/* ============================================================
   Guess the Correlation — tool-wide styles
   Shared by index / tutorial / learn. Page-specific rules stay in
   each page's own <style> block.
   shared/brand.css owns the LLL-wide palette; this owns the bits
   that are specific to this tool but common to all of its pages.
   ============================================================ */

/* ---------- the correlation scale ----------
   Single source of truth for blue -> grey -> orange. Drives the
   strength guide, the slider rail, and every dot on every page.
   corr.js reads these back out of CSS rather than hardcoding them. */
:root {
  --r-neg: #4a7fb0;
  --r-mid: #c9c9c4;
  --r-pos: #e0843c;
  --r-scale: linear-gradient(90deg, var(--r-neg), var(--r-mid) 50%, var(--r-pos));
  --tier-1: #0f6e56;
  --tier-2: #3f7d43;
  --tier-3: #a5762a;
  --tier-4: #a04a3c;
  --grid: rgba(0,0,0,.06);
}
:root[data-theme="dark"] {
  --r-neg: #6ea3d2;
  --r-mid: #9d9d98;
  --r-pos: #eb9a5c;
  --tier-1: #57c9a6;
  --tier-2: #77c07c;
  --tier-3: #d8ac5c;
  --tier-4: #e08b7c;
  --grid: rgba(255,255,255,.07);
}

body { justify-content: flex-start; }

/* ---------- navbar ---------- */
.nav-lang { display: flex; align-items: center; gap: 8px; }
.lll-nav { position: sticky; top: 0; z-index: 40; }

/* ---------- page shell ---------- */
.wrap {
  width: 100%; max-width: 560px; margin: 0 auto;
  padding: 20px 20px 48px;
  display: flex; flex-direction: column; gap: 16px;
}
.wrap.wide { max-width: 640px; }

.pagehead h1 { font-size: 24px; letter-spacing: -0.02em; margin: 0 0 6px; }
.pagehead p { font-size: 14px; line-height: 1.65; color: var(--muted); margin: 0; }

/* ---------- sections ---------- */
.section { margin-top: 26px; }
.section h2 { font-size: 16px; font-weight: 700; margin: 0 0 12px; }
.section h3 { font-size: 14px; font-weight: 700; margin: 0 0 6px; }
.prose { background: var(--accent-tint); border-radius: 14px; padding: 16px; font-size: 14px; line-height: 1.65; }
.callout { background: var(--surface); border: 1px solid var(--border); border-left: 4px solid var(--r-pos);
  border-radius: 12px; padding: 14px 16px; }
.callout h3 { margin: 0 0 6px; font-size: 14px; }
.callout p { margin: 0; font-size: 14px; line-height: 1.6; color: var(--muted); }
.tipbox { margin-top: 12px; background: var(--surface); border: 1px solid var(--border);
  border-left: 4px solid var(--r-pos); border-radius: 12px; padding: 12px 14px;
  font-size: 13px; line-height: 1.6; color: var(--muted); }

/* ---------- plots ---------- */
.plotcard { background: var(--surface); border: 1px solid var(--border); border-radius: 14px; padding: 14px; }
.plot { width: 100%; height: auto; display: block; --dotc: var(--r-mid); }
.axis { stroke: var(--border); stroke-width: 1.2; }
.grid { stroke: var(--grid); stroke-width: 1; }
.tick { stroke: var(--border); stroke-width: 1; }
.axlabel { fill: var(--muted); font-family: var(--sans); font-size: 9px; }

/* Dots read their colour from --dotc so a single property update recolours
   the whole cloud, and `transition: fill` animates it for free. */
.dot { fill: var(--dotc); opacity: .8; transition: fill .45s ease;
  transform-box: fill-box; transform-origin: center;
  animation: dotIn .34s cubic-bezier(.2,1.3,.4,1) backwards; }
:root[data-theme="dark"] .dot { opacity: .88; }
@keyframes dotIn { from { opacity: 0; transform: scale(.25); } }

.fit { stroke: var(--ink); stroke-width: 2; stroke-linecap: round; opacity: 0; }
.fit.show { opacity: .85; animation: drawIn .55s ease-out forwards; }
@keyframes drawIn { from { stroke-dashoffset: var(--len); } to { stroke-dashoffset: 0; } }

/* ---------- guess slider ---------- */
.guessbox { display:flex; flex-direction:column; gap:8px; }
.guessrow { display:flex; align-items:center; gap:8px; }

