/* app.css — the whole visual system for duo.raku.online.
   One stylesheet, no build step, no framework. */

:root {
  --bg: #fbfaf7;
  --bg-sunk: #f3f1eb;
  --panel: #ffffff;
  --ink: #23201c;
  --ink-soft: #5d574e;
  --ink-faint: #8b8377;
  --rule: #e2ddd2;
  --rule-soft: #eeeae1;
  --accent: #9c4221;
  --accent-soft: #f6e9e1;
  --target-tint: #fdf6ec;
  --hi: #ffeaa7;
  --hi-strong: #ffd76e;
  --ok: #2f6f4f;
  --code-bg: #f4f2ec;
  --shadow: 0 6px 24px rgba(35, 32, 28, .10);
  --radius: 10px;
  --prose: 1.02rem;
  --measure: 38rem;
}

:root[data-theme-active="dark"] {
  --bg: #16181c;
  --bg-sunk: #1d2026;
  --panel: #1f2229;
  --ink: #e5e3de;
  --ink-soft: #a8a49c;
  --ink-faint: #7c7871;
  --rule: #31353d;
  --rule-soft: #262a31;
  --accent: #e08b5f;
  --accent-soft: #2c2118;
  --target-tint: #1b1e24;
  --hi: #4a4126;
  --hi-strong: #6b5b2b;
  --ok: #6bbf92;
  --code-bg: #14161a;
  --shadow: 0 6px 24px rgba(0, 0, 0, .4);
}

* { box-sizing: border-box; }

/* A `display` in a class rule outranks the browser's rule for [hidden], and
   most things here are grid or flex. Say it once, loudly. */
[hidden] { display: none !important; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.65 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  padding-top: 3.25rem;
}

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { text-decoration-style: solid; }

/* ---------------------------------------------------------------- the bar */

.bar {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 40;
  height: 3.25rem;
  display: flex;
  align-items: center;
  gap: .75rem;
  padding: 0 .9rem;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(1.6) blur(10px);
  border-bottom: 1px solid var(--rule);
}

.bar-home {
  font-size: 1.15rem;
  text-decoration: none;
  color: var(--ink-soft);
  flex: none;
}
.bar-home:hover { color: var(--accent); }
.bar-home.is-here { color: var(--accent); }

.crumbs {
  flex: 1 1 auto;
  min-width: 0;
  font-size: .82rem;
  color: var(--ink-faint);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.crumbs a { color: var(--ink-soft); text-decoration: none; }
.crumbs a:hover { color: var(--accent); text-decoration: underline; }
.crumbs .sep { opacity: .5; padding: 0 .35rem; }

.bar-tools { display: flex; align-items: center; gap: .35rem; flex: none; }

.tool {
  border: 1px solid transparent;
  background: none;
  color: var(--ink-soft);
  font: inherit;
  font-size: .95rem;
  line-height: 1;
  padding: .4rem .5rem;
  border-radius: 7px;
  cursor: pointer;
  text-decoration: none;
}
.tool:hover { background: var(--bg-sunk); color: var(--ink); }
.tool.is-on { background: var(--accent-soft); color: var(--accent); border-color: var(--rule); }

/* --------------------------------------------------------- language pair */

.pair { display: flex; align-items: center; gap: .3rem; }

.pair select {
  font: inherit;
  font-size: .82rem;
  padding: .28rem 1.3rem .28rem .45rem;
  border: 1px solid var(--rule);
  border-radius: 7px;
  background: var(--panel) url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 10 6'><path d='M1 1l4 4 4-4' fill='none' stroke='%23888' stroke-width='1.5'/></svg>") no-repeat right .4rem center;
  background-size: .55rem;
  color: var(--ink);
  appearance: none;
  cursor: pointer;
}
.pair select.is-target { border-color: var(--accent); color: var(--accent); font-weight: 600; }
.pair .swap {
  border: none; background: none; cursor: pointer;
  color: var(--ink-faint); font-size: .95rem; padding: .2rem .1rem;
}
.pair .swap:hover { color: var(--accent); }

.pair-big { justify-content: center; gap: .5rem; margin: 1.6rem 0 .6rem; }
.pair-big select { font-size: 1.05rem; padding: .6rem 2rem .6rem .8rem; max-width: none; background-size: .7rem; }
.pair-big .swap { font-size: 1.3rem; }

/* ------------------------------------------------------------ the reader */

.reader {
  max-width: 82rem;
  margin: 0 auto;
  padding: 1.6rem 1.2rem 2rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  column-gap: 2.4rem;
  row-gap: .2rem;
  align-items: start;
}

