/* ============================================================
   Stack School (lite) — design system
   Matches the v1 suite: dark, calm, gamified. File:// safe.
   ============================================================ */
:root {
  --bg-0:#0a0f14; --bg-1:#0e151c; --bg-2:#131c26; --bg-3:#18242f;
  --surface:#111a23; --surface-2:#16222e; --line:#213140; --line-2:#2c3f52;
  --text-0:#eaf2f8; --text-1:#b6c6d4; --text-2:#8298a8; --text-3:#5f7484;
  --primary:#2bd4a7; --primary-2:#14b894; --primary-ink:#032a22;
  --accent:#ffc24b; --accent-2:#ff9d3c; --info:#5aa9ff; --danger:#ff5d6c; --purple:#b08cff;
  --ring:rgba(43,212,167,0.55); --shadow:0 10px 30px rgba(0,0,0,0.45); --shadow-sm:0 4px 14px rgba(0,0,0,0.35);
  --radius:16px; --radius-sm:11px; --maxw:1120px;
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --mono:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,monospace;
}
:root[data-theme="light"]{
  --bg-0:#f3f6f9; --bg-1:#edf1f5; --bg-2:#e5ebf1; --bg-3:#d9e2ea;
  --surface:#fff; --surface-2:#f7fafc; --line:#d8e1e9; --line-2:#c2cfda;
  --text-0:#16222d; --text-1:#3c5163; --text-2:#64798b; --text-3:#8ba0b0;
  --primary:#0ca47e; --primary-2:#0a8a6a; --primary-ink:#fff;
  --accent:#c97e08; --accent-2:#b56a00; --info:#1f6fd6; --danger:#d6303f; --purple:#7a52d6;
  --ring:rgba(12,164,126,0.4); --shadow:0 10px 30px rgba(22,34,45,0.12); --shadow-sm:0 4px 14px rgba(22,34,45,0.09);
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  font-family:var(--font); color:var(--text-0); background:var(--bg-0);
  -webkit-font-smoothing:antialiased; min-height:100vh; line-height:1.55;
}
h1,h2,h3{line-height:1.2;margin:0 0 .4em}
h1{font-size:clamp(28px,5vw,46px);letter-spacing:-.02em}
h2{font-size:clamp(20px,3vw,28px)}
p{margin:0 0 1em;color:var(--text-1)}
a{color:var(--primary)}
small{color:var(--text-2)}

/* aurora background */
.bg-aurora{position:fixed;inset:0;z-index:-1;
  background:
    radial-gradient(60vw 60vw at 12% -10%, rgba(43,212,167,0.13), transparent 60%),
    radial-gradient(50vw 50vw at 100% 0%, rgba(90,169,255,0.10), transparent 55%),
    radial-gradient(60vw 60vw at 80% 110%, rgba(176,140,255,0.10), transparent 60%),
    var(--bg-0);
}
.bg-aurora::after{content:"";position:absolute;inset:0;
  background-image:radial-gradient(rgba(255,255,255,0.025) 1px, transparent 1px);
  background-size:22px 22px;}

.root{max-width:var(--maxw);margin:0 auto;padding:0 20px 80px;min-height:60vh}
.pad{padding:40px 20px}
.center{text-align:center}
.muted{color:var(--text-2)}
.stack{display:flex;flex-direction:column;gap:14px}
.row{display:flex;gap:12px;align-items:center;flex-wrap:wrap}
.spacer{flex:1}
.hidden,[hidden]{display:none!important}

/* appbar */
.appbar{position:sticky;top:0;z-index:50;backdrop-filter:blur(10px);
  background:rgba(14,21,28,0.72);border-bottom:1px solid var(--line)}
:root[data-theme="light"] .appbar{background:rgba(247,250,252,0.8)}
.appbar-inner{max-width:var(--maxw);margin:0 auto;padding:10px 20px;display:flex;align-items:center;gap:14px}
.brand{display:flex;align-items:center;gap:9px;background:none;border:0;cursor:pointer;padding:4px}
.brand-fox{font-size:22px}
.brand-name{font-weight:800;font-size:18px;letter-spacing:-.01em;
  background:linear-gradient(90deg,var(--text-0),var(--primary));-webkit-background-clip:text;background-clip:text;color:transparent}
.appbar-right{margin-left:auto;display:flex;align-items:center;gap:10px}

