/* Steel Academy — macOS / iOS inspired learning UI
   Layout: macOS source-list sidebar + toolbar on wide screens; iOS large-title nav + tab bar on phones. */
:root{
  --fs:16px;
  --bg:#F5F5F7; --bg2:#FFFFFF; --bg3:#F2F2F7; --elev:#FFFFFF;
  --label:#1D1D1F; --label2:rgba(60,60,67,.72); --label3:rgba(60,60,67,.45);
  --fill:rgba(120,120,128,.12); --fill2:rgba(120,120,128,.08); --sep:rgba(60,60,67,.16);
  --mat:rgba(246,246,248,.72); --mat-side:rgba(236,236,240,.70);
  --tint:#007AFF; --green:#34C759; --orange:#FF9500; --red:#FF3B30; --purple:#AF52DE; --indigo:#5856D6; --teal:#30B0C7; --yellow:#FFCC00; --pink:#FF2D55;
  --shadow:0 1px 2px rgba(0,0,0,.06),0 8px 24px rgba(0,0,0,.06);
  --shadow2:0 12px 40px rgba(0,0,0,.18),0 2px 8px rgba(0,0,0,.08);
  --r1:10px; --r2:14px; --r3:20px;
  --spring:cubic-bezier(.32,.72,0,1); --bounce:cubic-bezier(.34,1.56,.64,1);
  --font:-apple-system,BlinkMacSystemFont,"SF Pro Text","Helvetica Neue","Noto Sans Myanmar","Noto Sans JP","Hiragino Sans",sans-serif;
  --font-jp:"Hiragino Sans","Noto Sans JP","Yu Gothic",sans-serif;
  --font-my:"Noto Sans Myanmar","Myanmar Text","Padauk",sans-serif;
  --side:272px; --tb:52px;
  color-scheme:light;
}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){
  --bg:#000000; --bg2:#1C1C1E; --bg3:#2C2C2E; --elev:#2C2C2E;
  --label:#F5F5F7; --label2:rgba(235,235,245,.68); --label3:rgba(235,235,245,.4);
  --fill:rgba(120,120,128,.28); --fill2:rgba(120,120,128,.18); --sep:rgba(84,84,88,.6);
  --mat:rgba(22,22,24,.72); --mat-side:rgba(28,28,30,.72);
  --tint:#0A84FF; --green:#30D158; --orange:#FF9F0A; --red:#FF453A; --purple:#BF5AF2; --indigo:#5E5CE6; --teal:#40C8E0; --yellow:#FFD60A; --pink:#FF375F;
  --shadow:0 1px 2px rgba(0,0,0,.4),0 8px 24px rgba(0,0,0,.3); --shadow2:0 16px 48px rgba(0,0,0,.6);
  color-scheme:dark}}
:root[data-theme="dark"]{
  --bg:#000000; --bg2:#1C1C1E; --bg3:#2C2C2E; --elev:#2C2C2E;
  --label:#F5F5F7; --label2:rgba(235,235,245,.68); --label3:rgba(235,235,245,.4);
  --fill:rgba(120,120,128,.28); --fill2:rgba(120,120,128,.18); --sep:rgba(84,84,88,.6);
  --mat:rgba(22,22,24,.72); --mat-side:rgba(28,28,30,.72);
  --tint:#0A84FF; --green:#30D158; --orange:#FF9F0A; --red:#FF453A; --purple:#BF5AF2; --indigo:#5E5CE6; --teal:#40C8E0; --yellow:#FFD60A; --pink:#FF375F;
  --shadow:0 1px 2px rgba(0,0,0,.4),0 8px 24px rgba(0,0,0,.3); --shadow2:0 16px 48px rgba(0,0,0,.6);
  color-scheme:dark}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{height:100%}
body{margin:0;background:var(--bg);color:var(--label);font:400 var(--fs)/1.6 var(--font);-webkit-font-smoothing:antialiased;overflow:hidden}
button,input,select,textarea{font:inherit;color:inherit}
a{color:var(--tint);text-decoration:none}
:focus-visible{outline:3px solid color-mix(in srgb,var(--tint) 55%,transparent);outline-offset:2px;border-radius:8px}
.app{display:grid;grid-template-columns:var(--side) 1fr;height:100%;transition:grid-template-columns .45s var(--spring)}
.main{position:relative;display:flex;flex-direction:column;min-width:0;height:100%;background:var(--bg)}

