/* =============================================================
   Bead Buddies — guide, worksheet and tool pages.
   Standalone and small: these pages load no app CSS or JS unless
   they carry the live board (the online abacus page).
   ============================================================= */
:root{
  --cream:#FFF6E9; --cream-2:#FFEFD8; --card:#FFFFFF; --ink:#2B2140; --soft:#5E5478; --line:#EADFCB;
  --grape:#6C4DF6; --grape-d:#4C3BCF; --link:#5236E0; --mango:#F2B705; --mint:#1FA886;
  --r:18px; --r-sm:12px;
  --shadow:0 5px 0 rgba(43,33,64,.08), 0 14px 30px rgba(43,33,64,.09);
  --font: ui-rounded,"SF Pro Rounded","Nunito","Segoe UI Variable","Segoe UI",system-ui,-apple-system,"Helvetica Neue",Arial,sans-serif;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark){
  :root{ --cream:#17112F; --cream-2:#1E1740; --card:#221A45; --ink:#F2EEFF; --soft:#B6ABDB; --line:#35295F; --link:#B3A3FF;
         --shadow:0 5px 0 rgba(0,0,0,.35), 0 14px 30px rgba(0,0,0,.4); }
}
*,*::before,*::after{ box-sizing:border-box; }
html{ -webkit-text-size-adjust:100%; }
body{ margin:0; font-family:var(--font); font-size:17.5px; line-height:1.68; color:var(--ink); background:var(--cream); }
img,svg{ max-width:100%; }
a{ color:var(--link); text-underline-offset:3px; text-decoration-thickness:1.5px; }
a:hover{ text-decoration-thickness:2.5px; }
:focus-visible{ outline:3px solid var(--mango); outline-offset:3px; border-radius:6px; }
.wrap{ max-width:1080px; margin:0 auto; padding:0 clamp(16px,4vw,32px); }
.skip{ position:absolute; left:-999px; top:8px; background:var(--card); padding:8px 14px; border-radius:10px; z-index:10; }
.skip:focus{ left:12px; }

/* ---------- header ---------- */
.site-head{ position:sticky; top:0; z-index:5; background:color-mix(in srgb, var(--cream) 90%, transparent);
  backdrop-filter:blur(10px); -webkit-backdrop-filter:blur(10px); border-bottom:1px solid var(--line); }
.head-row{ display:flex; align-items:center; gap:12px; min-height:62px; }
.brand{ display:flex; align-items:center; gap:9px; font-weight:900; font-size:18px; color:var(--ink); text-decoration:none; flex:none; }
.head-nav{ flex:1; min-width:0; overflow-x:auto; scrollbar-width:none; }
.head-nav::-webkit-scrollbar{ display:none; }
.head-nav ul{ display:flex; gap:2px; list-style:none; margin:0; padding:0; }
.head-nav li{ margin:0; }
.head-nav a{ display:block; padding:8px 12px; border-radius:999px; color:var(--soft); font-weight:800; font-size:15px; text-decoration:none; white-space:nowrap; }
.head-nav a:hover,.head-nav a[aria-current]{ background:var(--card); color:var(--ink); }
.head-cta{ flex:none; padding:9px 16px; border-radius:999px; background:linear-gradient(160deg,var(--grape),var(--grape-d));
  color:#fff; font-weight:900; font-size:15px; text-decoration:none; box-shadow:0 4px 0 rgba(43,33,64,.16); }
@media (max-width:640px){ .brand span{ display:none; } .head-nav a{ padding:8px 8px; font-size:14px; } .head-cta{ padding:8px 12px; font-size:14px; } }
/* on a phone the logo already goes home, so the three section links get the whole row */
@media (max-width:480px){ .head-cta{ display:none; } }

/* ---------- breadcrumbs ---------- */
.crumbs ol{ display:flex; flex-wrap:wrap; gap:6px; list-style:none; padding:0; margin:20px 0 0; font-size:14px; color:var(--soft); }
.crumbs li{ margin:0; }
.crumbs li+li::before{ content:"›"; margin-right:6px; opacity:.6; }
.crumbs a{ color:var(--soft); }

