:root{
  --bg:#0d1017; --bg-2:#141922; --card:#171d28; --card-2:#1d2430;
  --line:#262f3d; --line-2:#33405280;
  --ink:#e8edf5; --ink-2:#9aa8bd; --ink-3:#6b7a91;
  --accent:#5b9cff; --accent-2:#8b7bff;
  --new:#5b9cff; --weak:#ff6b6b; --learning:#ffab4d; --strong:#4ecb8f; --mastered:#31c48d;
  --again:#e5484d; --hard:#d98324; --good:#3aa76d; --easy:#4a8fe0;
  --r:14px; --shadow:0 6px 28px rgba(0,0,0,.35);
  --max:920px;
}
@media (prefers-color-scheme: light){
  :root{
    --bg:#f6f7fa; --bg-2:#fff; --card:#fff; --card-2:#f2f4f8;
    --line:#e2e6ee; --line-2:#e8ecf4;
    --ink:#141922; --ink-2:#55607a; --ink-3:#8390a8;
    --shadow:0 4px 20px rgba(20,30,60,.08);
  }
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
html{
  /* Paint the notch/home-indicator strips in the app colour rather than white */
  background:var(--bg);
  -webkit-text-size-adjust:100%;
}
body{
  background:var(--bg); color:var(--ink);
  font:15px/1.55 -apple-system,BlinkMacSystemFont,"Segoe UI",Inter,Roboto,Helvetica,Arial,sans-serif;
  -webkit-font-smoothing:antialiased;
  overscroll-behavior-y:none;
  /* Stop iOS from showing the magnifier / copy bubble on taps */
  -webkit-touch-callout:none;
  -webkit-tap-highlight-color:transparent;
  min-height:100vh;
  min-height:100dvh;
}
/* Text the user may genuinely want to select */
.word,.def,.ex,.witem .d{-webkit-touch-callout:default;-webkit-user-select:text;user-select:text}
/* Inputs must stay 16px+ or iOS zooms the page when they get focus */
input,select,textarea{font-size:16px}
button{font:inherit;color:inherit;background:none;border:none;cursor:pointer}
h1,h2,h3{margin:0;font-weight:650;letter-spacing:-.01em}

/* ---------- top bar ---------- */
.topbar{
  position:sticky; top:0; z-index:40; display:flex; align-items:center; gap:12px;
  padding:calc(10px + env(safe-area-inset-top)) max(14px,env(safe-area-inset-right))
          10px max(14px,env(safe-area-inset-left));
  background:color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter:blur(14px); border-bottom:1px solid var(--line);
}
.brand{display:flex;align-items:center;gap:9px;font-weight:700;letter-spacing:-.02em;font-size:16px}
.logo{
  width:22px;height:22px;border-radius:7px;
  background:linear-gradient(140deg,var(--accent),var(--accent-2));
  box-shadow:0 2px 10px rgba(91,156,255,.4);
}
.tabs{display:flex;gap:2px;margin-left:auto}
.tab{
  padding:7px 13px;border-radius:9px;color:var(--ink-2);font-size:14px;font-weight:550;
  transition:background .15s,color .15s;
}
.tab:hover{background:var(--card-2);color:var(--ink)}
.tab.on{background:var(--card);color:var(--ink);box-shadow:inset 0 0 0 1px var(--line)}
.icon-btn{
  width:34px;height:34px;display:grid;place-items:center;border-radius:9px;color:var(--ink-2);
}
.icon-btn:hover{background:var(--card-2);color:var(--ink)}
@media (max-width:620px){
  .tabs{margin-left:auto;gap:0}
  .tab{padding:7px 9px;font-size:13px}
  .brand span:last-child{display:none}
}

/* ---------- layout ---------- */
main{
  max-width:var(--max); margin:0 auto;
  padding:22px max(14px,env(safe-area-inset-right))
          calc(60px + env(safe-area-inset-bottom)) max(14px,env(safe-area-inset-left));
}
.row{display:flex;align-items:center;gap:10px}
.muted{color:var(--ink-2)}
.small{font-size:13px}
.tiny{font-size:12px}

/* ---------- cards & grids ---------- */
.panel{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:18px}
.grid{display:grid;gap:12px}
.grid.s2{grid-template-columns:repeat(2,1fr)}
.grid.s3{grid-template-columns:repeat(3,1fr)}
@media (max-width:620px){.grid.s3{grid-template-columns:repeat(2,1fr)}}

