/* INTRVL guides — short, answer-first pages. Paper and ink, same as the home page. */
:root{
  --paper:#F2F0EB; --paper2:#E9E6DF; --ink:#141414; --ink2:#55534E; --ink3:#8A877F;
  --rule:#D6D2C9; --rule2:#C2BDB2; --blue:#2F5BFF;
  --sans:"Geist",-apple-system,"Segoe UI",Helvetica,Arial,sans-serif;
  --mono:"Geist Mono",ui-monospace,"SF Mono",Menlo,Consolas,monospace;
  --pad:clamp(16px,4vw,48px);
  color-scheme:light;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--sans);font-size:17px;line-height:1.6;-webkit-font-smoothing:antialiased;overflow-x:hidden}
a{color:inherit}
::selection{background:var(--ink);color:var(--paper)}
:focus-visible{outline:2px solid var(--ink);outline-offset:3px}
.wrap{max-width:1180px;margin:0 auto;padding-inline:var(--pad)}
.small{font-family:var(--mono);font-size:11.5px;letter-spacing:.06em;text-transform:uppercase;color:var(--ink3)}

header.top{border-bottom:1px solid var(--rule)}
header.top .wrap{display:flex;align-items:center;justify-content:space-between;height:56px;gap:16px}
.mark{display:inline-flex;align-items:baseline;gap:.62em;font-weight:600;letter-spacing:.14em;font-size:17px;line-height:1;text-decoration:none}
.mark i{display:inline-flex;gap:.30em}.mark i::before,.mark i::after{content:"";width:.13em;height:.71em;background:currentColor}
header.top nav{display:flex;gap:20px;font-size:14px}
header.top nav a{color:var(--ink2);text-decoration:none}
header.top nav a:hover,header.top nav a[aria-current]{color:var(--ink)}

/* index */
.gi{padding:clamp(32px,6vw,72px) 0 24px}
.gi h1{margin:6px 0 0;font-weight:500;font-size:clamp(40px,6.4vw,84px);letter-spacing:-.045em;line-height:.95}
.gi p{margin:16px 0 0;color:var(--ink2);max-width:56ch}
.gi .crumb{font-family:var(--mono);font-size:12px;color:var(--ink3)}
.gi .crumb a{color:var(--ink3)}
.vh{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%)}
[hidden]{display:none!important}

/* finder: search + topic chips */
.finder{display:grid;gap:14px;margin:8px 0 32px;position:sticky;top:0;z-index:5;background:var(--paper);padding:12px 0;border-bottom:1px solid var(--rule)}
.search{position:relative;display:block}
.search input{width:100%;font:inherit;font-size:17px;padding:13px 44px 13px 16px;border:1px solid var(--rule2);border-radius:12px;background:#fff;color:var(--ink);-webkit-appearance:none}
.search input:focus{outline:none;border-color:var(--ink)}
.search kbd{position:absolute;right:12px;top:50%;transform:translateY(-50%);font-family:var(--mono);font-size:11px;border:1px solid var(--rule2);border-radius:5px;padding:1px 6px;color:var(--ink3)}
@media (hover:none){.search kbd{display:none}}
.chips{display:flex;gap:6px;flex-wrap:wrap}
.chip{font:inherit;font-size:14px;border:1px solid var(--rule2);background:transparent;color:var(--ink);border-radius:999px;padding:6px 12px;cursor:pointer}
.chip i{font-style:normal;font-family:var(--mono);font-size:11px;color:var(--ink3);margin-left:4px}
.chip[aria-pressed="true"]{background:var(--ink);border-color:var(--ink);color:var(--paper)}
.chip[aria-pressed="true"] i{color:#a9a79f}

/* start here */
.feat{margin:0 0 48px}
.feat .cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;margin-top:12px}
@media (max-width:900px){.feat .cards{grid-template-columns:minmax(0,1fr)}}
.card{display:flex;flex-direction:column;gap:8px;padding:20px;border-radius:16px;background:#fff;border:1px solid var(--rule);text-decoration:none;transition:transform .25s,box-shadow .25s}
.card:hover{transform:translateY(-2px);box-shadow:0 14px 30px -20px #0005}
.card .tag{font-family:var(--mono);font-size:11.5px;color:var(--ink3)}
.card h2{margin:0;font-size:clamp(20px,2vw,24px);font-weight:500;letter-spacing:-.02em;line-height:1.2}
.card p{margin:0;color:var(--ink2);font-size:15px;line-height:1.5;flex:1}
.card .when{font-family:var(--mono);font-size:12px;color:var(--ink)}

/* grouped list */
.group{margin:0 0 48px}
.ghead{display:flex;align-items:baseline;justify-content:space-between;gap:12px;border-bottom:1px solid var(--ink);padding-bottom:10px}
.ghead h2{margin:0;font-size:clamp(24px,2.6vw,32px);font-weight:500;letter-spacing:-.03em}
.ghead a{text-decoration:none}
.ghead .small a{color:var(--ink3);text-decoration:underline}
.glist{list-style:none;margin:0 0 48px;padding:0}
.group .glist{margin:0}
main > .glist{border-top:1px solid var(--ink)}
.glist a{display:grid;grid-template-columns:120px minmax(0,1fr) auto;gap:24px;align-items:baseline;padding:20px 0;border-bottom:1px solid var(--rule);text-decoration:none}
.glist .tag{font-family:var(--mono);font-size:12px;color:var(--ink3)}
.glist h3{margin:0;font-size:clamp(19px,2vw,24px);font-weight:500;letter-spacing:-.02em;line-height:1.25}
.glist p{margin:6px 0 0;color:var(--ink2);font-size:15.5px}
.glist .when{display:block;margin-top:8px;font-family:var(--mono);font-size:11.5px;color:var(--ink3)}
.glist .go{font-size:20px;transition:transform .2s}
.glist a:hover .go{transform:translateX(4px)}
.glist a:hover h3{text-decoration:underline;text-underline-offset:3px}
@media (max-width:640px){.glist a{grid-template-columns:minmax(0,1fr) auto}.glist .tag{grid-column:1/-1}}
.none{color:var(--ink2);margin:0 0 72px}
main.wrap > .cta{margin:0 0 72px}

