/* Public homepage only. Shared product and subject pages keep theme.css. */
.home-page { --ink: #222339; --ink-soft: #626579; --brand: #6554df; --brand-dark: #5040c7; --brand-soft: #f0edff; --line: #e8e7ef; --mint: #3c9c87; background: #fff; min-width: 0; }
.home-page [hidden] { display: none !important; }
.home-page :is(a, button, [tabindex]):focus-visible { outline: 3px solid #6554df; outline-offset: 5px; }
.home-page .container { max-width: 1220px; }
.home-page .nav { min-height: 78px; }
.home-page .brand { letter-spacing: -.05em; }
.home-page .nav-links { gap: 25px; top: 78px; }
.home-page .nav-actions .btn-ghost { display: inline-flex; }
.home-page .btn { border-radius: 10px; font-size: 14px; font-weight: 650; }
.home-page .btn-primary { box-shadow: 0 5px 15px #6554df20; }
.home-page .btn-primary:hover { background: var(--brand-dark); }
.home-page .btn-lg { gap: 18px; min-height: 52px; padding-inline: 21px; }
.home-page .section { padding: 84px 0; }
.home-page h2 { font-size: clamp(30px, 3.2vw, 43px); font-weight: 650; letter-spacing: -.055em; line-height: 1.15; }
.home-page .kicker { font-size: 11px; font-weight: 700; letter-spacing: .12em; margin-bottom: 17px; }
.home-page .section-head p { font-size: 16px; line-height: 1.7; }
.home-hero { padding: 68px 0 54px; background: radial-gradient(ellipse at 85% 42%, #e9e6ff 0, transparent 48%), linear-gradient(115deg, #faf9f6, #faf9ff); overflow: clip; }
.home-hero-grid { display: grid; grid-template-columns: .93fr 1.12fr; align-items: center; gap: 38px; }
.home-eyebrow { display: flex; align-items: center; gap: 8px; color: #696578; font-size: 11px; letter-spacing: .035em; font-weight: 600; }
.home-eyebrow > span { width: 6px; height: 6px; border-radius: 50%; background: var(--brand); box-shadow: 0 0 0 4px #6554df0c; }
.home-intro h1 { font-size: clamp(37px, 4.05vw, 54px); letter-spacing: -.06em; line-height: 1.13; margin: 23px 0 22px; font-weight: 650; text-wrap: initial; }
.home-intro h1 > span { color: var(--brand); }
.home-lead { font-size: 16px; line-height: 1.8; color: var(--ink-soft); max-width: 450px; margin-bottom: 25px; }
.home-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.home-play { font-size: 22px; line-height: 1; color: var(--brand); }
.home-reassurance { font-size: 11px; color: #6e6b7d; margin: 14px 0 25px; }
.home-student-link { font-size: 11px; color: #6e6b7d; }
.home-student-link span { color: var(--ink); margin-left: 5px; text-decoration: underline; text-underline-offset: 4px; }
.lesson-preview { min-width: 0; margin: 0; padding-top: 16px; }
.lesson-window { border: 1px solid #dedbea; border-radius: 15px; background: #fff; box-shadow: 0 24px 65px -25px #665aa84f, 0 4px 12px #22233908; overflow: hidden; transform: rotate(-1deg); }
.lesson-window-bar { display: flex; align-items: center; gap: 9px; height: 48px; padding: 0 14px; border-bottom: 1px solid #eeecf4; }
.lesson-mark { font-weight: 800; font-size: 19px; letter-spacing: -2px; color: var(--ink); padding-right: 5px; }
.lesson-mark > span { color: var(--brand); }
.lesson-window-bar > strong { font-size: 10px; font-weight: 600; }
.lesson-live { margin-left: auto; color: #338c74; background: #eaf8f1; padding: 4px 7px; border-radius: 5px; white-space: nowrap; font-size: 8px; }
.lesson-workspace { display: grid; grid-template-columns: 36px minmax(0, 1fr) 90px; gap: 10px; padding: 12px; background: #f7f7fb; }
