/* Ingeniero desde 0 — estilos
   Lenguaje visual: banco de trabajo de electrónica. Verde de placa (PCB), cobre de las pistas,
   ámbar de señal. Tipografía técnica (Bahnschrift, la DIN de Windows) para títulos y etiquetas. */

:root {
  --bg: #f5f3ec;
  --surface: #fffdf8;
  --surface-2: #efece2;
  --ink: #18211c;
  --muted: #5a665f;
  --line: #dcd7c8;
  --accent: #0b7a53;
  --accent-ink: #ffffff;
  --accent-soft: #dff0e7;
  --copper: #b05f24;
  --copper-soft: #f6e6d8;
  --signal: #ffd166;
  --signal-ink: #7a5600;
  --signal-soft: #fdf1cf;
  --danger: #b8351f;
  --danger-soft: #fbe3de;
  --info: #23619f;
  --info-soft: #e0ecf8;
  --code-bg: #14201a;
  --code-ink: #dbe7df;
  --shadow: 0 1px 2px rgba(24, 33, 28, .06), 0 8px 24px -12px rgba(24, 33, 28, .18);
  --display: Bahnschrift, "DIN Alternate", "Segoe UI Semibold", "Segoe UI", system-ui, sans-serif;
  --body: "Segoe UI", system-ui, -apple-system, Roboto, "Helvetica Neue", sans-serif;
  --mono: "Cascadia Code", "Cascadia Mono", Consolas, ui-monospace, "SF Mono", Menlo, monospace;
  --top: 58px;
  --side: 310px;
}
:root[data-theme="dark"] {
  --bg: #0d1411;
  --surface: #141d18;
  --surface-2: #1a2620;
  --ink: #e4ece7;
  --muted: #98a89f;
  --line: #27362e;
  --accent: #3ddc97;
  --accent-ink: #062014;
  --accent-soft: #143326;
  --copper: #eb9a60;
  --copper-soft: #33241a;
  --signal: #ffd166;
  --signal-ink: #ffd166;
  --signal-soft: #332b14;
  --danger: #ff8a73;
  --danger-soft: #3a1c17;
  --info: #7db8f2;
  --info-soft: #162838;
  --code-bg: #0a100d;
  --code-ink: #d5e2da;
  --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 10px 28px -14px rgba(0, 0, 0, .7);
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-padding-top: calc(var(--top) + 16px); -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 17px/1.65 var(--body);
}
h1, h2, h3, h4 { font-family: var(--display); line-height: 1.15; margin: 0; text-wrap: balance; letter-spacing: -.005em; }
p { margin: 0 0 1em; }
a { color: var(--accent); text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--signal); outline-offset: 2px; border-radius: 4px; }
::selection { background: var(--signal); color: #1c1600; }
[hidden] { display: none !important; }
kbd { font: 12px var(--mono); border: 1px solid var(--line); border-bottom-width: 2px; border-radius: 4px; padding: 0 5px; color: var(--muted); }
.skip { position: absolute; left: -999px; top: 8px; background: var(--accent); color: var(--accent-ink); padding: 8px 14px; border-radius: 6px; z-index: 100; }
.skip:focus { left: 8px; }

.label, .eyebrow {
  font: 600 12px/1.2 var(--mono); letter-spacing: .09em; text-transform: uppercase; margin: 0 0 .6em; color: var(--muted);
}
.eyebrow { color: var(--copper); }

/* ---------- Barra superior ---------- */
.topbar {
  position: sticky; top: 0; z-index: 30; height: var(--top);
  display: flex; align-items: center; gap: 14px; padding: 0 18px;
  background: color-mix(in srgb, var(--bg) 88%, transparent); -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font: 500 18px var(--display); white-space: nowrap; }
.brand b { color: var(--accent); font-weight: 700; }
.brand-mark { display: grid; }
.topnav { display: flex; gap: 2px; margin-left: 10px; }
.topnav a { color: var(--muted); text-decoration: none; padding: 6px 12px; border-radius: 6px; font-size: 15px; }
.topnav a:hover { color: var(--ink); background: var(--surface-2); }
.topnav a.on { color: var(--ink); font-weight: 600; box-shadow: inset 0 -2px 0 var(--accent); border-radius: 6px 6px 0 0; }
.icon-btn { display: grid; place-items: center; width: 38px; height: 38px; border: 1px solid transparent; border-radius: 8px; background: none; color: var(--ink); cursor: pointer; }
.icon-btn:hover { background: var(--surface-2); border-color: var(--line); }
.menu-btn { display: none; }

.search { position: relative; margin-left: auto; display: flex; align-items: center; gap: 8px; width: min(320px, 34vw); padding: 0 10px; height: 38px; background: var(--surface); border: 1px solid var(--line); border-radius: 8px; color: var(--muted); }
.search:focus-within { border-color: var(--accent); }
.search input { flex: 1; min-width: 0; border: 0; background: none; color: var(--ink); font: inherit; font-size: 15px; outline: none; }
.search input::placeholder { color: var(--muted); }
.search-results { position: absolute; top: 44px; right: 0; width: min(440px, 92vw); max-height: 70vh; overflow: auto; background: var(--surface); border: 1px solid var(--line); border-radius: 10px; box-shadow: var(--shadow); padding: 6px; }
.search-results a { display: block; padding: 9px 11px; border-radius: 7px; text-decoration: none; color: var(--ink); }
.search-results a:hover, .search-results a:focus { background: var(--surface-2); }
.search-results b { display: block; font-size: 15px; }
.search-results small { font: 11px var(--mono); text-transform: uppercase; letter-spacing: .06em; color: var(--copper); }
.search-results span { display: block; font-size: 13px; color: var(--muted); line-height: 1.4; }
.empty { color: var(--muted); padding: 12px; margin: 0; font-size: 15px; }

