@font-face{font-family:system;src:local('Segoe UI')}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:24px}body{margin:0;background:#f5f5f0;color:#17263c;font-family:system,Arial,sans-serif;line-height:1.65}a{color:#984000}button,input{font:inherit}button,a{touch-action:manipulation}button{cursor:pointer}header{background:#101f35;color:white;padding:18px max(5vw,20px);display:flex;justify-content:space-between;align-items:center;gap:20px}.brand{color:white;text-decoration:none;display:flex;align-items:center;gap:12px;font-size:25px;font-weight:800;letter-spacing:3px}.brand img{width:44px;height:50px;object-fit:contain;background:white;border-radius:8px}.brand small{display:block;font-size:9px;letter-spacing:1.3px;font-weight:500}.badge,.eyebrow{font-size:11px;font-weight:800;letter-spacing:1.6px}.badge{border:1px solid #677a90;border-radius:24px;padding:6px 12px;color:#f8c57b}main{max-width:1160px;margin:auto;padding:32px 24px 70px}h1,h2,h3{line-height:1.18;letter-spacing:-.5px}h1{font-size:clamp(34px,5vw,60px);margin:18px 0;max-width:820px}h2{font-size:30px;margin:12px 0 22px}h3{font-size:21px}p{margin:12px 0}.hero{background:#152940;color:white;border-radius:24px;padding:clamp(26px,5vw,60px);position:relative;overflow:hidden}.hero:after{content:'';position:absolute;right:-60px;top:-140px;width:340px;height:340px;border:60px solid #f59c2522;border-radius:50%;pointer-events:none}.hero .eyebrow{color:#ffc47a}.hero p{max-width:660px;color:#d9e3ee;font-size:18px}.meta{display:flex;gap:12px;flex-wrap:wrap;font-size:13px;color:#dee7f2;margin:25px 0}.pill{background:#ffffff12;border:1px solid #ffffff38;border-radius:20px;padding:5px 13px}.button,button.primary{display:inline-block;background:#ffb449;color:#162236;border:0;text-decoration:none;padding:13px 20px;border-radius:10px;font-weight:750}.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;margin:24px 0}.tile{background:white;border:1px solid #dae0e4;border-radius:18px;overflow:hidden;display:flex;flex-direction:column}.tile .body{padding:24px;display:flex;flex-direction:column;flex:1}.tile .body p{flex:1}.tile .art{height:150px;background:#e8edf2;display:flex;align-items:center;justify-content:center;font-size:34px;color:#153b5c}.tile:nth-child(2) .art{background:#ffebcb;color:#7d4100}.tile:nth-child(3) .art{background:#dfeee8;color:#205b51}.tile h3{font-size:25px;margin:10px 0}.tile a{font-weight:750}.intro{margin:36px 0 20px}.section{background:white;border:1px solid #dde3e6;border-radius:18px;padding:32px;margin:0 0 22px}.section .eyebrow{color:#975117}.objective{border-left:4px solid #d7811c;padding:2px 0 2px 18px}.callout{background:#fff4e4;border-left:4px solid #da8b2d;padding:16px 22px;border-radius:0 12px 12px 0;margin:22px 0}.theory-block{border-top:1px solid #e7e9eb;padding-top:12px;margin-top:24px}.example{background:#f2f6fa;padding:20px;border-radius:12px;margin:16px 0}.example h3{margin:0 0 12px}.question{padding:22px 0;border-top:1px solid #e2e7eb}.question fieldset{border:0;padding:0;margin:0;min-width:0}.question legend{font-weight:700;margin-bottom:12px;width:100%}.option{display:flex;align-items:center;gap:10px;padding:12px;border:1px solid #ccd6df;border-radius:9px;margin:8px 0;cursor:pointer}.option:has(input:checked){background:#eaf1f9;border-color:#416687}.option input{flex-shrink:0;width:18px;height:18px;accent-color:#194c75}.question button{margin-top:10px;background:#173651;color:white;border:0;border-radius:8px;padding:10px 16px}.feedback{padding:12px 16px;border-radius:8px;background:#eef4f7;margin-top:12px}.correct{background:#e4f4ec;color:#18543d}.incorrect{background:#fff1e4;color:#713b17}details{margin:12px 0;background:#f3f6f8;border-radius:9px;padding:12px 16px}summary{cursor:pointer;font-weight:650}.score{font-weight:700;padding:18px;background:#edf2f7;border-radius:10px;margin-top:18px}.visual{background:#eef4f6;border-radius:14px;padding:20px;margin:24px 0}.visual svg{width:100%;height:auto;max-height:220px}.visual label{font-weight:700}.visual input{width:100%;accent-color:#a95410}.visual output{display:block;font-size:19px;font-weight:700}.katex-display{overflow-x:auto;overflow-y:hidden;padding:8px 0}.katex{font-size:1.12em}.back{display:inline-block;margin-bottom:20px}footer{text-align:center;padding:24px;background:#e7ecef;color:#3c5267;font-size:14px}.skip{position:absolute;top:-100px;background:white;padding:12px;z-index:10}.skip:focus{top:0}:focus-visible{outline:3px solid #b56308;outline-offset:4px}.muted{color:#5c6b7a;font-size:14px}.source-note{font-size:13px;color:#536578}button:disabled{opacity:.6;cursor:default}@media(max-width:760px){header{padding:14px 18px}.badge{display:none}main{padding:20px 14px 45px}.grid{grid-template-columns:1fr}.tile .art{height:110px}.section{padding:22px 18px}h2{font-size:25px}.hero{border-radius:16px}.hero p{font-size:16px}.brand small{font-size:8px}.meta{font-size:12px}}

