/* Layout idea: one reading column like a workbook page; each activity is a "station" card with a labelled tab. */
:root{
  --paper:#f4f6f1; --card:#ffffff; --ink:#16241f; --muted:#5a6b64;
  --pandan:#0f6b52; --pandan-soft:#d9ece4; --sambal:#c8381f; --kunyit:#e2a312; --line:#cfd8d2;
  --display:"Bricolage Grotesque","Trebuchet MS",sans-serif;
  --body:"Atkinson Hyperlegible","Segoe UI",system-ui,sans-serif;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --paper:#0f1714; --card:#18231f; --ink:#e9f0ec; --muted:#9fb1a9;
    --pandan:#56c9a4; --pandan-soft:#1f3a31; --sambal:#ff7a5e; --kunyit:#f0bd45; --line:#2c3b35;
    color-scheme:dark;
  }
}
:root[data-theme="dark"]{
  --paper:#0f1714; --card:#18231f; --ink:#e9f0ec; --muted:#9fb1a9;
  --pandan:#56c9a4; --pandan-soft:#1f3a31; --sambal:#ff7a5e; --kunyit:#f0bd45; --line:#2c3b35;
  color-scheme:dark;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--body);font-size:18px;line-height:1.6}
.topbar{max-width:720px;margin:0 auto;padding:14px 18px 0;display:flex;justify-content:space-between;align-items:center;gap:12px}
.brand{font-family:var(--display);font-weight:800;font-size:1.15rem;color:var(--ink);text-decoration:none}
.brand b{color:var(--pandan)}
.lang{display:inline-flex;border:1.5px solid var(--line);border-radius:999px;overflow:hidden}
.lang button{background:transparent;color:var(--muted);border:0;padding:5px 14px;font-weight:700;font-size:.85rem}
.lang button[aria-pressed="true"]{background:var(--pandan);color:var(--paper)}
main{max-width:720px;margin:0 auto;padding:22px 18px 64px;display:flex;flex-direction:column;gap:28px}
h1,h2,h3{font-family:var(--display);line-height:1.15;text-wrap:balance;margin:0}
h1{font-size:clamp(2rem,6vw,3rem);font-weight:800}
h2{font-size:1.5rem;font-weight:800}
h3{font-size:1.1rem;font-weight:600}
p{margin:0;max-width:65ch}
.meta{display:flex;flex-wrap:wrap;gap:8px;font-size:.85rem}
.chip{border:1.5px solid var(--line);border-radius:999px;padding:2px 12px;color:var(--muted)}
.chip.free{border-color:var(--pandan);color:var(--pandan);font-weight:700}
header.hero{display:flex;flex-direction:column;gap:14px}
.lede{font-size:1.15rem}
.station{background:var(--card);border:1.5px solid var(--line);border-radius:14px;padding:22px 20px;display:flex;flex-direction:column;gap:16px}
.tab{align-self:flex-start;font-family:var(--display);font-weight:600;font-size:.8rem;letter-spacing:.06em;text-transform:uppercase;background:var(--pandan-soft);color:var(--pandan);padding:3px 10px;border-radius:6px}
.note{font-size:.9rem;color:var(--muted)}
button{font:inherit;cursor:pointer}
.btn{display:inline-block;background:var(--pandan);color:var(--paper);border:0;border-radius:10px;padding:10px 18px;font-weight:700;text-decoration:none}
.btn.ghost{background:transparent;color:var(--pandan);border:1.5px solid var(--pandan)}
.btn.small{padding:6px 12px;font-size:.85rem}
.btn:disabled{opacity:.5;cursor:default}
button:focus-visible,input:focus-visible,a:focus-visible{outline:3px solid var(--kunyit);outline-offset:2px}
.row{display:flex;flex-wrap:wrap;gap:10px;align-items:center}
.row.spread{justify-content:space-between}
.strip{font-family:var(--display);font-size:clamp(1.2rem,4.2vw,1.6rem);font-weight:600;background:var(--paper);border-radius:10px;padding:14px 16px;min-height:3.4em}
.strip .new{color:var(--sambal)}
.strip .blank{display:inline-block;min-width:3.5em;border-bottom:3px dashed var(--muted)}
.strip .cursor{display:inline-block;width:.5em;border-bottom:3px solid var(--sambal);animation:blink 1s steps(2) infinite}
@keyframes blink{50%{opacity:0}}
.bars{display:flex;flex-direction:column;gap:8px}
.bar{display:grid;grid-template-columns:minmax(90px,150px) 1fr 3.2em;gap:10px;align-items:center;font-size:.95rem}
.bar .track{height:14px;background:var(--paper);border-radius:7px;overflow:hidden}
.bar .fill{height:100%;width:0;background:var(--muted);border-radius:7px;transition:width .6s ease}