.lesson-tools { align-self: start; display: grid; justify-items: center; gap: 5px; padding: 5px; border: 1px solid #e9e7ef; border-radius: 9px; background: #fff; }
.lesson-tools > span { display: grid; place-items: center; width: 26px; height: 28px; font-size: 16px; color: #666379; }
.lesson-tools .selected { background: var(--brand-soft); color: var(--brand); border-radius: 5px; }
.lesson-tools > i { width: 18px; border-top: 1px solid #eeecf4; margin: 3px 0; }
.lesson-tools .tool-color { width: 16px; height: 16px; background: var(--brand); border: 3px solid #ece8ff; border-radius: 50%; margin: 5px; }
.lesson-paper { position: relative; min-height: 340px; border: 1px solid #eeecf4; border-radius: 7px; background: radial-gradient(#dddae9 .8px, transparent .8px) 0 0 / 14px 14px, #fff; padding: 22px 18px; overflow: hidden; }
.paper-label { font-size: 7px; color: #9691ab; letter-spacing: .14em; font-weight: 650; }
.paper-title { font-size: 13px; margin: 6px 0 18px; font-weight: 600; }
.paper-equation { font: italic 25px Georgia, serif; color: #55469e; white-space: nowrap; }
.paper-graph { display: block; width: 100%; height: 156px; margin-top: 10px; }
.paper-answer { display: inline-block; color: #258877; font: italic 20px Georgia, serif; border-bottom: 2px solid #94d6c7; padding-bottom: 5px; }
.paper-answer span { font-size: 14px; margin: 0 6px; }
.paper-answer b { margin-left: 8px; font: 16px Inter, sans-serif; }
.paper-cursor { position: absolute; top: 208px; left: 64%; font-size: 24px; color: var(--brand); }
.paper-cursor span { font: 7px Inter, sans-serif; position: absolute; top: 23px; left: 15px; padding: 4px 6px; background: var(--brand); color: #fff; border-radius: 3px; }
.paper-note { position: absolute; right: 8px; bottom: 16px; padding: 10px; background: #fff3c7; font-size: 8px; line-height: 1.6; color: #8d793b; transform: rotate(5deg); box-shadow: 0 3px 6px #6655170a; }
.paper-note span { position: absolute; top: 5px; right: 6px; }
.lesson-side { display: grid; align-content: start; gap: 10px; }
.lesson-person { position: relative; height: 100px; overflow: hidden; border-radius: 7px; background: #e4d9f2; }
.lesson-person.student { background: #d9ede5; }
.lesson-person svg { width: 100%; height: 100%; }
.lesson-person > span { position: absolute; left: 5px; bottom: 4px; font-size: 7px; padding: 2px 4px; border-radius: 3px; background: #2725357a; color: white; }
.lesson-file { background: white; border: 1px solid #e8e6ef; border-radius: 7px; padding: 10px 7px; }
.lesson-file > span { display: inline-block; font-size: 7px; font-weight: 700; color: #c77d6c; background: #fff0ea; padding: 5px; border-radius: 4px; margin-bottom: 7px; }
.lesson-file strong, .lesson-file small { display: block; font-size: 8px; }
.lesson-file small { font-size: 6px; color: #93909f; margin-top: 3px; }
.lesson-bottom { padding: 11px 16px; display: flex; align-items: center; gap: 18px; font-size: 8px; color: #8c879d; }
.lesson-bottom > span:first-child { color: var(--brand); }
.lesson-bottom i { display: inline-block; width: 5px; height: 5px; margin-right: 4px; border-radius: 50%; background: var(--brand); }
.lesson-bottom b { font-size: 7px; padding: 2px 4px; background: #f1eff8; border-radius: 3px; }
.lesson-bottom .lesson-call { margin-left: auto; color: #d67b79; background: #ffe9e9; border-radius: 5px; padding: 3px 12px; }
.lesson-preview > figcaption { display: flex; align-items: center; flex-wrap: wrap; justify-content: center; gap: 6px; font-size: 10px; color: #777087; margin-top: 23px; }
