:root {
  --bg: #ffffff; --bg2: #f7f7f7; --card: #ffffff; --line: #e5e5e5; --text: #3c3c3c; --muted: #777;
  --green: #58cc02; --green-d: #46a302; --blue: #1cb0f6; --blue-d: #1899d6; --red: #ff4b4b; --red-d: #ea2b2b;
  --gold: #ffc800; --gold-d: #e5a400; --purple: #ce82ff; --orange: #ff9600;
  --ok-bg: #d7ffb8; --ok-text: #58a700; --bad-bg: #ffdfe0; --bad-text: #ea2b2b;
  --radius: 16px;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #131f24; --bg2: #1a2a31; --card: #172329; --line: #37464f; --text: #f1f7fb; --muted: #9fb0b9;
    --ok-bg: #1f3a14; --ok-text: #79d634; --bad-bg: #3d1f22; --bad-text: #ff7b7b;
  }
}
:root[data-theme="dark"] {
  --bg: #131f24; --bg2: #1a2a31; --card: #172329; --line: #37464f; --text: #f1f7fb; --muted: #9fb0b9;
  --ok-bg: #1f3a14; --ok-text: #79d634; --bad-bg: #3d1f22; --bad-text: #ff7b7b;
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body { background: var(--bg); color: var(--text); font-family: 'Nunito', system-ui, sans-serif; font-weight: 700; line-height: 1.45; }
a { color: var(--blue); text-decoration: none; }
h1, h2, h3 { font-weight: 900; margin: 0 0 .5em; line-height: 1.2; }
p { margin: 0 0 .8em; }

/* header */
.top { position: sticky; top: 0; z-index: 10; display: flex; align-items: center; gap: 16px; padding: 10px 20px; background: var(--bg); border-bottom: 2px solid var(--line); }
.logo { font-size: 26px; font-weight: 900; color: var(--green); display: flex; gap: 6px; align-items: center; }
.nav { display: flex; gap: 4px; flex: 1; justify-content: center; }
.nav a { color: var(--muted); padding: 8px 14px; border-radius: 12px; border: 2px solid transparent; font-weight: 800; text-transform: uppercase; font-size: 14px; letter-spacing: .03em; }
.nav a.on { color: var(--blue); background: color-mix(in srgb, var(--blue) 12%, transparent); border-color: color-mix(in srgb, var(--blue) 40%, transparent); }
.nav a:hover { background: var(--bg2); }
.me { display: flex; gap: 12px; color: var(--text); font-weight: 900; align-items: center; white-space: nowrap; }
.me .streak { color: var(--orange); } .me .xp { color: var(--gold-d); }
@media (max-width: 760px) {
  .top { padding: 8px 12px; }
  .nav { position: fixed; bottom: 0; left: 0; right: 0; background: var(--bg); border-top: 2px solid var(--line); justify-content: space-around; padding: 6px 4px; }
  .nav a { display: flex; flex-direction: column; align-items: center; font-size: 11px; padding: 4px 6px; }
  .nav a span { display: block; }
  body { padding-bottom: 70px; }
  .logo span { display: none; }
  .me { margin-left: auto; }
}

main { max-width: 980px; margin: 0 auto; padding: 24px 16px 60px; }
.narrow { max-width: 640px; margin: 0 auto; }
.muted { color: var(--muted); }
.small { font-size: 14px; }
.row { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); }
.card { background: var(--card); border: 2px solid var(--line); border-radius: var(--radius); padding: 18px; }
a.card { color: var(--text); display: block; transition: transform .08s; }
a.card:hover { transform: translateY(-2px); border-color: var(--blue); }
.card .emoji { font-size: 34px; }
.pill { display: inline-block; padding: 2px 10px; border-radius: 99px; background: var(--bg2); border: 2px solid var(--line); font-size: 13px; color: var(--muted); }
.pill.ok { background: var(--ok-bg); color: var(--ok-text); border-color: transparent; }

/* buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; border: 0; cursor: pointer; font: inherit; font-weight: 900; text-transform: uppercase; letter-spacing: .04em;
  padding: 13px 22px; border-radius: 16px; color: #fff; background: var(--green); box-shadow: 0 4px 0 var(--green-d); transition: transform .05s, box-shadow .05s; font-size: 15px; }
.btn:active { transform: translateY(4px); box-shadow: 0 0 0 var(--green-d); }
.btn.blue { background: var(--blue); box-shadow: 0 4px 0 var(--blue-d); }
.btn.red { background: var(--red); box-shadow: 0 4px 0 var(--red-d); }
.btn.gold { background: var(--gold); box-shadow: 0 4px 0 var(--gold-d); color: #5a4300; }
.btn.ghost { background: var(--card); color: var(--blue); border: 2px solid var(--line); box-shadow: 0 4px 0 var(--line); }
.btn.wide { width: 100%; }
.btn:disabled { background: var(--line); box-shadow: 0 4px 0 var(--line); color: var(--muted); cursor: default; transform: none; }
.icon-btn { border: 0; background: var(--blue); color: #fff; width: 44px; height: 44px; border-radius: 14px; font-size: 20px; cursor: pointer; box-shadow: 0 4px 0 var(--blue-d); flex: none; }
.icon-btn.sm { width: 32px; height: 32px; font-size: 15px; border-radius: 10px; box-shadow: 0 3px 0 var(--blue-d); }

/* home */
.hero { display: grid; grid-template-columns: 1.2fr 1fr; gap: 32px; align-items: center; padding: 24px 0 40px; }
.hero h1 { font-size: clamp(32px, 5vw, 52px); color: var(--green); }
.hero .lead { font-size: 20px; color: var(--muted); }
.mascot { font-size: 140px; text-align: center; line-height: 1; filter: drop-shadow(0 8px 0 rgba(0,0,0,.08)); }
@media (max-width: 760px) { .hero { grid-template-columns: 1fr; } .mascot { font-size: 90px; order: -1; } }
.section-title { margin: 36px 0 14px; }
.auth { max-width: 420px; }
.auth input, .field { width: 100%; padding: 14px 16px; border-radius: 14px; border: 2px solid var(--line); background: var(--bg2); color: var(--text); font: inherit; font-size: 17px; margin-bottom: 10px; }
.auth input:focus, .field:focus { outline: none; border-color: var(--blue); }
.tabs { display: flex; gap: 8px; margin-bottom: 14px; }
.tabs button { flex: 1; border: 2px solid var(--line); background: var(--card); color: var(--muted); padding: 10px; border-radius: 12px; font: inherit; font-weight: 900; cursor: pointer; }
.tabs button.on { color: var(--blue); border-color: var(--blue); }
.err { color: var(--red); min-height: 1.4em; }
.steps { counter-reset: s; list-style: none; padding: 0; }
.steps li { counter-increment: s; padding-left: 44px; position: relative; margin-bottom: 12px; }
.steps li::before { content: counter(s); position: absolute; left: 0; top: -2px; width: 30px; height: 30px; border-radius: 50%; background: var(--green); color: #fff; display: grid; place-items: center; font-weight: 900; }

/* learn path */
.sec-head { margin: 34px 0 12px; padding: 14px 18px; border-radius: var(--radius); background: var(--green); color: #fff; box-shadow: 0 4px 0 var(--green-d); }
.sec-head h2 { margin: 0; font-size: 20px; }
.unit { margin: 26px 0; }
.unit-head { display: flex; gap: 14px; align-items: center; margin-bottom: 14px; }
.unit-head .emoji { font-size: 36px; }
.unit-head h3 { margin: 0; }
.path { display: flex; flex-direction: column; align-items: center; gap: 14px; }
.node { width: 72px; height: 66px; border-radius: 50%; border: 0; font-size: 28px; cursor: pointer; display: grid; place-items: center; color: #fff;
  background: var(--line); box-shadow: 0 6px 0 color-mix(in srgb, var(--line) 70%, #000); position: relative; }
.node.done { background: var(--gold); box-shadow: 0 6px 0 var(--gold-d); }
.node.next { background: var(--green); box-shadow: 0 6px 0 var(--green-d); animation: pulse 1.6s infinite; }
.node.extra { background: var(--blue); box-shadow: 0 6px 0 var(--blue-d); width: 60px; height: 56px; font-size: 24px; }
.node:active { transform: translateY(5px); box-shadow: none; }
.node-wrap { display: flex; align-items: center; gap: 12px; }
.node-label { font-size: 14px; color: var(--muted); width: 150px; }
.node-wrap:nth-child(4n+1) { transform: translateX(-60px); } .node-wrap:nth-child(4n+2) { transform: translateX(0); }
.node-wrap:nth-child(4n+3) { transform: translateX(60px); } .node-wrap:nth-child(4n) { transform: translateX(0); }
@media (max-width: 480px) { .node-wrap { transform: none !important; } }
@keyframes pulse { 0%,100% { outline: 0 solid color-mix(in srgb, var(--green) 40%, transparent); } 50% { outline: 8px solid color-mix(in srgb, var(--green) 25%, transparent); } }