/* ---------- sidebar (macOS source list) ---------- */
.sidebar{background:var(--mat-side);backdrop-filter:saturate(180%) blur(30px);-webkit-backdrop-filter:saturate(180%) blur(30px);border-right:1px solid var(--sep);
  padding:calc(env(safe-area-inset-top,0px) + 14px) 10px 14px;overflow:auto;display:flex;flex-direction:column;gap:2px;z-index:5}
.sb-brand{display:flex;align-items:center;gap:10px;padding:6px 10px 14px}
.sb-brand .logo-tile{width:34px;height:34px;border-radius:9px}
.sb-brand b{display:block;font-size:.95rem;letter-spacing:-.01em}
.sb-brand small{display:block;font-size:.72rem;color:var(--label2);line-height:1.2}
.sb-search{margin:0 4px 10px;position:relative}
.sb-search input{width:100%;border:0;border-radius:8px;background:var(--fill);padding:6px 10px 6px 30px;font-size:.88rem;outline:none;transition:box-shadow .2s}
.sb-search input:focus{box-shadow:0 0 0 3px color-mix(in srgb,var(--tint) 35%,transparent)}
.sb-search svg{position:absolute;left:9px;top:50%;width:14px;height:14px;transform:translateY(-50%);color:var(--label3)}
.sb-h{font-size:.7rem;font-weight:600;color:var(--label3);padding:14px 12px 4px;letter-spacing:.02em}
.sb-i{position:relative;display:flex;align-items:center;gap:10px;padding:6px 10px;border-radius:8px;color:var(--label);font-size:.9rem;line-height:1.35;cursor:pointer;transition:background .2s,transform .2s var(--spring)}
.sb-i:hover{background:var(--fill2)}
.sb-i:active{transform:scale(.98)}
.sb-i .ic{width:22px;height:22px;display:grid;place-items:center;border-radius:6px;color:#fff;flex:none}
.sb-i .ic svg{width:14px;height:14px}
.sb-i .badge{margin-left:auto;font-size:.72rem;color:var(--label2);font-variant-numeric:tabular-nums}
.sb-i.on{background:color-mix(in srgb,var(--tint) 16%,transparent);font-weight:600}
.sb-i.on::before{content:"";position:absolute;inset:0;border-radius:8px;box-shadow:inset 0 0 0 1px color-mix(in srgb,var(--tint) 20%,transparent)}
.sb-foot{margin-top:auto;padding:12px 10px 0;font-size:.74rem;color:var(--label2);display:flex;align-items:center;gap:8px}
.dot{width:8px;height:8px;border-radius:50%;background:var(--label3);flex:none;transition:background .3s}
.dot.ok{background:var(--green);box-shadow:0 0 0 4px color-mix(in srgb,var(--green) 22%,transparent)}
.dot.busy{background:var(--orange);animation:pulse 1s infinite}
@keyframes pulse{50%{opacity:.35}}

/* ---------- toolbar ---------- */
.toolbar{position:sticky;top:0;z-index:4;display:flex;align-items:center;gap:8px;min-height:calc(var(--tb) + env(safe-area-inset-top,0px));padding:env(safe-area-inset-top,0px) max(16px,env(safe-area-inset-right,0px)) 0 max(16px,env(safe-area-inset-left,0px));
  background:var(--mat);backdrop-filter:saturate(180%) blur(24px);-webkit-backdrop-filter:saturate(180%) blur(24px);border-bottom:1px solid transparent;transition:border-color .25s}
.toolbar.scrolled{border-bottom-color:var(--sep)}
.tb-back{display:none;align-items:center;gap:2px;border:0;background:none;color:var(--tint);font-size:1rem;padding:6px 6px 6px 0;cursor:pointer;max-width:40vw;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.tb-back svg{width:22px;height:22px;flex:none}
.tb-back.show{display:inline-flex;animation:fadeIn .3s var(--spring)}
.tb-title{font-weight:600;font-size:1rem;flex:1;min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;opacity:0;transform:translateY(4px);transition:opacity .25s,transform .35s var(--spring)}
.toolbar.scrolled .tb-title,.toolbar.always .tb-title{opacity:1;transform:none}
.tb-act{display:flex;gap:6px;align-items:center}
.icon-btn{width:34px;height:34px;display:grid;place-items:center;border:0;border-radius:9px;background:transparent;color:var(--tint);cursor:pointer;transition:background .2s,transform .25s var(--bounce)}
.icon-btn:hover{background:var(--fill2)}
.icon-btn:active{transform:scale(.88)}
.icon-btn svg{width:20px;height:20px}
.icon-btn.on{color:var(--orange)}

/* segmented control */
.seg{position:relative;display:inline-grid;grid-auto-flow:column;grid-auto-columns:1fr;background:var(--fill);border-radius:9px;padding:2px;isolation:isolate}
.seg button{position:relative;z-index:1;border:0;background:none;padding:4px 12px;font-size:.8rem;font-weight:500;border-radius:7px;cursor:pointer;white-space:nowrap;transition:color .2s}
.seg .knob{position:absolute;z-index:0;top:2px;bottom:2px;left:2px;border-radius:7px;background:var(--elev);box-shadow:0 1px 3px rgba(0,0,0,.12),0 3px 8px rgba(0,0,0,.08);transition:transform .45s var(--spring),width .45s var(--spring)}
.seg button.on{font-weight:600}