.progress-chip { display: flex; align-items: center; gap: 7px; text-decoration: none; color: var(--ink); font: 600 13px var(--mono); padding: 4px 10px 4px 6px; border: 1px solid var(--line); border-radius: 999px; background: var(--surface); }
.ring { width: 20px; height: 20px; border-radius: 50%; background: conic-gradient(var(--accent) calc(var(--p) * 1%), var(--line) 0); -webkit-mask: radial-gradient(circle, transparent 5.5px, #000 6px); mask: radial-gradient(circle, transparent 5.5px, #000 6px); }

/* ---------- Estructura ---------- */
.shell { display: grid; grid-template-columns: var(--side) minmax(0, 1fr); }
.sidebar {
  position: sticky; top: var(--top); height: calc(100vh - var(--top)); overflow-y: auto;
  border-right: 1px solid var(--line); padding: 18px 12px 60px; font-size: 14.5px; scrollbar-width: thin;
}
.sb-phase { margin-bottom: 18px; }
.sb-phase-title { font: 600 11px/1.3 var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--copper); margin: 0 8px 6px; }
.sb-mod summary { display: flex; align-items: center; gap: 8px; padding: 7px 8px; border-radius: 7px; cursor: pointer; list-style: none; }
.sb-mod summary::-webkit-details-marker { display: none; }
.sb-mod summary:hover { background: var(--surface-2); }
.sb-tag { font: 600 11px var(--mono); color: var(--muted); }
.sb-mod-title { flex: 1; font-weight: 600; line-height: 1.3; }
.sb-count { font: 11px var(--mono); color: var(--muted); }
.sb-count.full { color: var(--accent); font-weight: 700; }
.sb-mod ul { list-style: none; margin: 2px 0 8px 17px; padding: 0 0 0 10px; border-left: 2px solid var(--line); }
.sb-mod li a { display: flex; gap: 8px; align-items: baseline; padding: 5px 8px; border-radius: 6px; color: var(--muted); text-decoration: none; line-height: 1.35; }
.sb-mod li a:hover { color: var(--ink); background: var(--surface-2); }
.sb-mod li a[aria-current] { color: var(--ink); background: var(--accent-soft); font-weight: 600; }
.tick { flex: none; width: 11px; height: 11px; border-radius: 50%; border: 2px solid var(--line); translate: 0 1px; }
.done > .tick, a.done .tick, li.done .tick { background: var(--accent); border-color: var(--accent); }

main { min-width: 0; outline: none; }
.page { max-width: 800px; margin: 0 auto; padding: 34px 28px 90px; }
.page.lab { max-width: 860px; }
.crumbs { font-size: 14px; color: var(--muted); margin-bottom: 22px; }
.crumbs a { color: var(--muted); }
.crumbs span { opacity: .5; margin: 0 4px; }

/* ---------- Botones y barras ---------- */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 46px; padding: 0 20px; border-radius: 9px; border: 1.5px solid var(--line); background: var(--surface); color: var(--ink); font: 600 16px var(--body); text-decoration: none; cursor: pointer; }
.btn:hover { border-color: var(--ink); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn.primary:hover { filter: brightness(1.08); }
.btn.done { background: var(--accent-soft); border-color: var(--accent); color: var(--ink); }
.link { background: none; border: 0; padding: 0; color: var(--muted); font: inherit; text-decoration: underline; cursor: pointer; }
.bar { display: block; height: 5px; border-radius: 3px; background: var(--line); overflow: hidden; }
.bar i { display: block; height: 100%; background: var(--accent); border-radius: 3px; transition: width .4s; }
.bar.big { height: 8px; margin-top: 20px; }

/* ---------- Portada ---------- */
.home { max-width: 1160px; margin: 0 auto; padding: 0 30px 70px; }
.hero { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(280px, .75fr); gap: 50px; align-items: center; padding: 56px 0 46px; }
.hero h1 { font-size: clamp(34px, 4.6vw, 58px); font-weight: 700; letter-spacing: -.02em; line-height: 1.04; }
.hero .lead { font-size: 19px; color: var(--muted); max-width: 56ch; margin: 22px 0 26px; }
.cta { display: flex; flex-wrap: wrap; gap: 12px; }
.stats { display: flex; flex-wrap: wrap; gap: 8px 30px; margin: 34px 0 0; padding-top: 22px; border-top: 1px solid var(--line); }
.stats dt { font: 11px var(--mono); text-transform: uppercase; letter-spacing: .08em; color: var(--muted); }
.stats dd { margin: 0; font: 700 28px var(--display); }

