:root {
  --ink: #1d2740;
  --muted: #7c8497;
  --pale: #aeb5c4;
  --canvas: #f7f8fb;
  --surface: #ffffff;
  --line: #e6e9f0;
  --blue: #5368d8;
  --blue-dark: #4054c2;
  --blue-soft: #eef1ff;
  --orange: #e79a4d;
  --orange-soft: #fff3e3;
  --green: #41a477;
  --green-soft: #eaf8f0;
  --red: #d9777c;
  --sidebar-width: 76px;
  --radius: 18px;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--canvas);
  font-synthesis: none;
}

* { box-sizing: border-box; }
html { min-width: 300px; scroll-behavior: smooth; }
body { margin: 0; min-width: 300px; background: var(--canvas); color: var(--ink); }
button, input { font: inherit; }
button { cursor: pointer; }
button:focus-visible, input:focus-visible { outline: 3px solid rgba(83,104,216,.28); outline-offset: 3px; }
button:disabled { cursor: not-allowed; opacity: .45; }
[hidden] { display: none !important; }

.app-shell { min-height: 100vh; }
.sidebar { position: fixed; z-index: 20; inset: 0 auto 0 0; width: var(--sidebar-width); background: var(--surface); border-right: 1px solid var(--line); display: flex; flex-direction: column; align-items: center; padding: 20px 11px 17px; }
.brand-wrap { width: 100%; display: flex; justify-content: center; align-items: center; margin-bottom: 45px; }
.brand { display: inline-flex; border: 0; background: transparent; padding: 0; align-items: center; gap: 10px; color: var(--ink); font-weight: 800; }
.brand-mark { width: 34px; height: 34px; display: grid; place-items: center; color: #fff; background: var(--blue); border-radius: 11px 11px 11px 4px; font-weight: 900; font-size: 16px; }
.brand-name { display: none; font-size: 14px; letter-spacing: -.4px; }
.icon-button { width: 36px; height: 36px; display: inline-grid; place-items: center; border: 0; border-radius: 10px; background: transparent; color: var(--muted); font-size: 19px; }
.icon-button:hover { color: var(--ink); background: var(--canvas); }
.sidebar-close { display: none; }
.main-nav { display: grid; gap: 10px; width: 100%; }
.nav-item { width: 100%; min-height: 45px; display: flex; align-items: center; justify-content: center; gap: 10px; border: 0; border-radius: 13px; background: transparent; color: var(--muted); font-size: 11px; font-weight: 700; transition: color .18s, background .18s; }
.nav-item:hover { color: var(--ink); background: #f8f9fc; }
.nav-item.active { color: var(--blue); background: var(--blue-soft); }
.nav-icon { width: 22px; height: 22px; display: grid; place-items: center; color: currentColor; font-size: 15px; font-weight: 900; }
.nav-item > span:not(.nav-icon) { display: none; }
.sidebar-footer { margin-top: auto; display: grid; gap: 12px; justify-items: center; }
.reset-link { display: none; border: 0; background: transparent; color: var(--pale); font-size: 9px; padding: 0; }
.reset-link:hover { color: var(--red); }
.version-label { color: #c8ccd5; font-size: 8px; }
.mobile-overlay { display: none; }

.main-content { min-height: 100vh; margin-left: var(--sidebar-width); display: flex; flex-direction: column; }
.topbar { min-height: 66px; display: flex; align-items: center; justify-content: space-between; gap: 18px; padding: 0 36px; border-bottom: 1px solid var(--line); background: rgba(247,248,251,.93); position: sticky; top: 0; z-index: 10; backdrop-filter: blur(16px); }
.menu-button { display: none; }
.breadcrumb { display: flex; align-items: center; gap: 8px; color: var(--pale); font-size: 10px; }
.breadcrumb strong { color: var(--ink); font-weight: 800; }
.breadcrumb-separator { color: #d0d4dc; }
.topbar-actions { display: flex; align-items: center; gap: 13px; }
.today-label { color: var(--pale); font-size: 9px; text-transform: capitalize; }
.focus-button { border: 1px solid #e0e5fc; border-radius: 9px; padding: 7px 10px; display: inline-flex; align-items: center; gap: 6px; color: var(--blue); background: var(--blue-soft); font-size: 9px; font-weight: 800; }
.focus-button:hover, .focus-button[aria-pressed="true"] { color: #fff; background: var(--blue); }
.screen-container { width: min(1050px, 100%); margin: 0 auto; padding: 46px 48px 20px; flex: 1; }
.screen { display: none; animation: appear .22s ease both; }
.screen.active { display: block; }
@keyframes appear { from { opacity: 0; transform: translateY(5px); } to { opacity: 1; transform: translateY(0); } }
.app-footer { width: min(1050px,100%); margin: 0 auto; display: flex; justify-content: space-between; gap: 14px; padding: 7px 48px 18px; color: #b8beca; font-size: 9px; }
.eyebrow { display: inline-block; color: var(--blue); font-size: 9px; line-height: 1.4; letter-spacing: 1.05px; font-weight: 900; }
.simple-panel { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); }

