/* ==========================================================================
   Inter, served from assets/fonts/ (see assets/README.md). One variable file
   per script covers the three weights in use: 400, 500 and 600. A browser
   only downloads the files whose characters appear on the page.
   ========================================================================== */
@font-face{font-family:'Inter';font-style:normal;font-weight:400 600;font-display:swap;src:url(fonts/inter-greek.woff2) format('woff2');unicode-range:U+0370-0377,U+037A-037F,U+0384-038A,U+038C,U+038E-03A1,U+03A3-03FF}
@font-face{font-family:'Inter';font-style:normal;font-weight:400 600;font-display:swap;src:url(fonts/inter-latin-ext.woff2) format('woff2');unicode-range:U+0100-02BA,U+02BD-02C5,U+02C7-02CC,U+02CE-02D7,U+02DD-02FF,U+0304,U+0308,U+0329,U+1D00-1DBF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C4,U+2113,U+2C60-2C7F,U+A720-A7FF}
@font-face{font-family:'Inter';font-style:normal;font-weight:400 600;font-display:swap;src:url(fonts/inter-latin.woff2) format('woff2');unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}

/* ==========================================================================
   Leandro Junes — shared site styles
   Light tokens live on :root; dark tokens override under [data-theme="dark"].
   Every page includes this file, so a token or component changed here
   changes everywhere.
   ========================================================================== */

:root{
  --bg:#f6f7f6;
  --surface:#ffffff;
  --surface-2:#eff2f1;
  --border:#dde3e1;
  --border-strong:#c4ceca;
  --text:#16201e;
  --text-soft:#4d5c58;
  --text-faint:#7c8b87;
  --accent:#0c6a5d;
  --accent-hover:#08544a;
  --accent-wash:#e6f1ef;
  --accent-on:#ffffff;
  --warn:#a3341f;
  --warn-wash:#fbeeea;
  --shadow:0 1px 2px rgba(10,20,18,.05), 0 8px 24px rgba(10,20,18,.06);

  --sans:'Inter',system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --mono:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,monospace;
}

:root[data-theme="dark"]{
  --bg:#0f1416;
  --surface:#161d1f;
  --surface-2:#1c2528;
  --border:#283438;
  --border-strong:#3a494e;
  --text:#e7eeec;
  --text-soft:#a9b8b4;
  --text-faint:#7f908c;
  --accent:#34c9b0;
  --accent-hover:#54dcc4;
  --accent-wash:#14302c;
  --accent-on:#07201c;
  --warn:#ef8163;
  --warn-wash:#33201b;
  --shadow:0 1px 2px rgba(0,0,0,.4), 0 10px 28px rgba(0,0,0,.35);
}

*{box-sizing:border-box;margin:0;padding:0}

body{
  background:var(--bg);
  color:var(--text);
  font-family:var(--sans);
  font-size:16.5px;
  line-height:1.62;
  -webkit-font-smoothing:antialiased;
}
a{color:var(--accent)}
input,table,.value,.stat dd{font-variant-numeric:tabular-nums}

.wrap{max-width:1120px;margin:0 auto;padding:0 clamp(1rem,3.5vw,2rem)}

button:focus-visible,a:focus-visible,input:focus-visible{
  outline:2px solid var(--accent);outline-offset:2px;
}

/* ==========================================================================
   Theme toggle (button markup is shared in partials.js; this styles it)
   ========================================================================== */
.theme-btn{
  display:flex;align-items:center;gap:.4rem;
  background:var(--surface);color:var(--text-soft);
  border:1px solid var(--border);border-radius:7px;
  padding:.35rem .6rem;font:inherit;font-size:.85rem;cursor:pointer;
}
.theme-btn:hover{color:var(--text);border-color:var(--border-strong)}
.theme-btn svg{width:16px;height:16px}
.theme-btn .lbl{display:none}
@media (min-width:640px){.theme-btn .lbl{display:inline}}
:root[data-theme="dark"] .icon-sun{display:block}
:root[data-theme="dark"] .icon-moon{display:none}
:root:not([data-theme="dark"]) .icon-sun{display:none}
:root:not([data-theme="dark"]) .icon-moon{display:block}

