/* Layout: one reading column (~40rem) with a phone-style bottom tab bar; cards only for navigation. */
@font-face { font-family: "Literata"; src: url("/fonts/literata.woff2") format("woff2"); font-weight: 300 800; font-style: normal; font-display: swap; }
@font-face { font-family: "Literata"; src: url("/fonts/literata-italic.woff2") format("woff2"); font-weight: 300 800; font-style: italic; font-display: swap; }
@font-face { font-family: "Instrument Sans"; src: url("/fonts/instrument-sans.woff2") format("woff2"); font-weight: 500 700; font-display: swap; }
@font-face { font-family: "JetBrains Mono"; src: url("/fonts/jetbrains-mono.woff2") format("woff2"); font-weight: 400 700; font-display: swap; }

:root {
  --bg: #f4f5f2;
  --surface: #ffffff;
  --sunken: #eaece7;
  --ink: #1a2129;
  --muted: #5a6570;
  --line: #d9ddd7;
  --accent: #0a6a70;
  --accent-ink: #ffffff;
  --accent-soft: #d9ecea;
  --deep: #9a5b06;
  --deep-soft: #f5e7cf;
  --good: #1f7a49;
  --good-soft: #d8efe1;
  --bad: #b23a2c;
  --bad-soft: #f6dcd8;
  --code-bg: #eceee9;
  --mark: #fbe3a6;
  --fs: 18px;
  --serif: "Literata", "Iowan Old Style", "Charter", Georgia, "Noto Serif", serif;
  --sans: "Instrument Sans", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --col: 40rem;
  --tabs-h: 60px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #11161b; --surface: #182028; --sunken: #0d1216; --ink: #e3e8ec; --muted: #94a1ad; --line: #2a343e;
    --accent: #66c9c9; --accent-ink: #0b1a1b; --accent-soft: #19363a; --deep: #e6b24f; --deep-soft: #3a2f19;
    --good: #6fca93; --good-soft: #193526; --bad: #f08c7e; --bad-soft: #3d1f1b; --code-bg: #0d1318; --mark: #5a4614;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #11161b; --surface: #182028; --sunken: #0d1216; --ink: #e3e8ec; --muted: #94a1ad; --line: #2a343e;
  --accent: #66c9c9; --accent-ink: #0b1a1b; --accent-soft: #19363a; --deep: #e6b24f; --deep-soft: #3a2f19;
  --good: #6fca93; --good-soft: #193526; --bad: #f08c7e; --bad-soft: #3d1f1b; --code-bg: #0d1318; --mark: #5a4614;
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: 72px; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 400 var(--fs)/1.65 var(--serif);
  padding-bottom: calc(var(--tabs-h) + env(safe-area-inset-bottom, 0px) + 24px);
  -webkit-font-smoothing: antialiased;
}
@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }
[hidden] { display: none !important; }
a { color: var(--accent); text-underline-offset: 0.18em; text-decoration-thickness: 1px; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }
img { max-width: 100%; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }

/* ---------- top bar */
.top {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding-top: env(safe-area-inset-top, 0px);
  padding-left: max(16px, env(safe-area-inset-left, 0px)); padding-right: max(16px, env(safe-area-inset-right, 0px));
  height: calc(52px + env(safe-area-inset-top, 0px));
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(1.4) blur(10px); -webkit-backdrop-filter: saturate(1.4) blur(10px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font: 600 16px/1 var(--sans); letter-spacing: 0.01em; }
.mark { display: inline-flex; align-items: center; gap: 2px; height: 20px; }
.mark i { display: block; width: 3px; border-radius: 2px; background: var(--accent); }
.mark i:nth-child(1) { height: 7px; } .mark i:nth-child(2) { height: 14px; } .mark i:nth-child(3) { height: 20px; background: var(--deep); }
.mark i:nth-child(4) { height: 12px; } .mark i:nth-child(5) { height: 6px; }
.top-actions { display: flex; gap: 4px; }
.iconbtn { display: grid; place-items: center; width: 40px; height: 40px; border-radius: 10px; color: var(--muted); }
.iconbtn:hover { background: var(--sunken); color: var(--ink); }
.ico { width: 22px; height: 22px; flex: none; }

