:root {
  --bg: #ECEEE9;
  --surface: #F8F9F5;
  --surface-2: #E3E7DF;
  --ink: #16201B;
  --muted: #56625B;
  --line: #CDD4CA;
  --accent: #1E5747;
  --accent-ink: #F4F7F2;
  --accent-soft: #D5E4DC;
  --gilt: #9A6E17;
  --gilt-soft: #F0E4C6;
  --good: #2B7A4B;
  --good-soft: #D7EBDD;
  --bad: #A93A2E;
  --bad-soft: #F2DAD5;
  --shadow: 0 1px 2px rgba(22, 32, 27, .06), 0 6px 20px rgba(22, 32, 27, .06);
  --serif: "Newsreader", "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --sans: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --radius: 10px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0F1412; --surface: #161C19; --surface-2: #1E2622; --ink: #E3E8E2; --muted: #98A49D; --line: #2B3530;
    --accent: #7DBFA7; --accent-ink: #0F1412; --accent-soft: #21332C; --gilt: #D5AD57; --gilt-soft: #3A3120;
    --good: #6CC08D; --good-soft: #1D3226; --bad: #E58A7D; --bad-soft: #3B221E;
    --shadow: 0 1px 2px rgba(0,0,0,.3), 0 6px 20px rgba(0,0,0,.25);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0F1412; --surface: #161C19; --surface-2: #1E2622; --ink: #E3E8E2; --muted: #98A49D; --line: #2B3530;
  --accent: #7DBFA7; --accent-ink: #0F1412; --accent-soft: #21332C; --gilt: #D5AD57; --gilt-soft: #3A3120;
  --good: #6CC08D; --good-soft: #1D3226; --bad: #E58A7D; --bad-soft: #3B221E;
  --shadow: 0 1px 2px rgba(0,0,0,.3), 0 6px 20px rgba(0,0,0,.25);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 15px/1.55 var(--sans);
  padding-top: env(safe-area-inset-top, 0px);
}
a { color: var(--accent); }
:focus-visible { outline: 2px solid var(--gilt); outline-offset: 2px; border-radius: 4px; }
button { font: inherit; color: inherit; }
h1, h2, h3 { font-family: var(--serif); font-weight: 500; text-wrap: balance; line-height: 1.15; margin: 0; }
h1 { font-size: clamp(1.9rem, 4vw, 2.6rem); letter-spacing: -.01em; }
h2 { font-size: 1.55rem; }
h3 { font-size: 1.2rem; }
.eyebrow { font: 500 .72rem/1 var(--sans); letter-spacing: .12em; text-transform: uppercase; color: var(--muted); }
.muted { color: var(--muted); }
.mono, .ref { font-family: var(--mono); font-size: .8rem; }
.ref { color: var(--gilt); white-space: nowrap; }

/* ---------- top bar ---------- */
.topbar {
  position: sticky; top: env(safe-area-inset-top, 0px); z-index: 20;
  display: flex; align-items: center; gap: 18px;
  padding: 10px max(16px, calc((100vw - 1180px) / 2));
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); flex-shrink: 0; }
.brand-mark {
  display: grid; place-items: center; width: 36px; height: 36px; border-radius: 50%;
  background: var(--accent); color: var(--accent-ink); font: 600 1.3rem/1 var(--serif);
}
.brand-text { font: 600 1rem/1 var(--serif); }
.brand-text small { font: 400 .72rem/1.3 var(--sans); color: var(--muted); letter-spacing: .02em; }
.mainnav { display: flex; gap: 2px; overflow-x: auto; scrollbar-width: none; flex: 1; }
.mainnav::-webkit-scrollbar { display: none; }
.mainnav a {
  padding: 7px 11px; border-radius: 999px; text-decoration: none; color: var(--muted);
  font-weight: 500; font-size: .9rem; white-space: nowrap;
}
.mainnav a:hover { color: var(--ink); background: var(--surface-2); }
.mainnav a.active { color: var(--accent-ink); background: var(--accent); }
.theme-toggle {
  flex-shrink: 0; width: 34px; height: 34px; border-radius: 50%; border: 1px solid var(--line);
  background: var(--surface); cursor: pointer; font-size: 1rem;
}
@media (max-width: 760px) {
  .topbar { flex-wrap: wrap; gap: 8px 12px; }
  .mainnav { order: 3; flex-basis: 100%; }
  .theme-toggle { margin-left: auto; }
}

