:root{
  --bg:#f5f7fa; --surface:#fff; --surface-2:#eef2f6; --line:#dde3ea;
  --ink:#0f1722; --ink-2:#4a5666; --ink-3:#7b8695;
  --accent:#0f766e; --accent-ink:#fff; --accent-soft:#d8f0ec;
  --left:#1d5fd1; --left-soft:#e0eafb; --right:#cf2e2e; --right-soft:#fbe4e2;
  --warn-bg:#fff7e6; --warn-line:#f2d59a; --warn-ink:#6b4a00;
  --band-0:#ffffff; --band-1:#f3f6f9; --band-2:#e9eef3; --band-3:#dfe6ed;
  --shadow:0 1px 2px rgba(15,23,34,.05),0 4px 16px rgba(15,23,34,.06);
  --r:14px;
  --font:"Inter",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --mono:"JetBrains Mono",ui-monospace,Consolas,monospace;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --bg:#0b1118; --surface:#121a24; --surface-2:#1a2431; --line:#263241;
    --ink:#e8edf3; --ink-2:#a9b4c2; --ink-3:#7d8999;
    --accent:#2dd4bf; --accent-ink:#04201d; --accent-soft:#103a36;
    --left:#6ea0ff; --left-soft:#15284a; --right:#ff7a72; --right-soft:#3d1a1a;
    --warn-bg:#2a2210; --warn-line:#5a4618; --warn-ink:#f3d693;
    --band-0:#121a24; --band-1:#161f2b; --band-2:#1b2532; --band-3:#212c3a;
    --shadow:0 1px 2px rgba(0,0,0,.3),0 6px 20px rgba(0,0,0,.25);
    color-scheme:dark;
  }
}
:root[data-theme="dark"]{
  --bg:#0b1118; --surface:#121a24; --surface-2:#1a2431; --line:#263241;
  --ink:#e8edf3; --ink-2:#a9b4c2; --ink-3:#7d8999;
  --accent:#2dd4bf; --accent-ink:#04201d; --accent-soft:#103a36;
  --left:#6ea0ff; --left-soft:#15284a; --right:#ff7a72; --right-soft:#3d1a1a;
  --warn-bg:#2a2210; --warn-line:#5a4618; --warn-ink:#f3d693;
  --band-0:#121a24; --band-1:#161f2b; --band-2:#1b2532; --band-3:#212c3a;
  color-scheme:dark;
}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.55 var(--font);-webkit-font-smoothing:antialiased}
h1,h2,h3{line-height:1.2;margin:0 0 .5em;letter-spacing:-.015em}
h1{font-size:clamp(1.9rem,4.6vw,2.9rem);font-weight:700;max-width:20ch}
h2{font-size:clamp(1.5rem,3vw,1.9rem);font-weight:700}
h3{font-size:1.05rem;font-weight:600}
p{margin:0 0 .8em}
small{font-size:.8em}
kbd{font:500 .78em var(--mono);background:var(--surface-2);border:1px solid var(--line);border-bottom-width:2px;border-radius:5px;padding:1px 6px;margin:0 1px}
[hidden]{display:none!important}

.wrap{max-width:1040px;margin:0 auto;padding:0 16px}
main.wrap{padding-top:28px;padding-bottom:40px;min-height:calc(100vh - 160px)}

/* header */
.top{background:var(--surface);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:5}
.top-in{display:flex;align-items:center;justify-content:space-between;gap:16px;height:60px}
.brand{display:flex;align-items:center;gap:10px;color:var(--ink);text-decoration:none;font-weight:700;letter-spacing:-.01em}
.brand svg{width:28px;height:28px;color:var(--accent)}
.steps{display:flex;gap:4px;list-style:none;margin:0;padding:0;counter-reset:s}
.steps li{counter-increment:s;font-size:.82rem;color:var(--ink-3);display:flex;align-items:center;gap:6px;padding:4px 8px;border-radius:99px}
.steps li::before{content:counter(s);display:grid;place-items:center;width:20px;height:20px;border-radius:50%;border:1.5px solid var(--line);font-size:.72rem;font-weight:600}
.steps li.on{color:var(--ink);font-weight:600}
.steps li.on::before{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}
.steps li.done::before{content:"✓";background:var(--accent-soft);border-color:var(--accent-soft);color:var(--accent)}
@media (max-width:640px){.steps li{font-size:0;padding:4px 2px;gap:0}.steps li.on{font-size:.78rem;gap:6px;padding:4px 6px}}