/* player */
.player { max-width: 720px; margin: 0 auto; min-height: calc(100vh - 160px); display: flex; flex-direction: column; }
.player-top { display: flex; gap: 14px; align-items: center; margin-bottom: 26px; }
.close { background: none; border: 0; font-size: 26px; color: var(--muted); cursor: pointer; }
.bar { flex: 1; height: 16px; background: var(--line); border-radius: 99px; overflow: hidden; }
.bar > div { height: 100%; background: var(--green); border-radius: 99px; transition: width .3s; }
.timer { font-variant-numeric: tabular-nums; color: var(--muted); }
.ex { flex: 1; }
.ex h2 { font-size: 24px; }
.prompt { font-size: 22px; margin-bottom: 20px; display: flex; gap: 12px; align-items: center; }
.choices { display: grid; gap: 12px; }
.choices.two { grid-template-columns: 1fr 1fr; }
.choice { text-align: left; border: 2px solid var(--line); border-bottom-width: 4px; background: var(--card); color: var(--text); font: inherit; font-size: 18px; padding: 14px 16px; border-radius: 14px; cursor: pointer; display: flex; gap: 12px; align-items: center; }
.choice .k { border: 2px solid var(--line); border-radius: 8px; width: 28px; height: 28px; display: grid; place-items: center; font-size: 14px; color: var(--muted); flex: none; }
.choice:hover { background: var(--bg2); }
.choice.sel { border-color: var(--blue); background: color-mix(in srgb, var(--blue) 12%, var(--card)); color: var(--blue-d); }
.choice.good { border-color: var(--green); background: var(--ok-bg); color: var(--ok-text); }
.choice.badc { border-color: var(--red); background: var(--bad-bg); color: var(--bad-text); }
.choice.gone { opacity: .35; pointer-events: none; }
.answer-input { width: 100%; min-height: 110px; padding: 14px; border: 2px solid var(--line); border-radius: 14px; background: var(--bg2); color: var(--text); font: inherit; font-size: 20px; resize: vertical; }
.answer-input:focus { outline: none; border-color: var(--blue); }
.accents { display: flex; gap: 6px; margin-top: 10px; flex-wrap: wrap; }
.accents button { border: 2px solid var(--line); border-bottom-width: 4px; background: var(--card); color: var(--text); font: inherit; font-size: 18px; padding: 4px 12px; border-radius: 10px; cursor: pointer; }
.build-area { min-height: 64px; border-bottom: 2px solid var(--line); border-top: 2px solid var(--line); padding: 10px 0; display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 24px; }
.bank { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; }
.tile { border: 2px solid var(--line); border-bottom-width: 4px; background: var(--card); color: var(--text); font: inherit; font-size: 18px; padding: 8px 14px; border-radius: 12px; cursor: pointer; }
.tile.used { visibility: hidden; }
.match { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.match .col { display: grid; gap: 12px; }
.feedback { position: sticky; bottom: 0; margin: 20px -16px -60px; padding: 18px 16px 24px; background: var(--bg); border-top: 2px solid var(--line); }
.feedback .in { max-width: 720px; margin: 0 auto; display: flex; gap: 16px; align-items: center; justify-content: space-between; flex-wrap: wrap; }
.feedback.ok { background: var(--ok-bg); color: var(--ok-text); border-color: transparent; }
.feedback.bad { background: var(--bad-bg); color: var(--bad-text); border-color: transparent; }
.feedback h3 { margin: 0 0 4px; font-size: 22px; }
.feedback .btn { min-width: 160px; }
@media (max-width: 760px) { .feedback { margin-bottom: -130px; padding-bottom: 90px; } }
.done-screen { text-align: center; padding-top: 30px; }
.done-screen .big { font-size: 90px; }
.stats { display: flex; gap: 14px; justify-content: center; margin: 24px 0; flex-wrap: wrap; }
.stat { border: 2px solid var(--gold); border-radius: 16px; overflow: hidden; min-width: 130px; }
.stat .h { background: var(--gold); color: #fff; padding: 4px 10px; font-size: 13px; text-transform: uppercase; }
.stat .v { padding: 12px; font-size: 24px; color: var(--gold-d); }
.stat.g { border-color: var(--green); } .stat.g .h { background: var(--green); } .stat.g .v { color: var(--green-d); }
.stat.b { border-color: var(--blue); } .stat.b .h { background: var(--blue); } .stat.b .v { color: var(--blue-d); }
.review-list { text-align: left; margin-top: 20px; }
.review-list .r { border: 2px solid var(--line); border-radius: 12px; padding: 10px 14px; margin-bottom: 8px; }
.review-list .r.wrong { border-color: var(--red); }