/* ---------- view & transitions ---------- */
.view{flex:1;overflow:auto;overscroll-behavior:contain;outline:none;scroll-behavior:auto;-webkit-overflow-scrolling:touch}
.page{max-width:980px;margin:0 auto;padding:8px max(20px,env(safe-area-inset-right,0px)) calc(110px + env(safe-area-inset-bottom,0px)) max(20px,env(safe-area-inset-left,0px))}
.page.wide{max-width:1180px}
.page.read{max-width:860px}
.enter{animation:enter .5s var(--spring) both}
.enter-back{animation:enterBack .5s var(--spring) both}
@keyframes enter{from{opacity:0;transform:translateX(28px)}to{opacity:1;transform:none}}
@keyframes enterBack{from{opacity:0;transform:translateX(-28px)}to{opacity:1;transform:none}}
@keyframes fadeIn{from{opacity:0}to{opacity:1}}
@keyframes rise{from{opacity:0;transform:translateY(14px) scale(.985)}to{opacity:1;transform:none}}
.stagger>*{animation:rise .55s var(--spring) both}
.stagger>*:nth-child(1){animation-delay:.02s}.stagger>*:nth-child(2){animation-delay:.06s}.stagger>*:nth-child(3){animation-delay:.1s}.stagger>*:nth-child(4){animation-delay:.14s}
.stagger>*:nth-child(5){animation-delay:.18s}.stagger>*:nth-child(6){animation-delay:.22s}.stagger>*:nth-child(7){animation-delay:.26s}.stagger>*:nth-child(n+8){animation-delay:.3s}
::view-transition-old(root){animation:.32s var(--spring) both vtOut}
::view-transition-new(root){animation:.45s var(--spring) both vtIn}
@keyframes vtOut{to{opacity:0;transform:translateX(-18px)}}
@keyframes vtIn{from{opacity:0;transform:translateX(24px)}}

/* large title (iOS) */
.lt{padding:14px 0 10px}
.lt small{display:block;color:var(--label2);font-size:.82rem;font-weight:500;letter-spacing:.01em}
.lt h1{margin:2px 0 0;font-size:clamp(1.75rem,4.2vw,2.3rem);line-height:1.2;letter-spacing:-.02em;font-weight:700;text-wrap:balance}
.lt p{margin:8px 0 0;color:var(--label2);max-width:60ch}

/* ---------- grouped lists (iOS) ---------- */
.group{background:var(--bg2);border-radius:var(--r2);overflow:hidden;box-shadow:0 0 0 .5px var(--sep)}
.group+.gh{margin-top:24px}
.gh{font-size:.78rem;font-weight:600;color:var(--label2);margin:22px 4px 8px;text-transform:none;letter-spacing:.01em;display:flex;align-items:center;gap:8px}
.gh .r{margin-left:auto;font-weight:500}
.gf{font-size:.78rem;color:var(--label2);margin:8px 6px 0;line-height:1.6}
.cell{position:relative;display:flex;align-items:center;gap:12px;padding:11px 16px;min-height:48px;color:var(--label);cursor:pointer;transition:background .2s}
.cell+.cell::before{content:"";position:absolute;top:0;left:52px;right:0;height:.5px;background:var(--sep)}
.cell.noic+.cell::before,.cell.noic::before{left:16px}
.cell:hover{background:var(--fill2)}
.cell:active{background:var(--fill)}
.cell .ic{width:30px;height:30px;border-radius:8px;display:grid;place-items:center;color:#fff;flex:none}
.cell .ic svg{width:17px;height:17px}
.cell .tx{flex:1;min-width:0;line-height:1.45}
.cell .tx b{display:block;font-weight:500;font-size:.96rem}
.cell .tx small{display:block;color:var(--label2);font-size:.8rem;overflow:hidden;text-overflow:ellipsis}
.cell .rt{color:var(--label2);font-size:.85rem;display:flex;align-items:center;gap:6px;font-variant-numeric:tabular-nums;flex:none}
.chev{width:8px;height:14px;color:var(--label3);flex:none}

