.reader-shell { padding-top: 36px; }
.reader-breadcrumb { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin-bottom: 30px; color: var(--text-faint); font-size: 13px; }
.reader-breadcrumb a:hover { color: var(--accent-strong); }
.reader-layout { display: grid; grid-template-columns: 200px minmax(0, 1fr); gap: 64px; padding-bottom: 64px; }
.reader-layout, .reader-main { min-width: 0; }
.reader-sidebar { position: sticky; top: calc(var(--header-height) + 28px); align-self: start; min-width: 0; }
.toc-panel summary { list-style: none; display: flex; justify-content: space-between; font-size: 11px; letter-spacing: .13em; font-weight: 650; color: var(--text-faint); padding-bottom: 18px; }
.toc-panel summary::-webkit-details-marker { display: none; }
.toc-panel summary > span { display: none; }
#reader-toc { max-height: calc(100vh - 400px); overflow: auto; scrollbar-width: thin; border-left: 1px solid var(--line); }
#reader-toc a { display: block; font-size: 12px; line-height: 1.65; padding: 8px 8px 8px 17px; border-left: 2px solid transparent; margin-left: -1px; color: var(--text-soft); transition: color 150ms, border-color 150ms; }
#reader-toc a.is-current { color: var(--accent-strong); border-left-color: var(--accent); font-weight: 600; background: var(--accent-soft); }
#reader-toc a[data-depth="3"] { padding-left: 28px; font-size: 11px; }
.reading-tools { margin-top: 30px; padding-top: 20px; border-top: 1px solid var(--line); color: var(--text-faint); font-size: 11px; }
.reading-tools > div { display: flex; align-items: center; gap: 10px; margin: 12px 0; }
.reading-tools > div > :first-child { margin-right: auto; }
.reading-size button { background: var(--surface); color: var(--text-soft); width: 31px; height: 28px; border: 1px solid var(--line); border-radius: 4px; cursor: pointer; }
.reader-main { min-width: 0; }
.article-kicker { display: flex; justify-content: space-between; align-items: center; gap: 16px; font: 10px var(--font-mono); letter-spacing: .12em; color: var(--text-faint); text-transform: uppercase; }
.article-kicker a { color: var(--accent-strong); font-family: var(--font-editorial); font-size: 12px; letter-spacing: .02em; }
.article-heading h1 { margin: 26px 0; font: 500 clamp(28px, 3.3vw, 42px)/1.45 var(--font-editorial); letter-spacing: -.035em; text-wrap: balance; }
.article-byline { display: flex; align-items: center; gap: 12px; color: var(--text-soft); font-size: 12px; }
.byline-separator { color: var(--line-strong); margin: 0 3px; }
#reader-length { margin-left: auto; color: var(--text-faint); font-size: 11px; }
.reader-series { display: inline-block; margin-top: 22px; font-size: 12px; color: var(--accent-strong); }
.reader-series[hidden] { display: none; }
.reader-actions { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 15px; border-bottom: 1px solid var(--line-strong); margin-top: 33px; }
.reader-actions[hidden], .equation-return[hidden], .reader-content[hidden], .markdown-source[hidden] { display: none; }
.reader-tabs, .reader-file-actions { display: flex; align-items: center; gap: 20px; }
.reader-tabs button { padding: 15px 0; position: relative; background: transparent; color: var(--text-faint); font-size: 12px; cursor: pointer; }
.reader-tabs button[aria-pressed="true"] { color: var(--accent-strong); font-weight: 600; }
.reader-tabs button[aria-pressed="true"]::after { content: ""; position: absolute; bottom: -1px; left: 0; right: 0; height: 2px; background: var(--accent); }
.reader-file-actions { gap: 10px; flex-wrap: wrap; }
#reader-progress { margin-left: auto; }
#reader-copy-status { color: var(--text-faint); font-size: 12px; line-height: 1.7; }
#reader-copy-status:empty { display: none; }
