:root {
  color-scheme: light;
  --paper: #f6f5ed;
  --card: #fffef8;
  --soft: #ecefe5;
  --ink: #193a34;
  --text: #273e37;
  --muted: #52665e;
  --border: #dce2d6;
  --strong-border: #a8b9a9;
  --brand: #194a41;
  --accent: #c2d980;
  --accent-dark: #24451f;
  --focus: #036e90;
  --hero: #173e37;
  --hero-ink: #f9fbeb;
  --hero-soft: #c4d8c8;
  --green-bg: #e8eed8;
  --green-ink: #30562c;
  --orange-bg: #f7e8d8;
  --orange-ink: #764519;
  --blue-bg: #e1edf0;
  --blue-ink: #275369;
  --purple-bg: #eee8f0;
  --purple-ink: #614768;
  --incorrect-bg: #fae9e1;
  --incorrect-ink: #773b2c;
  --radius: 16px;
  --shell: 1120px;
  --mono: ui-monospace, "Cascadia Code", Consolas, monospace;
  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  --shadow: 0 9px 22px rgb(22 49 38 / 7%);
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --paper: #141f1c;
  --card: #1b2a25;
  --soft: #23362e;
  --ink: #e4f0df;
  --text: #d4e3d8;
  --muted: #adc2b7;
  --border: #365044;
  --strong-border: #577765;
  --brand: #d4e9b0;
  --accent: #c2d980;
  --accent-dark: #24451f;
  --focus: #8ad8ee;
  --hero: #193c35;
  --green-bg: #2b4230;
  --green-ink: #d2e9af;
  --orange-bg: #453328;
  --orange-ink: #f0c69b;
  --blue-bg: #233c49;
  --blue-ink: #b6deed;
  --purple-bg: #3d3043;
  --purple-ink: #e1c6e6;
  --incorrect-bg: #4b322d;
  --incorrect-ink: #f4c1af;
  --shadow: 0 9px 22px rgb(0 0 0 / 15%);
}
* { box-sizing: border-box; }
html { scroll-padding-top: 96px; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.55;
}
[hidden] { display: none !important; }
.print-only { display: none; }
button, input { font: inherit; }
button { cursor: pointer; }
button[aria-disabled="true"] { cursor: default; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 4px; }
:focus:not(:focus-visible) { outline: none; }
a { color: var(--brand); text-underline-offset: .18em; }
a:hover { text-decoration-thickness: 2px; }
h1, h2, h3, p { margin: 0; }
h1, h2, h3 { color: var(--ink); line-height: 1.1; text-wrap: balance; }
h1 { font-size: clamp(2.25rem, 5.2vw, 4rem); letter-spacing: -.065em; font-weight: 780; }
h2 { font-size: clamp(1.5rem, 3.2vw, 2.2rem); letter-spacing: -.045em; font-weight: 750; }
h3 { font-size: 1.2rem; letter-spacing: -.025em; font-weight: 730; }
strong { font-weight: 730; }
svg { display: block; max-width: 100%; }
.shell { width: min(var(--shell), calc(100% - 64px)); margin-inline: auto; }
#conteudo { min-height: 62vh; padding-block: 32px 64px; }
.initial-loading { padding-block: 40px; color: var(--muted); }
.icon {
  width: 19px;
  height: 19px;
  flex: 0 0 auto;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.75;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.sr-only, .skip-link:not(:focus) {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}
.skip-link:focus {
  position: fixed;
  top: 10px;
  left: 12px;
  z-index: 5;
  background: var(--card);
  padding: 10px 14px;
  border-radius: 8px;
}
.eyebrow {
  color: var(--muted);
  font: 700 .72rem/1.4 var(--mono);
  letter-spacing: .105em;
  text-transform: uppercase;
}
.muted { color: var(--muted); }
.lede { color: var(--muted); font-size: clamp(1.04rem, 2vw, 1.25rem); max-width: 67ch; }
.inline-icon { display: inline-flex; gap: 7px; align-items: center; }
.button, .icon-button {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  border-radius: 9px;
  border: 1px solid transparent;
  text-decoration: none;
  padding: 9px 14px;
  color: var(--ink);
  font-weight: 680;
  font-size: .9rem;
  line-height: 1.2;
  background: transparent;
}
.button:hover, .icon-button:hover { text-decoration: none; }
.button-primary { color: var(--card); background: var(--ink); }
.button-primary:hover { box-shadow: var(--shadow); }
.button-quiet { border-color: var(--strong-border); background: var(--card); }
.button-quiet:hover, .button-subtle:hover, .icon-button:hover { background: var(--soft); }
.button-subtle { color: var(--muted); text-decoration: underline; }