/* ---------- article ---------- */
.guide,.sheet-page,.tool-page,.hub{ max-width:780px; margin:0 auto; padding-bottom:20px; }
.hub{ max-width:1000px; }
.guide-head{ margin:18px 0 26px; }
.kicker{ margin:0 0 6px; font-size:13px; font-weight:900; letter-spacing:.8px; text-transform:uppercase; color:var(--link); }
h1{ font-size:clamp(30px,6vw,46px); line-height:1.08; letter-spacing:-.5px; margin:0 0 12px; }
h2{ font-size:clamp(22px,4.4vw,28px); line-height:1.2; margin:44px 0 12px; }
h3{ font-size:19px; margin:26px 0 6px; }
.lede{ font-size:clamp(18px,3.4vw,21px); color:var(--soft); margin:0 0 12px; line-height:1.5; }
.meta{ font-size:14px; color:var(--soft); margin:0; }
p,li{ max-width:70ch; }
ul,ol{ padding-left:1.3em; }
li{ margin:6px 0; }
strong,b{ font-weight:800; }
section[id],div[id]{ scroll-margin-top:84px; }

.toc{ background:var(--card); border-radius:var(--r); box-shadow:var(--shadow); padding:16px 22px; margin:0 0 10px; }
.toc p{ margin:0 0 4px; font-weight:900; font-size:13px; text-transform:uppercase; letter-spacing:.7px; color:var(--soft); }
.toc ol{ margin:0; columns:2 230px; column-gap:28px; }
.toc li{ margin:3px 0; font-size:15.5px; break-inside:avoid; }

/* ---------- boards and worked examples ---------- */
figure{ margin:24px 0; }
figure.board{ text-align:center; }
figure.board svg,.walk svg{ width:100%; height:auto; display:block; margin:0 auto; }
figcaption{ font-size:15px; color:var(--soft); line-height:1.5; margin-top:10px; }
figure.board figcaption{ max-width:52ch; margin-inline:auto; }
.walk{ margin:26px 0; padding:18px; background:var(--card); border-radius:var(--r); box-shadow:var(--shadow); }
.walk-title{ margin:0 0 16px; font-size:16px; }
.walk-grid{ display:grid; gap:20px 18px; grid-template-columns:repeat(auto-fill,minmax(min(100%,200px),1fr)); align-items:start; }
.step{ margin:0; position:relative; }
.step-no{ position:absolute; top:-9px; left:-7px; z-index:1; width:30px; height:30px; border-radius:50%; display:grid; place-items:center;
  font-weight:900; font-size:15px; background:var(--grape); color:#fff; box-shadow:0 3px 0 rgba(43,33,64,.22); }
.step.final .step-no{ background:var(--mint); }
.step figcaption{ color:var(--ink); font-size:14.5px; }
.hand{ display:inline-block; margin-top:5px; padding:2px 10px; border-radius:999px; font-size:12.5px; font-weight:800;
  background:color-mix(in srgb,var(--mango) 28%, transparent); }
.quiz summary{ cursor:pointer; font-weight:800; color:var(--ink); }
.answer{ font-size:28px; font-weight:900; margin:6px 0 0; color:var(--link); }

