/* Shared shell for Quiveld and its static section pages. */
:root { color-scheme: light; font-family: Arial, "PingFang SC", "Microsoft YaHei", sans-serif; color: #242424; background: #fafafa; -webkit-font-smoothing: antialiased; }
*, *::before, *::after { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; min-height: 100svh; display: flex; flex-direction: column; }
a { color: inherit; }
a:focus-visible { outline: 2px solid #555; outline-offset: 5px; }
.skip-link { position: absolute; top: 8px; left: 16px; padding: 12px; background: #fff; z-index: 10; transform: translateY(-160%); }
.skip-link:focus { transform: translateY(0); }
.site-header { border-bottom: 1px solid #eaeaea; }
.nav { max-width: 1120px; margin: auto; min-height: 64px; padding: 0 28px; display: flex; justify-content: space-between; align-items: center; gap: 24px; }
.brand { color: #292929; text-decoration: none; font-size: 17px; font-weight: 600; letter-spacing: -.5px; }
.nav-link { color: #575757; text-decoration: none; font-size: 14px; padding: 16px 2px; }
.nav-link:hover, .nav-link[aria-current="page"] { color: #1d1d1d; text-decoration: underline; text-underline-offset: 6px; }
main { flex: 1; display: grid; place-items: center; padding: 72px 24px; }
.hero { text-align: center; transform: translateY(-3%); }
h1 { margin: 0 0 20px; font-size: clamp(48px, 8vw, 70px); font-weight: 600; line-height: 1.1; letter-spacing: -.055em; }
.subtitle { margin: 0; color: #777; font-size: 16px; line-height: 1.75; }
.subtitle-zh { color: #858585; font-size: 14px; letter-spacing: .02em; }
footer { flex: none; padding: 24px 16px 29px; text-align: center; color: #969696; font-size: 12px; letter-spacing: .02em; }
.directory { display: block; width: min(100%, 768px); margin-inline: auto; text-align: left; place-items: normal; }
.directory h1 { font-size: clamp(36px, 6vw, 48px); letter-spacing: -.04em; }
.eyebrow { margin: 0 0 16px; font-size: 12px; color: #777; letter-spacing: .12em; text-transform: uppercase; }
.exercise-list { list-style: none; padding: 0; margin: 40px 0 0; border-top: 1px solid #e4e4e4; }
.exercise-list li { border-bottom: 1px solid #e4e4e4; }
.exercise-list a { display: flex; align-items: center; gap: 24px; min-height: 72px; padding: 18px 12px; text-decoration: none; }
.exercise-list a:hover { background: #f0f0f0; }
.exercise-number { color: #777; font-size: 12px; font-variant-numeric: tabular-nums; }
.exercise-name { flex: 1; min-width: 0; font-size: 16px; }
.exercise-arrow { color: #777; }
.exercise-note { display: block; color: #777; font-size: 13px; line-height: 1.75; margin-top: 6px; }
@media (max-width: 600px) { .nav { min-height: 58px; padding: 0 20px; } main { padding: 60px 20px; } .hero h1 { font-size: clamp(45px, 13vw, 60px); } .subtitle { font-size: 14px; } .subtitle-zh { font-size: 13px; } .exercise-list a { gap: 16px; } }

.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-link[aria-current="true"] { color: #1d1d1d; text-decoration: underline; text-underline-offset: 6px; }
.breadcrumbs { margin-bottom: 28px; font-size: 12px; line-height: 1.8; color: #777; }
.breadcrumbs ol { display: flex; flex-wrap: wrap; gap: 4px 8px; list-style: none; padding: 0; margin: 0; }
.breadcrumbs li { display: flex; gap: 8px; min-width: 0; overflow-wrap: anywhere; }
.breadcrumbs li + li::before { content: "/"; color: #999; }
.breadcrumbs a { text-underline-offset: 3px; }
.directory h1 { overflow-wrap: anywhere; line-height: 1.15; }
.page-description { margin: 0; color: #666; font-size: 15px; line-height: 1.8; max-width: 60ch; }
.section-list { list-style: none; padding: 0; margin: 36px 0 0; border-top: 1px solid #e4e4e4; }
.section-list li { border-bottom: 1px solid #e4e4e4; }
.section-list a { display: flex; justify-content: space-between; align-items: center; gap: 20px; padding: 22px 12px; min-height: 68px; text-decoration: none; line-height: 1.6; }
.section-list a:hover { background: #f0f0f0; }
.section-list a span:first-child { min-width: 0; overflow-wrap: anywhere; }
.section-list a span:last-child { flex-shrink: 0; color: #777; }
.return-link { margin: 32px 0 0; font-size: 13px; color: #666; line-height: 1.7; }
.return-link a { text-underline-offset: 4px; }
@media (max-width: 600px) { .nav { gap: 16px; } .nav-links { gap: 20px; } }

/* Compact native language selector within the horizontal header. */
.language-select { max-width: 70px; min-height: 32px; padding: 3px 2px; border: 1px solid #dedede; border-radius: 4px; background: #fafafa; color: #575757; font: inherit; font-size: 12px; }
.language-select:focus-visible { outline: 2px solid #555; outline-offset: 3px; }
@media (max-width: 600px) { .nav-links { gap: 12px; } .nav { gap: 12px; padding-inline: 16px; } }