/* local-ai-lab course site — shared styles */
:root {
  --bg: #0f1115; --panel: #1a1d24; --panel2: #11141a; --edge: #2a2f3a;
  --txt: #e6e8ee; --muted: #8b93a7; --accent: #5b9dff; --accent2: #3a6fd8;
  --ok: #3fb950; --warn: #d29922; --code: #0c0e13;
  --maxw: 920px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0; background: var(--bg); color: var(--txt);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code, pre, kbd { font-family: "SF Mono", ui-monospace, "Cascadia Code", Menlo, Consolas, monospace; }

/* ---- top bar ---- */
.topbar {
  position: sticky; top: 0; z-index: 20; backdrop-filter: blur(8px);
  background: rgba(15,17,21,.85); border-bottom: 1px solid var(--edge);
}
.topbar .inner {
  max-width: var(--maxw); margin: 0 auto; padding: 12px 20px;
  display: flex; align-items: center; gap: 16px;
}
.brand { font-weight: 700; font-size: 16px; color: var(--txt); }
.brand .dot { color: var(--accent); }
.topbar nav { margin-left: auto; display: flex; gap: 16px; flex-wrap: wrap; font-size: 14px; align-items: center; }

/* ---- lessons dropdown menu ---- */
.nav-dd { position: relative; }
.nav-dd > summary { cursor: pointer; list-style: none; color: var(--accent); }
.nav-dd > summary::-webkit-details-marker { display: none; }
.nav-dd > summary::after { content: " \25BE"; }
.nav-dd[open] > summary::after { content: " \25B4"; }
.nav-dd > summary:hover { color: var(--txt); }
.nav-dd-menu {
  position: absolute; right: 0; top: 175%; min-width: 240px; z-index: 60;
  display: flex; flex-direction: column; gap: 2px; padding: 6px;
  background: var(--panel); border: 1px solid var(--edge); border-radius: 10px;
  box-shadow: 0 10px 28px rgba(0,0,0,.45);
}
.nav-dd-menu a { padding: 7px 10px; border-radius: 6px; color: var(--txt); white-space: nowrap; }
.nav-dd-menu a:hover { background: var(--panel2); text-decoration: none; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 28px 20px 64px; }

/* ---- hero banner image ---- */
.hero-banner { display: block; width: 100%; height: auto; border-radius: 16px; border: 1px solid var(--edge); margin: 8px 0 4px; }

/* ---- hero / landing ---- */
.hero { padding: 56px 0 24px; }
.hero h1 { font-size: 44px; line-height: 1.1; margin: 0 0 12px; }
.hero .tag { color: var(--muted); font-size: 20px; max-width: 640px; }
.btn {
  display: inline-block; background: var(--accent2); color: #fff; border: none;
  padding: 11px 20px; border-radius: 10px; font-weight: 600; cursor: pointer;
}
.btn:hover { background: var(--accent); text-decoration: none; }
.btn.ghost { background: transparent; border: 1px solid var(--edge); color: var(--txt); }
.cta { margin: 26px 0 8px; display: flex; gap: 12px; flex-wrap: wrap; }

.cards { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); margin: 28px 0; }
.card { background: var(--panel); border: 1px solid var(--edge); border-radius: 14px; padding: 20px; }
.card h3 { margin: 0 0 6px; font-size: 17px; }
.card .num { color: var(--accent); font-weight: 700; }
.card .status { font-size: 12px; color: var(--muted); margin-top: 10px; }
.badge { display: inline-block; font-size: 11px; padding: 2px 8px; border-radius: 999px; border: 1px solid var(--edge); }
.badge.ok { color: var(--ok); border-color: #1f5130; }
.badge.soon { color: var(--warn); border-color: #5a4a1a; }

table { border-collapse: collapse; width: 100%; margin: 18px 0; }
th, td { border: 1px solid var(--edge); padding: 9px 12px; text-align: left; font-size: 14px; }
th { background: var(--panel); }

/* ---- slider / deck ---- */
.lesson-head { padding: 18px 0 8px; }
.lesson-head .eyebrow { color: var(--accent); font-weight: 700; letter-spacing: .04em; text-transform: uppercase; font-size: 13px; }
.lesson-head h1 { margin: 6px 0 6px; font-size: 30px; }
.lesson-head p { color: var(--muted); margin: 0; }