.button[aria-disabled="true"] { color: var(--muted); border-style: dashed; background: var(--soft); }
.site-header {
  position: sticky;
  top: 0;
  z-index: 3;
  background: var(--paper);
  border-bottom: 1px solid var(--border);
}
.site-header-inner {
  min-height: 68px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto auto;
  align-items: center;
  gap: 24px;
}
.brand {
  display: inline-flex;
  width: fit-content;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-size: 1rem;
  font-weight: 650;
  letter-spacing: -.035em;
  text-decoration: none;
}
.brand strong { font-weight: 780; }
.brand-mark { width: 38px; height: 38px; flex-shrink: 0; }
.site-nav { display: flex; gap: 4px; align-items: center; }
.site-nav a {
  display: flex;
  align-items: center;
  min-height: 44px;
  border-radius: 8px;
  padding: 8px 13px;
  color: var(--muted);
  text-decoration: none;
  font-size: .9rem;
  font-weight: 660;
}
.site-nav a:hover, .site-nav [aria-current] { color: var(--ink); background: var(--soft); }
.icon-button { width: 44px; padding: 0; border-color: var(--border); }
.notice {
  margin-top: 20px;
  padding: 12px 16px;
  border: 1px solid var(--strong-border);
  border-radius: 10px;
  color: var(--orange-ink);
  background: var(--orange-bg);
}
.site-footer { border-top: 1px solid var(--border); }
.footer-inner {
  padding-block: 24px 28px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  font-size: .88rem;
  color: var(--muted);
}
.footer-inner strong { color: var(--ink); }
.footer-inner nav { display: flex; flex-wrap: wrap; column-gap: 22px; align-items: center; }

.hero {
  display: grid;
  grid-template-columns: 1.24fr 1fr;
  align-items: stretch;
  isolation: isolate;
  overflow: hidden;
  color: var(--hero-ink);
  background: var(--hero);
  border: 1px solid #2f6154;
  border-radius: 22px;
}
.hero-copy { position: relative; z-index: 1; padding: clamp(32px, 4.3vw, 58px); padding-right: 12px; }
.hero-kicker { display: flex; align-items: center; gap: 10px; color: var(--hero-soft); }
.status-dot { width: 8px; height: 8px; border-radius: 50%; background: #dbeaa0; box-shadow: 0 0 0 4px rgb(219 234 160 / 12%); }
.hero h1 { margin-top: 14px; color: var(--hero-ink); font-size: clamp(2.8rem, 5.75vw, 4.85rem); line-height: .99; letter-spacing: -.072em; text-wrap: initial; }
.hero h1 span { display: block; color: #e0eaa9; }
.hero-lede { max-width: 45ch; color: var(--hero-soft); font-size: 1.03rem; margin-top: 17px; }
.hero-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 8px 17px; margin-top: 22px; }
.hero-button { background: #dbeaa0; color: #213b2a; }
.hero-button:hover { background: #f0f4bb; }
.hero-lab-link { display: inline-flex; min-height: 44px; gap: 7px; align-items: center; color: var(--hero-ink); font-size: .9rem; font-weight: 650; text-decoration: none; }
.hero-lab-link:hover { text-decoration: underline; }
.hero :focus-visible { outline-color: #a6d9ee; }
.hero-artwork { display: grid; place-items: center; background: radial-gradient(ellipse at center, #255349, transparent 74%); padding: 6px 12px 6px 0; }
.hero-art { width: 100%; max-width: 474px; height: auto; }
.hero-stats {
  margin-block: 13px 38px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border: 1px solid var(--border);
  border-radius: 13px;
  background: var(--card);
}
.hero-stats > div {
  min-width: 0;
  display: flex;
  gap: 9px;
  align-items: baseline;
  justify-content: center;
  padding: 12px 9px;
}
.hero-stats > div + div { border-left: 1px solid var(--border); }
.hero-stats strong { color: var(--ink); font-size: 1.45rem; letter-spacing: -.045em; }
.hero-stats span { color: var(--muted); font-size: .86rem; }
.resume-strip {
  margin-block: -16px 34px;
  display: grid;
  align-items: center;
  gap: 14px;
  grid-template-columns: auto 1fr auto;
  padding: 16px 18px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--green-bg);
}
.resume-strip strong { color: var(--ink); }
.resume-strip .muted { font-size: .88rem; }
