/* ============================================================
   Periodic Bubbles - app stylesheet (no framework, mobile-first)
   ============================================================ */
:root{
  --bg:#0b0e14;
  --panel:#141926;
  --panel-2:#1b2233;
  --line:#2a3348;
  --txt:#e8edf6;
  --muted:#93a0b8;
  --accent:#ffc107;
  --accent-2:#4b88a2;
  --good:#34d17c;
  --bad:#ef5350;
  --radius:6px;
  --bar-h:56px;
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html{scroll-behavior:smooth}
#bubbles,#collection,#browse,#support{scroll-margin-top:64px}
html,body{height:100%}
body{
  margin:0;background:var(--bg);color:var(--txt);
  font-family:'Fira Sans',system-ui,-apple-system,'Segoe UI',Roboto,Arial,sans-serif;
  display:flex;flex-direction:column;min-height:100dvh;
}

/* ---------- Top bar ---------- */
.topbar{
  position:sticky;top:0;z-index:30;
  display:flex;align-items:center;gap:10px;flex-wrap:wrap;
  padding:8px 12px;background:rgba(11,14,20,.86);backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
}
.brand{display:flex;align-items:baseline;gap:8px}
.brand h1{font-size:18px;margin:0;letter-spacing:.3px}
.brand .tag{font-size:11px;color:var(--muted);display:none}
@media(min-width:640px){.brand .tag{display:inline}}

.sectnav{display:flex;gap:2px;margin-left:6px}
.sectnav a{
  display:inline-flex;align-items:center;gap:6px;padding:7px 10px;border-radius:4px;
  color:var(--muted);text-decoration:none;font-size:12px;font-weight:600;
  border:1px solid transparent;
}
.sectnav a i{font-size:10px}
.sectnav a:hover{color:var(--txt);background:var(--panel)}
.sectnav a.active{color:var(--accent);background:var(--panel);border-color:var(--line)}
.sectnav .cnt{background:var(--accent);color:#1a1a1a;border-radius:5px;padding:1px 6px;font-weight:800;font-size:10px}
@media(max-width:900px){.sectnav a span.cnt{display:inline}.sectnav a{padding:6px 8px}}

.controls{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-left:auto}
.ctl{
  background:var(--panel);border:1px solid var(--line);color:var(--txt);
  border-radius:4px;padding:7px 10px;font-size:13px;line-height:1;
  appearance:none;-webkit-appearance:none;cursor:pointer;
}
select.ctl{padding-right:26px;background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='10' height='6' viewBox='0 0 10 6'><path d='M0 0l5 6 5-6z' fill='%2393a0b8'/></svg>");background-repeat:no-repeat;background-position:right 9px center}
.ctl:focus{outline:2px solid var(--accent-2);outline-offset:1px}
button.ctl:active{transform:scale(.96)}
button.icon{width:36px;height:34px;display:inline-flex;align-items:center;justify-content:center;font-size:15px;padding:0}
button.primary{background:var(--accent);border-color:var(--accent);color:#1a1a1a;font-weight:700}

.search-wrap{position:relative}
#search{width:130px;transition:width .25s}
#search:focus{width:190px}
@media(max-width:480px){#search{width:96px}#search:focus{width:140px}}

/* ---------- Stage (canvas area) ---------- */
.stage{
  position:relative;flex:none;
  height:calc(100dvh - var(--bar-h) - 64px); /* 64px peek of next section */
  min-height:340px;
  background:#0b0e14 url('../img/bg.jpg') no-repeat center center;
  background-size:cover;
}
.stage::after{ /* soft fade into the page so the peek reads naturally */
  content:'';position:absolute;left:0;right:0;bottom:0;height:56px;
  background:linear-gradient(to bottom,transparent,var(--bg));pointer-events:none;
}
#canvas{position:absolute;inset:0;width:100%;height:100%;display:block;touch-action:manipulation}