/* ---------- tables ---------- */
.table-wrap{ overflow-x:auto; margin:22px 0; -webkit-overflow-scrolling:touch; }
table{ border-collapse:collapse; width:100%; background:var(--card); border-radius:var(--r-sm); overflow:hidden; box-shadow:var(--shadow); font-size:15.5px; }
caption{ caption-side:top; text-align:left; font-weight:900; padding:0 0 8px; }
th,td{ padding:9px 12px; border-bottom:1px solid var(--line); text-align:left; vertical-align:top; }
thead th{ background:var(--cream-2); font-size:12.5px; text-transform:uppercase; letter-spacing:.5px; }
.move-chart{ font-size:13.5px; }
.move-chart th,.move-chart td{ text-align:center; padding:7px 3px; min-width:36px; }
.move-chart td{ font-weight:900; }
.t-direct{ background:color-mix(in srgb,#39B7FF 20%, var(--card)); }
.t-heaven{ background:color-mix(in srgb,#FF6B6B 22%, var(--card)); }
.t-compound{ background:color-mix(in srgb,#FFB020 26%, var(--card)); }
.t-five{ background:color-mix(in srgb,#2FD3A5 28%, var(--card)); }
.t-ten{ background:color-mix(in srgb,#FF7BC0 28%, var(--card)); }
.legend{ display:flex; flex-wrap:wrap; gap:8px; list-style:none; padding:0; margin:10px 0 0; font-size:13.5px; }
.legend li{ margin:0; padding:4px 11px; border-radius:999px; }
.legend b{ margin-right:5px; }

/* ---------- call to action, questions, related ---------- */
.cta-box{ margin:44px 0 10px; padding:24px; border-radius:var(--r); text-align:center; color:#fff;
  background:linear-gradient(135deg,var(--grape),#D94F97 62%,#E08A12); box-shadow:var(--shadow); }
.cta-box p{ margin:0 auto 14px; font-weight:800; font-size:19px; }
.btn{ display:inline-block; padding:13px 22px; border-radius:999px; font-weight:900; font-size:16px; text-decoration:none;
  background:#fff; color:var(--grape-d); box-shadow:0 5px 0 rgba(0,0,0,.14); border:0; cursor:pointer; font-family:inherit; }
.btn:hover{ transform:translateY(-1px); }
.cta-box .also{ margin:16px 0 0; font-size:14.5px; font-weight:700; }
.cta-box .also a{ color:#fff; }
.faq .qa{ background:var(--card); border-radius:var(--r-sm); box-shadow:var(--shadow); padding:4px 20px 16px; margin:12px 0; }
.faq h3{ margin:14px 0 4px; font-size:17.5px; }
.faq p{ margin:0; }
.related{ max-width:780px; margin:16px auto 40px; }
.related h2{ margin-top:10px; }
.cards{ display:grid; gap:12px; grid-template-columns:repeat(auto-fill,minmax(min(100%,230px),1fr)); }
.card{ display:flex; flex-direction:column; gap:4px; padding:16px 18px; border-radius:var(--r); background:var(--card); box-shadow:var(--shadow);
  color:var(--ink); text-decoration:none; border-top:5px solid var(--grape); }
.card b{ font-size:16.5px; line-height:1.3; }
.card span{ font-size:14px; color:var(--soft); line-height:1.45; }
.card:hover b{ color:var(--link); }
.stages{ list-style:none; padding:0; display:grid; gap:10px; }
.stages li{ margin:0; max-width:none; }
.stages a{ display:flex; gap:12px; align-items:flex-start; padding:12px 16px; border-radius:var(--r-sm); background:var(--card); box-shadow:var(--shadow); color:var(--ink); text-decoration:none; }
.stages .st-emoji{ font-size:26px; line-height:1.25; }
.stages span span{ display:block; font-size:14.5px; color:var(--soft); line-height:1.45; }
.glossary div{ padding:12px 0; border-bottom:1px solid var(--line); }
.glossary dt{ font-weight:900; font-size:18px; }
.glossary dd{ margin:4px 0 0; }

/* ---------- hubs ---------- */
.hub-group{ margin:36px 0; }
.hub-group h2{ margin:0 0 12px; }

