/* ════════════════════════════════════════════════════════════
   AURORA SKIN (preview): the landing-page look, inside the app.
   Fully reversible: applies ONLY when <html data-skin="aurora">.
   Toggle it in Settings or the side menu. To remove the feature
   entirely, delete this file, its <link> in app.html, and the
   skin toggle lines marked "aurora skin" in app.html.
════════════════════════════════════════════════════════════ */
@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@500;600;700&display=swap');

html[data-skin="aurora"]{
  --bg:#070b18;--panel:#101a36;--ink:#eef1fb;--muted:#9aa5c3;
  --line:#212e52;--accent:#9d8fff;--accent2:#ffb454;--gold:#ffb454;
  --accent-soft:#7c6bff26;--good:#3ce0a0;--bad:#ff6b6b;--warn:#ffb454;
  --grad:linear-gradient(135deg,#7c6bff,#5a8bff);
  --wash:#7c6bff1a;--stem:#8fa0d8;
  --shadow:0 1px 4px #01030a66,0 8px 28px #01030a55;
  --shadow-lg:0 18px 55px #01030a88;
  --font-display:"Space Grotesk","Plus Jakarta Sans","Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;
}

/* aurora background: violet + blue + teal glows over the dark base */
html[data-skin="aurora"] body{
  background-color:var(--bg);
  background-image:
    radial-gradient(760px 520px at 12% -6%,#7c6bff30,transparent 62%),
    radial-gradient(900px 600px at 92% 4%,#5a8bff2a,transparent 60%),
    radial-gradient(640px 480px at 74% 96%,#3ce0d01c,transparent 62%),
    url("stem-bg-dark.svg");
  background-repeat:no-repeat,no-repeat,no-repeat,repeat;
  background-size:100% 900px,100% 900px,100% 900px,600px 600px;
}

/* glassy panels and header, like the landing page cards */
html[data-skin="aurora"] .bar{background:#070b18cc;backdrop-filter:blur(14px);border-bottom:1px solid var(--line)}
html[data-skin="aurora"] .rail-card,
html[data-skin="aurora"] .subj-card,
html[data-skin="aurora"] .course-card,
html[data-skin="aurora"] .ach-card,
html[data-skin="aurora"] .side-drawer,
html[data-skin="aurora"] .stat-tile{
  background:linear-gradient(165deg,#ffffff10,#ffffff08);
  border-color:var(--line);
}
html[data-skin="aurora"] .rail-card:hover,
html[data-skin="aurora"] .subj-card:hover,
html[data-skin="aurora"] .course-card:hover{border-color:#3a4a7d}

/* hero banner: aurora gradient instead of navy */
html[data-skin="aurora"] .learn-hero{
  background:
    radial-gradient(420px 260px at 88% 0%,#3ce0d033,transparent 65%),
    linear-gradient(135deg,#4c3dd4,#5a8bff);
}

/* amber CTAs, like the landing page */
html[data-skin="aurora"] .lh-btn,
html[data-skin="aurora"] .nav-cta{
  background:linear-gradient(135deg,#ffb454,#ff8a3d);color:#2b1503;
}

/* gradient shimmer on the big page titles */
html[data-skin="aurora"] .page-title{
  background:linear-gradient(100deg,#eef1fb 30%,#a78bfa 55%,#3ce0d0 80%);
  background-size:200% auto;-webkit-background-clip:text;background-clip:text;
  -webkit-text-fill-color:transparent;color:transparent;
}

/* inputs on dark glass */
html[data-skin="aurora"] input,
html[data-skin="aurora"] select,
html[data-skin="aurora"] textarea{background:#0c1329;border-color:var(--line);color:var(--ink)}

@media(prefers-reduced-motion:reduce){
  html[data-skin="aurora"] .page-title{animation:none}
}