.reader-file-actions :is(button, a) { padding: 9px 13px; border-radius: 5px; font-size: 11px; cursor: pointer; white-space: nowrap; }
.reader-copy { color: #fff; background: var(--accent-strong); }
.reader-download { color: var(--text-soft); background: var(--surface); border: 1px solid var(--line); }
.reader-file-actions :is(button, a) span { margin-left: 8px; }
.reader-gpt-actions { position: relative; display: flex; align-items: stretch; }
.reader-gpt-actions > a { border-radius: 5px 0 0 5px; }
.reader-gpt-options summary { display: grid; place-items: center; height: 100%; min-width: 30px; padding: 0 8px; list-style: none; border: 1px solid var(--line); border-left: 0; border-radius: 0 5px 5px 0; background: var(--surface); color: var(--text-soft); cursor: pointer; }
.reader-gpt-options summary::-webkit-details-marker { display: none; }
.reader-gpt-options summary svg { width: 14px; height: 14px; fill: none; stroke: currentColor; stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; }
.reader-gpt-options[open] summary { color: var(--accent-strong); background: var(--accent-soft); }
.reader-gpt-options[open] summary svg { transform: rotate(180deg); }
.reader-gpt-options summary:focus-visible, .reader-gpt-menu button:focus-visible, .selection-actions a:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.reader-gpt-menu { position: absolute; z-index: 50; top: calc(100% + 8px); left: 0; width: min(316px, calc(100vw - 32px)); padding: 12px; overflow-y: auto; overscroll-behavior: contain; scrollbar-width: thin; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); box-shadow: var(--shadow-tight); }
.ai-menu-heading { margin: 3px 7px 12px; color: var(--text-faint); font-size: 11px; font-weight: 500; letter-spacing: .04em; }
.ai-provider-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 5px; }
.reader-gpt-menu .ai-provider-option { display: flex; align-items: center; gap: 8px; min-width: 0; min-height: 42px; padding: 10px 8px; border: 1px solid transparent; border-radius: 5px; background: transparent; color: var(--text-soft); font-size: 12px; text-align: left; }
.reader-gpt-menu .ai-provider-option[aria-checked="true"] { border-color: color-mix(in srgb, var(--accent) 24%, transparent); background: var(--accent-soft); color: var(--accent-strong); }
.ai-provider-icon { display: inline-flex; flex: 0 0 18px; width: 18px; height: 18px; background-color: currentColor; -webkit-mask-image: var(--ai-icon); mask-image: var(--ai-icon); -webkit-mask-position: center; mask-position: center; -webkit-mask-size: contain; mask-size: contain; -webkit-mask-repeat: no-repeat; mask-repeat: no-repeat; }
#ask-gpt, .selection-actions a, #gpt-handoff-open, #gpt-handoff-title { display: inline-flex; align-items: center; gap: 8px; }
#ask-gpt > .ai-provider-icon, .selection-actions .ai-provider-icon, #gpt-handoff-open > .ai-provider-icon { flex-basis: 15px; width: 15px; height: 15px; }
.reader-file-actions :is(.ai-provider-icon, .ai-action-label, .ai-provider-name, .ai-provider-default) { display: inline-flex; margin: 0; }
.reader-file-actions .ai-action-arrow { margin: 0; color: var(--text-faint); }
.reader-gpt-menu .ai-provider-default { font-size: 9px; color: var(--text-faint); }
.ai-provider-check { flex: 0 0 12px; width: 12px; height: 12px; margin-left: auto; fill: none; stroke: currentColor; stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; visibility: hidden; }
.ai-provider-option[aria-checked="true"] .ai-provider-check { visibility: visible; }
.ai-menu-footer { margin-top: 12px; padding-top: 9px; border-top: 1px solid var(--line); }
.reader-gpt-menu .ai-copy-full { display: flex; align-items: center; gap: 9px; width: 100%; padding: 9px 7px; background: transparent; color: var(--text-soft); font-size: 12px; text-align: left; }