/* legend overlay */
.legend{
  position:absolute;left:8px;bottom:8px;z-index:5;max-width:min(62vw,340px);
  background:rgba(11,14,20,.78);border:1px solid var(--line);border-radius:5px;
  backdrop-filter:blur(6px);overflow:hidden;
}
#legendToggle{
  display:flex;align-items:center;gap:7px;width:100%;
  background:none;border:0;color:var(--txt);font-size:11.5px;font-weight:600;
  padding:8px 10px;cursor:pointer;font-family:inherit;
}
#legendToggle .chev{margin-left:auto;font-size:10px;color:var(--muted);transition:transform .22s}
.legend.collapsed .chev{transform:rotate(-90deg)}
.lg-body{
  display:flex;flex-wrap:wrap;gap:4px 8px;padding:0 10px 9px;
  font-size:10.5px;color:var(--muted);
  max-height:220px;opacity:1;transition:max-height .25s ease,opacity .18s ease,padding .25s ease;
}
.legend.collapsed .lg-body{max-height:0;padding-top:0;padding-bottom:0;opacity:0;overflow:hidden}
.lg-note{flex-basis:100%;font-size:10px;color:var(--muted);font-style:italic}
.lg-body .key{display:inline-flex;align-items:center;gap:5px;white-space:nowrap}
.lg-body .dot{width:9px;height:9px;border-radius:50%;flex:none}


/* quiz hud */
.quizhud{
  position:absolute;top:10px;left:50%;transform:translateX(-50%);z-index:6;
  display:none;align-items:center;gap:12px;padding:9px 16px;border-radius:4px;
  background:rgba(20,25,38,.92);border:1px solid var(--accent);box-shadow:0 6px 24px rgba(0,0,0,.5);
  font-size:14px;white-space:nowrap;
}
.quizhud.on{display:flex}
.quizhud .target{font-weight:800;color:var(--accent);font-size:16px}
.quizhud .meta{color:var(--muted);font-size:12px;font-family:ui-monospace,monospace}

/* first-visit coach */
.coach{
  position:absolute;top:14px;left:50%;transform:translate(-50%,-6px);z-index:6;
  display:flex;align-items:center;gap:12px;max-width:min(88vw,420px);
  background:rgba(20,25,38,.94);border:1px solid var(--accent);border-radius:5px;
  padding:12px 16px;font-size:13.5px;line-height:1.5;color:var(--txt);
  box-shadow:0 8px 30px rgba(0,0,0,.5);opacity:0;pointer-events:none;
  transition:opacity .4s,transform .4s;
}
.coach.show{opacity:1;transform:translate(-50%,0)}
.coach.gone{opacity:0;transform:translate(-50%,-6px)}
.coach .bi-hand-index-thumb{font-size:22px;color:var(--accent);animation:tapnudge 1.6s ease-in-out infinite}
.coach small{color:var(--muted)}
@keyframes tapnudge{0%,100%{transform:translateY(0)}50%{transform:translateY(5px)}}
@media(prefers-reduced-motion:reduce){.coach .bi-hand-index-thumb{animation:none}}

/* toast */
.toast{
  position:fixed;bottom:18px;left:50%;transform:translateX(-50%);z-index:60;
  background:var(--panel-2);border:1px solid var(--line);color:var(--txt);
  padding:10px 16px;border-radius:5px;font-size:13.5px;max-width:88vw;text-align:center;
  opacity:0;pointer-events:none;transition:opacity .25s;
}
.toast.show{opacity:1}

/* speak button speaking-state (in modal head) */
#speakBtn{transition:border-color .15s}
#speakBtn.speaking{
  border-color:var(--accent);width:auto;padding:0 11px;gap:7px;
  display:inline-flex;align-items:center;justify-content:center;
}
#speakBtn .bi-stop-fill{color:var(--accent)}
.eq{display:inline-flex;align-items:flex-end;gap:2px;height:13px}
.eq i{width:3px;background:var(--accent);border-radius:1px;animation:eq .9s ease-in-out infinite}
.eq i:nth-child(2){animation-delay:.25s}
.eq i:nth-child(3){animation-delay:.5s}
@keyframes eq{0%,100%{height:4px}50%{height:13px}}
@media(prefers-reduced-motion:reduce){.eq i{height:8px;animation:none}}

/* tooltip (desktop hover) */
.tip{
  position:fixed;z-index:50;pointer-events:none;opacity:0;transition:opacity .12s;
  background:rgba(15,19,29,.95);border:1px solid var(--line);border-radius:4px;
  padding:8px 11px;font-size:12px;line-height:1.5;max-width:230px;
  box-shadow:0 8px 26px rgba(0,0,0,.5);
}
.tip.show{opacity:1}
.tip b{color:var(--accent)}
.tip .sub{color:var(--muted)}

/* ---------- Collection / table ---------- */
.section{max-width:1060px;margin:0 auto;width:100%;padding:18px 14px}
.section h2{font-size:15px;margin:0 0 4px;display:flex;align-items:center;gap:8px}
.section .hint{color:var(--muted);font-size:12px;margin:0 0 12px}
.count-pill{background:var(--accent);color:#1a1a1a;font-size:11px;font-weight:800;border-radius:20px;padding:2px 8px}