/* buttons */
.btn{appearance:none;border:1px solid var(--line-2);background:var(--surface-2);color:var(--text-0);
  font-family:inherit;font-size:15px;font-weight:650;padding:11px 18px;border-radius:var(--radius-sm);
  cursor:pointer;transition:transform .08s, border-color .15s, background .15s, box-shadow .15s;display:inline-flex;align-items:center;gap:8px}
.btn:hover{border-color:var(--line-2);transform:translateY(-1px)}
.btn:active{transform:translateY(0)}
.btn:disabled{opacity:.5;cursor:not-allowed;transform:none}
.btn.primary{background:linear-gradient(180deg,var(--primary),var(--primary-2));border-color:transparent;color:var(--primary-ink);box-shadow:0 6px 18px rgba(43,212,167,.28)}
.btn.ghost{background:transparent}
.btn.danger{border-color:rgba(255,93,108,.5);color:var(--danger)}
.btn.lg{padding:14px 26px;font-size:17px}
.btn.sm{padding:7px 12px;font-size:13px}
.btn.block{width:100%;justify-content:center}

/* pills / chips */
.pill{display:inline-flex;align-items:center;gap:7px;padding:7px 13px;border-radius:999px;
  border:1px solid var(--line-2);background:var(--surface-2);font-size:13px;font-weight:650;color:var(--text-1)}
.pill .ico{font-size:15px}
.pill.amber{border-color:rgba(255,194,75,.4);color:var(--accent)}
.pill.fire{border-color:rgba(255,157,60,.4);color:var(--accent-2)}
.pill.teal{border-color:rgba(43,212,167,.4);color:var(--primary)}
.chip{display:inline-flex;align-items:center;gap:8px;padding:10px 15px;border-radius:999px;
  border:1.5px solid var(--line-2);background:var(--surface-2);color:var(--text-0);cursor:pointer;
  font-size:14px;font-weight:650;transition:.12s;user-select:none}
.chip:hover{border-color:var(--primary)}
.chip[aria-pressed="true"]{border-color:var(--primary);background:rgba(43,212,167,.14);color:var(--primary)}

/* cards */
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow-sm)}
.card.pad,.card .pad{padding:22px}
.grid{display:grid;gap:16px}
.grid.cards{grid-template-columns:repeat(auto-fill,minmax(260px,1fr))}

/* course card */
.course{position:relative;overflow:hidden;display:flex;flex-direction:column;min-height:170px;
  border:1px solid var(--line);border-radius:var(--radius);background:var(--surface);box-shadow:var(--shadow-sm);
  transition:transform .1s, border-color .15s, box-shadow .15s}
.course:hover{transform:translateY(-2px);border-color:var(--line-2);box-shadow:var(--shadow)}
.course .top{padding:18px 18px 0;display:flex;align-items:flex-start;gap:12px}
.course .ico{font-size:30px;line-height:1}
.course .ttl{font-weight:750;font-size:17px;letter-spacing:-.01em}
.course .sub{color:var(--text-2);font-size:13px;margin-top:3px}
.course .meta{margin-top:auto;padding:14px 18px;display:flex;align-items:center;gap:10px;border-top:1px solid var(--line);font-size:12px;color:var(--text-2)}
.course .tag{font-size:11px;text-transform:uppercase;letter-spacing:.06em;color:var(--text-3)}
.course .x{position:absolute;top:10px;right:10px;width:30px;height:30px;border-radius:9px;border:1px solid var(--line-2);
  background:var(--surface-2);color:var(--text-2);cursor:pointer;font-size:15px;line-height:1;display:flex;align-items:center;justify-content:center;transition:.12s;z-index:2}
.course .x:hover{border-color:var(--danger);color:var(--danger)}
.course .matchbar{height:4px;background:var(--line)}
.course .matchbar i{display:block;height:100%;background:linear-gradient(90deg,var(--primary),var(--accent))}

