:root{
  --bg1:#0f8e76;
  --bg2:#0b6658;
  --bg3:#07463f;
  --panel:#055246;
  --panel-deep:#04463c;
  --cream1:#fffaf1;
  --cream2:#f4eadb;
  --tile-border:#cb8f6f;
  --tile-shadow:#7d4d3b;
  --gold:#f8d46f;
  --purple:#ca4fff;
  --purple-dark:#42104f;
  --text:#0f2f3c;
}
*{box-sizing:border-box}
html,body{margin:0;min-height:100%}
body{
  font-family:system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;
  background:linear-gradient(180deg,var(--bg1),var(--bg2) 45%,var(--bg3));
  color:#f8fffb;
}
button{font:inherit;cursor:pointer}
button:disabled{cursor:not-allowed}
.app-shell{max-width:760px;margin:0 auto;padding:16px 14px 34px}
.topbar{display:flex;align-items:flex-start;justify-content:space-between;gap:12px}
.circle-btn{
  width:54px;height:54px;border-radius:50%;border:2px solid #a96e39;
  background:linear-gradient(180deg,#b9772f,#7f431f);color:#ffebbf;font-size:26px;
  box-shadow:0 4px 0 #492415;
}
.brand-wrap{text-align:center;flex:1}
.brand-wrap h1{margin:0;color:#ffde86;font-size:clamp(29px,5vw,42px);line-height:1.05;text-shadow:0 2px 0 #613616}
.brand-wrap p{margin:6px 0 0;color:#d6f0e5;font-weight:600}
.lang-btn{
  border:0;border-radius:14px;padding:12px 18px;background:#ead7ac;color:#4c3316;
  font-weight:800;box-shadow:0 3px 0 #9a8460;
}
.quick-nav{display:flex;justify-content:center;gap:10px;flex-wrap:wrap;margin:14px 0 18px}
.nav-pill,.status-pill{
  background:#0a564a;border:1.5px solid #8fc7b4;border-radius:999px;color:#fff7d9;
  padding:10px 16px;font-weight:800;box-shadow:0 2px 0 rgba(0,0,0,.18)
}
.status-row{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:10px}
.status-pill{min-width:120px;text-align:center}
.status-pill.center{min-width:82px}
.mission{text-align:center;color:#e8fff6;font-weight:600;min-height:28px;margin:10px 0 14px;line-height:1.4}
.board-panel{
  background:radial-gradient(circle at center,#0a6256 0,#064d44 60%,#03453d 100%);
  border:2px solid #68d8bf;border-radius:28px;box-shadow:inset 0 0 22px rgba(0,0,0,.34),0 8px 18px rgba(0,0,0,.18);
  padding:26px 18px;min-height:420px;display:flex;align-items:center;justify-content:center;
}
.board{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;max-width:500px;width:100%}
.tile{
  position:relative;min-height:78px;border-radius:14px;border:2px solid var(--tile-border);
  border-bottom:6px solid var(--tile-shadow);background:linear-gradient(180deg,var(--cream1),var(--cream2));
  color:var(--text);font-weight:850;font-size:clamp(12px,1.7vw,18px);line-height:1.18;padding:10px 7px;
  box-shadow:0 4px 8px rgba(0,0,0,.28);display:flex;align-items:center;justify-content:center;text-align:center;
  overflow-wrap:anywhere;transition:transform .12s ease,filter .12s ease,opacity .12s ease;
}
.tile:hover:not(:disabled){transform:translateY(-2px)}
.tile::before{content:attr(data-symbol);position:absolute;top:7px;left:9px;font-size:15px;opacity:.9}
.tile.selected{outline:3px solid #ffd85b;transform:translateY(-2px)}
.tile.hinted{outline:4px solid #ffdd68}
.tile.done{visibility:hidden;pointer-events:none}
.tile.wrong{background:linear-gradient(180deg,#ffe6de,#ffcdc1);border-color:#db8a79}
.tray-wrap{display:flex;justify-content:center;margin:18px 0 16px}
.tray{
  width:min(540px,100%);display:grid;grid-template-columns:repeat(2,1fr);gap:4px;
  background:linear-gradient(180deg,#71148c,#310538);padding:8px;border-radius:22px;
  box-shadow:0 0 0 4px rgba(230,84,255,.35),0 0 20px rgba(228,96,255,.22);
}
.tray-slot{
  min-height:68px;border-radius:12px;background:rgba(17,1,29,.55);border:1px solid rgba(255,170,255,.28);