/* The value readout is an input: typing and dragging are both always live,
   with no mode to switch between them. */
input.guessval { flex:none; width:78px; font-family:var(--mono); font-size:21px; font-weight:700;
  text-align:center; font-variant-numeric:tabular-nums; color:var(--ink);
  background:var(--bg); border:1px solid var(--border); border-radius:9px; padding:8px 2px;
  transition:border-color .15s ease, box-shadow .15s ease; }
input.guessval:focus { outline:none; border-color:var(--accent); box-shadow:0 0 0 3px var(--accent-tint); }
input.guessval:disabled { opacity:.75; }

/* iOS shows no minus key on a decimal keypad, so on touch this button is the
   only way to enter a negative r at all. */
.signbtn { flex:none; width:36px; height:41px; font-family:var(--mono); font-size:16px; font-weight:700;
  color:var(--ink); background:var(--surface); border:1px solid var(--border); border-radius:9px;
  cursor:pointer; transition:border-color .15s ease, background .15s ease; }
.signbtn:hover { border-color:var(--muted); }
.signbtn:active { background:var(--bg); }
.signbtn:focus-visible { outline:2px solid var(--accent); outline-offset:1px; }
.signbtn:disabled { opacity:.4; cursor:default; }

.enterhint { font-size:11.5px; color:var(--muted); text-align:center; margin:2px 0 0; }
/* Enter-to-check is a keyboard affordance; don't promise it to touch users. */
@media (hover: none) { .enterhint { display:none; } }

.sliderwrap { position:relative; flex:1; height:46px; }
.rail { position:absolute; left:0; right:0; top:29px; height:8px; border-radius:999px;
  background:var(--r-scale); opacity:.4; transition:opacity .3s ease; }
.sliderwrap.revealed .rail { opacity:1; }
.band { position:absolute; top:27px; height:12px; border-radius:3px; display:none;
  background:currentColor; opacity:.32; transform-origin:left center; }
.band.on { display:block; animation:bandIn .45s cubic-bezier(.2,1,.4,1); }
@keyframes bandIn { from { transform:scaleX(.02); } }
.truth { position:absolute; top:21px; width:3px; height:24px; border-radius:2px;
  background:var(--ink); display:none; }
.truth.on { display:block; animation:popIn .3s cubic-bezier(.2,1.3,.4,1); }
.truth .tval { position:absolute; bottom:29px; left:50%; transform:translateX(-50%);
  font-family:var(--mono); font-size:11px; font-weight:700; white-space:nowrap;
  background:var(--ink); color:var(--on-accent); padding:2px 6px; border-radius:5px; }
.truth .tval::after { content:""; position:absolute; top:100%; left:50%; margin-left:-3px;
  border:3px solid transparent; border-top-color:var(--ink); }

input[type=range] { position:absolute; inset:0; width:100%; margin:0; background:transparent;
  -webkit-appearance:none; appearance:none; cursor:pointer; }
input[type=range]:focus { outline:none; }
input[type=range]::-webkit-slider-runnable-track { height:8px; background:transparent; margin-top:29px; }
input[type=range]::-webkit-slider-thumb { -webkit-appearance:none; width:20px; height:20px;
  border-radius:50%; background:var(--surface); border:2.5px solid var(--ink);
  margin-top:-6px; box-shadow:0 1px 5px rgba(0,0,0,.22); transition:transform .12s ease; }
input[type=range]:active::-webkit-slider-thumb { transform:scale(1.15); }
input[type=range]:focus-visible::-webkit-slider-thumb { box-shadow:0 0 0 4px var(--accent-tint); }
input[type=range]::-moz-range-track { height:8px; background:transparent; }
input[type=range]::-moz-range-thumb { width:20px; height:20px; border-radius:50%;
  background:var(--surface); border:2.5px solid var(--ink); box-shadow:0 1px 5px rgba(0,0,0,.22); }
input[type=range]:disabled { cursor:default; }

.scaleends { display:flex; justify-content:space-between; font-size:11px; color:var(--muted);
  font-family:var(--mono); }
.controls { display:flex; gap:10px; }

