/* Modern app-style theme: soft grey canvas, violet → pink accents, Space Grotesk headings, Inter body. Light only. */
[hidden] { display: none !important; }
:root {
  --bg: #f9f9fa; --paper: #ffffff; --ink: #14141f; --muted: #66667a; --line: #e8e8ef; --soft: #f3f1ff;
  --p1: #5b3df5; --p2: #a63cf0; --p3: #ec4899; --ok: #16a34a; --warn: #f59e0b;
  --grad: linear-gradient(90deg, var(--p1), var(--p2) 55%, var(--p3));
  --max: 1200px; --r: 16px;
  --sans: Inter, system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  --display: "Space Grotesk", Inter, system-ui, sans-serif;
  --shadow: 0 1px 2px rgba(20, 20, 31, .04), 0 8px 24px rgba(20, 20, 31, .06);
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body { margin: 0; overflow-x: clip; background: var(--bg); color: var(--ink); font: 16px/1.7 var(--sans); }
a { color: var(--p1); }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 16px; }
.ic { width: 1.1em; height: 1.1em; vertical-align: -.18em; }
.grad { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }

/* header */
.infobar { background: #14141f; color: #c9c9d6; font-size: 13px; }
.infobar .wrap { display: flex; justify-content: space-between; gap: 12px; padding-top: 6px; padding-bottom: 6px; }
.infobar nav { display: flex; gap: 16px; flex-wrap: wrap; }
.infobar a { color: #fff; text-decoration: none; }
.infobar a:hover, .infobar a[aria-current] { text-decoration: underline; }
.top { position: sticky; top: 0; z-index: 20; background: rgba(249, 249, 250, .85); backdrop-filter: saturate(160%) blur(10px); border-bottom: 1px solid var(--line); }
.mainbar { display: flex; align-items: center; justify-content: space-between; gap: 14px; padding-top: 10px; padding-bottom: 10px; flex-wrap: wrap; }
.brand { display: flex; align-items: center; gap: 10px; font: 700 21px/1 var(--display); color: var(--ink); text-decoration: none; margin: 0; letter-spacing: -.01em; }
.brand-mark { display: grid; place-items: center; width: 38px; height: 38px; background: var(--grad); color: #fff; border-radius: 11px; box-shadow: 0 6px 16px rgba(91, 61, 245, .3); }
.brand-mark .ic { width: 22px; height: 22px; }
.mainnav { display: flex; gap: 4px; flex-wrap: wrap; align-items: center; }
.mainnav a { padding: 7px 12px; border-radius: 10px; text-decoration: none; color: var(--ink); font-weight: 600; font-size: 15px; }
.mainnav a:hover, .mainnav a[aria-current] { background: var(--soft); color: var(--p1); }
.chips { display: flex; gap: 6px; flex-wrap: wrap; }
.chip { display: inline-flex; align-items: center; gap: 5px; padding: 5px 11px; border: 1px solid var(--line); border-radius: 999px; background: var(--paper); color: var(--ink); font-size: 13px; font-weight: 600; text-decoration: none; }
.chip:hover { border-color: var(--p1); color: var(--p1); }
.chip .ic { width: 14px; height: 14px; }
.nav-chips { display: flex; }
.cta { display: inline-flex; align-items: center; gap: 6px; background: var(--p1); color: #fff !important; padding: 9px 16px; border-radius: 12px; font-weight: 700; text-decoration: none; font-size: 15px; box-shadow: 0 6px 16px rgba(91, 61, 245, .25); }
.cta:hover { background: #4a2ee0; }
@media (max-width: 980px) { .nav-chips { display: none; } }
@media (max-width: 560px) { .infobar span { display: none; } .infobar .wrap { justify-content: center; } .mainnav .cta { display: none; } }