/* basics */
.eyebrow{font-size:.78rem;font-weight:600;text-transform:uppercase;letter-spacing:.08em;color:var(--accent);margin-bottom:.6em}
.lead{font-size:1.12rem;color:var(--ink-2);max-width:62ch}
.lead.sm{font-size:1rem}
.hint{color:var(--ink-3);font-size:.86rem;margin:0}
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:22px;box-shadow:var(--shadow);margin-bottom:16px}
.row{display:flex;align-items:center;gap:12px;flex-wrap:wrap}
.actions{display:flex;justify-content:space-between;gap:12px;margin-top:24px;flex-wrap:wrap}
.actions.center{justify-content:center}
.hero{padding:12px 0 24px}
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
@media (max-width:800px){.grid-3{grid-template-columns:1fr}}
.tip .ic{font-size:1.5rem;display:block;margin-bottom:8px}
.tip p{color:var(--ink-2);font-size:.93rem;margin:0}
.notice{background:var(--warn-bg);border:1px solid var(--warn-line);color:var(--warn-ink);border-radius:var(--r);padding:14px 18px;font-size:.93rem;margin:4px 0 16px}
.last{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap}
.last p{margin:0;color:var(--ink-2)}

/* buttons */
.btn{appearance:none;font:inherit;font-weight:600;font-size:.95rem;display:inline-flex;align-items:center;justify-content:center;gap:8px;border-radius:10px;padding:10px 16px;border:1px solid var(--line);background:var(--surface);color:var(--ink);cursor:pointer;transition:background .15s,border-color .15s,transform .05s;min-height:44px}
.btn:hover{background:var(--surface-2)}
.btn:active{transform:translateY(1px)}
.btn:focus-visible,.respond:focus-visible{outline:3px solid color-mix(in srgb,var(--accent) 50%,transparent);outline-offset:2px}
.btn:disabled{opacity:.45;cursor:not-allowed}
.btn.primary{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}
.btn.primary:hover{filter:brightness(1.07)}
.btn.ghost{background:transparent;border-color:transparent;color:var(--ink-2)}
.btn.ghost:hover{background:var(--surface-2)}
.btn.lg{padding:13px 24px;font-size:1.02rem}
.btn.sq{width:52px;height:52px;padding:0;font-size:1.5rem;border-radius:12px}

/* setup */
.setup-block{display:grid;grid-template-columns:36px 1fr;gap:16px}
.setup-num{width:32px;height:32px;border-radius:50%;background:var(--accent-soft);color:var(--accent);display:grid;place-items:center;font-weight:700}
.setup-block p{color:var(--ink-2)}
.lr{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:6px 0 14px;max-width:460px}
.ear-btn{padding:16px;justify-content:space-between}
.ear-l{border-color:var(--left);color:var(--left)} .ear-l:hover{background:var(--left-soft)}
.ear-r{border-color:var(--right);color:var(--right)} .ear-r:hover{background:var(--right-soft)}
.ear-btn.playing{animation:blink .45s ease-in-out infinite alternate}
@keyframes blink{to{opacity:.55}}
.ear-tag{width:26px;height:26px;border-radius:50%;display:grid;place-items:center;background:currentColor;color:var(--surface);font-size:.8rem}
.ear-l .ear-tag{background:var(--left)} .ear-r .ear-tag{background:var(--right)}
.lr-confirm{display:flex;flex-wrap:wrap;gap:6px 18px}
.check{display:flex;align-items:center;gap:8px;cursor:pointer;font-size:.94rem;margin-top:8px}
.check input{width:18px;height:18px;accent-color:var(--accent)}
#lr-msg{margin-top:10px;padding:10px 12px;border-radius:10px;background:var(--surface-2);color:var(--ink-2)}
#cal-play .dot{width:10px;height:10px;border-radius:50%;background:var(--ink-3)}
#cal-play[aria-pressed="true"]{border-color:var(--accent);color:var(--accent)}
#cal-play[aria-pressed="true"] .dot{background:var(--accent);animation:blink .6s infinite alternate}
.opts > div > fieldset, .opts > fieldset{margin-top:14px}