.hero-art { background-color: var(--surface); background-image: radial-gradient(var(--line) 1.2px, transparent 1.3px); background-size: 16px 16px; border: 1px solid var(--line); border-radius: 16px; padding: 22px; box-shadow: var(--shadow); }
.ladder-title, .ladder-foot { font: 600 11px var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--muted); margin: 0 0 12px; text-align: center; }
.ladder-foot { margin: 12px 0 0; color: var(--copper); }
.ladder { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; justify-items: center; }
.ladder li { width: calc(58% + var(--i) * 7%); }
.ladder a { display: flex; align-items: center; gap: 10px; padding: 9px 12px; background: var(--bg); border: 1.5px solid var(--line); border-left: 5px solid var(--copper); border-radius: 7px; color: var(--ink); text-decoration: none; font: 600 15px var(--display); transition: translate .15s, border-color .15s; }
.ladder a span { font: 11px var(--mono); color: var(--muted); }
.ladder a:hover { translate: 4px 0; border-color: var(--accent); border-left-color: var(--accent); }
.ladder li:first-child a { border-left-color: var(--accent); }

.resume { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 18px 22px; margin-bottom: 34px; }
.resume p { margin: 12px 0 0; }
.home h2 { font-size: 30px; margin-bottom: 20px; }
.method { margin: 20px 0 58px; }
.method-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; border: 1px solid var(--line); border-radius: 12px; background: var(--surface); }
.method-grid > div { padding: 22px 24px; }
.method-grid > div + div { border-left: 1px solid var(--line); }
.method-grid h3 { font-size: 19px; margin-bottom: 8px; color: var(--accent); }
.method-grid p { margin: 0; color: var(--muted); font-size: 15.5px; line-height: 1.55; }

/* El recorrido: una pista de cobre que baja por la página, con una "vía" por fase */
.roadmap { position: relative; }
.phase { display: grid; grid-template-columns: 54px minmax(0, 1fr); gap: 20px; position: relative; padding-bottom: 38px; }
.phase::before { content: ""; position: absolute; left: 25px; top: 46px; bottom: -2px; width: 4px; background: var(--copper); opacity: .45; border-radius: 2px; }
.phase:last-child::before { display: none; }
.phase-pad { width: 54px; height: 54px; border-radius: 50%; display: grid; place-items: center; font: 700 20px var(--display); background: var(--bg); border: 4px solid var(--copper); color: var(--copper); box-shadow: 0 0 0 5px var(--bg); position: relative; z-index: 1; }
.phase.full .phase-pad { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.phase-body h3 { font-size: 23px; margin-top: 12px; }
.phase-desc { color: var(--muted); margin: 6px 0 16px; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 14px; }
.card { display: flex; flex-direction: column; background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 18px; color: var(--ink); text-decoration: none; transition: border-color .15s, translate .15s, box-shadow .15s; }
.card:hover { border-color: var(--accent); translate: 0 -2px; box-shadow: var(--shadow); }
.card-tag { font: 600 12px var(--mono); color: var(--copper); letter-spacing: .06em; }
.card h4 { font-size: 20px; margin: 6px 0 8px; }
.card p { color: var(--muted); font-size: 15px; line-height: 1.5; flex: 1; }
.card-foot { display: grid; gap: 8px; font: 12px var(--mono); color: var(--muted); }
.foot { display: flex; flex-wrap: wrap; gap: 8px 20px; justify-content: space-between; border-top: 1px solid var(--line); padding-top: 20px; margin-top: 30px; color: var(--muted); font-size: 14px; }
.foot p { margin: 0; }

/* ---------- Módulo ---------- */
.mod-head { margin-bottom: 30px; }
.mod-head h1, .lesson-head h1 { font-size: clamp(30px, 4vw, 44px); letter-spacing: -.015em; }
.lead { font-size: 19px; color: var(--muted); margin: 14px 0 0; }
.outcome { margin: 16px 0 0; padding: 12px 16px; background: var(--accent-soft); border-radius: 8px; }
.lesson-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.lesson-list a { display: flex; align-items: center; gap: 16px; padding: 14px 18px; background: var(--surface); border: 1px solid var(--line); border-radius: 10px; color: var(--ink); text-decoration: none; }
.lesson-list a:hover { border-color: var(--accent); }
.lesson-list .num { font: 700 18px var(--display); color: var(--copper); width: 26px; }
.lesson-list .lt { flex: 1; display: grid; }
.lesson-list small { color: var(--muted); font-size: 14px; line-height: 1.4; }
.lesson-list .lm { font: 12px var(--mono); color: var(--muted); white-space: nowrap; }
.filter { width: 100%; margin-top: 20px; height: 44px; padding: 0 14px; border: 1px solid var(--line); border-radius: 9px; background: var(--surface); color: var(--ink); font: inherit; }
.glossary { margin: 0; display: grid; gap: 0; }
.glossary > div { padding: 14px 0; border-bottom: 1px solid var(--line); display: grid; grid-template-columns: 210px 1fr; gap: 16px; }
.glossary dt { font: 700 17px var(--display); }
.glossary dd { margin: 0; color: var(--muted); }

/* ---------- Lección ---------- */
.lesson-head { margin-bottom: 26px; }
.goals { background: var(--surface); border: 1px solid var(--line); border-left: 5px solid var(--accent); border-radius: 10px; padding: 16px 20px; margin-bottom: 30px; }
.goals ul { margin: 0; padding-left: 20px; }
.goals li { margin: 3px 0; }