/* Inicio */
.minimal-hero { min-height: 284px; display: flex; align-items: center; justify-content: space-between; gap: 30px; padding: 44px 47px; border-radius: 23px; background: linear-gradient(112deg, #eef1ff, #f8f8ff 65%, #fff9ed); border: 1px solid #e4e8fc; }
.minimal-hero h1 { margin: 8px 0 12px; color: var(--ink); font-size: clamp(31px,4.5vw,49px); line-height: 1.02; letter-spacing: -2px; }
.minimal-hero p { max-width: 480px; margin: 0 0 23px; color: var(--muted); font-size: 13px; line-height: 1.65; }
.home-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.primary-button, .quiet-button, .text-button, .hint-button { border-radius: 10px; font-size: 10px; font-weight: 800; transition: transform .16s, background .16s, box-shadow .16s; }
.primary-button { border: 0; padding: 12px 16px; color: #fff; background: var(--blue); box-shadow: 0 8px 18px rgba(83,104,216,.2); }
.primary-button:hover { background: var(--blue-dark); transform: translateY(-1px); box-shadow: 0 11px 22px rgba(83,104,216,.28); }
.primary-button span { margin-left: 7px; font-size: 14px; }
.quiet-button { border: 1px solid var(--line); padding: 10px 13px; color: var(--ink); background: #fff; }
.quiet-button:hover { border-color: #ccd4f7; color: var(--blue); background: #fafbff; }
.hero-example { position: relative; min-width: 246px; min-height: 170px; display: flex; align-items: center; justify-content: center; gap: 13px; color: var(--blue); }
.hero-example::before { content: ""; position: absolute; width: 170px; height: 170px; border: 1px dashed #cbd4fb; border-radius: 50%; }
.hero-example span, .hero-example strong { position: relative; z-index: 1; display: grid; place-items: center; width: 76px; height: 66px; border-radius: 16px; font-size: 25px; font-weight: 900; }
.hero-example span { color: #fff; background: var(--blue); transform: rotate(-5deg); }.hero-example strong { background: #fff; color: var(--blue); transform: rotate(5deg); box-shadow: 0 8px 20px rgba(54,65,130,.09); }.hero-example b { position: relative; z-index: 1; color: var(--orange); font-size: 27px; }.hero-example small { position: absolute; right: 0; bottom: 2px; color: #af7a37; font-size: 9px; line-height: 1.4; text-align: center; }
.four-steps { display: flex; align-items: center; justify-content: center; gap: 18px; margin: 27px 0; color: var(--muted); }.four-steps div { display: flex; align-items: center; gap: 7px; }.four-steps b { width: 23px; height: 23px; display: grid; place-items: center; border-radius: 50%; color: var(--blue); background: var(--blue-soft); font-size: 10px; }.four-steps span { font-size: 10px; font-weight: 700; }.four-steps i { color: #cbd0db; font-style: normal; font-size: 14px; }
.home-bottom { display: grid; grid-template-columns: 1.25fr .75fr; gap: 15px; }.example-panel, .progress-mini { min-height: 164px; padding: 22px; }.panel-title { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; }.panel-title h2 { margin: 6px 0 0; font-size: 16px; letter-spacing: -.4px; }.example-panel p { max-width: 520px; margin: 17px 0 0; color: var(--muted); font-size: 10px; line-height: 1.6; }.rule-inline { display: flex; align-items: center; gap: 19px; margin-top: 22px; }.rule-inline span:not(.rule-divider) { display: flex; align-items: center; gap: 9px; font-size: 16px; font-weight: 900; }.rule-inline small { font-size: 9px; font-weight: 700; }.down-rule { color: var(--blue); }.up-rule { color: var(--orange); }.rule-divider { width: 1px; height: 27px; background: var(--line); }.text-button { border: 0; padding: 0; color: var(--blue); background: transparent; }.text-button:hover { text-decoration: underline; }.mini-progress-value { display: flex; align-items: baseline; gap: 7px; margin: 19px 0 10px; }.mini-progress-value strong { color: var(--blue); font-size: 28px; letter-spacing: -1px; }.mini-progress-value span { color: var(--muted); font-size: 9px; }.progress-track, .question-progress, .mini-track, .mastery-track { overflow: hidden; border-radius: 99px; background: #eef0f5; }.progress-track { height: 6px; }.progress-track span, .question-progress span, .mastery-track span { display: block; height: 100%; border-radius: inherit; background: var(--blue); transition: width .35s; }.mini-progress-foot { display: flex; justify-content: space-between; gap: 8px; margin-top: 10px; color: var(--pale); font-size: 8px; }.hidden-metrics { display: none; }