.tbl-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:var(--radius)}
table{width:100%;border-collapse:collapse;font-size:13px;background:var(--panel)}
th,td{text-align:left;padding:9px 12px;border-bottom:1px solid var(--line);white-space:nowrap}
th{color:var(--muted);font-size:11px;text-transform:uppercase;letter-spacing:.5px;background:var(--panel-2)}
tbody tr{cursor:pointer}
tbody tr:hover{background:var(--panel-2)}
tbody tr:last-child td{border-bottom:none}
td .sym{display:inline-block;min-width:30px;font-weight:700;color:var(--accent)}
.empty-row td{color:var(--muted);text-align:center;padding:22px;cursor:default}
@keyframes flashrow{0%{background:rgba(255,193,7,.35)}100%{background:transparent}}
tr.flash{animation:flashrow 1s ease-out}

/* ---------- Browse grid (SEO/crawlable) ---------- */
.browse{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:8px}
.browse a{
  display:flex;gap:9px;align-items:center;padding:9px 10px;border-radius:4px;
  background:var(--panel);border:1px solid var(--line);color:var(--txt);
  text-decoration:none;font-size:12.5px;
}
.browse a:hover{border-color:var(--accent-2);background:var(--panel-2)}
.browse .bsym{width:34px;height:34px;border-radius:4px;display:flex;align-items:center;justify-content:center;font-weight:800;font-size:13px;color:#fff;flex:none}
.browse .bnum{color:var(--muted);font-size:10.5px}
details.browse-details>summary{cursor:pointer;color:var(--muted);font-size:13px;padding:6px 0;list-style:none}
details.browse-details>summary::before{content:'\25B8  '}
details.browse-details[open]>summary::before{content:'\25BE  '}
details.browse-details[open]>summary{margin-bottom:12px}

/* ---------- Modal ---------- */
.modal-back{
  position:fixed;inset:0;z-index:80;background:rgba(4,6,10,.7);backdrop-filter:blur(4px);
  display:none;align-items:flex-end;justify-content:center;
}
@media(min-width:640px){.modal-back{align-items:center;padding:26px}}
.modal-back.open{display:flex}
.modal{
  background:var(--panel);border:1px solid var(--line);width:100%;max-width:640px;
  max-height:92dvh;display:flex;flex-direction:column;border-radius:8px 8px 0 0;
  animation:slideup .22s ease-out;
}
@media(min-width:640px){.modal{border-radius:4px;max-height:86vh}}
@keyframes slideup{from{transform:translateY(28px);opacity:.4}to{transform:none;opacity:1}}
.modal-head{
  display:flex;align-items:center;gap:14px;padding:16px 18px;border-bottom:1px solid var(--line);
}
.modal-head .msym{
  width:58px;height:58px;border-radius:5px;flex:none;display:flex;flex-direction:column;
  align-items:center;justify-content:center;color:#fff;font-weight:800;font-size:21px;line-height:1;
  box-shadow:inset 0 0 0 2px rgba(255,255,255,.22);
}
.modal-head .msym small{font-size:9.5px;font-weight:600;opacity:.85;margin-top:2px}
.modal-head h3{margin:0;font-size:19px}
.modal-head .mcat{color:var(--muted);font-size:12px;text-transform:capitalize}
.modal-head .spacer{margin-left:auto;display:flex;gap:8px}
.modal-body{overflow-y:auto;padding:16px 18px;-webkit-overflow-scrolling:touch}
.modal-body h4{font-size:11px;text-transform:uppercase;letter-spacing:.8px;color:var(--muted);margin:20px 0 8px}
.modal-body h4:first-child{margin-top:0}
.facts{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:8px}
.fact{background:var(--panel-2);border:1px solid var(--line);border-radius:4px;padding:8px 11px}
.fact .k{font-size:10px;color:var(--muted);text-transform:uppercase;letter-spacing:.4px}
.fact .v{font-size:13.5px;font-weight:600;margin-top:3px;word-break:break-word}
.fact .e{font-size:10.5px;color:var(--muted);margin-top:3px;font-style:italic}
.summary{font-size:13.5px;line-height:1.65;color:#c9d3e4}
.modal-body img.el-img{max-width:100%;border-radius:5px;display:block;margin:0 auto}
.img-cap{font-size:11px;color:var(--muted);text-align:center;margin-top:6px}
.modal-body model-viewer{width:100%;height:280px;background:var(--panel-2);border-radius:5px}
.outlinks{display:flex;gap:8px;flex-wrap:wrap}
.outlinks a{
  display:inline-block;padding:8px 13px;border-radius:4px;background:var(--panel-2);
  border:1px solid var(--line);color:var(--txt);text-decoration:none;font-size:12.5px;
}
.outlinks a:hover{border-color:var(--accent)}

