/* Professional palette: deep navy for trust, the WK logo's gold used sparingly as an accent */
:root{
  --bg:#f6f8fb; --card:#ffffff; --ink:#14233a; --muted:#56657a; --line:#e2e8f0;
  --brand:#0b2545;          /* headings, primary buttons, outline buttons (navy) */
  --accent:#1f5aa6;         /* links, active menu item (blue) */
  --gold:#b08d3c;           /* decorative gold: logo word, underlines, borders */
  --gold-ink:#86682a;       /* gold text on light backgrounds (eyebrows, tagline) */
  --accent2:#b42318;        /* errors, wrong answers */
  --ok:#1e7b4f;             /* correct answers */
  --btn-bg:#0b2545; --btn-ink:#ffffff; --btn-hover:#163a69;
  --result:#0b2545; --result-num:#e3c47e; --footer:#0a1b31;
  --shadow:0 1px 2px rgba(11,37,69,.06),0 8px 24px -12px rgba(11,37,69,.18);
}
@media (prefers-color-scheme:dark){
  :root{--bg:#0b1322; --card:#111c2f; --ink:#e4e9f0; --muted:#9aa7ba; --line:#22314a;
    --brand:#f1f4f8; --accent:#8db8ec; --gold:#c8a55a; --gold-ink:#d2b36d; --accent2:#f08b7d; --ok:#6fcf97;
    --btn-bg:#c8a55a; --btn-ink:#0b1322; --btn-hover:#d6b672;
    --result:#16243b; --result-num:#e3c47e; --footer:#070e1a; --shadow:0 10px 30px -14px rgba(0,0,0,.6)}
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font:400 17px/1.65 Inter,"Noto Sans Telugu",system-ui,sans-serif}
h1,h2,h3{font-family:Fraunces,Georgia,serif;line-height:1.15;margin:0 0 .5em;color:var(--brand)}
h1{font-size:clamp(2.4rem,6vw,4.2rem);font-weight:700;letter-spacing:-.01em}
h2{font-size:clamp(1.8rem,4vw,2.6rem);font-weight:700;letter-spacing:-.005em}
h3{font-size:1.3rem;font-weight:600}
a{color:var(--accent)}
.wrap{max-width:1120px;margin:0 auto;padding:0 20px}
section{padding:72px 0}
.eyebrow{font-weight:600;letter-spacing:.14em;text-transform:uppercase;font-size:.78rem;color:var(--gold-ink)}
.te{font-family:"Noto Sans Telugu",Inter,sans-serif;color:var(--muted)}
.lead{font-size:1.2rem;max-width:640px;color:var(--muted)}

/* nav */
header{position:sticky;top:0;z-index:10;background:color-mix(in srgb,var(--bg) 90%,transparent);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
nav{display:flex;align-items:center;justify-content:space-between;height:64px;position:relative}
.logo{font-family:Fraunces,serif;font-weight:700;font-size:1.3rem;color:var(--brand);text-decoration:none}
.logo .k{color:var(--gold)}
.logo{display:flex;align-items:center;gap:10px}
.logo img{width:38px;height:38px;border-radius:9px;display:block}
nav ul{display:flex;align-items:center;gap:22px;list-style:none;margin:0;padding:0}
nav ul a{text-decoration:none;color:var(--ink);font-weight:500;font-size:.95rem}
nav ul a:hover,nav ul a[aria-current]{color:var(--accent)}
nav ul a[aria-current]{text-decoration:underline;text-underline-offset:6px;text-decoration-color:var(--gold);text-decoration-thickness:2px}
.menu{display:none;background:none;border:1px solid var(--line);border-radius:10px;font-size:1.3rem;padding:4px 12px;color:var(--ink);cursor:pointer}
@media(max-width:860px){
  .menu{display:block}
  nav ul{display:none;position:absolute;top:64px;left:-20px;right:-20px;flex-direction:column;align-items:flex-start;gap:0;background:var(--bg);border-bottom:1px solid var(--line);padding:8px 20px 16px}
  nav ul li{width:100%}
  nav ul a{display:block;padding:10px 0}
  header.open nav ul{display:flex}
}
.btn{display:inline-block;background:var(--btn-bg);color:var(--btn-ink);padding:12px 24px;border-radius:999px;font-weight:600;text-decoration:none;border:0;cursor:pointer;font-size:1rem}
.btn:hover{background:var(--btn-hover)}
.btn.alt{background:transparent;color:var(--brand);border:2px solid var(--brand)}
.btn.alt:hover{background:color-mix(in srgb,var(--brand) 8%,transparent)}
nav ul a.btn,nav ul a.btn:hover{color:var(--btn-ink);padding:8px 18px}
@media(max-width:860px){nav ul a.btn{display:inline-block;margin-top:8px}}