/* Aprendizaje */
.page-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 18px; margin-bottom: 24px; }.page-heading h1 { margin: 6px 0 6px; font-size: clamp(27px,3.5vw,37px); letter-spacing: -1.4px; }.page-heading p { margin: 0; color: var(--muted); font-size: 11px; line-height: 1.55; }.target-tabs { display: grid; grid-template-columns: repeat(3,1fr); gap: 9px; margin-bottom: 15px; }.target-tab { border: 1px solid var(--line); border-radius: 13px; padding: 12px 14px; display: flex; align-items: baseline; justify-content: space-between; gap: 10px; color: var(--muted); background: #fff; text-align: left; }.target-tab:hover { border-color: #ccd4f7; }.target-tab.active { color: var(--blue); border-color: #cad3ff; background: var(--blue-soft); }.target-tab strong { font-size: 11px; }.target-tab small { color: var(--pale); font-size: 9px; }.lesson-layout { display: grid; grid-template-columns: minmax(0,1.5fr) minmax(245px,.7fr); gap: 15px; align-items: start; }.lesson-card { min-height: 476px; padding: 20px 24px 17px; }.lesson-progress-head { display: flex; align-items: center; justify-content: space-between; color: var(--pale); font-size: 9px; }.step-dots { display: flex; gap: 6px; }.step-dot { width: 8px; height: 8px; border-radius: 50%; background: #e2e5ec; }.step-dot.active { background: var(--blue); transform: scale(1.18); }.step-dot.done { background: #b9c3f7; }.lesson-visual { min-height: 244px; display: grid; place-items: center; padding: 24px 5px 15px; }.lesson-copy { min-height: 86px; text-align: center; }.lesson-copy .lesson-kicker { color: var(--orange); font-size: 8px; letter-spacing: 1px; font-weight: 900; }.lesson-copy h2 { margin: 7px 0 7px; font-size: 21px; letter-spacing: -.7px; }.lesson-copy p { max-width: 560px; margin: 0 auto; color: var(--muted); font-size: 11px; line-height: 1.6; }.lesson-copy strong { color: var(--blue); }.lesson-navigation { display: flex; justify-content: space-between; gap: 10px; padding-top: 14px; border-top: 1px solid #f0f1f5; }.rule-aside { display: grid; gap: 10px; }.rule-card, .check-card, .micro-example { padding: 18px; }.rule-split { display: grid; grid-template-columns: 1fr 1px 1fr; align-items: center; gap: 8px; margin: 18px 0 14px; text-align: center; }.rule-split strong { display: block; font-size: 9px; white-space: nowrap; }.rule-split small { display: block; color: var(--muted); font-size: 8px; }.rule-split .rule-divider { height: 45px; }.rule-arrow { display: block; font-size: 27px; line-height: 1; font-weight: 900; }.rule-arrow.down { color: var(--blue); }.rule-arrow.up { color: var(--orange); }.rule-card p { margin: 0; color: var(--muted); font-size: 9px; line-height: 1.55; }.check-card { background: var(--green-soft); border-color: #d9f0e3; }.check-card strong { display: block; color: #2f8562; font-size: 10px; }.check-card p { margin: 5px 0 0; color: #5c8c78; font-size: 9px; line-height: 1.5; }.check-card p span { color: #2f8562; font-weight: 900; }.micro-example { background: var(--orange-soft); border-color: #f7e7d0; }.micro-example span { color: #b5782d; font-size: 8px; letter-spacing: .8px; font-weight: 900; text-transform: uppercase; }.micro-example strong { display: block; color: #8e5c20; margin: 7px 0 3px; font-size: 21px; }.micro-example small { color: #b3834d; font-size: 8px; }
.lesson-number-board { position: relative; display: flex; align-items: center; gap: 4px; padding: 22px 27px 19px; border: 1px solid #edf0f6; border-radius: 19px; background: #fcfcfe; box-shadow: 0 8px 20px rgba(39,48,91,.05); }.lesson-number-board .digit { position: relative; color: var(--ink); font-size: clamp(53px,8vw,82px); font-weight: 900; letter-spacing: -5px; line-height: 1; }.lesson-number-board .digit.highlight { color: var(--blue); }.lesson-number-board .digit.highlight::after { content: ""; position: absolute; left: 3px; right: 2px; bottom: -5px; height: 4px; border-radius: 5px; background: var(--orange); }.board-label { position: absolute; top: -11px; left: 17px; padding: 4px 7px; border: 1px solid #e2e6f8; border-radius: 7px; color: var(--blue); background: #fff; font-size: 8px; font-weight: 900; }.digit-caption { position: absolute; bottom: -34px; left: 50%; transform: translateX(-50%); color: var(--orange); font-size: 9px; white-space: nowrap; letter-spacing: 0; }.lesson-eye { position: absolute; top: -34px; left: 50%; transform: translateX(-50%); color: var(--muted); font-size: 20px; letter-spacing: 4px; }.rule-visual-board { width: min(540px,100%); display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 15px; }.rule-visual-col { padding: 16px 11px 12px; border: 1px solid #edf0f6; border-radius: 15px; background: #fcfcfe; text-align: center; }.rule-visual-col.active-down { border-color: #ccdbff; background: #f2f6ff; }.rule-visual-col.active-up { border-color: #f8dfbe; background: #fff8ee; }.rule-visual-col .digit-set { color: var(--ink); font-size: 16px; font-weight: 900; letter-spacing: 1px; white-space: nowrap; }.rule-visual-col .visual-arrow { display: block; font-size: 31px; font-weight: 900; line-height: 1.15; }.active-down .visual-arrow { color: var(--blue); }.active-up .visual-arrow { color: var(--orange); }.rule-visual-col small { color: var(--muted); font-size: 8px; }.rule-visual-middle { color: var(--muted); font-size: 25px; text-align: center; }.result-visual { display: flex; flex-direction: column; align-items: center; gap: 11px; }.result-equation { display: flex; align-items: center; gap: 12px; font-size: clamp(32px,6vw,58px); font-weight: 900; letter-spacing: -3px; }.result-equation .old-number { color: var(--muted); }.result-equation .equation-arrow { color: var(--orange); font-size: 30px; }.result-equation .new-number { color: var(--blue); }.final-step-visual { padding: 15px 24px; border: 1px solid #e4e8ff; border-radius: 16px; background: #f7f8ff; text-align: center; }.final-step-visual .final-check { color: var(--green); font-size: 23px; }.final-step-visual strong { display: block; color: var(--blue); font-size: 33px; letter-spacing: -2px; }.final-step-visual small { color: var(--muted); font-size: 8px; }.line-visual { width: min(570px,100%); position: relative; padding: 23px 18px 7px; }.line-visual .line { height: 3px; position: relative; border-radius: 4px; background: var(--ink); }.line-visual .line::after { content: ""; position: absolute; right: -4px; top: -6px; border-left: 12px solid var(--ink); border-top: 8px solid transparent; border-bottom: 8px solid transparent; }.line-ticks { position: absolute; top: 15px; left: 18px; right: 18px; display: flex; justify-content: space-between; }.line-tick { position: relative; width: 2px; height: 18px; border-radius: 3px; background: var(--ink); }.line-tick span { position: absolute; top: 25px; left: 50%; transform: translateX(-50%); color: var(--muted); font-size: 8px; white-space: nowrap; }.line-point { position: absolute; top: 8px; width: 13px; height: 13px; border: 3px solid #fff; border-radius: 50%; background: var(--orange); box-shadow: 0 0 0 2px var(--orange); transform: translateX(-50%); }.line-point small { position: absolute; top: -29px; left: 50%; transform: translateX(-50%); color: var(--orange); font-size: 9px; font-weight: 900; white-space: nowrap; }.line-caption { margin: 36px 0 0; color: var(--muted); font-size: 9px; text-align: center; }
.result-combined { width: 100%; display: flex; flex-direction: column; align-items: center; gap: 2px; }