.readbar { position: fixed; top: 0; left: 0; right: 0; height: 3px; z-index: 30; pointer-events: none; }
.readbar i { display: block; height: 100%; width: 0; background: var(--accent); transition: width 80ms linear; }
body:not(.is-paper) .readbar { display: none; }

/* ---------- bottom tabs */
.tabs {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 20;
  display: grid; grid-template-columns: repeat(5, 1fr);
  padding-bottom: env(safe-area-inset-bottom, 0px);
  padding-left: env(safe-area-inset-left, 0px); padding-right: env(safe-area-inset-right, 0px);
  background: color-mix(in srgb, var(--surface) 92%, transparent);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  border-top: 1px solid var(--line);
}
.tab { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 2px; height: var(--tabs-h);
  color: var(--muted); text-decoration: none; font: 600 11px/1 var(--sans); letter-spacing: 0.04em; }
.tab.on { color: var(--accent); }
@media (min-width: 900px) {
  .tabs { left: 50%; right: auto; bottom: 16px; transform: translateX(-50%); width: 460px; border: 1px solid var(--line); border-radius: 18px; padding: 0; }
}

/* ---------- page column */
.wrap {
  max-width: calc(var(--col) + 32px); margin: 0 auto;
  padding-left: max(16px, env(safe-area-inset-left, 0px)); padding-right: max(16px, env(safe-area-inset-right, 0px));
  padding-block: 20px 8px;
  display: flex; flex-direction: column; gap: 20px;
}
h1, h2, h3, h4 { font-family: var(--sans); line-height: 1.2; text-wrap: balance; margin: 0; letter-spacing: -0.01em; }
h1 { font-size: clamp(1.9rem, 1.2rem + 3vw, 2.6rem); font-weight: 700; }
h2 { font-size: 1.3rem; font-weight: 700; }
h3 { font-size: 1.08rem; font-weight: 650; }
p { margin: 0; }
.eyebrow { font: 600 12px/1.2 var(--sans); letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted); margin: 0; }
.lede { font-size: 1.05em; color: var(--muted); }
.hint { font: 500 14px/1.5 var(--sans); color: var(--muted); }
.stats { font: 500 14px/1.4 var(--sans); color: var(--muted); font-variant-numeric: tabular-nums; }
.stats strong { color: var(--ink); }

/* ---------- buttons, fields, chips */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 44px; padding: 0 18px;
  border-radius: 12px; border: 1px solid var(--line); background: var(--surface); color: var(--ink);
  font: 600 15px/1 var(--sans); text-decoration: none; cursor: pointer; }
.btn:hover { border-color: var(--accent); }
.btn.small { min-height: 38px; padding: 0 14px; font-size: 14px; }
.btn.ghost { background: transparent; }
.btn.primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.btn.good { background: var(--good-soft); color: var(--good); border-color: transparent; }
.btn.again { background: var(--bad-soft); color: var(--bad); border-color: transparent; }
.btn.danger { color: var(--bad); }
.field { width: 100%; min-height: 44px; padding: 8px 12px; border-radius: 12px; border: 1px solid var(--line);
  background: var(--surface); color: var(--ink); font: 500 16px/1.4 var(--sans); }
.field.big { min-height: 52px; font-size: 17px; }
.field.mono { font: 13px/1.5 var(--mono); }
select.field { width: auto; flex: 1 1 10rem; }
.row { display: flex; flex-wrap: wrap; gap: 8px; }
.chip, .badge { display: inline-flex; align-items: center; height: 26px; padding: 0 10px; border-radius: 999px;
  font: 600 12.5px/1 var(--sans); background: var(--sunken); color: var(--muted); white-space: nowrap; font-variant-numeric: tabular-nums; }
.badge.deep { background: var(--deep-soft); color: var(--deep); }
.badge.skim { background: var(--sunken); color: var(--muted); }

