/* Phone Speaker Cleaner — design system v3 (modern, theme-aware light/dark, water-brand). */
:root{
  /* light (default) */
  --bg:#f5f7fe; --bg2:#eef1fb; --surface:#ffffff; --elev:#ffffff;
  --ink:#0f172a; --muted:#51607a; --dim:#94a3b8; --line:#e5e9f5; --line2:#d7ddef;
  --brand:#4f46e5; --brand2:#0ea5e9; --brand3:#06b6d4; --accent:#6366f1;
  --good:#10b981; --warn:#f59e0b; --bad:#ef4444;
  --grad:linear-gradient(103deg,#6366f1,#0ea5e9 55%,#06b6d4);
  --grad-soft:linear-gradient(180deg,rgba(99,102,241,.10),rgba(14,165,233,.05));
  --ring:rgba(15,23,42,.06);
  --shadow:0 20px 50px -18px rgba(30,41,120,.28); --shadow-sm:0 8px 24px -10px rgba(30,41,120,.22);
  --radius:22px; --radius-sm:14px; --measure:47rem; --wide:76rem;
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Inter,system-ui,sans-serif;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --bg:#0a0f1f; --bg2:#0f1730; --surface:#141d38; --elev:#18224a;
    --ink:#eef2ff; --muted:#a3b1d6; --dim:#697aa3; --line:#24304f; --line2:#31406a;
    --brand:#818cf8; --brand2:#38bdf8; --brand3:#22d3ee; --accent:#818cf8;
    --grad:linear-gradient(103deg,#818cf8,#38bdf8 55%,#22d3ee);
    --grad-soft:linear-gradient(180deg,rgba(129,140,248,.14),rgba(56,189,248,.05));
    --ring:rgba(255,255,255,.07);
    --shadow:0 24px 60px -20px rgba(0,0,0,.6); --shadow-sm:0 10px 30px -12px rgba(0,0,0,.5);
  }
}
:root[data-theme="dark"]{
  --bg:#0a0f1f; --bg2:#0f1730; --surface:#141d38; --elev:#18224a;
  --ink:#eef2ff; --muted:#a3b1d6; --dim:#697aa3; --line:#24304f; --line2:#31406a;
  --brand:#818cf8; --brand2:#38bdf8; --brand3:#22d3ee; --accent:#818cf8;
  --grad:linear-gradient(103deg,#818cf8,#38bdf8 55%,#22d3ee);
  --grad-soft:linear-gradient(180deg,rgba(129,140,248,.14),rgba(56,189,248,.05));
  --ring:rgba(255,255,255,.07);
  --shadow:0 24px 60px -20px rgba(0,0,0,.6); --shadow-sm:0 10px 30px -12px rgba(0,0,0,.5);
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;font-family:var(--font);background:var(--bg);color:var(--ink);line-height:1.65;
  background-image:radial-gradient(1200px 620px at 50% -12%,rgba(99,102,241,.14),transparent 62%),radial-gradient(760px 460px at 88% 4%,rgba(6,182,212,.10),transparent 60%);
  background-attachment:fixed;-webkit-font-smoothing:antialiased}
a{color:var(--brand);text-decoration:none}a:hover{text-decoration:underline}
img{max-width:100%;height:auto;display:block}
.wrap{max-width:var(--measure);margin:0 auto;padding:0 1.15rem}
.wide{max-width:var(--wide)}
h1,h2,h3{line-height:1.12;letter-spacing:-.025em;margin:.2em 0 .4em;color:var(--ink)}
h1{font-size:clamp(2.1rem,6.2vw,3.6rem);font-weight:850}
h2{font-size:clamp(1.55rem,3.8vw,2.2rem);font-weight:820}
h3{font-size:1.22rem;font-weight:760}
.sub{color:var(--muted);font-size:clamp(1.06rem,2.4vw,1.28rem);max-width:40rem;margin-inline:auto}
.eyebrow{display:inline-block;text-transform:uppercase;letter-spacing:.13em;font-size:.72rem;font-weight:800;color:var(--brand);background:var(--grad-soft);border:1px solid var(--line2);padding:.35rem .8rem;border-radius:999px;margin-bottom:.7rem}
.grad{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
section{padding:2.4rem 0}
.center{text-align:center}

/* header */
.site-head{position:sticky;top:0;z-index:40;background:color-mix(in srgb,var(--bg) 82%,transparent);backdrop-filter:blur(14px);border-bottom:1px solid var(--line)}
