/* Home page (/). Night-sky hero (search + upload call), then the course shelf and the upload form.
   Builds on cs2040c/assets/cs.css + assets/lumina-ui.css + file-upload/upload.css. */
.home { --night: #070720; --night-2: #120f3a; --glow: #a78bfa; font-family: var(--lu-sans); }
.home .page.wide { max-width: 1080px; }

/* top bar over the night sky */
.topbar.dark { position: absolute; top: 0; left: 0; right: 0; z-index: 5; background: transparent; border-bottom: 1px solid rgba(255,255,255,.08); backdrop-filter: none; -webkit-backdrop-filter: none; }
.topbar.dark .in { max-width: 1080px; }
.topbar.dark .brand { color: #fff; }
.topbar.dark nav a { color: rgba(255,255,255,.72); }
.topbar.dark nav a:hover { color: #fff; }
.topbar.dark #acct button { background: rgba(255,255,255,.08); border-color: rgba(255,255,255,.22); color: #fff; }

/* night sky */
.sky { position: relative; overflow: hidden; color: #fff; padding: 120px 20px 80px;
  background: radial-gradient(900px 500px at 80% 10%, rgba(124,58,237,.38), transparent 65%), radial-gradient(700px 420px at 5% 90%, rgba(6,182,212,.16), transparent 60%),
    radial-gradient(600px 400px at 60% 120%, rgba(236,72,153,.22), transparent 60%), linear-gradient(180deg, var(--night) 0%, var(--night-2) 100%); }
.sky::after { content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 80px; background: linear-gradient(180deg, transparent, rgba(245,244,255,.06)); pointer-events: none; }
#stars { position: absolute; inset: 0; width: 100%; height: 100%; }
.sky-in { position: relative; z-index: 1; max-width: 1040px; margin: 0 auto; display: grid; grid-template-columns: 1.1fr .9fr; gap: 36px; align-items: center; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; margin: 0 0 18px; padding: 6px 12px; border-radius: 999px; border: 1px solid rgba(255,255,255,.16); background: rgba(255,255,255,.06); font-size: 13px; letter-spacing: .02em; color: rgba(255,255,255,.82); }
.eyebrow i { width: 7px; height: 7px; border-radius: 50%; background: #34d399; box-shadow: 0 0 10px #34d399; }
.sky h1 { margin: 0; color: #fff; font-family: var(--lu-serif); font-weight: 650; font-size: clamp(42px, 6.6vw, 72px); line-height: 1; letter-spacing: -.03em; }
.sky .grad { background: linear-gradient(100deg, #a5b4fc 0%, #c084fc 40%, #f472b6 80%); -webkit-background-clip: text; background-clip: text; color: transparent; }
.sky .sub { margin: 18px 0 0; font-size: clamp(17px, 2.1vw, 20px); line-height: 1.5; color: rgba(255,255,255,.74); }
.sky .sub b { color: #fff; font-weight: 600; }

/* search */
.find { position: relative; margin: 26px 0 0; max-width: 520px; }
.find input { width: 100%; box-sizing: border-box; padding: 15px 18px 15px 48px; font: 16px var(--lu-sans); color: #fff; border-radius: 14px; border: 1px solid rgba(255,255,255,.2);
  background: rgba(255,255,255,.08) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='20' height='20' fill='none' stroke='%23c4b5fd' stroke-width='2' viewBox='0 0 24 24'%3E%3Ccircle cx='11' cy='11' r='7'/%3E%3Cpath d='m20 20-3.5-3.5'/%3E%3C/svg%3E") 16px 50% no-repeat;
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); transition: border-color .2s, box-shadow .2s, background-color .2s; }
.find input::placeholder { color: rgba(255,255,255,.55); }
.find input:focus { outline: none; border-color: rgba(196,181,253,.8); background-color: rgba(255,255,255,.12); box-shadow: 0 0 0 4px rgba(167,139,250,.18), 0 10px 40px -10px rgba(167,139,250,.5); }
.hits { position: absolute; z-index: 10; left: 0; right: 0; margin: 8px 0 0; padding: 6px; list-style: none; background: #fff; border-radius: 14px; box-shadow: 0 24px 60px -16px rgba(0,0,0,.55); color: var(--lu-ink); }
.hits li { border-radius: 10px; }
.hits li:hover { background: #f5f4ff; }
.hits a.hit { display: flex; align-items: center; gap: 12px; padding: 10px 12px; color: var(--lu-ink); text-decoration: none; }
.hits .t { display: flex; flex-direction: column; min-width: 0; }
.hits .t small { color: var(--lu-muted); font-size: 12.5px; }
.hits .go { margin-left: auto; color: var(--lu-primary); font-weight: 600; font-size: 14px; }
.hits .none { display: flex; justify-content: space-between; align-items: center; gap: 10px; padding: 10px 12px; color: var(--lu-muted); font-size: 14.5px; }
.hits .none:hover { background: none; }
.home .code { font: 600 12px var(--lu-sans); color: var(--lu-primary); letter-spacing: .04em; min-width: 64px; }

/* buttons */
.cta { display: flex; gap: 12px; flex-wrap: wrap; margin: 22px 0 0; }
.btn.big { font-size: 16.5px; padding: 13px 24px; text-decoration: none; display: inline-block; border-radius: 12px; }
.btn.glow { background: linear-gradient(135deg, #6366f1, #a855f7 60%, #ec4899); box-shadow: 0 10px 30px -8px rgba(168,85,247,.7); }
.btn.glow:hover { box-shadow: 0 14px 38px -8px rgba(168,85,247,.9); }
.btn.glass { background: rgba(255,255,255,.06); color: #fff; border: 1px solid rgba(255,255,255,.22); box-shadow: none; }
.btn.glass:hover { background: rgba(255,255,255,.12); }