/* ==========================================================================
   Top bar (used on every page except the landing page, which has its own
   centered hero instead of a bar)
   ========================================================================== */
.topbar{
  position:sticky;top:0;z-index:20;
  background:color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter:blur(8px);
  border-bottom:1px solid var(--border);
}
.topbar-inner{display:flex;align-items:center;gap:1rem;padding:.6rem 0}
.mark{display:flex;align-items:center;gap:.55rem;text-decoration:none;color:var(--text);margin-right:auto;font-weight:600}
.mark svg{width:26px;height:auto;color:var(--accent)}
.topnav{display:flex;gap:.15rem;flex-wrap:wrap}
.topnav a{text-decoration:none;color:var(--text-soft);font-size:.93rem;padding:.38rem .6rem;border-radius:6px}
.topnav a:hover{color:var(--text);background:var(--surface-2)}
.topnav a[aria-current=page]{color:var(--accent);background:var(--accent-wash)}

/* Narrow screens: the name and the theme button share the first row, and the navigation takes a row of its own that
   scrolls sideways instead of wrapping. Its right edge fades out, to show that there is more; theme.js scrolls the
   current page into view. */
@media (max-width:760px){
  .topbar-inner{flex-wrap:wrap;gap:.3rem 1rem;padding:.5rem clamp(1rem,3.5vw,2rem) .4rem}
  .mark{white-space:nowrap}
  .topnav{
    order:3;flex:0 0 100%;flex-wrap:nowrap;overflow-x:auto;
    margin:0 -.6rem;padding-right:2rem;
    scrollbar-width:none;
    -webkit-mask-image:linear-gradient(to right,#000 calc(100% - 2rem),transparent);
            mask-image:linear-gradient(to right,#000 calc(100% - 2rem),transparent);
  }
  .topnav::-webkit-scrollbar{display:none}
  .topnav a{flex:none;white-space:nowrap}
}

/* ==========================================================================
   Masthead — page title block under the top bar
   ========================================================================== */
.masthead{padding:clamp(1.7rem,4vw,2.6rem) 0 .6rem}
.crumbs{font-size:.87rem;color:var(--text-faint);margin-bottom:.45rem}
.crumbs a{color:var(--text-soft);text-decoration:none}
.crumbs a:hover{color:var(--accent)}
.masthead h1{font-size:clamp(1.85rem,4vw,2.6rem);font-weight:600;letter-spacing:-.02em;line-height:1.12}
.lede{color:var(--text-soft);max-width:66ch;margin-top:.45rem}
.kbd{font-family:var(--mono);font-size:.9em;background:var(--surface-2);border:1px solid var(--border);border-radius:5px;padding:.05rem .35rem}

/* ==========================================================================
   Card — the basic content container used across tool pages
   ========================================================================== */
.card{background:var(--surface);border:1px solid var(--border);border-radius:12px;box-shadow:var(--shadow)}
.card + .card{margin-top:1.4rem}
.card-head{display:flex;align-items:center;gap:.6rem;padding:.85rem 1.15rem;border-bottom:1px solid var(--border)}
.card-head svg{width:20px;height:auto;color:var(--accent);flex:none}
.card-head h2{font-size:1rem;font-weight:600}
.card-head .meta{margin-left:auto;font-family:var(--mono);font-size:.78rem;color:var(--text-faint)}
.card-body{padding:1.15rem}

/* ==========================================================================
   Forms
   ========================================================================== */
.fields{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:1rem}
label{display:block;font-size:.86rem;font-weight:500;color:var(--text-soft);margin-bottom:.3rem}
label b{font-family:var(--mono);color:var(--accent)}