.lesson-preview > figcaption small { flex-basis: 100%; text-align: center; font-size: 8px; color: #96909f; }
.preview-dot { width: 5px; height: 5px; border-radius: 50%; background: #44a98b; }
.home-value-strip { border-block: 1px solid var(--line); }
.home-values { display: grid; grid-template-columns: repeat(3, 1fr); padding-block: 27px; gap: 25px; }
.home-values > div { display: flex; align-items: center; gap: 15px; }
.home-values > div + div { border-left: 1px solid var(--line); padding-left: 26px; }
.value-number { color: #a39aba; font-size: 11px; font-weight: 600; }
.home-values p { margin: 0; display: grid; gap: 3px; }
.home-values strong { font-size: 13px; font-weight: 600; }
.home-values p > span { font-size: 11px; color: #726d82; }
.home-section-heading { display: flex; justify-content: space-between; gap: 50px; align-items: end; margin-bottom: 36px; }
.home-section-heading h2 { margin-bottom: 0; }
.home-section-heading h2 span { color: #868194; }
.home-section-heading > p { max-width: 330px; color: var(--ink-soft); font-size: 14px; line-height: 1.8; margin-bottom: 0; }
.feature-tabs { display: flex; gap: 7px; border-bottom: 1px solid var(--line); margin-bottom: 24px; padding-bottom: 12px; }
.feature-tabs button { display: flex; justify-content: center; align-items: center; gap: 10px; padding: 13px 20px; border: 1px solid transparent; background: transparent; color: var(--ink-soft); font-size: 13px; font-weight: 550; border-radius: 9px; cursor: pointer; }
.feature-tabs button > span { font-size: 18px; line-height: 1; }
.feature-tabs button:hover { background: #f7f5ff; }
.feature-tabs button[aria-selected="true"] { background: var(--brand-soft); color: var(--brand-dark); border-color: #e5defb; }
.feature-panel { display: grid; grid-template-columns: .85fr 1.15fr; min-height: 390px; border: 1px solid var(--line); border-radius: 18px; overflow: hidden; margin-top: 24px; }
.feature-copy { padding: 34px 36px; }
.feature-index { font-size: 9px; letter-spacing: .13em; color: #786e93; font-weight: 600; }
.feature-copy h3 { font-size: 27px; line-height: 1.22; font-weight: 600; letter-spacing: -.045em; margin: 17px 0; }
.feature-copy > p { font-size: 13px; line-height: 1.85; color: var(--ink-soft); }
.feature-copy .feature-list { gap: 11px; margin: 21px 0; }
.feature-copy .feature-list li { font-size: 12px; padding-left: 25px; }
.feature-copy .feature-list li::before { width: 16px; height: 16px; font-size: 10px; background: #f0edff; color: var(--brand); border-radius: 50%; }
.home-text-link { display: inline-flex; gap: 20px; align-items: center; color: var(--brand-dark); font-weight: 600; font-size: 12px; margin-top: 9px; }
.home-text-link:hover { text-decoration: underline; text-underline-offset: 5px; }
.feature-visual { margin: 0; background: #f5f3fb; min-width: 0; }
.lesson-detail { padding: 25px; display: flex; flex-direction: column; }
.detail-top { display: flex; justify-content: space-between; align-items: center; color: #8d879e; font-size: 9px; }
.detail-top > span:first-child { color: #544b71; font-weight: 600; }
.detail-top i { display: inline-block; width: 6px; height: 6px; background: #62b394; border-radius: 50%; margin-right: 5px; }
.detail-board { position: relative; margin-top: 20px; flex: 1; padding: 52px 35px 25px; border: 1px solid #e6e1f2; border-radius: 8px; background: radial-gradient(#ddd8ec .8px, transparent .8px) 0 0 / 16px 16px, #fff; }