/* ---------- layout ---------- */
.page { max-width: 1180px; margin: 0 auto; padding-inline: 16px; padding-block: 28px 60px; outline: none; }
.foot { max-width: 1180px; margin: 0 auto; padding-inline: 16px; padding-block: 0 40px; color: var(--muted); font-size: .8rem; }
.foot p { max-width: 80ch; border-top: 1px solid var(--line); padding-top: 16px; margin: 0; }
.stack { display: flex; flex-direction: column; gap: 16px; }
.row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
.grid { display: grid; gap: 14px; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.pagehead { display: flex; flex-direction: column; gap: 8px; margin-bottom: 22px; }
.pagehead p { margin: 0; max-width: 70ch; color: var(--muted); }

.panel { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; }
.panel.lift { box-shadow: var(--shadow); }

.btn {
  display: inline-flex; align-items: center; gap: 6px; padding: 9px 15px; border-radius: 8px;
  border: 1px solid var(--line); background: var(--surface); color: var(--ink);
  font-weight: 500; font-size: .9rem; cursor: pointer; text-decoration: none; line-height: 1.2;
}
.btn:hover { border-color: var(--accent); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn.primary:hover { filter: brightness(1.08); }
.btn.ghost { background: transparent; }
.btn.small { padding: 6px 10px; font-size: .82rem; }
.btn[disabled] { opacity: .5; cursor: default; }

.chip { display: inline-flex; align-items: center; gap: 4px; padding: 2px 9px; border-radius: 999px; font-size: .75rem; font-weight: 500; background: var(--surface-2); color: var(--muted); white-space: nowrap; }
.chip.w { background: var(--accent-soft); color: var(--accent); }
.chip.c { background: var(--gilt-soft); color: var(--gilt); }
.chip.good { background: var(--good-soft); color: var(--good); }
.chip.bad { background: var(--bad-soft); color: var(--bad); }

.bar { height: 6px; background: var(--surface-2); border-radius: 99px; overflow: hidden; }
.bar > i { display: block; height: 100%; background: var(--accent); border-radius: 99px; }

select, input[type="search"], input[type="text"], textarea {
  font: inherit; color: var(--ink); background: var(--surface); border: 1px solid var(--line);
  border-radius: 8px; padding: 9px 11px; max-width: 100%;
}
textarea { width: 100%; min-height: 140px; resize: vertical; line-height: 1.5; }
label.check { display: flex; gap: 10px; align-items: flex-start; cursor: pointer; }
label.check input { margin-top: 4px; accent-color: var(--accent); }

/* ---------- dashboard ---------- */
.hero { display: grid; grid-template-columns: 1.4fr 1fr; gap: 18px; margin-bottom: 26px; }
.hero .intro { display: flex; flex-direction: column; gap: 12px; justify-content: center; }
.hero .intro p { margin: 0; color: var(--muted); max-width: 58ch; }
.stats { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; }
.stat { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px; }
.stat b { display: block; font: 500 1.9rem/1.1 var(--serif); font-variant-numeric: tabular-nums; }
.stat span { font-size: .8rem; color: var(--muted); }
@media (max-width: 760px) { .hero { grid-template-columns: 1fr; } }

.modlist { display: grid; gap: 10px; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); }
.mod {
  display: grid; grid-template-columns: 44px 1fr; gap: 12px; align-items: start;
  padding: 14px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  text-decoration: none; color: var(--ink);
}
.mod:hover { border-color: var(--accent); }
.mod .num { font: 500 1.4rem/1 var(--serif); color: var(--accent); text-align: center; padding-top: 3px; }
.mod.c .num { color: var(--gilt); }
.mod h3 { font-size: 1.05rem; margin-bottom: 8px; }
.mod .meta { display: flex; gap: 8px; align-items: center; font-size: .78rem; color: var(--muted); }
.mod .bar { flex: 1; }
.section-title { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; margin: 30px 0 12px; }
.section-title h2 { font-size: 1.35rem; }