.pr { display: contents; }

.cell {
  min-width: 0;
  padding: .35rem .55rem;
  border-radius: 8px;
  position: relative;
}
.cell-target { background: var(--target-tint); }

/* A cell with nothing in it still holds its place in the grid — otherwise the
   rows below would slide up out of alignment — but it must not look like an
   empty box someone forgot to fill. */
.cell.is-empty { background: none; padding: 0; }

/* An example that is identical in both languages is one example, not two. */
.pr.same-code .cell-base { grid-column: 1 / -1; }
.pr.same-code .cell-target { display: none; }

.cell > :first-child { margin-top: 0; }
.cell > :last-child { margin-bottom: 0; }

.cell p, .cell li, .cell blockquote, .cell td {
  font-size: var(--prose);
  line-height: 1.7;
}
.cell p { margin: .5rem 0; }
.cell h2, .cell h3, .cell h4 {
  margin: .4rem 0 .3rem;
  font-size: 1.12rem;
  line-height: 1.35;
  letter-spacing: -.01em;
}
.cell blockquote {
  margin: .5rem 0;
  padding-left: .9rem;
  border-left: 3px solid var(--rule);
  color: var(--ink-soft);
}
.cell ul, .cell ol { margin: .5rem 0; padding-left: 1.3rem; }
.cell li { margin: .2rem 0; }
.cell table { border-collapse: collapse; width: 100%; font-size: .95rem; }
.cell td { border-bottom: 1px solid var(--rule-soft); padding: .3rem .5rem; vertical-align: top; }

/* Quizzes are here to be read, not answered — the course itself does the
   answering. The right options are marked so the page still teaches. */
.cell ul.quiz { list-style: none; padding-left: 0; }
.cell .quiz-opt { position: relative; padding-left: 1.35rem; margin: .25rem 0; }
.cell .quiz-opt::before {
  content: "○";
  position: absolute; left: 0; top: 0;
  color: var(--ink-faint);
  font-size: .85em;
}
.cell .quiz-opt.is-right::before { content: "●"; color: var(--ok); }
.cell .quiz-note {
  display: block;
  font-size: .88em;
  color: var(--ink-soft);
  margin-top: .1rem;
}

.cell code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: .88em;
  background: var(--code-bg);
  padding: .1em .3em;
  border-radius: 4px;
}
.cell pre {
  margin: .5rem 0;
  padding: .7rem .85rem;
  background: var(--code-bg);
  border: 1px solid var(--rule-soft);
  border-radius: 8px;
  overflow-x: auto;
}
.cell pre code { background: none; padding: 0; font-size: .84rem; line-height: 1.55; }

/* The page title, spanning both columns, in both languages. */
.page-head { grid-column: 1 / -1; margin: 0 0 1.1rem; }
.page-head h1 {
  margin: 0;
  font-size: 1.55rem;
  line-height: 1.2;
  letter-spacing: -.02em;
}
.page-head .h-target { color: var(--accent); }
.page-head .h-sep { color: var(--ink-faint); font-weight: 400; padding: 0 .5rem; }
.page-head .srcs { margin-top: .45rem; font-size: .78rem; color: var(--ink-faint); }
.page-head .srcs .off { color: var(--ink-faint); opacity: .5; }
.page-head .kicker {
  display: block;
  font-size: .72rem;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--ink-faint);
  margin-bottom: .35rem;
}

.children { grid-column: 1 / -1; max-width: var(--measure); }
.children .toc-list a { font-size: .95rem; padding: .25rem .3rem; }

/* --------------------------------------------------- alignment machinery */

.sg { border-radius: 3px; transition: background-color .12s; }
.sg.hi { background: var(--hi); }
.pr.hi .cell { box-shadow: inset 2px 0 0 var(--accent); }
.sg.spoken { background: var(--hi-strong); }

/* A block whose two languages disagree on how many sentences they have: pair
   the paragraph, not the sentence, and say so rather than mis-highlighting. */
.pr.no-sync .cell-target::after {
  content: "≠";
  position: absolute;
  top: .3rem; right: .35rem;
  font-size: .7rem;
  color: var(--ink-faint);
  opacity: .5;
}

.cell-target .sg { cursor: text; }

.blk-tools {
  position: absolute;
  top: .1rem; right: .2rem;
  display: flex; gap: .1rem;
  opacity: 0;
  transition: opacity .12s;
}
.cell:hover .blk-tools, .blk-tools:focus-within { opacity: 1; }
.blk-tools button {
  border: none; background: var(--panel); color: var(--ink-faint);
  border: 1px solid var(--rule); border-radius: 5px;
  font-size: .7rem; line-height: 1; padding: .2rem .3rem; cursor: pointer;
}
.blk-tools button:hover { color: var(--accent); border-color: var(--accent); }