/* ---------- cards */
.card { display: flex; flex-direction: column; gap: 6px; padding: 16px; border-radius: 16px; background: var(--surface);
  border: 1px solid var(--line); color: var(--ink); font: 500 15px/1.45 var(--sans); }
.card.link { text-decoration: none; }
.card.link:hover { border-color: var(--accent); }
.card strong { font-size: 17px; }
.card > span:not(.eyebrow):not(.stats) { color: var(--muted); }
.card .ico { color: var(--accent); width: 24px; height: 24px; }
.card.stack { gap: 12px; }
.grid2, .grid3 { display: grid; gap: 12px; }
@media (min-width: 620px) { .grid2 { grid-template-columns: 1fr 1fr; } .grid3 { grid-template-columns: repeat(3, 1fr); } }

/* ---------- home */
.hero { display: flex; flex-direction: column; gap: 12px; padding-top: 8px; }
.strip { display: flex; align-items: flex-end; gap: 2px; height: 44px; padding: 6px 0; }
.strip i { flex: 1 1 0; min-width: 0; height: 45%; border-radius: 2px; background: var(--line); transition: background 200ms; }
.strip i.deep { height: 100%; }
.strip i.is-read.asr { background: var(--accent); }
.strip i.is-read.tts { background: var(--deep); }
.continue .continue-title { font: 700 20px/1.25 var(--sans); text-decoration: none; color: var(--ink); }
.continue .continue-title::after { content: " →"; color: var(--accent); }
.continue-meta { color: var(--muted); }
.mini { margin: 0; padding: 0; list-style: none; display: flex; flex-direction: column; gap: 4px; }
.mini a { text-decoration: none; }
.mini a.is-read { color: var(--muted); text-decoration: line-through; }
.offline { background: var(--sunken); border-style: dashed; }
.install summary { cursor: pointer; color: var(--accent); font-weight: 600; margin-top: 4px; }
.install p { margin-top: 6px; color: var(--muted); }

/* ---------- track and plan lists */
.track-head { display: flex; flex-direction: column; gap: 10px; }
.map { background: var(--surface); border: 1px solid var(--line); border-radius: 16px; padding: 4px 16px 16px; }
.map > summary { font: 650 16px/1.3 var(--sans); padding: 12px 0; cursor: pointer; }
.map > *:not(summary) + * { margin-top: 12px; }
.phase { display: flex; flex-direction: column; gap: 8px; padding-top: 8px; }
.phase .intro { color: var(--muted); font-size: 0.95em; }
.plist { list-style: none; margin: 4px 0 0; padding: 0; display: flex; flex-direction: column; border-top: 1px solid var(--line); }
.plist li { border-bottom: 1px solid var(--line); }
.plist li.empty { padding: 12px 0; color: var(--muted); font: 500 14px var(--sans); }
.prow { display: grid; grid-template-columns: 2.2rem 1fr auto 18px; align-items: center; gap: 10px; padding: 12px 0;
  text-decoration: none; color: var(--ink); font-family: var(--sans); }
.pnum { font: 500 13px/1 var(--mono); color: var(--muted); }
.pmain { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.pshort { font-weight: 650; font-size: 16px; line-height: 1.3; }
.pmeta { font-size: 13px; color: var(--muted); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.pside { display: flex; flex-direction: column; align-items: flex-end; gap: 4px; }
.mins, .day { font: 500 12px/1 var(--sans); color: var(--muted); font-variant-numeric: tabular-nums; }
.tick { width: 18px; height: 18px; border-radius: 50%; border: 1.5px solid var(--line); }
.prow.is-read .tick { border-color: var(--good); background: var(--good); box-shadow: inset 0 0 0 3px var(--surface); }
.prow.is-read .pshort { color: var(--muted); }
.dayblock { display: flex; flex-direction: column; gap: 6px; padding-top: 6px; }
.dayhead { display: flex; flex-wrap: wrap; align-items: baseline; gap: 6px 12px; }
.daymeta { font: 500 13px/1.3 var(--sans); color: var(--muted); }
.today-pill { font: 700 11px/1 var(--sans); letter-spacing: 0.1em; text-transform: uppercase; background: var(--accent); color: var(--accent-ink); padding: 5px 8px; border-radius: 6px; }
.dayblock.is-today h2 { color: var(--accent); }
.dayblock .btn { align-self: flex-start; margin-top: 6px; }
.plan-start { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; font: 600 15px var(--sans); }
.plan-start .field { width: auto; }