/* hero */
.hero{padding:88px 0 72px;background:
  radial-gradient(900px 420px at 85% -10%,rgba(31,90,166,.10),transparent 60%),
  radial-gradient(700px 400px at -10% 110%,rgba(176,141,60,.07),transparent 60%)}
.hero.small{padding:56px 0 40px}
.hero-grid{display:grid;grid-template-columns:1fr 340px;gap:48px;align-items:center}
.hero-grid>div{grid-row:1;grid-column:1}
.hero-logo{grid-row:1;grid-column:2;width:100%;height:auto;border-radius:28px;box-shadow:0 30px 60px -25px rgba(0,0,0,.55),0 0 0 1px color-mix(in srgb,var(--gold) 40%,transparent)}
@media(max-width:860px){
  .hero-grid{grid-template-columns:1fr;gap:28px}
  .hero-logo{grid-column:1;width:120px;border-radius:20px}
  .hero-grid>div{grid-row:2}
}
.hero .cta{display:flex;gap:14px;flex-wrap:wrap;margin-top:28px}
.tagline{margin-top:36px;font-family:Fraunces,serif;font-style:italic;font-size:1.3rem;color:var(--gold-ink)}

/* cards */
.grid{display:grid;gap:20px;grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}
.card{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:26px;box-shadow:var(--shadow)}
.card .ico{font-size:1.8rem}
.card p{margin:.3em 0 0;color:var(--muted);font-size:.97rem}
a.card{text-decoration:none;color:inherit;transition:transform .15s,border-color .15s}
a.card:hover{transform:translateY(-3px);border-color:var(--gold)}
.card .go{display:inline-block;margin-top:12px;font-weight:600;color:var(--accent);font-size:.92rem}

/* tool chips */
.chips{display:flex;gap:10px;flex-wrap:wrap;margin-top:20px}
.chips a{background:var(--card);border:1px solid var(--line);border-radius:999px;padding:7px 16px;text-decoration:none;color:var(--ink);font-size:.9rem;font-weight:500}
.chips a:hover{border-color:var(--gold);color:var(--accent)}

/* tools */
.tools{padding-top:24px}
.tool{background:var(--card);border:1px solid var(--line);border-radius:22px;padding:30px;box-shadow:var(--shadow);margin-bottom:32px;scroll-margin-top:84px}
.tool h2{font-size:clamp(1.5rem,3vw,2rem);margin-bottom:.25em}
.tool .desc{color:var(--muted);margin:0 0 18px;max-width:760px}
.stamp{display:inline-block;font-size:.8rem;font-weight:600;color:var(--ok);background:color-mix(in srgb,var(--ok) 9%,var(--card));border:1px solid color-mix(in srgb,var(--ok) 28%,transparent);padding:3px 12px;border-radius:99px;margin:-6px 0 16px}
@media(max-width:600px){.tool{padding:20px}}
.calc{display:grid;gap:28px;grid-template-columns:1.1fr 1fr;align-items:start}
@media(max-width:860px){.calc{grid-template-columns:1fr}}
.fields{display:grid;gap:12px 16px;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));align-content:start}
.fields .full{grid-column:1/-1}
.fields label{display:block;font-weight:600;font-size:.84rem;margin:0 0 4px;color:var(--ink)}
.fields label small{font-weight:400;color:var(--muted)}
input,select{width:100%;padding:9px 11px;border:1px solid var(--line);border-radius:10px;background:var(--bg);color:var(--ink);font:inherit;font-size:.97rem}
input:focus,select:focus{outline:2px solid var(--gold);outline-offset:1px}
input[type=checkbox],input[type=radio]{width:auto;flex:none;accent-color:var(--accent)}
.check{display:flex;gap:8px;align-items:center;font-weight:600;font-size:.88rem}
.subhead{grid-column:1/-1;font-family:Fraunces,serif;font-weight:600;color:var(--brand);margin-top:8px;border-top:1px dashed var(--line);padding-top:12px}
details.rates{grid-column:1/-1;border:1px dashed var(--line);border-radius:12px;padding:10px 14px}
details.rates summary{cursor:pointer;font-weight:600;font-size:.88rem;color:var(--accent)}
details.rates .fields{margin-top:12px}
.lots{grid-column:1/-1;display:grid;gap:8px}
.lot{display:grid;grid-template-columns:1fr 1fr 36px;gap:8px;align-items:center}
.lot button,.addlot{background:none;border:1px solid var(--line);border-radius:10px;color:var(--ink);cursor:pointer;font:inherit;padding:8px}
.addlot{grid-column:1/-1;justify-self:start;padding:8px 16px;font-weight:600;color:var(--accent)}

