:root {
  --paper: #f3f5f8;
  --surface: #ffffff;
  --ink: #1b2233;
  --muted: #586275;
  --line: #d8dde6;
  --g: #0f766e;        /* -ing */
  --g-soft: #d5f0ec;
  --i: #4f46e5;        /* to + verb */
  --i-soft: #e3e1fc;
  --b: #a15c07;        /* base form */
  --b-soft: #fbe9c9;
  --o: #b8185a;        /* person / object */
  --o-soft: #fbdde8;
  --k-soft: #e6e9ef;
  --right: #0f766e;
  --wrong: #c2261d;
  --display: "Bricolage Grotesque", "Segoe UI", system-ui, sans-serif;
  --body: "Atkinson Hyperlegible", "Segoe UI", system-ui, sans-serif;
  --r-sm: 6px;
  --r-md: 12px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #131826;
    --surface: #1b2133;
    --ink: #e8ebf2;
    --muted: #a3acbf;
    --line: #313a50;
    --g: #4fd1c1; --g-soft: #123a38;
    --i: #a5a0ff; --i-soft: #2a2760;
    --b: #f0b35a; --b-soft: #45320f;
    --o: #f57aa8; --o-soft: #4a1a2e;
    --k-soft: #2a3246;
    --right: #4fd1c1; --wrong: #ff7b72;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #131826; --surface: #1b2133; --ink: #e8ebf2; --muted: #a3acbf; --line: #313a50;
  --g: #4fd1c1; --g-soft: #123a38; --i: #a5a0ff; --i-soft: #2a2760;
  --b: #f0b35a; --b-soft: #45320f; --o: #f57aa8; --o-soft: #4a1a2e; --k-soft: #2a3246;
  --right: #4fd1c1; --wrong: #ff7b72; color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 1.0625rem/1.6 var(--body);
}
h1, h2, h3, h4 { font-family: var(--display); line-height: 1.15; margin: 0 0 .5em; }
h2 { font-size: clamp(1.6rem, 1.2rem + 1.6vw, 2.2rem); font-weight: 800; letter-spacing: -.01em; }
h3 { font-size: 1.3rem; font-weight: 700; margin-top: 0; }
h4 { font-size: 1.05rem; font-weight: 700; margin: 1.2em 0 .4em; }
p { margin: 0 0 .9em; }
a { color: var(--i); text-underline-offset: 3px; }
:focus-visible { outline: 3px solid var(--i); outline-offset: 2px; border-radius: 4px; }
[hidden] { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip { position: absolute; left: 16px; top: -48px; background: var(--ink); color: var(--paper); padding: 8px 12px; border-radius: var(--r-sm); z-index: 10; }
.skip:focus { top: 12px; }

/* Color coding: used everywhere a form is highlighted */
mark { background: none; color: inherit; padding: 0 .15em; border-radius: 3px; font-weight: 700; }
mark.g { background: var(--g-soft); color: var(--g); }
mark.i { background: var(--i-soft); color: var(--i); }
mark.b { background: var(--b-soft); color: var(--b); }
mark.o { background: var(--o-soft); color: var(--o); }
mark.k { background: var(--k-soft); }
.tag { display: inline-block; font-weight: 700; font-size: .85em; padding: 0 .4em; border-radius: 4px; }
.tag.g { background: var(--g-soft); color: var(--g); }
.tag.i { background: var(--i-soft); color: var(--i); }