.resume-icon { display: grid; place-items: center; width: 42px; height: 42px; background: var(--card); border-radius: 10px; color: var(--green-ink); }
.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px 24px;
  margin-bottom: 17px;
}
.section-heading h2, .search-top h2 { margin-top: 3px; }
.section-heading > p { max-width: 46ch; color: var(--muted); font-size: .93rem; }
.grade-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; }
.grade-card {
  display: flex;
  min-width: 0;
  flex-direction: column;
  padding: 15px 15px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--card);
  color: var(--ink);
  text-decoration: none;
  transition: border-color .15s ease, box-shadow .15s ease, transform .15s ease;
}
.grade-card:hover { border-color: var(--strong-border); box-shadow: var(--shadow); transform: translateY(-2px); }
.grade-top { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 11px; }
.diagram-tile { display: grid; place-items: center; width: 48px; height: 44px; flex-shrink: 0; border-radius: 10px; background: var(--soft); }
.diagram-tile .diagram { width: 39px; height: 34px; }
[data-tone="green"] { background: var(--green-bg); color: var(--green-ink); }
[data-tone="orange"] { background: var(--orange-bg); color: var(--orange-ink); }
[data-tone="blue"] { background: var(--blue-bg); color: var(--blue-ink); }
[data-tone="purple"] { background: var(--purple-bg); color: var(--purple-ink); }
.grade-index { color: var(--muted); font: 650 .73rem var(--mono); }
.grade-year { color: var(--muted); font-size: .78rem; font-weight: 670; }
.grade-title { font-size: 1.32rem; letter-spacing: -.042em; line-height: 1.2; margin-top: 2px; }
.grade-subtitle { flex: 1; margin-block: 5px 12px; font-size: .88rem; line-height: 1.4; color: var(--muted); }
.grade-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 4px;
  padding-top: 8px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: .78rem;
  font-weight: 680;
}
.grade-bottom .icon { color: var(--brand); }
.search-panel { margin-top: 38px; border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; background: var(--soft); }
.search-top { display: grid; grid-template-columns: 1fr minmax(210px, .9fr); align-items: end; gap: 16px; }
.search-field { position: relative; }
.search-field .icon { position: absolute; top: 14px; left: 14px; color: var(--muted); pointer-events: none; }
.search-field input {
  width: 100%;
  min-height: 46px;
  padding: 8px 12px 8px 42px;
  border: 1px solid var(--strong-border);
  border-radius: 9px;
  background: var(--card);
  color: var(--ink);
}
.search-field input::placeholder { color: var(--muted); }
.search-count:not(:empty) { margin-block: 14px 8px; font-size: .9rem; color: var(--muted); }
.breadcrumbs { margin-bottom: 17px; }
.breadcrumbs ol { list-style: none; display: flex; flex-wrap: wrap; gap: 3px 10px; padding: 0; margin: 0; color: var(--muted); font-size: .88rem; }
.breadcrumbs li + li::before { content: "/"; padding-right: 10px; color: var(--muted); }
.page-heading { display: grid; gap: 10px; margin-bottom: 24px; }
.series-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 20px;
  padding: 25px 30px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--card);
}
.series-hero .page-heading { margin: 0; }
.series-badge, .lesson-hero-tile { display: grid; place-items: center; width: 130px; height: 110px; border-radius: 14px; }
.series-badge { background: var(--green-bg); color: var(--green-ink); }
.series-badge .diagram, .lesson-hero-tile .diagram { width: 94px; }
.series-status {
  display: grid;
  grid-template-columns: auto minmax(80px, 1fr) auto;
  align-items: center;
  gap: 14px;
  padding: 12px 14px;
  margin: 11px 0 29px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--soft);
  font-size: .86rem;
  font-weight: 650;
}
progress {
  appearance: none;
  display: block;
  width: 100%;
  min-width: 0;
  height: 8px;
  overflow: hidden;
  border: 0;
  border-radius: 10px;
  background: var(--border);