.prose > h2 { font-size: 27px; margin: 46px 0 14px; padding-top: 6px; }
.prose > h3 { font-size: 21px; margin: 32px 0 10px; }
.prose > p, .prose > ul, .prose > ol { max-width: 70ch; }
.prose ul, .prose ol { padding-left: 24px; margin: 0 0 1em; }
.prose li { margin: 5px 0; }
.prose strong, .prose b { font-weight: 650; }
.prose code { font: .88em var(--mono); background: var(--surface-2); border: 1px solid var(--line); padding: 1px 5px; border-radius: 4px; overflow-wrap: anywhere; }
.prose table { width: 100%; border-collapse: collapse; margin: 0 0 1.4em; font-size: 15.5px; display: block; overflow-x: auto; }
.prose th { text-align: left; font: 600 12px var(--mono); letter-spacing: .06em; text-transform: uppercase; color: var(--muted); border-bottom: 2px solid var(--line); padding: 8px 12px; white-space: nowrap; }
.prose td { padding: 9px 12px; border-bottom: 1px solid var(--line); vertical-align: top; }
.prose .big { font: 700 clamp(24px, 4vw, 34px) var(--display); text-align: center; margin: 24px 0; color: var(--accent); letter-spacing: .01em; }
.prose .big small { display: block; font: 400 15px var(--body); color: var(--muted); margin-top: 6px; }
.trio { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 0 0 1.4em; }
.trio > div { background: var(--surface); border: 1px solid var(--line); border-top: 4px solid var(--copper); border-radius: 10px; padding: 14px 16px; }
.trio h4 { font-size: 18px; margin-bottom: 4px; }
.trio .unit { font: 600 12px var(--mono); color: var(--copper); }
.trio p { margin: 6px 0 0; font-size: 15px; color: var(--muted); line-height: 1.5; }

.note, .think, .quiz, .ex, .widget, .mat, figure.code, figure.fig { margin: 26px 0; }
.note { border-radius: 10px; padding: 14px 18px; background: var(--info-soft); border-left: 5px solid var(--info); }
.note .label { color: var(--info); }
.note > div > :last-child { margin-bottom: 0; }
.note-tip, .note-key { background: var(--accent-soft); border-color: var(--accent); }
.note-tip .label, .note-key .label { color: var(--accent); }
.note-warn { background: var(--signal-soft); border-color: #e0a100; }
.note-warn .label { color: var(--signal-ink); }
.note-danger { background: var(--danger-soft); border-color: var(--danger); }
.note-danger .label { color: var(--danger); }
.note-ana, .note-real { background: var(--copper-soft); border-color: var(--copper); }
.note-ana .label, .note-real .label { color: var(--copper); }

.mat { border: 1.5px dashed var(--line); border-radius: 10px; padding: 14px 18px; }
.mat ul { margin: 0; padding-left: 20px; columns: 2; column-gap: 30px; }
.mat li { break-inside: avoid; margin: 2px 0; }
.steps { counter-reset: s; list-style: none; padding: 0 !important; }
.steps li { counter-increment: s; position: relative; padding: 4px 0 12px 46px; margin: 0; }
.steps li::before { content: counter(s); position: absolute; left: 0; top: 2px; width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center; background: var(--copper); color: #fff; font: 700 14px var(--display); }
.steps li:not(:last-child)::after { content: ""; position: absolute; left: 14px; top: 36px; bottom: 2px; width: 2px; background: var(--line); }

.think { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 18px 20px; position: relative; overflow: hidden; }
.think::before { content: "?"; position: absolute; right: 12px; top: -22px; font: 700 110px var(--display); color: var(--signal); opacity: .28; pointer-events: none; }
.think .label { color: var(--signal-ink); }
.think-q { font-size: 18.5px; font-weight: 600; line-height: 1.45; max-width: 60ch; }
.think-q > :last-child { margin-bottom: 0; }
details > summary { cursor: pointer; font-weight: 600; color: var(--accent); width: fit-content; padding: 4px 0; }
.think details { margin-top: 12px; }
.think-a { padding: 12px 0 0; border-top: 1px dashed var(--line); margin-top: 8px; }
.think-a > :last-child { margin-bottom: 0; }

.quiz { border: 1px solid var(--line); border-radius: 12px; background: var(--surface); padding: 18px 20px; }
.quiz header { display: flex; justify-content: space-between; align-items: baseline; }
.quiz-score { font: 600 13px var(--mono); color: var(--muted); }
.quiz.complete .quiz-score { color: var(--accent); }
.quiz ol { margin: 0; padding-left: 22px; }
.qi { margin: 14px 0 20px; }
.qq { font-weight: 600; margin-bottom: 10px; }
.opts { display: grid; gap: 8px; }
.opt { text-align: left; padding: 10px 14px; border: 1.5px solid var(--line); border-radius: 8px; background: var(--bg); color: var(--ink); font: inherit; font-size: 16px; cursor: pointer; line-height: 1.4; }
.opt:hover:not(:disabled) { border-color: var(--accent); }
.opt:disabled { cursor: default; opacity: .6; }
.opt.right { border-color: var(--accent); background: var(--accent-soft); opacity: 1; font-weight: 600; }
.opt.right::after { content: "  ✓ Correcto"; color: var(--accent); font: 600 13px var(--mono); }
.opt.wrong { border-color: var(--danger); background: var(--danger-soft); text-decoration: line-through; text-decoration-color: var(--danger); }
.why { margin: 10px 0 0; padding: 10px 14px; background: var(--surface-2); border-radius: 8px; font-size: 15.5px; }