/* cards */
.grid{display:grid;gap:14px;grid-template-columns:repeat(auto-fill,minmax(240px,1fr))}
.card{position:relative;background:var(--bg2);border-radius:var(--r2);padding:16px 18px;box-shadow:0 0 0 .5px var(--sep),var(--shadow);transition:transform .45s var(--spring),box-shadow .35s;cursor:pointer;overflow:hidden;min-width:0}
@media (hover:hover){.card:hover{transform:translateY(-3px);box-shadow:0 0 0 .5px var(--sep),var(--shadow2)}}
.card:active{transform:scale(.985)}
.card h3{margin:8px 0 2px;font-size:1.02rem;letter-spacing:-.01em;line-height:1.35}
.card p{margin:0;color:var(--label2);font-size:.84rem;line-height:1.55}
.card .ic{width:38px;height:38px;border-radius:10px;display:grid;place-items:center;color:#fff}
.card .ic svg{width:21px;height:21px}
.card .meta{display:flex;gap:8px;align-items:center;margin-top:12px;font-size:.78rem;color:var(--label2)}
.hero{border-radius:var(--r3);padding:22px;color:#fff;background:linear-gradient(135deg,var(--c1,#0A84FF),var(--c2,#5E5CE6));box-shadow:var(--shadow2);position:relative;overflow:hidden;cursor:pointer;transition:transform .45s var(--spring)}
.hero:active{transform:scale(.99)}
.hero::after{content:"";position:absolute;inset:-40% -20% auto auto;width:60%;aspect-ratio:1;border-radius:50%;background:radial-gradient(circle,rgba(255,255,255,.28),transparent 70%);animation:float 9s ease-in-out infinite}
@keyframes float{50%{transform:translate(-12%,10%) scale(1.1)}}
.hero small{opacity:.85;font-weight:600;font-size:.78rem;letter-spacing:.03em}
.hero h2{margin:6px 0 4px;font-size:1.35rem;line-height:1.35;letter-spacing:-.01em}
.hero p{margin:0;opacity:.9;font-size:.88rem}
.hero .go{display:inline-flex;align-items:center;gap:6px;margin-top:14px;background:rgba(255,255,255,.22);backdrop-filter:blur(10px);padding:7px 14px;border-radius:99px;font-weight:600;font-size:.86rem}

/* progress ring */
.ring{--p:0;--c:var(--tint);width:72px;height:72px;position:relative;flex:none}
.ring svg{width:100%;height:100%;transform:rotate(-90deg)}
.ring circle{fill:none;stroke-width:8;stroke-linecap:round}
.ring .bgc{stroke:var(--fill)}
.ring .fg{stroke:var(--c);stroke-dasharray:100;stroke-dashoffset:100;transition:stroke-dashoffset 1.2s var(--spring) .15s}
.ring b{position:absolute;inset:0;display:grid;place-items:center;font-size:.92rem;font-variant-numeric:tabular-nums}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:12px}
.stat{display:flex;align-items:center;gap:14px;background:var(--bg2);border-radius:var(--r2);padding:14px 16px;box-shadow:0 0 0 .5px var(--sep)}
.stat .tx b{display:block;font-size:1.25rem;font-variant-numeric:tabular-nums;letter-spacing:-.01em}
.stat .tx small{color:var(--label2);font-size:.78rem;line-height:1.4;display:block}
.bar{height:6px;border-radius:99px;background:var(--fill);overflow:hidden}
.bar i{display:block;height:100%;border-radius:inherit;background:var(--c,var(--tint));width:0;transition:width 1s var(--spring) .1s}

/* buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:0;border-radius:12px;padding:11px 18px;font-weight:600;font-size:.94rem;background:var(--tint);color:#fff;cursor:pointer;transition:transform .3s var(--bounce),filter .2s,opacity .2s;text-decoration:none}
.btn:hover{filter:brightness(1.07)}
.btn:active{transform:scale(.95)}
.btn.gray{background:var(--fill);color:var(--tint)}
.btn.ghost{background:transparent;color:var(--tint);box-shadow:inset 0 0 0 1.5px color-mix(in srgb,var(--tint) 40%,transparent)}
.btn.red{background:var(--red)}
.btn.green{background:var(--green)}
.btn.sm{padding:7px 12px;font-size:.84rem;border-radius:10px}
.btn:disabled{opacity:.4;pointer-events:none}
.btn svg{width:18px;height:18px}
.row{display:flex;flex-wrap:wrap;gap:10px;align-items:center}
.chip{display:inline-flex;align-items:center;gap:6px;border:0;border-radius:99px;padding:6px 13px;font-size:.84rem;background:var(--fill);color:var(--label);cursor:pointer;transition:background .25s,color .25s,transform .3s var(--bounce)}
.chip:active{transform:scale(.93)}
.chip.on{background:var(--tint);color:#fff}
.pill{display:inline-flex;align-items:center;gap:4px;font-size:.72rem;font-weight:600;padding:2px 9px;border-radius:99px;background:color-mix(in srgb,var(--c,var(--tint)) 14%,transparent);color:var(--c,var(--tint));white-space:nowrap}

/* switch */
.sw{position:relative;width:51px;height:31px;flex:none}
.sw input{position:absolute;opacity:0;inset:0;margin:0;cursor:pointer;z-index:1}
.sw span{position:absolute;inset:0;border-radius:99px;background:var(--fill);transition:background .3s}
.sw span::after{content:"";position:absolute;top:2px;left:2px;width:27px;height:27px;border-radius:50%;background:#fff;box-shadow:0 3px 8px rgba(0,0,0,.15),0 1px 1px rgba(0,0,0,.16);transition:transform .4s var(--spring)}
.sw input:checked+span{background:var(--green)}
.sw input:checked+span::after{transform:translateX(20px)}