/* recap */
.tips { font-weight: 600; }
.tips h3 { margin-top: 1em; font-size: 18px; }
.tips ul { padding-left: 20px; }
.ct { border-collapse: collapse; margin: 10px 0 14px; min-width: 260px; }
.ct td, .ct th { border: 2px solid var(--line); padding: 6px 12px; text-align: left; }
.ct td:first-child { color: var(--muted); }
.vocab { width: 100%; border-collapse: collapse; }
.vocab td { padding: 8px 6px; border-bottom: 2px solid var(--line); vertical-align: middle; }
.vocab td:first-child { width: 40px; }
.vocab .es { font-weight: 900; }
.table-wrap { overflow-x: auto; }

/* flashcards */
.flash { perspective: 1000px; height: 260px; margin: 20px 0; cursor: pointer; }
.flash .inner { position: relative; width: 100%; height: 100%; transition: transform .45s; transform-style: preserve-3d; }
.flash.flip .inner { transform: rotateY(180deg); }
.flash .face { position: absolute; inset: 0; backface-visibility: hidden; display: grid; place-items: center; text-align: center; padding: 20px; border: 2px solid var(--line); border-bottom-width: 6px; border-radius: 20px; background: var(--card); font-size: 30px; font-weight: 900; }
.flash .back { transform: rotateY(180deg); color: var(--blue); }

/* reading */
.reading-text { font-size: 19px; font-weight: 600; line-height: 1.7; }
.reading-text p { margin-bottom: 1em; }
.reading-text .w { cursor: pointer; border-radius: 4px; }
.reading-text .w:hover { background: color-mix(in srgb, var(--blue) 18%, transparent); }
.gloss { display: grid; grid-template-columns: auto 1fr; gap: 4px 14px; font-size: 15px; }
.q { margin: 18px 0; }
.q .choices { margin-top: 8px; }

/* profile */
.lb { width: 100%; border-collapse: collapse; }
.lb td { padding: 10px 8px; border-bottom: 2px solid var(--line); }
.lb tr.me-row td { color: var(--blue); }
.toggle { display: inline-flex; border: 2px solid var(--line); border-radius: 12px; overflow: hidden; }
.toggle button { border: 0; background: var(--card); color: var(--muted); padding: 8px 14px; font: inherit; font-weight: 900; cursor: pointer; }
.toggle button.on { background: var(--blue); color: #fff; }
.banner { background: color-mix(in srgb, var(--gold) 22%, var(--card)); border: 2px solid var(--gold); border-radius: 14px; padding: 10px 14px; margin-bottom: 18px; }
footer.foot { margin-top: 50px; color: var(--muted); font-size: 14px; text-align: center; }