/* MathSolver.site design system — original. Mobile-first. */
:root{
  --ink:#1C2430; --paper:#FAF9F5; --card:#FFFFFF;
  --teal:#0E7C6B; --teal-dark:#0A5F53;
  --amber:#E8A317; --slate:#5B6675; --line:#E5E1D8;
  --success:#15803D; --error:#B91C1C;
  --radius:14px; --maxw:1120px; --toolw:720px;
  --font-body:-apple-system,BlinkMacSystemFont,"Segoe UI",Inter,Roboto,"Helvetica Neue",Arial,sans-serif;
  --font-display:"Fraunces",Georgia,"Times New Roman",serif;
  --font-mono:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--font-body);font-size:17px;line-height:1.65;-webkit-font-smoothing:antialiased}
h1,h2,h3{font-family:var(--font-display);line-height:1.25;letter-spacing:-.01em;margin:0 0 .6em}
h1{font-size:clamp(1.9rem,4.5vw,2.9rem)}
h2{font-size:clamp(1.4rem,3vw,1.9rem);padding-top:.4em}
h2 .rule{display:block;width:52px;height:4px;background:var(--amber);border-radius:2px;margin-top:.35em}
p{margin:0 0 1em}
a{color:var(--teal);text-decoration:underline;text-underline-offset:3px}
a:hover{color:var(--teal-dark)}
img,svg{max-width:100%;height:auto}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 20px}
.skip{position:absolute;left:-9999px;top:0;background:var(--ink);color:#fff;padding:10px 16px;z-index:100;border-radius:0 0 8px 0}
.skip:focus{left:0}

/* Header */
.site-header{background:var(--card);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:50}
.site-header .wrap{display:flex;align-items:center;gap:24px;height:68px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink);font-family:var(--font-display);font-weight:600;font-size:1.35rem}
.brand .dot{color:var(--slate);font-weight:400}
.brand svg{width:34px;height:34px}
.main-nav{margin-left:auto;display:flex;gap:4px;align-items:center}
.main-nav a.nav-link{color:var(--ink);text-decoration:none;font-weight:500;padding:10px 14px;border-radius:10px}
.main-nav a.nav-link:hover{background:#F1EEE6}
.nav-toggle{display:none;background:none;border:1px solid var(--line);border-radius:10px;padding:10px 12px;font-size:1.1rem;cursor:pointer;color:var(--ink)}
@media(max-width:860px){
  .main-nav{display:none;position:absolute;top:68px;left:0;right:0;background:var(--card);flex-direction:column;align-items:stretch;padding:12px 20px 20px;border-bottom:1px solid var(--line);box-shadow:0 12px 24px rgba(0,0,0,.08)}
  .main-nav.open{display:flex}
  .nav-toggle{display:block;margin-left:auto}
}

/* Breadcrumbs */
.crumbs{font-size:.85rem;color:var(--slate);margin:18px 0 6px}
.crumbs a{color:var(--slate);text-decoration:none}
.crumbs a:hover{text-decoration:underline}
.crumbs [aria-current]{color:var(--ink);font-weight:600}

