/* Open theory, framed examples and mistake cards, collapsible FAQ. */
.oz9-page .oz-main { max-width: 1080px; padding-inline: 28px; }
.oz9-page .oz-h1 { max-width: 24ch; font-size: clamp(28px, 3.5vw, 40px); line-height: 1.3; }
.oz9-page .oz-lede { max-width: none; font-size: 18px; line-height: 1.8; }
.oz9-page .oz-section { padding-bottom: 0; }
.oz9-theory { margin: 24px 0 0; font-size: 17px; line-height: 1.85; }
.oz9-theory p { margin: 0 0 18px; }
.oz9-page .oz9-eyebrow { margin: 0 0 12px; color: var(--oz-violet-soft); font: 600 12px/1.5 var(--oz-font-body); letter-spacing: .09em; text-transform: uppercase; }
.oz9-contents { padding: 24px 0 26px; border-block: 1px solid var(--oz-border-slate); }
.oz9-page .oz9-contents .oz9-eyebrow { color: var(--oz-text-primary); }
.oz9-contents ol { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); grid-template-rows: repeat(3, auto); grid-auto-flow: column; gap: 4px 32px; margin: 8px 0 0; padding-left: 22px; }
.oz9-contents li { padding-left: 4px; color: var(--oz-text-secondary); }
.oz9-contents a { display: inline-block; padding: 5px 0; font-size: 15px; line-height: 1.6; }
.oz9-page .oz9-contents a:hover, .oz9-practice:hover { text-decoration: underline; text-underline-offset: 4px; }
.oz9-page a:focus-visible { outline: 2px solid var(--oz-violet-soft); outline-offset: 4px; border-radius: 2px; }
.oz9-section { padding: 42px 0 4px; margin-top: 34px; border-top: 1px solid var(--oz-border-slate); }
.oz9-contents + .oz9-section { margin-top: 0; border-top: 0; }
.oz9-page :is(.oz9-section, .oz9-theory h3, #oshibki, #faq) { scroll-margin-top: 110px; }
.oz9-section h2, .oz9-page .oz-layout-main > section > .oz-h2 { margin: 0 0 22px; font: 700 clamp(24px, 2.6vw, 29px)/1.4 var(--oz-font-display); color: var(--oz-text-primary); letter-spacing: -.025em; text-wrap: pretty; }
.oz9-section h3 { margin: 30px 0 14px; font-family: var(--oz-font-display); font-size: 20px; font-weight: 700; line-height: 1.5; color: var(--oz-text-primary); }
.oz9-theory strong { color: var(--oz-text-primary); font-weight: 700; }
.oz9-section > ol, .oz9-section > ul { margin: 16px 0 24px; padding-left: 25px; }
.oz9-section > ol > li, .oz9-section > ul > li { margin: 10px 0; padding-left: 6px; }
.oz9-section > ol > li::marker { color: var(--oz-violet-soft); font-weight: 700; }
.oz9-theory .oz9-formula { margin: 20px 0 24px; padding: 6px 0 10px; color: var(--oz-text-primary); font-size: 19px; }
.oz9-formula, .oz9-math { max-width: 100%; overflow-x: auto; overflow-y: hidden; }
.oz9-theory .oz9-takeaway { margin-block: 24px; }
.oz9-practice { display: inline-block; padding: 8px 0; font-weight: 600; font-size: 15px; line-height: 1.6; }

.oz9-example { margin: 28px 0; padding: 26px 30px; border: 1px solid rgba(182, 156, 255, .3); border-radius: 14px; background: rgba(182, 156, 255, .035); }
.oz9-example h4 { margin: 0 0 18px; font-size: 19px; font-weight: 700; line-height: 1.5; color: var(--oz-text-primary); }
.oz9-example-condition { padding-bottom: 14px; border-bottom: 1px solid var(--oz-border-subtle); }
.oz9-example-condition p { margin-bottom: 10px; }
.oz9-example-condition .oz9-math { font-size: 21px; }
.oz9-worked-steps { margin: 22px 0; padding-left: 24px; }
.oz9-worked-steps li { margin: 0 0 20px; padding-left: 8px; }
.oz9-worked-steps li::marker { color: var(--oz-violet-soft); font-weight: 700; }
.oz9-worked-steps p { margin-bottom: 8px; }
.oz9-step-title { font-weight: 700; color: var(--oz-text-primary); }
.oz9-theory .oz9-math { padding: 5px 0 9px; }
.oz9-theory .oz9-check { font-size: 15px; line-height: 1.8; }
.oz9-theory .oz9-example-answer { margin: 20px 0 0; padding-top: 16px; border-top: 1px solid var(--oz-border-subtle); font-size: 18px; }
.oz9-example-answer strong { color: #c9bbff; }
.oz9-alternative { margin-top: 20px; }
.oz9-alternative h4 { margin-bottom: 10px; font-size: 16px; }
.oz9-alternative p { margin-bottom: 0; font-size: 15px; }
.oz9-theory .katex { font-size: 1.08em; }
.oz9-inline-condition { white-space: nowrap; font: 1.08em var(--oz-font-math); }