.ai-copy-full svg { flex: 0 0 16px; width: 16px; height: 16px; fill: none; stroke: currentColor; stroke-width: 1.3; stroke-linejoin: round; }
.reader-gpt-menu .ai-copy-full span { display: inline; margin-left: auto; color: var(--text-faint); }
#ai-provider-hint { margin: 5px 7px 2px; color: var(--text-faint); font-size: 10px; line-height: 1.6; }
.reader-file-actions .reader-gpt-menu button:is(:hover, :active) { transform: none; box-shadow: none; }
.reader-file-actions .reader-gpt-actions > a:is(:hover, :active) { transform: none; box-shadow: none; }
@media (hover: hover) {
  .reader-gpt-options summary:hover { color: var(--accent-strong); }
  .reader-gpt-menu .ai-provider-option:hover:not([aria-checked="true"]), .reader-gpt-menu .ai-copy-full:hover { background: var(--surface-soft); color: var(--text); }
}
.selection-actions { position: fixed; z-index: 60; padding: 4px; border: 1px solid var(--line-strong); border-radius: 7px; background: var(--surface); box-shadow: var(--shadow-tight); }
.selection-actions[hidden], body.drawer-open .selection-actions { display: none; }
.selection-actions a { padding: 9px 13px; color: var(--accent-strong); font: 12px/1.6 var(--font-editorial); white-space: nowrap; }
body.gpt-handoff-open { overflow: hidden; }
.gpt-handoff { width: min(700px, calc(100vw - 32px)); max-height: calc(100dvh - 40px); margin: auto; padding: 24px; border: 1px solid var(--line-strong); border-radius: 8px; background: var(--surface); color: var(--text); box-shadow: var(--shadow); }
.gpt-handoff::backdrop { background: rgb(10 16 30 / .65); }
.gpt-handoff-heading { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.gpt-handoff-heading h2 { margin: 0; font: 500 20px/1.5 var(--font-editorial); }
#gpt-handoff-title { gap: 10px; }
#gpt-handoff-title .ai-provider-icon { flex-basis: 22px; width: 22px; height: 22px; color: var(--accent-strong); }
.gpt-handoff-heading button { display: grid; place-items: center; flex: 0 0 32px; width: 32px; height: 32px; padding: 0; border-radius: 4px; background: transparent; color: var(--text-faint); font-size: 22px; line-height: 1; cursor: pointer; }
.gpt-handoff-heading button:hover { background: var(--surface-soft); color: var(--text); }
#gpt-handoff-note, #gpt-handoff-status { font-size: 12px; line-height: 1.8; color: var(--text-soft); }
#gpt-handoff-status:empty { display: none; }
#gpt-handoff-text { display: block; width: 100%; height: min(380px, 45dvh); padding: 16px; margin: 18px 0; border: 1px solid var(--line); border-radius: 5px; background: var(--surface-soft); color: var(--text); resize: vertical; font: 12px/1.8 var(--font-mono); }
.gpt-handoff-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.gpt-handoff-actions :is(button, a) { padding: 10px 12px; border: 1px solid var(--line); border-radius: 5px; font-size: 12px; cursor: pointer; }
.gpt-handoff-actions :is(button, a):not(.reader-copy) { background: var(--surface); color: var(--text-soft); }
#reader-status { min-height: 18px; color: var(--text-faint); font-size: 12px; line-height: 1.7; margin: 13px 0 30px; }
.reader-content { font: var(--reading-size, 18px)/1.95 var(--font-editorial); letter-spacing: .005em; overflow-wrap: anywhere; }
.reader-content > h1 { display: none; }
.reader-content p { margin: 1.3em 0; }
.reader-content > :first-child { margin-top: 0; }
.reader-content h2 { font: 600 25px/1.55 var(--font-editorial); margin: 2.7em 0 1em; padding-top: 25px; border-top: 1px solid var(--line); }
.reader-content h3 { font: 600 21px/1.6 var(--font-editorial); margin: 2em 0 .8em; }
.reader-content h4 { font-size: 19px; }
.reader-content :is(h1,h2,h3,h4,h5,h6) { scroll-margin-top: 112px; }
.reader-content a { color: var(--accent-strong); text-decoration: underline; text-decoration-color: color-mix(in srgb, var(--accent) 35%, transparent); text-underline-offset: 4px; }