/* typography */
h1 { font: 700 clamp(32px, 5.4vw, 54px)/1.08 var(--display); margin: 10px 0 12px; letter-spacing: -.02em; }
h2 { font: 700 clamp(22px, 3vw, 28px)/1.25 var(--display); margin: 40px 0 12px; letter-spacing: -.01em; }
h3 { font: 700 19px/1.35 var(--display); margin: 26px 0 8px; }
.lead { font-size: 18px; color: var(--muted); margin: 0 0 18px; max-width: 720px; }
.meta, .updated { color: var(--muted); font-size: 14px; }
.crumbs { font-size: 14px; color: var(--muted); margin: 0; display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.crumbs a { color: var(--muted); text-decoration: none; }
.crumbs a:hover { color: var(--p1); }
table { border-collapse: collapse; width: 100%; margin: 14px 0 18px; font-size: 15px; background: var(--paper); border-radius: 12px; overflow: hidden; }
th, td { border-bottom: 1px solid var(--line); padding: 10px 12px; text-align: left; vertical-align: top; }
th { background: var(--soft); font-weight: 700; color: #3b2fa8; }
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: 12px; margin: 14px 0 18px; }
.table-wrap table { margin: 0; }
.formula { background: #14141f; color: #e6e3ff; border-radius: 12px; padding: 14px 18px; font-family: ui-monospace, Menlo, Consolas, monospace; font-size: 14.5px; overflow-x: auto; }
.note { background: #fff8eb; border: 1px solid #fde3a7; padding: 12px 16px; border-radius: 12px; }

/* page hero (tools, categories, lists) */
.page-hero { background: radial-gradient(1200px 300px at 85% -40%, rgba(236, 72, 153, .12), transparent 60%), radial-gradient(900px 300px at 0% -30%, rgba(91, 61, 245, .14), transparent 60%), #fbfaff; border-bottom: 1px solid var(--line); margin: 0 calc(50% - 50vw) 28px; padding: 26px 16px 30px; }
.page-hero-inner { max-width: var(--max); margin: 0 auto; display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr); gap: 34px; align-items: center; }
.badge { display: inline-flex; align-items: center; gap: 6px; background: var(--soft); color: var(--p1); border: 1px solid #dcd5ff; font-size: 13px; font-weight: 700; padding: 4px 11px; border-radius: 8px; margin: 14px 0 0; }
.hero-actions { display: flex; gap: 10px; flex-wrap: wrap; margin: 4px 0 16px; }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 12px 20px; border-radius: 12px; font-weight: 700; text-decoration: none; font-size: 15px; }
.btn-primary { background: var(--p1); color: #fff; box-shadow: 0 8px 20px rgba(91, 61, 245, .28); }
.btn-primary:hover { background: #4a2ee0; }
.btn-ghost { background: var(--paper); color: var(--ink); border: 1px solid var(--line); }
.btn-ghost:hover { border-color: var(--p1); color: var(--p1); }
.checks { display: flex; gap: 18px; flex-wrap: wrap; color: var(--muted); font-size: 14px; margin: 0; padding: 0; list-style: none; }
.checks li::before { content: "✓"; color: var(--p1); font-weight: 800; margin-right: 6px; }
.hero-art { position: relative; border-radius: 22px; min-height: 230px; background: var(--grad); box-shadow: 0 20px 50px rgba(91, 61, 245, .25); display: grid; place-items: center; overflow: hidden; color: #fff; }
.hero-art::before, .hero-art::after { content: ""; position: absolute; border-radius: 50%; background: rgba(255, 255, 255, .14); }
.hero-art::before { width: 260px; height: 260px; right: -70px; top: -90px; }
.hero-art::after { width: 180px; height: 180px; left: -50px; bottom: -70px; }
.hero-art .ic { width: 96px; height: 96px; stroke-width: 1.6; position: relative; z-index: 1; }
.hero-art .art-tag { position: absolute; left: 18px; bottom: 16px; z-index: 1; font: 600 13px var(--sans); background: rgba(255, 255, 255, .18); padding: 5px 10px; border-radius: 8px; }
@media (max-width: 860px) { .page-hero-inner { grid-template-columns: 1fr; } .hero-art { display: none; } }

/* layout */
.page-grid { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 28px; align-items: start; }
.content { min-width: 0; overflow-wrap: anywhere; }
.content.narrow { max-width: 780px; }
.content.card { background: var(--paper); border: 1px solid var(--line); border-radius: 20px; padding: 6px 26px 22px; box-shadow: var(--shadow); }
.side { position: sticky; top: 80px; display: grid; gap: 16px; }
.side-box { background: var(--paper); border: 1px solid var(--line); border-radius: var(--r); padding: 14px; box-shadow: var(--shadow); }
.side-box h2 { font: 700 12.5px/1.3 var(--sans); text-transform: uppercase; letter-spacing: .07em; color: var(--muted); margin: 2px 4px 10px; display: flex; align-items: center; gap: 6px; }
.side-box ol { margin: 0; padding-left: 22px; font-size: 14.5px; }
.side-box ol li { margin: 4px 0; }
.side-box ol a { color: var(--ink); text-decoration: none; }
.side-box ol a:hover { color: var(--p1); }
.side-tools { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; }
.side-tools a { display: flex; align-items: center; gap: 10px; padding: 8px 10px; border-radius: 12px; text-decoration: none; color: var(--ink); font-size: 14.5px; font-weight: 600; }
.side-tools a:hover, .side-tools a[aria-current] { background: var(--soft); color: var(--p1); }
.side-tools .dot { flex: 0 0 30px; height: 30px; border-radius: 9px; display: grid; place-items: center; background: var(--soft); color: var(--p1); }
.side-tools .dot .ic { width: 16px; height: 16px; }
.side-more { display: block; text-align: center; background: var(--p1); color: #fff; font-weight: 700; font-size: 13px; letter-spacing: .05em; text-transform: uppercase; padding: 10px; border-radius: 12px; text-decoration: none; margin-top: 10px; }
@media (max-width: 960px) { .page-grid { grid-template-columns: 1fr; } .side { position: static; } .toc { display: none; } }

