/* MathNivo's shared static-page layout. */
:root {
  color-scheme: light;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: #12213f;
  background: #f6f8fc;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}
* { box-sizing: border-box; }
body { margin: 0; line-height: 1.65; background: #f6f8fc; }
a { color: #2445b2; text-underline-offset: 3px; }
a:focus-visible { outline: 3px solid #168f82; outline-offset: 4px; border-radius: 4px; }
.shell { width: min(calc(100% - 32px), 1160px); margin-inline: auto; }
.skip-link { position: fixed; z-index: 10; top: 12px; left: 12px; transform: translateY(-160%); padding: 10px 14px; border-radius: 8px; background: #12213f; color: white; }
.skip-link:focus { transform: translateY(0); }
.site-header { background: #fff; border-bottom: 1px solid #dde4f0; }
.header-inner { min-height: 72px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.wordmark { color: #12213f; font-size: 1.38rem; font-weight: 850; letter-spacing: -.045em; text-decoration: none; }
.header-nav { display: flex; flex-wrap: wrap; align-items: center; gap: clamp(12px, 2.4vw, 28px); font-size: .94rem; }
.header-nav a { color: #52617b; text-decoration: none; }
.header-nav a:hover { color: #12213f; }
.page-main { min-height: 62vh; padding-block: clamp(36px, 7vw, 76px); }
.content-card { max-width: 820px; margin-inline: auto; padding: clamp(24px, 6vw, 52px); border: 1px solid #dde4f0; border-radius: 20px; background: #fff; box-shadow: 0 18px 50px rgba(23, 33, 58, .06); }
.eyebrow { margin: 0 0 12px; color: #3157d5; font-size: .78rem; font-weight: 800; letter-spacing: .13em; text-transform: uppercase; }
h1 { margin: 0 0 16px; font-size: clamp(2.1rem, 7vw, 3.4rem); line-height: 1.08; letter-spacing: -.05em; }
h2 { margin: 32px 0 10px; font-size: 1.35rem; line-height: 1.3; }
p, li { color: #3f4c65; }
.updated { margin: 0 0 30px; color: #68758c; font-size: .95rem; }
.course-links { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.course-links a { display: inline-flex; padding: 10px 14px; border: 1px solid #dde4f0; border-radius: 999px; background: #fff; font-weight: 650; text-decoration: none; }
.course-links a:hover { border-color: #3157d5; background: #eaf0ff; }
.site-footer { padding-block: 24px; border-top: 1px solid #dde4f0; background: #fff; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 20px; color: #52617b; font-size: .94rem; }
.footer-links { display: flex; flex-wrap: wrap; gap: 18px; }
.footer-links a { color: #52617b; }
.footer-links a:hover { color: #12213f; }
@media (max-width: 760px) {
  .header-inner { align-items: flex-start; flex-direction: column; gap: 8px; padding-block: 14px; }
  .header-nav { gap: 8px 16px; font-size: .9rem; }
  .footer-inner { align-items: flex-start; flex-direction: column; }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; animation-duration: .01ms !important; } }
/* Course landing pages */
.nav-group { position: relative; }
.nav-group summary { cursor: pointer; list-style: none; }
.nav-group summary::-webkit-details-marker { display: none; }
.nav-group summary::after { content: "⌄"; margin-left: 5px; color: #7b879e; }
.nav-menu { position: absolute; z-index: 20; top: calc(100% + 10px); left: -12px; display: grid; min-width: 158px; padding: 7px; border: 1px solid #dde4f0; border-radius: 12px; background: #fff; box-shadow: 0 12px 32px rgba(23,33,58,.13); }
.nav-menu a { padding: 8px 10px; border-radius: 7px; }
.nav-menu a:hover { background: #eaf0ff; color: #12213f; }
.course-hero { padding: clamp(36px,7vw,78px) 0 clamp(44px,7vw,82px); background: #fff; border-bottom: 1px solid #e4e9f2; }
.course-hero-inner { max-width: 1030px; }
.breadcrumb { display: flex; gap: 10px; align-items: center; margin-bottom: 34px; color: #75819a; font-size: .9rem; }
.breadcrumb a { color: #52617b; }
.course-hero-grid { display: grid; grid-template-columns: minmax(0,1.25fr) minmax(250px,.75fr); align-items: center; gap: clamp(28px,6vw,74px); }