/* Práctica */
.practice-header-actions { display: flex; gap: 7px; }.practice-workspace { display: grid; grid-template-columns: 205px minmax(0,1fr); gap: 15px; align-items: start; }.practice-settings { padding: 19px 16px; }.segmented-control { display: grid; grid-template-columns: repeat(3,1fr); gap: 3px; margin-top: 12px; padding: 3px; border-radius: 9px; background: #f0f2f7; }.segment { border: 0; padding: 8px 2px; border-radius: 7px; color: var(--muted); background: transparent; font-size: 8px; font-weight: 800; }.segment.active { color: var(--blue); background: #fff; box-shadow: 0 2px 6px rgba(38,48,91,.07); }.level-heading { margin-top: 24px; }.level-option { display: grid; grid-template-columns: 13px 1fr; gap: 8px; align-items: center; margin-top: 12px; cursor: pointer; }.level-option input { position: absolute; opacity: 0; }.level-radio { width: 12px; height: 12px; border: 2px solid #d2d7e3; border-radius: 50%; }.level-option input:checked + .level-radio { border-color: var(--blue); box-shadow: inset 0 0 0 3px #fff; background: var(--blue); }.level-option strong, .level-option small { display: block; }.level-option strong { font-size: 9px; }.level-option small { margin-top: 3px; color: var(--pale); font-size: 8px; }.full-button { width: 100%; margin-top: 23px; }.practice-card { min-height: 550px; padding: 20px 26px 17px; text-align: center; }.practice-topline { display: flex; align-items: flex-start; justify-content: space-between; gap: 14px; text-align: left; }.question-progress { width: 135px; height: 5px; margin-top: 7px; }.score-pill { padding: 6px 9px; border-radius: 99px; color: #ae732d; background: var(--orange-soft); font-size: 9px; }.score-pill strong { font-size: 11px; }.practice-prompt { margin-top: 20px; }.question-label { color: var(--blue); font-size: 8px; letter-spacing: 1px; font-weight: 900; }.question-label b { color: var(--orange); }.practice-prompt h2 { margin: 8px 0 5px; font-size: 17px; letter-spacing: -.4px; }.large-number { min-height: 61px; margin: 3px 0; color: var(--ink); font-size: clamp(40px,6vw,59px); font-weight: 900; letter-spacing: -3px; }.practice-digit { display: inline-block; }.practice-digit.highlight { color: var(--blue); line-height: .9; border-bottom: 4px solid var(--orange); }.practice-prompt p { margin: 0; color: var(--muted); font-size: 9px; }.number-line-wrap { min-height: 101px; display: grid; place-items: center; }.practice-number-line { width: min(540px,100%); position: relative; padding: 34px 22px 7px; }.practice-number-line .line { height: 3px; position: relative; border-radius: 5px; background: #cbd1df; }.practice-number-line .line::after { content: ""; position: absolute; right: -4px; top: -5px; border-left: 10px solid #cbd1df; border-top: 7px solid transparent; border-bottom: 7px solid transparent; }.practice-number-line .tick-row { position: absolute; top: 25px; left: 22px; right: 22px; display: flex; justify-content: space-between; }.practice-number-line .tick { position: relative; width: 2px; height: 17px; background: #a5adbe; }.practice-number-line .tick small { position: absolute; top: 23px; left: 50%; transform: translateX(-50%); color: var(--pale); font-size: 8px; white-space: nowrap; }.practice-number-line .current-dot { position: absolute; top: 22px; width: 12px; height: 12px; border: 3px solid #fff; border-radius: 50%; background: var(--orange); box-shadow: 0 0 0 2px var(--orange); transform: translateX(-50%); }.practice-number-line .current-dot span { position: absolute; top: -28px; left: 50%; transform: translateX(-50%); color: var(--orange); font-size: 8px; font-weight: 900; white-space: nowrap; }.answer-grid { width: min(540px,100%); display: grid; grid-template-columns: repeat(4,1fr); gap: 9px; margin: 0 auto; }.answer-button, .challenge-option { min-height: 56px; border: 1px solid var(--line); border-radius: 12px; color: var(--ink); background: #fff; font-size: 16px; font-weight: 900; transition: transform .15s, border .15s, color .15s, background .15s; }.answer-button { position: relative; }.answer-button::before { content: attr(data-index); position: absolute; top: 6px; left: 8px; color: #bdc2ce; font-size: 8px; }.answer-button:hover, .challenge-option:hover { color: var(--blue); border-color: #cbd3fa; transform: translateY(-1px); }.answer-button.correct, .challenge-option.correct { color: #27815e; border-color: #b7e2cc; background: var(--green-soft); }.answer-button.incorrect, .challenge-option.incorrect { color: var(--red); border-color: #efc5c8; background: #fff2f2; }.practice-actions { width: min(540px,100%); display: flex; align-items: center; justify-content: space-between; gap: 10px; margin: 16px auto 0; }.hint-button { border: 0; padding: 8px 11px; color: #a86c20; background: var(--orange-soft); }.hint-button:hover { background: #ffe8c5; }.keyboard-tip { color: var(--pale); font-size: 8px; }.feedback-panel { width: min(540px,100%); margin: 13px auto 0; padding: 11px 13px; border: 1px solid var(--line); border-radius: 11px; color: var(--muted); font-size: 9px; line-height: 1.5; text-align: left; }.feedback-panel.success { color: #2a7959; border-color: #bee5cf; background: var(--green-soft); }.feedback-panel.try-again { color: #a35a5d; border-color: #f0c6c9; background: #fff2f2; }.feedback-panel strong { display: block; margin-bottom: 2px; font-size: 10px; }.feedback-panel button { float: right; border: 0; border-radius: 7px; padding: 5px 7px; color: var(--blue); background: #fff; font-size: 8px; font-weight: 900; }.session-complete { display: grid; place-items: center; }.session-complete-inner { max-width: 390px; padding: 25px; text-align: center; }.complete-emoji { font-size: 39px; }.session-complete-inner h2 { margin: 9px 0; font-size: 25px; }.session-complete-inner p { color: var(--muted); font-size: 10px; line-height: 1.6; }.complete-score { margin: 18px 0; color: var(--blue); font-size: 42px; font-weight: 900; }.complete-score small { color: var(--muted); font-size: 10px; }