/* ---------- Hero: the lookup ---------- */
.hero { background: #1b2233; color: #f3f5f8; padding: clamp(40px, 8vw, 88px) 16px clamp(32px, 6vw, 64px); }
.hero-inner { max-width: 880px; margin: 0 auto; }
.hero-top { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-bottom: .6em; }
.series { color: #aeb7cc; margin: 0; }
.theme-btn {
  font: 700 .9rem var(--body); color: #fff; background: none; cursor: pointer;
  border: 1px solid #3b4560; border-radius: 999px; padding: 4px 12px; white-space: nowrap;
}
.theme-btn:hover { border-color: #a5a0ff; }
.hero h1 {
  font-size: clamp(2.4rem, 1.4rem + 5vw, 4.8rem);
  font-weight: 800;
  letter-spacing: -.03em;
  line-height: 1;
  font-variation-settings: "opsz" 96;
  margin-bottom: .35em;
}
.lede { font-size: 1.2rem; max-width: 60ch; }
.hero .tag.g { background: #144b47; color: #7ee6d8; }
.hero .tag.i { background: #2f2b7a; color: #c9c5ff; }
.lookup input {
  width: 100%;
  font: 700 clamp(1.4rem, 1rem + 2vw, 2rem) var(--display);
  padding: .5em .7em;
  border: 2px solid #3b4560;
  border-radius: var(--r-md);
  background: #242c42;
  color: #fff;
}
.lookup input::placeholder { color: #7d88a3; font-weight: 500; }
.lookup input:focus { outline: none; border-color: #a5a0ff; box-shadow: 0 0 0 3px rgba(165,160,255,.35); }
.try { color: #aeb7cc; margin-top: 1em; }
.try button {
  font: inherit; color: #fff; background: none; border: 1px solid #3b4560;
  border-radius: 999px; padding: 2px 12px; margin: 0 2px 6px 0; cursor: pointer;
}
.try button:hover { border-color: #a5a0ff; }
.lookup-result { margin-top: 20px; }
.lookup-result:empty { display: none; }
.hit { background: var(--surface); color: var(--ink); border-radius: var(--r-md); padding: 18px 20px; margin-bottom: 12px; }
.hit .formula { font-size: clamp(1.25rem, 1rem + 1.4vw, 1.8rem); margin-bottom: .5em; }
.hit p { margin-bottom: .4em; }
.hit ul { margin: .4em 0 0; }
.miss { color: #ffd2a8; }
main .miss { color: var(--muted); }

/* Formula strip */
.formula { display: flex; flex-wrap: wrap; align-items: center; gap: .35em; font: 700 1.15rem/1.3 var(--display); margin: 0 0 .7em; }
.formula b { padding: .15em .5em; border-radius: var(--r-sm); background: var(--k-soft); }
.formula b.v { background: var(--ink); color: var(--paper); }
.formula b.g { background: var(--g-soft); color: var(--g); }
.formula b.i { background: var(--i-soft); color: var(--i); }
.formula b.b { background: var(--b-soft); color: var(--b); }
.formula b.o { background: var(--o-soft); color: var(--o); }
.formula em { font-style: normal; color: var(--muted); font-weight: 500; }
.formula b em { color: inherit; }
.plus { color: var(--muted); font-weight: 500; }

/* ---------- Layout ---------- */
.layout { max-width: 1180px; margin: 0 auto; padding: 0 16px; display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 48px; }
.toc { position: sticky; top: 0; align-self: start; padding-top: 48px; }
.toc ol { list-style: none; padding: 0; margin: 0 0 24px; counter-reset: t; }
.toc li { counter-increment: t; }
.toc a {
  display: flex; gap: 10px; padding: 7px 10px; border-radius: var(--r-sm);
  color: var(--muted); text-decoration: none; font-weight: 700;
}
.toc a::before { content: counter(t); font-family: var(--display); color: var(--muted); min-width: 1ch; }
.toc a:hover { color: var(--ink); background: var(--surface); }
.toc a.active { color: var(--ink); background: var(--surface); }
.toc a.active::before { color: var(--i); }
.toc .prog {
  margin-left: auto; align-self: center; white-space: nowrap;
  font: 700 .75rem/1.6 var(--body); color: var(--muted); background: var(--k-soft);
  padding: 0 7px; border-radius: 999px;
}
.toc .prog.done { background: var(--g-soft); color: var(--g); }
.legend { display: grid; gap: 6px; font-size: .9rem; color: var(--muted); padding-left: 10px; }
.sw { display: inline-block; width: 12px; height: 12px; border-radius: 3px; margin-right: 8px; vertical-align: -1px; }
.sw.g { background: var(--g); } .sw.i { background: var(--i); } .sw.b { background: var(--b); } .sw.o { background: var(--o); }

main { padding: 48px 0 32px; min-width: 0; }
.topic { padding-bottom: 56px; margin-bottom: 56px; border-bottom: 1px solid var(--line); scroll-margin-top: 16px; }
.topic:last-child { border-bottom: 0; }
.topic > p, .block > p, .pattern > p { max-width: 72ch; }
.intro { font-size: 1.15rem; color: var(--muted); }
.topic > h3.part { margin-top: 44px; }

