fx-row.res { background: rgba(255, 215, 106, .14); box-shadow: inset .3em 0 0 var(--accent); }
.board.paper .b-body .fx-row.res { background: var(--green-bg); box-shadow: inset .3em 0 0 var(--green); }
.b-body .fx-row.res .fx-cap { color: var(--accent); }
.board.paper .b-body .fx-row.res .fx-cap { color: var(--green); }
.b-body .interp, .b-body .warn, .b-body .note, .b-body .decision { font-size: .95em; }
.b-body .decision { font-size: 1.05em; }
.b-body .tbl { font-size: .8em; }
.b-body .tbl td, .b-body .tbl th { padding: .35em .7em; }
.b-body .cheer { font-size: 1.1em; }
.b-body .rmeter { font-size: .9em; }
.b-body .cmp-c { background: var(--card-2); }
.b-body .png-btn { display: none; }
.b-body .step-ctl { display: none; }
.b-body .more { display: none; }
.b-body .line-list label, .b-body .line-list li { font-size: 1em; }
.frag { transition: opacity .4s ease, transform .4s ease; }
.frag.hide { opacity: 0; transform: translateY(10px); pointer-events: none; }

/* los gráficos siempre sobre un panel claro: conservan sus colores fijos (SST violeta, SSR azul, SSE rojo) */
.board .chartbox {
  --card: #fbf8ef; --card-2: #efe9db; --text: #1a2036; --muted: #576078; --grid: #e3dbca; --rule: #d9d1be; --rule-2: #b7ad96; --accent: #1f3864;
  --sst: #7b3fa0; --ssr: #1e6fd9; --sse: #c62828; --green: #2e7d32; --green-bg: #e8f1e4; --blue-bg: rgba(31, 56, 100, .065);
  background: var(--card); color: var(--text); border-color: var(--rule-2); font-size: .8em;
}
.b-body .chart-canvas { height: min(56vh, 640px); }
.b-body .chart-canvas.panels-box { height: auto; }
.b-body .panel-cell { height: min(44vh, 460px); }
@media (min-width: 1000px) { .b-body .chart-canvas.panels-box { grid-template-columns: repeat(3, 1fr); } }

.k-title, .k-intro { justify-content: center; }
.b-title { display: flex; flex-direction: column; align-items: flex-start; gap: .4em; }
.b-title .b-num { font-size: .9em; }
.b-title .b-num.big, .b-title > .b-num { font-size: 1.2em; }
.b-title h2 { font: 600 clamp(2rem, 3.4em, 5rem)/1.05 var(--serif); color: var(--text); margin: .1em 0 .2em; letter-spacing: -.01em; }
.b-title h2 em { font-style: italic; font-weight: 500; color: var(--accent); }
.b-help { max-width: 34em; color: var(--muted); font-size: 1.05em; }
.b-help p { margin: .3em 0; }
.b-data { max-width: 100%; margin: .6em 0; }
.b-data .tbl { font-size: .75em; }
.b-data .tbl th { text-align: left; white-space: nowrap; }
.b-facts { display: flex; flex-wrap: wrap; gap: .3em 1.6em; font: 400 .9em var(--mono); color: var(--muted); margin: .3em 0; }
.b-facts strong { color: var(--text); font-weight: 600; }
.b-hint { color: var(--muted); font-size: .8em; margin-top: 1em; }
.b-author { font: italic 400 1em var(--serif); color: var(--accent); margin: .4em 0 0; }

.b-index { position: absolute; top: 0; right: 0; bottom: 0; width: min(30em, 92vw); z-index: 5; overflow-y: auto; padding: 1.2em 1em; background: var(--card); border-left: 1px solid var(--rule-2); box-shadow: -10px 0 30px rgba(0, 0, 0, .35); font-size: .8em; }
.b-index h2 { font: 600 1.3em var(--serif); margin-bottom: .6em; color: var(--text); }
.b-index ol { list-style: none; margin: 0; padding: 0; display: grid; gap: .2em; }
.b-index button { width: 100%; min-height: 44px; text-align: left; padding: .4em .7em; border: 1px solid transparent; border-radius: 6px; background: transparent; color: var(--text); font: 400 1em var(--sans); cursor: pointer; }
.b-index button:hover { background: var(--card-2); }
.b-index button[aria-current="true"] { background: var(--card-2); border-color: var(--accent); color: var(--accent); font-weight: 600; }

@media (max-width: 899px) {
  .b-top { padding: .5rem .6rem; }
  .b-nav .btn { min-width: 0; flex: 1; }
  .b-tools button { min-width: 44px; }
  .b-step { font-size: 1.5em; }
}
@media print { .board { display: none !important; } }
@media (prefers-reduced-motion: reduce) { .b-slide, .frag { animation: none; transition: none; } }
.board-btn { padding-left: .6rem; padding-right: .6rem; }
.b-body .chart-canvas { height: max(220px, min(43vh, 600px)); }
.b-body .panel-cell { height: max(200px, min(39vh, 440px)); }
.b-body .pick-info { min-height: 0; }
@media (max-width: 899px) {
  .b-top { flex-wrap: wrap; row-gap: .3rem; }
  .b-tools { order: 1; margin-left: auto; }
  .b-crumb { order: 2; flex: 1 1 100%; flex-wrap: nowrap; gap: .8rem; }
  #b-sec { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; min-width: 0; }
  #b-pos { flex: none; }
}