/* Reto, progreso y ayuda */
.challenge-heading { align-items: center; }.challenge-badge { min-width: 67px; padding: 8px; border: 1px solid #f5e5ce; border-radius: 12px; color: #aa6f29; background: var(--orange-soft); text-align: center; }.challenge-badge span { display: block; font-size: 8px; font-weight: 900; letter-spacing: .8px; }.challenge-badge strong { display: block; margin-top: 2px; font-size: 20px; }.challenge-shell { min-height: 440px; padding: 38px 44px; }.challenge-intro { min-height: 350px; display: grid; grid-template-columns: .8fr 1.2fr; gap: 55px; align-items: center; max-width: 740px; margin: auto; }.challenge-number.n1 { width: 165px; height: 108px; display: grid; place-items: center; border-radius: 22px; color: #fff; background: var(--blue); font-size: 29px; font-weight: 900; transform: rotate(-7deg); box-shadow: 19px 20px 0 #eef1ff; }.challenge-intro h2 { max-width: 390px; margin: 8px 0 10px; font-size: 26px; letter-spacing: -1px; }.challenge-intro p { max-width: 390px; margin: 0 0 20px; color: var(--muted); font-size: 11px; line-height: 1.6; }.challenge-live { max-width: 650px; margin: auto; }.challenge-live-head { display: flex; align-items: center; gap: 16px; padding-bottom: 20px; border-bottom: 1px solid var(--line); }.timer-ring { width: 62px; height: 62px; display: grid; place-items: center; align-content: center; border: 4px solid var(--orange); border-left-color: #ffe5bd; border-radius: 50%; color: #a5651b; line-height: 1; }.timer-ring span { font-size: 19px; font-weight: 900; }.timer-ring small { font-size: 7px; }.challenge-live-head h2 { margin: 5px 0 0; font-size: 17px; }.challenge-live-score { margin-left: auto; text-align: right; }.challenge-live-score span { display: block; color: var(--pale); font-size: 8px; font-weight: 900; letter-spacing: .8px; }.challenge-live-score strong { display: block; color: var(--blue); font-size: 25px; }.challenge-question { padding: 30px 0 20px; text-align: center; }.challenge-number-live { color: var(--ink); font-size: clamp(43px,7vw,67px); font-weight: 900; letter-spacing: -3px; }.challenge-question p { color: var(--muted); font-size: 10px; }.challenge-options { width: min(530px,100%); display: grid; grid-template-columns: repeat(4,1fr); gap: 9px; margin: 20px auto; }.challenge-live > .quiet-button { display: block; margin: auto; }.challenge-result { max-width: 450px; margin: auto; padding: 25px 0 10px; text-align: center; }.result-medal { color: var(--green); font-size: 42px; }.challenge-result h2 { margin: 8px 0; font-size: 27px; }.challenge-result p { color: var(--muted); font-size: 10px; line-height: 1.6; }.result-stats { display: flex; justify-content: center; gap: 8px; margin: 21px 0; }.result-stats div { min-width: 85px; padding: 9px 6px; border: 1px solid var(--line); border-radius: 11px; background: #fcfcfe; }.result-stats strong { display: block; color: var(--blue); font-size: 19px; }.result-stats span { display: block; color: var(--muted); font-size: 8px; margin-top: 3px; }
.stats-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 10px; margin-bottom: 15px; }.stat-card { min-height: 105px; padding: 18px; border: 1px solid var(--line); border-radius: 15px; background: #fff; }.stat-card span { color: var(--muted); font-size: 9px; }.stat-card strong { display: block; margin-top: 14px; color: var(--blue); font-size: 28px; }.progress-detail-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 15px; }.mastery-card, .history-card { min-height: 325px; padding: 21px; }.mastery-card h2, .history-card h2 { margin: 6px 0 0; font-size: 17px; }.mastery-bars { display: grid; gap: 22px; margin-top: 27px; }.mastery-row { display: grid; gap: 7px; }.mastery-row-head { display: flex; justify-content: space-between; gap: 12px; }.mastery-row-head span { color: var(--muted); font-size: 9px; }.mastery-row-head strong { font-size: 11px; }.mastery-track { height: 8px; }.mastery-row small { color: var(--pale); font-size: 8px; }.history-list { margin-top: 19px; }.empty-history { display: grid; place-items: center; height: 210px; color: var(--pale); font-size: 9px; text-align: center; line-height: 1.5; }.history-item { display: flex; align-items: center; gap: 9px; padding: 10px 0; border-bottom: 1px solid #f0f1f5; }.history-item:last-child { border-bottom: 0; }.history-icon { width: 25px; height: 25px; display: grid; place-items: center; border-radius: 8px; color: var(--blue); background: var(--blue-soft); font-size: 11px; }.history-copy { min-width: 0; flex: 1; }.history-copy strong { display: block; font-size: 9px; }.history-copy small { display: block; margin-top: 3px; color: var(--pale); font-size: 8px; }.history-result { color: var(--green); font-size: 9px; font-weight: 900; }.library-grid { display: grid; grid-template-columns: minmax(0,1.35fr) minmax(220px,.65fr); gap: 15px; }.reference-card { padding: 16px; }.reference-card img { display: block; width: 100%; height: auto; border: 1px solid var(--line); border-radius: 12px; }.reference-card p, .glossary-card p { margin: 14px 0 0; color: var(--muted); font-size: 10px; line-height: 1.6; }.glossary-card { padding: 22px; background: var(--orange-soft); border-color: #f5e4ca; }.glossary-card h2 { margin: 10px 0 0; color: #86591f; font-size: 20px; letter-spacing: -.7px; }.glossary-card p { color: #a9793e; }
.toast-region { position: fixed; right: 22px; bottom: 22px; z-index: 50; display: grid; gap: 7px; max-width: min(300px,calc(100vw - 28px)); }.toast { padding: 10px 13px; border-radius: 10px; color: #fff; background: #26314f; box-shadow: 0 8px 20px rgba(20,30,70,.16); font-size: 9px; line-height: 1.45; }.toast.success { background: #2f8966; }.toast.warning { background: #aa6b23; }
.focus-mode .main-content { background: #f2f3f8; }.focus-mode .today-label { display: none; }