.reader-content blockquote { border-left: 2px solid var(--accent); padding: 4px 22px; margin: 28px 0; color: var(--text-soft); background: var(--surface-soft); font-size: .95em; }
.reader-content img { display: block; max-width: 100%; max-height: 50vh; max-height: 50dvh; width: auto; height: auto; margin: 30px auto; border-radius: 3px; cursor: zoom-in; }
.reader-content img:focus-visible { outline: 2px solid var(--accent); outline-offset: 4px; }
body.image-viewer-open { overflow: hidden; }
.image-viewer { width: min(1280px, calc(100vw - 40px)); height: calc(100dvh - 48px); max-width: none; max-height: none; padding: 0; margin: auto; border: 1px solid var(--line-strong); border-radius: 8px; background: var(--surface); color: var(--text); box-shadow: var(--shadow); }
.image-viewer[open] { display: flex; flex-direction: column; }
.image-viewer::backdrop { background: rgb(10 16 30 / .72); }
.image-viewer-toolbar { display: flex; flex: none; align-items: center; gap: 12px; padding: 12px 16px; border-bottom: 1px solid var(--line); font-size: 12px; }
#image-viewer-title { margin-right: auto; color: var(--text-soft); }
.image-viewer-toolbar :is(button, a) { padding: 8px 10px; border: 1px solid var(--line); border-radius: 4px; background: var(--surface); color: var(--text-soft); cursor: pointer; white-space: nowrap; }
.image-viewer-toolbar :is(button, a):hover:not(:disabled) { border-color: var(--accent); color: var(--accent-strong); }
.image-viewer-toolbar button:disabled { opacity: .4; cursor: default; }
.image-viewer-zoom { display: flex; align-items: center; gap: 4px; }
.image-viewer-zoom button { min-width: 34px; font-size: 16px; line-height: 1; }
#image-viewer-scale { min-width: 48px; text-align: center; font-variant-numeric: tabular-nums; color: var(--text-soft); }
.image-viewer-stage { position: relative; flex: 1; min-height: 0; min-width: 0; overflow: hidden; touch-action: none; user-select: none; }
.image-viewer-stage.can-pan { cursor: grab; }
.image-viewer-stage.is-dragging { cursor: grabbing; }
.image-viewer-stage:focus-visible { outline: 2px solid var(--accent); outline-offset: -4px; }
#image-viewer-image { position: absolute; left: 50%; top: 50%; display: block; max-width: none; max-height: none; transform-origin: center; user-select: none; -webkit-user-drag: none; }
#image-viewer-caption { flex: none; max-height: 5em; overflow: auto; margin: 0; padding: 10px 20px 16px; color: var(--text-soft); font-size: 12px; line-height: 1.6; text-align: center; }
@media (max-width: 760px) {
  .image-viewer { width: calc(100vw - 16px); height: calc(100dvh - 24px); }
  .image-viewer-toolbar { flex-wrap: wrap; gap: 6px; padding: 10px; font-size: 11px; }
  #image-viewer-title { flex: 1 0 calc(100% - 80px); }
  .image-viewer-zoom, #image-viewer-size, #image-viewer-original { order: 1; }
  .image-viewer-toolbar :is(button, a) { padding: 8px; }
}
.reader-content .reader-figure { margin: 30px 0; text-align: center; }
.reader-content .reader-figure > :first-child { margin: 0; }
.reader-content .captioned-image { margin: 0 auto; }
.reader-content .image-caption { margin: 10px auto 0; padding: 0 12px; max-width: 64em; color: var(--text-soft); font-size: .78em; line-height: 1.65; text-align: center; }
.reader-content pre { position: relative; padding: 24px; background: var(--surface-soft); border: 1px solid var(--line); border-radius: 7px; overflow-x: auto; white-space: pre; font: 13px/1.9 var(--font-mono); letter-spacing: 0; }
.reader-content code { font-family: var(--font-mono); font-size: .85em; }
.reader-content pre code { font-size: inherit; }
.reader-content video, .reader-content audio { display: block; max-width: 100%; margin: 28px auto; }