/* A repeated group of .fields rows (used by the Chinese remainder page for
   its 5 fixed a/n congruence-pair rows), each separated by a thin divider
   instead of another nested card. */
.crt-pair{
  padding-top:1rem;border-top:1px solid var(--border);
  opacity:1;transform:translateY(0);
  transition:opacity .18s ease,transform .18s ease;
}
.crt-pair:first-child{padding-top:0;border-top:none}
.crt-pair.crt-entering{opacity:0;transform:translateY(-6px)}
.crt-pair-label{display:flex;align-items:baseline;justify-content:space-between;gap:.5rem;margin-bottom:.5rem}
.crt-pair-title{font-size:.86rem;font-weight:500;color:var(--text-soft)}
.crt-tag{margin-left:.4rem;font-size:.72rem;letter-spacing:.06em;text-transform:uppercase;color:var(--text-faint);font-weight:500}
.card-body > .notes:first-child{margin-top:0;margin-bottom:1rem}

.crt-remove{
  background:transparent;border:none;border-radius:5px;
  color:var(--text-faint);font:inherit;font-size:.78rem;font-weight:500;
  cursor:pointer;padding:.15rem .4rem;white-space:nowrap;
  transition:color .18s ease,background-color .18s ease;
}
.crt-remove:hover{color:var(--warn);background:var(--warn-wash)}

.btn-add{
  display:inline-flex;align-items:center;
  background:transparent;border:none;border-radius:7px;
  color:var(--accent);font:inherit;font-size:.95rem;font-weight:500;
  padding:.45rem .6rem;margin:1rem 0 0 -.6rem;
  cursor:pointer;
  transition:color .18s ease,background-color .18s ease;
}
.btn-add:hover{color:var(--accent-hover);background:var(--accent-wash)}
.btn-add[hidden]{display:none}
input[type=text]{
  width:100%;font-family:var(--mono);font-size:1rem;padding:.6rem .7rem;
  color:var(--text);background:var(--bg);
  border:1px solid var(--border-strong);border-radius:8px;
  transition:border-color .15s ease,box-shadow .15s ease;
}
input[type=text]:focus{
  outline:none;border-color:var(--accent);
  box-shadow:0 0 0 3px color-mix(in srgb, var(--accent) 22%, transparent);
}
input[aria-invalid=true]{border-color:var(--warn);background:var(--warn-wash)}
.hint{font-size:.79rem;color:var(--text-faint);margin-top:.28rem;min-height:1.1em}
.hint.error{color:var(--warn)}

.actions{display:flex;flex-wrap:wrap;gap:.55rem;align-items:center;margin-top:1.1rem;padding-top:1rem;border-top:1px solid var(--border)}
button{font:inherit;cursor:pointer;border-radius:8px}
.btn-primary{background:var(--accent);color:var(--accent-on);border:1px solid transparent;padding:.55rem 1.2rem;font-weight:600}
.btn-primary:hover{background:var(--accent-hover)}
.btn-ghost{background:transparent;color:var(--text-soft);border:1px solid var(--border-strong);padding:.55rem .9rem}
.btn-ghost:hover{color:var(--text)}
.presets{margin-left:auto;display:flex;flex-wrap:wrap;gap:.4rem;align-items:center;font-size:.82rem;color:var(--text-faint)}
.presets button{background:var(--accent-wash);border:1px solid transparent;color:var(--accent);padding:.3rem .55rem;font-family:var(--mono);font-size:.8rem}
.presets button:hover{border-color:var(--accent)}

/* ==========================================================================
   Result / readout
   ========================================================================== */
.result{display:none}
.result.show{display:block}
.factor-continue-actions{display:flex;flex-wrap:wrap;gap:.55rem;margin-bottom:1rem}
.factor-continue-actions[hidden]{display:none}
.readout{display:flex;gap:1rem;align-items:flex-start;flex-wrap:wrap;background:var(--surface-2);border-radius:10px;padding:.95rem 1.05rem}
.readout > div{min-width:0}
.readout .expr{font-family:var(--mono);font-size:.86rem;color:var(--text-faint);word-break:break-all}
.value{font-family:var(--mono);font-size:clamp(1.7rem,4vw,2.3rem);font-weight:600;color:var(--accent);word-break:break-all;line-height:1.15}
.identity{font-family:var(--mono);font-size:.92rem;color:var(--text-soft);margin-top:.4rem}
.copy{margin-left:auto;background:var(--surface);border:1px solid var(--border-strong);color:var(--text-soft);padding:.35rem .7rem;font-size:.84rem}
.copy:hover{color:var(--accent);border-color:var(--accent)}