.detail-sticker { position: absolute; top: 17px; left: 22px; transform: rotate(-3deg); padding: 5px 10px; background: #fff0be; color: #8d7834; font-size: 9px; }
.detail-formula { text-align: center; font: italic 32px Georgia, serif; color: #6552ae; }
.detail-board svg { display: block; width: 100%; height: 65px; margin-top: 10px; }
.detail-roots { display: flex; justify-content: space-around; gap: 20px; }
.detail-roots > span { background: #f5f2ff; border: 1px solid #e4dcfc; border-radius: 7px; padding: 8px 17px; font: italic 20px Georgia, serif; color: #6552ae; }
.detail-result { display: flex; flex-wrap: wrap; justify-content: center; gap: 5px; text-align: center; color: #868194; font-size: 11px; margin-top: 23px; }
.detail-result strong { color: #4a445e; }
.detail-result > span { flex-basis: 100%; color: #348d72; font-size: 10px; margin-top: 5px; }
.screenshot-visual { padding: 24px; display: grid; align-content: center; gap: 12px; }
.screenshot-visual img { width: 100%; height: 320px; object-fit: cover; object-position: top; border: 1px solid #e7e3ef; border-radius: 8px; background: white; }
.screenshot-visual figcaption, .home-library figcaption { font-size: 10px; color: #888297; text-align: center; }
.homework-visual, .students-visual { display: grid; align-items: center; padding: 28px 38px; background: #f1f6f3; }
.homework-example, .student-example { border: 1px solid #e5eae5; border-radius: 12px; padding: 24px; background: white; box-shadow: 0 12px 25px #253f3007; }
.example-top { display: flex; justify-content: space-between; gap: 8px; color: #799288; font-size: 8px; letter-spacing: .05em; }
.example-top > span:last-child { color: #949b96; letter-spacing: 0; }
.homework-example h4 { font-size: 20px; line-height: 1.25; font-weight: 600; letter-spacing: -.035em; margin: 17px 0 11px; }
.homework-example > p { font-size: 10px; color: #838981; line-height: 1.7; }
.homework-problems { border: 1px solid #e6eee8; background: #f8faf8; border-radius: 7px; padding: 12px; font: 18px/1.8 Georgia, serif; color: #466358; }
.homework-problems > span { color: #a6b6ac; font: 10px Inter, sans-serif; margin-right: 12px; }
.homework-meta { display: flex; justify-content: space-between; gap: 10px; font-size: 9px; padding: 14px 0; color: #8f948e; }
.homework-meta strong { color: #657067; font-weight: 500; }
.homework-feedback { display: flex; gap: 10px; border-top: 1px solid #edf0ed; padding-top: 14px; }
.homework-feedback > span { color: #62a385; background: #edf6ef; width: 26px; height: 26px; text-align: center; border-radius: 50%; }
.homework-feedback strong { color: #567c67; font-size: 10px; font-weight: 600; }
.homework-feedback p { color: #90968f; font-size: 9px; margin: 3px 0 0; }
.students-visual { background: #fbf4e9; }
.student-example { border-color: #eee5d6; }
.student-example-header { display: flex; gap: 15px; align-items: center; margin: 27px 0; }
.student-avatar { display: grid; place-items: center; width: 49px; height: 49px; background: #eee8fc; color: #8c78b2; border-radius: 14px; font-size: 24px; }
.student-example h4 { font-size: 20px; font-weight: 600; margin: 0; }
.student-example-header p { font-size: 10px; color: #92909b; margin: 3px 0 0; }
.student-note { padding: 15px 0; border-top: 1px solid #f0ece5; }
.student-note > span { display: block; font-size: 9px; color: #aaa18d; margin-bottom: 6px; }
.student-note > strong { font-size: 13px; font-weight: 500; }
.student-note > p { font-size: 11px; line-height: 1.7; color: #7b7a81; margin-bottom: 0; }
