:root{
  --bg:#f8fafc;--card:#ffffff;--text:#0f172a;--muted:#64748b;--line:#e2e8f0;
  --brand:#2563eb;--brand-dark:#1d4ed8;--ok:#16a34a;--ok-bg:#dcfce7;--bad:#dc2626;--bad-bg:#fee2e2;
  --gold:#f59e0b;--heart:#ef4444;--radius:18px;--shadow:0 1px 2px rgba(15,23,42,.06),0 4px 14px rgba(15,23,42,.06);
}
@media (prefers-color-scheme:dark){:root:not([data-theme=light]){
  --bg:#0b1220;--card:#131c2e;--text:#e5e7eb;--muted:#94a3b8;--line:#243047;
  --ok-bg:#14532d;--bad-bg:#7f1d1d;--shadow:0 1px 2px rgba(0,0,0,.4);
}}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;padding:0;background:var(--bg);color:var(--text);font:16px/1.45 -apple-system,BlinkMacSystemFont,"Segoe UI",Inter,Roboto,sans-serif}
button{font:inherit;color:inherit;cursor:pointer;border:0;background:none}
#app{max-width:560px;margin:0 auto;min-height:100vh;padding-bottom:calc(96px + env(safe-area-inset-bottom))}
.hidden{display:none!important}

/* top bar */
.topbar{position:sticky;top:0;z-index:5;background:var(--bg);display:flex;align-items:center;justify-content:space-between;padding:calc(10px + env(safe-area-inset-top)) 16px 10px;border-bottom:1px solid var(--line)}
.stat{display:flex;align-items:center;gap:5px;font-weight:700;font-size:15px}
.stat small{font-weight:600;color:var(--muted)}
.brand{font-weight:800;letter-spacing:-.3px}
.iconbtn{width:40px;height:40px;border-radius:12px;display:grid;place-items:center;font-size:20px}
.iconbtn:active{background:var(--line)}

/* home */
.hero{padding:18px 16px 6px}
.hero h1{margin:0 0 4px;font-size:24px;letter-spacing:-.4px}
.hero p{margin:0;color:var(--muted)}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px;margin:12px 16px}
.card h3{margin:0 0 6px;font-size:16px}
.card p{margin:0;color:var(--muted);font-size:14px}
.row{display:flex;align-items:center;gap:12px}
.grow{flex:1}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:14px 20px;border-radius:16px;font-weight:800;font-size:16px;background:var(--brand);color:#fff;box-shadow:0 4px 0 var(--brand-dark);transition:transform .05s}
.btn:active{transform:translateY(3px);box-shadow:0 1px 0 var(--brand-dark)}
.btn.full{width:100%}
.btn.ghost{background:var(--card);color:var(--text);border:2px solid var(--line);box-shadow:0 4px 0 var(--line)}
.btn.ok{background:var(--ok);box-shadow:0 4px 0 #15803d}
.btn.bad{background:var(--bad);box-shadow:0 4px 0 #991b1b}
.btn:disabled{opacity:.45;box-shadow:none;transform:none;cursor:default}
.btn.small{padding:9px 14px;font-size:14px;border-radius:12px}