/* ---------- home ---------- */
.hero{display:flex;gap:26px;align-items:center;flex-wrap:wrap;margin-bottom:20px}
.ring{position:relative;width:132px;height:132px;flex:none}
.ring svg{transform:rotate(-90deg)}
.ring .val{
  position:absolute;inset:0;display:grid;place-content:center;text-align:center;line-height:1.1;
}
.ring .val b{font-size:31px;font-weight:700;letter-spacing:-.03em}
.ring .val span{font-size:11px;color:var(--ink-2);text-transform:uppercase;letter-spacing:.09em}
.hero-main{flex:1;min-width:230px}
.hero-main h1{font-size:23px;margin-bottom:4px}

.bar{display:flex;height:9px;border-radius:99px;overflow:hidden;background:var(--card-2);margin:14px 0 10px}
.bar i{display:block;height:100%}
.legend{display:flex;flex-wrap:wrap;gap:6px 14px}
.legend b{display:inline-flex;align-items:center;gap:6px;font-weight:500;font-size:12.5px;color:var(--ink-2)}
.legend b::before{content:"";width:8px;height:8px;border-radius:3px;background:var(--c)}
.legend b em{font-style:normal;color:var(--ink);font-weight:650}

.actions{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:18px 0}
@media (max-width:560px){.actions{grid-template-columns:1fr}}
.action{
  display:flex;flex-direction:column;gap:5px;text-align:left;padding:17px 18px;border-radius:var(--r);
  background:var(--card);border:1px solid var(--line);transition:transform .12s,border-color .15s;
}
.action:hover{transform:translateY(-1px);border-color:var(--accent)}
.action.primary{background:linear-gradient(135deg,var(--accent),var(--accent-2));border-color:transparent;color:#fff}
.action.primary .sub{color:#ffffffcc}
.action .t{font-size:16.5px;font-weight:650;display:flex;align-items:center;gap:9px}
.action .sub{font-size:13px;color:var(--ink-2)}
.pill{
  font-size:11.5px;font-weight:700;padding:2px 8px;border-radius:99px;
  background:#ffffff2b;letter-spacing:.02em;
}
.action:not(.primary) .pill{background:var(--card-2);color:var(--ink-2)}

.stat{background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:14px 16px}
.stat b{display:block;font-size:22px;font-weight:700;letter-spacing:-.02em}
.stat span{font-size:12.5px;color:var(--ink-2)}

/* ---------- study card ---------- */
.stage{max-width:660px;margin:0 auto}
.progress{height:4px;background:var(--card-2);border-radius:99px;overflow:hidden;margin-bottom:20px}
.progress i{display:block;height:100%;background:linear-gradient(90deg,var(--accent),var(--accent-2));transition:width .3s}

.qcard{
  background:var(--card);border:1px solid var(--line);border-radius:20px;box-shadow:var(--shadow);
  padding:34px 28px;min-height:270px;display:flex;flex-direction:column;
}
.qhead{display:flex;align-items:center;gap:9px;margin-bottom:auto}
.badge{font-size:11px;font-weight:700;letter-spacing:.07em;text-transform:uppercase;
  padding:3px 9px;border-radius:99px;background:var(--card-2);color:var(--ink-2)}
.badge[data-b=new]{background:color-mix(in srgb,var(--new) 18%,transparent);color:var(--new)}
.badge[data-b=weak]{background:color-mix(in srgb,var(--weak) 18%,transparent);color:var(--weak)}
.badge[data-b=learning]{background:color-mix(in srgb,var(--learning) 18%,transparent);color:var(--learning)}
.badge[data-b=strong],.badge[data-b=mastered]{background:color-mix(in srgb,var(--strong) 18%,transparent);color:var(--strong)}

.word{font-size:40px;font-weight:700;letter-spacing:-.03em;text-align:center;margin:16px 0 4px;word-break:break-word}
@media (max-width:480px){.word{font-size:33px}}
.pos{text-align:center;color:var(--ink-3);font-size:13.5px;font-style:italic;margin-bottom:14px}
.reveal-hint{text-align:center;color:var(--ink-3);font-size:13px;margin-top:auto;padding-top:18px}

