/* LevelUp Learning — game-flavoured dark theme */
:root {
  --bg: #0b1020;
  --bg-2: #101731;
  --panel: #151d3b;
  --panel-2: #1a2449;
  --line: #263263;
  --text: #e8ecff;
  --muted: #93a0c9;
  --accent: #4cc9f0;
  --accent-2: #f72585;
  --good: #43d67c;
  --warn: #ffd60a;
  --bad: #ff5d5d;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(0, 0, 0, .35);
  font-size: 16px;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: radial-gradient(1200px 600px at 80% -10%, #1b2a5e 0%, var(--bg) 55%) fixed;
  color: var(--text);
  font-family: "Segoe UI", system-ui, -apple-system, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  min-height: 100vh;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code {
  background: #0d1430; border: 1px solid var(--line); border-radius: 6px;
  padding: .08em .4em; font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; font-size: .88em;
}
pre {
  background: #0d1430; border: 1px solid var(--line); border-radius: 10px;
  padding: 12px 16px; overflow-x: auto; font-size: .85rem;
}
table { border-collapse: collapse; width: 100%; margin: 12px 0; font-size: .92rem; }
th, td { border: 1px solid var(--line); padding: 8px 12px; text-align: left; vertical-align: top; }
th { background: var(--panel-2); }
blockquote {
  margin: 14px 0; padding: 10px 18px; border-left: 4px solid var(--accent);
  background: rgba(76, 201, 240, .07); border-radius: 0 10px 10px 0; color: #cfe3ff;
}
img { max-width: 100%; border-radius: 10px; }

/* Header ---------------------------------------------------------------- */
#app-header {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(10px);
  background: rgba(11, 16, 32, .82);
  border-bottom: 1px solid var(--line);
}
.hdr-inner {
  max-width: 1100px; margin: 0 auto; padding: 10px 20px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 1.15rem; color: var(--text); }
.brand:hover { text-decoration: none; }
.brand-mark { filter: drop-shadow(0 0 8px var(--accent)); }
.brand-name { background: linear-gradient(90deg, var(--accent), #b5179e); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hdr-stats { display: flex; gap: 12px; align-items: stretch; }
.stat-chip {
  display: flex; gap: 10px; align-items: center;
  background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 6px 14px;
}
.chip-icon { font-size: 1.35rem; }
.chip-label { font-weight: 700; font-size: .82rem; line-height: 1.2; }
.chip-sub { color: var(--muted); font-size: .7rem; line-height: 1.2; }
.xp-track { width: 130px; height: 7px; background: #0d1430; border-radius: 99px; overflow: hidden; margin: 3px 0; }
.xp-fill { height: 100%; background: linear-gradient(90deg, var(--accent), #b5179e); border-radius: 99px; transition: width .6s ease; }

main { max-width: 1100px; margin: 0 auto; padding: 28px 20px 80px; }

/* Hero ------------------------------------------------------------------- */
.hero { padding: 30px 0 10px; }
.hero h1 { font-size: 2rem; margin: 0 0 6px; }
.hero .sub { color: var(--muted); max-width: 720px; }
.kpis { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 14px; margin: 22px 0 8px; }
.kpi { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px 18px; }
.kpi .v { font-size: 1.5rem; font-weight: 800; }
.kpi .l { color: var(--muted); font-size: .78rem; text-transform: uppercase; letter-spacing: .06em; }

/* Concept cards ----------------------------------------------------------- */
.section-title { margin: 34px 0 14px; font-size: 1.15rem; color: var(--muted); text-transform: uppercase; letter-spacing: .1em; }
.concept-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 18px; }
.concept-card {
  position: relative; display: block; color: var(--text);
  background: linear-gradient(160deg, var(--panel) 0%, var(--bg-2) 100%);
  border: 1px solid var(--line); border-radius: var(--radius); padding: 20px;
  transition: transform .15s ease, border-color .15s ease, box-shadow .15s ease;
}
.concept-card:hover { text-decoration: none; transform: translateY(-3px); box-shadow: var(--shadow); }
.concept-card.locked { opacity: .55; cursor: not-allowed; }
.concept-card .icon { font-size: 2rem; }
.concept-card h3 { margin: 8px 0 4px; font-size: 1.15rem; }
.concept-card p { margin: 0; color: var(--muted); font-size: .85rem; min-height: 3.2em; }
.concept-card .bar { margin-top: 14px; }
.status-pill {
  position: absolute; top: 14px; right: 14px; font-size: .68rem; font-weight: 700;
  padding: 3px 10px; border-radius: 99px; letter-spacing: .04em;
}
.status-pill.ready { background: rgba(67, 214, 124, .15); color: var(--good); border: 1px solid rgba(67, 214, 124, .4); }
.status-pill.soon { background: rgba(147, 160, 201, .12); color: var(--muted); border: 1px solid var(--line); }