.result{background:var(--result);border:1px solid color-mix(in srgb,var(--gold) 35%,transparent);color:#fff;border-radius:18px;padding:26px;position:sticky;top:84px}
@media(max-width:860px){.result{position:static}}
.result .rlabel{opacity:.85}
.result .big{font-family:Fraunces,serif;font-size:clamp(1.9rem,4.5vw,2.7rem);font-weight:800;color:var(--result-num);line-height:1.15;word-break:break-word}
.result dl{margin:18px 0 0;display:grid;grid-template-columns:auto 1fr;gap:7px 16px}
.result dt{opacity:.82}.result dd{margin:0;text-align:right;font-weight:600;font-variant-numeric:tabular-nums}
.result dt.sep,.result dd.sep{border-top:1px solid rgba(255,255,255,.25);padding-top:7px}
.result table{min-width:0;width:100%;margin-top:14px;font-variant-numeric:tabular-nums}
.result th,.result td{color:#fff;border-bottom:1px solid rgba(255,255,255,.18);padding:7px 8px;font-size:.88rem;text-align:right}
.result th:first-child,.result td:first-child{text-align:left}
.result th{background:rgba(255,255,255,.1);font-family:Inter,sans-serif}
.result details{margin-top:16px}
.result summary{cursor:pointer;font-weight:600;color:var(--gold)}
.result .scroll{max-height:320px;overflow:auto}
.result .warn{margin-top:14px;background:rgba(232,163,23,.18);border-left:3px solid var(--gold);padding:8px 12px;border-radius:6px;font-size:.9rem}
.result .err{color:#ffd2c2;font-weight:600}
.pos{color:#9ef0b8}.neg{color:#ffb4a0}
.bar{height:14px;border-radius:99px;background:rgba(255,255,255,.2);overflow:hidden;margin-top:18px;display:flex}
.bar i{display:block;height:100%}
.note{font-size:.84rem;color:var(--muted);margin-top:12px}
.result .note{color:rgba(255,255,255,.72)}

/* tables */
.tablewrap{overflow-x:auto;border:1px solid var(--line);border-radius:18px;background:var(--card)}
table{border-collapse:collapse;width:100%}
.tablewrap table{min-width:560px}
th,td{padding:14px 18px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top;font-size:.96rem}
.tablewrap th{background:color-mix(in srgb,var(--brand) 7%,var(--card));font-family:Fraunces,serif}
tr:last-child td{border-bottom:0}

/* about + footer */
.about{display:grid;gap:32px;grid-template-columns:1.3fr 1fr;align-items:center}
@media(max-width:800px){.about{grid-template-columns:1fr}}
.badge-list{list-style:none;padding:0;margin:0;display:grid;gap:10px}
.badge-list li{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:12px 16px;font-weight:500}
.host-photo{display:flex;align-items:center;gap:18px;margin:0 0 18px}
.host-photo img{width:132px;height:132px;border-radius:50%;object-fit:cover;flex:none;border:3px solid var(--card);box-shadow:0 0 0 2px var(--gold),var(--shadow)}
.host-photo figcaption{display:flex;flex-direction:column;gap:2px}
.host-photo strong{font-family:Fraunces,Georgia,serif;font-size:1.45rem;color:var(--brand);line-height:1.2}
.host-photo span{color:var(--muted);font-size:.95rem}
footer{background:var(--footer);color:#e6dfcf;border-top:2px solid var(--gold);padding:48px 0 32px}
footer a{color:var(--gold)}
footer .closing{font-family:Fraunces,serif;font-size:1.5rem;font-style:italic;color:#fff}
footer .flinks{display:flex;gap:20px;flex-wrap:wrap;margin-top:14px}
.disclaimer{font-size:.8rem;opacity:.8;margin-top:24px;border-top:1px solid rgba(255,255,255,.2);padding-top:18px}

