:root{
  --bg:#fff8ef; --bg2:#fff; --ink:#2b2350; --muted:#6f6893; --line:#ece4d6;
  --pri:#6c4cf5; --pri2:#8f76ff; --pink:#ff5d8f; --yel:#ffc23d; --grn:#22c38e; --red:#ff5a5a; --sky:#35b6ff;
  --wood:#8a5a2b; --wood2:#b07a42; --rod:#d9c3a0; --bead:#ff7a45; --bead2:#ff9f6b; --beadUp:#6c4cf5;
  --card:#ffffff; --shadow:0 8px 24px rgba(60,40,120,.10); --r:20px;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --bg:#17132b; --bg2:#201a3a; --ink:#f3efff; --muted:#a69fca; --line:#322a55; --card:#241d44; --rod:#6b5a83;
  --shadow:0 8px 24px rgba(0,0,0,.35);
}}
*{box-sizing:border-box}
html,body{margin:0}
body{font-family:Nunito,system-ui,sans-serif;background:var(--bg);color:var(--ink);min-height:100vh;
  background-image:radial-gradient(circle at 10% 10%,rgba(255,194,61,.18),transparent 30%),radial-gradient(circle at 90% 20%,rgba(108,76,245,.14),transparent 30%),radial-gradient(circle at 50% 100%,rgba(255,93,143,.12),transparent 35%);background-attachment:fixed}
h1,h2,h3,.brand,.big{font-family:"Baloo 2",Nunito,sans-serif;line-height:1.1;margin:0 0 .4em}
h1{font-size:clamp(2rem,5vw,3.4rem)} h2{font-size:clamp(1.5rem,3.5vw,2.2rem)} h3{font-size:1.25rem}
p{line-height:1.55}
button{font:inherit;cursor:pointer;color:inherit}
.muted{color:var(--muted)}

/* top bar */
.topbar{position:sticky;top:0;z-index:20;display:flex;align-items:center;gap:12px;padding:10px 20px;background:color-mix(in srgb,var(--bg2) 88%,transparent);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.brand{font-size:1.6rem;display:flex;align-items:center;gap:6px;cursor:pointer;margin:0;white-space:nowrap}
.brand b{color:var(--pri)} .logo{font-size:1.7rem}
.nav{display:flex;gap:4px;margin:0 auto;flex-wrap:wrap;justify-content:center}
.nav button{border:0;background:transparent;padding:8px 14px;border-radius:999px;font-weight:800;color:var(--muted)}
.nav button:hover{background:var(--line)}
.nav button.on{background:var(--pri);color:#fff}
.hud{display:flex;gap:6px;align-items:center}
.chip{display:inline-flex;align-items:center;gap:4px;background:var(--card);border:1px solid var(--line);border-radius:999px;padding:5px 10px;font-weight:800;font-size:.9rem}
.chip.icon{cursor:pointer}
.lvl{position:relative;overflow:hidden}
.lvl i{position:absolute;left:0;bottom:0;height:3px;width:100%;background:var(--line)}
.lvl em{display:block;height:100%;background:var(--grn);width:0;transition:width .5s}
@media(max-width:880px){.nav button span{display:none}.topbar{flex-wrap:wrap;padding:8px 12px}.nav{order:3;width:100%}.hud{margin-left:auto}}

main{max-width:1180px;margin:0 auto;padding:24px 16px 80px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);box-shadow:var(--shadow);padding:22px}
.grid{display:grid;gap:18px}
.g2{grid-template-columns:repeat(auto-fit,minmax(300px,1fr))}
.g3{grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}
.g4{grid-template-columns:repeat(auto-fit,minmax(200px,1fr))}
.btn{border:0;border-radius:14px;padding:12px 22px;font-weight:800;font-size:1.05rem;background:var(--pri);color:#fff;box-shadow:0 4px 0 #4a30c9;transition:transform .08s}
.btn:active{transform:translateY(3px);box-shadow:0 1px 0 #4a30c9}
.btn.alt{background:var(--card);color:var(--ink);border:2px solid var(--line);box-shadow:0 4px 0 var(--line)}
.btn.pink{background:var(--pink);box-shadow:0 4px 0 #d23c6c}
.btn.grn{background:var(--grn);box-shadow:0 4px 0 #129a6e}
.btn.yel{background:var(--yel);color:#3a2a00;box-shadow:0 4px 0 #d39a12}
.btn.sm{padding:8px 14px;font-size:.92rem;border-radius:11px}
.btn:disabled{opacity:.45;cursor:not-allowed}
.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.spacer{flex:1}