.bar { height: 8px; background: #0d1430; border-radius: 99px; overflow: hidden; }
.bar .fill { height: 100%; border-radius: 99px; background: linear-gradient(90deg, var(--accent), var(--good)); }
.bar-label { display: flex; justify-content: space-between; font-size: .72rem; color: var(--muted); margin-top: 5px; }

/* Topic map --------------------------------------------------------------- */
.module { margin: 26px 0; }
.module h2 { font-size: 1rem; color: var(--accent); text-transform: uppercase; letter-spacing: .08em; margin-bottom: 4px; }
.module .m-sub { color: var(--muted); font-size: .85rem; margin-bottom: 12px; }
.topic-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 12px; }
.topic-card {
  display: flex; gap: 14px; align-items: center; color: var(--text);
  background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 14px 16px;
}
.topic-card:hover { text-decoration: none; border-color: var(--accent); transform: translateY(-2px); }
.topic-card .t-icon { font-size: 1.5rem; width: 40px; text-align: center; flex-shrink: 0; }
.topic-card .t-body { flex: 1; min-width: 0; }
.topic-card .t-title { font-weight: 700; font-size: .95rem; }
.topic-card .t-meta { color: var(--muted); font-size: .75rem; }
.topic-card .t-status { font-size: 1.2rem; flex-shrink: 0; }
.crumb { color: var(--muted); font-size: .85rem; margin-bottom: 14px; }
.crumb a { color: var(--muted); }

/* Topic (learn) page ------------------------------------------------------ */
.learn-layout { display: grid; grid-template-columns: minmax(0, 1fr); gap: 24px; }
.topic-header h1 { margin: 2px 0 6px; font-size: 1.7rem; }
.topic-meta { display: flex; flex-wrap: wrap; gap: 8px; margin: 10px 0 4px; }
.meta-chip { background: var(--panel); border: 1px solid var(--line); color: var(--muted); border-radius: 99px; padding: 3px 12px; font-size: .75rem; }
.toc { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px 18px; margin: 18px 0; }
.toc h4 { margin: 0 0 8px; font-size: .8rem; color: var(--muted); text-transform: uppercase; letter-spacing: .08em; }
.toc ol { margin: 0; padding-left: 20px; columns: 2; }
.toc a { font-size: .85rem; }
.section { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 24px; margin: 16px 0; }
.section h2 { font-size: 1.15rem; margin: 0 0 10px; color: #fff; border-bottom: 1px solid var(--line); padding-bottom: 8px; }
.section p:first-of-type { margin-top: 0; }
.callout { border-left: 4px solid var(--warn); background: rgba(255, 214, 10, .07); padding: 10px 16px; border-radius: 0 10px 10px 0; margin: 14px 0; }
.keypoints { background: rgba(67, 214, 124, .06); border: 1px solid rgba(67, 214, 124, .3); border-radius: var(--radius); padding: 18px 24px; margin: 18px 0; }
.keypoints h3 { margin-top: 0; color: var(--good); }
.tipbox { background: rgba(247, 37, 133, .06); border: 1px solid rgba(247, 37, 133, .3); border-radius: var(--radius); padding: 18px 24px; margin: 18px 0; }
.tipbox h3 { margin-top: 0; color: #ff7ab8; }
.source-note { color: var(--muted); font-size: .78rem; margin-top: 20px; }

.topic-actions { position: sticky; bottom: 14px; display: flex; gap: 12px; justify-content: flex-end; margin: 22px 0; z-index: 5; }
.btn {
  display: inline-block; border: none; border-radius: 12px; cursor: pointer;
  padding: 12px 22px; font-size: .95rem; font-weight: 700; color: #fff;
  background: linear-gradient(135deg, var(--accent), #3a86ff);
  box-shadow: 0 6px 18px rgba(76, 201, 240, .25); transition: transform .12s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn.secondary { background: var(--panel-2); border: 1px solid var(--line); box-shadow: none; }
.btn:disabled { opacity: .5; cursor: default; transform: none; }

/* Quiz -------------------------------------------------------------------- */
.quiz { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px 26px; margin: 26px 0; }
.quiz h2 { margin-top: 0; }
.q-card { border: 1px solid var(--line); border-radius: 12px; padding: 16px 18px; margin: 14px 0; background: var(--bg-2); }
.q-text { font-weight: 700; margin-bottom: 10px; }
.opt { display: block; width: 100%; text-align: left; margin: 6px 0; padding: 10px 14px; border-radius: 10px; border: 1px solid var(--line); background: var(--panel); color: var(--text); cursor: pointer; font-size: .9rem; transition: border-color .12s ease; }
.opt:hover:not(:disabled) { border-color: var(--accent); }
.opt.correct { border-color: var(--good); background: rgba(67, 214, 124, .12); }
.opt.wrong { border-color: var(--bad); background: rgba(255, 93, 93, .1); }
.opt:disabled { cursor: default; }
.q-explain { display: none; margin-top: 10px; padding: 10px 14px; border-radius: 10px; background: rgba(76, 201, 240, .08); font-size: .85rem; }
.q-explain.show { display: block; }
.q-feedback { font-weight: 700; margin-top: 8px; font-size: .85rem; }
.q-result { text-align: center; padding: 18px; border-radius: 12px; background: var(--bg-2); border: 1px dashed var(--line); margin-top: 16px; }