/* search field */
.field{position:relative}
.field input{width:100%;border:0;border-radius:11px;background:var(--fill);padding:10px 14px 10px 38px;font-size:1rem;outline:none;transition:box-shadow .25s,background .25s}
.field input:focus{background:var(--bg2);box-shadow:0 0 0 3px color-mix(in srgb,var(--tint) 30%,transparent),var(--shadow)}
.field svg{position:absolute;left:12px;top:50%;transform:translateY(-50%);width:17px;height:17px;color:var(--label3)}
select.sel{appearance:none;border:0;border-radius:10px;background:var(--fill) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 10 6'%3E%3Cpath d='M1 1l4 4 4-4' fill='none' stroke='%238e8e93' stroke-width='1.6'/%3E%3C/svg%3E") no-repeat right 10px center/10px;padding:7px 28px 7px 12px;font-size:.85rem;cursor:pointer}

/* tab bar (iOS) */
.tabbar{display:none}

/* ---------- reader (教本) ---------- */
.crumb{display:flex;flex-wrap:wrap;gap:6px;align-items:center;font-size:.78rem;color:var(--label2);margin:10px 0 2px}
.crumb a{color:var(--label2)}
.crumb a:hover{color:var(--tint)}
.doc{--sheet:var(--bg2);--ink:var(--label);--muted:var(--label2);--line:var(--sep);--blue:var(--tint);--navy:#1c3a5e;--on-dark:#fff;
  --font-head:var(--font-my);
  background:var(--bg2);border-radius:var(--r3);box-shadow:0 0 0 .5px var(--sep),var(--shadow);overflow:hidden;font-family:var(--font-my);line-height:2;font-size:1rem}
.doc .pad{padding:28px clamp(18px,4.5vw,48px) 34px}
.doc img{max-width:100%;height:auto}
.doc .chap{border-radius:0}
.doc[data-lang="mm"] .jab{display:none!important}
.doc[data-lang="ja"] .mmb:not(.rev){display:none!important}
.doc .jab{font-family:var(--font-jp);line-height:1.95}
.doc[data-lang="both"] p.jab,.doc[data-lang="both"] div.jab{border-left:3px solid color-mix(in srgb,var(--tint) 55%,transparent);padding-left:12px;margin-bottom:.35em}
.doc[data-lang="both"] p.mmb{padding-left:15px;font-size:.95em;color:color-mix(in srgb,var(--label) 82%,var(--label2))}
.doc[data-lang="both"] .jah{display:block;font-size:.82em;color:var(--tint);margin-bottom:2px}
.doc[data-lang="ja"] p.jab{cursor:pointer}
.doc[data-lang="ja"] .mmb.rev{display:block;margin:-.2em 0 .9em;padding:8px 12px;border-radius:10px;background:color-mix(in srgb,var(--tint) 8%,var(--bg2));font-size:.93em;animation:rise .35s var(--spring)}
.doc .jab[data-pg]::before{content:"p." attr(data-pg);float:right;margin:0 0 0 10px;font:600 10px/2.2 var(--font-jp);color:var(--label3)}
.doc .ux-has{border-radius:3px;cursor:pointer;transition:background .2s}
.doc .ux-has:hover{background:color-mix(in srgb,var(--yellow) 32%,transparent)}
.doc rt{font-size:.5em;color:var(--label2);font-family:var(--font-jp);font-weight:400}
.nofuri .doc rt{display:none}
.doc .jpx{font-family:var(--font-jp);font-size:.92em}
.doc details.kyo-rel{border-radius:12px}
.doc .ex-kyo a,.doc .ex-dup a{cursor:pointer}
.doc .tbl{overflow-x:auto}
.read-end{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:22px}
.nav-btn{display:flex;flex-direction:column;gap:2px;padding:14px 16px;border-radius:var(--r2);background:var(--bg2);box-shadow:0 0 0 .5px var(--sep);color:var(--label);cursor:pointer;transition:transform .35s var(--spring),box-shadow .3s;min-width:0}
.nav-btn:hover{box-shadow:0 0 0 .5px var(--sep),var(--shadow2);transform:translateY(-2px)}
.nav-btn small{color:var(--label2);font-size:.75rem}
.nav-btn b{font-weight:600;font-size:.9rem;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.nav-btn.next{text-align:right}
.done-pill{display:flex;align-items:center;justify-content:center;gap:8px;margin:18px auto 0;color:var(--green);font-weight:600;font-size:.88rem;opacity:0;transform:scale(.9);transition:opacity .4s,transform .5s var(--bounce)}
.done-pill.show{opacity:1;transform:none}
.progress-top{position:sticky;top:0;height:3px;z-index:3;background:transparent}
.progress-top i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--tint),var(--purple));border-radius:0 99px 99px 0;transition:width .15s linear}

