/* css/site.css – home page, blog, carousel and footer (on top of theme-dark/light.css) */
:root { --qa-blue: #2563eb; --qa-green: #16a34a; --qa-red: #ef4444; --qa-yellow: #f59e0b; --qa-purple: #7c3aed; --qa-line: rgba(128,128,128,.28); --qa-soft: rgba(128,128,128,.08); }

.nav-inner { max-width: 1080px; }
.nav-links { flex-wrap: wrap; justify-content: flex-end; gap: 6px 14px; }
.nav-links a { white-space: nowrap; }
.nav-links a.on { font-weight: 800; }
.nav-langs { display: inline-flex; gap: 2px; align-items: center; margin-left: 6px; }
.nav-langs a { font-size: 12px; font-weight: 700; opacity: .65; padding: 4px 6px; border-radius: 6px; }
.nav-langs a.on { opacity: 1; background: rgba(37,99,235,.14); }
.junior-badge { position: absolute; top: 8px; right: 8px; background: #fde047; color: #1e1b4b; font-size: 11px; font-weight: 900; padding: 3px 8px; border-radius: 8px; transform: rotate(-6deg); letter-spacing: .04em; z-index: 2; }
.nav-burger { display: none; font: inherit; font-size: 22px; background: none; border: 0; color: inherit; cursor: pointer; padding: 2px 8px; }
@media (max-width: 760px) {
    .nav { position: relative; }
    .nav-inner { background: inherit; }
    .nav-burger { display: inline-block; }
    .nav-links { display: none; position: absolute; left: 0; right: 0; top: 100%; flex-direction: column; align-items: stretch; gap: 0; padding: 6px 0 10px; z-index: 50; background: inherit; border-bottom: 1px solid var(--qa-line); box-shadow: 0 16px 32px rgba(0,0,0,.45); }
    body.nav-open .nav-links { display: flex; }
    .nav-links a { font-size: 16px; padding: 13px 20px; border-bottom: 1px solid var(--qa-line); }
    .nav-links a:last-child { border-bottom: 0; }
    .nav-links a.on { background: rgba(37,99,235,.14); }
    .nav-langs { padding: 10px 20px; border-bottom: 1px solid var(--qa-line); } .nav-langs a { font-size: 14px; padding: 6px 10px; border: 0; }
    .nav-links a.nav-theme-toggle { border: 0; border-radius: 0; background: transparent; font-size: 14px; opacity: .8; padding-top: 10px; }
}

/* page frame used by the public content pages */
.page { max-width: 1080px; margin: 0 auto; padding: 16px 16px 48px; }
.page.narrow { max-width: 760px; }
.page h1 { font-size: clamp(28px, 5vw, 40px); margin: 14px 0 6px; line-height: 1.1; }
.lede { font-size: 18px; opacity: .85; margin: 0 0 18px; }
.muted { opacity: .7; }

/* hero */
.hero { display: grid; grid-template-columns: 1.1fr .9fr; gap: 28px; align-items: center; padding: 28px 0 10px; }
.hero .hero-logo { width: min(100%, 420px); display: block; margin: 0 auto; }
.hero h1 { font-size: clamp(32px, 5.4vw, 52px); margin: 0 0 10px; line-height: 1.05; letter-spacing: -.01em; }
.hero h1 .hl { background: linear-gradient(90deg, var(--qa-blue), var(--qa-purple)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero p { font-size: 18px; line-height: 1.5; margin: 0 0 18px; opacity: .9; }
.cta-row { display: flex; flex-wrap: wrap; gap: 10px; }
.btn-big { display: inline-flex; align-items: center; gap: 8px; padding: 13px 20px; border-radius: 999px; font-weight: 800; font-size: 16px; text-decoration: none; color: #fff; border: 0; cursor: pointer; font-family: inherit; }
.btn-big.blue { background: var(--qa-blue); } .btn-big.green { background: var(--qa-green); } .btn-big.red { background: var(--qa-red); }
.btn-big.ghost { background: transparent; border: 2px solid var(--qa-line); color: inherit; }
.btn-big.subscribe { background: #ff0033; color: #fff; }
.btn-big:hover { filter: brightness(1.08); text-decoration: none; }
@media (max-width: 760px) { .hero { grid-template-columns: 1fr; text-align: center; padding-top: 10px; } .hero .cta-row { justify-content: center; } .hero .hero-logo { width: min(80%, 300px); } }

/* join strip */
.join-strip { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin: 22px 0; }
.join-card { border: 1px solid var(--qa-line); border-radius: 18px; padding: 18px; background: var(--qa-soft); }
.join-card h2 { margin: 0 0 4px; font-size: 20px; }
.join-card .hint { font-size: 14px; opacity: .75; margin: 0 0 10px; }
.join-card form { display: grid; gap: 8px; }
.join-card input, .join-card select { width: 100%; padding: 11px 12px; border-radius: 10px; border: 1px solid var(--qa-line); background: transparent; color: inherit; font: inherit; }
.join-card .btn { width: 100%; }
.join-card .errors { border: 1px solid rgba(239,68,68,.6); border-radius: 10px; padding: 8px 12px; margin: 0 0 8px; font-size: 14px; }
.join-card .errors ul { margin: 0; padding-left: 18px; }
.join-card .small-note { font-size: 13px; opacity: .75; margin-top: 8px; }
.join-card .toggle-host { background: none; border: 0; color: var(--qa-blue); font: inherit; font-weight: 700; cursor: pointer; padding: 0; }
.reopen { border: 1px solid rgba(37,99,235,.5); border-radius: 12px; padding: 10px 14px; margin: 0 0 14px; font-size: 14px; }
@media (max-width: 760px) { .join-strip { grid-template-columns: 1fr; } }