.bar.top .fill{background:var(--pandan)}
.bar.top .word{font-weight:700;color:var(--pandan)}
.bar .pct{text-align:right;font-variant-numeric:tabular-nums;color:var(--muted)}
.bar.mine .word::after{content:" \2190";color:var(--sambal)}
.choices{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:10px}
.choice{background:var(--card);color:var(--ink);border:1.5px solid var(--line);border-radius:10px;padding:12px;font-weight:700;text-align:center}
.choice:hover:not(:disabled){border-color:var(--pandan)}
.feedback{border-left:4px solid var(--kunyit);padding:4px 0 4px 14px}
.score{font-family:var(--display);font-weight:800;font-size:1.3rem}
.slider{display:grid;grid-template-columns:auto 1fr auto;gap:12px;align-items:center;font-size:.9rem;color:var(--muted)}
input[type=range]{width:100%;accent-color:var(--pandan)}
.samples{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:6px}
.samples li{background:var(--paper);border-radius:8px;padding:8px 12px}
.samples b{color:var(--sambal)}
.three{display:grid;grid-template-columns:repeat(auto-fit,minmax(190px,1fr));gap:12px}
.three div{border-top:4px solid var(--pandan);padding-top:10px;display:flex;flex-direction:column;gap:6px}
.three div:nth-child(2){border-color:var(--sambal)}
.three div:nth-child(3){border-color:var(--kunyit)}
.prompt{background:var(--paper);border-radius:10px;padding:14px;display:flex;flex-direction:column;gap:10px}
.prompt pre{margin:0;white-space:pre-wrap;font-family:ui-monospace,Menlo,Consolas,monospace;font-size:.9rem;line-height:1.5}
a{color:var(--pandan)}
.q{display:flex;flex-direction:column;gap:8px;padding-bottom:14px;border-bottom:1px solid var(--line)}
.q:last-of-type{border-bottom:0}
.q .opts{display:flex;flex-direction:column;gap:6px}
.q .opt{text-align:left;background:var(--card);color:var(--ink);border:1.5px solid var(--line);border-radius:8px;padding:9px 12px}
.q .opt.right{border-color:var(--pandan);background:var(--pandan-soft)}
.q .opt.wrong{border-color:var(--sambal)}
.syllabus{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:8px 18px}
.syllabus li{display:grid;grid-template-columns:2em 1fr;gap:6px;padding:6px 0;border-bottom:1px solid var(--line)}
.syllabus .n{font-family:var(--display);font-weight:800;color:var(--pandan);font-variant-numeric:tabular-nums}
footer{font-size:.85rem;color:var(--muted);display:flex;flex-direction:column;gap:6px}
@media (prefers-reduced-motion: reduce){.bar .fill{transition:none}.strip .cursor{animation:none}html{scroll-behavior:auto}}
/* forms and checkout */
.field{display:flex;flex-direction:column;gap:6px}
.field label{font-weight:700;font-size:.95rem}
input[type=email],input[type=text],input[type=password],input[type=number],select{font:inherit;color:var(--ink);background:var(--paper);border:1.5px solid var(--line);border-radius:10px;padding:10px 12px;width:100%}
.inline{display:grid;grid-template-columns:1fr auto;gap:8px}
.check{display:grid;grid-template-columns:auto 1fr;gap:10px;align-items:start;font-size:.9rem;color:var(--muted)}
.check input{margin-top:5px;width:18px;height:18px;accent-color:var(--pandan)}
.msg{font-weight:700}.msg.ok{color:var(--pandan)}.msg.err{color:var(--sambal)}
.price{font-family:var(--display);font-weight:800;font-size:2.2rem;font-variant-numeric:tabular-nums}
.price s{font-size:1.1rem;color:var(--muted);font-weight:600;margin-left:8px}
.sum{display:grid;grid-template-columns:1fr auto;gap:6px 16px;font-variant-numeric:tabular-nums}
.sum .t{font-weight:800;border-top:1.5px solid var(--line);padding-top:6px}
.pill{display:inline-block;border-radius:999px;padding:2px 12px;font-weight:700;font-size:.85rem;background:var(--pandan-soft);color:var(--pandan)}
.pill.wait{background:transparent;border:1.5px solid var(--kunyit);color:var(--kunyit)}
.ref{font-family:ui-monospace,Menlo,Consolas,monospace;font-size:1.3rem;font-weight:700;letter-spacing:.06em}
.qr{max-width:260px;border-radius:12px;border:1.5px solid var(--line);background:#fff}