.ex { border: 1.5px solid var(--copper); border-radius: 12px; padding: 18px 20px; background: var(--surface); }
.ex .label { color: var(--copper); }
.ex .lvl { letter-spacing: 2px; margin-left: 6px; }
.ex h4 { font-size: 21px; margin-bottom: 10px; }
.ex-body > :last-child { margin-bottom: 0; }
.ex details { margin-top: 10px; }
.ex details > div { padding: 10px 14px; background: var(--surface-2); border-radius: 8px; margin-top: 4px; }
.ex details > div > :last-child { margin-bottom: 0; }
.ex details figure.code { margin: 12px 0; }
.ex-done { display: flex; align-items: center; gap: 9px; margin-top: 16px; padding-top: 14px; border-top: 1px dashed var(--line); font-weight: 600; cursor: pointer; width: 100%; }
.ex-done input { width: 20px; height: 20px; accent-color: var(--accent); }
.ex.complete { border-color: var(--accent); }

figure.code { border-radius: 10px; overflow: hidden; background: var(--code-bg); border: 1px solid var(--line); }
figure.code figcaption { display: flex; justify-content: space-between; align-items: center; padding: 7px 8px 7px 16px; font: 12px var(--mono); letter-spacing: .05em; color: #8fa699; border-bottom: 1px solid rgba(255, 255, 255, .08); }
.copy { background: none; border: 1px solid rgba(255, 255, 255, .18); color: #c8d6ce; border-radius: 6px; padding: 4px 10px; font: 12px var(--mono); cursor: pointer; }
.copy:hover { background: rgba(255, 255, 255, .1); }
figure.code pre { margin: 0; padding: 16px; overflow-x: auto; font: 14.5px/1.6 var(--mono); color: var(--code-ink); tab-size: 2; }
figure.code code { font: inherit; background: none; border: 0; padding: 0; }
.tk-c { color: #7d9488; font-style: italic; }
.tk-s { color: #f0b072; }
.tk-n { color: #ffd166; }
.tk-k { color: #5fe0a5; }
.tk-f { color: #8ecbf5; }

figure.fig { background-color: var(--surface); background-image: radial-gradient(var(--line) 1px, transparent 1.2px); background-size: 14px 14px; border: 1px solid var(--line); border-radius: 12px; padding: 18px; text-align: center; }
figure.fig figcaption { font-size: 14.5px; color: var(--muted); margin-top: 12px; line-height: 1.5; background: var(--surface); display: inline-block; padding: 2px 8px; border-radius: 4px; }
.dg { width: 100%; max-width: 560px; height: auto; }
.dg .w { fill: none; stroke: var(--ink); stroke-width: 2.2; stroke-linecap: round; stroke-linejoin: round; }
.dg .thin { stroke-width: 1.4; }
.dg .n { fill: var(--ink); }
.dg .t { font: 600 13px var(--mono); fill: var(--ink); }
.dg .t.s { font-weight: 500; fill: var(--muted); font-size: 12px; }
.dg .t.c { fill: var(--copper); }
.dg .t.g { fill: var(--accent); }
.dg .b { fill: var(--accent-soft); stroke: var(--accent); stroke-width: 2; }
.dg .b.alt { fill: var(--copper-soft); stroke: var(--copper); }
.dg .b.plain { fill: var(--surface-2); stroke: var(--muted); }
.dg .led { fill: var(--signal); stroke: var(--ink); stroke-width: 2; stroke-linejoin: round; }
.dg .cu { stroke: var(--copper); }
.dg .gr { stroke: var(--accent); }
.dg .rd { stroke: var(--danger); }
.dg .bl { stroke: var(--info); }
.dg .ah { fill: var(--copper); }
.dg .hole { fill: var(--muted); opacity: .55; }
.dg .board { fill: var(--surface-2); stroke: var(--line); stroke-width: 1.5; }
.dg .soft { fill: var(--surface-2); stroke: var(--muted); stroke-width: 1.5; }