.parabola svg{display:block;width:100%;max-width:600px;height:auto;max-height:none;margin:12px auto 4px;font-family:Arial,sans-serif;font-size:16px;color:#324c63}.parabola .axis{stroke:#52677a;stroke-width:1.4;fill:none}.parabola .gridline{stroke:#d8e3e8;stroke-width:1}.parabola .guide{stroke:#a84b06;stroke-width:1.5;stroke-dasharray:5 5;fill:none}.graph-legend{display:flex;gap:20px;justify-content:center;flex-wrap:wrap;font-size:14px}.vertex-key{color:#a84b06}.moving-key{color:#7c3890}.graph-reading{border-top:1px solid #cbd9df;margin-top:22px;padding-top:20px}.question legend{line-height:1.9}.option{min-height:54px}.question .katex{font-size:1.16em}@media(max-width:480px){.parabola{padding:12px}.parabola svg{font-size:19px}.graph-legend{gap:10px;font-size:13px}}


.parabola h3{margin:0 0 .35em}
.parabola>p{margin:0 0 .4em}
.parabola svg{width:min(100%,480px,56svh);height:auto;margin:4px auto}
.parabola .graph-legend{margin-bottom:6px}
.parabola #slider{display:block;margin:4px 0}


.lesson-body { margin-top:20px }
.route-nav { display:flex; align-items:center; gap:18px; background:white; border:1px solid #d4dfe5; border-radius:14px; padding:8px 16px; margin-bottom:16px }
.route-label,.route-toggle { font-weight:700; color:#173651 }
.route-toggle { display:none }
#route-links { display:flex; flex:1; justify-content:space-between; gap:6px }
#route-links a { display:block; text-decoration:none; color:#273e54; padding:10px 8px; border-radius:8px }
#route-links a:hover,#route-links a:focus-visible { background:#edf3f6 }
.theory-steps { list-style:none; padding:0; margin:20px 0; display:grid; gap:16px }
.theory-steps li { min-width:0; border-top:2px solid #d6e0e6; padding:12px 0 0 }
.theory-steps h3 { margin:7px 0 }
.step-number { display:inline-block; color:#874415; font-weight:700; font-size:.86em }
#teoria { container: theory / inline-size }
.theory-steps { grid-template-columns:minmax(0,1fr) }
.theory-steps p { overflow-wrap:break-word }
.theory-steps .katex-html { white-space:normal }
@container theory (min-width: 52rem) {
 .theory-steps { grid-template-columns:repeat(2,minmax(0,1fr)); gap:1.25rem 2rem }
}
@media(max-width:1024px){
 .route-nav { display:block; padding:4px 12px }
 .route-label { display:none }
 .route-toggle { display:flex; width:100%; justify-content:space-between; align-items:center; background:none; border:0; padding:10px 4px; text-align:left; min-height:44px }
 .route-toggle[aria-expanded=true] span { transform:rotate(180deg) }
 #route-links { display:none }
 .route-toggle[aria-expanded=true]+#route-links { display:grid; grid-template-columns:repeat(auto-fit,minmax(135px,1fr)); padding:6px 0; border-top:1px solid #d4dfe5 }
}


@media(max-height:720px){.parabola svg{width:min(100%,480px,50svh)}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}


#practica, #evaluacion { container-type:inline-size }
.question-grid { display:grid; grid-template-columns:minmax(0,1fr); gap:16px; margin-top:20px }
.question-grid .question { min-width:0; padding:18px; border:1px solid #d9e2e8; border-radius:12px }

@container (min-width:700px) {
 .question-grid { grid-template-columns:repeat(2,minmax(0,1fr)) }
}


