/* Reading surfaces: linen outside, a quiet folio inside. Static, no image requests or pointer layer.
   Existing body colors and article metrics stay authoritative. Theme preference changes only these inks. */
:root{--linen-ink:#877659;--linen-tint:#a28b6220;--paper-fiber:#907d5710;--folio:#fffdf7;--folio-edge:#d6ccba;--folio-shadow:#59462d12;--margin-mark:#9a86662e}
/* The ruled body fiber (1px every 5px) is intentionally gone: the linen wash alone is the page material.
   Every color token is unchanged, and --paper-fiber stays declared so the ruling can be restored as-is. */
body{background-image:linear-gradient(100deg,var(--linen-tint),transparent 26%,transparent 74%,var(--linen-tint)),repeating-linear-gradient(92deg,#ffffff1c 0 1px,transparent 1px 7px);background-attachment:scroll}
.site-header{background-image:linear-gradient(90deg,var(--linen-tint),transparent 43%,var(--linen-tint));border-bottom-color:var(--folio-edge)}
main{position:relative;isolation:isolate}
/* Reading-room cover: a strip of laid paper and an engraved plate, not another hero. */
.field-cover{position:relative;isolation:isolate;background:linear-gradient(100deg,var(--folio),transparent 82%);padding-left:27px;border-left:2px solid var(--folio-edge);box-shadow:-9px 0 0 var(--linen-tint)}
.field-cover::after{content:'';position:absolute;right:0;top:0;width:285px;height:100%;z-index:-1;background:repeating-linear-gradient(0deg,var(--margin-mark) 0 1px,transparent 1px 34px);mask-image:linear-gradient(90deg,transparent,#000);opacity:.5;pointer-events:none}
.cover-figure{background:linear-gradient(145deg,var(--folio),transparent);border:1px solid var(--folio-edge);padding:10px;box-shadow:7px 7px 0 var(--linen-tint);rotate:-2deg}
.reading-paths{padding:22px 27px;background:linear-gradient(105deg,var(--folio),color-mix(in srgb,var(--folio) 55%,transparent));border:1px solid var(--folio-edge);box-shadow:5px 5px 0 var(--linen-tint)}
.field-links{border-left:1px solid var(--margin-mark);padding-left:30px}
.method-category-card{background:linear-gradient(115deg,var(--folio),transparent);border-color:var(--folio-edge)}
.method-category-card:hover{background:var(--folio)}
/* The printed column remains near-uniform. Texture lives at the sheet edge and outside the column. */
.reading-mode .reading-paths{padding:0;border:0;box-shadow:none;background:none}
.method-card__preview[data-state="ready"]{position:relative;isolation:isolate;background:transparent}
.method-card__preview[data-state="ready"]::before{content:'';position:absolute;z-index:-1;top:0;bottom:-30px;left:-25px;right:-25px;pointer-events:none;background:linear-gradient(90deg,color-mix(in srgb,var(--folio-edge) 17%,var(--folio)),var(--folio) 22px,var(--folio) calc(100% - 18px),color-mix(in srgb,var(--folio-edge) 14%,var(--folio)));border:1px solid var(--folio-edge);box-shadow:7px 8px 0 var(--linen-tint),0 16px 28px var(--folio-shadow)}
.reading-toolbar{background:linear-gradient(180deg,var(--folio),transparent);border-bottom-color:var(--folio-edge);padding-top:8px}
.method-card__preview--html{background:transparent}
.reader-toc summary{border-bottom-color:var(--folio-edge)}
.reader-toc a[data-reading-current]{background:color-mix(in srgb,var(--teal) 8%,var(--paper));border-left-width:2px}
.method-card__preview--html:not(:has(.page)) h2{border-top-color:var(--folio-edge)}
.reader-return{background:var(--folio);border-color:var(--folio-edge);box-shadow:3px 4px 0 var(--linen-tint)}
.site-footer{background-image:linear-gradient(90deg,var(--linen-tint),transparent 45%);border-top-color:var(--folio-edge)}
@media(min-width:1100px){
 .method-card__preview[data-state="ready"]::before{left:260px;right:-28px;top:72px}
 .reading-toolbar{background:none;padding-top:0}
 .reader-toc{border-right:1px solid var(--margin-mark)}
 .method-card__preview>.method-card__preview--html{padding-top:30px}
}
@media(max-width:1099px){
 .method-card__preview[data-state="ready"]{padding-top:15px}