.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(122px,1fr));gap:.6rem;margin-top:1rem}
.stat{background:var(--bg);border:1px solid var(--border);border-radius:9px;padding:.55rem .7rem}
.stat dt{font-size:.72rem;letter-spacing:.07em;text-transform:uppercase;color:var(--text-faint)}
.stat dd{font-family:var(--mono);font-size:1rem;margin-top:.1rem;word-break:break-all}

/* ==========================================================================
   Bit row — a wrapping strip of .bit chips (binary digits, or an S/M
   operation sequence), used outside of the step table
   ========================================================================== */
.bit-row{display:flex;flex-wrap:wrap;gap:.35rem;margin-top:.5rem}
.seq-label{margin-top:1.1rem}
.num-wrap{overflow-wrap:anywhere}
.mono-cell{font-family:var(--mono)}

/* ==========================================================================
   Tables
   ========================================================================== */
.table-wrap{overflow-x:auto}
table{border-collapse:collapse;width:100%;font-size:.93rem}
th,td{padding:.45rem .7rem;border-bottom:1px solid var(--border);text-align:left}
thead th{font-size:.73rem;letter-spacing:.08em;text-transform:uppercase;color:var(--text-faint);font-weight:600;white-space:nowrap}
td.num,th.num{text-align:right;font-family:var(--mono)}
td.op{font-family:var(--mono);color:var(--text-soft);white-space:nowrap}
tbody tr:hover{background:var(--surface-2)}
.bit{font-family:var(--mono);font-weight:600;display:inline-block;min-width:1.5em;text-align:center;border-radius:5px;padding:0 .3rem}
.bit-1{background:var(--accent-wash);color:var(--accent)}
.bit-0{background:var(--surface-2);color:var(--text-faint)}
.notes{margin-top:.9rem;font-size:.9rem;color:var(--text-soft)}
.notes code{font-family:var(--mono);background:var(--surface-2);border-radius:5px;padding:.05rem .3rem}

/* ==========================================================================
   Tool page layout: content + sidebar
   ========================================================================== */
.layout{display:grid;grid-template-columns:minmax(0,1fr) 262px;gap:1.8rem;align-items:start;padding:1.2rem 0 4rem}
@media (max-width:900px){.layout{grid-template-columns:minmax(0,1fr)}}

.side h3{font-size:.75rem;letter-spacing:.12em;text-transform:uppercase;color:var(--text-faint);margin-bottom:.5rem}
.side + .side{margin-top:1.5rem}
.side ul{list-style:none;background:var(--surface);border:1px solid var(--border);border-radius:11px;overflow:hidden}
.side li + li{border-top:1px solid var(--border)}
.side a{display:flex;gap:.6rem;align-items:center;padding:.55rem .75rem;text-decoration:none;color:var(--text);font-size:.93rem}
.side svg{width:18px;height:auto;color:var(--accent);flex:none}
.side a:hover{background:var(--surface-2)}
.side a[aria-current=page]{background:var(--accent-wash);color:var(--accent);font-weight:500}
.note{background:var(--accent-wash);border:1px solid color-mix(in srgb, var(--accent) 35%, transparent);border-radius:11px;padding:.8rem .9rem;font-size:.89rem;color:var(--text)}
.before-factor-note{margin-bottom:1rem}
.note b{display:block;font-size:.74rem;letter-spacing:.09em;text-transform:uppercase;color:var(--accent);margin-bottom:.25rem}

/* ==========================================================================
   Section tiles — a grid of link cards (used by the calculators listing page,
   and anywhere else a set of items needs an icon + title + description)
   ========================================================================== */
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:1rem}
.tile{
  display:block;text-decoration:none;color:inherit;background:var(--surface);
  border:1px solid var(--border);border-radius:12px;padding:1.1rem;box-shadow:var(--shadow);
  transition:border-color .15s ease,transform .15s ease;
}
.tile:hover{border-color:var(--accent);transform:translateY(-2px)}
.tile svg{width:25px;height:auto;color:var(--accent);margin-bottom:.6rem}
.tile h3{font-size:1rem;font-weight:600}
.tile p{color:var(--text-soft);font-size:.9rem;margin-top:.25rem}