/* ---------- Widgets ---------- */
.widget { background: var(--surface); border: 1px solid var(--line); border-top: 4px solid var(--accent); border-radius: 12px; padding: 18px 20px 20px; box-shadow: var(--shadow); }
.widget .label { color: var(--accent); }
.widget h4 { font-size: 21px; }
.w-desc { color: var(--muted); font-size: 15px; margin: 6px 0 0; }
.w-body { margin-top: 16px; }
.w-row { display: flex; flex-wrap: wrap; gap: 14px 22px; align-items: flex-end; }
.w-field { display: grid; gap: 4px; flex: 1 1 150px; min-width: 0; }
.w-field > span { font: 600 12px var(--mono); letter-spacing: .05em; text-transform: uppercase; color: var(--muted); }
.w-field output { font: 600 14px var(--mono); color: var(--ink); text-transform: none; letter-spacing: 0; }
.w-body input[type="number"], .w-body select, .w-body textarea, .w-body input[type="text"] { width: 100%; height: 42px; padding: 0 10px; border: 1.5px solid var(--line); border-radius: 8px; background: var(--bg); color: var(--ink); font: 16px var(--mono); }
.w-body textarea { height: 110px; padding: 10px; font: 14px/1.5 var(--body); resize: vertical; }
.w-body input[type="range"] { width: 100%; accent-color: var(--accent); height: 28px; }
.w-out { margin-top: 16px; padding: 14px 16px; background: var(--bg); border: 1px solid var(--line); border-radius: 10px; }
.w-big { font: 700 30px var(--display); color: var(--accent); line-height: 1.2; }
.w-formula { font: 14px var(--mono); color: var(--muted); margin-top: 4px; overflow-wrap: anywhere; }
.w-warn { color: var(--danger); font-weight: 600; font-size: 15px; margin-top: 8px; }
.w-ok { color: var(--accent); font-weight: 600; font-size: 15px; margin-top: 8px; }
.w-tabs { display: inline-flex; border: 1.5px solid var(--line); border-radius: 9px; overflow: hidden; margin-bottom: 14px; }
.w-tabs button, .w-btn { border: 0; background: var(--bg); color: var(--ink); font: 600 14px var(--body); padding: 9px 14px; cursor: pointer; }
.w-tabs button + button { border-left: 1.5px solid var(--line); }
.w-tabs button[aria-pressed="true"] { background: var(--accent); color: var(--accent-ink); }
.w-btn { border: 1.5px solid var(--line); border-radius: 8px; height: 42px; }
.w-btn:hover { border-color: var(--accent); }
.w-btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.w-meter { height: 14px; border-radius: 7px; background: var(--line); overflow: hidden; margin-top: 10px; }
.w-meter i { display: block; height: 100%; background: linear-gradient(90deg, var(--accent), var(--signal)); border-radius: 7px; }
.w-split { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.w-svg { width: 100%; height: auto; display: block; }
.w-svg .axis { stroke: var(--line); stroke-width: 1.5; fill: none; }
.w-svg .sig { stroke: var(--accent); stroke-width: 2.5; fill: none; stroke-linejoin: round; }
.w-svg .avg { stroke: var(--copper); stroke-width: 2; stroke-dasharray: 6 5; fill: none; }
.w-svg text { font: 11px var(--mono); fill: var(--muted); }
.bits { display: flex; flex-wrap: wrap; gap: 6px; }
.bit { display: grid; gap: 2px; justify-items: center; }
.bit button { width: 46px; height: 54px; border-radius: 8px; border: 2px solid var(--line); background: var(--bg); color: var(--muted); font: 700 24px var(--mono); cursor: pointer; }
.bit button[aria-pressed="true"] { background: var(--signal); border-color: #e0a100; color: #2b2000; }
.bit small { font: 11px var(--mono); color: var(--muted); }
.lamp { width: 54px; height: 54px; border-radius: 50%; border: 3px solid var(--line); background: var(--surface-2); transition: background .15s, box-shadow .15s; flex: none; }
.lamp.on { background: var(--signal); border-color: #e0a100; box-shadow: 0 0 26px 4px rgba(255, 209, 102, .7); }
.toggle { min-width: 84px; height: 46px; border-radius: 8px; border: 2px solid var(--line); background: var(--bg); color: var(--ink); font: 700 16px var(--mono); cursor: pointer; }
.toggle[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.truth { border-collapse: collapse; font: 14px var(--mono); margin-top: 6px; }
.truth th, .truth td { padding: 5px 14px; border: 1px solid var(--line); text-align: center; }
.truth th { color: var(--muted); font-weight: 600; }
.truth tr.cur td { background: var(--signal-soft); font-weight: 700; }
.truth td.bad { color: var(--danger); }
.truth td.good { color: var(--accent); }
.res-svg rect.body { fill: #e3cfa5; stroke: #8f7a4c; stroke-width: 1.5; }
.probs { display: grid; gap: 4px; margin-top: 10px; font: 13px var(--mono); }
.probs div { display: grid; grid-template-columns: 110px 1fr 44px; gap: 8px; align-items: center; }
.probs i { display: block; height: 10px; background: var(--accent); border-radius: 5px; }
.gen { font-size: 17px; line-height: 1.6; min-height: 54px; }
.gen b { background: var(--signal-soft); border-radius: 3px; padding: 0 2px; }