.world{margin:22px 0 6px}
.world-head{position:sticky;top:61px;z-index:4;margin:0 16px 10px;padding:12px 16px;border-radius:16px;color:#fff;display:flex;align-items:center;gap:12px}
.world-head .icon{font-size:26px}
.world-head h2{margin:0;font-size:17px}
.world-head p{margin:0;font-size:13px;opacity:.9}
.world-head .pct{margin-left:auto;font-weight:800;font-size:13px;background:rgba(255,255,255,.2);padding:4px 8px;border-radius:999px}
.path{display:flex;flex-direction:column;align-items:center;gap:6px;padding:34px 0 10px}
.node{width:100%;display:flex;justify-content:center}
.node button{width:78px;height:78px;border-radius:50%;display:grid;place-items:center;font-size:30px;background:var(--card);border:3px solid var(--line);box-shadow:0 6px 0 var(--line);position:relative;transition:transform .05s}
.node button:active{transform:translateY(4px);box-shadow:0 2px 0 var(--line)}
.node.done button{background:var(--gold);border-color:#d97706;box-shadow:0 6px 0 #b45309;color:#fff}
.node.current button{background:var(--wc);border-color:var(--wc);box-shadow:0 6px 0 rgba(0,0,0,.25);color:#fff;animation:pulse 1.6s infinite}
.node.locked button{opacity:.5}
.node.boss button{width:92px;height:92px;font-size:38px;border-radius:28px}
.node .label{font-size:13px;font-weight:700;margin-top:8px;text-align:center;max-width:180px}
.node .sub{font-size:12px;color:var(--muted);text-align:center}
.node .wrap{display:flex;flex-direction:column;align-items:center}
.node:nth-child(odd) .wrap{transform:translateX(-46px)}
.node:nth-child(even) .wrap{transform:translateX(46px)}
.start-tip{position:absolute;top:-36px;left:50%;transform:translateX(-50%);background:var(--card);color:var(--text);border:2px solid var(--line);border-radius:10px;padding:4px 10px;font-size:12px;font-weight:800;white-space:nowrap;animation:bob 1.2s infinite}
.start-tip:after{content:"";position:absolute;left:50%;bottom:-7px;width:10px;height:10px;background:var(--card);border-right:2px solid var(--line);border-bottom:2px solid var(--line);transform:translateX(-50%) rotate(45deg)}
@keyframes bob{0%,100%{transform:translate(-50%,0)}50%{transform:translate(-50%,-4px)}}
@keyframes pulse{0%,100%{box-shadow:0 6px 0 rgba(0,0,0,.25),0 0 0 0 rgba(37,99,235,.35)}50%{box-shadow:0 6px 0 rgba(0,0,0,.25),0 0 0 12px rgba(37,99,235,0)}}
.locked-world{opacity:.55;filter:grayscale(.4)}

/* bottom nav */
.nav{position:fixed;bottom:0;left:0;right:0;max-width:560px;margin:0 auto;z-index:6;background:var(--card);border-top:1px solid var(--line);display:flex;justify-content:space-around;padding:8px 0 calc(8px + env(safe-area-inset-bottom))}
.nav button{display:flex;flex-direction:column;align-items:center;gap:2px;font-size:11px;font-weight:700;color:var(--muted);padding:4px 14px;border-radius:12px}
.nav button .i{font-size:22px}
.nav button.on{color:var(--brand)}

/* lesson */
.lesson-top{display:flex;align-items:center;gap:12px;padding:calc(12px + env(safe-area-inset-top)) 16px 8px;position:sticky;top:0;background:var(--bg);z-index:5}
.progress{flex:1;height:14px;background:var(--line);border-radius:999px;overflow:hidden}
.progress > div{height:100%;background:var(--ok);border-radius:999px;transition:width .3s}
.hearts{font-weight:800;color:var(--heart);display:flex;align-items:center;gap:4px}
.screen{padding:10px 16px 20px}
.prompt{font-size:21px;font-weight:800;letter-spacing:-.3px;margin:8px 0 16px;line-height:1.3}
.type-tag{display:inline-block;font-size:12px;font-weight:800;color:var(--muted);text-transform:uppercase;letter-spacing:.6px;margin-bottom:6px}

.bubble{display:flex;gap:12px;align-items:flex-start;margin:6px 0 16px}
.avatar{width:52px;height:52px;border-radius:50%;background:var(--card);border:2px solid var(--line);display:grid;place-items:center;font-size:26px;flex:none}
.speech{background:var(--card);border:2px solid var(--line);border-radius:18px;border-top-left-radius:4px;padding:12px 14px;flex:1}
.speech .who{font-size:12px;font-weight:800;color:var(--muted);margin-bottom:3px}
.speech .line{font-size:17px;font-weight:600}
.speech .play{margin-top:8px;font-size:13px;font-weight:800;color:var(--brand)}