  color: var(--brand);
}
progress::-webkit-progress-bar { background: var(--border); border-radius: 10px; }
progress::-webkit-progress-value { background: var(--brand); border-radius: 10px; }
progress::-moz-progress-bar { background: var(--brand); border-radius: 10px; }
.term-section + .term-section { margin-top: 25px; }
.term-heading { display: flex; align-items: center; gap: 12px; margin-bottom: 10px; }
.term-heading h2 { font-size: 1.32rem; }
.term-heading p { font-size: .83rem; }
.term-number {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--soft);
  color: var(--brand);
  font: 700 .88rem var(--mono);
}
.lesson-list { display: grid; gap: 7px; }
.lesson-row {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 13px;
  padding: 11px 14px;
  border: 1px solid var(--border);
  border-radius: 11px;
  background: var(--card);
  color: var(--ink);
  text-decoration: none;
}
.lesson-row:hover, .progress-row:hover { border-color: var(--strong-border); box-shadow: var(--shadow); }
.lesson-row-copy { display: grid; gap: 2px; min-width: 0; }
.lesson-row-copy strong { line-height: 1.25; }
.lesson-row-meta { color: var(--muted); font-size: .78rem; font-weight: 650; }
.lesson-row-summary { color: var(--muted); font-size: .86rem; line-height: 1.35; }
.lesson-row-end { display: flex; align-items: center; gap: 10px; color: var(--muted); font-size: .82rem; }
.lesson-row-end .icon { color: var(--brand); }
.pill { display: inline-flex; align-items: center; width: fit-content; border-radius: 20px; padding: 4px 10px; font-size: .77rem; font-weight: 700; }
.status-pill { background: var(--soft); color: var(--ink); }
.status-pill[data-status="mastered"] { background: var(--green-bg); color: var(--green-ink); }
.series-footnote { margin-top: 22px; font-size: .88rem; color: var(--muted); }

.lesson-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 20px;
  padding: clamp(18px, 3.5vw, 38px);
  border: 1px solid var(--border);
  border-radius: 17px;
  background: var(--card);
}
.lesson-header h1 { margin-block: 7px 9px; }
.lesson-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 13px; margin-top: 17px; font-size: .89rem; color: var(--muted); }
.lesson-layout { display: grid; grid-template-columns: 184px minmax(0, 1fr); align-items: start; gap: clamp(20px, 4vw, 50px); margin-top: 24px; }
.lesson-rail { position: sticky; top: 87px; }
.rail-card { padding: 14px 10px 10px; border: 1px solid var(--border); border-radius: 12px; background: var(--card); }
.rail-card > .eyebrow { padding-inline: 8px; margin-bottom: 5px; }
.rail-links { display: grid; gap: 1px; }
.rail-link {
  padding: 8px;
  min-height: 42px;
  border: 0;
  border-radius: 7px;
  text-align: left;
  color: var(--ink);
  background: transparent;
  font-size: .9rem;
  font-weight: 650;
}
.rail-link:hover { background: var(--soft); }
.rail-foot { display: grid; gap: 8px; margin-top: 8px; padding-top: 9px; border-top: 1px solid var(--border); }
.rail-foot p { padding-inline: 8px; font-size: .8rem; }
.rail-foot .button { width: 100%; }
.lesson-content { width: 100%; max-width: 792px; min-width: 0; }
.lesson-content h2 { font-size: clamp(1.45rem, 3.4vw, 1.9rem); }
.lesson-content > * + * { margin-top: 24px; }
.lesson-objectives { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.lesson-objectives > section { padding: 15px; border: 1px solid var(--border); border-radius: 12px; background: var(--card); }
.lesson-objectives h2 { font-size: 1.1rem; }
.text-list { margin-block: 9px 0; padding-inline-start: 1.35rem; }
.text-list li + li { margin-top: 5px; }
.explanation h2, .lesson-quiz h2, .callout h2 { margin-top: 3px; }
.explanation > section { margin-top: 16px; }
.explanation h3 { margin-bottom: 6px; }
.explanation p + p { margin-top: 8px; }
.callout {
  padding: 17px 18px;
  border: 1px solid var(--border);
  border-left: 4px solid var(--strong-border);
  border-radius: 11px;
  background: var(--card);
}