/* ---------- reading ---------- */
.reader { display: grid; grid-template-columns: 250px 1fr; gap: 26px; align-items: start; }
.toc { position: sticky; top: 80px; display: flex; flex-direction: column; gap: 2px; max-height: calc(100vh - 100px); overflow: auto; }
.toc a { display: block; padding: 6px 10px; border-radius: 6px; color: var(--muted); text-decoration: none; font-size: .84rem; line-height: 1.35; border-left: 2px solid transparent; }
.toc a:hover { color: var(--ink); background: var(--surface-2); }
.toc a.done { color: var(--good); }
.toc .eyebrow { padding: 10px 10px 4px; }
@media (max-width: 900px) { .reader { grid-template-columns: 1fr; } .toc { position: static; max-height: none; } }

.note { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: clamp(18px, 3vw, 32px); scroll-margin-top: 90px; }
.note header { display: flex; flex-direction: column; gap: 6px; margin-bottom: 14px; padding-bottom: 14px; border-bottom: 1px solid var(--line); }
.note .who { font-family: var(--serif); font-style: italic; color: var(--muted); }
.prose { font-family: var(--serif); font-size: 1.1rem; line-height: 1.62; max-width: 72ch; }
.prose p { margin: 0 0 .8em; }
.prose ul, .prose ol { margin: 0 0 .9em; padding-left: 1.3em; }
.prose li { margin: .25em 0; }
.prose li::marker { color: var(--accent); }
.prose strong { font-weight: 600; color: var(--ink); }
.prose em { font-style: italic; }
.prose h4 { font: 600 .78rem/1.2 var(--sans); letter-spacing: .1em; text-transform: uppercase; color: var(--accent); margin: 1.3em 0 .5em; }
.tablewrap { overflow-x: auto; margin: 0 0 1em; }
.prose table { border-collapse: collapse; font-size: .95rem; min-width: 320px; }
.prose th, .prose td { border: 1px solid var(--line); padding: 6px 12px; text-align: left; }
.prose th { background: var(--surface-2); font-family: var(--sans); font-size: .8rem; font-weight: 600; }
.terms { display: grid; gap: 8px; margin-top: 16px; }
.term { display: grid; grid-template-columns: minmax(120px, 220px) 1fr; gap: 12px; padding: 10px 0; border-top: 1px dashed var(--line); font-size: .92rem; }
.term b { font-family: var(--serif); font-size: 1rem; font-weight: 600; }
@media (max-width: 600px) { .term { grid-template-columns: 1fr; gap: 2px; } }
.note footer { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 18px; padding-top: 14px; border-top: 1px solid var(--line); }

/* ---------- flashcards ---------- */
.flash-wrap { max-width: 720px; margin: 0 auto; display: flex; flex-direction: column; gap: 16px; }
.flash {
  min-height: 280px; background: var(--surface); border: 1px solid var(--line); border-radius: 14px;
  box-shadow: var(--shadow); padding: clamp(20px, 4vw, 40px); display: flex; flex-direction: column; gap: 16px; cursor: pointer;
}
.flash .q { font: 500 1.4rem/1.35 var(--serif); }
.flash .a { font: 1.12rem/1.55 var(--serif); border-top: 1px solid var(--line); padding-top: 16px; }
.flash .hint { margin-top: auto; font-size: .8rem; color: var(--muted); }
.grade { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.grade .btn { justify-content: center; padding: 12px; }
.grade .btn.bad { border-color: var(--bad); color: var(--bad); }
.grade .btn.good { border-color: var(--good); color: var(--good); }
.boxes { display: grid; grid-template-columns: repeat(5, 1fr); gap: 6px; }
.boxes div { background: var(--surface); border: 1px solid var(--line); border-radius: 8px; padding: 8px; text-align: center; font-size: .75rem; color: var(--muted); }
.boxes b { display: block; font: 500 1.3rem/1.1 var(--serif); color: var(--ink); font-variant-numeric: tabular-nums; }

