:root {
  color-scheme: light;
  --bg: #f7f8fa;
  --surface: #ffffff;
  --surface-muted: #f0f6ff;
  --text: #172033;
  --muted: #5d6b82;
  --border: #dbe3ef;
  --primary: #0b6ffb;
  --primary-hover: #075ed8;
  --shadow: 0 20px 50px rgba(23, 32, 51, 0.08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--text); font-family: "Segoe UI", system-ui, sans-serif; line-height: 1.6; }
a { color: inherit; }
.container { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }
.skip-link { position: fixed; left: 12px; top: -60px; z-index: 20; background: var(--text); color: white; padding: 8px 12px; border-radius: 8px; }
.skip-link:focus { top: 12px; }
.site-header { position: sticky; top: 0; z-index: 10; background: rgba(247, 248, 250, .94); border-bottom: 1px solid rgba(219, 227, 239, .9); backdrop-filter: blur(12px); }
.nav { min-height: 68px; display: flex; align-items: center; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 9px; text-decoration: none; font-weight: 760; letter-spacing: -.02em; }
.brand img { width: 29px; height: 29px; }
.nav-links { margin-left: auto; display: flex; gap: 20px; align-items: center; }
.nav-links a { color: var(--muted); font-size: .93rem; text-decoration: none; }
.nav-links a:hover { color: var(--primary); }
.nav-toggle { display: none; margin-left: auto; background: var(--surface); border: 1px solid var(--border); border-radius: 8px; color: var(--text); padding: 7px 10px; }
.hero { padding: 88px 0 74px; background: linear-gradient(145deg, #fff 0%, #f4f8ff 100%); }
.hero-grid, .split, .download-grid, .privacy-card { display: grid; grid-template-columns: 1.1fr .9fr; gap: 54px; align-items: center; }
.eyebrow { color: var(--primary); font-size: .8rem; font-weight: 750; letter-spacing: .08em; text-transform: uppercase; margin: 0 0 10px; }
h1, h2, h3 { line-height: 1.18; letter-spacing: -.03em; }
h1 { max-width: 650px; font-size: clamp(2.5rem, 6vw, 4.8rem); margin: 0 0 20px; }
h2 { font-size: clamp(1.8rem, 3vw, 2.8rem); margin: 0 0 14px; }
h3 { font-size: 1.08rem; margin: 0 0 7px; }
.lead { max-width: 620px; color: var(--muted); font-size: 1.13rem; }
.hero-actions, .download-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 27px; }
.button { display: inline-flex; justify-content: center; align-items: center; min-height: 44px; padding: 10px 17px; border-radius: 10px; font-weight: 700; text-decoration: none; transition: transform .16s ease, background .16s ease; }
.button:hover { transform: translateY(-1px); }
.button-primary { background: var(--primary); color: white; }
.button-primary:hover { background: var(--primary-hover); }
.button-secondary { background: var(--surface); border: 1px solid var(--border); color: var(--text); }
.quiet { color: var(--muted); font-size: .9rem; margin-top: 15px; }
.hero-card { display: grid; gap: 18px; padding: 28px; border: 1px solid var(--border); border-radius: 18px; background: var(--surface); box-shadow: var(--shadow); }
.hero-card-mark { width: 44px; height: 44px; display: grid; place-items: center; border-radius: 12px; background: var(--primary); color: white; font-weight: 800; }
.hero-card strong, .hero-card span { display: block; }
.hero-card span { color: var(--muted); font-size: .93rem; }
.section { padding: 82px 0; }
.section-muted { background: var(--surface-muted); border-block: 1px solid #e1ebf8; }
.section-heading { max-width: 690px; margin-bottom: 32px; }
.section-heading > p:last-child { color: var(--muted); margin: 0; }
.demo-frame { overflow: hidden; border: 1px solid var(--border); border-radius: 18px; background: var(--surface); box-shadow: var(--shadow); }
video { width: 100%; display: block; background: #e9eff8; }
.demo-fallback { text-align: center; color: var(--muted); }
.demo-fallback img { width: 100%; display: block; }
.demo-fallback p { margin: 0; padding: 13px 20px; }
.demo-frame.has-video .demo-fallback { display: none; }
.flow-list { display: grid; grid-template-columns: repeat(5, 1fr); gap: 14px; padding: 0; list-style: none; }
.flow-list li { position: relative; min-height: 160px; padding: 20px; border: 1px solid var(--border); border-radius: 14px; background: var(--surface); }
.flow-list span { display: grid; place-items: center; width: 28px; height: 28px; margin-bottom: 18px; border-radius: 50%; background: var(--primary); color: white; font-size: .85rem; font-weight: 700; }
.flow-list strong, .flow-list small { display: block; }
.flow-list small { margin-top: 8px; color: var(--muted); }
.feature-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.feature-grid article { padding: 22px; border: 1px solid var(--border); border-radius: 14px; background: var(--surface); }
.feature-grid p { margin: 0; color: var(--muted); }
.check-list { display: grid; gap: 12px; padding: 0; margin: 0; list-style: none; }
.check-list li { padding-left: 28px; position: relative; }
.check-list li::before { content: "✓"; position: absolute; left: 0; color: var(--primary); font-weight: 800; }
.privacy-card { padding: 34px; border: 1px solid var(--border); border-radius: 18px; background: var(--surface); }
.coursewave-card { margin-top: 34px; padding: 28px; border: 1px solid var(--border); border-radius: 18px; background: var(--surface); }
.coursewave-card p { color: var(--muted); margin-bottom: 0; }
.status-notice { margin: 20px 0 0; padding: 14px 16px; border-left: 4px solid var(--primary); border-radius: 8px; background: var(--surface); color: var(--muted); }
.download-grid { align-items: start; }
.faq { max-width: 820px; }
details { padding: 16px 0; border-bottom: 1px solid var(--border); }
summary { cursor: pointer; font-weight: 700; }
details p { color: var(--muted); margin: 10px 0 0; }
.open-source { text-align: center; background: #10233f; color: white; }
.open-source .eyebrow { color: #8fc0ff; }
.open-source h2 { max-width: 700px; margin-inline: auto; }
.open-source .button-secondary { border-color: #4a668b; background: transparent; color: white; }
footer { padding: 28px 0; background: #0e1d33; color: #cbd5e1; font-size: .9rem; }
.footer-grid { display: flex; justify-content: space-between; align-items: center; gap: 18px; }
.footer-grid p { margin: 0; }
button:focus-visible, a:focus-visible, summary:focus-visible { outline: 3px solid #f3b53d; outline-offset: 3px; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } *, *::before, *::after { transition: none !important; } }
@media (max-width: 860px) { .hero-grid, .split, .download-grid, .privacy-card { grid-template-columns: 1fr; gap: 30px; } .flow-list { grid-template-columns: 1fr; } .feature-grid { grid-template-columns: repeat(2, 1fr); } .hero { padding-top: 62px; } }
@media (max-width: 680px) { .container { width: min(100% - 28px, 1120px); } .nav { min-height: 60px; flex-wrap: wrap; } .nav-toggle { display: block; } .nav-links { display: none; width: 100%; margin: 0 0 14px; flex-direction: column; align-items: flex-start; } .nav-links.is-open { display: flex; } .feature-grid { grid-template-columns: 1fr; } .section { padding: 60px 0; } .footer-grid { align-items: flex-start; flex-direction: column; } }