/* Calculator widget — the core component */
.tool{max-width:var(--toolw);margin:26px auto 8px;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:0 6px 24px rgba(28,36,48,.07);overflow:hidden}
.tool-head{padding:22px 24px 0}
.tool-head h1{margin-bottom:.25em}
.tool-lede{color:var(--slate);margin:0 0 .5em}
.tool-body{padding:6px 24px 24px}
.field{margin:14px 0}
.field label{display:block;font-weight:600;margin-bottom:6px}
.field .hint{font-weight:400;color:var(--slate);font-size:.88rem;display:block;margin-top:4px}
.field input,.field select{width:100%;padding:14px;font-size:1.05rem;border:2px solid var(--line);border-radius:10px;font-family:var(--font-mono);background:#fff;color:var(--ink)}
.field input:focus,.field select:focus{outline:3px solid rgba(14,124,107,.28);border-color:var(--teal)}
.field-row{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:12px}
@media(max-width:520px){.field-row{grid-template-columns:1fr}}
.btn-row{display:flex;gap:12px;margin:20px 0 6px;flex-wrap:wrap}
.btn{appearance:none;border:none;cursor:pointer;font-size:1.05rem;font-weight:700;padding:14px 28px;border-radius:10px;min-height:52px;font-family:var(--font-body)}
.btn-primary{background:var(--teal);color:#fff}
.btn-primary:hover{background:var(--teal-dark)}
.btn-primary:focus-visible,.btn-ghost:focus-visible{outline:3px solid var(--amber);outline-offset:2px}
/* Audit 2026-10-12 (F-A5): visible focus on JS-built controls */
#ms-chat-btn:focus-visible,#ms-chat-close:focus-visible,.ms-tab:focus-visible,.ms-mp-key:focus-visible{outline:3px solid var(--amber);outline-offset:2px}
.card-title{font-size:1.05rem;margin:0 0 4px}
.btn-ghost{background:transparent;color:var(--teal);border:2px solid var(--teal)}
.btn-ghost:hover{background:#EFF7F5}
.fielderr{color:var(--error);font-size:.92rem;margin-top:6px;display:none}
.fielderr.show{display:block}
.result{display:none;margin-top:18px;border:2px solid #BBE3C9;background:#F2FAF4;border-radius:12px;padding:20px 22px}
.result.show{display:block}
.result .answer{font-family:var(--font-mono);font-size:1.7rem;font-weight:700;margin:.2em 0 .4em}
.verified{display:inline-flex;align-items:center;gap:6px;background:var(--success);color:#fff;font-size:.8rem;font-weight:700;padding:4px 12px;border-radius:999px;letter-spacing:.02em}
.steps{margin:18px 0 0;padding:0;list-style:none}
.steps li{position:relative;padding:18px 20px 18px 110px;border:1px solid var(--line);border-radius:12px;margin-bottom:12px;background:var(--card)}
.steps .snum{position:absolute;left:16px;top:18px;background:var(--teal);color:#fff;font-size:.78rem;font-weight:700;padding:5px 12px;border-radius:20px;white-space:nowrap}
.steps .stitle{font-weight:700;font-size:1rem;margin-bottom:6px;color:var(--ink)}
.steps .smath{font-family:var(--font-mono);background:#F4F1E9;padding:8px 12px;border-radius:8px;margin:6px 0;overflow-x:auto;font-size:1.02rem}
.steps .snote{color:var(--slate);font-size:.93rem}

/* Content sections */
.prose{max-width:var(--toolw);margin:0 auto;padding:10px 0 30px}
.callout{background:#FFF8E8;border:1px solid #F0DDA6;border-left:5px solid var(--amber);border-radius:10px;padding:16px 20px;margin:1.4em 0}
.callout.mistakes{background:#FDF2F2;border-color:#F3C1C1;border-left-color:var(--error)}
.callout h3{margin-top:0;font-size:1.15rem}
.formula-box{background:var(--ink);color:#fff;border-radius:12px;padding:20px 24px;margin:1.4em 0;text-align:center;font-family:var(--font-mono);font-size:1.25rem;overflow-wrap:anywhere;max-width:100%;box-sizing:border-box}

/* FAQ accordion */
.faq{border-top:1px solid var(--line);margin-top:1em}
.faq-item{border-bottom:1px solid var(--line)}
.faq-q{width:100%;background:none;border:none;text-align:left;font-size:1.05rem;font-weight:600;padding:16px 40px 16px 0;cursor:pointer;position:relative;color:var(--ink);font-family:var(--font-body)}
.faq-q::after{content:"+";position:absolute;right:8px;top:14px;font-size:1.5rem;color:var(--teal);font-weight:400}
.faq-q[aria-expanded="true"]::after{content:"–"}
.faq-a{display:none;padding:0 0 18px;color:var(--ink)}
.faq-a.open{display:block}

/* Related tools */
.related{margin:2.5em 0}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:16px;margin-top:1em}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:20px;text-decoration:none;color:var(--ink);display:block;transition:transform .15s,box-shadow .15s}
.card:hover{transform:translateY(-2px);box-shadow:0 8px 20px rgba(28,36,48,.1);color:var(--ink)}
.card h3{font-size:1.1rem;margin:0 0 .3em;color:var(--teal-dark)}
.card p{font-size:.92rem;color:var(--slate);margin:0}

/* Hub pages */
.hub-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:18px;margin:1.6em 0}
.hero{background:var(--ink);color:#fff;border-radius:18px;padding:clamp(28px,5vw,56px);margin:22px 0;text-align:center}
.hero h1{color:#fff}
.hero p{color:#CBD5E1;max-width:640px;margin:0 auto 1.4em}
.hero .tagline{color:var(--amber);font-weight:600;letter-spacing:.04em;text-transform:uppercase;font-size:.85rem;margin-bottom:.8em}