.reader-content .table-scroll { max-width: 100%; overflow-x: auto; margin: 30px 0; border: 1px solid var(--line); border-radius: 6px; }
.reader-content table { border-collapse: collapse; min-width: 100%; font: 13px/1.8 var(--font-editorial); }
.reader-content th, .reader-content td { border-bottom: 1px solid var(--line); padding: 11px 16px; min-width: 84px; text-align: left; }
.reader-content tr:first-child { background: var(--surface-soft); color: var(--accent-strong); }
.reader-content tr:last-child td { border-bottom: 0; }
.reader-content mjx-container { max-width: 100%; letter-spacing: normal; }
.reader-content mjx-container:not([display="true"]) { display: inline-block; margin-inline: .18em; max-width: calc(100% - .36em); }
.reader-content mjx-container.math-inline-overflow { vertical-align: middle; overflow-x: auto; overflow-y: hidden; padding-block: .15em; }
.reader-content mjx-container[data-latex] { cursor: text; user-select: text; }
.reader-content mjx-container[data-latex]:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.reader-content .math-scroll { display: block; max-width: 100%; overflow-x: auto; overflow-y: hidden; margin: 20px 0; }
.reader-content :is(.math-scroll, mjx-container) { scroll-margin-top: calc(var(--header-height) + 24px); }
.reader-content .is-equation-target { background: var(--accent-soft); outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 3px; }
.equation-return { position: fixed; z-index: 45; right: 88px; bottom: max(28px, env(safe-area-inset-bottom)); padding: 12px 16px; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--surface); color: var(--accent-strong); box-shadow: 0 4px 18px rgb(0 0 0 / .08); font-size: 12px; cursor: pointer; }
.equation-return:hover { border-color: var(--accent); }
.equation-return:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
body.drawer-open .equation-return { visibility: hidden; }
.equation-preview { position: fixed; z-index: 120; width: min(560px, calc(100vw - 24px)); padding: 14px 18px 18px; border: 1px solid var(--line-strong); border-radius: 8px; background: var(--surface); color: var(--text); box-shadow: var(--shadow-tight); }
.equation-preview[hidden] { display: none; }
.equation-preview-heading { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 14px; font-size: 11px; line-height: 1.6; color: var(--text-faint); }
.equation-preview-heading strong { font-weight: 600; color: var(--accent-strong); }
.equation-preview-content { max-height: min(280px, 42dvh); overflow: auto; padding: 5px 2px 9px; font-size: 18px; scrollbar-width: thin; }
.equation-preview-content mjx-container[display="true"] { margin: 0 !important; }
/* The outer .math-scroll owns scrolling, including MathJax's table min-width. */
.reader-content mjx-container[display="true"] { overflow: visible; max-width: 100%; padding: 12px 0; }
.reader-content hr { border: 0; border-top: 1px solid var(--line); margin: 30px 0; }
.source-warnings, .source-attachment { display: block; border: 1px solid var(--line); border-radius: 6px; padding: 14px 18px; margin: 24px 0; color: var(--text-soft); font: 12px/1.85 var(--font-editorial); }
.source-warnings p { margin: 5px 0; }
.source-attachment summary { cursor: pointer; }
.markdown-source { display: block; resize: vertical; width: 100%; min-height: 72vh; margin: 24px 0; border: 1px solid var(--line); border-radius: 8px; padding: 24px; background: var(--surface); color: var(--text); font: 13px/1.9 var(--font-mono); tab-size: 2; }
.series-pagination { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 64px; }
.series-pagination a { padding: 22px; border: 1px solid var(--line); border-radius: 7px; background: var(--surface); transition: border-color 150ms; }
.series-pagination a:hover { border-color: var(--accent); }