/* section headers */
.section-head { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; margin: 34px 0 12px; }
.section-head h2 { margin: 0; font-size: clamp(22px, 3.4vw, 30px); }
.section-head a { font-weight: 700; }

/* carousel: horizontal scroll-snap track; the centre slide scales up */
.carousel { position: relative; margin: 0 -16px; }
.carousel-track { display: flex; gap: 18px; overflow-x: auto; scroll-snap-type: x mandatory; padding: 18px calc(50% - 150px) 22px; scrollbar-width: none; -webkit-overflow-scrolling: touch; }
.carousel-track::-webkit-scrollbar { display: none; }
.slide { flex: 0 0 300px; scroll-snap-align: center; border-radius: 18px; overflow: hidden; border: 1px solid var(--qa-line); background: var(--qa-soft); transform: scale(.86); opacity: .6; transition: transform .35s ease, opacity .35s ease, box-shadow .35s ease; }
.slide.is-center { transform: scale(1.04); opacity: 1; box-shadow: 0 18px 40px rgba(0,0,0,.35); }
.slide-pic { display: block; position: relative; aspect-ratio: 16/9; background: linear-gradient(135deg, #1d4ed8, #7c3aed); color: #fff; text-decoration: none; }
.slide-pic img { width: 100%; height: 100%; object-fit: cover; display: block; }
.slide-code { position: absolute; inset: 0; display: grid; place-items: center; font-weight: 900; font-size: 24px; letter-spacing: .05em; }
.play-badge { position: absolute; left: 50%; top: 50%; width: 58px; height: 58px; margin: -29px 0 0 -29px; border-radius: 50%; background: rgba(239,68,68,.95); color: #fff; display: grid; place-items: center; font-size: 24px; padding-left: 4px; box-shadow: 0 6px 18px rgba(0,0,0,.4); transition: transform .2s; }
.slide-pic:hover .play-badge { transform: scale(1.1); }
.slide-body { padding: 12px 14px 14px; }
.slide-body h3 { margin: 0 0 2px; font-size: 17px; line-height: 1.25; }
.slide-meta { font-size: 12px; opacity: .7; margin-bottom: 10px; }
.slide-actions { display: flex; gap: 6px; flex-wrap: wrap; }
.btn-mini { flex: 1; text-align: center; padding: 8px 10px; border-radius: 8px; font-weight: 700; font-size: 13px; text-decoration: none; color: #fff; white-space: nowrap; }
.btn-mini.host { background: var(--qa-blue); } .btn-mini.solo { background: var(--qa-green); } .btn-mini.watch { background: transparent; border: 1px solid var(--qa-line); color: inherit; }
.btn-mini:hover { filter: brightness(1.08); text-decoration: none; }
.carousel-btn { position: absolute; top: 38%; width: 42px; height: 42px; border-radius: 50%; border: 1px solid var(--qa-line); background: rgba(17,24,39,.85); color: #fff; font-size: 26px; line-height: 1; cursor: pointer; z-index: 2; display: grid; place-items: center; padding-bottom: 4px; }
.carousel-btn.prev { left: 10px; } .carousel-btn.next { right: 10px; }
@media (max-width: 760px) { .carousel-btn { display: none; } .carousel-track { padding-left: calc(50% - 135px); padding-right: calc(50% - 135px); } .slide { flex-basis: 270px; } }
@media (prefers-reduced-motion: reduce) { .slide { transition: none; } }

/* how it works */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.step { border: 1px solid var(--qa-line); border-radius: 18px; padding: 18px; background: var(--qa-soft); position: relative; }
.step .n { position: absolute; top: -12px; left: 16px; width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center; font-weight: 900; color: #fff; font-size: 14px; }
.step:nth-child(1) .n { background: var(--qa-red); } .step:nth-child(2) .n { background: var(--qa-blue); } .step:nth-child(3) .n { background: var(--qa-green); }
.step .icon { font-size: 34px; margin: 4px 0 6px; }
.step h3 { margin: 0 0 6px; font-size: 18px; }
.step p { margin: 0; font-size: 15px; line-height: 1.5; opacity: .85; }
@media (max-width: 760px) { .steps { grid-template-columns: 1fr; } }

/* for everyone */
.audience { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; }
.audience div { border-radius: 14px; padding: 14px; background: var(--qa-soft); border: 1px solid var(--qa-line); font-size: 14px; }
.audience strong { display: block; font-size: 16px; margin-bottom: 4px; }
@media (max-width: 760px) { .audience { grid-template-columns: 1fr 1fr; } }