/* ---------- paper page */
.paper { display: flex; flex-direction: column; gap: 14px; }
.crumbs { font: 500 13.5px/1.4 var(--sans); color: var(--muted); }
.crumbs a { color: var(--muted); }
.fulltitle { font-style: italic; color: var(--muted); font-size: 0.95em; line-height: 1.45; }
.byline { font: 500 14px/1.4 var(--sans); color: var(--muted); }
.facts { display: flex; flex-wrap: wrap; gap: 6px; }
.toc { position: sticky; top: calc(52px + env(safe-area-inset-top, 0px)); z-index: 10;
  display: flex; gap: 6px; overflow-x: auto; scrollbar-width: none; padding: 8px 0;
  margin-left: -16px; margin-right: -16px; padding-left: 16px; padding-right: 16px;
  background: var(--bg); border-bottom: 1px solid var(--line); }
.toc::-webkit-scrollbar { display: none; }
.toc a { flex: none; font: 600 13px/1 var(--sans); padding: 8px 12px; border-radius: 999px; background: var(--sunken); color: var(--muted); text-decoration: none; }
.toc a.on { background: var(--accent-soft); color: var(--accent); }
.sec { display: flex; flex-direction: column; gap: 14px; padding-top: 18px; }
.sec > h2 { font-size: 1.2rem; display: flex; align-items: center; gap: 10px; }
.sec > h2::before { content: ""; width: 6px; height: 1.1em; border-radius: 3px; background: var(--accent); flex: none; }
.sec.gist { background: var(--accent-soft); border-radius: 16px; padding: 16px; margin-top: 12px; }
.sec.gist > h2 { font-size: 0.8rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent); }
.sec.gist > h2::before { display: none; }
.sec.gist p { font-size: 1.08em; line-height: 1.55; }
.sec h3 { margin-top: 6px; }
.sec ul, .sec ol { margin: 0; padding-left: 1.3em; display: flex; flex-direction: column; gap: 6px; }
.sec li > ul, .sec li > ol { margin-top: 6px; }
.sec li::marker { color: var(--muted); }
code { font: 0.84em/1.4 var(--mono); background: var(--code-bg); padding: 0.1em 0.35em; border-radius: 5px; overflow-wrap: anywhere; }
.code { overflow-x: auto; background: var(--code-bg); border-radius: 12px; border: 1px solid var(--line); }
.code pre { margin: 0; padding: 14px; font: 13px/1.5 var(--mono); }
.code code { background: none; padding: 0; font-size: inherit; overflow-wrap: normal; }
.table { overflow-x: auto; border: 1px solid var(--line); border-radius: 12px; }
table { border-collapse: collapse; width: 100%; font: 14px/1.45 var(--sans); }
th, td { text-align: left; vertical-align: top; padding: 9px 12px; border-bottom: 1px solid var(--line); min-width: 7rem; }
th { background: var(--sunken); font-weight: 650; }
tr:last-child td { border-bottom: 0; }
blockquote { margin: 0; padding: 12px 16px; border-left: 3px solid var(--line); color: var(--ink); }
blockquote.analogy { border-left-color: var(--deep); background: var(--deep-soft); border-radius: 0 12px 12px 0; }
blockquote > * + * { margin-top: 8px; }
.xref { font-family: var(--sans); font-weight: 600; font-size: 0.92em; text-decoration: none; border-bottom: 1px dotted var(--accent); }
.xref.is-read::after { content: " ✓"; color: var(--good); }
.xref.missing { color: var(--muted); border-bottom: 0; }