/* ---------- Education ---------- */
.filters{display:grid;gap:12px;grid-template-columns:2fr repeat(4,1fr);margin-bottom:24px}
@media(max-width:860px){.filters{grid-template-columns:1fr 1fr}.filters input[type=search]{grid-column:1/-1}}
.count{color:var(--muted);font-size:.9rem;margin:-8px 0 18px}
.libcard{display:flex;flex-direction:column}
.libcard h3{margin:10px 0 6px}
.libcard .meta{font-size:.82rem;color:var(--muted);margin-top:10px}
.libcard .actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:auto;padding-top:16px}
.libcard .btn{padding:8px 18px;font-size:.92rem}
.libcard .btn.alt{padding:6px 16px}
.badge{display:inline-block;font-size:.72rem;font-weight:600;letter-spacing:.06em;text-transform:uppercase;padding:3px 10px;border-radius:99px;background:color-mix(in srgb,var(--gold) 25%,var(--card));color:var(--ink)}
.badge.test{background:color-mix(in srgb,var(--accent) 22%,var(--card))}
.badge.book{background:color-mix(in srgb,var(--accent2) 18%,var(--card))}
.badge.best{background:var(--btn-bg);color:var(--btn-ink);margin-left:6px}
.empty{text-align:center;color:var(--muted);padding:40px 0}

/* reader */
.reader{max-width:780px;margin:0 auto}
.reader .back{display:inline-block;margin-bottom:18px;text-decoration:none;font-weight:600}
.prose{background:var(--card);border:1px solid var(--line);border-radius:22px;padding:40px;box-shadow:var(--shadow)}
@media(max-width:600px){.prose{padding:22px}}
.prose h1{font-size:clamp(1.9rem,4.5vw,2.6rem)}
.prose h2{font-size:1.5rem;margin-top:1.6em}
.prose h3{margin-top:1.3em}
.prose table{margin:1em 0;display:block;overflow-x:auto}
.prose th{background:color-mix(in srgb,var(--brand) 7%,var(--card))}
.prose th,.prose td{padding:9px 12px;border:1px solid var(--line)}
.prose blockquote{margin:1em 0;padding:10px 18px;border-left:4px solid var(--gold);background:color-mix(in srgb,var(--gold) 10%,var(--card));border-radius:0 10px 10px 0}
.prose code{background:color-mix(in srgb,var(--line) 60%,transparent);padding:1px 6px;border-radius:6px;font-size:.92em}
.prose img{max-width:100%;border-radius:12px}
.reader .docmeta{color:var(--muted);font-size:.9rem;margin-bottom:12px}
.reader .nextup{margin-top:24px;display:flex;gap:12px;flex-wrap:wrap}

/* quiz */
.quiz{background:var(--card);border:1px solid var(--line);border-radius:22px;padding:34px;box-shadow:var(--shadow)}
@media(max-width:600px){.quiz{padding:20px}}
.qtop{display:flex;justify-content:space-between;gap:12px;font-weight:600;font-size:.92rem;color:var(--muted)}
.qtimer.low{color:var(--accent2)}
.progress{height:8px;background:var(--line);border-radius:99px;overflow:hidden;margin:10px 0 24px}
.progress i{display:block;height:100%;background:var(--accent);transition:width .2s}
.qtext{font-family:Fraunces,serif;font-size:1.3rem;font-weight:600;line-height:1.35;margin-bottom:18px}
.opts{display:grid;gap:10px}
.opt{display:flex;gap:12px;align-items:flex-start;padding:13px 16px;border:2px solid var(--line);border-radius:14px;cursor:pointer;background:var(--bg)}
.opt:hover{border-color:var(--gold)}
.opt input{margin-top:5px}
.opt.sel{border-color:var(--accent);background:color-mix(in srgb,var(--accent) 10%,var(--bg))}
.opt.right{border-color:var(--ok);background:color-mix(in srgb,var(--ok) 14%,var(--bg))}
.opt.wrong{border-color:var(--accent2);background:color-mix(in srgb,var(--accent2) 12%,var(--bg))}
.qnav{display:flex;justify-content:space-between;gap:10px;margin-top:24px;flex-wrap:wrap}
.palette{display:flex;gap:6px;flex-wrap:wrap;margin-top:22px}
.palette button{width:34px;height:34px;border-radius:9px;border:1px solid var(--line);background:var(--bg);color:var(--ink);cursor:pointer;font:600 .85rem Inter,sans-serif}
.palette button.done{background:var(--btn-bg);color:var(--btn-ink);border-color:var(--btn-bg)}
.palette button.cur{outline:2px solid var(--gold)}
.score{text-align:center;padding:10px 0 24px}
.score .big{font-family:Fraunces,serif;font-size:3.4rem;font-weight:800;color:var(--brand);line-height:1}
.score .verdict{font-weight:700;font-size:1.1rem;margin-top:8px}
.verdict.pass{color:var(--ok)}.verdict.fail{color:var(--accent2)}
.review{margin-top:22px;border-top:1px dashed var(--line);padding-top:18px}
.review .item{margin-bottom:26px}
.explain{margin-top:10px;font-size:.93rem;color:var(--muted);background:color-mix(in srgb,var(--gold) 9%,var(--bg));padding:10px 14px;border-radius:10px}