/* Badges ------------------------------------------------------------------ */
.badge-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 12px; }
.badge { background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 14px; text-align: center; }
.badge.locked { opacity: .38; filter: grayscale(.8); }
.badge .b-icon { font-size: 1.6rem; }
.badge .b-name { font-weight: 700; font-size: .82rem; margin-top: 4px; }
.badge .b-hint { color: var(--muted); font-size: .7rem; }

/* Toasts & celebration ------------------------------------------------------ */
.toast-host { position: fixed; bottom: 22px; left: 22px; z-index: 200; display: flex; flex-direction: column; gap: 8px; }
.toast { opacity: 0; transform: translateY(10px); transition: all .3s ease; background: var(--panel-2); border: 1px solid var(--accent); color: var(--text); border-radius: 10px; padding: 10px 16px; box-shadow: var(--shadow); font-size: .88rem; }
.toast.show { opacity: 1; transform: none; }
.celebrate { position: fixed; inset: 0; z-index: 300; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 12px; background: rgba(5, 8, 20, .6); backdrop-filter: blur(3px); pointer-events: none; }
.celebrate-item { display: flex; align-items: center; gap: 12px; background: var(--panel-2); border: 1px solid var(--accent); border-radius: 14px; padding: 14px 30px; font-size: 1.15rem; font-weight: 800; animation: pop .5s ease both; }
.celebrate-icon { font-size: 1.8rem; }
@keyframes pop { from { transform: scale(.6); opacity: 0; } to { transform: scale(1); opacity: 1; } }
.confetti { position: fixed; inset: 0; z-index: 299; pointer-events: none; }

.pager { display: flex; justify-content: space-between; margin-top: 26px; gap: 12px; }
.pager .btn { font-size: .85rem; padding: 10px 16px; }
.empty { color: var(--muted); text-align: center; padding: 60px 20px; }
.soon-banner { border: 1px dashed var(--line); border-radius: var(--radius); padding: 16px 20px; color: var(--muted); background: var(--panel); margin-bottom: 20px; }

/* Diagrams (per-topic animated figures) ------------------------------------- */
.diagram-card {
  background: var(--bg-2); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 16px 20px 12px; margin: 16px 0;
}
.diagram-card .diagram-art { overflow-x: auto; }
.diagram-card svg { display: block; margin: 0 auto; max-width: 100%; height: auto; color: var(--text); }
.diagram-card figcaption { margin-top: 10px; font-size: .78rem; color: var(--muted); line-height: 1.55; }
.diagram-title { display: block; color: var(--text); font-weight: 700; font-size: .85rem; }
.diagram-ref {
  display: inline-block; margin-left: 8px; padding: 1px 9px; border-radius: 99px; vertical-align: baseline;
  background: var(--panel-2); border: 1px solid var(--line); color: var(--muted);
  font-size: .66rem; white-space: nowrap;
}

/* Authoring palette for diagram SVGs (theme-aware, currentColor-friendly):
   box fill #1a2449 = --panel-2, box/edge stroke #4cc9f0 = --accent, labels #e8ecff = --text */
.d-box { fill: var(--panel-2); stroke: var(--accent); stroke-width: 1.5; }
.d-edge { fill: none; stroke: var(--accent); stroke-width: 1.5; opacity: .5; }
.d-label { fill: var(--text); font-family: inherit; font-size: 11px; font-weight: 600; }

/* Shared animation utilities used by diagram authoring html */
.d-flow { fill: none; stroke: var(--accent); stroke-width: 3; stroke-linecap: round; stroke-dasharray: 6 6; animation: d-flow-dash 1.2s linear infinite; }
@keyframes d-flow-dash { to { stroke-dashoffset: -12; } }
.d-pulse { transform-box: fill-box; transform-origin: center; animation: d-pulse-k 1.6s ease-in-out infinite; }
@keyframes d-pulse-k { 0%, 100% { transform: scale(1); opacity: .95; } 50% { transform: scale(1.25); opacity: .35; } }
.d-float { animation: d-float-k 3s ease-in-out infinite; }
@keyframes d-float-k { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-3px); } }

@media (prefers-reduced-motion: reduce) {
  .d-flow, .d-pulse, .d-float { animation: none; }
}

@media (max-width: 720px) {
  .toc ol { columns: 1; }
  .hdr-inner { flex-wrap: wrap; }
  .xp-track { width: 90px; }
}