/* hero */
.hero{display:grid;grid-template-columns:1.1fr 1fr;gap:30px;align-items:center;padding:20px 0 30px}
@media(max-width:860px){.hero{grid-template-columns:1fr}}
.hero h1 span{color:var(--pri)}
.hero .lead{font-size:1.15rem;color:var(--muted);max-width:52ch}
.badge-pill{display:inline-block;background:#ffe7a6;color:#6b4a00;padding:5px 12px;border-radius:999px;font-weight:800;font-size:.85rem;margin-bottom:12px}
.stats{display:flex;gap:26px;margin-top:22px;flex-wrap:wrap}
.stats div b{display:block;font-family:"Baloo 2";font-size:1.8rem;color:var(--pri)}
.feature{cursor:pointer;transition:transform .15s}
.feature:hover{transform:translateY(-4px)}
.feature .ico{font-size:2.2rem;width:58px;height:58px;display:grid;place-items:center;border-radius:16px;margin-bottom:10px}
.section-title{margin:38px 0 14px;display:flex;align-items:end;gap:10px}

/* abacus */
.abacus-wrap{display:flex;flex-direction:column;align-items:center;gap:10px;width:100%}
.abacus{position:relative;background:linear-gradient(180deg,var(--wood2),var(--wood));padding:14px;border-radius:18px;box-shadow:0 10px 0 #5b3a19,0 18px 30px rgba(0,0,0,.2);user-select:none;max-width:100%;overflow-x:auto}
.abacus-inner{display:flex;background:#fdf3e1;border-radius:8px;position:relative}
.rod{position:relative;width:58px;display:flex;flex-direction:column;align-items:center}
.rod::before{content:"";position:absolute;top:0;bottom:0;left:50%;width:5px;margin-left:-2.5px;background:var(--rod);border-radius:3px}
.heaven,.earth{position:relative;width:100%;display:flex;flex-direction:column;align-items:center}
.heaven{height:88px;justify-content:flex-start;padding-top:6px}
.earth{height:200px;justify-content:flex-end;padding-bottom:6px}
.beam{height:14px;width:100%;background:linear-gradient(180deg,#6b4220,#4a2c12);position:relative;z-index:2}
.rod.unit .beam::after{content:"";position:absolute;left:50%;top:50%;width:6px;height:6px;margin:-3px;border-radius:50%;background:#fff}
.bead{width:50px;height:34px;border-radius:50%;background:radial-gradient(ellipse at 35% 30%,var(--bead2),var(--bead) 60%,#c64a17);box-shadow:inset 0 -4px 6px rgba(0,0,0,.2),0 2px 3px rgba(0,0,0,.25);position:relative;z-index:1;cursor:pointer;transition:transform .18s cubic-bezier(.3,1.5,.6,1),filter .2s;margin:2px 0;border:0;padding:0}
.bead.on{background:radial-gradient(ellipse at 35% 30%,#b3a2ff,var(--beadUp) 60%,#3b22a8)}
.bead:hover{filter:brightness(1.1)}
.heaven .bead.on{transform:translateY(42px)}
.earth .bead.on{transform:translateY(-58px)}
.rod-val{height:28px;display:grid;place-items:center;font-family:"Baloo 2";font-weight:800;font-size:1.2rem;color:var(--pri);background:var(--card);width:100%;border-top:1px solid var(--line)}
.rod-label{font-size:.68rem;color:var(--muted);text-align:center;padding:2px 0;font-weight:800;background:var(--card);width:100%}
.rod.hl::after{content:"";position:absolute;inset:-2px;border:3px dashed var(--yel);border-radius:10px;pointer-events:none;z-index:3;animation:pulse 1s infinite}
@keyframes pulse{50%{opacity:.35}}
.abacus.small .rod{width:44px}.abacus.small .bead{width:38px;height:26px}.abacus.small .heaven{height:68px}.abacus.small .earth{height:150px}
.abacus.small .heaven .bead.on{transform:translateY(32px)}.abacus.small .earth .bead.on{transform:translateY(-44px)}
@media(max-width:600px){.rod{width:44px}.bead{width:38px;height:26px}.heaven{height:68px}.earth{height:150px}.heaven .bead.on{transform:translateY(32px)}.earth .bead.on{transform:translateY(-44px)}}
.readout{font-family:"Baloo 2";font-size:3rem;font-weight:800;color:var(--pri);letter-spacing:2px}