/* ------------------------------------------------------- reading  modes */

/* One column: the target on top, the base underneath and out of the way. */
:root[data-mode="target"] .reader,
:root[data-mode="base"] .reader { grid-template-columns: minmax(0, var(--measure)); justify-content: center; }
:root[data-mode="target"] .pr,
:root[data-mode="base"] .pr { display: flex; flex-direction: column; gap: .15rem; }

:root[data-mode="target"] .cell-base,
:root[data-mode="base"] .cell-target { order: 2; }
:root[data-mode="target"] .cell-target,
:root[data-mode="base"] .cell-base { order: 1; }

/* The hidden half stays in the DOM — it is one click from being needed. */
:root[data-mode="target"] .pr:not(.shown) .cell-base,
:root[data-mode="base"] .pr:not(.shown) .cell-target {
  height: .55rem;
  overflow: hidden;
  padding: 0;
  background: repeating-linear-gradient(-45deg, var(--rule-soft) 0 5px, transparent 5px 10px);
  border-radius: 3px;
  cursor: pointer;
  opacity: .8;
}
:root[data-mode="target"] .pr:not(.shown) .cell-base > *,
:root[data-mode="base"] .pr:not(.shown) .cell-target > * { display: none; }

:root[data-mode="target"] .pr.shown .cell-base,
:root[data-mode="base"] .pr.shown .cell-target {
  border-left: 2px solid var(--rule);
  border-radius: 0 8px 8px 0;
  color: var(--ink-soft);
}

:root[data-code="hide"] .cell pre { display: none; }
:root[data-code="hide"] .pr.only-code { display: none; }

/* ------------------------------------------------------------- the pager */

.pager {
  max-width: 82rem;
  margin: 0 auto;
  padding: 1rem 1.2rem 4rem;
  display: flex;
  gap: .8rem;
  align-items: stretch;
  border-top: 1px solid var(--rule-soft);
}
.pager a {
  flex: 1 1 0;
  min-width: 0;
  text-decoration: none;
  color: inherit;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: .7rem .9rem;
  background: var(--panel);
  display: block;
}
.pager a:hover { border-color: var(--accent); }
.pager .dir { display: block; font-size: .7rem; text-transform: uppercase; letter-spacing: .09em; color: var(--ink-faint); }
.pager .t-base { display: block; font-size: .92rem; }
.pager .t-target { display: block; font-size: .92rem; color: var(--accent); }
.pager .to-next { text-align: right; }

/* -------------------------------------------------- the drawer and panel */

.drawer, .panel {
  position: fixed;
  top: 3.25rem;
  bottom: 0;
  width: min(30rem, 92vw);
  background: var(--panel);
  border-left: 1px solid var(--rule);
  box-shadow: var(--shadow);
  overflow-y: auto;
  z-index: 45;
  padding: 1rem 1.1rem 3rem;
}
.drawer { right: 0; }

/* The word panel is a bottom sheet, not a side panel: it must never cover the
   column you are reading. */
.panel {
  right: auto;
  left: 50%;
  transform: translateX(-50%);
  top: auto;
  bottom: 0;
  width: min(78rem, 96vw);
  height: min(46vh, 26rem);
  border: 1px solid var(--rule);
  border-bottom: none;
  border-radius: var(--radius) var(--radius) 0 0;
  padding: 1rem 1.4rem 1.4rem;
}
.panel[hidden], .drawer[hidden] { display: none; }

/* Two columns of examples when there is room for them. */
@media (min-width: 60rem) {
  .panel { column-count: 2; column-gap: 2.4rem; }
  .panel .wp-head, .panel .wp-acts, .panel .wp-sent { column-span: all; }
}

.drawer h2, .panel h2 { margin: 0 0 .6rem; font-size: 1rem; }
.drawer .close, .panel .close {
  position: absolute; top: .5rem; right: .7rem;
  border: none; background: none; color: var(--ink-faint);
  font-size: 1.1rem; cursor: pointer;
}