.site-head .wrap{display:flex;align-items:center;gap:1rem;justify-content:space-between;min-height:62px}
.brand{display:flex;align-items:center;gap:.55rem;font-weight:850;color:var(--ink);font-size:1.05rem;letter-spacing:-.02em;white-space:nowrap;flex:0 0 auto}
.brand:hover{text-decoration:none}
.brand .dot{width:30px;height:30px;border-radius:9px;background:var(--grad);display:grid;place-items:center;box-shadow:0 6px 16px -4px rgba(79,70,229,.5);flex:0 0 auto}
.brand .dot::after{content:"";width:12px;height:12px;border:2.5px solid #fff;border-radius:50%}
.nav{display:flex;align-items:center;flex-wrap:nowrap;gap:.2rem}
.nav a{color:var(--muted);margin-left:.9rem;font-size:.93rem;font-weight:650;white-space:nowrap}
.nav a:hover{color:var(--ink);text-decoration:none}
.theme-toggle{margin-left:.9rem;width:36px;height:36px;border-radius:10px;border:1px solid var(--line2);background:var(--surface);color:var(--ink);cursor:pointer;font-size:1rem;display:grid;place-items:center;flex:0 0 auto}
.theme-toggle:hover{border-color:var(--brand)}
@media(max-width:820px){.nav a.hide-md{display:none}}
@media(max-width:560px){.brand{font-size:.95rem}.nav a.hide-sm{display:none}.nav a{margin-left:.7rem;font-size:.86rem}}
@media(max-width:400px){.nav a{display:none}.theme-toggle{margin-left:.4rem}}

/* hero */
.hero{position:relative;text-align:center;padding:2.8rem 0 .6rem;overflow:hidden}
.hero .rings{position:absolute;top:-30px;left:50%;transform:translateX(-50%);width:680px;max-width:150vw;aspect-ratio:1;pointer-events:none;opacity:.55;z-index:0}
.hero .rings span{position:absolute;inset:0;margin:auto;border:1.5px solid color-mix(in srgb,var(--brand) 45%,transparent);border-radius:50%;animation:ripple 4.2s ease-out infinite}
.hero .rings span:nth-child(2){animation-delay:1.4s}.hero .rings span:nth-child(3){animation-delay:2.8s}
@keyframes ripple{0%{width:70px;height:70px;opacity:.75}100%{width:680px;height:680px;opacity:0}}
.hero>*{position:relative;z-index:1}
.trust-bar{display:flex;gap:.5rem;justify-content:center;flex-wrap:wrap;margin:1.1rem 0 .2rem}
.trust-bar span{display:inline-flex;align-items:center;gap:.35rem;background:var(--surface);border:1px solid var(--line);border-radius:999px;padding:.4rem .85rem;font-size:.83rem;color:var(--muted);font-weight:650;box-shadow:var(--shadow-sm)}
.trust-bar b{color:var(--good)}

/* the tool */
.tool{position:relative;background:var(--elev);border:1px solid var(--line);
  border-radius:var(--radius);padding:1.5rem;margin:1.5rem auto;max-width:35rem;box-shadow:var(--shadow)}
.tool::before{content:"";position:absolute;inset:-1px;border-radius:var(--radius);padding:1.5px;background:var(--grad);
  -webkit-mask:linear-gradient(#000 0 0) content-box,linear-gradient(#000 0 0);-webkit-mask-composite:xor;mask-composite:exclude;opacity:.55;pointer-events:none}
.psc-modes{display:grid;grid-template-columns:repeat(3,1fr);gap:.55rem;margin-bottom:.9rem}
.psc-mode{background:var(--bg2);color:var(--muted);border:1px solid var(--line);border-radius:var(--radius-sm);
  padding:.65rem .4rem;font-weight:700;cursor:pointer;font-size:.85rem;transition:.18s;display:flex;flex-direction:column;align-items:center;gap:.25rem}
.psc-mode .em{font-size:1.25rem}
.psc-mode:hover{border-color:var(--line2)}
