:root{--paper:#f4efe4;--paper2:#ebe4d4;--ink:#1f1d1a;--ink2:#4a453e;--rule:#cfc6b3;--acc:#b8460b;--acc-bg:#f7e3d3;--serif:Charter,"Bitstream Charter","Sitka Text",Cambria,"Noto Serif",Georgia,serif;--mono:ui-monospace,"SF Mono",Menlo,Consolas,"DejaVu Sans Mono","Liberation Mono",monospace}
*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}
body{margin:0;font:17px/1.6 var(--serif);color:var(--ink);background:var(--paper)}
.wrap{max-width:920px;margin:0 auto;padding:0 16px}
a{color:var(--ink);text-decoration-color:var(--acc);text-decoration-thickness:2px;text-underline-offset:3px}
a:hover{color:var(--acc)}
:focus-visible{outline:3px solid var(--acc);outline-offset:2px}
.i{display:inline-block;vertical-align:middle;flex:none}
h1,h2,h3{line-height:1.2;font-weight:700}
h1{font-size:2rem;margin:6px 0 10px;letter-spacing:-.01em}
h2{font-size:1.3rem;margin:36px 0 10px;padding-bottom:6px;border-bottom:2px solid var(--ink)}
h3{font-size:1.05rem;margin:22px 0 6px}
p,ul,ol{margin:0 0 12px}
.lbl,.kicker{font:600 .74rem/1.3 var(--mono);letter-spacing:.12em;text-transform:uppercase;color:var(--ink2)}
.muted{color:var(--ink2);font-size:.92rem}
/* masthead: accent band + tape-measure edge */
.mast{background:var(--paper);border-top:6px solid var(--acc)}
.mast .wrap{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:64px}
.tape{height:12px;border-bottom:2px solid var(--ink);background:repeating-linear-gradient(90deg,var(--ink) 0 1px,transparent 1px 8px) bottom/100% 5px no-repeat,repeating-linear-gradient(90deg,var(--ink) 0 2px,transparent 2px 40px) bottom/100% 11px no-repeat}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink)}
.brand .i{color:var(--acc)}
.brand b{font-size:1.45rem;letter-spacing:-.01em}
.brand small{display:block;font:600 .66rem/1.2 var(--mono);letter-spacing:.12em;text-transform:uppercase;color:var(--ink2)}
.mast nav details{position:relative}
.mast summary{list-style:none;cursor:pointer;display:flex;align-items:center;gap:8px;padding:8px 12px;border:2px solid var(--ink);font:600 .8rem var(--mono);letter-spacing:.08em;text-transform:uppercase}
.mast summary::-webkit-details-marker{display:none}
.mast nav ul{position:absolute;right:0;top:calc(100% + 6px);z-index:10;margin:0;padding:0;list-style:none;background:var(--paper);border:2px solid var(--ink);min-width:270px}
.mast nav li+li{border-top:1px solid var(--rule)}
.mast nav li a{display:flex;align-items:center;gap:10px;padding:9px 12px;text-decoration:none}
.mast nav li a[aria-current]{background:var(--acc-bg);font-weight:700}
/* page header */
.crumbs{font:.8rem var(--mono);color:var(--ink2);margin:18px 0 0}.crumbs a{color:var(--ink2)}
.sheet-head{display:grid;grid-template-columns:auto 1fr;gap:14px;align-items:start;margin-top:10px}
.sheet-head .i{color:var(--acc);margin-top:6px}
.meta{font:.8rem var(--mono);color:var(--ink2);margin:0 0 14px;padding:6px 0;border-top:1px solid var(--rule);border-bottom:1px solid var(--rule);display:flex;flex-wrap:wrap;gap:4px 20px}
.lead{font-size:1.05rem;max-width:44em}
/* worksheet */
.sheet{border:2px solid var(--ink);background:#fbf8f1;margin:18px 0}
.sheet>.lbl{display:block;background:var(--ink);color:var(--paper);padding:6px 12px}
#calc{display:grid;grid-template-columns:1fr;margin:0}
@media(min-width:760px){#calc{grid-template-columns:1fr 1fr}#calc>.f:nth-child(odd):not(.full),#calc>span:nth-child(odd)>.f{border-right:1px solid var(--rule)}}