@media (max-width: 930px) {
  .screen-container { padding-left: 28px; padding-right: 28px; }.topbar { padding-left: 28px; padding-right: 28px; }.app-footer { padding-left: 28px; padding-right: 28px; }.minimal-hero { padding-left: 34px; padding-right: 34px; }.hero-example { min-width: 210px; transform: scale(.9); }.lesson-layout { grid-template-columns: 1fr; }.rule-aside { grid-template-columns: 1.2fr .8fr .8fr; }.practice-workspace { grid-template-columns: 185px minmax(0,1fr); }
}

@media (max-width: 720px) {
  .sidebar { width: 225px; align-items: stretch; transform: translateX(-105%); transition: transform .22s ease; box-shadow: 12px 0 32px rgba(24,33,73,.12); }.sidebar.open { transform: translateX(0); }.brand-wrap { justify-content: space-between; margin-bottom: 35px; }.brand-name { display: inline; }.sidebar-close { display: inline-grid; }.nav-item { justify-content: flex-start; padding: 10px 12px; }.nav-item > span:not(.nav-icon) { display: inline; }.sidebar-footer { justify-items: start; }.reset-link, .version-label { display: inline-block; padding-left: 12px; }.mobile-overlay { position: fixed; inset: 0; z-index: 19; background: rgba(25,32,67,.28); backdrop-filter: blur(2px); }.mobile-overlay.open { display: block; }.main-content { margin-left: 0; }.menu-button { display: inline-grid; }.topbar { min-height: 60px; padding-left: 16px; padding-right: 16px; }.breadcrumb { flex: 1; }.focus-button-label, .today-label { display: none; }.focus-button { width: 33px; height: 33px; padding: 0; justify-content: center; }.screen-container { padding: 28px 16px 15px; }.app-footer { flex-direction: column; gap: 4px; padding: 5px 16px 16px; }.minimal-hero { min-height: 0; padding: 29px 24px 32px; }.minimal-hero h1 { font-size: 34px; }.hero-example { display: none; }.home-actions { display: grid; }.home-actions button { width: 100%; }.four-steps { gap: 7px; justify-content: space-between; }.four-steps i { font-size: 10px; }.four-steps span { font-size: 8px; }.four-steps b { width: 21px; height: 21px; }.home-bottom, .target-tabs, .stats-grid, .progress-detail-grid, .library-grid { grid-template-columns: 1fr; }.page-heading { align-items: flex-start; flex-direction: column; margin-bottom: 18px; }.page-heading > button { align-self: flex-start; }.target-tab { padding: 10px 12px; }.rule-aside { grid-template-columns: 1fr; }.lesson-card { padding-left: 15px; padding-right: 15px; }.practice-header-actions { width: 100%; }.practice-header-actions .quiet-button { flex: 1; }.practice-workspace { grid-template-columns: 1fr; }.practice-card { order: 1; padding-left: 15px; padding-right: 15px; }.practice-settings { order: 2; }.answer-grid, .challenge-options { grid-template-columns: repeat(2,1fr); }.challenge-shell { padding: 24px 19px; }.challenge-intro { min-height: 330px; grid-template-columns: 1fr; gap: 22px; text-align: center; }.challenge-number.n1 { margin: 0 auto; }.challenge-intro p { margin-left: auto; margin-right: auto; }.challenge-heading { flex-direction: row; align-items: flex-start; }.challenge-live-head { gap: 10px; }.challenge-live-head h2 { font-size: 14px; }.timer-ring { width: 55px; height: 55px; }.result-stats { gap: 4px; }.result-stats div { min-width: 77px; }.micro-example { min-height: 0; }
}