  display:flex;align-items:center;justify-content:center;text-align:center;padding:8px 10px;font-weight:800;color:#f5d9ff
}
.tray-slot.filled{background:rgba(108,26,127,.72);color:#fff3fb}
.action-row{display:flex;justify-content:center;gap:18px;flex-wrap:wrap}
.action-btn{
  min-width:102px;padding:18px 16px 16px;border-radius:20px;border:2px solid #f1c37f;color:#fff8e9;
  font-weight:900;box-shadow:0 5px 0 rgba(93,53,18,.95);
}
.action-shuffle,.action-hint{background:linear-gradient(180deg,#be7a2e,#8f5321)}
.action-undo{background:linear-gradient(180deg,#66744c,#4e5d39);border-color:#8fa07a;color:#dbe5d1;box-shadow:0 5px 0 #36422a}
.action-btn:disabled{opacity:.45}
.feedback{min-height:30px;text-align:center;margin:16px auto 10px;font-weight:800;line-height:1.45}
.feedback.good{color:#d8ffe3}.feedback.bad{color:#ffd8ca}
.learn-card{margin:0 auto;background:#fff8e4;color:#173d35;border:2px solid #e0c16e;border-radius:16px;padding:14px 16px;line-height:1.55;max-width:640px}
.learn-card[hidden]{display:none}
.learn-tag{display:block;color:#8d611d;font-weight:900;margin-bottom:6px}
.learn-example{margin-top:4px;color:#33574c}
.overlay{position:fixed;inset:0;background:rgba(0,18,15,.8);display:flex;align-items:center;justify-content:center;padding:16px;z-index:99}
.hidden{display:none}
.modal{position:relative;width:min(560px,100%);max-height:88vh;overflow:auto;background:#fffaf1;color:#143931;border-radius:18px;padding:22px;box-shadow:0 16px 46px rgba(0,0,0,.36)}
.close{position:absolute;top:10px;right:10px;border:0;background:#ece2d3;padding:8px 11px;border-radius:11px}
.modal input{width:100%;display:block;margin:9px 0;padding:12px;border-radius:10px;border:1px solid #b7c7c0}
.primary,.secondary{margin:8px 8px 8px 0;padding:12px 14px;border-radius:12px;font-weight:800;border:1px solid transparent}
.primary{background:#0f7664;color:white}.secondary{background:#dae8e2;color:#12392f}
.topics{display:grid;grid-template-columns:1fr 1fr;gap:8px}.topics button{padding:13px 8px;background:#ebf6f0;border:1px solid #afd0bf;color:#163f35;border-radius:10px;font-weight:800}.topics small{display:block;font-size:11px;margin-top:5px;color:#527067}.pair-detail{padding:10px 0;border-bottom:1px solid #d8e0dc}.pair-detail div,.note{font-size:13px;color:#56726d}
@media (max-width:640px){
  .topbar{align-items:center}
  .brand-wrap h1{font-size:32px}
  .board-panel{padding:18px 10px;min-height:360px}
  .board{gap:10px}
  .tile{min-height:72px;font-size:13px}
}
@media (max-width:480px){
  .app-shell{padding:12px 8px 24px}
  .circle-btn{width:46px;height:46px;font-size:23px}
  .lang-btn{padding:10px 13px;font-size:14px}
  .nav-pill,.status-pill{padding:9px 12px;font-size:14px;min-width:auto}
  .status-row{gap:8px}
  .board{grid-template-columns:repeat(3,1fr);max-width:355px}
  .tile{min-height:68px;padding:9px 5px;font-size:12px;border-bottom-width:5px}
  .tile::before{font-size:13px;top:6px;left:7px}
  .tray-slot{min-height:58px;font-size:13px}
  .action-row{gap:12px}
  .action-btn{min-width:92px;padding:15px 10px;border-radius:18px;font-size:15px}
  .topics{grid-template-columns:1fr}
}
@media (prefers-reduced-motion:reduce){.tile{transition:none}}

/* Long literary titles are kept readable without shrinking entire board */
.tile{hyphens:auto;word-break:normal;overflow-wrap:break-word;padding-left:8px;padding-right:8px;font-size:clamp(11px,1.5vw,16px)}
@media(max-width:480px){.tile{font-size:11px;line-height:1.2;min-height:80px}}