/* ---------- Montajes guiados ---------- */
.guide { margin: 28px 0; background: var(--surface); border: 1px solid var(--line); border-top: 4px solid var(--copper); border-radius: 12px; padding: 18px 20px 20px; box-shadow: var(--shadow); }
.guide:focus-visible { outline-offset: 4px; }
.guide > header { display: flex; flex-wrap: wrap; gap: 10px 20px; justify-content: space-between; align-items: flex-end; }
.guide .label { color: var(--copper); }
.guide h4 { font-size: 21px; }
.guide .w-tabs { margin: 0; }
.guide .w-tabs button[aria-pressed="true"] { background: var(--copper); color: #fff; }
.g-intro { color: var(--muted); font-size: 15.5px; margin: 10px 0 0; }
/* El dibujo es una ilustración con colores propios: su fondo es claro también en el tema oscuro */
.g-stage, .g-thumb { background: #ece8dc; }
.g-stage { margin-top: 14px; border: 1px solid var(--line); border-radius: 10px; overflow-x: auto; }
.g-svg { display: block; width: 100%; min-width: 520px; max-width: 760px; height: auto; margin: 0 auto; }
.g-t { font: 600 9px var(--mono); fill: #3d4349; }
.g-pin { font-size: 6.6px; fill: #eaf7f8; font-weight: 500; }
.g-tiny { font-size: 7.5px; }
.g-num { font-size: 8px; fill: #8b8676; font-weight: 500; }
.g-lbl { font-size: 10px; fill: #20262a; paint-order: stroke; stroke: #f1ede3; stroke-width: 3px; stroke-linejoin: round; }
.g-white { fill: #fff; stroke: none; }
.g-dark { fill: #2b2f33; }
.g-brand { font: 700 15px var(--display); fill: #e7fbfc; letter-spacing: .06em; }
.g-lcd { font: 700 13px var(--mono); fill: #eaf1ff; }
.g-plus { font-size: 11px; fill: #d7263d; }
.g-minus { font-size: 11px; fill: #2b62c9; }
.g-lead { stroke: #9aa1a8; stroke-width: 2.4; stroke-linecap: round; }
.g-w { fill: none; stroke-width: 4.2; stroke-linecap: round; stroke-linejoin: round; }
.g-wo { stroke: rgba(0, 0, 0, .28); stroke-width: 6.4; }
.g-tip { fill: #c8ccd1; stroke: #6c737a; stroke-width: 1; }
.g-item:not(.g-on) { display: none; }
.guide[data-mode="steps"]:not(.g-final) .g-item.g-on:not(.g-new) { opacity: .62; }
.g-pulse { display: none; fill: none; stroke: #ff9f1c; stroke-width: 3; transform-box: fill-box; transform-origin: center; }
.g-new .g-pulse { display: block; animation: g-pulse 1.4s ease-out infinite; }
/* El trazado animado solo se aplica si el usuario no ha pedido reducir el movimiento: así el cable nunca queda oculto */
@media (prefers-reduced-motion: no-preference) {
  .g-new .g-w { stroke-dasharray: var(--len); stroke-dashoffset: var(--len); animation: g-draw .95s ease-out forwards; }
}
.g-new:not(.g-wire) > :not(.g-pulse) { animation: g-drop .5s cubic-bezier(.2, .8, .3, 1.2) both; }
@keyframes g-draw { to { stroke-dashoffset: 0; } }
@keyframes g-drop { from { opacity: 0; transform: translateY(-16px); } to { opacity: 1; transform: none; } }
@keyframes g-pulse { 0% { transform: scale(.35); opacity: 1; } 100% { transform: scale(1.5); opacity: 0; } }
.g-panel { margin-top: 14px; }
.g-head { display: flex; justify-content: space-between; align-items: center; }
.g-count { font: 600 12px var(--mono); letter-spacing: .09em; text-transform: uppercase; color: var(--copper); }
.g-play { border: 1.5px solid var(--line); background: var(--bg); color: var(--ink); border-radius: 999px; padding: 5px 14px; font: 600 13px var(--body); cursor: pointer; }
.g-play:hover { border-color: var(--copper); }
.g-text { font-size: 18px; line-height: 1.5; min-height: 4.5em; margin: 10px 0 14px; max-width: 62ch; }
.g-text b { background: var(--signal-soft); padding: 0 3px; border-radius: 3px; font-weight: 650; }
.g-nav { display: flex; align-items: center; gap: 12px; }
.g-nav .btn { min-height: 44px; padding: 0 16px; font-size: 15px; }
.g-nav .btn:disabled { opacity: .4; cursor: default; }
.g-dots { flex: 1; display: flex; flex-wrap: wrap; gap: 6px; justify-content: center; }
.g-dots button { width: 12px; height: 12px; padding: 0; border-radius: 50%; border: 2px solid var(--line); background: none; cursor: pointer; }
.g-dots button.past { background: var(--copper); border-color: var(--copper); opacity: .5; }
.g-dots button.on { background: var(--copper); border-color: var(--copper); scale: 1.3; }
.g-list { margin-top: 14px; font-size: 15.5px; }
.g-list ol { margin: 8px 0 0; padding-left: 22px; }
.g-list li { margin: 4px 0; }
.page.wide { max-width: 1160px; }
.g-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 16px; }
.g-card { display: flex; flex-direction: column; background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 12px 14px 14px; color: var(--ink); text-decoration: none; transition: border-color .15s, translate .15s, box-shadow .15s; }
.g-card:hover { border-color: var(--copper); translate: 0 -2px; box-shadow: var(--shadow); }
.g-thumb { border-radius: 8px; margin-bottom: 10px; overflow: hidden; }
.g-thumb .g-svg { min-width: 0; }
.g-card h4 { font-size: 18px; margin: 4px 0; }
.g-card p { margin: 0; font: 12px var(--mono); color: var(--muted); }