/* blog cards + post body */
.post-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 16px; }
.post-card { border: 1px solid var(--qa-line); border-radius: 16px; overflow: hidden; background: var(--qa-soft); display: flex; flex-direction: column; }
.post-card .pic { aspect-ratio: 16/9; background: linear-gradient(135deg, #0ea5e9, #7c3aed); }
.post-card .pic img { width: 100%; height: 100%; object-fit: cover; display: block; }
.post-card .body { padding: 12px 14px 14px; display: flex; flex-direction: column; gap: 6px; flex: 1; }
.post-card h3 { margin: 0; font-size: 17px; }
.post-card h3 a { color: inherit; }
.post-card .date { font-size: 12px; opacity: .65; }
.post-card p { margin: 0; font-size: 14px; opacity: .85; flex: 1; }
.post-body { font-size: 17px; line-height: 1.6; }
.post-body h2 { font-size: 26px; margin: 28px 0 8px; } .post-body h3 { font-size: 21px; margin: 22px 0 6px; } .post-body h4 { font-size: 18px; margin: 18px 0 6px; }
.post-body img { max-width: 100%; border-radius: 12px; }
.post-body blockquote { border-left: 4px solid var(--qa-blue); margin: 14px 0; padding: 6px 14px; opacity: .9; }
.post-body code { background: var(--qa-soft); padding: 1px 6px; border-radius: 6px; font-size: .9em; }
.post-body .btn { margin: 4px 0; }
.embed { position: relative; aspect-ratio: 16/9; border-radius: 14px; overflow: hidden; background: #000; margin: 14px 0; }
.embed iframe, .embed video, .embed img { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; object-fit: cover; }
.ep-embed { border: 1px solid var(--qa-line); border-radius: 16px; padding: 12px; margin: 16px 0; background: var(--qa-soft); }
.ep-embed .embed { margin: 0 0 10px; }
.ep-embed p { margin: 6px 0 10px; font-size: 15px; }
.ep-missing { border: 1px dashed var(--qa-line); border-radius: 10px; padding: 10px; opacity: .7; }
.post-meta { font-size: 14px; opacity: .7; margin: 0 0 18px; }

/* footer */
.site-footer { border-top: 1px solid var(--qa-line); margin-top: 40px; padding: 26px 16px 34px; }
.foot-inner { max-width: 1080px; margin: 0 auto; display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap; align-items: flex-start; }
.foot-brand { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; font-size: 18px; }
.foot-brand .muted { width: 100%; font-size: 12px; letter-spacing: .18em; text-transform: uppercase; }
.foot-links { display: flex; gap: 14px; flex-wrap: wrap; font-size: 14px; align-items: center; }
.social-links { display: inline-flex; gap: 10px; align-items: center; }
.social-links a { display: inline-flex; padding: 4px; border-radius: 8px; color: inherit; opacity: .8; }
.social-links a:hover { opacity: 1; background: var(--qa-line); }
.social-links.holding { display: flex; justify-content: center; gap: 14px; margin: 0 0 10px; color: #fff; }
.social-links.holding a:hover { background: rgba(255,255,255,.15); }

/* quiz-code autocomplete */
.ac { position: relative; }
.ac-list { display: none; position: absolute; left: 0; right: 0; top: calc(100% + 4px); z-index: 60; margin: 0; padding: 6px; list-style: none; max-height: 360px; overflow-y: auto; border: 1px solid var(--qa-line); border-radius: 12px; background: #0f172a; color: #e5e7eb; box-shadow: 0 18px 40px rgba(0,0,0,.35); }
.ac-list li { display: flex; flex-direction: column; gap: 6px; padding: 8px 10px; border-radius: 9px; cursor: pointer; }
.ac-list li.on, .ac-list li:hover { background: var(--qa-blue); color: #fff; }
.ac-code { display: flex; align-items: center; gap: 8px; font-family: ui-monospace, Menlo, Consolas, monospace; font-weight: 800; font-size: 14px; letter-spacing: .03em; }
.ac-badge { font-family: system-ui, sans-serif; font-size: 10px; font-weight: 900; background: #fde047; color: #1e1b4b; padding: 2px 7px; border-radius: 6px; letter-spacing: .04em; }
.ac-flag { font-size: 13px; }
.ac-detail { display: flex; align-items: center; gap: 10px; }
.ac-thumb { flex: none; width: 72px; height: 40px; border-radius: 7px; overflow: hidden; background: rgba(128,128,128,.25); display: grid; place-items: center; font-size: 11px; font-weight: 800; opacity: .9; }
.ac-thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }
.ac-text { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.ac-title { font-weight: 700; font-size: 14px; }
.ac-meta { font-size: 12px; opacity: .75; }
.ac-list b { color: var(--qa-yellow); }
.ac-list li.on b, .ac-list li:hover b { color: #fde68a; }

/* The open list of a <select> is drawn by the system, usually on white: give options dark text so they stay readable
   in the dark theme (the closed box keeps the theme's colours). */
select option, select optgroup { color: #0f172a; background: #fff; }
select optgroup { font-weight: 700; color: #334155; }
select option:disabled { color: #94a3b8; }