/* lessons */
.level-band{margin:26px 0 10px;display:flex;align-items:center;gap:10px}
.level-band .tag{padding:4px 12px;border-radius:999px;font-weight:800;color:#fff;font-size:.85rem}
.lesson{display:flex;gap:14px;align-items:center;cursor:pointer;transition:transform .15s;position:relative}
.lesson:hover{transform:translateY(-3px)}
.lesson .num{width:48px;height:48px;flex:none;border-radius:14px;display:grid;place-items:center;font-family:"Baloo 2";font-weight:800;font-size:1.3rem;color:#fff}
.lesson.locked{opacity:.5;cursor:not-allowed}
.lesson .done{position:absolute;top:10px;right:12px}
.lesson small{color:var(--muted)}
.lesson-view{display:grid;grid-template-columns:1fr 1.2fr;gap:24px;align-items:start}
@media(max-width:900px){.lesson-view{grid-template-columns:1fr}}
.steps-dots{display:flex;gap:6px;margin:8px 0 14px}
.steps-dots i{width:28px;height:8px;border-radius:5px;background:var(--line)}
.steps-dots i.on{background:var(--pri)}
.tip{background:#fff3c9;color:#5a4300;border-radius:14px;padding:12px 14px;font-weight:600;margin:12px 0}
.task{background:color-mix(in srgb,var(--pri) 12%,transparent);border:2px dashed var(--pri);border-radius:14px;padding:12px 14px;font-weight:800;margin:12px 0}
.formula{font-family:"Baloo 2";font-size:1.4rem;background:var(--bg);border-radius:12px;padding:8px 14px;display:inline-block;margin:4px 0}

/* practice / quiz */
.quiz{text-align:center}
.q-text{font-family:"Baloo 2";font-size:clamp(2.4rem,7vw,4.5rem);font-weight:800;margin:10px 0}
.answer-in{font-family:"Baloo 2";font-size:2rem;width:200px;text-align:center;border:3px solid var(--line);border-radius:16px;padding:6px;background:var(--bg);color:var(--ink)}
.answer-in:focus{outline:none;border-color:var(--pri)}
.keypad{display:grid;grid-template-columns:repeat(3,72px);gap:8px;justify-content:center;margin:14px auto}
.keypad button{height:58px;border-radius:14px;border:2px solid var(--line);background:var(--card);font-family:"Baloo 2";font-size:1.6rem;font-weight:800;box-shadow:0 3px 0 var(--line)}
.keypad button:active{transform:translateY(2px);box-shadow:none}
.opts{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;max-width:440px;margin:16px auto}
.opts button{padding:18px;font-family:"Baloo 2";font-size:1.8rem;font-weight:800;border-radius:16px;border:3px solid var(--line);background:var(--card);box-shadow:0 4px 0 var(--line)}
.opts button.right{background:var(--grn);color:#fff;border-color:var(--grn)}
.opts button.wrong{background:var(--red);color:#fff;border-color:var(--red)}
.feedback{min-height:34px;font-weight:800;font-size:1.2rem}
.feedback.ok{color:var(--grn)}.feedback.bad{color:var(--red)}
.bar{height:12px;background:var(--line);border-radius:8px;overflow:hidden}
.bar>i{display:block;height:100%;background:linear-gradient(90deg,var(--grn),var(--sky));width:0;transition:width .3s}
.timer>i{background:linear-gradient(90deg,var(--yel),var(--pink))}
.seg{display:inline-flex;background:var(--bg);border:1px solid var(--line);border-radius:12px;padding:3px;gap:3px;flex-wrap:wrap}
.seg button{border:0;background:transparent;padding:7px 12px;border-radius:9px;font-weight:800;color:var(--muted)}
.seg button.on{background:var(--card);color:var(--pri);box-shadow:0 2px 6px rgba(0,0,0,.08)}
label.f{font-weight:800;font-size:.85rem;color:var(--muted);display:block;margin:12px 0 6px}