.activity-callout { border-left-color: #739e62; background: var(--green-bg); }
.misconception-callout { border-left-color: #c38855; background: var(--orange-bg); }
.example-callout { border-left-color: #649eb2; background: var(--blue-bg); }
.callout h3 { font-size: 1rem; margin-top: 13px; }
.callout p:not(.eyebrow) { margin-top: 6px; }
.example-question { color: var(--ink); font-weight: 700; }
.lesson-quiz { margin-top: 34px; }
.lesson-quiz > p:nth-of-type(2) { margin-top: 7px; }
.quiz-meter {
  padding: 11px 13px;
  margin: 12px 0 16px;
  border: 1px solid var(--border);
  border-radius: 9px;
  background: var(--soft);
}
.quiz-status { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 2px 10px; margin-bottom: 6px; font-size: .86rem; }
.quiz-status strong { color: var(--ink); }
.question {
  min-inline-size: 0;
  margin: 18px 0 0;
  padding: 11px 13px 13px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--card);
}
.question legend {
  max-width: 100%;
  padding-inline: 4px;
  color: var(--ink);
  font-weight: 730;
  line-height: 1.4;
  overflow-wrap: anywhere;
}
.question-number {
  display: inline-block;
  vertical-align: .09em;
  margin-right: 6px;
  padding: 3px 5px;
  border-radius: 5px;
  background: var(--soft);
  color: var(--brand);
  font: 700 .75rem var(--mono);
}
.answer-options { display: grid; gap: 6px; }
.answer-option {
  display: grid;
  grid-template-columns: auto auto minmax(0, 1fr);
  align-items: center;
  gap: 8px;
  min-height: 46px;
  padding: 6px 8px;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
}
.answer-option:has(input:not(:disabled)):hover { background: var(--soft); border-color: var(--strong-border); }
.answer-option:has(input:checked) { border-color: var(--strong-border); background: var(--soft); }
.answer-option:has(input:disabled) { cursor: default; }
.answer-option input { margin: 0; accent-color: var(--brand); width: 1rem; height: 1rem; }
.answer-option input:focus-visible { outline-offset: 2px; }
.answer-option[data-result="correct"], .answer-feedback[data-result="correct"] { background: var(--green-bg); color: var(--green-ink); }
.answer-option[data-result="incorrect"], .answer-feedback[data-result="incorrect"] { background: var(--incorrect-bg); color: var(--incorrect-ink); }
.answer-letter {
  display: grid;
  place-items: center;
  width: 25px;
  height: 25px;
  border-radius: 6px;
  color: var(--brand);
  background: var(--soft);
  font: 700 .77rem var(--mono);
}
.answer-option-text { overflow-wrap: anywhere; }
.question-actions { margin-top: 10px; }
.answer-feedback:not(:empty) { margin-top: 9px; padding: 9px 11px; border-radius: 8px; }
.answer-feedback p { margin-top: 3px; }
.lesson-reset { margin-top: 10px; }
.answer-key details {
  margin-top: 8px;
  padding: 12px 15px;
  border: 1px solid var(--border);
  border-radius: 11px;
  background: var(--card);
}
.answer-key summary { padding-block: 8px; color: var(--brand); font-weight: 700; cursor: pointer; }
.answer-key ol { list-style: none; padding: 0; margin: 10px 0 0; }
.answer-key li { padding: 11px 0; border-top: 1px solid var(--border); }
.answer-key h3 { font-size: 1.02rem; }
.answer-key-correct { font-weight: 700; color: var(--green-ink); margin-block: 4px 2px; }
.lesson-sources { padding-top: 14px; border-top: 1px solid var(--border); }
.lesson-sources > a { display: inline-block; margin-top: 8px; }
.lesson-footer-nav { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px; margin-top: 23px; }

.progress-totals { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 9px; margin-bottom: 27px; }
.progress-totals > div { display: grid; gap: 1px; padding: 16px; border: 1px solid var(--border); border-radius: 11px; background: var(--card); }
.progress-totals strong { color: var(--ink); font-size: clamp(1.5rem, 4vw, 2.6rem); letter-spacing: -.07em; line-height: 1; }
.progress-totals span { color: var(--muted); font-size: .9rem; }
.progress-list-title { margin-bottom: 10px; }
.progress-series { display: grid; gap: 6px; }