/* active (current) course — prominent, full width */
.course.active{grid-column:1/-1;border-color:var(--primary);
  box-shadow:0 0 0 1px var(--primary), var(--shadow);
  background:linear-gradient(180deg, rgba(43,212,167,.07), var(--surface))}
.course.active .kicker{font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.08em;color:var(--primary);margin-bottom:3px}
.course.active .ico{font-size:38px}
.active-actions{display:flex;align-items:center;gap:14px;flex-wrap:wrap;padding:0 18px 16px}

/* "up next" header between active and locked */
.lock-head{grid-column:1/-1;margin:8px 2px -4px}
.lock-head .k{font-size:12px;text-transform:uppercase;letter-spacing:.06em;color:var(--text-3)}
.locked-grid{grid-column:1/-1}

/* locked / greyed preview cards */
.course.locked{opacity:.5;filter:grayscale(.35);cursor:default;min-height:150px}
.course.locked:hover{transform:none;border-color:var(--line);box-shadow:var(--shadow-sm)}
.course.locked .lockbadge{position:absolute;top:10px;right:10px;font-size:11px;font-weight:700;
  text-transform:uppercase;letter-spacing:.05em;color:var(--text-3);
  background:var(--surface-2);border:1px solid var(--line-2);border-radius:99px;padding:3px 9px;z-index:2}

/* inputs */
.field{display:block;margin-bottom:14px}
.field label{display:block;font-size:13px;font-weight:650;color:var(--text-1);margin-bottom:6px}
.input{width:100%;padding:12px 14px;border-radius:var(--radius-sm);border:1px solid var(--line-2);
  background:var(--bg-2);color:var(--text-0);font-family:inherit;font-size:15px}
.input:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px var(--ring)}
.formcard{max-width:420px;margin:6vh auto 0}
.err{color:var(--danger);font-size:13px;margin:8px 0 0;min-height:18px}

/* hero / landing */
.hero{text-align:center;padding:9vh 16px 4vh}
.hero .fox{font-size:64px}
.hero h1{margin-top:10px}
.hero .lead{font-size:clamp(16px,2.4vw,20px);color:var(--text-1);max-width:620px;margin:0 auto 26px}
.feature{display:flex;gap:14px;align-items:flex-start;text-align:left}
.feature .e{font-size:26px}
.feature h3{margin:0 0 4px;font-size:16px}
.feature p{font-size:14px;margin:0}

/* wizard */
.wizard{max-width:600px;margin:5vh auto 0}
.wizard .steps{display:flex;gap:6px;margin-bottom:24px}
.wizard .steps i{height:6px;flex:1;border-radius:99px;background:var(--line)}
.wizard .steps i.on{background:var(--primary)}
.wizard .steps i.done{background:var(--primary-2)}
.wizard h2{margin-bottom:6px}
.wizard .q{color:var(--text-2);margin-bottom:20px}
.optgrid{display:grid;gap:12px;grid-template-columns:repeat(auto-fit,minmax(150px,1fr))}
.opt{padding:16px;border-radius:var(--radius-sm);border:1.5px solid var(--line-2);background:var(--surface-2);
  cursor:pointer;font-weight:600;transition:.12s;display:flex;align-items:center;gap:10px}
.opt:hover{border-color:var(--primary)}
.opt[aria-pressed="true"]{border-color:var(--primary);background:rgba(43,212,167,.14)}
.opt .e{font-size:22px}