/* ---------- question player ---------- */
.qwrap{max-width:860px;margin:0 auto}
.qhead{display:flex;align-items:center;gap:10px;margin:12px 0 10px}
.qhead .num{font-weight:700;font-size:.82rem;padding:4px 10px;border-radius:8px;background:var(--tint);color:#fff;font-variant-numeric:tabular-nums}
.qhead .ttl{flex:1;min-width:0;font-weight:600;line-height:1.4}
.qhead .ttl small{display:block;font-weight:400;color:var(--label2);font-size:.8rem}
.qbody{padding:22px clamp(16px,4vw,32px)}
.opts{list-style:none;margin:16px 0 0;padding:0;display:flex;flex-direction:column;gap:10px}
.opt{display:flex;gap:12px;align-items:flex-start;padding:12px 14px;border-radius:14px;background:var(--bg3);border:2px solid transparent;cursor:pointer;transition:transform .35s var(--spring),border-color .25s,background .25s}
.opt:hover{border-color:color-mix(in srgb,var(--tint) 30%,transparent)}
.opt:active{transform:scale(.985)}
.opt .n{width:30px;height:30px;border-radius:50%;flex:none;display:grid;place-items:center;font-weight:700;font-size:.88rem;background:var(--bg2);box-shadow:0 0 0 1.5px var(--sep);transition:all .35s var(--spring)}
.opt .ot{flex:1;min-width:0}
.opt .ot p{margin:0 0 4px}
.opt.pick{border-color:var(--tint)}
.opt.pick .n{background:var(--tint);color:#fff;box-shadow:none}
.opt.ok{border-color:var(--green);background:color-mix(in srgb,var(--green) 10%,var(--bg3))}
.opt.ok .n{background:var(--green);color:#fff;box-shadow:none;animation:pop .5s var(--bounce)}
.opt.ng{border-color:var(--red);background:color-mix(in srgb,var(--red) 9%,var(--bg3));animation:shake .45s}
.opt.ng .n{background:var(--red);color:#fff;box-shadow:none}
.opt.dim{opacity:.55}
.done .opt{cursor:default}
@keyframes pop{0%{transform:scale(.6)}60%{transform:scale(1.18)}100%{transform:scale(1)}}
@keyframes shake{20%{transform:translateX(-7px)}40%{transform:translateX(6px)}60%{transform:translateX(-4px)}80%{transform:translateX(2px)}}
.verdict{display:flex;align-items:center;gap:12px;margin:16px 0 0;padding:14px 16px;border-radius:14px;font-weight:600;animation:rise .45s var(--spring)}
.verdict.ok{background:color-mix(in srgb,var(--green) 14%,var(--bg2));color:var(--green)}
.verdict.ng{background:color-mix(in srgb,var(--red) 12%,var(--bg2));color:var(--red)}
.verdict svg{width:28px;height:28px;flex:none}
.verdict small{display:block;color:var(--label2);font-weight:500}
.exp{margin-top:14px;overflow:hidden;animation:rise .5s var(--spring) .08s both}
.exp .pad{padding:20px clamp(16px,4vw,32px)}
.qnav{position:sticky;bottom:0;display:flex;gap:10px;justify-content:space-between;align-items:center;padding:12px 0 calc(12px + env(safe-area-inset-bottom,0px));margin-top:18px;background:linear-gradient(to top,var(--bg) 70%,transparent)}
.qnav .mid{font-size:.82rem;color:var(--label2);font-variant-numeric:tabular-nums}
.qgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(42px,1fr));gap:8px}
.qgrid a{aspect-ratio:1;display:grid;place-items:center;border-radius:12px;background:var(--bg2);box-shadow:0 0 0 .5px var(--sep);color:var(--label);font-weight:600;font-size:.86rem;font-variant-numeric:tabular-nums;transition:transform .35s var(--bounce),background .3s}
.qgrid a:hover{transform:scale(1.08)}
.qgrid a.ok{background:var(--green);color:#fff;box-shadow:none}
.qgrid a.ng{background:var(--red);color:#fff;box-shadow:none}
.qgrid a.cur{box-shadow:0 0 0 2.5px var(--tint)}
.timer{display:inline-flex;align-items:center;gap:6px;font-variant-numeric:tabular-nums;font-weight:600;font-size:.86rem;padding:5px 12px;border-radius:99px;background:var(--fill)}