.progress-row {
  display: grid;
  grid-template-columns: 135px minmax(70px, 1fr) auto auto;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--card);
  color: var(--ink);
  text-decoration: none;
}
.progress-row > div { display: grid; }
.progress-row .muted, .progress-row-count { font-size: .84rem; }
.data-panel { margin-top: 22px; padding: 17px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--soft); }
.data-panel h2 { font-size: 1.4rem; }
.data-panel p:not(:empty) { margin-top: 6px; }
.action-row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.import-status:not(:empty) { font-weight: 680; color: var(--brand); }
.source-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr); gap: 20px; }
.source-grid h2 { font-size: 1.45rem; }
.source-intro, .source-list-section { padding: 17px; border: 1px solid var(--border); border-radius: 12px; background: var(--card); }
.source-intro p, .source-list p { margin-top: 6px; }
.mapping-table { width: 100%; border-collapse: collapse; text-align: left; margin-top: 14px; }
.mapping-table th, .mapping-table td { padding: 6px 8px; border-bottom: 1px solid var(--border); }
.mapping-table thead th { background: var(--soft); color: var(--ink); }
.mapping-table tbody th { font-weight: 670; }
.source-list { list-style: none; padding: 0; margin: 9px 0 0; }
.source-list li + li { margin-top: 10px; padding-top: 10px; border-top: 1px solid var(--border); }
.source-list p { color: var(--muted); font-size: .9rem; }
.external-link { overflow-wrap: anywhere; }
.lab-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 13px; align-items: start; }
.lab-card { display: grid; border: 1px solid var(--border); border-radius: 15px; overflow: hidden; background: var(--card); }
.lab-copy { padding: 15px 15px 11px; }
.lab-copy h2 { font-size: 1.35rem; margin-block: 5px; }
.lab-copy p:not(.eyebrow) { font-size: .9rem; color: var(--muted); }
.lab-canvas { margin-inline: 12px; border-radius: 9px; overflow: hidden; }
.lab-diagram { width: 100%; height: auto; }
.lab-controls { display: flex; flex-wrap: wrap; gap: 5px; margin: 10px 12px 0; }
.lab-control { min-height: 44px; padding: 6px 9px; border: 1px solid var(--strong-border); border-radius: 7px; background: var(--card); color: var(--ink); font-size: .83rem; font-weight: 660; }
.lab-control:hover { background: var(--soft); }
.lab-control[aria-pressed="true"] { background: var(--ink); color: var(--card); }
.lab-explanation { margin: 9px 12px 0; min-height: 6.2em; padding: 9px 10px; border-radius: 8px; background: var(--soft); font-size: .9rem; }
.lab-note { padding: 10px 12px 13px; font-size: .82rem; color: var(--muted); }

@media (max-width: 850px) {
  .shell { width: min(var(--shell), calc(100% - 40px)); }
  .hero-copy { padding-left: 27px; }
  .grade-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .lab-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 680px) {
  .lesson-layout { grid-template-columns: minmax(0, 1fr); gap: 14px; margin-top: 13px; }
  .lesson-rail { position: static; }
  .rail-card { padding: 9px; }
  .rail-links { display: flex; flex-wrap: wrap; }
  .rail-link { min-height: 44px; }
  .rail-foot { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; }
  .rail-foot .button { width: auto; }
  .lesson-row-end { flex-direction: column; align-items: flex-end; gap: 3px; }
  .source-grid { grid-template-columns: minmax(0, 1fr); gap: 10px; }
}
@media (max-width: 560px) {
  html { scroll-padding-top: 116px; }
  .shell { width: calc(100% - 28px); }
  #conteudo { padding-block: 17px 42px; }
  .site-header-inner { min-height: auto; gap: 0 8px; padding-top: 5px; grid-template-columns: minmax(0, 1fr) auto; }
  .brand-mark { width: 32px; height: 32px; }
  .site-nav { order: 1; grid-column: 1 / -1; gap: 4px; }
  .site-nav a { padding-inline: 9px; }
  .hero { grid-template-columns: minmax(0, 1fr); border-radius: 17px; }
  .hero-copy { padding: 22px 18px 0; }
  .hero h1 { font-size: clamp(2.6rem, 11.5vw, 3.8rem); }