/* ==========================================================================
   Listing page — a single-column content area (no sidebar), grouped into
   labeled topic sections, each holding either a .grid of .tile cards or a
   .calc-list of rows
   ========================================================================== */
.listing{padding:2.2rem 0 4rem}
.topic + .topic{margin-top:2rem}
.topic h2{font-size:.75rem;letter-spacing:.12em;text-transform:uppercase;color:var(--text-faint);margin-bottom:.9rem}

/* ==========================================================================
   Calculator list — a full-width vertical list of clickable rows, dividers
   only (no cards/boxes): [ symbol | title + description | arrow ]
   ========================================================================== */
.calc-list{margin-top:1.5rem;border-top:1px solid var(--border)}
.calc-row{
  display:grid;
  grid-template-columns:minmax(90px,8.5rem) 1fr minmax(40px,60px);
  grid-template-areas:"symbol content arrow";
  align-items:center;
  gap:1.5rem;
  padding:1.8rem 0;
  text-decoration:none;color:inherit;
  border-bottom:1px solid var(--border);
}
.calc-symbol{
  grid-area:symbol;
  font-family:var(--mono);font-weight:600;   /* fallback text only; rendered KaTeX uses its own fonts */
  font-size:clamp(1.8rem,3vw,2.1rem);
  color:var(--accent);
  transition:color .2s ease;
}
/* KaTeX-rendered symbols (see assets/math-render.js): textbook weight, never wrapped */
.calc-symbol.math-symbol{font-weight:400;white-space:nowrap;line-height:1.2}
.math-symbol .katex{font-size:1em;color:inherit;white-space:nowrap}
.calc-content{grid-area:content;min-width:0}
.calc-title{font-size:clamp(1.3rem,2vw,1.5rem);font-weight:600;color:var(--text);transition:color .2s ease}
.calc-desc{margin-top:.35rem;font-size:1rem;color:var(--text-soft);max-width:60ch}
.calc-arrow{
  grid-area:arrow;display:flex;justify-content:flex-end;
  color:var(--text-faint);
  transition:transform .2s ease,color .2s ease;
}
.calc-arrow svg{width:22px;height:22px}

.calc-row:hover,.calc-row:focus-visible{background:color-mix(in srgb, var(--accent) 6%, transparent)}
.calc-row:hover .calc-title,.calc-row:focus-visible .calc-title{color:var(--accent)}
.calc-row:hover .calc-symbol,.calc-row:focus-visible .calc-symbol{color:var(--accent-hover)}
.calc-row:hover .calc-arrow,.calc-row:focus-visible .calc-arrow{color:var(--accent);transform:translateX(4px)}

@media (max-width:900px){
  .calc-row{grid-template-columns:minmax(72px,96px) 1fr minmax(32px,48px);gap:1.1rem}
}
@media (max-width:640px){
  .calc-row{
    grid-template-columns:1fr auto;
    grid-template-areas:"symbol arrow" "content content";
    row-gap:.7rem;
  }
  .calc-symbol{font-size:1.7rem}
  .calc-desc{max-width:none}
}

/* ==========================================================================
   Method list — a numbered walkthrough of an algorithm's steps (used by the
   probable prime generator's "How it works" card); disabled buttons — for a
   calculator whose work happens off the main thread and takes visible time
   ========================================================================== */
.method-list{padding-left:1.25rem;margin-top:.7rem}
.method-list li{color:var(--text-soft)}
.method-list li + li{margin-top:.5rem}
.method-list li::marker{color:var(--text-faint);font-weight:600}

button:disabled{opacity:.55;cursor:not-allowed}

details{margin-top:1.1rem}
summary{cursor:pointer;font-weight:500;color:var(--accent);list-style:none}
summary::-webkit-details-marker{display:none}
summary::before{content:"▸";display:inline-block;width:1em;transition:transform .15s ease}
details[open] summary::before{transform:rotate(90deg)}
details[open] summary{margin-bottom:.7rem}