.options{display:flex;flex-direction:column;gap:10px}
.opt{text-align:left;padding:14px 16px;border-radius:16px;background:var(--card);border:2px solid var(--line);box-shadow:0 3px 0 var(--line);font-weight:600;font-size:16px;line-height:1.35;transition:transform .05s}
.opt:active{transform:translateY(2px);box-shadow:0 1px 0 var(--line)}
.opt.sel{border-color:var(--brand);background:rgba(37,99,235,.08);box-shadow:0 3px 0 var(--brand)}
.opt.right{border-color:var(--ok);background:var(--ok-bg);box-shadow:0 3px 0 var(--ok)}
.opt.wrong{border-color:var(--bad);background:var(--bad-bg);box-shadow:0 3px 0 var(--bad)}
.opt .k{display:inline-grid;place-items:center;width:26px;height:26px;border-radius:8px;border:2px solid var(--line);font-size:12px;font-weight:800;color:var(--muted);margin-right:10px;vertical-align:middle}

/* swipe */
.deck{position:relative;height:300px;margin:4px 0 14px;transition:height .3s,margin .3s}
.deck.done{height:0;margin:0}
.sw-btns.done{display:none}
.sw-result.done{font-size:15px;color:var(--text);line-height:1.5}
.sw-result.done div{padding:10px 12px;margin-top:8px;border-radius:12px;background:var(--card);border:1px solid var(--line)}
.sw-card{position:absolute;inset:0;background:var(--card);border:2px solid var(--line);border-radius:22px;box-shadow:var(--shadow);display:grid;place-items:center;padding:24px;text-align:center;font-size:19px;font-weight:700;line-height:1.35;transition:transform .25s,opacity .25s;user-select:none;touch-action:pan-y}
.sw-card.out-left{transform:translateX(-120%) rotate(-12deg);opacity:0}
.sw-card.out-right{transform:translateX(120%) rotate(12deg);opacity:0}
.sw-card .stamp{position:absolute;top:14px;padding:4px 10px;border-radius:8px;font-size:13px;font-weight:900;letter-spacing:1px;opacity:0;transition:opacity .15s}
.sw-card .stamp.l{left:14px;color:var(--bad);border:2px solid var(--bad);transform:rotate(-10deg)}
.sw-card .stamp.r{right:14px;color:var(--ok);border:2px solid var(--ok);transform:rotate(10deg)}
.sw-btns{display:flex;gap:12px}
.sw-btns .btn{flex:1}
.sw-count{text-align:center;color:var(--muted);font-size:13px;font-weight:700;margin-bottom:8px}
.sw-result{font-size:13px;color:var(--muted);margin-top:8px}

/* order */
.slots{min-height:60px;display:flex;flex-direction:column;gap:8px;margin-bottom:14px;padding:10px;border:2px dashed var(--line);border-radius:16px}
.slots .empty{color:var(--muted);font-size:14px;text-align:center;padding:10px}
.chip{display:inline-flex;align-items:center;gap:8px;padding:10px 14px;border-radius:14px;background:var(--card);border:2px solid var(--line);box-shadow:0 3px 0 var(--line);font-weight:600;font-size:15px;text-align:left}
.chip .n{display:inline-grid;place-items:center;width:24px;height:24px;border-radius:50%;background:var(--brand);color:#fff;font-size:12px;font-weight:800;flex:none}
.pool{display:flex;flex-wrap:wrap;gap:8px}
.pool .chip.used{opacity:.3;pointer-events:none}
.slots .chip.right{border-color:var(--ok);background:var(--ok-bg)}
.slots .chip.wrong{border-color:var(--bad);background:var(--bad-bg)}

/* fill */
.blank{display:inline-block;min-width:90px;border-bottom:3px solid var(--brand);padding:0 6px;font-weight:800;color:var(--brand)}

/* slider */
.slider-wrap{padding:10px 4px}
.slider-val{text-align:center;font-size:40px;font-weight:900;color:var(--brand);margin:6px 0 12px}
.slider-val small{font-size:16px;color:var(--muted);font-weight:700}
input[type=range]{width:100%;accent-color:var(--brand);height:36px}