/* segmented */
.seg-field{border:0;padding:0;margin:0}
.seg-field legend{font-size:.8rem;font-weight:600;text-transform:uppercase;letter-spacing:.06em;color:var(--ink-3);margin-bottom:8px;padding:0}
.seg{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:8px}
.seg label{cursor:pointer}
.seg input{position:absolute;opacity:0;pointer-events:none}
.seg span{display:flex;flex-direction:column;gap:2px;padding:12px 14px;border:1.5px solid var(--line);border-radius:10px;background:var(--surface);transition:.15s;height:100%}
.seg span small{color:var(--ink-3);font-weight:400}
.seg input:checked + span{border-color:var(--accent);background:var(--accent-soft)}
.seg input:focus-visible + span{outline:3px solid color-mix(in srgb,var(--accent) 45%,transparent);outline-offset:1px}
.seg-sm{grid-template-columns:repeat(auto-fit,minmax(110px,1fr))}
.seg-sm span{padding:9px 12px;text-align:center;align-items:center}
.seg-xs{display:flex;gap:6px;flex-wrap:wrap}
.seg-xs span{padding:6px 10px;font-size:.84rem;flex-direction:row}

.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{appearance:none;font:600 .9rem var(--font);border:1.5px solid var(--line);background:var(--surface);color:var(--ink-2);padding:8px 13px;border-radius:99px;cursor:pointer;min-height:40px;display:inline-flex;align-items:center;gap:6px}
.chip[aria-pressed="true"]{border-color:var(--accent);background:var(--accent-soft);color:var(--ink)}
.chip .mk{width:8px;height:8px;border-radius:50%;background:var(--line)}
.chip .mk.l{background:var(--left)} .chip .mk.r{background:var(--right)}

/* guided test */
.test-head{display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.now{display:flex;gap:8px}
.ear-pill,.freq-pill{font-weight:600;font-size:.9rem;padding:6px 12px;border-radius:99px}
.ear-pill{background:var(--right-soft);color:var(--right)}
.ear-pill.l{background:var(--left-soft);color:var(--left)}
.freq-pill{background:var(--surface-2);color:var(--ink-2);font-family:var(--mono);font-size:.85rem}
.prog{flex:1;min-width:120px;height:6px;border-radius:99px;background:var(--surface-2);overflow:hidden}
.prog i{display:block;height:100%;width:0;background:var(--accent);transition:width .4s}
.respond-wrap{display:flex;flex-direction:column;align-items:center;padding:48px 0 16px}
.respond{position:relative;width:min(280px,72vw);aspect-ratio:1;border-radius:50%;border:0;background:var(--accent);color:var(--accent-ink);font:700 1.6rem var(--font);cursor:pointer;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:6px;box-shadow:0 10px 40px color-mix(in srgb,var(--accent) 35%,transparent);transition:transform .08s;-webkit-tap-highlight-color:transparent;touch-action:manipulation;user-select:none}
.respond:active,.respond.hit{transform:scale(.96)}
.respond-sub{font-size:.85rem;font-weight:500;opacity:.8}
.respond-sub kbd{background:rgba(255,255,255,.2);border-color:rgba(255,255,255,.35);color:inherit}
.respond .ring{position:absolute;inset:0;border-radius:50%;border:3px solid var(--accent);opacity:0;pointer-events:none}
.respond.hit .ring{animation:ring .5s ease-out}
@keyframes ring{from{opacity:.8;transform:scale(1)}to{opacity:0;transform:scale(1.25)}}
.respond:disabled{filter:grayscale(.6);opacity:.6;cursor:default}
.status{margin-top:28px;color:var(--ink-2);min-height:1.6em;text-align:center}

/* manual */
.manual{display:grid;grid-template-columns:minmax(300px,420px) 1fr;gap:16px;align-items:start;margin-top:16px}
@media (max-width:860px){.manual{grid-template-columns:1fr}}
.m-row{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:12px 0;border-bottom:1px solid var(--line)}
.m-row:first-child{padding-top:0}
.m-row:last-of-type{border-bottom:0}
.m-row.col{flex-direction:column;align-items:stretch}
.m-row.btns{flex-wrap:wrap;justify-content:flex-start}
.m-row.btns .btn{flex:1 1 auto}
.m-lbl{font-size:.8rem;font-weight:600;text-transform:uppercase;letter-spacing:.06em;color:var(--ink-3)}
.m-lbl small{text-transform:none;letter-spacing:0;font-weight:400}
.ear-seg{flex:0 1 220px;grid-template-columns:1fr 1fr}
.ear-seg label:first-child input:checked + span{border-color:var(--left);background:var(--left-soft);color:var(--left)}
.ear-seg label:last-child input:checked + span{border-color:var(--right);background:var(--right-soft);color:var(--right)}
.level{display:flex;align-items:center;justify-content:center;gap:18px}
.level-read{display:flex;flex-direction:column;align-items:center;min-width:96px}
.level-read b{font:500 2.4rem/1 var(--mono)}
.level-read small{color:var(--ink-3)}
.meter{height:6px;border-radius:99px;background:var(--surface-2);overflow:hidden}
.meter i{display:block;height:100%;background:linear-gradient(90deg,var(--accent),#f59e0b,#dc2626);transition:width .15s}
#m-play.playing{animation:blink .45s infinite alternate}

/* chart */
.chart svg{width:100%;height:auto;display:block;font-family:var(--font)}
.chart .grid line{stroke:var(--line)}
.chart .ax text{fill:var(--ink-3);font-size:11px}
.chart .ax .t{fill:var(--ink-2);font-size:12px;font-weight:600}
.chart .band text{fill:var(--ink-3);font-size:10.5px}
.chart .s-r{stroke:var(--right);fill:none}
.chart .s-l{stroke:var(--left);fill:none}
.chart .cursor{stroke:var(--accent);stroke-dasharray:3 4}
.legend{display:flex;flex-wrap:wrap;gap:6px 18px;justify-content:center;font-size:.85rem;color:var(--ink-2);margin-top:6px}
.legend span{display:inline-flex;align-items:center;gap:6px;white-space:nowrap}
@media (max-width:520px){.card{padding:16px}.m-chart,.res-chart{padding:10px}}

/* results */
.res-head{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;flex-wrap:wrap;margin-bottom:16px}
.summary{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:16px;margin-bottom:16px}
.sum{border-left:4px solid var(--right);margin:0}
.sum.l{border-left-color:var(--left)}
.sum .who{font-size:.8rem;font-weight:600;text-transform:uppercase;letter-spacing:.06em;color:var(--right)}
.sum.l .who{color:var(--left)}
.sum .grade{font-size:1.5rem;font-weight:700;margin:4px 0 2px}
.sum .pta{color:var(--ink-2);font-size:.92rem}
.table-wrap{overflow-x:auto}
.tbl{width:100%;border-collapse:collapse;font-size:.92rem;min-width:420px}
.tbl th,.tbl td{padding:9px 8px;text-align:center;border-bottom:1px solid var(--line)}
.tbl th:first-child,.tbl td:first-child{text-align:left}
.tbl thead th{font-size:.76rem;text-transform:uppercase;letter-spacing:.05em;color:var(--ink-3);font-weight:600}
.tbl td{font-family:var(--mono);font-size:.88rem}
.tbl td:first-child{font-family:var(--font);font-weight:600}
.tbl .r{color:var(--right)} .tbl .l{color:var(--left)}
.note{border-radius:var(--r);padding:14px 18px;margin-bottom:12px;font-size:.94rem;background:var(--surface-2);color:var(--ink-2)}
.note.warn{background:var(--warn-bg);color:var(--warn-ink);border:1px solid var(--warn-line)}
.how p{color:var(--ink-2)}

.paused{position:fixed;inset:0;background:color-mix(in srgb,var(--bg) 70%,transparent);backdrop-filter:blur(4px);display:grid;place-items:center;z-index:20;padding:16px}
.paused .card{max-width:360px;text-align:center}

.foot{padding:24px 16px 40px;color:var(--ink-3);font-size:.82rem;border-top:1px solid var(--line)}

@media print{
  .top,.foot,.no-print,.how .hint{display:none!important}
  body{background:#fff}
  .card{box-shadow:none;break-inside:avoid}
}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}