/* ---------- dictionary ---------- */
.scroll-x{display:flex;gap:8px;overflow-x:auto;padding:2px 2px 6px;scrollbar-width:none}
.scroll-x::-webkit-scrollbar{display:none}
.de-list{display:flex;flex-direction:column}
.de{display:block;padding:12px 16px;cursor:pointer;position:relative;transition:background .2s}
.de+.de::before{content:"";position:absolute;top:0;left:16px;right:0;height:.5px;background:var(--sep)}
.de:hover{background:var(--fill2)}
.de .j{font-family:var(--font-jp);font-weight:600;font-size:1.06rem}
.de .r{font-family:var(--font-jp);color:var(--teal);font-size:.86rem;margin-left:8px}
.de .m{display:block;font-family:var(--font-my);font-size:.92rem;line-height:1.75;margin-top:2px}
.de .e{display:block;color:var(--label2);font-size:.8rem}
.de .tags{display:flex;flex-wrap:wrap;gap:5px;margin-top:6px}
.term{font-family:var(--font-jp);font-size:clamp(2rem,6vw,3rem);font-weight:700;line-height:1.25;letter-spacing:.01em}
.reading{font-family:var(--font-jp);color:var(--teal);font-size:1.15rem;font-weight:500}
.kana-row{display:flex;flex-wrap:wrap;gap:6px}
.kana-row button{min-width:44px;border:0;border-radius:10px;background:var(--bg2);box-shadow:0 0 0 .5px var(--sep);padding:6px 10px;font-family:var(--font-jp);font-weight:600;cursor:pointer;transition:transform .3s var(--bounce),background .25s,color .25s}
.kana-row button small{display:block;font-size:.65rem;color:var(--label2);font-weight:500}
.kana-row button.on{background:var(--tint);color:#fff}
.kana-row button.on small{color:rgba(255,255,255,.8)}
.kana-row button:active{transform:scale(.92)}

/* flashcards */
.fc-stage{perspective:1400px;max-width:560px;margin:10px auto 0}
.fc{position:relative;height:min(52vh,380px);transform-style:preserve-3d;transition:transform .7s var(--spring);cursor:pointer;touch-action:pan-y}
.fc.flip{transform:rotateY(180deg)}
.fc .face{position:absolute;inset:0;backface-visibility:hidden;-webkit-backface-visibility:hidden;border-radius:24px;background:var(--bg2);box-shadow:0 0 0 .5px var(--sep),var(--shadow2);display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:24px;gap:10px}
.fc .back{transform:rotateY(180deg)}
.fc .face .term{font-size:clamp(1.8rem,7vw,2.8rem)}
.fc .face .m{font-family:var(--font-my);font-size:1.1rem;line-height:1.8}
.fc .hint{position:absolute;bottom:14px;font-size:.75rem;color:var(--label3)}
.fc.out-l{transition:transform .45s var(--spring),opacity .45s;transform:translateX(-120%) rotate(-12deg);opacity:0}
.fc.out-r{transition:transform .45s var(--spring),opacity .45s;transform:translateX(120%) rotate(12deg);opacity:0}
.fc-btns{display:grid;grid-template-columns:1fr 1fr;gap:12px;max-width:560px;margin:18px auto 0}

/* ---------- overlays ---------- */
#layer{position:fixed;inset:0;pointer-events:none;z-index:50}
.scrim{position:fixed;inset:0;background:rgba(0,0,0,.28);opacity:0;transition:opacity .35s;pointer-events:auto}
.scrim.show{opacity:1}
.sheet{position:fixed;left:50%;bottom:0;width:min(640px,100%);max-height:88vh;transform:translate(-50%,105%);background:var(--bg2);border-radius:var(--r3) var(--r3) 0 0;box-shadow:var(--shadow2);
  transition:transform .55s var(--spring);pointer-events:auto;display:flex;flex-direction:column;padding-bottom:env(safe-area-inset-bottom,0px)}
.sheet.show{transform:translate(-50%,0)}
@media (min-width:768px){.sheet{bottom:auto;top:50%;border-radius:var(--r3);transform:translate(-50%,-45%) scale(.94);opacity:0;transition:transform .5s var(--spring),opacity .3s}.sheet.show{transform:translate(-50%,-50%);opacity:1}}
.sheet .grab{width:38px;height:5px;border-radius:99px;background:var(--label3);margin:8px auto 0;opacity:.5}
.sheet .sh-h{display:flex;align-items:center;gap:10px;padding:12px 18px 8px}
.sheet .sh-h b{flex:1;font-size:1.05rem}
.sheet .sh-b{overflow:auto;padding:4px 18px 20px}
.pop{position:fixed;z-index:60;width:min(340px,calc(100vw - 24px));background:var(--elev);border-radius:16px;box-shadow:0 0 0 .5px var(--sep),var(--shadow2);padding:14px 16px;pointer-events:auto;transform-origin:top center;animation:popIn .35s var(--spring)}
@keyframes popIn{from{opacity:0;transform:scale(.92) translateY(-6px)}}
.pop .pj{font-family:var(--font-jp);font-weight:700;font-size:1.15rem}
.pop .pr{font-family:var(--font-jp);color:var(--teal);font-size:.88rem;margin-left:6px}
.pop .pl{margin-top:6px;font-size:.9rem;line-height:1.7}
.pop .pl small{display:block;color:var(--label2);font-size:.78rem}
.pop .pk{display:flex;gap:8px;font-size:.84rem;margin-top:4px}
.pop .pk b{font-family:var(--font-jp);font-size:1.05rem}
.pop .acts{display:flex;gap:8px;margin-top:10px}
.toast{position:fixed;left:50%;bottom:calc(96px + env(safe-area-inset-bottom,0px));transform:translate(-50%,20px) scale(.96);opacity:0;background:var(--elev);color:var(--label);padding:10px 18px;border-radius:99px;box-shadow:0 0 0 .5px var(--sep),var(--shadow2);font-size:.88rem;font-weight:500;pointer-events:none;transition:transform .45s var(--spring),opacity .3s;z-index:70;display:flex;align-items:center;gap:8px;white-space:nowrap}
.toast.show{transform:translate(-50%,0);opacity:1}
.toast svg{width:18px;height:18px;color:var(--green)}
.skel{border-radius:12px;background:linear-gradient(90deg,var(--fill2) 25%,var(--fill) 37%,var(--fill2) 63%);background-size:400% 100%;animation:shimmer 1.3s ease infinite}
@keyframes shimmer{0%{background-position:100% 50%}100%{background-position:0 50%}}
.empty{text-align:center;color:var(--label2);padding:40px 16px}
.empty svg{width:46px;height:46px;color:var(--label3);margin-bottom:8px}
.muted{color:var(--label2)}
.small{font-size:.82rem}
.confetti{position:fixed;inset:0;pointer-events:none;z-index:80;overflow:hidden}
.confetti i{position:absolute;top:-12px;width:8px;height:14px;border-radius:2px;animation:fall 1.6s cubic-bezier(.2,.6,.4,1) forwards}
@keyframes fall{to{transform:translate(var(--dx),110vh) rotate(var(--rot));opacity:.9}}