/* account header / stats */
.statbar{display:grid;gap:14px;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));margin:18px 0 26px}
.stat{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:16px 18px}
.stat .k{font-size:12px;text-transform:uppercase;letter-spacing:.07em;color:var(--text-3)}
.stat .v{font-size:26px;font-weight:800;margin-top:4px;display:flex;align-items:center;gap:8px}
.stat .v small{font-size:13px;font-weight:600;color:var(--text-2)}
.levelbar{height:8px;border-radius:99px;background:var(--line);overflow:hidden;margin-top:10px}
.levelbar i{display:block;height:100%;background:linear-gradient(90deg,var(--primary),var(--accent))}
.section-head{display:flex;align-items:center;gap:12px;margin:30px 0 14px}
.section-head h2{margin:0}

/* toast */
.toast{position:fixed;left:50%;bottom:28px;transform:translate(-50%,20px);z-index:200;
  background:var(--surface-2);border:1px solid var(--line-2);color:var(--text-0);
  padding:12px 18px;border-radius:999px;box-shadow:var(--shadow);font-weight:650;font-size:14px;opacity:0;transition:.3s}
.toast.show{opacity:1;transform:translate(-50%,0)}
.toast.good{border-color:rgba(43,212,167,.5)}
.toast.bad{border-color:rgba(255,93,108,.5)}

/* footer */
.footer{margin-top:64px;border-top:1px solid var(--line);background:transparent}
.footer-inner{max-width:var(--maxw);margin:0 auto;padding:22px 20px;display:flex;align-items:center;gap:14px;flex-wrap:wrap;font-size:14px;color:var(--text-2)}
.footer-links{margin-left:auto;display:flex;gap:16px;flex-wrap:wrap}
.footer-links a{color:var(--text-2);text-decoration:none}
.footer-links a:hover{color:var(--primary)}
.footer-brand{font-weight:700;color:var(--text-0)}

/* quest tiles */
.quest{position:relative;background:var(--surface-2);border:1px solid var(--line);border-radius:14px;padding:16px}
.quest .q-top{display:flex;align-items:center;gap:6px}
.quest .q-ico{font-size:22px;margin-right:8px}
.quest .q-reward{margin-left:auto;font-size:12px;font-weight:700;color:var(--accent);white-space:nowrap}
.questbar{height:8px;border-radius:999px;background:var(--line);overflow:hidden;margin-top:12px}
.questbar i{display:block;height:100%;background:linear-gradient(90deg,var(--primary),var(--accent));transition:width .4s}
.quest.done{border-color:var(--primary);background:rgba(43,212,167,.08)}
.quest.done .q-check{color:var(--primary);font-weight:700}

/* completed-course cards */
.done-grid{grid-column:1/-1}
.course.done-card{min-height:120px;opacity:.92}
.course.done-card .top{padding-right:92px}
.course.done-card:hover{transform:translateY(-2px)}
.donebadge{position:absolute;top:10px;right:10px;font-size:11px;font-weight:700;color:var(--primary);background:rgba(43,212,167,.12);border:1px solid rgba(43,212,167,.4);border-radius:999px;padding:3px 9px}

@media(max-width:560px){
  .root{padding:0 14px 60px}
  .wizard,.formcard{margin-top:24px}

  /* ---- appbar: keep it on one row at phone widths ----
     Before this, the brand + 4 stat pills + Log out overflowed ~85px past
     a 390px viewport: the Log out button fell off-screen and the whole page
     scrolled sideways. The statbar right below already shows every stat, so
     on phones we hide the brand wordmark (fox stays) and the two redundant
     plain pills (level name + X's), keeping the motivating streak + XP pills
     and a reachable Log out. */
  .appbar-inner{gap:10px;padding:10px 14px}
  .brand{flex:0 0 auto;padding:4px 0}
  .brand-name{display:none}
  .appbar-right{gap:8px;min-width:0;flex-wrap:nowrap}
  #appbarRight .pill:not(.fire):not(.amber){display:none}
  #appbarRight .pill{padding:6px 10px;font-size:12px}
  #appbarRight .btn.sm{padding:8px 12px}
}

@media(max-width:560px){
  .footer-inner{flex-direction:column;align-items:flex-start;gap:8px}
  .footer-links{margin-left:0}
}