@media (max-width: 470px) {
  .minimal-hero h1 { font-size: 30px; letter-spacing: -1.4px; }.minimal-hero p { font-size: 11px; }.four-steps span { display: none; }.four-steps { justify-content: center; gap: 12px; }.four-steps i { font-size: 12px; }.lesson-number-board { padding-left: 20px; padding-right: 20px; }.lesson-number-board .digit { font-size: 59px; }.rule-visual-board { gap: 5px; }.rule-visual-col { padding-left: 4px; padding-right: 4px; }.rule-visual-col .digit-set { font-size: 12px; letter-spacing: 0; }.rule-visual-middle { font-size: 20px; }.result-equation { gap: 7px; font-size: 38px; }.result-equation .equation-arrow { font-size: 24px; }.practice-actions { margin-top: 13px; }.keyboard-tip { display: none; }.challenge-intro h2 { font-size: 22px; }.challenge-badge { min-width: 58px; }.challenge-badge strong { font-size: 18px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; scroll-behavior: auto !important; transition-duration: .01ms !important; }
}

/* Lectura fácil: tamaño mayor y apoyo visual en las explicaciones. */
body { font-size: 16px; }
.eyebrow { font-size: 12px; letter-spacing: 1px; }
.breadcrumb { font-size: 12px; }
.today-label { font-size: 11px; }
.focus-button, .primary-button, .quiet-button, .text-button, .hint-button { font-size: 13px; }
.primary-button { padding: 13px 17px; }
.quiet-button { padding: 11px 14px; }
.minimal-hero h1 { font-size: clamp(36px, 4.5vw, 56px); }
.minimal-hero p, .page-heading p { font-size: 16px; line-height: 1.65; }
.four-steps span { font-size: 13px; }
.panel-title h2, .lesson-copy h2 { font-size: 23px; }
.example-panel p, .reference-card p, .glossary-card p { font-size: 14px; line-height: 1.65; }
.mini-progress-value span, .mini-progress-foot { font-size: 12px; }
.target-tab strong { font-size: 14px; }
.target-tab small { font-size: 12px; }
.lesson-progress-head { font-size: 12px; }
.lesson-copy .lesson-kicker { font-size: 12px; }
.lesson-copy p { font-size: 16px; line-height: 1.72; }
.explanation-picto { display: flex; flex-direction: column; align-items: center; gap: 4px; margin-bottom: 8px; }
.explanation-picto img { width: 70px; height: 70px; object-fit: contain; }
.explanation-picto span { color: var(--blue); font-size: 13px; font-weight: 900; }
.rule-picto { display: block; width: 48px; height: 48px; margin: 7px auto 2px; object-fit: contain; }
.rule-visual-col small { font-size: 10px; }
.rule-visual-col .digit-set { font-size: 17px; }
.rule-split strong { font-size: 12px; }
.rule-split small, .micro-example small { font-size: 11px; }
.rule-card p, .check-card p { font-size: 13px; line-height: 1.6; }
.check-card strong { font-size: 13px; }
.micro-example span { font-size: 11px; }
.micro-example strong { font-size: 24px; }
.question-label { font-size: 11px; }
.practice-prompt h2 { font-size: 22px; }
.practice-prompt p { font-size: 13px; }
.answer-button, .challenge-option { min-height: 64px; font-size: 20px; }
.feedback-panel { font-size: 13px; line-height: 1.6; }
.feedback-panel strong { font-size: 14px; }
.stat-card span { font-size: 12px; }
.history-copy strong { font-size: 12px; }
.history-copy small, .empty-history { font-size: 11px; }
.arasaac-credit { margin: 14px 2px 0; color: var(--pale); font-size: 11px; line-height: 1.55; }

@media (max-width: 720px) {
  .minimal-hero h1 { font-size: 37px; }
  .minimal-hero p { font-size: 16px; }
  .four-steps span { font-size: 11px; }
  .lesson-copy h2 { font-size: 22px; }
  .lesson-copy p { font-size: 16px; }
  .explanation-picto img { width: 64px; height: 64px; }
}

@media (max-width: 470px) {
  .minimal-hero h1 { font-size: 33px; }
  .minimal-hero p { font-size: 15px; }
  .four-steps span { display: none; }
  .lesson-copy p { font-size: 15px; }
  .rule-visual-col .digit-set { font-size: 13px; }
  .rule-picto { width: 42px; height: 42px; }
}