 .method-card__preview[data-state="ready"]::before{left:-20px;right:-20px;bottom:-25px}
 .field-cover{padding-left:20px}.reading-paths{padding:18px 20px}.field-links{padding-left:20px}
}
@media(max-width:760px){
 .field-links{border-left:0;border-top:1px solid var(--margin-mark);padding:24px 0 0}
 .field-cover::after{width:46%;opacity:.3}
 .reading-paths{padding:16px 20px}
 .reading-mode .reading-paths{padding:0}
}
@media(max-width:520px){
 body{background-image:linear-gradient(90deg,var(--linen-tint),transparent 17%,transparent 83%,var(--linen-tint))}
 .field-cover{padding-left:17px;padding-top:15px;padding-bottom:23px;box-shadow:-6px 0 0 var(--linen-tint)}
 .field-cover h1{font-size:32px}.cover-intro{font-size:14px}
 .reading-paths{padding:14px 16px}.product-tab--doc .method-card__title{font-size:23px}
 .reading-mode .method-card__preview[data-state="ready"]{padding-top:8px}
 .method-card__preview[data-state="ready"]::before{left:-12px;right:-12px;bottom:-22px;box-shadow:4px 5px 0 var(--linen-tint),0 9px 20px var(--folio-shadow)}
 .reading-toolbar{padding-top:0}
 .reading-mode .product-tab--doc .method-card__title{font-size:25px}
}
/* The user's explicit theme wins over the OS. No image/filter inversion of the original logo. */
@media(prefers-color-scheme:dark){:root:not([data-reader-theme="light"]){--linen-ink:#ac9e82;--linen-tint:#b8a2740c;--paper-fiber:#ddc6a408;--folio:#272723;--folio-edge:#454236;--folio-shadow:#0000002a;--margin-mark:#aa9a782b}}
:root[data-reader-theme="dark"]{--linen-ink:#ac9e82;--linen-tint:#b8a2740c;--paper-fiber:#ddc6a408;--folio:#272723;--folio-edge:#454236;--folio-shadow:#0000002a;--margin-mark:#aa9a782b}
@media(forced-colors:active){body,.site-header,.site-footer,.field-cover,.reading-paths,.reading-toolbar,.method-category-card{background:Canvas!important;box-shadow:none;border-color:CanvasText}.field-cover::after,.method-card__preview[data-state="ready"]::before{display:none}.reader-toc{border-color:CanvasText}.reader-return{background:Canvas;box-shadow:none}}
@media print{body,main,.site-header,.site-footer,.reading-paths,.method-card__preview,.reading-toolbar{background:white!important;box-shadow:none}.field-cover::after,.method-card__preview[data-state="ready"]::before{display:none!important}.method-card__preview>.method-card__preview--html{padding:0!important}.reading-paths{padding:0!important;border:0}}

/* Dark reader surfaces stay solid: remove the linen/folio paper texture while keeping the editorial layout. */
@media(prefers-color-scheme:dark){
 :root:not([data-reader-theme="light"]){--linen-tint:transparent;--folio:#121713;--folio-edge:#39463d;--folio-shadow:transparent;--margin-mark:transparent}
 :root:not([data-reader-theme="light"]) body{background-image:none}
 :root:not([data-reader-theme="light"]) .site-header{background-image:none}
 :root:not([data-reader-theme="light"]) .site-footer{background-image:none}
 :root:not([data-reader-theme="light"]) .field-cover::after,
 :root:not([data-reader-theme="light"]) .method-card__preview[data-state="ready"]::before{display:none}
}
:root[data-reader-theme="dark"]{--linen-tint:transparent;--folio:#121713;--folio-edge:#39463d;--folio-shadow:transparent;--margin-mark:transparent}
:root[data-reader-theme="dark"] body{background-image:none}
:root[data-reader-theme="dark"] .site-header,
:root[data-reader-theme="dark"] .site-footer{background-image:none}
:root[data-reader-theme="dark"] .field-cover::after,
:root[data-reader-theme="dark"] .method-card__preview[data-state="ready"]::before{display:none}


/* Editorial shape contract: this file is loaded last and owns shared surface geometry.
   Product branches must not reintroduce rounded cards through the older base layer. */
:is(.method-card__preview,.method-card__toggle,.reader-retry,.reader-tools input,.reader-return,.reading-paths,.method-category-card,.reader-theme-picker>summary){border-radius:0}
.site-header__parent-brand img,.site-header__logo{border-radius:0}