.grid>span,.grid>div.grid{display:contents}
.f{display:grid;grid-template-columns:minmax(0,1fr) minmax(96px,1.15fr);align-items:center;gap:10px;padding:9px 12px;border-bottom:1px solid var(--rule);font-size:.95rem;margin:0}
.f>span{line-height:1.3}
.f small{display:block;font:.74rem var(--mono);color:var(--ink2);margin-top:2px}
input,select{font:600 1rem var(--mono);color:var(--ink);background:var(--paper);border:0;border-bottom:2px solid var(--ink);border-radius:0;padding:7px 6px;width:100%;min-height:40px}
input[type=number]{text-align:right}
select{font:1rem var(--serif);appearance:none;-webkit-appearance:none;padding-right:26px;background:var(--paper) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 32 32'%3E%3Cpath d='M8 12l8 8 8-8' fill='none' stroke='%231f1d1a' stroke-width='3' stroke-linecap='square'/%3E%3C/svg%3E") right 4px center/14px no-repeat}
input:focus,select:focus{outline:3px solid var(--acc);outline-offset:0;background-color:#fff}
.c{display:flex;gap:10px;align-items:center;padding:10px 12px;border-bottom:1px solid var(--rule);font-size:.95rem}
.c input{width:20px;height:20px;min-height:0;accent-color:var(--acc);margin:0}
.gen-row{grid-template-columns:1fr 76px}
.result{padding:14px 12px 12px;border-top:3px double var(--ink);background:#fff}
.result:empty{display:none}
.big{font:700 1.9rem/1.15 var(--mono);color:var(--ink);margin-bottom:6px;padding-left:12px;border-left:6px solid var(--acc)}
.big small{display:block;font:600 .72rem var(--mono);letter-spacing:.1em;text-transform:uppercase;color:var(--ink2);margin-top:4px}
.kv{width:100%;table-layout:fixed;border-collapse:collapse;margin:10px 0 6px;font-size:.93rem}
.kv td{padding:6px 0;border-bottom:1px dotted var(--ink2);vertical-align:top;white-space:normal;overflow-wrap:anywhere}
.kv td:first-child{width:58%;padding-right:10px}
.kv td:last-child{text-align:right;font-family:var(--mono);font-variant-numeric:tabular-nums}
/* boxed notes, with masked SVG icons from the site set */
.warn,.note{position:relative;border:2px solid var(--ink);border-left-width:8px;padding:10px 12px 10px 44px;font-size:.93rem;background:var(--paper)}
.warn{border-color:var(--acc);background:var(--acc-bg)}
.warn::before,.note::before{content:"";position:absolute;left:12px;top:11px;width:22px;height:22px;background:currentColor;-webkit-mask:var(--m) center/contain no-repeat;mask:var(--m) center/contain no-repeat}
.warn{--m:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='32' height='32' viewBox='0 0 32 32' fill='none' stroke='%23000' stroke-width='2.25' stroke-linecap='square' stroke-linejoin='miter'%3E%3Cpath d='M16 3.5L30 28H2z'/%3E%3Cpath d='M16 12v8'/%3E%3Cpath fill='%23000' stroke='none' d='M14.6 22.6h2.8v2.8h-2.8z'/%3E%3C/svg%3E")}.note{--m:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='32' height='32' viewBox='0 0 32 32' fill='none' stroke='%23000' stroke-width='2.25' stroke-linecap='square' stroke-linejoin='miter'%3E%3Ccircle cx='16' cy='16' r='12.5'/%3E%3Cpath d='M16 14v9'/%3E%3Cpath fill='%23000' stroke='none' d='M14.6 8.6h2.8v2.8h-2.8z'/%3E%3C/svg%3E")}
.result .warn,.result .muted{margin-top:8px}
/* article */
.article{counter-reset:sec}
.article h2{counter-increment:sec}
.article h2::before{content:counter(sec) ". ";color:var(--acc)}