/* free */
textarea{width:100%;min-height:120px;padding:14px;border-radius:16px;border:2px solid var(--line);background:var(--card);color:var(--text);font:inherit;font-size:16px;resize:vertical}
.mic{margin-top:8px;display:flex;gap:8px;align-items:center}
.model-ans{margin-top:10px;font-size:14px;background:var(--card);border:2px solid var(--line);border-radius:14px;padding:12px}
.model-ans b{display:block;font-size:12px;color:var(--muted);text-transform:uppercase;letter-spacing:.5px;margin-bottom:4px}

/* footer bar / feedback */
.foot{position:fixed;left:0;right:0;bottom:0;z-index:7;padding:14px 16px calc(14px + env(safe-area-inset-bottom));background:var(--card);border-top:2px solid var(--line)}
.foot .inner{max-width:560px;margin:0 auto}
.foot.ok{background:var(--ok-bg);border-color:var(--ok)}
.foot.bad{background:var(--bad-bg);border-color:var(--bad)}
.fb-title{font-weight:900;font-size:19px;margin-bottom:4px;display:flex;align-items:center;gap:8px}
.foot.ok .fb-title{color:var(--ok)}.foot.bad .fb-title{color:var(--bad)}
.fb-text{font-size:15px;margin-bottom:12px}
.fb-audio{font-size:13px;font-weight:800;color:inherit;opacity:.8;margin-bottom:10px;display:inline-flex;gap:6px}

/* briefing */
.brief{padding:16px}
.brief .big{font-size:72px;text-align:center;margin:20px 0 6px}
.brief h2{text-align:center;margin:0 0 4px;font-size:24px}
.brief .meta{text-align:center;color:var(--muted);margin-bottom:18px;font-weight:600}
.playbar{display:flex;align-items:center;gap:14px;background:var(--card);border:2px solid var(--line);border-radius:20px;padding:14px 16px;margin:10px 0}
.playbtn{width:56px;height:56px;border-radius:50%;background:var(--brand);color:#fff;display:grid;place-items:center;font-size:24px;flex:none;box-shadow:0 4px 0 var(--brand-dark)}
.playbar .t{font-weight:800}
.playbar .s{font-size:13px;color:var(--muted)}
details{margin:8px 0 18px}
summary{cursor:pointer;font-weight:700;color:var(--brand);font-size:14px}
.transcript{font-size:15px;color:var(--muted);padding:10px 2px;line-height:1.55}

/* results */
.result{text-align:center;padding:30px 16px 16px}
.result .big{font-size:80px}
.result h2{margin:8px 0 4px;font-size:26px}
.tiles{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:18px 0}
.tile{background:var(--card);border:2px solid var(--line);border-radius:16px;padding:12px 8px}
.tile .v{font-size:22px;font-weight:900}
.tile .l{font-size:11px;font-weight:800;color:var(--muted);text-transform:uppercase;letter-spacing:.5px}
.badges{display:flex;flex-wrap:wrap;gap:8px;justify-content:center}
.badge{display:inline-flex;align-items:center;gap:6px;padding:6px 10px;border-radius:999px;background:var(--card);border:2px solid var(--line);font-size:13px;font-weight:700}

/* profile */
.comp{display:flex;align-items:center;gap:12px;padding:10px 0;border-bottom:1px solid var(--line)}
.comp:last-child{border:0}
.comp .e{font-size:26px;width:36px;text-align:center}
.comp .n{font-weight:800;font-size:15px}
.comp .d{font-size:13px;color:var(--muted)}
.bar{height:8px;background:var(--line);border-radius:999px;overflow:hidden;margin-top:6px}
.bar > div{height:100%;background:var(--brand)}
.lvl{display:inline-block;padding:3px 10px;border-radius:999px;background:var(--brand);color:#fff;font-weight:800;font-size:12px}
.toggle{display:flex;justify-content:space-between;align-items:center;padding:12px 0;border-bottom:1px solid var(--line)}
.switch{width:46px;height:28px;border-radius:999px;background:var(--line);position:relative;transition:.2s}
.switch:after{content:"";position:absolute;top:3px;left:3px;width:22px;height:22px;border-radius:50%;background:#fff;transition:.2s;box-shadow:0 1px 3px rgba(0,0,0,.3)}
.switch.on{background:var(--ok)}.switch.on:after{left:21px}