/* Ad slots — reserved, labeled, empty at launch */
.adslot{max-width:var(--toolw);margin:26px auto;min-height:110px;border:1px dashed var(--line);border-radius:10px;display:flex;align-items:center;justify-content:center;color:var(--slate);font-size:.8rem;letter-spacing:.08em;text-transform:uppercase;background:#F5F3EC}
.adslot.wide{max-width:var(--maxw)}

/* Footer */
.site-footer{background:var(--ink);color:#CBD5E1;margin-top:60px;padding:48px 0 28px}
.site-footer .cols{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:28px}
@media(max-width:760px){.site-footer .cols{grid-template-columns:1fr 1fr}}
.site-footer h4,.site-footer .fhead{color:#fff;font-size:.95rem;margin:0 0 .8em;font-family:var(--font-body);text-transform:uppercase;letter-spacing:.06em}
.site-footer a{color:#CBD5E1;text-decoration:none;font-size:.93rem}
.site-footer a:hover{color:#fff;text-decoration:underline}
.site-footer ul{list-style:none;margin:0;padding:0}
.site-footer li{margin:.45em 0}
.site-footer .fine{border-top:1px solid #334155;margin-top:32px;padding-top:20px;font-size:.85rem;color:#94A3B8;display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px}

/* 404 */
.center{text-align:center;padding:60px 0}table.data{width:100%;border-collapse:collapse;margin:1.2em 0;font-size:.95rem}
table.data th,table.data td{border:1px solid var(--line);padding:10px 14px;text-align:left}
table.data th{background:#F1EEE6;font-family:var(--font-display)}

/* Graphing calculator */
.graph-wrap{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;margin:26px auto;max-width:var(--toolw);box-shadow:0 6px 24px rgba(28,36,48,.07)}
.graph-wrap canvas{display:block;width:100%;touch-action:none;cursor:grab;border-bottom:1px solid var(--line)}
.graph-wrap canvas:active{cursor:grabbing}
.graph-wrap canvas:focus-visible{outline:3px solid var(--amber);outline-offset:-3px}
.graph-controls{display:flex;gap:10px;flex-wrap:wrap;align-items:center;padding:14px 18px}
.graph-controls .btn{min-height:44px;padding:10px 18px;font-size:.95rem}
.graph-readout{font-family:var(--font-mono);font-size:.95rem;color:var(--slate);padding:0 18px 6px;min-height:1.6em}
.graph-table{padding:6px 18px 18px;overflow-x:auto}
.graph-table table{margin:0}

/* Universal solver */
.solver-hero{max-width:var(--toolw);margin:6px auto 8px}
.solver-form{display:flex;gap:10px;margin:18px 0 10px}
.solver-form input[type=text]{flex:1;font-size:1.15rem;padding:14px 18px;border:2px solid var(--line);border-radius:10px;font-family:var(--font-mono);min-width:0}
.solver-form input[type=text]:focus{border-color:var(--teal);outline:none;box-shadow:0 0 0 3px rgba(14,124,107,.15)}
.solver-examples{display:flex;gap:8px;flex-wrap:wrap;margin:0 0 6px}
.solver-examples button{background:#fff;border:1px solid var(--line);border-radius:20px;padding:7px 14px;font-size:.88rem;cursor:pointer;font-family:var(--font-mono);color:var(--slate)}
.solver-examples button:hover{border-color:var(--teal);color:var(--teal)}
.solver-out{margin-top:8px}
.solver-answer{background:#EFF7F5;border:1px solid #BFE3DC;border-radius:12px;padding:18px 22px;margin:16px 0}
.solver-answer-label{font-size:.8rem;text-transform:uppercase;letter-spacing:.08em;color:var(--teal);font-weight:700}
.solver-answer-val{font-family:var(--font-mono);font-size:1.7rem;font-weight:700;margin-top:6px;overflow-x:auto}
.solver-error{background:#FDF2F2;border:1px solid #F3C1C1;border-radius:10px;padding:16px 20px;margin:16px 0}
.solver-scope{font-size:.92rem;color:var(--slate)}
@media(max-width:560px){.solver-form{flex-direction:column}.solver-answer-val{font-size:1.35rem}}

/* Visually hidden (screen-reader accessible labels) */
.vh{position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}