/* ---- language selector (Python / Node.js / C#) ---- */
.langsel { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; margin: 14px 0 2px; }
.langsel-label { color: var(--muted); font-size: 13px; margin-right: 2px; }
.langsel-btn {
  background: var(--panel); border: 1px solid var(--edge); color: var(--muted);
  padding: 6px 14px; border-radius: 999px; cursor: pointer; font: inherit; font-size: 13px; font-weight: 600;
}
.langsel-btn:hover { color: var(--txt); border-color: var(--accent); }
.langsel-btn.on { background: var(--accent2); border-color: var(--accent); color: #fff; }
.langsel.compact { margin: 0; }
.langsel.compact .langsel-btn { padding: 5px 11px; font-size: 12px; }

/* Per-language content: show only the blocks for the active language. The root
   <html data-lang="..."> is set by an inline head script + slider.js. Using
   display:contents so the wrapper adds no box (works for block and inline). */
.lang { display: none; }
[data-lang="python"] .lang-python,
[data-lang="node"]   .lang-node,
[data-lang="csharp"] .lang-csharp { display: contents; }

.progress { height: 4px; background: var(--edge); border-radius: 999px; overflow: hidden; margin: 18px 0 8px; }
.progress > span { display: block; height: 100%; width: 0; background: linear-gradient(90deg, var(--accent2), var(--accent)); transition: width .35s ease; }

.dots { display: flex; flex-wrap: wrap; gap: 7px; margin: 0 0 14px; }
.dots button {
  width: 11px; height: 11px; padding: 0; border-radius: 50%; cursor: pointer;
  border: 1px solid var(--edge); background: transparent; transition: .2s;
}
.dots button.on { background: var(--accent); border-color: var(--accent); transform: scale(1.15); }
.dots button:hover { border-color: var(--accent); }

.deck { position: relative; transition: height .35s ease; }
.slide {
  position: absolute; top: 0; left: 0; width: 100%;
  opacity: 0; transform: translateX(28px); pointer-events: none; visibility: hidden;
  transition: opacity .35s ease, transform .35s ease, visibility 0s linear .35s;
}
.slide.active {
  opacity: 1; transform: none; pointer-events: auto; visibility: visible;
  transition: opacity .35s ease, transform .35s ease, visibility 0s;
}

.slide .step-no { color: var(--accent); font-weight: 700; font-size: 14px; }
.slide h2 { margin: 4px 0 6px; font-size: 24px; }
.slide .why {
  background: rgba(91,157,255,.07); border-left: 3px solid var(--accent2);
  padding: 12px 16px; border-radius: 0 10px 10px 0; margin: 14px 0; color: #d7dcea;
}
.slide .why b { color: var(--txt); }
.note { background: rgba(210,153,34,.08); border-left: 3px solid var(--warn); padding: 12px 16px; border-radius: 0 10px 10px 0; margin: 14px 0; }
.slide p { margin: 12px 0; }

/* command + code blocks */
.block { position: relative; margin: 14px 0; }
.block .label { font-size: 11px; text-transform: uppercase; letter-spacing: .05em; color: var(--muted); margin-bottom: 6px; }
pre {
  background: var(--code); border: 1px solid var(--edge); border-radius: 10px;
  padding: 14px 16px; overflow-x: auto; margin: 0; font-size: 13.5px; line-height: 1.55;
}
pre.cmd { border-color: #244; }
pre.cmd::before { content: "$ "; color: var(--ok); }
pre code { color: #d7dcea; white-space: pre; }
.copy {
  position: absolute; top: 8px; right: 8px; font-size: 11px; padding: 4px 9px;
  border-radius: 7px; border: 1px solid var(--edge); background: var(--panel);
  color: var(--muted); cursor: pointer;
}
.copy:hover { color: var(--txt); border-color: var(--accent); }
.copy.done { color: var(--ok); border-color: #1f5130; }

/* nav controls */
.controls { display: flex; align-items: center; gap: 12px; margin-top: 22px; }
.controls .spacer { flex: 1; }
.nav-btn {
  background: var(--panel); border: 1px solid var(--edge); color: var(--txt);
  padding: 9px 16px; border-radius: 10px; cursor: pointer; font: inherit; font-weight: 600;
}
.nav-btn:hover:not(:disabled) { border-color: var(--accent); }
.nav-btn:disabled { opacity: .4; cursor: default; }
.counter { color: var(--muted); font-size: 13px; }
.kbd-hint { color: var(--muted); font-size: 12px; margin-top: 12px; text-align: center; }
kbd { background: var(--panel); border: 1px solid var(--edge); border-bottom-width: 2px; border-radius: 5px; padding: 1px 6px; font-size: 12px; }

footer.site { border-top: 1px solid var(--edge); color: var(--muted); font-size: 13px; }
footer.site .inner { max-width: var(--maxw); margin: 0 auto; padding: 22px 20px; }

@media (max-width: 600px) {
  .hero h1 { font-size: 32px; }
  .slide h2 { font-size: 20px; }
}