.formula-sheet{background:#f2f6f9;border:1px solid #d5dfe6;border-radius:14px;padding:clamp(14px,2.6vw,26px);margin:18px 0 24px;container-type:inline-size}
.formula-sheet h3{margin:6px 0}.formula-grid{display:grid;grid-template-columns:minmax(0,1fr);gap:12px;margin-top:16px}
.formula-grid article{min-width:0;background:white;border-inline-start:3px solid #c77722;padding:12px 14px;border-radius:6px}
.formula-grid h4{margin:0;color:#173651}.formula-grid p{font-size:14px;margin:6px 0 0}
.formula-equation .katex-display{margin:4px 0;text-align:left}.formula-equation .katex-display>.katex{text-align:left}
.formula-jump{display:inline-block;color:white;margin:8px 12px}
.formula-mobile{display:none}
@container (max-width:27rem){.formula-desktop{display:none}.formula-mobile{display:inline}}


.formula-equation{line-height:2.15;padding:8px 0;min-width:0}
.formula-equation .katex-html{white-space:normal}


/* Only mathematical glyphs change size. Prose keeps its own reading scale. */
.section .katex { font-size:1.25em }
.formula-equation .katex { font-size:clamp(1.35rem,2vw,1.65rem) }
@media(max-width:480px) {
 .formula-grid article { padding-inline:8px }
 .formula-equation .katex { font-size:1.33rem }
 .theory-steps li { display:block }
}

.lesson-hero { container: lesson-cover / inline-size; isolation:isolate }
.lesson-hero::after { z-index:-1 }
.hero-pair { display:grid; grid-template-columns:minmax(0,1fr); gap:16px; align-items:center }
.hero-equation { justify-self:start; width:fit-content; max-width:100%; min-width:0; margin:0; padding:clamp(12px,2vw,22px); background:#203952; border:1px solid #566a7b; border-inline-start:3px solid #efab50; border-radius:12px }
.hero-equation figcaption { font-size:.875rem; font-weight:650; color:#ffcf88; margin-bottom:6px }
.hero-math { line-height:1.9; color:#fff }
.hero-math .katex { font-size:clamp(1.32rem,3.6cqi,1.85rem) }
.hero-math .katex-html { white-space:normal }
.hero-equation small { display:block; color:#e0e8ee; margin-top:6px }

@container lesson-cover (min-width:55rem){ .hero-math .katex{font-size:1.48rem} }
.hero-math { padding-inline-end:.25em }

/* Course catalogue: one stage at a time prevents an endless vertical wall. */
.catalog-hero{margin-bottom:18px}.hero-actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:18px}
.stage-tabs{display:flex;gap:8px;overflow-x:auto;padding:4px 2px 14px;margin:0 auto;max-width:1180px;scrollbar-width:thin}
.stage-tab{flex:0 0 auto;border:1px solid #cad8e2;border-radius:999px;padding:10px 15px;background:#fff;color:#1d3d58;font-weight:750;text-decoration:none;white-space:nowrap}
.stage-tab:hover,.stage-tab:focus-visible{border-color:#bb6415;background:#fff2dc;outline:none}.stage-tab.is-active{background:#173651;border-color:#173651;color:#fff}
.catalog-stage{max-width:1180px;margin:0 auto 28px;background:#fff;border:1px solid #d5dfe6;border-radius:18px;padding:clamp(18px,3vw,32px)}
.catalog-stage-heading{display:flex;align-items:flex-start;justify-content:space-between;gap:18px;border-bottom:1px solid #d9e3ea;padding-bottom:18px;margin-bottom:18px}.catalog-stage-heading h2{margin:5px 0}.catalog-stage-heading p{margin:0;max-width:700px}.stage-progress{flex:0 0 auto;color:#6b4a20;background:#fff2dc;border-radius:999px;padding:7px 10px;font-size:.9rem;font-weight:750}
.module-catalog{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.module-card{min-width:0;border:1px solid #d5dfe6;border-radius:12px;padding:18px;background:#fff;display:flex;flex-direction:column}.module-card-head{display:flex;justify-content:space-between;gap:10px;align-items:center}.module-number{font-size:.82rem;font-weight:800;letter-spacing:.06em;text-transform:uppercase;color:#a3520d}.module-status{font-size:.82rem;color:#526a7b;background:#edf3f6;padding:4px 7px;border-radius:999px;white-space:nowrap}.module-card h3{margin:9px 0 10px;color:#102e49}.module-lesson-list{list-style:none;padding:0;margin:0 0 14px;display:grid;gap:5px}.module-lesson-list a{display:flex;align-items:baseline;gap:8px;color:#244d70;text-decoration:none;line-height:1.35}.module-lesson-list a:hover{text-decoration:underline}.module-lesson-list a span{font-variant-numeric:tabular-nums;color:#b15a10;font-size:.8rem;font-weight:800}.text-link{margin-top:auto;color:#a3520d;font-weight:800;text-decoration:none}.text-link:hover{text-decoration:underline}
@media(max-width:680px){.catalog-stage-heading{display:block}.stage-progress{display:inline-block;margin-top:12px}.module-catalog{grid-template-columns:minmax(0,1fr)}.catalog-stage{border-radius:12px}.stage-tabs{margin-inline:-2px;padding-inline:2px}}