.answer{border-top:1px dashed var(--line-2);margin-top:18px;padding-top:18px;animation:fade .22s ease}
@keyframes fade{from{opacity:0;transform:translateY(5px)}to{opacity:1;transform:none}}
.def{font-size:20px;font-weight:600;text-align:center;letter-spacing:-.01em}
.ex{
  margin-top:14px;padding:13px 15px;background:var(--card-2);border-radius:11px;
  border-left:3px solid var(--accent);font-size:14.5px;color:var(--ink-2);font-style:italic;
}
.ex em{font-style:normal;font-weight:700;color:var(--ink);background:color-mix(in srgb,var(--accent) 18%,transparent);
  padding:0 3px;border-radius:3px}

.speak-btn{
  display:inline-flex;align-items:center;justify-content:center;gap:7px;margin:0 auto;
  padding:8px 15px;border-radius:99px;background:var(--card-2);border:1px solid var(--line);
  font-size:13.5px;color:var(--ink-2);font-weight:550;
}
.speak-btn:hover{color:var(--ink);border-color:var(--accent)}
.speak-btn.on{color:var(--accent);border-color:var(--accent)}

.grades{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-top:16px}
.grade{
  padding:12px 4px;border-radius:12px;border:1px solid var(--line);background:var(--card);
  display:flex;flex-direction:column;align-items:center;gap:2px;transition:transform .1s,background .15s;
}
.grade:hover{transform:translateY(-1px)}
.grade b{font-size:14px;font-weight:650}
.grade span{font-size:11.5px;color:var(--ink-3);font-variant-numeric:tabular-nums}
.grade[data-g="1"]{border-color:color-mix(in srgb,var(--again) 45%,var(--line))}
.grade[data-g="1"]:hover{background:color-mix(in srgb,var(--again) 15%,var(--card))}
.grade[data-g="1"] b{color:var(--again)}
.grade[data-g="2"] b{color:var(--hard)}
.grade[data-g="3"] b{color:var(--good)}
.grade[data-g="4"] b{color:var(--easy)}
.grade[data-g="2"]:hover{background:color-mix(in srgb,var(--hard) 14%,var(--card))}
.grade[data-g="3"]:hover{background:color-mix(in srgb,var(--good) 14%,var(--card))}
.grade[data-g="4"]:hover{background:color-mix(in srgb,var(--easy) 14%,var(--card))}

.btn{
  padding:12px 20px;border-radius:12px;background:var(--card);border:1px solid var(--line);
  font-weight:600;font-size:14.5px;transition:border-color .15s,background .15s;
}
.btn:hover{border-color:var(--accent)}
.btn.wide{width:100%}
.btn.fill{background:linear-gradient(135deg,var(--accent),var(--accent-2));color:#fff;border-color:transparent}
.btn.ghost{background:transparent}
.btn.danger{color:var(--again);border-color:color-mix(in srgb,var(--again) 40%,var(--line))}

/* ---------- listen ---------- */
.player{text-align:center;padding:30px 24px}
.player .word{font-size:44px;margin-bottom:6px}
.player .def{font-size:19px;margin-top:12px;color:var(--ink)}
.player .ex{text-align:left}
.now-field{color:var(--accent);font-size:11.5px;letter-spacing:.1em;text-transform:uppercase;font-weight:700;height:16px}
.controls{display:flex;align-items:center;justify-content:center;gap:10px;margin-top:24px}
.circle{
  width:48px;height:48px;border-radius:50%;display:grid;place-items:center;
  background:var(--card-2);border:1px solid var(--line);color:var(--ink-2);
}
.circle:hover{color:var(--ink);border-color:var(--accent)}
.circle.big{
  width:64px;height:64px;background:linear-gradient(135deg,var(--accent),var(--accent-2));
  color:#fff;border-color:transparent;box-shadow:0 6px 20px rgba(91,156,255,.35);
}
.seg{display:inline-flex;background:var(--card-2);border:1px solid var(--line);border-radius:10px;padding:3px;gap:2px;flex-wrap:wrap}
.seg button{padding:6px 11px;border-radius:7px;font-size:13px;color:var(--ink-2);font-weight:550}
.seg button.on{background:var(--card);color:var(--ink);box-shadow:0 1px 4px rgba(0,0,0,.18)}