.toc-part { margin: 0 0 1.1rem; }
.toc-part > a { display: block; font-weight: 650; text-decoration: none; color: var(--ink); padding: .2rem 0; }
.toc-group { font-size: .72rem; text-transform: uppercase; letter-spacing: .09em; color: var(--ink-faint); margin: .6rem 0 .15rem; }
.toc-list { list-style: none; margin: 0; padding: 0 0 0 .2rem; }
.toc-list a {
  display: block;
  text-decoration: none;
  color: var(--ink-soft);
  font-size: .88rem;
  padding: .14rem .3rem;
  border-radius: 5px;
  border-left: 2px solid transparent;
}
.toc-list a:hover { background: var(--bg-sunk); color: var(--ink); }
.toc-list a.is-here { border-left-color: var(--accent); color: var(--accent); background: var(--accent-soft); }
.toc-list a.is-read::after { content: " ✓"; color: var(--ok); font-size: .8em; }
.toc-list .t2 { padding-left: 1rem; }
.toc-list .t3 { padding-left: 2rem; font-size: .84rem; }
.toc-list .lang2 { color: var(--ink-faint); font-size: .92em; }

/* ------------------------------------------------------- the word  panel */

.wp-head { display: flex; align-items: baseline; gap: .6rem; flex-wrap: wrap; margin-bottom: .2rem; }
.wp-word { font-size: 1.5rem; font-weight: 650; letter-spacing: -.01em; }
.wp-meta { font-size: .78rem; color: var(--ink-faint); }
.wp-acts { display: flex; gap: .4rem; margin: .6rem 0 .9rem; flex-wrap: wrap; }

.btn {
  font: inherit; font-size: .84rem;
  border: 1px solid var(--rule);
  background: var(--panel);
  color: var(--ink);
  padding: .35rem .7rem;
  border-radius: 7px;
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
}
.btn:hover { border-color: var(--accent); color: var(--accent); }
.btn.is-on { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn-quiet { color: var(--ink-faint); }

.wp-sent { border-left: 3px solid var(--accent); padding: .1rem 0 .1rem .7rem; margin: .5rem 0 .9rem; }
.wp-sent .t { display: block; }
.wp-sent .b { display: block; color: var(--ink-soft); font-size: .93em; margin-top: .15rem; }
.wp-sent mark { background: var(--hi); color: inherit; border-radius: 3px; padding: 0 .1em; }

.wp-more { font-size: .72rem; text-transform: uppercase; letter-spacing: .09em; color: var(--ink-faint); margin: 1rem 0 .3rem; }
.wp-ex { border-top: 1px solid var(--rule-soft); padding: .5rem 0; font-size: .93rem; }
.wp-ex .t { display: block; }
.wp-ex .b { display: block; color: var(--ink-soft); font-size: .92em; }
.wp-ex .src { font-size: .74rem; }
.wp-ex mark { background: var(--hi); color: inherit; border-radius: 3px; padding: 0 .1em; }

/* --------------------------------------------------------- the home page */

/* Wide enough for three columns of contents; the reading matter inside keeps
   its own, narrower measure. */
.home { max-width: 76rem; margin: 0 auto; padding: 2rem 1.2rem 5rem; }
.hero { max-width: 46rem; }
.hero h1 { font-size: 2.1rem; line-height: 1.12; letter-spacing: -.025em; margin: .2rem 0 .5rem; }
.lede { font-size: 1.05rem; color: var(--ink-soft); max-width: 34rem; }
.resume { margin: .3rem 0 0; font-size: .9rem; }

/* Six cards, so three across and two down — auto-fit would leave an orphan on
   a wide window. */
.how { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: .9rem; margin: 2.2rem 0; }
.how div { border: 1px solid var(--rule); border-radius: var(--radius); padding: .8rem .9rem; background: var(--panel); }
.how h3 { margin: 0 0 .25rem; font-size: .92rem; }
.how p { margin: 0; font-size: .85rem; color: var(--ink-soft); }
.how kbd {
  font: inherit; font-size: .78em;
  border: 1px solid var(--rule); border-bottom-width: 2px;
  border-radius: 4px; padding: 0 .3em; background: var(--bg-sunk);
}

.contents h2 { font-size: 1.1rem; margin: 2rem 0 .3rem; }
.contents .note { font-size: .85rem; color: var(--ink-faint); margin: 0 0 1.2rem; }

/* Three columns, dropping to two and then one as the window narrows.
   The parts are wildly uneven — 41 sections in one, none in another — so the
   unbreakable unit is the group, not the part: fine-grained enough for the
   browser to balance the columns, coarse enough that a heading never parts
   company with its list. */
.home-toc { columns: 3 17rem; column-gap: 2.6rem; }
.home-toc .toc-grp { break-inside: avoid; }
.home-toc .toc-part { margin-bottom: 1.4rem; }
.home-toc .toc-part > a { break-after: avoid; font-size: 1.02rem; }
.home-toc .toc-list a { padding: .16rem .3rem; }
.home-toc .n { color: var(--ink-faint); font-size: .76em; vertical-align: .35em; }