.pattern, .block {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  padding: clamp(18px, 3vw, 28px);
  margin-bottom: 20px;
  scroll-margin-top: 16px;
}
.pattern:target { border-color: var(--i); box-shadow: 0 0 0 2px var(--i-soft); }
.pattern > h3 { display: flex; flex-wrap: wrap; align-items: baseline; gap: 4px 14px; }
.pattern > h3 .formula { font-size: 1.35rem; margin: 0; }
.pattern > h3 small { font: 400 1rem var(--body); color: var(--muted); }
h4.label {
  font: 700 .8rem var(--body); text-transform: uppercase; letter-spacing: .06em; color: var(--muted);
  margin: 1.6em 0 .6em;
}
h4.label span { text-transform: none; letter-spacing: 0; font-weight: 400; margin-left: 6px; }

/* Long lists: items with .x stay hidden until the "Show more" button opens the list */
.clip:not(.open) .x { display: none; }
.more-btn {
  font: 700 .95rem var(--body); color: var(--i); background: none; border: 0; cursor: pointer;
  padding: 2px 0; margin: -.3em 0 1em;
}
.more-btn:hover { text-decoration: underline; }
table.clip + .more-btn { margin-top: .6em; }

.chips { display: flex; flex-wrap: wrap; gap: 6px; margin: 0 0 1em; }
.chip { background: var(--paper); border: 1px solid transparent; border-radius: 999px; padding: 1px 11px; font-size: .95rem; }
.chip.tap {
  font: inherit; font-size: .95rem; line-height: 1.6; color: var(--ink); cursor: pointer;
  background: var(--surface); border-color: var(--line);
}
.chip.tap:hover { border-color: var(--i); color: var(--i); }
.chip.tap[aria-expanded="true"] { background: var(--i); border-color: var(--i); color: var(--surface); }
.chip-detail { margin: 0 0 .5em; }
.chip-detail .hit { background: var(--paper); border: 1px solid var(--line); padding: 14px 18px; }
.chip-detail .hit .formula { font-size: 1.15rem; }
.chip-detail .hit ul.ex { margin-bottom: 0; }

ul.ex { padding-left: 1.2em; margin: .6em 0 1em; }
ul.ex li { margin-bottom: .3em; }
ul.plainlist { list-style: none; padding: 0; margin: 0; }
ul.plainlist li { padding: 6px 0; border-bottom: 1px solid var(--line); }

details { margin: .4em 0 1em; }
summary { cursor: pointer; font-weight: 700; color: var(--i); padding: 4px 0; }
details[open] > summary { margin-bottom: .3em; }

.aside { color: var(--muted); font-size: .98rem; }
.note { border-left: 3px solid var(--i); padding: 4px 0 4px 12px; }

table.pairs { width: 100%; border-collapse: collapse; font-size: .98rem; }
.pairs th { text-align: left; font-family: var(--display); color: var(--muted); font-weight: 700; padding: 6px 10px 6px 0; border-bottom: 2px solid var(--line); }
.pairs td { padding: 8px 10px 8px 0; border-bottom: 1px solid var(--line); vertical-align: top; }
.pairs td:first-child { padding-right: 16px; }

/* -ing vs to, one row per verb */
.meaning { margin: 0 0 1em; border-top: 1px solid var(--line); }
.mrow {
  display: grid; grid-template-columns: 120px minmax(0, 1fr) minmax(0, 1fr); gap: 8px 28px;
  padding: 14px 0; border-bottom: 1px solid var(--line);
}
.mrow h4 { margin: 0; font-size: 1.2rem; }
.mrow h4 small { display: block; font-family: var(--body); font-weight: 400; font-size: .75rem; color: var(--muted); }
.mrow p { margin-bottom: .2em; }
.mrow p.s { color: var(--muted); margin: 0; font-size: .95rem; }