/* calculator card */
.tool { background: var(--paper); border: 1px solid var(--line); border-radius: 20px; padding: 0; box-shadow: var(--shadow); margin: 0 0 26px; scroll-margin-top: 90px; overflow: hidden; }
.tool-head { display: flex; align-items: center; gap: 8px; padding: 14px 20px; border-bottom: 1px solid var(--line); font: 700 15px var(--display); }
.tool-head .ic { color: var(--p1); }
.tool-body { padding: 20px; }
.fields { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 16px; }
.fields label { display: flex; flex-direction: column; gap: 6px; font-weight: 600; font-size: 14.5px; }
.fields .full { grid-column: 1 / -1; }
textarea { resize: vertical; min-height: 96px; }
.fields small { font-weight: 400; color: var(--muted); font-size: 12.5px; }
input, select, textarea { font: inherit; padding: 11px 13px; border: 1px solid #dcdce6; border-radius: 12px; background: #fbfbfd; width: 100%; min-width: 0; color: var(--ink); }
input:focus, select:focus, textarea:focus { outline: 3px solid #e3dcff; border-color: var(--p1); background: #fff; }
.row { display: flex; gap: 8px; }
.calc-btn { margin-top: 18px; width: 100%; font: 700 17px var(--sans); background: var(--p1); color: #fff; border: 0; border-radius: 14px; padding: 15px 22px; cursor: pointer; box-shadow: 0 10px 24px rgba(91, 61, 245, .28); }
.calc-btn:hover { background: #4a2ee0; }
.calc-btn::after { content: "  →"; }
.tool-foot { text-align: center; color: var(--muted); font-size: 13px; margin: 10px 0 0; }
.tool-foot::before { content: "● "; color: var(--ok); }
.result:empty { display: none; }
.result { margin: 18px 20px 20px; background: linear-gradient(180deg, #faf8ff, #fff); border: 1px solid #e4ddff; border-radius: 16px; padding: 18px; }
.result .big { display: block; font: 700 40px/1.1 var(--display); margin: 4px 0 8px; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.result .error { color: #dc2626; font-weight: 600; margin: 0; }
.result details summary { cursor: pointer; font-weight: 700; color: var(--p1); }
.bar { position: relative; height: 14px; border-radius: 99px; background: linear-gradient(90deg, #60a5fa 0 14%, #4ade80 14% 40%, #facc15 40% 60%, #f87171 60%); margin: 10px 0 4px; }
.bar i { position: absolute; top: -5px; width: 4px; height: 24px; background: var(--ink); border-radius: 2px; }
.swap { margin: 12px 0 0; font-weight: 700; font-size: 14.5px; }