/* flash anzan */
.flash-stage{height:220px;display:grid;place-items:center;font-family:"Baloo 2";font-weight:800;font-size:clamp(4rem,14vw,8rem);color:var(--pri);background:var(--bg);border-radius:20px;border:3px solid var(--line)}
.flash-stage.pop{animation:pop .25s}
@keyframes pop{0%{transform:scale(.7);opacity:0}100%{transform:scale(1);opacity:1}}

/* games */
.game-card{cursor:pointer;overflow:hidden;position:relative;transition:transform .15s}
.game-card:hover{transform:translateY(-4px) rotate(-.5deg)}
.game-card .art{height:110px;border-radius:14px;display:grid;place-items:center;font-size:3.4rem;margin-bottom:12px}
.balloons{position:relative;height:380px;background:linear-gradient(180deg,#bfe9ff,#eaf8ff);border-radius:20px;overflow:hidden;border:3px solid var(--line)}
.balloon{position:absolute;width:76px;height:92px;border-radius:50% 50% 48% 48%;display:grid;place-items:center;color:#fff;font-family:"Baloo 2";font-weight:800;font-size:1.6rem;cursor:pointer;box-shadow:inset -8px -10px 0 rgba(0,0,0,.12);border:0}
.balloon::after{content:"";position:absolute;bottom:-26px;left:50%;width:1px;height:26px;background:#888}
.balloon.popd{animation:popb .25s forwards}
@keyframes popb{to{transform:scale(1.6);opacity:0}}
.mem-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;max-width:640px;margin:0 auto}
.mem{aspect-ratio:3/4;border-radius:14px;border:0;background:linear-gradient(135deg,var(--pri),var(--pink));display:grid;place-items:center;font-family:"Baloo 2";font-weight:800;font-size:1.6rem;color:#fff;transition:transform .3s;padding:4px}
.mem.open,.mem.got{background:var(--card);color:var(--ink);border:3px solid var(--line)}
.mem.got{border-color:var(--grn);opacity:.7}
.mini-abacus{display:flex;gap:2px;justify-content:center;transform:scale(.9)}
.mini-abacus .mr{display:flex;flex-direction:column;align-items:center;gap:1px;position:relative}
.mini-abacus .mr::before{content:"";position:absolute;top:0;bottom:0;width:2px;background:#bba;left:50%;margin-left:-1px}
.mini-abacus .mb{width:16px;height:9px;border-radius:50%;background:#ccc;position:relative}
.mini-abacus .mb.on{background:var(--pri)}
.mini-abacus .mbeam{width:20px;height:3px;background:#5b3a19;margin:3px 0;position:relative}
.race-track{position:relative;height:120px;background:repeating-linear-gradient(90deg,#9be38c 0 40px,#8cd87d 40px 80px);border-radius:16px;margin:14px 0;overflow:hidden;border:3px solid var(--line)}
.lane{position:absolute;left:0;right:0;height:50%;border-bottom:2px dashed rgba(255,255,255,.7)}
.lane:nth-child(2){top:50%;border:0}
.racer{position:absolute;font-size:2.6rem;top:50%;transform:translateY(-50%) scaleX(-1);transition:left .4s;left:2%}
.finish{position:absolute;right:20px;top:0;bottom:0;width:14px;background:repeating-linear-gradient(0deg,#000 0 10px,#fff 10px 20px)}