/* === WP migration fixes (v2.0.1) === */
/* Nav: proper list reset (wp_nav_menu outputs ul/li) */
.main-nav ul.nav-list { list-style: none; margin: 0; padding: 0; display: flex; gap: 4px; align-items: center; }
.main-nav ul.nav-list li { list-style: none; margin: 0; padding: 0; }
/* Card inner elements as spans (block elements inside <a> get stripped by WP filters) */
.card .ctitle { display: block; font-family: var(--font-display); font-weight: 600; font-size: 1.05rem; color: var(--ink); margin-bottom: 6px; }
.card .cdesc { display: block; font-size: .92rem; color: var(--slate); }
/* Hide ad placeholders until ads are live */
.adslot { display: none; }
/* Hero contrast fixes */
.hero .tagline { color: #BFE8DF; }
.hero .solver-scope { color: #D7F0EA; }
.hero .btn-ghost { color: #fff; border-color: rgba(255,255,255,.55); }
.hero .btn-ghost:hover { background: rgba(255,255,255,.12); }
.hero .solver-examples button { color: #EAF7F4; border-color: rgba(255,255,255,.35); background: rgba(255,255,255,.08); }

/* === Mega menu (v2.0.4) === */
.nav-list > li.has-mega { position: relative; }
.nav-link .caret { font-size: .7em; margin-left: 2px; }
.mega {
  display: none; position: absolute; top: 100%; left: 0; z-index: 200;
  background: var(--card); border: 1px solid var(--line); border-radius: 14px;
  box-shadow: 0 18px 44px rgba(15,40,36,.16); padding: 18px 22px;
  grid-template-columns: repeat(4, minmax(150px, 1fr)); gap: 18px; min-width: 640px;
}
.has-mega:hover .mega, .has-mega:focus-within .mega { display: grid; }
.mega-col { display: flex; flex-direction: column; gap: 2px; }
.mega-head { font-weight: 700; color: var(--teal); font-size: .92rem; padding: 6px 8px; border-radius: 8px; text-decoration: none; }
.mega-head:hover { background: #EAF5F1; }
.mega-col a:not(.mega-head) { color: var(--ink); text-decoration: none; font-size: .9rem; padding: 5px 8px; border-radius: 8px; }
.mega-col a:not(.mega-head):hover { background: #F4F1E8; color: var(--teal); }
@media (max-width: 900px) {
  .has-mega .mega { position: static; display: none; box-shadow: none; border: 0; padding: 6px 0 6px 12px; min-width: 0; grid-template-columns: 1fr; }
  .has-mega.mega-open .mega { display: grid; }
}

/* === Readability hardening (v2.1.1): explicit dark text on all result/step elements.
   Protects against forced-dark-mode inversions that left white text on light boxes. */
.result, .result .answer, .steps li, .steps .stitle,
.steps .smath, .steps .snote, .tool-out, .solver-out {
  color: #1C2430;
}
.steps .smath { color: #1C2430; }
.result .answer { color: #0E5C4F; }
.solver-out .answer { color: #0E5C4F; }
/* Keep verified badge readable */
.verified { color: #fff; }

/* === Professional polish (v2.1.2): explicit colors on remaining dynamic elements */
.solver-answer, .solver-answer-val, .solver-answer-label { color: #1C2430; }
.solver-answer-val { color: #0E5C4F; }
.solver-error { color: #1C2430; }
.quiz-q, .quiz-opt, .quiz-feedback, .quiz-score { color: #1C2430; }
.tool-body, .tool-head, .field label { color: #1C2430; }
.prose, .prose p, .prose li { color: #1C2430; }
.prose .snote, .tool-lede, .field .hint { color: #5B6675; }

/* === Mobile fixes (v2.1.4) === */
/* 1. Hamburger menu: stack nav links vertically on mobile */
@media(max-width:860px){
  .main-nav ul.nav-list{flex-direction:column;align-items:stretch;gap:2px;width:100%}
  .main-nav ul.nav-list li{width:100%}
  .main-nav a.nav-link{display:block;padding:14px 16px;min-height:48px}
}
/* 2. Mega menu takes full panel width on mobile */
@media(max-width:900px){
  .has-mega{width:100%}
  .has-mega .mega{width:100%;box-sizing:border-box}
  .mega-col a:not(.mega-head){padding:10px 12px;min-height:44px;display:flex;align-items:center}
  .mega-head{padding:12px 8px;min-height:44px;display:flex;align-items:center}
}
/* 3. Graphing canvas: maintain aspect ratio on mobile */
@media(max-width:560px){
  .graph-wrap canvas{height:auto!important;aspect-ratio:4/3}
}
/* 4. Larger tap targets */
.solver-examples button{min-height:44px;padding:10px 16px}
@media(max-width:860px){
  .site-footer a{display:inline-block;padding:8px 0;min-height:44px}
}
/* 5. Tables never overflow on mobile */
.table-wrap{overflow-x:auto;-webkit-overflow-scrolling:touch}
@media(max-width:560px){
  table.data{display:block;overflow-x:auto;white-space:nowrap}
}
/* 6. Long answers wrap on narrow screens */
@media(max-width:520px){
  .result .answer{font-size:1.35rem;overflow-wrap:break-word}
  .solver-answer-val{font-size:1.25rem}
}