.formula{font:.9rem/1.6 var(--mono);background:#fbf8f1;border:1px solid var(--rule);border-left:4px solid var(--ink);padding:8px 12px;overflow-x:auto}
.tablewrap{overflow-x:auto;margin:0 0 12px}
table{border-collapse:collapse;width:100%;font-size:.9rem}
th{font:600 .72rem var(--mono);letter-spacing:.08em;text-transform:uppercase;text-align:left;border-bottom:2px solid var(--ink);padding:6px 8px;vertical-align:bottom}
td{padding:6px 8px;border-bottom:1px solid var(--rule);font-variant-numeric:tabular-nums}
tr:nth-child(even) td{background:#efe8da}
.kv tr:nth-child(even) td{background:none}
.sched summary,.faq summary{cursor:pointer;font-weight:700;padding:10px 0}
.faq details{border-bottom:1px solid var(--rule)}.faq details[open] summary{color:var(--acc)}
.faq p{margin:0 0 12px}
.sources ol{padding-left:22px;font-size:.9rem}.sources li{margin-bottom:4px}
a[target=_blank]::after{content:"";display:inline-block;width:.7em;height:.7em;margin-left:.25em;background:currentColor;-webkit-mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='32' height='32' viewBox='0 0 32 32' fill='none' stroke='%23000' stroke-width='2.25' stroke-linecap='square' stroke-linejoin='miter'%3E%3Cpath d='M14 6H6v20h20v-8'/%3E%3Cpath d='M19 4h9v9M28 4L15 17'/%3E%3C/svg%3E") center/contain no-repeat;mask:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='32' height='32' viewBox='0 0 32 32' fill='none' stroke='%23000' stroke-width='2.25' stroke-linecap='square' stroke-linejoin='miter'%3E%3Cpath d='M14 6H6v20h20v-8'/%3E%3Cpath d='M19 4h9v9M28 4L15 17'/%3E%3C/svg%3E") center/contain no-repeat}
.checked{font:.8rem var(--mono);color:var(--ink2);border-top:1px solid var(--rule);padding-top:8px}
/* directory */
.dir{margin:8px 0 0}
.sys{margin:28px 0 0}
.sys h2{display:flex;align-items:center;gap:10px;margin:0;border-bottom:2px solid var(--ink)}
.sys h2 .i{color:var(--acc)}
.sys h2 .no{font:600 .8rem var(--mono);color:var(--ink2);margin-left:auto}
.rows{list-style:none;margin:0;padding:0}
.rows li{border-bottom:1px solid var(--rule)}
.rows a{display:grid;grid-template-columns:32px 1fr auto;gap:4px 14px;align-items:center;padding:12px 4px;text-decoration:none}
.rows a:hover{background:var(--acc-bg);color:var(--ink)}
.rows b{font-size:1.05rem;text-decoration:underline;text-decoration-color:var(--acc);text-decoration-thickness:2px;text-underline-offset:3px}
.rows span{grid-column:2;color:var(--ink2);font-size:.93rem}
.rows .i{grid-row:span 2}
.rows .go{grid-row:1/span 2;grid-column:3;color:var(--ink2)}
.rows .sh{display:inline-block;text-decoration:none;font:.72rem var(--mono);color:var(--ink2);margin-left:8px;white-space:nowrap}
.howto{counter-reset:n;list-style:none;padding:0}
.howto li{counter-increment:n;padding:8px 0 8px 40px;position:relative;border-bottom:1px solid var(--rule)}
.howto li::before{content:counter(n,decimal-leading-zero);position:absolute;left:0;top:8px;font:700 .9rem var(--mono);color:var(--acc)}
.foot{margin-top:48px;border-top:2px solid var(--ink);padding:16px 0 28px;font-size:.9rem;background:var(--paper2)}
.foot p{margin:0 0 8px}
.foot nav a{margin-right:14px}
@media(max-width:520px){h1{font-size:1.6rem}.brand small{display:none}.f{grid-template-columns:1fr 52%}.big{font-size:1.6rem}.rows .sh{display:none}}
@media print{.mast nav,.foot nav,.related{display:none}body{background:#fff}}
[hidden]{display:none!important}
main.wrap{padding-top:14px}.sys:first-child{margin-top:20px}