/* progress */
.badge{display:flex;flex-direction:column;align-items:center;text-align:center;padding:16px 10px;gap:4px}
.badge .b-ico{font-size:2.6rem;filter:grayscale(1);opacity:.35}
.badge.got .b-ico{filter:none;opacity:1}
.badge small{color:var(--muted)}
.heat{display:grid;grid-template-columns:repeat(14,1fr);gap:4px}
.heat i{aspect-ratio:1;border-radius:4px;background:var(--line)}
.kpi b{font-family:"Baloo 2";font-size:2rem;color:var(--pri);display:block}
.avatar-pick{display:flex;gap:8px;flex-wrap:wrap}
.avatar-pick button{font-size:1.8rem;width:52px;height:52px;border-radius:14px;border:3px solid var(--line);background:var(--card)}
.avatar-pick button.on{border-color:var(--pri)}
input.txt{font:inherit;padding:10px 12px;border-radius:12px;border:2px solid var(--line);background:var(--bg);color:var(--ink);width:100%}

/* modal/toast */
.modal{position:fixed;inset:0;background:rgba(20,10,50,.55);display:grid;place-items:center;z-index:50;padding:16px}
.modal.hidden{display:none}
.modal-card{background:var(--card);border-radius:24px;padding:28px;max-width:440px;width:100%;text-align:center;animation:pop .3s}
.modal-card .big-emoji{font-size:4rem}
#toast{position:fixed;bottom:22px;left:50%;transform:translateX(-50%) translateY(120px);background:var(--ink);color:var(--bg);padding:12px 20px;border-radius:14px;font-weight:800;z-index:60;transition:transform .3s;max-width:90vw}
#toast.show{transform:translateX(-50%) translateY(0)}
#confetti{position:fixed;inset:0;pointer-events:none;z-index:70}
.mascot{font-size:3rem;display:inline-block;animation:bob 2s ease-in-out infinite}
@keyframes bob{50%{transform:translateY(-6px)}}
.shake{animation:shake .35s}
@keyframes shake{25%{transform:translateX(-8px)}75%{transform:translateX(8px)}}
footer{text-align:center;color:var(--muted);padding:30px;font-size:.9rem}
.rod>*{flex:none}
.rod-val,.rod-label{position:relative;z-index:2}
.tagline{font-family:"Baloo 2",sans-serif;font-weight:800;font-size:1.35rem;color:var(--pink);margin:0 0 8px}
.brand img.logo{width:38px;height:38px;display:block}.brand b{color:var(--pink)}.brand b.o{color:var(--yel);position:relative;top:-3px}.brand b.p{color:var(--grn)}

body.signed-out .nav,body.signed-out .hud{display:none}
.user-chip{padding:2px;width:34px;height:34px;justify-content:center;overflow:hidden}
.user-chip img{width:28px;height:28px;border-radius:50%;display:block}
.login{min-height:calc(100vh - 160px);display:grid;grid-template-columns:minmax(0,440px) minmax(0,1fr);gap:28px;align-items:center}
.login-card{text-align:center;padding:36px 28px}
.login-card h1{font-size:3rem;margin:10px 0 0}
.gbtn{display:flex;justify-content:center;min-height:44px;margin:22px 0 6px}
.small{font-size:.85rem}
.login-art{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.login-art .card{display:flex;flex-direction:column;align-items:center;gap:8px;padding:30px 12px;font-size:1.1rem}
.login-art span{font-size:2.6rem}
@media(max-width:820px){.login{grid-template-columns:1fr}}