/* === SEO/AI optimization (v2.2.0): Quick Answer boxes for AI citations + featured snippets */
.quick-answer{background:#EFF7F5;border:2px solid #0E7C6B;border-radius:12px;padding:18px 22px;margin:0 0 1.6em}
.quick-answer .qa-label{font-size:.78rem;text-transform:uppercase;letter-spacing:.08em;color:#0E7C6B;font-weight:700;margin-bottom:8px}
.quick-answer p{margin:0;font-size:1.02rem;line-height:1.7;color:#1C2430}
.quick-answer strong{color:#0E5C4F}

/* === Hero CTA buttons: stack on mobile, no overlap (v2.3.1) === */
.hero-ctas{display:flex;gap:12px;justify-content:center;flex-wrap:wrap}
.hero-ctas .btn{white-space:nowrap}
@media(max-width:560px){
  .hero-ctas{flex-direction:column;align-items:stretch}
  .hero-ctas .btn{width:100%;text-align:center}
}



/* === MathSolver Assistant v2 (bottom-left, avoids Hostinger Agent overlap) === */
#ms-chat{position:fixed;bottom:20px;left:20px;z-index:9998;font-family:inherit}
#ms-chat-btn{width:58px;height:58px;border-radius:50%;border:none;background:linear-gradient(135deg,#0E7C6B,#0B2B4E);color:#fff;font-size:26px;cursor:pointer;box-shadow:0 4px 18px rgba(14,124,107,.45);transition:transform .15s;position:relative}
#ms-chat-btn:hover{transform:scale(1.07)}
#ms-chat-btn .ms-pulse{position:absolute;inset:-4px;border-radius:50%;border:2px solid #0E7C6B;opacity:0;animation:msPulse 2.4s infinite}
@keyframes msPulse{0%{transform:scale(.85);opacity:.7}70%{transform:scale(1.12);opacity:0}100%{opacity:0}}
#ms-chat-btn.ms-open .ms-pulse{display:none}
#ms-chat-panel{position:absolute;bottom:70px;left:0;width:min(380px,calc(100vw - 40px));height:500px;max-height:72vh;background:#fff;border-radius:18px;box-shadow:0 12px 48px rgba(11,43,78,.28);display:flex;flex-direction:column;overflow:hidden;border:1px solid #E5E0D5}
#ms-chat-panel[hidden]{display:none}
#ms-chat-head{background:linear-gradient(135deg,#0B2B4E,#0E7C6B);color:#fff;padding:14px 18px;font-size:.95rem;display:flex;justify-content:space-between;align-items:center}
#ms-chat-close{background:rgba(255,255,255,.15);border:none;color:#fff;font-size:15px;cursor:pointer;width:30px;height:30px;border-radius:50%;line-height:1}
#ms-chat-msgs{flex:1;overflow-y:auto;padding:16px 14px;display:flex;flex-direction:column;gap:10px;background:#F8F6F0}
.ms-msg{max-width:90%;padding:10px 15px;border-radius:15px;font-size:.92rem;line-height:1.6;word-wrap:break-word;animation:msFade .25s}
@keyframes msFade{from{opacity:0;transform:translateY(6px)}to{opacity:1}}
.ms-user{align-self:flex-end;background:#0E7C6B;color:#fff;border-bottom-right-radius:5px}
.ms-bot{align-self:flex-start;background:#fff;color:#1C2430;border:1px solid #E5E0D5;border-bottom-left-radius:5px;box-shadow:0 1px 4px rgba(0,0,0,.05)}
.ms-bot a{color:#0E7C6B;font-weight:600}
.ms-answer{font-size:1.08rem;background:#EFF7F5;border-radius:10px;padding:10px 12px;margin-bottom:8px}
.ms-step{padding:5px 0 5px 12px;border-left:3px solid #0E7C6B;margin:6px 0;font-size:.88rem}
.ms-verified{margin-top:8px;font-size:.78rem;color:#0E5C4F}
/* typing indicator */
.ms-typing{display:flex;gap:5px;padding:14px 18px}
.ms-typing span{width:8px;height:8px;border-radius:50%;background:#0E7C6B;opacity:.35;animation:msBlink 1.2s infinite}
.ms-typing span:nth-child(2){animation-delay:.2s}.ms-typing span:nth-child(3){animation-delay:.4s}
@keyframes msBlink{0%,60%,100%{opacity:.25;transform:none}30%{opacity:1;transform:translateY(-3px)}}
/* follow-up chips */
#ms-chat-follow{display:flex;gap:8px;padding:10px 12px;background:#fff;border-top:1px solid #E5E0D5;overflow-x:auto}
#ms-chat-follow button{flex-shrink:0;background:#EFF7F5;border:1px solid #0E7C6B;color:#0E5C4F;border-radius:20px;padding:7px 15px;font-size:.82rem;cursor:pointer;transition:all .15s}
#ms-chat-follow button:hover{background:#0E7C6B;color:#fff}
#ms-chat-form{display:flex;gap:8px;padding:12px;background:#fff;border-top:1px solid #E5E0D5}
#ms-chat-in{flex:1;border:2px solid #E5E0D5;border-radius:12px;padding:11px 15px;font-size:.94rem;font-family:inherit;min-width:0}
#ms-chat-in:focus{outline:none;border-color:#0E7C6B}
#ms-chat-form button{background:#0E7C6B;color:#fff;border:none;border-radius:12px;padding:0 20px;font-size:18px;cursor:pointer;transition:background .15s}
#ms-chat-form button:hover{background:#0B5C4F}
@media(max-width:560px){#ms-chat{bottom:16px;left:16px}#ms-chat-panel{bottom:68px;height:min(520px,72vh)}}

/* === World-class polish: cards + buttons (v2.5.1) === */
/* Equal-height cards in grid */
.cards{align-items:stretch}
.card{display:flex;flex-direction:column;height:100%}
.card .cdesc{flex:1}
/* CTA buttons: generous padding, never cramped */
.btn-cta{display:inline-flex;align-items:center;gap:10px;padding:16px 32px;line-height:1.5;white-space:normal;text-align:center}
a.btn-cta{text-decoration:none}
/* Fix underline-only buttons that look cramped */
.prose a.btn-cta{border-bottom:none}
/* Outlined CTA links: ensure comfortable padding everywhere */
.prose a[class*="btn"], .prose a.cta-link{
  display:inline-block;padding:14px 28px;line-height:1.6;
  border:2px solid var(--teal);border-radius:12px;
  text-decoration:none;font-weight:700;
}

/* === Math Input Panel — matches site color scheme (teal/cream) === */
#ms-math-panel{position:fixed;z-index:10000;background:#FFFDF8;border:2px solid #0E7C6B;border-radius:16px;box-shadow:0 12px 48px rgba(11,43,78,.25);width:330px;max-width:calc(100vw - 16px);overflow:hidden;color:#1C2430}
.ms-mp-tabs{display:flex;gap:4px;padding:10px 10px 0;overflow-x:auto;border-bottom:1px solid #E5E0D5}
.ms-mp-tabs button{background:none;border:none;color:#6B7280;font-size:.82rem;font-weight:600;padding:8px 14px;border-radius:10px 10px 0 0;cursor:pointer;white-space:nowrap}
.ms-mp-tabs button.active{background:#EFF7F5;color:#0E7C6B;border-bottom:2px solid #0E7C6B}
.ms-mp-tabs button:hover{color:#0E7C6B}
.ms-mp-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:8px;padding:12px;background:#FFFDF8}
.ms-mp-key{background:#F8F6F0;border:1px solid #E5E0D5;border-radius:12px;padding:12px 4px;cursor:pointer;transition:all .12s;color:#1C2430}
.ms-mp-key:hover{background:#0E7C6B;border-color:#0E7C6B;transform:translateY(-1px)}
.ms-mp-key:hover .ms-mp-sym{color:#fff}
.ms-mp-sym{font-size:1.05rem;font-weight:600;color:#0E5C4F}
.ms-math-btn{display:inline-flex;align-items:center;gap:6px;background:#EFF7F5;color:#0E7C6B;border:2px solid #0E7C6B;border-radius:10px;padding:10px 16px;font-size:.9rem;font-weight:700;cursor:pointer}
.ms-math-btn:hover{background:#0E7C6B;color:#fff}

/* === Professional step-by-step (competitor-grade) === */
.ms-steps-head{font-size:1.05rem;font-weight:700;color:var(--ink);margin:1.2em 0 .6em;padding-bottom:.4em;border-bottom:2px solid var(--teal)}
/* (Duplicate .steps block removed in audit 2026-10-12; single definition now lives near line 76.) */
.solver-answer{background:#EFF7F5;border:2px solid #0E7C6B;border-radius:14px;padding:22px 26px;margin-bottom:6px;color:#1C2430}
.solver-answer-label{font-size:.78rem;text-transform:uppercase;letter-spacing:.1em;color:#0E7C6B;font-weight:700}
.solver-answer-val{font-size:1.5rem;font-weight:700;margin-top:6px;font-family:var(--font-mono);color:#0B2B4E}

/* === Image solver tabs === */
.ms-tab{background:#F8F6F0;border:1px solid var(--line);border-radius:10px;padding:10px 20px;font-size:.92rem;font-weight:600;cursor:pointer;color:var(--slate)}
.ms-tab.active{background:var(--teal);color:#fff;border-color:var(--teal)}

/* === Σ button on calculator forms === */
.ms-math-calc-btn{padding:8px 14px;font-size:1rem;margin:6px 4px 6px 0;vertical-align:middle}
.tool-form .ms-math-calc-btn{order:-1}

/* Σ button: own row above Calculate */
.ms-math-row{display:block;width:100%;margin:4px 0 12px}
.ms-math-row .ms-math-btn{margin:0}

/* Visually-hidden text for screen readers (accessible labels) */
.visually-hidden{position:absolute;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}

/* === Mobile-first answer interface (answer display only) ===
   Final answer prominent, no horizontal overflow on a 360px viewport,
   steps wrap cleanly, buttons thumb-friendly. */
.result{box-sizing:border-box;max-width:100%;overflow-wrap:break-word}
.result .answer{overflow-wrap:break-word;word-break:break-word;line-height:1.5;max-width:100%}
.result .answer .final-answer{display:block;font-size:1.5rem;line-height:1.4;overflow-wrap:break-word}
.result code{max-width:100%;box-sizing:border-box;overflow-wrap:anywhere;word-break:break-word;white-space:pre-wrap}
.steps li{overflow-wrap:break-word;word-break:break-word;max-width:100%;box-sizing:border-box}
.steps .smath{overflow-x:hidden;overflow-wrap:anywhere;word-break:break-word;white-space:normal}
.steps .snote{overflow-wrap:break-word}
@media(max-width:560px){
  .result{padding:16px 14px}
  .result .answer{font-size:1.3rem}
  .result .answer .final-answer{font-size:1.3rem}
  /* Stack the step badge above the step text: the 110px left gutter would
     leave almost no room for step content on a 360px screen. */
  .steps li{padding:14px 14px}
  .steps .snum{position:static;display:inline-block;margin-bottom:8px}
  /* Thumb-friendly calculator buttons: full-width stacked targets. */
  .tool-form .btn-row{flex-direction:column}
  .tool-form .btn-row .btn{width:100%}
}

/* === GOAT (v81): TRUE zero horizontal overflow at 360px on every page ===
   overflow-x: clip (not hidden) so the sticky header keeps working, and
   containment on every content container that can carry a wide table,
   code block, or long formula. Answer-display only: no layout, font,
   spacing, or colour changes to the existing design. */
html, body { overflow-x: hidden; overflow-x: clip; }
.prose, .tool-body, .tool-head, .wrap, .site-footer .wrap { min-width: 0; }
.prose table, .tool-body table, .result table { display: block; max-width: 100%; overflow-x: auto; box-sizing: border-box; }
.prose pre, .prose code, .tool-body pre, .tool-body code, .solver-out code, .solver-out pre { overflow-wrap: anywhere; word-break: break-word; white-space: pre-wrap; max-width: 100%; box-sizing: border-box; }
.prose img, .prose iframe, .prose video, .prose embed, .prose object { max-width: 100%; }
.crumbs, .tool-lede, .field .hint { overflow-wrap: anywhere; }
.field-row > *, .tool-form > *, .result > * { min-width: 0; }
.solver-out, .tool-out { overflow-wrap: anywhere; }
.solver-answer-val { overflow-wrap: anywhere; word-break: break-word; }

/* === GOAT (v81): answer-display elements (badge, trust line, practice,
   exact/decimal toggle, diagnose) — answer display only === */
.ms-answer-label{font-size:.8rem;text-transform:uppercase;letter-spacing:.08em;color:var(--teal);font-weight:700;margin-bottom:4px}
.ms-trust{font-size:.82rem;color:var(--slate);margin:6px 0 10px}
.ms-ed-toggle{display:flex;gap:6px;margin:10px 0 4px}
.ms-ed-toggle button{background:#F8F6F0;border:1px solid var(--line);border-radius:999px;padding:7px 16px;font-size:.88rem;font-weight:600;cursor:pointer;color:var(--slate)}
.ms-ed-toggle button.active{background:var(--teal);color:#fff;border-color:var(--teal)}
.ms-practice{margin-top:22px;border-top:1px solid var(--line);padding-top:16px}
.ms-practice h3{font-size:1.05rem;margin-bottom:6px}
.ms-practice ol{padding-left:22px}
.ms-practice li{margin-bottom:14px}
.ms-practice-row{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin-top:6px}
.ms-practice-row input[type="text"]{width:170px;max-width:100%;padding:10px 12px;font-size:.95rem;border:2px solid var(--line);border-radius:10px;font-family:var(--font-mono)}
.ms-practice-row .btn{padding:8px 14px;font-size:.9rem}
.ms-practice-row span{font-size:.9rem;font-weight:600}
.ms-practice-hint{font-size:.85rem;color:var(--slate);margin-top:4px}
.ms-practice [data-ms-quiz]{margin-top:14px}
.ms-practice [data-ms-quiz] ol{padding-left:22px}
.ms-practice [data-ms-quiz] li{margin-bottom:10px}
.ms-practice [data-ms-quiz] input[type="text"]{width:170px;max-width:100%;padding:10px 12px;font-size:.95rem;border:2px solid var(--line);border-radius:10px;font-family:var(--font-mono);margin-top:4px}
.ms-practice [data-ms-quiz-score]{font-weight:700;margin-top:10px}
.ms-diagnose{margin-top:22px;border:1px solid var(--line);border-radius:12px;padding:16px 18px;background:#F8F6F0}
.ms-diagnose h3{font-size:1.05rem;margin-bottom:4px}
.ms-diagnose p{margin:0 0 10px;color:var(--slate);font-size:.95rem}
.ms-diagnose [data-ms-diagnose-out]{margin-top:12px}
.ms-diagnose [data-ms-diagnose-out] p{color:var(--ink);margin:0 0 8px}
@media(max-width:560px){
  .ms-practice-row input[type="text"], .ms-practice [data-ms-quiz] input[type="text"]{width:100%}
  .ms-diagnose{padding:14px}
}

/* === v82: 360px tab-row safety ===
   The photo page now has THREE tabs (Upload / Draw / Type it yourself).
   The tab row is flex with no wrap, so at 360px the third tab would be
   cut off (html/body overflow-x:clip hides it instead of scrolling).
   Wrap the row + the exact/decimal toggle row, and let tab labels wrap. */
.ms-tabs{flex-wrap:wrap}
.ms-tab{max-width:100%;overflow-wrap:anywhere}
.ms-ed-toggle{flex-wrap:wrap}

/* === v97: Answer interface redesign (owner order 2026-10-24) ===
   One hero answer everywhere, serif math, compact left-aligned steps,
   result actions (Copy answer / Copy steps / New problem), and no more
   sticky-header clipping of the result box. Site palette unchanged. */
.result, .solver-out { scroll-margin-top: 96px; }
.solver-out, .solver-out .steps, .steps, .steps li { text-align: left; }
/* Hero answer: big serif value, badge in-flow (never clipped/straddling) */
.result .answer, .solver-answer-val {
  font-family: var(--font-display);
  font-size: 2.05rem;
  line-height: 1.25;
  font-weight: 700;
  color: #0B2B4E;
  margin-top: 8px;
  overflow-wrap: anywhere;
  word-break: break-word;
}
.result .verified, .solver-answer .verified {
  position: static;
  margin: 0 0 10px;
}
.ms-answer-label, .solver-answer-label {
  font-size: .78rem;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: #0E7C6B;
  font-weight: 700;
}
/* Result actions row */
.ms-actions { display: flex; gap: 10px; flex-wrap: wrap; margin: 14px 0 2px; }
.ms-actions .btn { min-height: 44px; padding: 10px 18px; font-size: .95rem; }
/* Compact, left-aligned steps: number chip + tighter cards, serif math */
.steps li { padding: 16px 18px 16px 62px; }
.steps .snum {
  left: 14px; top: 15px;
  min-width: 30px; height: 30px; line-height: 30px;
  padding: 0; text-align: center; border-radius: 50%;
  font-size: .85rem;
}
.steps .stitle { text-align: left; }
.steps .smath {
  font-family: var(--font-display);
  font-size: 1.12rem;
  background: #FBF8F0;
  border: 1px solid #EDE6D2;
  color: #1C2430;
  text-align: left;
}
.steps .snote { text-align: left; }
@media (max-width: 560px) {
  .result .answer, .solver-answer-val { font-size: 1.55rem; }
  .steps li { padding: 14px 14px 14px 56px; }
}