/* ---------- result ---------- */
.result { border-radius:14px; padding:16px; border:1px solid var(--border);
  border-left:4px solid var(--tierc, var(--accent));
  background:var(--accent-tint);
  animation:resultIn .3s ease-out; }
@supports (background: color-mix(in srgb, red 9%, blue)) {
  .result { background: color-mix(in srgb, var(--tierc, var(--accent)) 10%, var(--surface)); }
}
@keyframes resultIn { from { opacity:0; transform:translateY(-6px); } }
.verdict { font-size:16px; font-weight:700; color:var(--tierc, var(--ink));
  display:flex; align-items:baseline; gap:8px; }
.verdict .pts { font-family:var(--mono); font-size:14px; margin-left:auto; }
.rline { margin-top:10px; font-size:15px; }
.rline .num { font-family:var(--mono); font-weight:700; }
.rmiss { margin-top:4px; font-size:13px; color:var(--muted); font-family:var(--mono); }
.rdesc { margin-top:8px; font-size:14px; line-height:1.6; color:var(--muted); }
.trap { margin-top:12px; background:var(--surface); border:1px solid var(--border);
  border-left:4px solid var(--r-pos); border-radius:10px; padding:11px 13px; }
.trap .tt { font-size:11px; font-weight:800; letter-spacing:.05em; text-transform:uppercase;
  color:var(--r-pos); margin-bottom:5px; }
.trap p { margin:0 0 6px; font-size:13px; line-height:1.6; color:var(--ink); }
.trap .tlink { margin:0; font-size:13px; }
.trap .tlink a { color:var(--muted); }
/* Shown on a trap round only when the two coefficients actually disagree,
   so it stays a revelation rather than background noise. */
.trapcmp { display:flex; gap:8px; margin:10px 0; }
.trapcmp .tc { flex:1; background:var(--bg); border:1px solid var(--border);
  border-radius:8px; padding:7px 9px; text-align:center; }
.trapcmp .tc .k { font-size:10px; color:var(--muted); }
.trapcmp .tc .v { font-family:var(--mono); font-size:15px; font-weight:700; margin-top:1px;
  font-variant-numeric:tabular-nums; }
.trapcmp .tc.lo .v { color:var(--tier-4); }
.trapcmp .tc.hi .v { color:var(--tier-1); }


/* ---------- example plot grid ---------- */
.exgrid { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 10px; margin-top: 12px; }
@media (max-width: 460px) { .exgrid { grid-template-columns: 1fr; } }
.ex { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 10px; }
.ex svg { width: 100%; height: auto; display: block; }
.ex .cap { font-size: 11px; color: var(--muted); text-align: center; margin-top: 6px; line-height: 1.4; }
.ex .rv { font-family: var(--mono); font-size: 12px; font-weight: 700; text-align: center; margin-top: 4px; }

/* ---------- strength guide ---------- */
.guidebar { height: 14px; border-radius: 999px; background: var(--r-scale); }
.guidelabels { display: flex; justify-content: space-between; font-size: 11px; color: var(--muted); margin-top: 6px; }

/* ---------- buttons ---------- */
.btn.secondary { background: transparent; color: var(--ink); border: 1px solid var(--border); }
.btn.secondary:hover { background: var(--bg); filter: none; }
.btn:disabled { opacity: .4; cursor: default; filter: none; }
.linkbtn { background: none; border: none; padding: 0; font-family: var(--sans);
  font-size: 12px; color: var(--muted); text-decoration: underline; cursor: pointer; }
.linkbtn:hover { color: var(--ink); }

/* ---------- cross-page call to action ---------- */
.cta { display: flex; align-items: center; gap: 12px; background: var(--accent-tint);
  border-radius: 14px; padding: 14px 16px; text-decoration: none; color: var(--ink); }
.cta:hover { filter: brightness(.97); }
.cta .ct { flex: 1; }
.cta .ct b { font-size: 14px; display: block; }
.cta .ct span { font-size: 13px; color: var(--muted); }
.cta .arw { font-size: 18px; color: var(--muted); }

/* ---------- footer ---------- */
.foot { margin-top: 34px; padding-top: 20px; border-top: 1px solid var(--border); text-align: center; }
.foot p { font-size: 13px; color: var(--muted); margin: 0 0 12px; }
.foot a.gh { display: inline-flex; align-items: center; gap: 7px; font-size: 13px; font-weight: 600;
  color: var(--ink); text-decoration: none; border: 1px solid var(--border); border-radius: 9px;
  padding: 8px 14px; background: var(--surface); }
.foot a.gh:hover { border-color: var(--accent); }

/* ---------- toast ---------- */
.toast { position: fixed; left: 50%; bottom: 28px; transform: translateX(-50%);
  background: var(--ink); color: var(--on-accent); font-size: 13px; font-weight: 600;
  padding: 10px 18px; border-radius: 999px; z-index: 70; box-shadow: 0 8px 24px rgba(0,0,0,.25);
  animation: toastIn .25s ease-out; }
@keyframes toastIn { from { opacity: 0; transform: translateX(-50%) translateY(8px); } }

@media (prefers-reduced-motion: reduce) {
  .dot { animation: none !important; }
  .fit.show { animation: none !important; stroke-dashoffset: 0 !important; }
  .toast { animation: none !important; }
}