/* Homophone cards */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); gap: 10px; margin-bottom: 28px; }
.flip {
  font: inherit; color: inherit; text-align: left; cursor: pointer;
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--r-md);
  padding: 16px; min-height: 120px; display: flex; flex-direction: column; justify-content: center;
}
.flip:hover { border-color: var(--i); }
.flip .front { font: 700 1.35rem/1.2 var(--display); }
.flip .back { display: none; font-size: .92rem; }
.flip .back span { display: block; margin-bottom: 4px; }
.flip .back b { color: var(--i); }
.flip[aria-pressed="true"] { background: var(--i-soft); border-color: var(--i); }
.flip[aria-pressed="true"] .front { display: none; }
.flip[aria-pressed="true"] .back { display: block; }

/* Dialogue */
.dialogue { list-style: none; padding: 0; margin: 0; }
.dialogue li {
  display: grid; grid-template-columns: 90px minmax(0, 1fr) auto; gap: 12px; align-items: start;
  padding: 10px 8px; border-radius: var(--r-sm); border-left: 3px solid transparent;
}
.dialogue li.now { background: var(--i-soft); border-left-color: var(--i); }
.dialogue .who { font-family: var(--display); font-weight: 700; }
.dialogue li.k .who { color: var(--o); }
.dialogue li.l .who { color: var(--i); }
.dialogue p { margin: 0; }
.say {
  font: 700 .85rem var(--body); color: var(--i); background: none; cursor: pointer;
  border: 1px solid var(--line); border-radius: 999px; padding: 2px 10px;
}
.say:hover { border-color: var(--i); }
.speak-row { display: flex; gap: 8px; }

.phrases { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 0 24px; margin: 0; }
.phrases div { padding: 8px 0; border-bottom: 1px solid var(--line); }
.phrases dt { font-weight: 700; }
.phrases dd { margin: 0; color: var(--muted); }

.two { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; margin-bottom: 1em; }
.two h4 { margin-top: 0; }

.timeline { list-style: none; padding: 0; margin: 0 0 1.4em; display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 10px; }
.timeline li { border-top: 3px solid var(--i); padding-top: 8px; font-size: .95rem; }
.timeline b { display: block; font: 800 1.3rem var(--display); }
.reading p { max-width: 68ch; }

/* Buttons & quiz */
.btn {
  font: 700 1rem var(--body); cursor: pointer; border-radius: var(--r-sm);
  padding: 9px 18px; border: 2px solid var(--i); background: var(--i); color: var(--surface);
}
.btn:hover { filter: brightness(1.08); }
.btn.ghost { background: none; color: var(--i); }
.linkish { font: inherit; color: var(--i); background: none; border: 0; padding: 0; text-decoration: underline; cursor: pointer; }

.quiz-controls { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-bottom: 18px; }
.quiz-controls label { font-weight: 700; }
select {
  font: inherit; color: var(--ink); background: var(--surface);
  border: 1px solid var(--line); border-radius: var(--r-sm); padding: 8px 10px;
}
.quiz:empty { display: none; }
.quiz { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r-md); padding: clamp(18px, 3vw, 28px); }
.qcount { color: var(--muted); font-size: .9rem; }
.q { font: 700 clamp(1.25rem, 1rem + 1vw, 1.6rem)/1.3 var(--display); }
.blank { color: var(--i); letter-spacing: .1em; }
.opts { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 14px; }
.opt {
  font: 700 1.05rem var(--body); color: var(--ink); background: var(--paper); cursor: pointer;
  border: 2px solid var(--line); border-radius: var(--r-sm); padding: 10px 18px;
}
.opt:hover:not(:disabled) { border-color: var(--i); }
.opt:disabled { cursor: default; }
.opt.right { border-color: var(--right); background: var(--g-soft); color: var(--right); }
.opt.wrong { border-color: var(--wrong); color: var(--wrong); text-decoration: line-through; }
.why { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; }
.why .btn { margin-left: auto; }
.stats { color: var(--muted); margin-top: 14px; }
a.btn { display: inline-block; text-decoration: none; }
.end-row { display: flex; flex-wrap: wrap; gap: 10px; margin: 0; }

/* Quick check at the end of each topic */
.check { margin-top: 28px; }
.check h3::before { content: "✎ "; color: var(--i); }
.check .quiz { border: 2px solid var(--i-soft); }

