:root{
  --bg:#F6F4EE; --ink:#1B2A41; --muted:#475569; --card:#fff; --line:#C9D1DC;
  --accent:#0B6E6E; --accent-d:#085757; --soft:#E4F0EE; --good:#1E7B3A; --hint:#D99A00; --focus:#1D4ED8;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:500 22px/1.45 -apple-system,"SF Pro Text","Segoe UI",Verdana,sans-serif;touch-action:manipulation}
h1,h2{line-height:1.2;margin:0 0 .4em}
h1{font-size:1.9rem}h2{font-size:1.6rem}
a{color:var(--accent-d)}
#view:focus{outline:none}
:focus-visible{outline:4px solid var(--focus);outline-offset:3px;border-radius:10px}
.wrap{max-width:1100px;margin:0 auto;padding:20px}
.card{background:var(--card);border:2px solid var(--line);border-radius:22px}
.pad{padding:24px}
.small{font-size:.8rem;color:var(--muted);margin:.4em 0}

/* buttons: large touch targets */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:68px;min-width:68px;padding:0 26px;border-radius:18px;border:3px solid var(--accent);background:#fff;color:var(--accent-d);font:700 1.05rem/1.2 inherit;text-decoration:none;cursor:pointer}
.btn:disabled{opacity:.45;cursor:default}
.btn.primary{background:var(--accent);color:#fff}
.btn.primary:hover:not(:disabled){background:var(--accent-d)}
.btn.ghost{border-color:var(--line);color:var(--ink)}
.btn.on,.btn[aria-pressed=true].pick{background:var(--soft)}
.btn.pick.on{background:var(--accent);color:#fff}
.small-btn{min-height:56px;font-size:.9rem;padding:0 18px}
.big-btn{min-height:84px;font-size:1.3rem;padding:0 40px}

/* top bar */
.topbar{background:#fff;border-bottom:2px solid var(--line)}
.topbar .wrap{display:flex;flex-wrap:wrap;align-items:center;gap:12px;padding-top:12px;padding-bottom:12px}
.topbar h1{margin:0;font-size:1.35rem;flex:1 1 220px}
.tools{display:flex;flex-wrap:wrap;gap:10px}
.modes{display:flex;gap:12px;margin:18px 0}
.modes .btn{flex:1;min-height:76px;font-size:1.3rem}

/* home */
.hero{text-align:center;padding:36px 20px 10px}
.hero h1{font-size:2.6rem}
.hero p{font-size:1.2rem;max-width:34em;margin:.5em auto 1.2em}
.sign-row{display:flex;gap:18px;justify-content:center;flex-wrap:wrap;margin:26px 0}
.sign-row .sign{width:104px;height:auto}
.lesson-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:20px}
.lesson-card{padding:24px;display:flex;flex-direction:column;gap:12px}
.lesson-card .sign-row{margin:6px 0;justify-content:flex-start;gap:10px}
.lesson-card .sign-row .sign{width:68px}
.lesson-card.soon{background:transparent;border-style:dashed;color:var(--muted)}
.foot{margin:34px 0 10px;padding:18px 22px;border-radius:18px;background:var(--soft);font-size:.85rem}

/* signs */
.sign{display:block;width:100%;height:auto}
.sign-btn{background:none;border:0;padding:0;cursor:pointer;position:relative;border-radius:16px;-webkit-tap-highlight-color:transparent}
.sign-btn::before{content:"";position:absolute;inset:-8px}           /* larger hit area */
.sign-btn.tried{opacity:.38}
.sign-btn.hint{outline:7px solid var(--hint);outline-offset:6px}      /* steady, not flashing */
.sign-btn.correct{outline:7px solid var(--good);outline-offset:6px}
.sign-btn.correct::after{content:"\2713";position:absolute;right:-14px;top:-14px;width:46px;height:46px;border-radius:50%;background:var(--good);color:#fff;font:900 30px/46px sans-serif;text-align:center}
.pop{animation:gentle-pop .6s ease-out 1}
@keyframes gentle-pop{0%{transform:scale(1)}50%{transform:scale(1.06)}100%{transform:scale(1)}}
.appear{animation:fade-in .45s ease-out 1}
@keyframes fade-in{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