/* cards */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 14px; }
.card { display: flex; flex-direction: column; gap: 4px; background: var(--paper); border: 1px solid var(--line); border-radius: var(--r); padding: 16px 18px; text-decoration: none; color: var(--ink); box-shadow: var(--shadow); transition: transform .15s, border-color .15s; }
.card:hover { transform: translateY(-2px); border-color: #cfc5ff; }
.card b { font: 700 17px/1.3 var(--display); }
.card span { color: var(--muted); font-size: 14px; line-height: 1.5; }
.card .card-cat { font-size: 11.5px; text-transform: uppercase; letter-spacing: .07em; color: var(--p1); font-weight: 700; }
.block { margin: 46px 0; }
.block-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; }
.block h2 { margin: 0 0 14px; }
.block h2 a { color: var(--ink); text-decoration: none; }
.more { font-weight: 700; text-decoration: none; white-space: nowrap; }
.section-tag { display: inline-flex; gap: 6px; align-items: center; background: #fdf2f8; color: var(--p3); border: 1px solid #fbcfe8; border-radius: 999px; padding: 4px 12px; font-size: 13px; font-weight: 700; }
.center { text-align: center; }
.center .lead { margin-left: auto; margin-right: auto; }
.pager { display: grid; grid-template-columns: 1fr auto 1fr; gap: 12px; margin: 34px 0; }
.pager a { display: flex; flex-direction: column; background: var(--paper); border: 1px solid var(--line); border-radius: var(--r); padding: 14px 16px; text-decoration: none; color: var(--ink); box-shadow: var(--shadow); }
.pager a:hover { border-color: var(--p1); }
.pager a:last-child { text-align: right; }
.pager a:nth-child(2) { text-align: center; }
.pager small { color: var(--muted); font-size: 12.5px; text-transform: uppercase; letter-spacing: .05em; }
@media (max-width: 560px) { .pager { grid-template-columns: 1fr 1fr; } .pager a:nth-child(2) { display: none; } }
.faq details { background: var(--paper); border: 1px solid var(--line); border-radius: 14px; padding: 12px 16px; margin: 8px 0; }
.faq summary { font-weight: 700; cursor: pointer; }
.sources { font-size: 14.5px; color: var(--muted); }

/* home */
.home-hero { margin: 0 calc(50% - 50vw); padding: 46px 16px 54px; background: radial-gradient(900px 380px at 100% 0%, rgba(236, 72, 153, .10), transparent 60%), radial-gradient(900px 380px at 0% 0%, rgba(91, 61, 245, .12), transparent 60%); }
.home-hero .page-hero-inner { grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr); }
.eyebrow { display: flex; align-items: center; gap: 10px; color: var(--p1); font-weight: 700; font-size: 13px; letter-spacing: .12em; text-transform: uppercase; }
.eyebrow::before { content: ""; width: 30px; height: 2px; background: var(--p1); }
.home-hero h1 { font-size: clamp(36px, 6vw, 60px); }
.stats { display: flex; gap: 26px; margin: 22px 0 0; flex-wrap: wrap; }
.stats div { border-left: 2px solid var(--line); padding-left: 14px; }
.stats div:first-child { border-left: 0; padding-left: 0; }
.stats b { display: block; font: 700 28px/1.1 var(--display); }
.stats span { color: var(--muted); font-size: 13px; }
.search-card { background: var(--paper); border: 1px solid var(--line); border-radius: 22px; padding: 22px; box-shadow: 0 24px 60px rgba(20, 20, 31, .10); }
.search-card h2 { margin: 0 0 2px; font-size: 20px; }
.search-card p { margin: 0 0 14px; color: var(--muted); font-size: 14px; }
.search-card input { font-size: 16px; padding: 13px 16px; border-radius: 14px; }
.search-card .chips { margin-top: 12px; }
.search-card .label { font-size: 12.5px; color: var(--muted); font-weight: 600; margin: 14px 0 6px; }
.q-results { display: grid; gap: 6px; margin-top: 8px; }
.q-results a { background: var(--soft); border-radius: 10px; padding: 8px 12px; text-decoration: none; color: var(--ink); font-weight: 600; font-size: 14.5px; }
.q-results small { color: var(--muted); margin-left: 6px; font-weight: 400; }
.cat-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 16px; margin-top: 24px; }
.cat-card { position: relative; display: flex; flex-direction: column; gap: 6px; min-height: 170px; padding: 20px; border-radius: 20px; text-decoration: none; color: var(--ink); border: 1px solid var(--line); background: var(--paper); box-shadow: var(--shadow); overflow: hidden; transition: transform .15s; }
.cat-card:hover { transform: translateY(-3px); }
.cat-card .cat-ic { width: 46px; height: 46px; border-radius: 14px; display: grid; place-items: center; color: #fff; margin-bottom: 8px; }
.cat-card .cat-ic .ic { width: 24px; height: 24px; }
.cat-card b { font: 700 19px var(--display); }
.cat-card span { color: var(--muted); font-size: 14px; line-height: 1.5; }
.cat-card .count { position: absolute; top: 16px; right: 16px; font-size: 12px; font-weight: 700; color: var(--p1); background: var(--soft); border-radius: 999px; padding: 3px 10px; }
.cat-card::after { content: ""; position: absolute; right: -40px; bottom: -50px; width: 140px; height: 140px; border-radius: 50%; opacity: .12; background: currentColor; }
.lists { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
@media (max-width: 860px) { .lists { grid-template-columns: 1fr; } }
.list-head { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; }
.list-head .ring { width: 38px; height: 38px; border-radius: 50%; display: grid; place-items: center; color: #fff; background: var(--grad); }
.list-head b { font: 700 19px var(--display); display: block; }
.list-head small { color: var(--muted); }
.ranked { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.ranked a { display: flex; align-items: center; gap: 14px; background: var(--paper); border: 1px solid var(--line); border-radius: 14px; padding: 12px 14px; text-decoration: none; color: var(--ink); box-shadow: var(--shadow); }
.ranked a:hover { border-color: var(--p1); }
.ranked .n { flex: 0 0 30px; height: 30px; border-radius: 50%; display: grid; place-items: center; background: var(--soft); color: var(--p1); font-weight: 800; font-size: 14px; }
.ranked b { display: block; font-size: 15px; }
.ranked small { color: var(--muted); font-size: 13px; display: block; line-height: 1.4; }
.about-strip { background: var(--paper); border: 1px solid var(--line); border-radius: 20px; padding: 24px 26px; box-shadow: var(--shadow); }

/* A–Z */
.az-jump { display: flex; flex-wrap: wrap; gap: 6px; }
.az-jump a { display: grid; place-items: center; width: 38px; height: 38px; background: var(--paper); border: 1px solid var(--line); border-radius: 10px; text-decoration: none; font-weight: 700; }
.az-jump a:hover { border-color: var(--p1); }
.az ul { columns: 3 240px; padding-left: 18px; }
.az li { margin: 3px 0; break-inside: avoid; }
.az small { color: var(--muted); }

/* footer */
.foot { background: #14141f; color: #b9b9c8; margin-top: 60px; padding: 36px 0 16px; font-size: 14.5px; }
.foot-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 28px; }
.foot h2 { font: 700 13px var(--sans); text-transform: uppercase; letter-spacing: .08em; color: #fff; margin: 0 0 10px; }
.foot nav a { display: block; color: #e2e2ea; text-decoration: none; padding: 3px 0; }
.foot nav a:hover { color: #fff; text-decoration: underline; }
.foot-brand { color: #fff; }
.copy { font-size: 13px; margin-top: 24px; color: #8c8ca0; }
.copy a { color: #c9c9d6; }
@media (max-width: 720px) { .foot-grid { grid-template-columns: 1fr 1fr; } .foot-grid > div:first-child { grid-column: 1 / -1; } }

/* illustrations */
.hero-illus { border-radius: 22px; overflow: hidden; background: linear-gradient(135deg, #f3f0ff, #fdf2f8); border: 1px solid var(--line); box-shadow: 0 20px 50px rgba(91, 61, 245, .14); aspect-ratio: 16 / 10; position: relative; }
.hero-illus img { position: absolute; top: 9%; left: 8%; width: 84%; height: 82%; object-fit: contain; }
@media (max-width: 860px) { .hero-illus { display: none; } }
.cat-card { padding: 0 0 18px; }
.cat-card .cat-img { display: block; position: relative; width: 100%; aspect-ratio: 16 / 9; background: linear-gradient(135deg, #f5f3ff, #fdf2f8); border-bottom: 1px solid var(--line); margin-bottom: 4px; }
.cat-card .cat-img img { position: absolute; top: 10%; left: 10%; width: 80%; height: 80%; object-fit: contain; }
.cat-card .cat-ic, .cat-card b, .cat-card > span:not(.count):not(.cat-img) { margin-left: 20px; margin-right: 20px; }
.cat-card .cat-ic { margin-top: -30px; position: relative; z-index: 1; border: 3px solid #fff; }
.cat-card .count { z-index: 1; background: #fff; }
.cat-card::after { display: none; }
.hero-photo { border-radius: 22px; overflow: hidden; aspect-ratio: 16 / 10; box-shadow: 0 24px 60px rgba(20, 20, 31, .18); position: relative; }
.hero-photo img { width: 100%; height: 100%; object-fit: cover; display: block; }
.hero-photo::after { content: ""; position: absolute; inset: 0; background: linear-gradient(160deg, rgba(91, 61, 245, .10), rgba(236, 72, 153, .10)); }
@media (max-width: 860px) { .hero-photo { display: none; } }
.cat-card .cat-img.is-photo img { top: 0; left: 0; width: 100%; height: 100%; object-fit: cover; }