.student-tags { display: flex; gap: 7px; margin-top: 7px; }
.student-tags span { background: #f8f5ed; padding: 5px 8px; border-radius: 5px; font-size: 8px; color: #a19478; }
.home-workflow { background: #faf9f6; border-block: 1px solid #f0eee8; }
.home-steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 36px; }
.step-label { display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid #e5e1d8; padding-bottom: 15px; margin-bottom: 22px; color: #8e887a; font-size: 10px; letter-spacing: .08em; }
.step-label b { color: #c2bbae; font-size: 22px; font-weight: 400; letter-spacing: -.06em; }
.home-steps h3 { font-size: 19px; font-weight: 600; letter-spacing: -.035em; line-height: 1.3; }
.home-steps p { font-size: 13px; color: #6e6a60; line-height: 1.8; }
.step-detail { font-size: 10px; color: #81716d; margin-top: 22px; }
.step-detail > span { margin-right: 6px; }
.home-library-grid { display: grid; grid-template-columns: .8fr 1.2fr; align-items: center; gap: 55px; }
.home-library h2 { font-size: clamp(29px, 2.8vw, 37px); }
.home-library p { font-size: 14px; line-height: 1.8; color: var(--ink-soft); }
.home-library figure { margin: 0; padding: 25px 20px 15px; background: #f6f5fa; border: 1px solid #eeebf4; border-radius: 15px; }
.home-library img { width: 100%; height: auto; border-radius: 7px; box-shadow: 0 5px 20px #2223390a; }
.home-library figcaption { margin-top: 14px; }
.home-pricing { background: #faf9fd; border-block: 1px solid var(--line); }
.home-page .price-card { border-radius: 15px; padding: 30px; }
.home-page .price-card.featured { border-color: #bdb0ef; box-shadow: 0 12px 28px #6554df0b; }
.plan-label { font-size: 9px; letter-spacing: .09em; color: #9690a4; }
.featured .plan-label { color: var(--brand); }
.home-page .price-card h3 { margin-top: 17px; font-size: 23px; font-weight: 600; }
.home-page .price-card > p { font-size: 12px; color: #746d84; }
.home-page .price-card .price { font-size: 43px; font-weight: 600; margin: 27px 0; }
.home-page .price-card .price small { font-size: 12px; font-weight: 400; }
.home-page .price-card .btn { width: 100%; justify-content: space-between; }
.home-page .price-card .feature-list { margin: 24px 0 0; gap: 14px; }
.home-page .price-card li { font-size: 12px; }
.home-pricing-note { font-size: 11px; color: #746d84; text-align: center; margin: 24px 0 0; }
.home-page .home-faq { background: white; }
.home-page .faq { max-width: 820px; }
.home-page .faq summary { font-size: 15px; font-weight: 550; padding-block: 23px; }
.home-page .faq p { font-size: 14px; line-height: 1.8; }
.home-page .cta-band { padding: 0 0 74px; }
.home-page .cta-box { background: #eeebfa; color: var(--ink); padding: 53px; text-align: center; border: 1px solid #e3dcf3; border-radius: 18px; }
.home-page .cta-box::after { display: none; }
.home-page .cta-box h2 { font-size: 37px; font-weight: 600; margin-inline: auto; }
.home-page .cta-box p { color: #6d647e; font-size: 14px; margin-inline: auto; }
.home-page .cta-actions { justify-content: center; }
.home-page .cta-box .btn-secondary { background: white; border-color: #d9d1ea; color: var(--ink); }
.home-page .site-footer { background: #fcfbfe; padding-top: 45px; }
.home-page .footer-about, .home-page .footer-links a { font-size: 12px; }
.home-page .footer-links h3 { font-size: 10px; color: #9a93a8; }
.home-page .footer-bottom { font-size: 10px; margin-top: 30px; }
.home-page .cookie-banner { width: min(650px, calc(100% - 30px)); padding: 12px 15px; border-radius: 12px; }