/* Fuente ampliada en toda la aplicación: más cómoda para lectura autónoma. */
body { font-size: 18px; }
.brand-name { font-size: 16px; }
.nav-item { font-size: 15px; }
.nav-icon { font-size: 18px; }
.reset-link { font-size: 13px; }
.version-label { font-size: 11px; }
.breadcrumb { font-size: 14px; }
.today-label { font-size: 13px; }
.focus-button { font-size: 14px; }
.app-footer { font-size: 12px; }
.eyebrow { font-size: 14px; line-height: 1.45; }
.minimal-hero h1 { font-size: clamp(40px, 5vw, 62px); }
.minimal-hero p, .page-heading p { font-size: 18px; line-height: 1.65; }
.primary-button, .quiet-button, .text-button, .hint-button { font-size: 15px; }
.primary-button { padding: 14px 18px; }
.quiet-button { padding: 12px 15px; }
.four-steps span { font-size: 15px; }
.four-steps b { font-size: 13px; }
.four-steps i { font-size: 18px; }
.panel-title h2 { font-size: 26px; }
.example-panel p, .reference-card p, .glossary-card p { font-size: 16px; line-height: 1.7; }
.rule-inline span:not(.rule-divider) { font-size: 20px; }
.rule-inline small { font-size: 13px; }
.mini-progress-value strong { font-size: 36px; }
.mini-progress-value span, .mini-progress-foot { font-size: 14px; }
.page-heading h1 { font-size: clamp(36px, 4vw, 48px); }
.target-tab strong { font-size: 16px; }
.target-tab small { font-size: 14px; }
.lesson-progress-head { font-size: 14px; }
.lesson-copy .lesson-kicker { font-size: 14px; }
.lesson-copy h2 { font-size: 27px; }
.lesson-copy p { font-size: 18px; line-height: 1.72; }
.board-label { font-size: 12px; }
.digit-caption { font-size: 12px; }
.rule-visual-col .digit-set { font-size: 20px; }
.rule-visual-col small { font-size: 12px; }
.rule-visual-middle { font-size: 30px; }
.line-tick span, .line-point small, .line-caption { font-size: 12px; }
.rule-split strong { font-size: 15px; }
.rule-split small, .micro-example small { font-size: 13px; }
.rule-card p, .check-card p { font-size: 15px; line-height: 1.65; }
.check-card strong { font-size: 15px; }
.micro-example span { font-size: 13px; }
.micro-example strong { font-size: 29px; }
.segment { font-size: 13px; }
.level-option strong { font-size: 14px; }
.level-option small { font-size: 13px; }
.question-label { font-size: 14px; }
.practice-prompt h2 { font-size: 26px; }
.practice-prompt p { font-size: 16px; }
.score-pill { font-size: 13px; }
.score-pill strong { font-size: 15px; }
.answer-button, .challenge-option { min-height: 70px; font-size: 23px; }
.answer-button::before { font-size: 11px; }
.feedback-panel { font-size: 16px; line-height: 1.65; }
.feedback-panel strong { font-size: 17px; }
.keyboard-tip { font-size: 12px; }
.challenge-badge span { font-size: 12px; }
.challenge-badge strong { font-size: 25px; }
.challenge-intro h2 { font-size: 31px; }
.challenge-intro p { font-size: 16px; line-height: 1.65; }
.timer-ring span { font-size: 23px; }
.timer-ring small { font-size: 11px; }
.challenge-live-head h2 { font-size: 21px; }
.challenge-live-score span { font-size: 11px; }
.challenge-live-score strong { font-size: 31px; }
.challenge-question p { font-size: 15px; }
.challenge-result h2 { font-size: 32px; }
.challenge-result p { font-size: 15px; line-height: 1.65; }
.result-stats strong { font-size: 23px; }
.result-stats span { font-size: 11px; }
.stat-card span { font-size: 15px; }
.stat-card strong { font-size: 34px; }
.mastery-card h2, .history-card h2 { font-size: 23px; }
.mastery-row-head span { font-size: 14px; }
.mastery-row-head strong { font-size: 16px; }
.mastery-row small { font-size: 13px; }
.empty-history { font-size: 14px; line-height: 1.65; }
.history-copy strong { font-size: 15px; }
.history-copy small { font-size: 13px; }
.history-result { font-size: 14px; }
.glossary-card h2 { font-size: 27px; }
.arasaac-credit { font-size: 13px; line-height: 1.65; }
.toast { font-size: 14px; line-height: 1.55; }
.hero-example small, .final-step-visual small { font-size: 12px; }
.rule-visual-middle small { font-size: 12px !important; }
.practice-number-line .tick small, .practice-number-line .current-dot span { font-size: 12px; }
.feedback-panel button { font-size: 12px; }
.session-complete-inner p { font-size: 15px; line-height: 1.65; }
.complete-score small { font-size: 13px; }
.history-icon { font-size: 15px; }

@media (max-width: 720px) {
  .nav-item { font-size: 16px; }
  .nav-icon { font-size: 19px; }
  .minimal-hero h1 { font-size: 40px; }
  .minimal-hero p { font-size: 18px; }
  .four-steps span { font-size: 13px; }
  .lesson-copy h2 { font-size: 25px; }
  .lesson-copy p { font-size: 17px; }
  .answer-button, .challenge-option { min-height: 72px; font-size: 22px; }
}

@media (max-width: 470px) {
  .minimal-hero h1 { font-size: 36px; }
  .minimal-hero p { font-size: 17px; }
  .lesson-copy p { font-size: 16px; }
  .question-label { font-size: 13px; }
  .practice-prompt h2 { font-size: 23px; }
  .practice-prompt p { font-size: 15px; }
  .glossary-card h2 { font-size: 24px; }
}