/* learn */
.learn{display:grid;grid-template-columns:minmax(220px,360px) 1fr;gap:28px;padding:28px}
.learn-sign{display:flex;flex-direction:column;align-items:center;gap:16px}
.sign-btn.big{width:100%;max-width:340px}
.sign-btn.mini{width:96px}
.pair{display:flex;align-items:center;gap:14px;font-size:.85rem;color:var(--muted)}
.kicker{margin:0;color:var(--muted);font-size:.8rem;text-transform:uppercase;letter-spacing:.06em}
.sign-name{font-size:2.2rem}
.meaning{font-size:1.25rem}
.safety{background:#FFF6DB;border:2px solid #E3C766;border-radius:14px;padding:14px 18px;font-size:1rem}
.learn-nav{grid-column:1/-1;display:flex;align-items:center;justify-content:space-between;gap:14px;flex-wrap:wrap}
.dots{display:flex;gap:8px;flex-wrap:wrap;justify-content:center}
.dot{width:44px;height:44px;border-radius:50%;background:#fff;border:3px solid var(--accent);padding:0;cursor:pointer;position:relative}
.dot[aria-current=true]{background:var(--accent)}
.demo{margin:14px 0 8px}.demo svg{width:100%;height:auto;border-radius:14px;border:2px solid var(--line);display:block}
.demo figcaption{font-size:.8rem;color:var(--muted);margin-top:6px}
.demo-car{animation:drive 4.5s ease-out 1 both}
@keyframes drive{from{transform:translateX(-280px)}to{transform:translateX(0)}}

/* practice */
.scene-picker{display:flex;flex-wrap:wrap;gap:12px;margin-bottom:16px}
.prompt{text-align:center;margin:8px 0 16px}
.prompt-text{font-size:2rem;font-weight:800;margin:0}
.choices{display:flex;gap:34px;justify-content:center;flex-wrap:wrap;padding:20px 0}
.choice-wrap{display:flex;flex-direction:column;align-items:center;gap:10px;width:min(30%,260px);min-width:150px}
.choice-wrap .sign-btn{width:100%}
.caption{display:none;font-size:.85rem;font-weight:700}
.show-captions .caption{display:block}
.scene{position:relative;aspect-ratio:16/9;width:100%;max-width:1000px;margin:0 auto;border-radius:22px;overflow:hidden;border:3px solid var(--line);background:#fff}
.scene>svg{position:absolute;inset:0;width:100%;height:100%}
.scene .sign-btn.in-scene{position:absolute;display:block;min-width:84px}
.scene .pole{position:absolute;width:.9%;min-width:5px;transform:translateX(-50%);background:#6B7280;border-radius:3px}
.feedback{min-height:3.2em;text-align:center;font-size:1.15rem;margin:14px auto 6px;max-width:40em}
.actions{text-align:center;min-height:90px}

/* wordy things hidden when Words are off (narration still plays) */
.no-words .wordy{display:none}

/* dialog */
dialog{max-height:92vh;overflow:auto;border:3px solid var(--accent);border-radius:22px;padding:0;max-width:min(640px,94vw);width:100%;color:var(--ink);background:#fff}
dialog::backdrop{background:rgba(27,42,65,.5)}
.td{padding:24px;font-size:1rem}
.td fieldset{border:2px solid var(--line);border-radius:14px;margin:0 0 14px;padding:10px 16px 14px}
.td legend{font-weight:800;padding:0 8px}
.td label{display:flex;align-items:center;gap:12px;min-height:48px}
.td input[type=checkbox],.td input[type=radio]{width:26px;height:26px;accent-color:var(--accent)}
.td input[type=range]{flex:1;height:34px}
.td-actions{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap}

/* motion: reduced / paused */
html.paused *,html.paused *::before,html.paused *::after{animation-play-state:paused!important}
html.reduce-motion *,html.reduce-motion *::before,html.reduce-motion *::after{animation:none!important;transition:none!important}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important}}

@media (max-width:760px){
  body{font-size:20px}
  .learn{grid-template-columns:1fr;padding:18px}
  .hero h1{font-size:2rem}
  .prompt-text{font-size:1.5rem}
  .choices{gap:18px}
}

/* Teacher button: press-and-hold progress fill */
.hold-btn{position:relative;overflow:hidden;-webkit-touch-callout:none;-webkit-user-select:none;user-select:none}
.hold-btn::after{content:"";position:absolute;left:0;bottom:0;height:6px;width:0;background:var(--accent)}
.hold-btn.holding::after{width:100%;transition:width 1.5s linear}

/* Shown only when a phone blocks sound until the first tap */
.tap-hint{position:fixed;left:50%;bottom:22px;transform:translateX(-50%);z-index:20;background:var(--ink);color:#fff;padding:16px 28px;border-radius:999px;font-weight:700;font-size:1rem;box-shadow:0 4px 18px rgba(0,0,0,.25);max-width:92vw;text-align:center}