/* hero art on the night sky */
.hero-art .uh-art { height: 270px; }
.hero-art .uh-slide { background: rgba(255,255,255,.1); border-color: rgba(255,255,255,.14); filter: none; opacity: .75; }
.hero-art .uh-slt { color: rgba(255,255,255,.6); }
.hero-art .uh-slide i { background: rgba(255,255,255,.18); }
.hero-art .uh-arrow { color: #c4b5fd; text-shadow: 0 0 12px rgba(167,139,250,.8); }
.hero-art .uh-game { box-shadow: 0 30px 70px -20px rgba(0,0,0,.6), 0 0 0 1px rgba(255,255,255,.12), 0 0 60px -10px rgba(167,139,250,.55); }

.facts { position: relative; z-index: 1; list-style: none; max-width: 1040px; margin: 40px auto 0; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; border-radius: 16px; overflow: hidden; background: rgba(255,255,255,.1); }
.facts li { padding: 16px 20px; background: rgba(10,9,40,.55); backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px); display: flex; flex-direction: column; }
.facts b { font-family: var(--lu-serif); font-size: 19px; color: #fff; }
.facts span { color: rgba(255,255,255,.66); font-size: 14.5px; }

/* sections */
.sec-head { margin: 64px 0 18px; }
.sec-head h2 { margin: 0 0 6px; font-size: clamp(26px, 3.6vw, 34px); letter-spacing: -.02em; }
.sec-head p { margin: 0; color: var(--lu-muted); }
.sec-head p b { color: var(--lu-ink); }

/* course shelf */
.shelf { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 16px; }
.ccard { display: flex; flex-direction: column; background: #fff; border: 1px solid var(--lu-line); border-radius: 18px; overflow: hidden; color: var(--lu-ink); text-decoration: none; box-shadow: var(--lu-shadow); transition: transform .2s, box-shadow .2s, border-color .2s; }
.ccard:hover { transform: translateY(-3px); border-color: #cfc8f7; box-shadow: 0 2px 4px rgba(40,30,110,.06), 0 24px 44px -18px rgba(91,78,240,.45); }
.cart { position: relative; height: 112px; display: flex; align-items: flex-end; padding: 12px 14px; box-sizing: border-box; overflow: hidden; }
.cart span { position: relative; z-index: 1; font: 700 13px var(--lu-sans); letter-spacing: .08em; color: #fff; padding: 3px 9px; border-radius: 99px; background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.25); backdrop-filter: blur(4px); }
.cart.space { background: radial-gradient(circle at 78% 42%, #fde68a 0 9px, transparent 10px), radial-gradient(ellipse 44px 12px at 78% 42%, transparent 30px, rgba(253,230,138,.6) 31px, transparent 33px), radial-gradient(1px 1px at 20% 30%, #fff 50%, transparent 51%), radial-gradient(1px 1px at 45% 70%, #fff 50%, transparent 51%), radial-gradient(1.5px 1.5px at 60% 20%, #fff 50%, transparent 51%), radial-gradient(1px 1px at 90% 80%, #fff 50%, transparent 51%), linear-gradient(135deg, #0b1030, #312e81 60%, #7e22ce); }
.cart.grid { background: repeating-linear-gradient(90deg, rgba(255,255,255,.08) 0 1px, transparent 1px 22px), repeating-linear-gradient(0deg, rgba(255,255,255,.08) 0 1px, transparent 1px 22px), linear-gradient(135deg, #1e1b4b, #4f46e5 60%, #06b6d4); }
.cart.wave { background: radial-gradient(120px 60px at 80% 30%, rgba(255,255,255,.18), transparent 70%), linear-gradient(135deg, #3b0764, #7c3aed 55%, #ec4899); }
.cart.plus { background: repeating-linear-gradient(135deg, #f5f3ff 0 10px, #ede9fe 10px 20px); }
.cart.plus span { color: var(--lu-primary); background: #fff; border-color: #ddd6fe; font-size: 18px; padding: 0 11px; }
.cbody { display: flex; flex-direction: column; gap: 3px; padding: 14px 16px 16px; flex: 1; }
.cbody b { font-family: var(--lu-serif); font-size: 19px; line-height: 1.2; }
.cbody small { color: var(--lu-muted); font-size: 13px; }
.cbody .go { margin-top: auto; padding-top: 10px; color: var(--lu-primary); font-weight: 600; font-size: 14px; }
.ccard.add { border-style: dashed; box-shadow: none; }

/* upload */
.steps { list-style: none; counter-reset: s; margin: 0 0 4px; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.steps li { counter-increment: s; display: flex; flex-direction: column; padding: 12px 14px 12px 54px; position: relative; background: #fff; border: 1px solid var(--lu-line); border-radius: 14px; font-size: 14px; color: var(--lu-muted); }
.steps li::before { content: counter(s); position: absolute; left: 14px; top: 50%; transform: translateY(-50%); width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center; background: var(--lu-btn); color: #fff; font-weight: 700; font-size: 14px; }
.steps b { color: var(--lu-ink); font-size: 15.5px; }
.upload-wrap { scroll-margin-top: 10px; }
.home .foot { margin-top: 48px; }
.home .foot a { color: var(--lu-muted); }

@media (max-width: 820px) {
  .sky { padding-top: 92px; }
  .sky-in { grid-template-columns: 1fr; gap: 26px; }
  .hero-art .uh-art { height: 210px; max-width: 440px; }
  .facts, .steps { grid-template-columns: 1fr; }
  .topbar.dark nav a[href="#find"] { display: none; }
}
@media (prefers-reduced-motion: reduce) { .ccard { transition: none; } }