/* Verb drill */
.seg-group { display: inline-flex; border: 2px solid var(--i); border-radius: var(--r-sm); overflow: hidden; margin-bottom: 16px; }
.seg { font: 700 .95rem var(--body); cursor: pointer; border: 0; padding: 8px 16px; background: var(--surface); color: var(--i); }
.seg + .seg { border-left: 2px solid var(--i); }
.seg[aria-pressed="true"] { background: var(--i); color: var(--surface); }
.dverb { font: 800 clamp(2rem, 1.4rem + 3vw, 3.2rem)/1.1 var(--display); margin: 4px 0 10px; }
.dopts { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 10px; margin-bottom: 14px; }
.dopt { display: grid; grid-template-columns: auto minmax(0, 1fr); align-items: center; gap: 4px 12px; text-align: left; }
.dopt .formula, .dopt small { grid-column: 2; }
.dopt .formula { font-size: 1rem; }
.dopt small { color: var(--muted); font-weight: 400; font-size: .85rem; }
.dopt.right small, .dopt.wrong small { color: inherit; }
.dopt.wrong { text-decoration: none; }
.dopt kbd {
  font: 700 .75rem var(--body); color: var(--muted); border: 1px solid var(--line);
  border-radius: 4px; padding: 1px 6px;
}
.dopt:has(small) kbd { grid-row: 1 / span 2; }
@media (hover: none) {
  .dopt kbd { display: none; }
  .dopt { grid-template-columns: minmax(0, 1fr); }
  .dopt .formula, .dopt small { grid-column: 1; }
}
.dresult .ans { border-top: 1px solid var(--line); padding-top: 12px; margin-top: 12px; }
.dresult .ans .formula { font-size: 1.1rem; }
.dgroups { list-style: none; padding: 0; margin: 0 0 10px; display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 0 24px; }
.dgroups li { display: flex; justify-content: space-between; align-items: center; gap: 10px; padding: 8px 0; border-bottom: 1px solid var(--line); }
.dgroups .formula { font-size: .9rem; white-space: nowrap; }
.dgroups b { color: var(--ink); }
.dgroups li.done b { color: var(--g); }

.foot { border-top: 1px solid var(--line); color: var(--muted); text-align: center; padding: 24px 16px 40px; font-size: .9rem; }

/* ---------- Small screens ---------- */
@media (max-width: 860px) {
  .layout { grid-template-columns: minmax(0, 1fr); gap: 0; }
  .toc {
    position: sticky; top: 0; z-index: 5; padding: 8px 0;
    background: var(--paper); border-bottom: 1px solid var(--line); margin: 0 -16px; padding-left: 16px;
  }
  .toc ol { display: flex; gap: 4px; overflow-x: auto; margin: 0; padding-right: 16px; scrollbar-width: none; }
  .toc a { white-space: nowrap; }
  .toc .prog { margin-left: 2px; }
  .legend { display: flex; gap: 14px; overflow-x: auto; white-space: nowrap; font-size: .8rem; padding: 4px 16px 0 10px; scrollbar-width: none; }
  main { padding-top: 32px; }
  .topic { scroll-margin-top: 96px; }
  .pattern, .block { scroll-margin-top: 96px; }
  .mrow { grid-template-columns: minmax(0, 1fr); }
  .two { grid-template-columns: 1fr; }
  .dialogue li { grid-template-columns: minmax(0, 1fr) auto; }
  .dialogue .who { grid-column: 1 / -1; margin-bottom: -8px; }
  table.pairs.senses thead { display: none; }
  table.pairs.senses tr { display: grid; padding: 8px 0; border-bottom: 1px solid var(--line); }
  table.pairs.senses td { border: 0; padding: 2px 0; }
}
@media (max-width: 560px) {
  table.pairs:not(.senses) thead { display: none; }
  table.pairs:not(.senses) tr { display: grid; padding: 8px 0; border-bottom: 1px solid var(--line); }
  table.pairs:not(.senses) td { border: 0; padding: 2px 0; }
  .why .btn { margin-left: 0; }
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .hero { background: #0c1120; border-bottom: 1px solid var(--line); }
}
:root[data-theme="dark"] .hero { background: #0c1120; border-bottom: 1px solid var(--line); }