/* ---------- 5.15 excluir puntos ---------- */
.excl-tbl td.chk, .excl-tbl th:first-child { text-align: center; }
.excl-tbl td.chk label { display: flex; align-items: center; justify-content: center; min-width: 44px; min-height: 44px; cursor: pointer; }
.excl-tbl td.chk input { width: 22px; height: 22px; }
.excl-tbl tr.infl td { background: var(--amber-bg); }
.excl-tbl tr.off td:not(.chk) { opacity: .5; text-decoration: line-through; }
.excl-tbl td, .excl-tbl th { text-align: right; }
.excl-tbl td:first-child, .excl-tbl th:first-child { text-align: center; }
.tagx { display: inline-block; font: 600 .78rem var(--mono); letter-spacing: .06em; text-transform: uppercase; color: var(--amber-t); border: 1px solid var(--amber-b); border-radius: 4px; padding: 0 .4rem; white-space: nowrap; }
.cmp-t td:not(:first-child), .cmp-t th:not(:first-child) { text-align: right; }
.cmp-t td:first-child { text-align: left; font-family: var(--sans); }
.b-body .excl-apply { display: none; }
@media (max-width: 899px) { .tagx { font-size: 1rem; } }
.excl-tbl th, .excl-tbl td { padding: .4rem .5rem; white-space: normal; }
@media (max-width: 640px) { .excl-tbl .c-res, .excl-tbl .c-tag { display: none; } }
@media (max-width: 640px) { .excl-tbl th, .excl-tbl td { padding: .35rem .3rem; } }

/* ---------- ejercicios asignados ---------- */
dialog#dlg-assign { max-width: min(640px, calc(100vw - 24px)); max-height: calc(100vh - 32px); overflow-y: auto; }
dialog#dlg-assign .field { margin: .7rem 0; }
dialog#dlg-assign textarea { font-family: var(--sans); }
.as-qs-box { border: 1px solid var(--rule-2); border-radius: 6px; padding: .3rem .8rem .5rem; }
.as-qs-box legend { padding: 0 .4rem; font-weight: 500; }
#as-questions { display: grid; grid-template-columns: 1fr; }
@media (min-width: 560px) { #as-questions { grid-template-columns: 1fr 1fr; column-gap: 1rem; } }
.p-assigned h3 { font-size: 1.5rem; margin-bottom: .2rem; }
.p-name { margin: .8rem 0; max-width: 28rem; }
@media (max-width: 899px) { .as-qs-box .small { font-size: 1rem; } }

/* ---------- código QR ---------- */
dialog#dlg-qr {
  --card: #fdfbf5; --card-2: #efe9db; --text: #1a2036; --muted: #576078; --rule: #d9d1be; --rule-2: #b7ad96; --accent: #1f3864; --primary: #1f3864; --primary-t: #fff;
  width: 100vw; height: 100vh; height: 100dvh; max-width: none; max-height: none; margin: 0; padding: 1rem; border: 0; border-radius: 0; box-shadow: none; background: #fff; color: #1a2036;
}
dialog#dlg-qr[open] { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: .5rem; text-align: center; overflow-y: auto; }
.qr-kick { margin: 0; font: 600 .85rem var(--mono); letter-spacing: .14em; text-transform: uppercase; color: #576078; }
#qr-title { font: 600 clamp(1.5rem, 4vmin, 2.6rem)/1.15 var(--serif); margin: 0; color: #1a2036; }
.qr-img { width: min(70vmin, 700px); max-width: 100%; margin: .3rem auto; border: 1px solid #d9d1be; }
.qr-img svg { display: block; width: 100%; height: auto; }
.qr-link { margin: 0; max-width: 46rem; font: 400 .85rem var(--mono); color: #576078; overflow-wrap: anywhere; }
.qr-note { margin: 0; max-width: 40rem; font: 400 1.05rem var(--serif); color: #1a2036; }
dialog#dlg-qr .btn-row { margin-top: .4rem; }
@media (max-width: 899px) { .qr-kick, .qr-link { font-size: 1rem; } }
@media print { dialog#dlg-qr[open] { display: flex; } .qr-img { width: 12cm; } dialog#dlg-qr .btn-row { display: none; } }

/* ---------- gráficos de normalidad ---------- */
.chart-pair { display: grid; grid-template-columns: minmax(0, 1fr); gap: .6rem; margin: .5rem 0; }
.chart-pair .chartbox { margin: 0; }
@media (min-width: 900px) { .chart-pair { grid-template-columns: 1fr 1fr; } .chart-pair .chart-canvas { height: 320px; } }
.b-body .chart-pair .chart-canvas { height: max(220px, min(40vh, 460px)); }
@media (max-width: 899px) {
  .rm-scale { font-size: 1rem; }
  .rm-scale span:not(:first-child):not(:last-child):not(:nth-child(6)) { display: none; }
}