.psc-mode.is-active{background:var(--grad-soft);color:var(--brand);border-color:var(--brand);box-shadow:0 0 0 1px var(--brand) inset}
.psc-mode-desc{color:var(--muted);text-align:center;min-height:1.4em;margin:.1rem 0 .9rem;font-size:.93rem}
.psc-stage{position:relative;display:grid;place-items:center;margin:.5rem auto 1.1rem;width:210px;height:210px}
.psc-ring{transform:rotate(-90deg);position:absolute;inset:0}
.psc-ring circle{fill:none;stroke-width:9}
.psc-ring .bg{stroke:var(--ring)}
.psc-ring .fg{stroke:url(#pscgrad);stroke-linecap:round;transition:stroke-dashoffset .25s linear}
.psc-stage .center-btn{position:absolute;inset:0;margin:auto;width:132px;height:132px;border-radius:50%;border:0;cursor:pointer;
  color:#fff;background:var(--grad);font-weight:850;font-size:1rem;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:.15rem;
  box-shadow:0 14px 34px -8px rgba(79,70,229,.55);transition:transform .15s}
.psc-stage .center-btn:active{transform:scale(.96)}
.psc-running .center-btn{background:linear-gradient(180deg,#fb7185,#ef4444);box-shadow:0 14px 40px -8px rgba(239,68,68,.6);animation:pulse 1.6s ease-in-out infinite}
.psc-done .center-btn{background:linear-gradient(180deg,#34d399,#10b981);box-shadow:0 14px 40px -8px rgba(16,185,129,.55)}
@keyframes pulse{0%,100%{box-shadow:0 14px 34px -8px rgba(239,68,68,.4)}50%{box-shadow:0 14px 48px -6px rgba(239,68,68,.75)}}
.center-btn .big{font-size:1.7rem;line-height:1}
.center-btn small{font-weight:750;opacity:.92;font-size:.72rem}
.psc-viz{width:100%;height:66px;display:block;margin:.2rem 0 1rem;border-radius:12px;background:var(--bg2);border:1px solid var(--line)}
.psc-freq-wrap{margin:.5rem 0}
.psc-freq-wrap label{display:flex;justify-content:space-between;color:var(--muted);font-size:.88rem;margin-bottom:.4rem;font-weight:650}
.psc-freq-wrap output{color:var(--brand);font-variant-numeric:tabular-nums;font-weight:700}
.psc-freq{width:100%;accent-color:var(--brand);height:6px}
.psc-freq-live{color:var(--brand3);font-weight:700;font-variant-numeric:tabular-nums}
.psc-clarity{margin-top:1.1rem;background:var(--bg2);border:1px solid var(--line);border-radius:var(--radius-sm);padding:.95rem 1rem}
.psc-clarity .row{display:flex;align-items:center;justify-content:space-between;gap:.6rem;flex-wrap:wrap}
.psc-measure{background:var(--surface);border:1px solid var(--line2);color:var(--ink);border-radius:10px;padding:.65rem 1rem;font-weight:700;cursor:pointer;font-size:.92rem}
.psc-measure:hover{border-color:var(--brand)} .psc-measure:disabled{opacity:.55}
.psc-meter{height:11px;border-radius:999px;background:var(--ring);overflow:hidden;margin-top:.75rem}
.psc-meter i{display:block;height:100%;width:0;border-radius:999px;background:linear-gradient(90deg,#ef4444,#f59e0b,#10b981);transition:width .8s cubic-bezier(.2,.8,.2,1)}
.psc-score-out{color:var(--good);font-weight:800;font-variant-numeric:tabular-nums}
.psc-note{color:var(--dim);font-size:.8rem;margin-top:1rem;text-align:center;line-height:1.5}

/* scenario chooser */
.scenarios{display:grid;grid-template-columns:repeat(3,1fr);gap:.7rem;margin:1rem auto;max-width:35rem}
.scenario{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);padding:1rem .6rem;text-align:center;cursor:pointer;transition:.18s;color:var(--ink);box-shadow:var(--shadow-sm)}