.toast{position:fixed;top:calc(70px + env(safe-area-inset-top));left:50%;transform:translateX(-50%);background:var(--text);color:var(--bg);padding:10px 16px;border-radius:12px;font-weight:700;font-size:14px;z-index:20;opacity:0;transition:.25s;pointer-events:none}
.toast.show{opacity:1}
.xp-pop{position:fixed;left:50%;top:40%;transform:translate(-50%,-50%);font-size:34px;font-weight:900;color:var(--gold);z-index:20;animation:xp 1s forwards;pointer-events:none;text-shadow:0 2px 0 rgba(0,0,0,.2)}
@keyframes xp{0%{opacity:0;transform:translate(-50%,0) scale(.6)}30%{opacity:1;transform:translate(-50%,-40px) scale(1.1)}100%{opacity:0;transform:translate(-50%,-120px) scale(1)}}
.shake{animation:shake .4s}
@keyframes shake{0%,100%{transform:translateX(0)}25%{transform:translateX(-6px)}75%{transform:translateX(6px)}}
.muted{color:var(--muted);font-size:13px}
.center{text-align:center}

/* start tip above the current unit */
.start-tip{position:absolute;top:-34px;left:50%;transform:translateX(-50%);background:var(--text);color:var(--bg);font-size:11px;font-weight:900;letter-spacing:1px;padding:5px 11px;border-radius:999px;white-space:nowrap;box-shadow:0 2px 8px rgba(0,0,0,.25);z-index:2;animation:bob 1.4s ease-in-out infinite}
.start-tip:after{content:"";position:absolute;left:50%;bottom:-5px;transform:translateX(-50%);border:5px solid transparent;border-top-color:var(--text);border-bottom:0}
@keyframes bob{0%,100%{transform:translate(-50%,0)}50%{transform:translate(-50%,-3px)}}
/* glossary */
.term{border-bottom:2px dotted var(--brand);cursor:pointer;color:inherit}
.sheet{position:fixed;inset:0;background:rgba(0,0,0,.45);z-index:30;display:flex;align-items:flex-end;justify-content:center}
.sheet .box{background:var(--card);color:var(--text);width:100%;max-width:560px;border-radius:22px 22px 0 0;padding:20px 20px calc(24px + env(safe-area-inset-bottom))}
.sheet h3{margin:0 0 8px;font-size:18px}.sheet p{margin:0 0 14px;font-size:15px;line-height:1.5}
/* confidence */
.conf{display:flex;gap:8px;margin-bottom:10px}
.conf button{flex:1;padding:8px;border-radius:12px;border:2px solid var(--line);background:var(--card);font-weight:700;font-size:13px;color:var(--muted)}
.conf button.on{border-color:var(--brand);color:var(--brand);background:rgba(37,99,235,.08)}
/* richer feedback */
.foot{max-height:80vh;overflow:auto}
.fb-pick{font-size:14px;margin-bottom:10px;padding:10px 12px;border-radius:12px;background:rgba(0,0,0,.06);line-height:1.45}
.fb-why{font-size:14px;line-height:1.5;margin-bottom:12px}
.fb-why summary{font-weight:800;cursor:pointer;margin-bottom:6px;list-style:none}
.fb-why summary:before{content:"▸ "}.fb-why[open] summary:before{content:"▾ "}
/* welcome */
.welcome{padding:28px 20px 40px;max-width:560px;margin:0 auto}
.welcome .big{font-size:56px;text-align:center}
.welcome h1{font-size:30px;margin:12px 0 10px;text-align:center}
.welcome p{font-size:16px;line-height:1.55;margin:0 0 14px}
.welcome ul{padding-left:20px;margin:0 0 20px}.welcome li{margin-bottom:8px;font-size:15px;line-height:1.5}
/* remember card */
.remember{text-align:left;margin:0 0 14px}.remember ul{margin:8px 0 0;padding-left:18px}.remember li{margin:6px 0;font-size:14px;line-height:1.45;color:var(--text)}