/* -------------------------------------------------------- the words page */

.words { max-width: 54rem; margin: 0 auto; padding: 1.6rem 1.2rem 5rem; }
.words-head { display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-wrap: wrap; margin-bottom: 1rem; }
.words-count { font-size: .88rem; color: var(--ink-soft); }
.words-acts { display: flex; gap: .4rem; flex-wrap: wrap; }

.word-list { display: grid; gap: .5rem; }
.wcard {
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: .6rem .8rem;
  background: var(--panel);
}
.wcard .top { display: flex; align-items: baseline; gap: .5rem; }
.wcard .w { font-weight: 650; font-size: 1.05rem; }
.wcard .lg { font-size: .7rem; text-transform: uppercase; letter-spacing: .08em; color: var(--ink-faint); }
.wcard .box { margin-left: auto; font-size: .72rem; color: var(--ink-faint); }
.wcard .s { font-size: .9rem; margin-top: .2rem; }
.wcard .s .b { display: block; color: var(--ink-soft); font-size: .93em; }
.wcard mark { background: var(--hi); color: inherit; border-radius: 3px; }
.wcard .drop { border: none; background: none; color: var(--ink-faint); cursor: pointer; font-size: .95rem; }
.wcard .drop:hover { color: var(--accent); }

.drill { border: 1px solid var(--rule); border-radius: var(--radius); padding: 1.4rem; background: var(--panel); text-align: center; }
.drill .prompt { font-size: 1.2rem; line-height: 1.6; margin: .5rem 0 1rem; }
.drill .prompt .gap { display: inline-block; min-width: 4rem; border-bottom: 2px solid var(--accent); }
.drill .answer { font-size: 1.4rem; font-weight: 650; color: var(--accent); margin: .4rem 0; }
.drill .hint { color: var(--ink-soft); font-size: .95rem; }
.drill .acts { display: flex; gap: .5rem; justify-content: center; margin-top: 1rem; flex-wrap: wrap; }
.drill .progress { font-size: .78rem; color: var(--ink-faint); }

/* ------------------------------------------------------------- the toast */

.toasts { position: fixed; bottom: 1rem; left: 50%; transform: translateX(-50%); z-index: 60; display: grid; gap: .4rem; }
.toast {
  background: var(--ink); color: var(--bg);
  padding: .45rem .9rem; border-radius: 999px;
  font-size: .85rem; box-shadow: var(--shadow);
  animation: pop .2s ease-out;
}
@keyframes pop { from { opacity: 0; transform: translateY(6px); } }

/* ------------------------------------------------------------- the  help */

.help { position: fixed; inset: 0; z-index: 70; background: rgba(0,0,0,.45); display: grid; place-items: center; padding: 1rem; }
.help[hidden] { display: none; }
.help-box { background: var(--panel); border-radius: var(--radius); padding: 1.3rem 1.5rem; max-width: 30rem; width: 100%; box-shadow: var(--shadow); }
.help-box h2 { margin: 0 0 .7rem; font-size: 1.05rem; }
.help-box dl { display: grid; grid-template-columns: auto 1fr; gap: .3rem .9rem; margin: 0; font-size: .88rem; }
.help-box dt { text-align: right; }
.help-box kbd {
  font: inherit; font-size: .82em;
  border: 1px solid var(--rule); border-bottom-width: 2px;
  border-radius: 4px; padding: 0 .35em; background: var(--bg-sunk);
}
.help-box dd { margin: 0; color: var(--ink-soft); }

/* ------------------------------------------------------------ small nav */

@media (max-width: 860px) {
  body { padding-top: 6rem; }
  .bar { height: auto; flex-wrap: wrap; padding: .4rem .7rem; row-gap: .35rem; }
  .crumbs { order: 3; flex-basis: 100%; }
  .reader { grid-template-columns: minmax(0, 1fr); row-gap: .1rem; }
  .pr { display: flex; flex-direction: column; gap: .1rem; }
  .cell-base { order: 2; }
  .cell-target { order: 1; }
  .home-toc { columns: 1; }
  .how { grid-template-columns: 1fr; }
  .drawer, .panel { top: auto; height: 78vh; width: 100vw; border-radius: var(--radius) var(--radius) 0 0; }
}

@media print {
  .bar, .pager, .drawer, .panel, .toasts, .blk-tools { display: none; }
  body { padding-top: 0; }
}