.home-page .cookie-row p { font-size: 11px; }
@media (max-width: 1100px) {
  .home-hero-grid { gap: 24px; grid-template-columns: .94fr 1.06fr; }
  .home-intro h1 { font-size: 42px; }
  .lesson-workspace { grid-template-columns: 30px minmax(0, 1fr) 70px; gap: 7px; padding: 9px; }
  .lesson-tools { padding: 2px; }
  .lesson-paper { padding: 20px 12px; }
  .lesson-person { height: 84px; }
  .paper-equation { font-size: 21px; }
  .paper-note { bottom: 10px; }
  .feature-copy { padding: 28px; }
  .homework-visual, .students-visual { padding: 25px; }
}
@media (max-width: 850px) {
  .home-hero { padding-top: 43px; }
  .home-hero-grid { grid-template-columns: 1fr; gap: 27px; }
  .home-intro { max-width: 570px; }
  .home-intro h1 { font-size: 52px; }
  .home-lead { max-width: 520px; }
  .lesson-preview { width: 100%; max-width: 650px; margin-inline: auto; }
  .lesson-workspace { grid-template-columns: 36px minmax(0, 1fr) 100px; padding: 14px; gap: 12px; }
  .lesson-paper { padding: 22px; }
  .lesson-person { height: 100px; }
  .paper-equation { font-size: 28px; }
  .paper-graph { height: 160px; }
  .home-values { gap: 15px; }
  .home-values > div { gap: 8px; }
  .home-values > div + div { padding-left: 15px; }
  .home-values strong { font-size: 11px; }
  .home-values p > span { font-size: 9px; }
  .home-section-heading { gap: 30px; }
  .home-section-heading > p { max-width: 260px; font-size: 12px; }
  .feature-tabs button { flex: 1; gap: 7px; padding: 13px 8px; font-size: 11px; }
  .feature-panel { grid-template-columns: 1fr 1fr; }
  .feature-copy { padding: 25px; }
  .feature-copy h3 { font-size: 23px; }
  .lesson-detail { padding: 18px; }
  .detail-board { padding: 60px 10px 25px; }
  .detail-formula { font-size: 25px; }
  .detail-roots { gap: 10px; }
  .detail-roots > span { padding: 7px 10px; font-size: 17px; }
  .homework-visual, .students-visual { padding: 18px; }
  .homework-example, .student-example { padding: 18px; }
  .home-steps { gap: 25px; }
  .home-steps h3 { font-size: 17px; }
  .home-library-grid { grid-template-columns: 1fr; gap: 30px; }
}
@media (max-width: 600px) {
  .home-page .container { width: calc(100% - 36px); }
  .home-page .nav { min-height: 68px; gap: 14px; }
  .home-page .nav-links { top: 68px; }
  .home-page .section { padding: 56px 0; }
  .home-page .nav-actions { display: flex; }
  .home-page .nav .btn-ghost { display: inline-flex; }
  .home-hero { padding: 37px 0 30px; }
  .home-eyebrow { font-size: 10px; }
  .home-intro h1 { font-size: clamp(32px, 8.8vw, 48px); margin-top: 21px; }
  .home-lead { font-size: 14px; line-height: 1.75; margin-bottom: 23px; }
  .home-actions { gap: 8px; }
  .home-actions .btn-lg { min-height: 49px; font-size: 12px; padding-inline: 14px; gap: 9px; }
  .home-reassurance { font-size: 10px; margin-bottom: 18px; }
  .home-student-link { font-size: 10px; display: flex; flex-wrap: wrap; gap: 5px; }
  .home-student-link span { margin: 0; }
  .lesson-preview { padding-top: 0; }
  .lesson-window { transform: none; border-radius: 10px; }
  .lesson-window-bar { height: 39px; padding-inline: 9px; gap: 5px; }
  .lesson-window-bar > strong { font-size: 7px; }
  .lesson-mark { font-size: 16px; }
  .lesson-live { font-size: 6px; padding: 3px 4px; }
  .lesson-workspace { grid-template-columns: 24px minmax(0, 1fr) 58px; padding: 7px; gap: 5px; }
  .lesson-tools > span { width: 20px; height: 24px; font-size: 14px; }
  .lesson-tools .tool-color { width: 14px; height: 14px; margin: 3px; }