/* ==========================================================================
   Text pages (Research, Publications): one quiet reading column, section
   labels, thin rules, and bibliography lists. No cards.
   ========================================================================== */
.prose-page{min-height:100dvh;display:flex;flex-direction:column}
.prose{flex:1;width:100%;max-width:800px;margin:0 auto;padding:clamp(2.6rem,7vw,4.5rem) clamp(1.25rem,4vw,2rem) clamp(3.5rem,9vw,6rem)}
.prose h1{font-size:clamp(1.85rem,4vw,2.6rem);font-weight:600;letter-spacing:-.02em;line-height:1.12}
.prose p{max-width:68ch}
.prose p + p{margin-top:1.15em}
.prose-lead{margin-top:clamp(1.6rem,4vw,2.2rem)}
.prose-section{margin-top:clamp(3.5rem,9vw,5.5rem)}
.section-label{font-size:.78rem;font-weight:500;letter-spacing:.14em;text-transform:uppercase;color:var(--text-faint);margin-bottom:1.5rem}
.section-note{color:var(--text-soft);margin:-.6rem 0 1.6rem}

.research-topic{padding:1.25rem 0;border-top:1px solid var(--border)}
.research-topic:last-child{border-bottom:1px solid var(--border)}
.research-topic h3{font-size:1.02rem;font-weight:600;margin-bottom:.3rem}
.research-topic p{color:var(--text-soft)}

/* Bibliography. <ol reversed> numbers the entries downwards, so the newest
   (first) entry carries the highest number. */
.pub-list{padding-left:2.6rem}
.pub-list-plain{list-style:none;padding-left:0}
.pub{padding:1.05rem 0;border-top:1px solid var(--border)}
.pub:last-child{border-bottom:1px solid var(--border)}
.pub::marker{color:var(--text-faint);font-size:.9rem;font-variant-numeric:tabular-nums}
.pub > span,.pub > cite{display:block}
.pub-year{font-size:.82rem;color:var(--text-faint);font-variant-numeric:tabular-nums;letter-spacing:.02em}
.pub-title{font-style:normal;font-weight:500;color:var(--text)}
.pub-authors{color:var(--text-soft)}
.pub-me{font-weight:600;color:var(--text)}
.pub-role{color:var(--text-faint)}
.pub-venue{color:var(--text-faint);font-size:.95rem}
.pub-link{text-decoration:none;font-weight:500;white-space:nowrap}
.pub-link:hover{text-decoration:underline}
.more-link{margin-top:1.4rem}
.more-link a{text-decoration:none}
.more-link a:hover{text-decoration:underline}

.pub-counts{display:flex;flex-wrap:wrap;gap:1.5rem clamp(2.5rem,8vw,5rem);margin-top:clamp(2.2rem,6vw,3.2rem)}
.pub-count{display:block;text-decoration:none;color:inherit}
.pub-count-n{display:block;font-size:clamp(2.2rem,6vw,3rem);font-weight:600;letter-spacing:-.02em;line-height:1.1;font-variant-numeric:tabular-nums}
.pub-count-l{display:block;font-size:.87rem;color:var(--text-faint);margin-top:.2rem}
.pub-count:hover .pub-count-l{color:var(--accent)}

.text-links{margin-top:clamp(4rem,10vw,6.5rem);display:flex;flex-wrap:wrap;justify-content:center;gap:.35rem .9rem;color:var(--text-faint)}
.text-links a{text-decoration:none;border-bottom:1px solid transparent}
.text-links a:hover{border-bottom-color:currentColor}

@media (max-width:640px){
  .pub-list{padding-left:2.1rem}
}

/* ==========================================================================
   Footer
   ========================================================================== */
footer{border-top:1px solid var(--border);background:var(--surface-2)}
.foot{display:flex;gap:1rem;flex-wrap:wrap;padding:1.3rem 0 2.2rem;font-size:.87rem;color:var(--text-faint)}
.foot a{color:var(--text-soft);text-decoration:none}

/* ==========================================================================
   Print
   ========================================================================== */
@media print{
  :root{--bg:#fff;--surface:#fff;--text:#000;--border:#bbb}
  .topbar,.side,.actions,.copy,footer,.theme-btn{display:none}
  .layout{display:block}
  .card{box-shadow:none;break-inside:avoid}
}

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

/* ==========================================================================
   Mathematics (KaTeX, self-hosted; see assets/math-render.js).
   .math-inline  sits in prose or a table cell, inheriting its colour and size
   .math-display a formula on its own line: left-aligned, scrolls inside its own box on narrow screens
   ========================================================================== */
.math-inline{color:inherit;white-space:nowrap}
.math-inline .katex{font-size:1.12em;color:inherit;white-space:nowrap}
.math-display{display:block;max-width:100%;margin:.55rem 0;padding:.2rem 0;overflow-x:auto;overflow-y:hidden;color:var(--text)}
.math-display .katex-display{margin:0;text-align:left}
.math-display .katex-display>.katex{text-align:left;font-size:1.12em}
.math-display .katex{color:inherit}
/* result lines that hold typeset math: keep them inside the card, scrolling sideways rather than widening the page */
.readout .expr,.readout .identity,.fn-formula>div,.pc-def{max-width:100%;overflow-x:auto;overflow-y:hidden}
.readout .expr .math-inline .katex{font-size:1.3em}
.readout .identity .math-inline .katex{font-size:1.05em}
/* the calculators' variable labels and buttons */
label .math-inline .katex,.stat dt .math-inline .katex,th .math-inline .katex{font-size:1.15em}
.presets .math-inline .katex{font-size:1.02em}
th .math-inline{text-transform:none;letter-spacing:normal}
.presets button .math-inline{white-space:nowrap}
.fn-formula .math-inline .katex{font-size:1.05em}
/* a display block that is not (yet, or ever) typeset shows its fallback lines as written */
.math-display:not([data-math-rendered]){white-space:pre-wrap;overflow-wrap:anywhere}
.math-display.pc-def{font-family:inherit;font-size:1rem;color:var(--text)}

/* Linear congruence solver */
.lc-status{margin-top:.2rem;font-size:.74rem;font-weight:600;letter-spacing:.09em;text-transform:uppercase;color:var(--text-soft)}
.lc-out{min-width:0}
.lc-value{margin-top:.35rem;max-width:100%;overflow-x:auto;overflow-y:hidden;font-size:clamp(1.3rem,3.5vw,1.9rem);font-family:var(--serif,inherit)}
.lc-value .math-inline .katex{font-size:1em}
.readout .identity.math-inline{display:block}
.readout .identity .katex{font-size:1.1em}
.lc-list{font-family:var(--mono);font-size:.88rem;color:var(--text-soft);overflow-wrap:anywhere;line-height:1.7;max-height:14rem;overflow:auto;background:var(--surface-2);border-radius:10px;padding:.8rem .95rem;margin-top:.5rem}
.lc-steps li>.math-display{margin:.4rem 0}
/* an inline formula that is not typeset (too long, or KaTeX unavailable) is plain text and must wrap */
.math-inline:not([data-math-rendered]){white-space:normal;overflow-wrap:anywhere}
.math-display{position:relative}
.lc-steps li,#result-note,#list-label,.lc-status{overflow-wrap:anywhere}
.katex{text-transform:none}
/* long integers inside prose must wrap rather than widen the page; proof tables scroll inside their wrapper instead of breaking digits */
.notes{overflow-wrap:anywhere}
.pr-table td,.pr-table th{white-space:nowrap;overflow-wrap:normal}
#trace-body td:first-child{white-space:normal;min-width:15rem}

/* ---------- skip link: the first stop for the keyboard, visible only when it has the focus ---------- */
.skip-link{position:absolute;left:.75rem;top:-4rem;z-index:100;padding:.55rem .9rem;font-size:.92rem;font-weight:600;color:var(--accent-on);background:var(--accent);border-radius:8px;text-decoration:none}
.skip-link:focus{top:.6rem;outline:2px solid var(--text);outline-offset:2px}
@media print{.skip-link{display:none}}