.quiz { display: flex; flex-direction: column; gap: 8px; }
.qa { background: var(--surface); border: 1px solid var(--line); border-radius: 14px; }
.qa summary { list-style: none; display: grid; grid-template-columns: auto 1fr; gap: 10px; padding: 14px; cursor: pointer; font: 600 16px/1.4 var(--sans); }
.qa summary::-webkit-details-marker { display: none; }
.qa .qn { font: 600 12px/1.6 var(--mono); color: var(--accent); }
.qa .ans { padding: 0 14px 14px; display: flex; flex-direction: column; gap: 10px; border-top: 1px dashed var(--line); padding-top: 12px; margin: 0 14px; padding-left: 0; padding-right: 0; }
.qa[open] { border-color: var(--accent); }
.reveal-all { align-self: flex-start; background: none; border: 0; padding: 4px 0; color: var(--accent); font: 600 14px var(--sans); cursor: pointer; }

.paper-links { display: flex; flex-wrap: wrap; gap: 8px; padding-top: 12px; }
.done-row { display: flex; padding-top: 4px; }
.done-row .btn { flex: 1; }
.when-read { display: none; }
[data-mark].is-read { background: var(--good-soft); color: var(--good); border-color: transparent; }
[data-mark].is-read .when-read { display: inline; }
[data-mark].is-read .when-unread { display: none; }
.prevnext { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.pn { display: flex; flex-direction: column; gap: 4px; padding: 14px; border-radius: 14px; border: 1px solid var(--line); text-decoration: none; min-width: 0; }
.pn.next { text-align: right; }
.pn.empty { border: 0; }
.pn-l { font: 600 12px/1.2 var(--sans); color: var(--muted); letter-spacing: 0.04em; }
.pn-t { font: 650 15px/1.3 var(--sans); color: var(--ink); overflow-wrap: anywhere; }
.resume .btn { width: 100%; }

/* ---------- glossary */
.jump { display: flex; flex-wrap: wrap; gap: 4px; }
.jump a { display: grid; place-items: center; min-width: 34px; height: 34px; border-radius: 8px; background: var(--sunken); text-decoration: none; font: 600 14px var(--sans); }
.glossary { margin: 0; display: flex; flex-direction: column; gap: 4px; }
.gl-letter { padding-top: 14px; color: var(--accent); }
.term { padding: 10px 0; border-bottom: 1px solid var(--line); }
.term dt { font: 650 16px/1.3 var(--sans); }
.term dd { margin: 4px 0 0; }
.term:target { background: var(--accent-soft); border-radius: 10px; padding: 10px; }

/* ---------- review */
.filters { display: flex; flex-wrap: wrap; gap: 8px; }
.flash { display: flex; flex-direction: column; gap: 16px; padding: 20px 18px; border-radius: 18px; background: var(--surface); border: 1px solid var(--line); min-height: 16rem; }
.flash-paper { font: 600 13px/1.3 var(--sans); text-decoration: none; }
.flash-q { font: 650 1.2rem/1.4 var(--sans); }
.flash-a { display: flex; flex-direction: column; gap: 10px; border-top: 1px dashed var(--line); padding-top: 14px; }
.flash-a ul, .flash-a ol { margin: 0; padding-left: 1.3em; }
.flash-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: auto; }
.flash-actions [data-flash-show] { grid-column: 1 / -1; }
.empty-state { align-items: flex-start; }

/* ---------- search */
.results { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; }
.results li { border-bottom: 1px solid var(--line); }
.results a { display: flex; flex-direction: column; gap: 3px; padding: 12px 0; text-decoration: none; color: var(--ink); }
.results .r-t { font: 650 16px/1.3 var(--sans); }
.results .r-k { font: 500 12.5px/1.3 var(--sans); color: var(--muted); }
.results .r-x { font-size: 15px; color: var(--muted); }
mark { background: var(--mark); color: inherit; border-radius: 3px; padding: 0 2px; }

/* ---------- settings */
.seg { display: flex; flex-wrap: wrap; gap: 6px; }
.seg label { display: inline-flex; align-items: center; gap: 6px; padding: 8px 12px; border-radius: 10px; background: var(--sunken); font: 600 14px var(--sans); cursor: pointer; }
input[type="range"] { width: 100%; accent-color: var(--accent); }