ul.plain{margin:0;padding-left:1.2em;display:flex;flex-direction:column;gap:6px}
table{border-collapse:collapse;width:100%;font-size:.85rem}
th,td{text-align:left;padding:6px 8px;border-bottom:1px solid var(--line);vertical-align:top}
.scroll{overflow-x:auto}
/* course index */
ol.index{list-style:none;margin:0 0 8px;padding:0;display:flex;flex-direction:column}
ol.index li{display:grid;grid-template-columns:2em 1fr auto;gap:10px;align-items:start;padding:10px 0;border-bottom:1px solid var(--line)}
ol.index .n{font-family:var(--display);font-weight:800;color:var(--pandan);font-variant-numeric:tabular-nums}
ol.index div{display:flex;flex-direction:column;gap:2px}
/* lesson extras */
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chips button{background:var(--card);color:var(--ink);border:1.5px solid var(--line);border-radius:999px;padding:6px 14px;font-weight:700;font-size:.9rem}
.chips button[aria-pressed="true"]{background:var(--pandan);border-color:var(--pandan);color:var(--paper)}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:12px}
.flip{text-align:left;background:var(--paper);color:var(--ink);border:1.5px solid var(--line);border-radius:12px;padding:14px;display:flex;flex-direction:column;gap:8px;min-height:120px}
.flip .a{color:var(--muted);font-size:.95rem}
.flip[aria-expanded="true"]{border-color:var(--pandan)}
dl.gloss{margin:0;display:grid;grid-template-columns:minmax(110px,auto) 1fr;gap:8px 16px}
dl.gloss dt{font-weight:700;color:var(--pandan)} dl.gloss dd{margin:0}
/* sidebar navigation */
.side{position:fixed;top:0;bottom:0;left:0;width:min(86vw,300px);background:var(--card);border-right:1.5px solid var(--line);padding:16px 14px 28px;overflow-y:auto;z-index:30;transform:translateX(-100%);transition:transform .2s ease;display:flex;flex-direction:column;gap:10px}
.side.open{transform:none}
.side-backdrop{position:fixed;inset:0;background:rgba(0,0,0,.45);z-index:20;display:none}
.side-backdrop.open{display:block}
.side-top{display:flex;justify-content:space-between;align-items:center;gap:8px;padding-bottom:6px}
.side-close,.side-toggle{background:transparent;color:var(--ink);border:1.5px solid var(--line);border-radius:8px;padding:5px 12px;font-weight:700;font-size:.85rem}
.side-course{border-top:1px solid var(--line);padding-top:8px}
.side-course summary{cursor:pointer;display:flex;justify-content:space-between;align-items:center;gap:8px;padding:6px 4px;list-style:none}
.side-course summary::-webkit-details-marker{display:none}
.side-ctitle{font-family:var(--display);font-weight:800}
.side-list{list-style:none;margin:4px 0 0;padding:0;display:flex;flex-direction:column;gap:2px}
.side-link{display:grid;grid-template-columns:1.7em 1fr;gap:6px;padding:7px 8px;border-radius:8px;color:var(--ink);text-decoration:none;font-size:.9rem;line-height:1.35}
a.side-link:hover{background:var(--paper)}
.side-link[aria-current="page"]{background:var(--pandan-soft);color:var(--pandan);font-weight:700}
.side-link.off{color:var(--muted)}
.side-overview{display:block;font-weight:700;color:var(--pandan)}
.side-n{font-variant-numeric:tabular-nums;color:var(--pandan);font-weight:700}
.side-link.off .side-n{color:var(--muted)}
.side-progress{font-size:.8rem;color:var(--muted);padding:0 8px}
.side .note{padding:0 8px;font-size:.85rem}
.topbar{flex-wrap:wrap}
@media (min-width:1040px){
  body.has-side{padding-left:300px}
  .side{transform:none;width:300px}
  .side-toggle,.side-close,.side-backdrop.open{display:none}
}
@media (prefers-reduced-motion: reduce){.side{transition:none}}
/* lesson rating and navigation */
.lesson-extras{display:flex;flex-direction:column;gap:20px}
.stars{display:flex;gap:6px}
.star{background:transparent;border:0;font-size:2.2rem;line-height:1;color:var(--line);padding:2px 4px}
.star.on{color:var(--kunyit)}
.lesson-nav{display:flex;flex-direction:column;gap:14px}
.course-card h2 a{color:var(--ink);text-decoration:none}