/* ---------- Saber por dónde vas ---------- */
.read-bar { position: absolute; left: 0; right: 0; bottom: -1px; height: 3px; pointer-events: none; }
.read-bar i { display: block; height: 100%; width: 0; background: var(--copper); border-radius: 0 2px 2px 0; }
.resume-btn { display: inline-flex; align-items: center; gap: 6px; height: 38px; padding: 0 14px; border-radius: 8px; background: var(--accent); color: var(--accent-ink); font: 600 14px var(--body); text-decoration: none; white-space: nowrap; }
.resume-btn:hover { filter: brightness(1.08); }
.here { font: 600 10.5px/1.2 var(--mono); font-style: normal; letter-spacing: .05em; text-transform: uppercase; color: #fff; background: var(--copper); padding: 2px 6px; border-radius: 4px; white-space: nowrap; vertical-align: 2px; }
:root[data-theme="dark"] .here { color: #1b1206; }
.sb-mod li a .here { display: block; width: fit-content; margin-top: 3px; }
.sb-mod li a.last { color: var(--ink); }
.started > .tick, a.started .tick, li.started .tick { border-color: var(--copper); background: linear-gradient(90deg, var(--copper) 50%, transparent 50%); }
.card-here { border-color: var(--copper); box-shadow: 0 0 0 1px var(--copper); }
.lesson-list li.last a { border-color: var(--copper); box-shadow: 0 0 0 1px var(--copper); }
.resume { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 14px 24px; align-items: center; border-left: 5px solid var(--copper); }
.resume .label { color: var(--copper); }
.resume h3 { font-size: 23px; }
.resume-meta { color: var(--muted); margin: 4px 0 0 !important; font-size: 15px; }
.resume-total { grid-column: 1 / -1; }
.resume-total p { margin: 8px 0 0; font-size: 14.5px; color: var(--muted); }
.resume-pill { position: fixed; left: 50%; bottom: 22px; translate: -50% 0; z-index: 15; border: 0; border-radius: 999px; padding: 12px 20px; background: var(--copper); color: #fff; font: 600 15px var(--body); cursor: pointer; box-shadow: var(--shadow); animation: pill-in .35s ease-out; }
:root[data-theme="dark"] .resume-pill { color: #1b1206; }
@keyframes pill-in { from { opacity: 0; translate: -50% 14px; } to { opacity: 1; translate: -50% 0; } }
.sync { flex-basis: 100%; }
.sync summary { color: var(--muted); font-weight: 400; text-decoration: underline; }
.sync-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 12px; }
.sync textarea { width: 100%; height: 76px; padding: 8px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); color: var(--ink); font: 12px var(--mono); resize: vertical; margin-bottom: 8px; word-break: break-all; }
.sync .btn { min-height: 40px; font-size: 15px; }
.sync p { margin: 0 0 6px; color: var(--ink); }
#syncMsg { margin-top: 10px; color: var(--accent); font-weight: 600; }

/* ---------- Final de lección ---------- */
.finish { margin: 46px 0 22px; padding-top: 26px; border-top: 1px solid var(--line); text-align: center; }
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.pager a { display: grid; gap: 2px; padding: 14px 18px; border: 1px solid var(--line); border-radius: 10px; background: var(--surface); color: var(--ink); text-decoration: none; font-weight: 600; line-height: 1.35; }
.pager a:hover { border-color: var(--accent); }
.pager small { font: 11px var(--mono); text-transform: uppercase; letter-spacing: .08em; color: var(--muted); font-weight: 400; }
.pager .next { text-align: right; }

/* ---------- Adaptación a pantallas pequeñas ---------- */
@media (max-width: 1020px) {
  .shell { grid-template-columns: minmax(0, 1fr); }
  .menu-btn { display: grid; }
  .sidebar { position: fixed; left: 0; top: var(--top); z-index: 25; width: min(330px, 88vw); background: var(--bg); translate: -105% 0; transition: translate .22s; box-shadow: var(--shadow); }
  .menu-open .sidebar { translate: 0 0; }
  .scrim { position: fixed; inset: var(--top) 0 0 0; background: rgba(0, 0, 0, .45); z-index: 20; }
  .hero { grid-template-columns: 1fr; gap: 34px; padding-top: 36px; }
}
@media (max-width: 760px) {
  body { font-size: 16.5px; }
  .topbar { padding: 0 10px; gap: 8px; }
  .topnav, .search kbd, .brand-name { display: none; }
  .search { width: auto; flex: 1; }
  .home { padding: 0 16px 60px; }
  .page { padding: 24px 16px 70px; }
  .method-grid, .trio, .w-split { grid-template-columns: 1fr; }
  .method-grid > div + div { border-left: 0; border-top: 1px solid var(--line); }
  .phase { grid-template-columns: 40px minmax(0, 1fr); gap: 12px; }
  .phase-pad { width: 40px; height: 40px; font-size: 16px; border-width: 3px; }
  .phase::before { left: 18px; top: 36px; }
  .phase-body h3 { margin-top: 6px; }
  .glossary > div { grid-template-columns: 1fr; gap: 2px; }
  .mat ul { columns: 1; }
  .pager { grid-template-columns: 1fr; }
  .pager .next { text-align: left; }
  .ladder li { width: 100%; }
  .resume-btn span { display: none; }
  .resume-btn { padding: 0 11px; }
  .resume, .sync-grid { grid-template-columns: 1fr; }
  .guide { padding: 14px 12px 16px; }
  .g-text { font-size: 17px; }
  .g-nav .btn { padding: 0 12px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; }
}
@media print {
  .topbar, .sidebar, .finish, .pager, .copy { display: none !important; }
  .shell { display: block; }
  details > div { display: block !important; }
}