/* splash */
.splash{position:fixed;inset:0;z-index:100;display:grid;place-items:center;background:var(--bg);transition:opacity .5s,visibility .5s}
.splash.hide{opacity:0;visibility:hidden}
.splash-in{display:flex;flex-direction:column;align-items:center;gap:6px;animation:rise .7s var(--spring)}
.splash b{font-size:1.4rem;letter-spacing:-.01em;margin-top:8px}
.splash span{color:var(--label2);font-size:.85rem}
.logo-tile{width:76px;height:76px;border-radius:20px;display:grid;place-items:center;color:#fff;background:linear-gradient(140deg,#0A84FF,#5E5CE6 60%,#BF5AF2);box-shadow:0 10px 30px rgba(10,132,255,.35)}
.logo-tile svg{width:60%;height:60%}
.spin{width:22px;height:22px;border-radius:50%;border:2.5px solid var(--fill);border-top-color:var(--tint);animation:rot .8s linear infinite;margin-top:14px}
@keyframes rot{to{transform:rotate(360deg)}}

/* ---------- phone / tablet ---------- */
@media (max-width:1023px){
  :root{--side:0px}
  .app{grid-template-columns:1fr}
  .sidebar{position:fixed;inset:0 auto 0 0;width:300px;transform:translateX(-105%);transition:transform .5s var(--spring);box-shadow:var(--shadow2);z-index:40}
  .app.side-open .sidebar{transform:none}
}
@media (max-width:767px){
  body{--fs:16px}
  .sidebar{display:none}
  .tabbar{display:grid;grid-template-columns:repeat(5,1fr);position:fixed;left:0;right:0;bottom:0;z-index:20;padding:6px max(8px,env(safe-area-inset-right,0px)) calc(4px + env(safe-area-inset-bottom,0px)) max(8px,env(safe-area-inset-left,0px));
    background:var(--mat);backdrop-filter:saturate(180%) blur(24px);-webkit-backdrop-filter:saturate(180%) blur(24px);border-top:.5px solid var(--sep)}
  .tab{display:flex;flex-direction:column;align-items:center;gap:2px;border:0;background:none;color:var(--label3);font-size:.62rem;font-weight:500;padding:4px 0;cursor:pointer;transition:color .25s}
  .tab svg{width:25px;height:25px;transition:transform .45s var(--bounce)}
  .tab.on{color:var(--tint)}
  .tab.on svg{transform:translateY(-1px) scale(1.06)}
  .tab:active svg{transform:scale(.85)}
  .page{padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px))}
  .doc{border-radius:16px}
  .doc .pad{padding:20px 16px 24px}
  .grid{grid-template-columns:1fr 1fr;gap:10px}
  .card{padding:14px}
  .read-end{grid-template-columns:1fr 1fr}
  .tb-hide-sm{display:none!important}
  .seg button{padding:4px 9px}
}
@media (max-width:420px){.grid{grid-template-columns:1fr}}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}}
/* fixes */
a.card,a.cell{color:var(--label)}
.hero .go{white-space:nowrap}
.hero .go svg{width:18px;height:18px}
.chip small{margin-left:2px}
.stat .ring+.tx,.stat .tx{min-width:0}
.de .j,.de .r{display:inline}
.scroll-x>*{flex:none;white-space:nowrap}
:where(h1,h2,h3,summary,.chip,.btn,.pill,.gh,.lt p) svg{width:18px;height:18px;vertical-align:-3px}
details>summary{list-style:none}details>summary::-webkit-details-marker{display:none}
a.de{color:var(--label)}