  .hero-lede { margin-top: 10px; font-size: .97rem; }
  .hero-actions { margin-top: 13px; }
  .hero-artwork { padding: 0; margin-top: -2px; }
  .hero-art { width: min(95%, 310px); }
  .hero-stats { margin-bottom: 25px; }
  .hero-stats > div { flex-direction: column; gap: 1px; padding: 7px 9px; }
  .hero-stats strong { font-size: 1.25rem; }
  .hero-stats span { font-size: .75rem; line-height: 1.25; }
  .resume-strip { margin-block: 0 23px; grid-template-columns: auto 1fr; gap: 8px 10px; padding: 11px; }
  .resume-strip .button { grid-column: 2; justify-self: start; }
  .section-heading { margin-bottom: 11px; gap: 7px; }
  .section-heading > p { font-size: .86rem; }
  .grade-grid { gap: 7px; }
  .grade-card { padding: 9px; border-radius: 11px; }
  .grade-top { margin-bottom: 5px; }
  .grade-subtitle { margin-bottom: 8px; font-size: .81rem; }
  .grade-bottom { font-size: .72rem; }
  .grade-bottom .icon { width: 16px; }
  .search-panel { margin-top: 24px; padding: 12px; }
  .search-top { grid-template-columns: minmax(0, 1fr); gap: 10px; }
  .series-hero { padding: 13px; gap: 8px; }
  .series-badge, .lesson-hero-tile { width: 58px; height: 56px; border-radius: 8px; }
  .series-badge .diagram, .lesson-hero-tile .diagram { width: 46px; }
  .series-status { grid-template-columns: 1fr auto; gap: 4px 9px; margin-bottom: 20px; padding: 8px 10px; }
  .series-status progress { grid-row: 2; grid-column: 1 / -1; }
  .lesson-row { padding: 8px; gap: 7px; }
  .lesson-row .diagram-tile { width: 35px; height: 37px; }
  .lesson-row .diagram { width: 30px; }
  .lesson-row-end .row-time { display: none; }
  .status-pill { padding-inline: 5px; font-size: .7rem; }
  .lesson-row-summary { font-size: .81rem; }
  .lesson-header { grid-template-columns: minmax(0, 1fr); position: relative; padding: 12px; }
  .lesson-hero-tile { display: none; }
  .lesson-header h1 { font-size: 2.25rem; }
  .lesson-objectives { grid-template-columns: minmax(0, 1fr); gap: 7px; }
  .progress-totals > div { padding: 8px; }
  .progress-totals span { font-size: .8rem; }
  .progress-row { grid-template-columns: 1fr auto auto; gap: 4px 7px; padding: 8px; }
  .progress-row progress { grid-row: 2; grid-column: 1 / -1; }
  .progress-row-count { font-size: .73rem; }
  .lab-grid { grid-template-columns: minmax(0, 1fr); gap: 10px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition-duration: 0s !important; animation-duration: 0s !important; }
}
@media print {
  :root, :root[data-theme="dark"] {
    color-scheme: light;
    --paper: #fff;
    --card: #fff;
    --ink: #111;
    --text: #222;
    --muted: #444;
    --border: #aaa;
    --strong-border: #aaa;
    --brand: #111;
    --soft: #fff;
    --green-bg: #fff;
    --green-ink: #111;
    --orange-bg: #fff;
    --orange-ink: #111;
    --blue-bg: #fff;
    --blue-ink: #111;
    --purple-bg: #fff;
    --purple-ink: #111;
  }
  @page { margin: 13mm; }
  .site-header, .site-footer, .breadcrumbs, .skip-link, .screen-only, .notice, .quiz-meter,
  .question-actions, .answer-feedback, .answer-key summary, .answer-option input { display: none !important; }
  body { font-size: 10.5pt; }
  #conteudo { width: 100%; min-height: auto; padding: 0; }
  .lesson-header { border: 0; padding: 0; }
  .lesson-header h1 { font-size: 27pt; }
  .lesson-layout { display: block; margin-top: 12pt; }
  .lesson-content { max-width: none; }
  .lesson-content > * + * { margin-top: 12pt; }
  .lesson-objectives > section, .callout { padding: 8pt; }
  h1, h2, h3, legend { break-after: avoid; }
  p, li { orphans: 2; widows: 2; }
  .question, .answer-key li { break-inside: avoid; }
  .question { padding: 6pt; margin-top: 10pt; }
  .answer-option { grid-template-columns: auto minmax(0, 1fr); min-height: 0; padding: 3pt; background: #fff !important; color: #111 !important; border-color: #aaa !important; }
  .answer-key { break-before: page; }
  .answer-key details { border: 0; padding: 0; }
  .print-only { display: block; margin-top: 4pt; }
}