.series-pagination span { display: block; font: 10px var(--font-editorial); color: var(--text-faint); margin-bottom: 10px; }
.series-pagination strong { font: 500 15px/1.7 var(--font-editorial); }
.reader-footer { border-top: 1px solid var(--line-strong); margin-top: 44px; padding-top: 26px; color: var(--text-faint); font-size: 11px; line-height: 1.9; }
.reader-attribution summary { cursor: pointer; color: var(--text-soft); padding: 5px 0; }
.reader-attribution blockquote { margin: 12px 0; padding: 14px 20px; background: var(--surface-soft); }
.reader-license { font-size: 10px; }
@media (max-width: 1050px) {
  .reader-layout { gap: 40px; grid-template-columns: 170px minmax(0, 1fr); }
  .reader-file-actions { order: -1; flex-basis: 100%; }
}
@media (max-width: 760px) {
  .reader-shell { padding-top: 22px; }
  .reader-breadcrumb { gap: 8px; margin-bottom: 20px; font-size: 12px; }
  .reader-layout { display: flex; flex-direction: column; padding: 0 0 48px; gap: 28px; }
  .reader-sidebar { width: 100%; position: static; }
  .reading-tools { display: flex; justify-content: space-between; gap: 20px; margin-top: 10px; padding-top: 0; border-top: 0; }
  .reading-tools > div { margin: 4px 0; }
  .toc-panel { border-bottom: 1px solid var(--line); padding-bottom: 12px; }
  .toc-panel summary { cursor: pointer; padding: 0; } .toc-panel summary > span { display: inline; }
  #reader-toc { margin-top: 14px; max-height: 35vh; } .article-heading h1 { font-size: 29px; margin: 20px 0; }
  .article-byline { font-size: 11px; gap: 9px; } #reader-length { font-size: 10px; }
  .reader-actions { gap: 6px; margin-top: 26px; }
  .reader-file-actions { gap: 8px; }
  .reader-tabs { gap: 16px; }
  .equation-return { right: 76px; bottom: calc(88px + env(safe-area-inset-bottom)); }
  .reader-file-actions :is(button, a) { padding: 9px; font-size: 10px; } .reader-file-actions :is(button, a) span { display: none; }
  .gpt-handoff { padding: 20px; }
  .gpt-handoff-heading h2 { font-size: 18px; }
  #gpt-handoff-title { gap: 8px; }
  #gpt-handoff-title .ai-provider-icon { flex-basis: 20px; width: 20px; height: 20px; }
  .reader-tabs button { font-size: 11px; } .reader-content { font-size: calc(var(--reading-size, 18px) - 1px); }
  .reader-content h2 { font-size: 23px; } .reader-content pre { padding: 18px; font-size: 12px; }
  .series-pagination { gap: 10px; } .series-pagination a { padding: 16px; } .series-pagination strong { font-size: 13px; }
}

html[data-theme="dark"] .reader-copy { color: var(--bg); }

@media (prefers-reduced-motion: no-preference) {
  .reader-gpt-options summary svg { transition: transform 160ms ease; }
  .reader-file-actions :is(button, a), .reading-size button, .equation-return {
    transition: transform 160ms ease, border-color 180ms ease, background-color 180ms ease, box-shadow 180ms ease;
  }
  .reader-tabs button { transition: color 180ms ease; }
  .reader-tabs button::after { transform-origin: left; animation: reader-tab-in 180ms ease backwards; }
  .equation-return:not([hidden]) { animation: return-arrive 200ms ease backwards; }
  .series-pagination a { transition: transform 180ms ease, border-color 180ms ease, box-shadow 180ms ease; }
  .reader-file-actions :is(button, a):active, .reading-size button:active { transform: scale(.97); }
  @media (hover: hover) and (pointer: fine) {
    .reader-file-actions :is(button, a):hover, .series-pagination a:hover { transform: translateY(-2px); box-shadow: var(--shadow-tight); }
    .reader-file-actions :is(button, a):active { transform: translateY(0) scale(.97); }
  }
}
@keyframes reader-tab-in { from { transform: scaleX(0); } to { transform: scaleX(1); } }
@keyframes return-arrive { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }