:root {
  color-scheme: light dark;
  --bg: light-dark(#fff, #212121); --surface: light-dark(#f7f7f8, #2f2f2f);
  --surface-strong: light-dark(#fff, #262626); --text: light-dark(#0d0d0d, #ececec);
  --reading-text: light-dark(#404040, #d8d8d8); --active-sentence: light-dark(#f7f7f7, #2b2d2c);
  --muted: light-dark(#6b6b6b, #aaa); --border: light-dark(#e5e5e5, #424242);
  --accent: #10a37f; --accent-soft: light-dark(#eef8f5, #173b32);
  --danger: light-dark(#b42318, #ff8a80); --highlight: light-dark(#fff1a8, #6d5a10);
  --chrome-top: 0px; --chapter-header-height: 116px;
}
* { box-sizing: border-box; }
html { scroll-padding-top: calc(var(--chapter-header-height) + 16px); }
body { margin: 0; overflow-x: hidden; background: var(--bg); color: var(--text); font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", sans-serif; }
button, textarea, select { font: inherit; color: inherit; }
.app-shell { width: min(1160px, 100%); margin: 0 auto; padding: 0 22px 64px; }
.chapter-header {
  position: sticky; top: var(--chrome-top); z-index: 20; display: grid; gap: 8px;
  padding: 13px 0 9px; background: color-mix(in srgb, var(--bg) 92%, transparent);
  border-bottom: 1px solid var(--border); backdrop-filter: blur(10px);
}
.heading-group { min-width: 0; }
.eyebrow, .chapter-meta, .section-label { color: var(--muted); font-size: 11px; }
.chapter-title-row { display: flex; align-items: center; justify-content: space-between; gap: 14px; }
.chapter-controls { display: flex; align-items: center; gap: 7px; }
.heading-group h1 { margin: 2px 0; font: 650 21px/1.25 ui-serif, Georgia, "Noto Serif SC", serif; }
.chapter-picker { border: 1px solid var(--border); border-radius: 7px; background: var(--surface-strong); padding: 5px 8px; font-size: 12px; }
.data-menu { position: relative; color: var(--muted); font-size: 11px; }
.data-menu summary { list-style: none; border: 1px solid var(--border); border-radius: 7px; background: var(--surface-strong); padding: 6px 8px; cursor: pointer; }
.data-menu summary::-webkit-details-marker { display: none; }
.data-menu summary::after { content: " ▾"; }
.data-menu[open] summary::after { content: " ▴"; }
.data-menu-panel { position: absolute; z-index: 40; top: calc(100% + 5px); right: 0; width: 250px; border: 1px solid var(--border); border-radius: 7px; background: var(--surface-strong); padding: 6px; }
.data-menu-panel button { display: block; width: 100%; border: 0; border-radius: 4px; background: transparent; padding: 7px 9px; color: var(--text); font-size: 11px; text-align: left; cursor: pointer; }
.data-menu-panel button:hover, .data-menu-panel button:focus-visible { background: var(--surface); }
.data-menu-label { display: block; padding: 6px 9px 3px; color: var(--muted); font-size: 10px; font-weight: 600; }
.data-menu-panel input { display: block; width: 100%; margin: 3px 0; border: 1px solid var(--border); border-radius: 5px; background: var(--bg); padding: 6px 8px; font-size: 11px; }
.data-menu-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 3px; }
.account-email { display: block; overflow: hidden; padding: 5px 9px; color: var(--text); text-overflow: ellipsis; white-space: nowrap; }
.logic-nav { display: flex; gap: 5px; overflow-x: auto; scrollbar-width: none; }
.logic-nav::-webkit-scrollbar, .annotation-toolbar::-webkit-scrollbar { display: none; }
.toolbar-btn, .tab-btn, .logic-chip { border: 1px solid var(--border); background: var(--surface-strong); border-radius: 7px; cursor: pointer; }
.logic-chip { flex: 0 0 auto; min-width: 31px; padding: 5px 7px; color: var(--muted); font-size: 11px; }
.logic-chip.is-active { color: var(--text); background: var(--surface); border-color: var(--accent); font-weight: 650; }
.reading-layout { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 30px; align-items: start; }
.reading-column, .context-column { min-width: 0; }
.context-column { align-self: stretch; }
.context-sticky { position: sticky; top: calc(var(--chapter-header-height) + 14px); max-height: calc(100vh - var(--chapter-header-height) - 28px); overflow-y: auto; overscroll-behavior: contain; scrollbar-width: thin; padding-top: 14px; }
.annotation-toolbar { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 11px; }
.toolbar-btn { min-height: 31px; padding: 5px 9px; font-size: 11px; }
.toolbar-btn:hover:not(:disabled), .logic-chip:hover { background: var(--surface); }
.toolbar-btn.primary { background: var(--accent); border-color: var(--accent); color: white; }
.toolbar-btn.danger:not(:disabled) { color: var(--danger); }
.toolbar-btn:disabled { cursor: default; opacity: .38; }
.toolbar-btn.is-on { background: var(--accent-soft); border-color: var(--accent); }
.context-card { margin-bottom: 10px; padding: 13px; border: 1px solid var(--border); border-radius: 9px; background: var(--surface); }
.context-card h2 { margin: 0 0 7px; font-size: 12px; }
.collapsible-section h2 { margin: 0; }
.section-toggle { display: flex; width: 100%; align-items: center; justify-content: space-between; border: 0; background: transparent; padding: 0; color: light-dark(#8a8a8a, #a0a0a0); font-size: 12px; font-weight: 500; text-align: left; cursor: pointer; }
.section-toggle:hover, .section-toggle:focus-visible { color: light-dark(#777, #b0b0b0); }
.section-toggle[aria-expanded="true"] { margin-bottom: 7px; }
.section-chevron { width: 7px; height: 7px; margin-right: 2px; border-right: 1px solid light-dark(#aaa, #929292); border-bottom: 1px solid light-dark(#aaa, #929292); font-weight: 400; transform: rotate(45deg); transition: border-color 120ms ease, transform 120ms ease; }
.section-toggle:hover .section-chevron, .section-toggle:focus-visible .section-chevron { border-color: light-dark(#777, #aaa); }
.section-toggle[aria-expanded="false"] .section-chevron { transform: rotate(-45deg); }
.rail-section-body[hidden] { display: none; }
.context-card p { margin: 0; white-space: pre-line; color: var(--reading-text); font-size: 12px; line-height: 1.58; }
.sentence-note { display: block; width: 100%; min-height: 48px; overflow-y: hidden; resize: none; border: 1px solid var(--border); border-radius: 7px; background: var(--bg); padding: 8px 9px; font-size: 12px; line-height: 1.58; }
.status { min-height: 18px; padding: 0 4px; color: var(--muted); font-size: 11px; }
.toast { position: fixed; z-index: 60; right: 22px; bottom: 22px; max-width: min(360px, calc(100vw - 32px)); border: 1px solid var(--border); border-radius: 8px; background: var(--surface-strong); padding: 9px 12px; color: var(--text); box-shadow: 0 2px 10px color-mix(in srgb, #000 12%, transparent); font-size: 12px; }
.sentence-list { max-width: 720px; }
.paragraph-label { scroll-margin-top: calc(var(--chapter-header-height) + 16px); display: flex; justify-content: space-between; gap: 20px; margin: 54px 12px 14px; padding-bottom: 7px; border-bottom: 1px solid var(--border); color: var(--text); font-weight: 650; letter-spacing: .04em; }
.paragraph-label:first-child { margin-top: 20px; }
.page-reference { color: var(--muted); font-weight: 500; }
.sentence-block { scroll-margin-top: calc(var(--chapter-header-height) + 16px); margin-bottom: 10px; padding: 8px 12px; border-radius: 8px; cursor: pointer; }
.sentence-block.is-active { background: var(--active-sentence); }
.sentence-block.is-structure-view { background: light-dark(#f4f7f9, #252a2d); cursor: default; }
.sentence-row { display: grid; grid-template-columns: 26px minmax(0, 1fr); gap: 2px; align-items: start; }
.sentence-content { min-width: 0; }
.sentence-number { padding-top: 6px; color: var(--muted); font: 500 10px/1 ui-sans-serif, system-ui, sans-serif; user-select: none; }
.english-text {
  margin: 0;
  color: var(--reading-text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 16px;
  font-synthesis: none;
  font-weight: 400;
  line-height: 1.74;
}
.sentence-block.is-active .english-text { color: var(--reading-text); font-weight: 400; }
.structure-actions { display: flex; align-items: center; gap: 12px; }
.structure-view-toggle, .structure-reset {
  display: none; margin: 4px 0 0; border: 0; background: transparent; padding: 2px 0;
  color: var(--muted); font-size: 11px; cursor: pointer;
}
.structure-color-setting { display: none; align-items: center; margin-top: 4px; color: var(--muted); font-size: 11px; }
.english-text.is-structured + .structure-actions .structure-color-setting { display: inline-flex; }
.structure-color-setting select { min-height: 21px; border: 0; background: transparent; padding: 1px 0; color: inherit; font-size: 11px; cursor: pointer; }
.structure-color-setting select:hover, .structure-color-setting select:focus-visible { color: var(--text); }
.sentence-block.is-active .structure-view-toggle { display: inline-block; }
.sentence-block.is-active .english-text.is-structured + .structure-actions .structure-reset { display: inline-block; }
.structure-view-toggle:hover, .structure-view-toggle:focus-visible, .structure-reset:hover, .structure-reset:focus-visible { color: var(--text); }
.english-text.is-structured {
  display: grid; gap: 1px; max-width: 100%; padding-left: 42px; overflow-wrap: anywhere;
  color: light-dark(#3f4548, #d3d8da);
  font-family: "SFMono-Regular", Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 13.5px; font-variant-ligatures: none; font-weight: 400; letter-spacing: .015em; line-height: 1.52;
}
.structure-line { position: relative; display: block; min-width: 0; padding-left: calc(16px * var(--structure-level)); outline: none; }
.semantic-connector { pointer-events: none; }
.semantic-connector .structure-break { pointer-events: auto; }
.english-text[data-structure-color="light"] .semantic-connector.causal { color: light-dark(#397a83, #72b7c0); font-weight: 500; }
.english-text[data-structure-color="light"] .semantic-connector.contrast { color: light-dark(#8d644e, #c99577); font-weight: 500; }
.english-text[data-structure-color="light"] .semantic-connector.subordinate { color: light-dark(#746b91, #aaa0ce); font-weight: 500; }
.english-text[data-structure-color="strong"] .semantic-connector.causal { color: light-dark(#087e8b, #39c5d2); font-weight: 600; }
.english-text[data-structure-color="strong"] .semantic-connector.contrast { color: light-dark(#b85c00, #f29a49); font-weight: 600; }
.english-text[data-structure-color="strong"] .semantic-connector.subordinate { color: light-dark(#6f42c1, #b995ff); font-weight: 600; }
.structure-line.is-selected::before { position: absolute; top: .25em; bottom: .25em; left: -7px; width: 2px; border-radius: 1px; background: light-dark(#cbd3d7, #657177); content: ""; }
.structure-line:focus-visible::before { position: absolute; top: .25em; bottom: .25em; left: -7px; width: 2px; background: light-dark(#9ba5aa, #899499); content: ""; }
.structure-line[data-level="0"] { --structure-level: 0; }
.structure-line[data-level="1"] { --structure-level: 1; }
.structure-line[data-level="2"] { --structure-level: 2; }
.structure-line[data-level="3"] { --structure-level: 3; }
.structure-break { appearance: none; position: relative; display: inline-block; width: 0; min-width: 0; height: 0; border: 0; background: transparent; margin: 0; padding: 0; color: transparent; font: inherit; vertical-align: baseline; cursor: pointer; }
.structure-break::before { position: absolute; z-index: 1; top: 50%; left: 0; width: 14px; height: 1.4em; content: ""; transform: translate(-50%, -50%); }
.structure-break::after { position: absolute; z-index: 2; top: 50%; left: 0; opacity: 0; pointer-events: none; color: light-dark(#7c898f, #a4b0b5); content: "|"; font: 11px/1 ui-sans-serif, system-ui, sans-serif; transform: translate(-50%, -50%); transition: opacity 80ms ease; }
.structure-break:hover, .structure-break:focus-visible { outline: none; }
.structure-break:hover::after, .structure-break:focus-visible::after { opacity: 1; }
.structure-break.existing { position: absolute; top: .08em; left: calc(16px * var(--structure-level) - 20px); width: 18px; height: 1.4em; opacity: 0; color: light-dark(#7d8b91, #a3afb3); font: 11px/1 ui-sans-serif, system-ui, sans-serif; transition: opacity 80ms ease; }
.structure-break.existing::before, .structure-break.existing::after { content: none; }
.structure-break.existing:hover, .structure-break.existing:focus-visible { opacity: 1; }
.structure-indent-controls { position: absolute; top: .08em; left: -42px; display: inline-flex; visibility: hidden; opacity: 0; gap: 1px; transition: opacity 100ms ease; }
.structure-line.is-selected > .structure-indent-controls { visibility: visible; opacity: 1; }
.structure-indent-controls button { width: 19px; height: 19px; border: 0; border-radius: 3px; background: transparent; padding: 0; color: var(--muted); font: 11px/1 ui-sans-serif, system-ui, sans-serif; cursor: pointer; }
.structure-indent-controls button:hover:not(:disabled), .structure-indent-controls button:focus-visible { background: var(--surface); color: var(--text); }
.structure-indent-controls button:disabled { opacity: .2; cursor: default; }
.panel-label, .field-label { display: block; margin-bottom: 5px; color: var(--muted); font: 600 10px/1.3 ui-sans-serif, system-ui, sans-serif; }
.translation-context { display: grid; gap: 10px; margin: 9px 0 10px 28px; border-top: 1px solid var(--border); padding-top: 10px; cursor: default; font-family: ui-sans-serif, system-ui, sans-serif; }
.translation-reference-row { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 18px; min-width: 0; }
.translation-layer { min-width: 0; padding: 6px 0; overflow-wrap: anywhere; }
.translation-layer .field-label { color: color-mix(in srgb, var(--muted) 78%, transparent); font-size: 9px; font-weight: 400; letter-spacing: .02em; }
.translation-layer.ai { color: var(--muted); }
.translation-copy { font: 13px/1.65 "Noto Serif SC", ui-serif, serif; }
.user-translation { display: block; width: 100%; min-height: 46px; overflow-y: hidden; resize: none; border: 1px solid var(--border); border-radius: 7px; background: var(--bg); padding: 8px 9px; font: 13px/1.6 "Noto Serif SC", ui-serif, serif; }
.rail-study { padding: 0; overflow: hidden; }
.rail-study[hidden] { display: none; }
.study-tabs { display: flex; padding: 0 8px; border-bottom: 1px solid var(--border); background: var(--surface-strong); }
.tab-btn { border: 0; border-bottom: 2px solid transparent; border-radius: 0; background: transparent; padding: 9px 12px 7px; color: light-dark(#8a8a8a, #9d9d9d); font-size: 12px; font-weight: 400; }
.tab-btn.is-active { color: light-dark(#747474, #adadad); border-bottom-color: var(--accent); font-weight: 500; }
.study-content { padding: 12px; }
.info-stack { display: grid; gap: 8px; }
.info-box { min-width: 0; border: 1px solid var(--border); border-radius: 7px; background: var(--bg); padding: 10px 11px; font-size: 13px; line-height: 1.6; }
.info-box b { display: block; margin-bottom: 4px; color: light-dark(#929292, #9a9a9a); font-size: 12px; font-weight: 400; }
.reading-steps ol { display: grid; gap: 9px; margin: 0; padding-left: 2em; }
.reading-steps li { padding-left: 2px; white-space: pre-line; }
.annotation { cursor: pointer; border-radius: 2px; }
.annotation.highlight { background: var(--highlight); }
.annotation.underline { text-decoration: underline 2px var(--accent); text-underline-offset: 3px; }
.annotation.structure { text-decoration-line: underline; text-decoration-style: dotted; text-decoration-thickness: 1.5px; text-decoration-color: light-dark(#7f9298, #91a4aa); text-underline-offset: 4px; }
.marks-hidden .annotation.highlight { background: transparent; }
.marks-hidden .annotation.underline, .marks-hidden .annotation.structure { text-decoration: none; }

@media (max-width: 900px) {
  :root { --chapter-header-height: 103px; }
  .app-shell { padding-bottom: 76px; }
  .chapter-header { padding-top: 9px; }
  .eyebrow, .chapter-meta { display: none; }
  .reading-layout { grid-template-columns: 1fr; gap: 0; }
  .context-sticky { position: static; max-height: none; overflow: visible; display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
  .context-card { margin: 0; }
  .annotation-toolbar { position: fixed; z-index: 30; right: 0; bottom: 0; left: 0; flex-wrap: nowrap; overflow-x: auto; margin: 0; padding: 8px 12px max(8px, env(safe-area-inset-bottom)); background: color-mix(in srgb, var(--bg) 94%, transparent); border-top: 1px solid var(--border); backdrop-filter: blur(10px); }
  .toolbar-btn { flex: 0 0 auto; }
  .status { grid-column: 1 / -1; }
}
@media (max-width: 650px) {
  :root { --chapter-header-height: 95px; }
  .app-shell { padding-right: 13px; padding-left: 13px; }
  .heading-group h1 { overflow: hidden; margin: 0; font-size: 17px; white-space: nowrap; text-overflow: ellipsis; }
  .chapter-picker { padding: 4px 6px; }
  .logic-nav { margin: 0 -2px; }
  .english-text { font-size: 16px; }
  .translation-context { margin-left: 0; }
  .translation-reference-row { grid-template-columns: 1fr; gap: 10px; }
  .context-sticky { grid-template-columns: 1fr; }
  .status { grid-column: auto; }
  .sentence-block { padding-right: 8px; padding-left: 8px; }
  .english-text.is-structured { padding-left: 40px; }
  .structure-line { padding-left: calc(12px * var(--structure-level)); }
  .structure-break.existing { left: calc(12px * var(--structure-level) - 20px); }
}