/* article */
article{max-width:720px;margin:0 auto;padding:clamp(32px,6vw,72px) var(--pad) 40px}
article .crumb{font-family:var(--mono);font-size:12px;color:var(--ink3)}
article .crumb a{color:var(--ink3)}
article h1{margin:12px 0 0;font-weight:500;font-size:clamp(34px,5vw,54px);letter-spacing:-.04em;line-height:1.02}
.answer{margin:24px 0 0;padding:18px 20px;background:#fff;border:1px solid var(--rule);border-left:3px solid var(--ink);border-radius:10px;font-size:18px;line-height:1.55}
.answer strong{font-weight:600}
article h2{margin:40px 0 0;font-weight:500;font-size:clamp(22px,2.6vw,28px);letter-spacing:-.02em;line-height:1.2}
article p,article li{color:#2b2a27}
article p{margin:14px 0 0}
article ol,article ul{margin:14px 0 0;padding-left:1.3em}
article li{margin:8px 0 0;padding-left:.2em}
article li::marker{font-family:var(--mono);font-size:.85em;color:var(--ink3)}
article code{font-family:var(--mono);font-size:.86em;background:var(--paper2);border-radius:5px;padding:2px 6px;overflow-wrap:anywhere}
article pre{margin:14px 0 0;font-family:var(--mono);font-size:14px;background:var(--ink);color:#e9e6df;border-radius:10px;padding:14px 16px;overflow-x:auto;line-height:1.6}
.note{margin:18px 0 0;padding:14px 16px;border-radius:10px;background:var(--paper2);font-size:15.5px;color:var(--ink2)}
.note b{color:var(--ink)}
table{width:100%;border-collapse:collapse;margin:16px 0 0;font-size:15.5px}
th,td{text-align:left;padding:10px 8px;border-bottom:1px solid var(--rule);vertical-align:top}
th{font-family:var(--mono);font-size:11.5px;letter-spacing:.06em;text-transform:uppercase;color:var(--ink3);font-weight:500}
.cta{margin:36px 0 0;display:flex;align-items:center;justify-content:space-between;gap:16px;padding:18px 20px;background:var(--ink);color:var(--paper);border-radius:14px;text-decoration:none}
.cta span{display:block;font-family:var(--mono);font-size:11.5px;color:#a9a79f;letter-spacing:.04em}
.cta b{display:block;font-family:var(--sans);font-weight:500;font-size:19px;letter-spacing:-.01em;margin-top:2px}
.cta i{font-style:normal;font-size:22px;transition:transform .2s}
.cta:hover i{transform:translateX(4px)}
.byline{margin:12px 0 0;font-family:var(--mono);font-size:12px;color:var(--ink3)}
.tablewrap{overflow-x:auto;margin:16px 0 0}
.tablewrap table{margin:0;min-width:520px}
.diagram{margin:24px 0 0;padding:20px;background:#fff;border:1px solid var(--rule);border-radius:12px}
.diagram svg{width:100%;height:auto;display:block}
.faqs{margin:40px 0 0}
.faqs h2{margin:0 0 8px}
.faqs details{border-bottom:1px solid var(--rule);padding:14px 0}
.faqs summary{cursor:pointer;font-weight:500;list-style:none;display:flex;justify-content:space-between;gap:16px}
.faqs summary::-webkit-details-marker{display:none}
.faqs summary::after{content:"+";font-family:var(--mono);color:var(--ink3)}
.faqs details[open] summary::after{content:"−"}
.faqs details p{margin:8px 0 0;color:var(--ink2)}
.sources{margin:36px 0 0;padding-top:16px;border-top:1px solid var(--rule)}
.sources h2{margin:0;font-size:13px;font-family:var(--mono);font-weight:500;letter-spacing:.06em;text-transform:uppercase;color:var(--ink3)}
.sources ol{margin:10px 0 0;font-size:14.5px}
.sources a{color:var(--ink2)}
.meta{margin:40px 0 0;padding-top:16px;border-top:1px solid var(--rule);font-family:var(--mono);font-size:12px;color:var(--ink3);display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap}
.more{margin:28px 0 0}
.more h2{font-size:14px;font-family:var(--mono);font-weight:500;letter-spacing:.06em;text-transform:uppercase;color:var(--ink3);margin:0}
.more ul{list-style:none;padding:0;margin:10px 0 0}
.more li{margin:0;padding:10px 0;border-bottom:1px solid var(--rule)}
.more a{text-decoration:none}
.more a:hover{text-decoration:underline}

footer{border-top:1px solid var(--rule);padding:24px 0 36px;font-family:var(--mono);font-size:11.5px;color:var(--ink3)}
footer .wrap{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}
footer a{color:inherit;text-decoration:none}
footer a:hover{color:var(--ink)}