.scenario:hover{border-color:var(--brand);transform:translateY(-3px);text-decoration:none}
.scenario .em{font-size:1.7rem;display:block;margin-bottom:.3rem}
.scenario small{color:var(--muted);display:block;font-size:.78rem}
@media(max-width:520px){.scenarios,.psc-modes{gap:.5rem}}

/* sections */
.eyebrow-h{text-align:center;margin-bottom:1.5rem}
.steps{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:1rem;margin:1.3rem 0}
.step{position:relative;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);padding:1.2rem;box-shadow:var(--shadow-sm)}
.step .n{width:36px;height:36px;border-radius:11px;background:var(--grad);color:#fff;font-weight:850;display:grid;place-items:center;margin-bottom:.6rem}
.step b{display:block;margin-bottom:.2rem}
.step p{color:var(--muted);font-size:.94rem;margin:0}
.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:1.5rem;align-items:center}
@media(max-width:760px){.grid-2{grid-template-columns:1fr}}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(160px,1fr));gap:.85rem;margin:1rem 0}
.card{display:block;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);padding:1.05rem;color:var(--ink);box-shadow:var(--shadow-sm);transition:.18s}
.card:hover{border-color:var(--brand);transform:translateY(-3px);text-decoration:none}
.card .em{font-size:1.5rem}
.card b{display:block;margin:.35rem 0 .1rem}
.card small{color:var(--muted)}
.stat-row{display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:.85rem;margin:1.3rem 0}
.stat{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);padding:1.1rem;text-align:center;box-shadow:var(--shadow-sm)}
.stat b{display:block;font-size:1.8rem;font-weight:850;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.stat small{color:var(--muted)}
.cmp{width:100%;border-collapse:collapse;margin:1rem 0;font-size:.94rem;overflow:hidden;border-radius:var(--radius-sm);border:1px solid var(--line);background:var(--surface)}
.cmp th,.cmp td{padding:.75rem .85rem;text-align:left;border-bottom:1px solid var(--line)}
.cmp thead th{background:var(--bg2);color:var(--muted);font-size:.8rem;text-transform:uppercase;letter-spacing:.05em}
.cmp tbody tr:last-child td{border-bottom:0}
.cmp tbody tr:hover{background:var(--grad-soft)}
.cmp .yes{color:var(--good);font-weight:700}.cmp .no{color:var(--bad)}.cmp .mid{color:var(--warn)}
.cmp .feat{font-weight:700}
.cmp-scroll{overflow-x:auto}
.diagram{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:1.3rem;box-shadow:var(--shadow-sm)}
.callout{background:var(--grad-soft);border:1px solid var(--line2);border-left:3px solid var(--brand);border-radius:var(--radius-sm);padding:1.05rem 1.2rem;margin:1.4rem 0}
.callout.warn{border-left-color:var(--warn);background:linear-gradient(180deg,rgba(245,158,11,.10),transparent)}
.prose p,.prose li{color:var(--ink)}.prose h2{margin-top:1.6em}.prose ul{padding-left:1.2rem}.prose a{font-weight:600}
.faq details{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);padding:.2rem 1.15rem;margin:.65rem 0;box-shadow:var(--shadow-sm);transition:.18s}
.faq details[open]{border-color:var(--line2)}
.faq summary{cursor:pointer;font-weight:760;padding:.9rem 0;list-style:none;display:flex;justify-content:space-between;gap:1rem;color:var(--ink)}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";color:var(--brand);font-weight:800;font-size:1.35rem;line-height:1}
.faq details[open] summary::after{content:"–"}
.faq details p{color:var(--muted);margin-top:0}
.sticky-cta{position:fixed;left:0;right:0;bottom:0;z-index:50;display:none;padding:.6rem .9rem;background:color-mix(in srgb,var(--bg) 92%,transparent);backdrop-filter:blur(12px);border-top:1px solid var(--line2)}
.sticky-cta a{display:block;text-align:center;background:var(--grad);color:#fff;font-weight:850;padding:.85rem;border-radius:14px;box-shadow:var(--shadow-sm)}
.sticky-cta a:hover{text-decoration:none}
@media(max-width:760px){.sticky-cta{display:block}body{padding-bottom:4.6rem}}
.site-foot{border-top:1px solid var(--line);margin-top:3rem;padding:2.4rem 0;color:var(--muted);font-size:.92rem;background:var(--surface)}
.site-foot h4{color:var(--ink);font-size:.85rem;text-transform:uppercase;letter-spacing:.08em;margin:0 0 .6rem}
.site-foot a{color:var(--muted);display:inline-block;margin:.3rem .8rem .3rem 0}
.site-foot a:hover{color:var(--brand)}
.site-foot .fine{opacity:.7;font-size:.82rem;margin-top:1.4rem}

/* speaker & mic test */
#psc-test .pt-block{padding:1.05rem 0;border-bottom:1px solid var(--line)}
#psc-test .pt-block:last-of-type{border-bottom:0}
#psc-test h3{margin:.1rem 0 .7rem;font-size:1.05rem}
.pt-stereo{display:flex;gap:.6rem;margin-bottom:.7rem}
.pt-chan{flex:1;text-align:center;padding:.95rem;border-radius:var(--radius-sm);border:1px solid var(--line);background:var(--bg2);color:var(--muted);font-weight:700;transition:.15s}
.pt-chan.lit{border-color:var(--brand);color:var(--brand);background:var(--grad-soft);box-shadow:0 0 22px -6px var(--brand)}
.pt-chan span{color:var(--brand)}
.pt-row{display:flex;gap:.5rem;flex-wrap:wrap}
.pt-btn{flex:1;min-width:92px;background:var(--surface);border:1px solid var(--line2);color:var(--ink);border-radius:11px;padding:.72rem .8rem;font-weight:700;cursor:pointer;font-size:.9rem;transition:.15s}
.pt-btn:hover{border-color:var(--brand)}
.pt-btn.is-on{background:var(--grad);color:#fff;border-color:transparent}
.pt-out{color:var(--muted);font-size:.9rem;margin:.7rem 0 0;min-height:1.3em}
.pt-mic-bar{margin:.7rem 0 0}.pt-mic-bar i{background:linear-gradient(90deg,var(--brand),var(--good))}

/* hearing screening */
#psc-hearing .ph-disclaimer{background:linear-gradient(180deg,rgba(245,158,11,.12),transparent);border:1px solid var(--line2);border-left:3px solid var(--warn);border-radius:11px;padding:.75rem .95rem;font-size:.85rem;color:var(--muted);margin-bottom:1rem}
#psc-hearing .ph-disclaimer strong{color:var(--ink)}
.ph-readout{display:flex;gap:.5rem;justify-content:space-between;align-items:center;flex-wrap:wrap;margin:.6rem 0;font-weight:700}
.ph-ear{padding:.32rem .75rem;border-radius:999px;border:1px solid var(--line2);font-size:.85rem}
.ph-ear.left{color:var(--brand)} .ph-ear.right{color:var(--brand3)}
.ph-freq{font-size:1.45rem;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.ph-step{color:var(--muted);font-size:.85rem;font-weight:600}
.ph-progress{margin:.4rem 0}.ph-progress i{background:var(--grad)}
.ph-b{font-size:.8rem}.ph-b.good{color:var(--good)}.ph-b.mid{color:var(--warn)}.ph-b.low{color:var(--bad)}.ph-b.none{color:var(--dim)}

/* embed */
.embed-attr{text-align:center;margin:12px auto 2px;font-size:.85rem}
.embed-attr a{color:var(--brand);font-weight:700}