@media print{
  header,footer,.reader .back,.reader .nextup,.noprint{display:none!important}
  body{background:#fff;color:#000}
  .prose{border:0;box-shadow:none;padding:0}
}

/* ---------- Share / save bar on each calculator ---------- */
.tool-actions{display:flex;flex-wrap:wrap;align-items:center;gap:10px;margin-top:22px;padding-top:18px;border-top:1px dashed var(--line)}
.tool-actions .act{font:600 .9rem Inter,sans-serif;padding:9px 16px;border-radius:999px;cursor:pointer;border:1.5px solid var(--line);background:var(--card);color:var(--ink)}
.tool-actions .act:hover{border-color:var(--brand)}
.tool-actions .act.wa{background:#1f8f4e;border-color:#1f8f4e;color:#fff}
.tool-actions .act.wa:hover{background:#18763f}
.tool-actions .act-msg{font-size:.8rem;color:var(--muted)}
.print-head,.print-foot{display:none}

/* ---------- Print one calculator ("Save as PDF") ---------- */
@media print{
  body.printing-one{--bg:#fff;--card:#fff;--ink:#14233a;--muted:#56657a;--line:#d5dbe3;--brand:#0b2545;--accent:#1f5aa6;--gold:#b08d3c;--gold-ink:#86682a;--ok:#1e7b4f}
  body.printing-one main>section:not(.tools),body.printing-one .tool:not(.print-target){display:none!important}
  body.printing-one .tools{padding:0}
  body.printing-one .tool.print-target{box-shadow:none;border:0;padding:0;margin:0}
  body.printing-one .print-head{display:flex!important;justify-content:space-between;border-bottom:2px solid #0b2545;padding-bottom:8px;margin-bottom:18px;color:#0b2545;font-size:11pt}
  body.printing-one .print-foot{display:block!important;margin-top:20px;border-top:1px solid #d5dbe3;padding-top:8px;font-size:8.5pt;color:#56657a;word-break:break-all}
  body.printing-one .calc{grid-template-columns:1fr 1fr;gap:20px}
  body.printing-one input,body.printing-one select{border:0;background:none;padding:0;font-weight:700;color:#14233a}
  body.printing-one .lot button,body.printing-one .addlot,body.printing-one details.rates summary{display:none}
  body.printing-one .result{position:static;background:#fff;border:1.5px solid #0b2545;color:#14233a;break-inside:avoid}
  body.printing-one .result *{color:#14233a}
  body.printing-one .result .big{color:#0b2545}
  body.printing-one .result .note{color:#56657a}
  body.printing-one .bar{background:#e6ebf2;-webkit-print-color-adjust:exact;print-color-adjust:exact}
  body.printing-one .bar i:first-child{background:#9fb0c6!important}
  body.printing-one .bar i:last-child{background:#b08d3c!important}
  body.printing-one .stamp{-webkit-print-color-adjust:exact;print-color-adjust:exact}
}

/* ---------- Legal pages ---------- */
.prose.legal h2{font-size:1.25rem;margin-top:1.8em}
.prose.legal li{margin-bottom:.45em}
mark.todo{background:#fff1a8;color:#4d3b00;padding:1px 5px;border-radius:4px}
footer .flegal{margin-top:6px;font-size:.88rem}