/* ---------- Quiz leaderboard ---------- */
.lb-hero{text-align:center;padding:6px 0 14px}
.lb-big{font-size:52px;font-weight:800;line-height:1}
.lb-big small{font-size:20px;color:var(--muted);font-weight:600}
.lb-best{margin-top:8px;color:var(--accent);font-weight:700;font-size:14px}
.lb-best.muted{color:var(--muted);font-weight:600}
.lb{list-style:none;margin:0;padding:0;border:1px solid var(--line);border-radius:5px;overflow:hidden}
.lb li{display:flex;align-items:center;gap:12px;padding:8px 12px;font-size:13px;background:var(--panel-2)}
.lb li+li{border-top:1px solid var(--line)}
.lb li.me{outline:1px solid var(--accent);outline-offset:-1px}
.lb-rank{width:22px;height:22px;border-radius:50%;background:var(--line);display:inline-flex;align-items:center;justify-content:center;font-size:11px;font-weight:800;flex:none}
.lb-rank.gold{background:#d9b76e;color:#1a1a1a}
.lb-rank.silver{background:#b8c2d0;color:#1a1a1a}
.lb-rank.bronze{background:#c08d5a;color:#1a1a1a}
.lb-score{font-weight:700}
.lb-date{margin-left:auto;color:var(--muted);font-size:11.5px}
.lb-actions{display:flex;gap:8px;margin-top:16px;justify-content:center}

/* quiz level picker */
.lvl{
  display:flex;flex-direction:column;gap:3px;width:100%;text-align:left;
  background:var(--panel-2);border:1px solid var(--line);border-radius:5px;
  padding:13px 15px;margin-bottom:8px;color:var(--txt);cursor:pointer;font-family:inherit;
  transition:border-color .15s,transform .1s;
}
.lvl:hover{border-color:var(--accent)}
.lvl:active{transform:scale(.99)}
.lvl-name{font-size:15px;font-weight:800}
.lvl-desc{font-size:12px;color:var(--muted)}
.lvl-best{font-size:11px;color:var(--accent);font-weight:700}

/* ---------- Footer ---------- */
footer{border-top:1px solid var(--line);padding:22px 14px 34px;color:var(--muted);font-size:12px}
footer .inner{max-width:1060px;margin:0 auto;display:flex;flex-wrap:wrap;gap:16px;align-items:center;justify-content:space-between}
footer a{color:var(--accent-2)}

/* reduced motion */
@media(prefers-reduced-motion:reduce){
  *{animation:none!important;transition:none!important}
}

/* FAQ accordion */
details.faq{
  background:var(--panel);border:1px solid var(--line);border-radius:5px;
  margin-bottom:8px;overflow:hidden;transition:border-color .15s;
}
details.faq:hover{border-color:#3a4356}
details.faq[open]{border-color:var(--accent)}
details.faq>summary{
  cursor:pointer;list-style:none;display:flex;align-items:center;gap:10px;
  padding:13px 15px;font-size:13.5px;font-weight:600;user-select:none;
}
details.faq>summary::-webkit-details-marker{display:none}
details.faq>summary::before{
  content:'+';flex:none;width:20px;height:20px;border-radius:50%;
  background:var(--panel-2);border:1px solid var(--line);
  display:inline-flex;align-items:center;justify-content:center;
  font-size:13px;font-weight:700;color:var(--accent);transition:transform .2s;
}
details.faq[open]>summary::before{content:'\2212';transform:rotate(180deg)}
.faq-a{
  margin:0;padding:0 15px 14px 45px;font-size:13px;line-height:1.7;color:#c9d3e4;
}

/* ad slots: invisible until ads.js is configured */
.ad-slot{display:none}
.ad-slot.on{display:block;margin:18px auto;max-width:820px;padding:0 16px}
.ad-slot.on::before{content:'Advertisement';display:block;font-size:9px;letter-spacing:1px;text-transform:uppercase;color:var(--muted);margin-bottom:4px}