  .lesson-paper { min-height: 273px; padding: 15px 10px; }
  .paper-label { font-size: 6px; }
  .paper-title { font-size: 10px; margin-bottom: 13px; }
  .paper-equation { font-size: 19px; }
  .paper-graph { height: 115px; margin-top: 2px; }
  .paper-answer { font-size: 15px; }
  .paper-answer span { margin-inline: 3px; font-size: 12px; }
  .paper-answer b { margin-left: 3px; font-size: 12px; }
  .paper-note { bottom: 9px; right: 9px; font-size: 6px; padding: 5px 10px 5px 6px; }
  .paper-cursor { top: 167px; font-size: 19px; }
  .paper-cursor span { font-size: 6px; top: 18px; left: 10px; }
  .lesson-person { height: 74px; }
  .lesson-person > span { font-size: 5px; left: 2px; bottom: 3px; padding: 2px; }
  .lesson-file { padding: 7px 4px; }
  .lesson-file strong { font-size: 7px; }
  .lesson-file small { font-size: 5px; }
  .lesson-bottom { padding: 9px; gap: 13px; font-size: 7px; }
  .lesson-preview > figcaption { font-size: 8px; margin-top: 15px; }
  .lesson-preview > figcaption small { font-size: 7px; }
  .home-values { grid-template-columns: 1fr; gap: 17px; padding-block: 24px; }
  .home-values > div, .home-values > div + div { border: 0; padding: 0; gap: 16px; }
  .home-values strong { font-size: 12px; }
  .home-values p > span { font-size: 10px; }
  .home-section-heading { display: block; margin-bottom: 25px; }
  .home-section-heading > p { margin-top: 20px; max-width: none; font-size: 13px; }
  .feature-tabs { display: grid; grid-template-columns: 1fr 1fr; gap: 7px; }
  .feature-tabs button { justify-content: start; padding: 12px 9px; font-size: 11px; min-height: 44px; }
  .feature-panel { grid-template-columns: 1fr; }
  .feature-copy { padding: 26px; }
  .feature-copy h3 { font-size: 27px; }
  .feature-copy p { font-size: 13px; }
  .feature-visual { min-height: 320px; }
  .lesson-detail { padding: 18px; }
  .detail-board { padding: 60px 15px 25px; }
  .detail-formula { font-size: 28px; }
  .screenshot-visual { padding: 16px; }
  .screenshot-visual img { height: auto; max-height: 380px; }
  .homework-visual, .students-visual { padding: 22px; }
  .home-steps { grid-template-columns: 1fr; gap: 32px; }
  .step-label { margin-bottom: 15px; padding-bottom: 10px; }
  .home-steps h3 { font-size: 20px; margin-bottom: 10px; }
  .step-detail { margin-top: 16px; }
  .home-page .section-head { margin-bottom: 30px; }
  .home-page .section-head p { font-size: 13px; }
  .home-library figure { padding: 18px 10px 12px; }
  .home-page .pricing-grid { gap: 16px; }
  .home-page .price-card { padding: 26px; }
  .home-page .price-card li { font-size: 12px; }
  .home-pricing-note { font-size: 10px; }
  .home-page .faq summary { font-size: 14px; }
  .home-page .faq p { font-size: 13px; }
  .home-page .cta-band { padding-bottom: 50px; }
  .home-page .cta-box { padding: 35px 22px; }
  .home-page .cta-box h2 { font-size: 29px; }
  .home-page .cta-box p { font-size: 13px; }
  .home-page .cookie-row { gap: 10px; }
}
@media (max-width: 380px) {
  .home-actions .btn { width: 100%; justify-content: center; }
  .lesson-workspace { grid-template-columns: 24px minmax(0, 1fr) 50px; }
  .paper-equation { font-size: 16px; }
  .paper-title { font-size: 9px; }
  .lesson-window-bar > strong { font-size: 6px; }
  .detail-formula { font-size: 23px; }
  .detail-roots > span { font-size: 15px; padding-inline: 9px; }
  .homework-visual, .students-visual { padding: 15px; }
  .student-example h4 { font-size: 17px; }
}