/* ---------- browse ---------- */
.toolbar{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin-bottom:14px}
.search{
  flex:1;min-width:170px;padding:10px 14px;border-radius:11px;background:var(--card);
  border:1px solid var(--line);color:var(--ink);font-size:14.5px;
}
.search:focus{outline:none;border-color:var(--accent)}
.wlist{display:flex;flex-direction:column;gap:7px}
.witem{
  display:flex;align-items:center;gap:13px;padding:12px 15px;background:var(--card);
  border:1px solid var(--line);border-radius:12px;text-align:left;width:100%;
}
.witem:hover{border-color:var(--accent)}
.witem .w{font-weight:650;font-size:15px;min-width:112px}
.witem .d{color:var(--ink-2);font-size:13.5px;flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.mbar{width:54px;height:5px;border-radius:99px;background:var(--card-2);overflow:hidden;flex:none}
.mbar i{display:block;height:100%}
.witem .spk{color:var(--ink-3);flex:none;padding:4px}
.witem .spk:hover{color:var(--accent)}
@media (max-width:560px){.witem .d{display:none}}

.detail{margin-top:8px;padding:15px;background:var(--card-2);border-radius:12px}

/* ---------- settings ---------- */
.field{display:flex;align-items:center;justify-content:space-between;gap:14px;padding:13px 0;border-bottom:1px solid var(--line)}
.field:last-child{border-bottom:none}
.field label{font-weight:550;font-size:14.5px}
.field .hint{font-size:12.5px;color:var(--ink-3);margin-top:2px}
select,input[type=number]{
  padding:8px 11px;border-radius:9px;background:var(--card-2);border:1px solid var(--line);
  color:var(--ink);font-size:14px;max-width:230px;
}
select:focus,input:focus{outline:none;border-color:var(--accent)}
input[type=range]{accent-color:var(--accent);width:150px}
.switch{width:44px;height:26px;border-radius:99px;background:var(--card-2);border:1px solid var(--line);position:relative;flex:none;transition:background .18s}
.switch::after{content:"";position:absolute;top:2px;left:2px;width:20px;height:20px;border-radius:50%;background:var(--ink-3);transition:transform .18s,background .18s}
.switch.on{background:color-mix(in srgb,var(--accent) 35%,transparent);border-color:var(--accent)}
.switch.on::after{transform:translateX(18px);background:var(--accent)}

/* ---------- misc ---------- */
.empty{text-align:center;padding:52px 20px;color:var(--ink-2)}
.empty .big{font-size:42px;margin-bottom:10px}
.toast{
  position:fixed;left:50%;bottom:calc(26px + env(safe-area-inset-bottom));
  transform:translateX(-50%);z-index:90;
  background:var(--card);border:1px solid var(--line);box-shadow:var(--shadow);
  padding:11px 18px;border-radius:11px;font-size:14px;animation:fade .2s;
}
.sec-title{font-size:12px;text-transform:uppercase;letter-spacing:.09em;color:var(--ink-3);font-weight:700;margin:26px 0 10px}

/* ---------- iOS / touch ---------- */
@media (hover:none){
  /* Hover styles stick after a tap on touch devices, so drop them */
  .tab:hover,.icon-btn:hover,.witem:hover,.action:hover,.btn:hover,
  .grade:hover,.circle:hover,.speak-btn:hover{
    background:inherit;transform:none;border-color:var(--line);
  }
  .action:hover{border-color:var(--line)}
  .action.primary:hover{border-color:transparent}
  .btn.fill:hover{border-color:transparent}
  /* Comfortable thumb targets */
  .grade{padding:15px 4px}
  .tab{padding:9px 11px}
  .circle{width:54px;height:54px}
  .circle.big{width:70px;height:70px}
  .witem{padding:14px 15px}
  .brand{padding:8px 0}
  /* A 16px-tall slider is unusable with a thumb */
  input[type=range]{height:36px}
  input[type=range]::-webkit-slider-thumb{width:26px;height:26px}
  select,input[type=number],input[type=text]{min-height:42px}
  .switch{width:52px;height:32px}
  .switch::after{width:26px;height:26px}
  .switch.on::after{transform:translateX(20px)}
  .speak-btn{padding:11px 18px}
  .icon-btn{width:42px;height:42px}
}
/* Standalone (added to the Home Screen): no browser chrome to scroll away */
@media all and (display-mode:standalone){
  body{overscroll-behavior:none}
}