/* ---------- quiz ---------- */
.quiz { max-width: 760px; margin: 0 auto; display: flex; flex-direction: column; gap: 14px; }
.options { display: grid; gap: 8px; }
.option {
  text-align: left; padding: 12px 14px; border-radius: 9px; border: 1px solid var(--line); background: var(--surface);
  cursor: pointer; font-family: var(--serif); font-size: 1.05rem; line-height: 1.4;
}
.option:hover:not([disabled]) { border-color: var(--accent); }
.option.ok { border-color: var(--good); background: var(--good-soft); }
.option.no { border-color: var(--bad); background: var(--bad-soft); }
.option[disabled] { cursor: default; }
.explain { font-size: .9rem; padding: 12px 14px; border-radius: 9px; background: var(--surface-2); }

/* ---------- exam ---------- */
.exam-q { display: flex; flex-direction: column; gap: 12px; }
.exam-q .qn { font: 500 1.3rem/1.35 var(--serif); }
.points { display: grid; gap: 6px; }
.points label { padding: 8px 10px; border-radius: 8px; background: var(--surface-2); font-size: .93rem; }
.gradebox { display: flex; align-items: center; gap: 20px; flex-wrap: wrap; }
.gradebox .big { font: 500 3.4rem/1 var(--serif); color: var(--accent); font-variant-numeric: tabular-nums; }
.timer { font: 500 1.1rem/1 var(--mono); font-variant-numeric: tabular-nums; }
.scale { display: grid; grid-template-columns: repeat(6, 1fr); gap: 4px; font-size: .72rem; text-align: center; }
.scale div { padding: 6px 2px; border-radius: 6px; background: var(--surface-2); color: var(--muted); }
.scale div.on { background: var(--accent); color: var(--accent-ink); }
@media (max-width: 520px) { .scale { grid-template-columns: repeat(3, 1fr); } }

/* ---------- lexicon ---------- */
.lex-tools { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.lex-tools input { flex: 1; min-width: 200px; }
.lex { display: grid; gap: 10px; grid-template-columns: repeat(auto-fill, minmax(330px, 1fr)); }
.thinker { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; display: flex; flex-direction: column; gap: 8px; }
.thinker h3 { font-size: 1.15rem; }
.thinker .dates { font-family: var(--mono); font-size: .78rem; color: var(--muted); }
.thinker p { margin: 0; font-family: var(--serif); font-size: 1rem; line-height: 1.5; }
.thinker ul { margin: 0; padding-left: 1.1em; font-family: var(--serif); font-size: .98rem; }
.thinker .works { font-size: .85rem; color: var(--muted); }
.thinker .works i { color: var(--ink); }
@media (max-width: 400px) { .lex, .modlist, .grid { grid-template-columns: 1fr; } }

/* ---------- search ---------- */
.results { display: flex; flex-direction: column; gap: 8px; }
.result { display: block; padding: 12px 14px; background: var(--surface); border: 1px solid var(--line); border-radius: 9px; text-decoration: none; color: var(--ink); }
.result:hover { border-color: var(--accent); }
.result small { color: var(--muted); display: block; margin-top: 4px; font-size: .84rem; }
mark { background: var(--gilt-soft); color: inherit; padding: 0 2px; border-radius: 3px; }

.empty { padding: 30px; text-align: center; color: var(--muted); }
.toast { position: fixed; left: 50%; bottom: calc(20px + env(safe-area-inset-bottom, 0px)); transform: translateX(-50%); background: var(--ink); color: var(--bg); padding: 9px 16px; border-radius: 99px; font-size: .88rem; z-index: 50; }

@media (prefers-reduced-motion: no-preference) {
  .flash, .option, .btn, .mod { transition: border-color .15s, background-color .15s, filter .15s; }
}