/* Mistakes use cards; FAQ uses the shared question/answer accordion. */
.oz9-page .oz-section-divider { margin-top: 34px; padding-top: 42px; border-top-color: var(--oz-border-slate); }
.oz9-page .oz-h2-lead { max-width: none; font-size: 17px; line-height: 1.8; }
.oz9-mistakes { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; margin: 0; padding: 0; list-style: none; }
.oz9-mistakes li { padding: 24px; border: 1px solid var(--oz-border-slate); border-radius: 14px; background: var(--oz-elevated); }
.oz9-mistakes h3 { margin: 0 0 12px; font-size: 18px; line-height: 1.6; color: var(--oz-text-primary); }
.oz9-mistakes p { margin: 0; font-size: 16px; line-height: 1.8; }
.oz9-page .oz-faq-head:focus-visible { outline: 2px solid var(--oz-violet-soft); outline-offset: 3px; }

/* The practice CTA continues the article: same divider, heading and card frame as .oz9-example. */
.oz9-practice-intro { margin-top: 34px; padding-top: 42px; border-top: 1px solid var(--oz-border-slate); }
.oz9-practice-intro h2 { margin: 0 0 14px; font: 700 clamp(24px, 2.6vw, 29px)/1.4 var(--oz-font-display); color: var(--oz-text-primary); letter-spacing: -.025em; text-wrap: pretty; }
.oz9-practice-intro p { margin: 0; font-size: 17px; line-height: 1.8; }
.oz9-page .oz-cta-panel { margin-top: 24px; padding: 28px 30px; border: 1px solid rgba(182, 156, 255, .3); border-radius: 14px; background: rgba(182, 156, 255, .035); box-shadow: none; }
.oz9-page .oz-cta-panel::before { content: none; }
.oz9-page .oz-cta-inner { gap: 28px; }
.oz9-page .oz-cta-inner p { margin-bottom: 20px; font-size: 16px; line-height: 1.75; }
.oz9-page .oz-cta-text p, .oz9-page .oz-cta-micro { max-width: none; }
.oz9-page .oz-cta-row { align-items: stretch; gap: 12px; }
.oz9-page .oz-cta-btn { padding: 15px 18px; font-size: 16px; letter-spacing: .2px; }
.oz9-page .oz-cta-micro { font-size: 14px; line-height: 1.6; }
.oz9-page .oz-cta-panel .hero2-board { box-shadow: none; }
/* The 650px demo fits beside the copy only once the article reaches its full 1024px column. */
@media (min-width: 1080px) {
    .oz9-page .oz-cta-inner { grid-template-columns: minmax(0, 1fr) 650px; }
}

@media (max-width: 600px) {
    .oz9-page .oz-main { padding-inline: 20px; }
    .oz9-page .oz-lede { font-size: 16px; }
    .oz9-theory, .oz9-mistakes p { font-size: 16px; line-height: 1.85; }
    .oz9-mistakes { grid-template-columns: 1fr; }
    .oz9-mistakes li { padding: 20px; }
    .oz9-contents ol { grid-template-columns: 1fr; grid-template-rows: none; grid-auto-flow: row; gap: 2px; }
    .oz9-contents a { padding-block: 7px; }
    .oz9-section, .oz9-page .oz-section-divider, .oz9-practice-intro { padding-top: 30px; margin-top: 26px; }
    .oz9-page .oz-cta-panel { padding: 20px 18px; border-radius: 12px; }
    .oz9-section h3 { font-size: 18px; }
    .oz9-example { padding: 20px 18px; margin-block: 24px; border-radius: 12px; }
    .oz9-example h4 { font-size: 18px; }
    .oz9-example-condition .oz9-math { font-size: 19px; }
    .oz9-worked-steps { padding-left: 20px; }
    .oz9-worked-steps li { padding-left: 4px; }
    .oz9-theory .oz9-formula { font-size: 17px; }
}