.course-hero .eyebrow { display: flex; flex-wrap: wrap; gap: 7px; align-items: center; }
.course-hero h1 { max-width: 700px; margin-bottom: 18px; }
.course-intro { max-width: 650px; margin: 0; color: #52617b; font-size: clamp(1.08rem,2vw,1.24rem); }
.course-hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 18px; margin-top: 26px; }
.app-status { display: inline-flex; align-items: center; padding: 9px 14px; border-radius: 999px; background: #eaf0ff; color: #2445b2; font-weight: 750; font-size: .9rem; }
.text-cta { font-weight: 700; text-decoration-thickness: 1px; }
.course-note { display: flex; align-items: flex-start; gap: 14px; padding: 22px; border: 1px solid #dde4f0; border-radius: 18px; background: #f8faff; }
.note-mark { display: grid; flex: 0 0 auto; place-items: center; width: 38px; height: 38px; border-radius: 11px; background: #3157d5; color: #fff; font-size: 1.1rem; font-weight: 850; }
.course-note p { margin: 0; color: #52617b; font-size: .96rem; }
.course-note strong { color: #12213f; }
.section { padding: clamp(50px,8vw,88px) 0; }
.section-heading { max-width: 760px; margin-bottom: 34px; }
.section-heading .eyebrow { margin-bottom: 10px; }
.section-heading h2 { margin-top: 0; }
.section-heading p:last-child { margin-bottom: 0; color: #52617b; }
.curriculum-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 16px; }
.topic-card { min-width: 0; padding: 22px; border: 1px solid #dde4f0; border-radius: 18px; background: #fff; box-shadow: 0 10px 28px rgba(23,33,58,.045); }
.topic-topline { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 20px; }
.topic-index { display: grid; place-items: center; width: 31px; height: 31px; border-radius: 9px; background: #eaf0ff; color: #3157d5; font-size: .82rem; font-weight: 800; }
.topic-count { color: #62718c; font-size: .78rem; font-weight: 700; white-space: nowrap; }
.topic-card h3 { margin: 0 0 8px; color: #12213f; font-size: 1.12rem; line-height: 1.3; }
.topic-card p { margin: 0; color: #52617b; font-size: .95rem; }
.topic-footnote { margin: 22px 0 0; color: #64718a; font-size: .88rem; }
.section-soft { background: #edf2fb; }
.next-steps { display: grid; grid-template-columns: minmax(0,1.4fr) minmax(230px,.6fr); gap: 44px; align-items: center; }
.next-steps h2 { margin: 0 0 12px; }
.next-steps p { max-width: 660px; }
.next-links { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
.next-links a { display: inline-flex; gap: 8px; padding: 9px 12px; border: 1px solid #d8e0ed; border-radius: 999px; background: white; font-size: .9rem; font-weight: 650; text-decoration: none; }
.next-links a:hover { border-color: #3157d5; }
.next-status { display: grid; gap: 6px; padding: 20px; border: 1px solid #d8e0ed; border-radius: 15px; background: white; }
.next-status span { color: #64718a; font-size: .9rem; }
.error-card { margin-block: 36px; }
.error-card h1 { font-size: clamp(2.3rem,6vw,3.5rem); }
.button-link { display: inline-flex; gap: 10px; align-items: center; padding: 12px 17px; border-radius: 10px; background: #3157d5; color: #fff; font-weight: 750; text-decoration: none; }
.button-link:hover { background: #2445b2; color: #fff; }
@media (max-width: 900px) { .curriculum-grid { grid-template-columns: repeat(2,minmax(0,1fr)); } .course-hero-grid { grid-template-columns: 1fr; } .course-note { max-width: 600px; } }
@media (max-width: 760px) { .header-inner { gap: 12px; } .header-nav { flex-wrap: wrap; gap: 8px 16px; } .next-steps { grid-template-columns: 1fr; gap: 26px; } }
@media (max-width: 520px) { .curriculum-grid { grid-template-columns: 1fr; } .topic-card { padding: 20px; } .breadcrumb { margin-bottom: 25px; } .course-hero-actions { align-items: flex-start; flex-direction: column; gap: 14px; } .footer-links { justify-content: flex-start; } }
.published-guide-links { margin-top: 28px; padding: 24px; border: 1px solid #dde4f0; border-radius: 16px; background: #fff; }
.published-guide-links h3 { margin: 0 0 6px; color: #12213f; }
.published-guide-links p { margin: 0 0 14px; color: #52617b; }