/* ---------- worksheets ---------- */
.sheet-tools{ display:flex; flex-wrap:wrap; gap:14px; align-items:center; margin:0 0 22px; }
.sheet-tools .btn{ background:linear-gradient(160deg,var(--grape),var(--grape-d)); color:#fff; }
.sheet{ list-style:none; counter-reset:q; padding:0; display:grid; gap:12px; grid-template-columns:repeat(auto-fill,minmax(150px,1fr)); }
.sheet li{ counter-increment:q; margin:0; padding:16px 14px 12px; background:var(--card); border-radius:var(--r-sm); box-shadow:var(--shadow);
  font-variant-numeric:tabular-nums; font-size:21px; font-weight:800; position:relative; max-width:none; }
.sheet li::before{ content:counter(q); position:absolute; top:5px; right:10px; font-size:12px; color:var(--soft); font-weight:700; }
.sheet .blank{ display:block; border-bottom:2px dashed var(--line); height:30px; margin-top:6px; }
.sheet-chain li{ text-align:right; line-height:1.35; }
.sheet-chain .col{ display:block; padding-right:4px; }
.answers{ margin:24px 0; background:var(--card); border-radius:var(--r-sm); box-shadow:var(--shadow); padding:14px 20px; }
.answers summary{ cursor:pointer; font-weight:900; }
.answer-list{ columns:4 110px; font-variant-numeric:tabular-nums; }
.answer-list li{ margin:3px 0; }
.print-only{ display:none; }
.level-nav{ display:flex; justify-content:space-between; gap:12px; margin:32px 0; flex-wrap:wrap; font-weight:800; }

/* ---------- online abacus ---------- */
.tool{ background:var(--card); border-radius:var(--r); box-shadow:var(--shadow); padding:clamp(14px,3vw,24px); margin:10px 0 26px; }
.tool-controls{ display:flex; flex-wrap:wrap; gap:10px; align-items:center; justify-content:center; margin-top:16px; }
.tool-controls form{ display:flex; gap:8px; align-items:center; flex-wrap:wrap; justify-content:center; }
.tool-controls label{ font-weight:800; font-size:14px; display:flex; align-items:center; gap:6px; }
.tool-controls select,.tool-controls input{ font:inherit; font-size:16px; padding:8px 10px; border-radius:10px; border:2px solid var(--line); background:var(--cream-2); color:var(--ink); }
.tool-controls input{ width:9em; }
.tool-controls .btn{ background:linear-gradient(160deg,var(--grape),var(--grape-d)); color:#fff; padding:10px 18px; font-size:15px; }
.tool-controls .btn.ghost{ background:var(--cream-2); color:var(--ink); }
.readout{ text-align:center; margin:6px 0 0; }
.readout span{ display:block; font-size:12.5px; font-weight:800; text-transform:uppercase; letter-spacing:.8px; color:var(--soft); }
.readout output{ font-size:clamp(36px,9vw,54px); font-weight:900; color:var(--link); font-variant-numeric:tabular-nums; line-height:1.1; }

/* ---------- footer ---------- */
.site-foot{ margin-top:50px; padding:36px 0 44px; background:var(--card); border-top:1px solid var(--line); font-size:15px; }
.foot-grid{ display:grid; gap:24px; grid-template-columns:repeat(auto-fill,minmax(200px,1fr)); }
.site-foot h2{ font-size:13px; text-transform:uppercase; letter-spacing:.8px; margin:0 0 8px; color:var(--soft); }
.site-foot ul{ list-style:none; padding:0; margin:0; }
.site-foot li{ margin:5px 0; }
.site-foot a{ color:var(--ink); text-decoration:none; }
.site-foot a:hover{ color:var(--link); text-decoration:underline; }
.foot-note{ display:flex; align-items:center; gap:8px; margin:28px 0 0; color:var(--soft); font-size:14px; max-width:none; }

@media print{
  .site-head,.site-foot,.crumbs,.no-print,.answers,.related,.cta-box,.level-nav,.skip,.sheet-help{ display:none !important; }
  .print-only{ display:block; margin:0 0 16px; font-size:14pt; }
  body{ background:#fff; color:#000; font-size:13pt; }
  .sheet{ grid-template-columns:repeat(4,1fr); gap:8px; }
  .sheet li{ box-shadow:none; border:1px solid #888; break-inside:avoid; }
  .guide-head{ margin:0 0 12px; }
  h1{ font-size:22pt; }
  .lede{ font-size:12pt; color:#333; }
}
@media (prefers-reduced-motion: reduce){ *{ transition:none !important; animation:none !important; } }