:root {
  --bg: #f6f3ee;
  --card: #fffdf9;
  --border: #e4ddd2;
  --text: #24211d;
  --muted: #847c70;
  --accent: #2f5fd0;
  --ok: #1f8a4c;
  --ko: #c0392b;
  --nom: #2f6fde;
  --gen: #c2410c;
  --dat: #15803d;
  --acc: #be123c;
  --ins: #7c3aed;
  --pre: #0e7490;
  --ru: "PT Serif", "Iowan Old Style", Georgia, "Times New Roman", serif;
  --shadow: 0 1px 2px rgba(60, 40, 20, .06), 0 6px 20px rgba(60, 40, 20, .06);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15171c; --card: #1d2027; --border: #2e323c; --text: #e7e4de; --muted: #9a958c;
    --accent: #7aa2ff; --ok: #4ade80; --ko: #f87171;
    --nom: #6ea0ff; --gen: #fb923c; --dat: #4ade80; --acc: #fb7185; --ins: #b794ff; --pre: #38bdf8;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 6px 20px rgba(0, 0, 0, .25);
  }
}

* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 15px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}
.hidden { display: none !important; }
.muted { color: var(--muted); }
.small { font-size: 12.5px; }
.center { text-align: center; }
kbd {
  font: 11px ui-monospace, Menlo, monospace; border: 1px solid var(--border); border-bottom-width: 2px;
  border-radius: 4px; padding: 0 4px; color: var(--muted);
}

button, select {
  font: inherit; color: var(--text); background: var(--card); border: 1px solid var(--border);
  border-radius: 8px; padding: 6px 12px; cursor: pointer;
}
button:hover, select:hover { border-color: var(--accent); }
button.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
button.primary kbd { color: #fff; border-color: rgba(255, 255, 255, .5); }
button.icon { padding: 2px 7px; border: 0; background: transparent; font-size: 14px; }
.link-btn { border: 0; background: none; color: var(--muted); text-decoration: underline; padding: 0; }

.c-nom { --c: var(--nom); } .c-gen { --c: var(--gen); } .c-dat { --c: var(--dat); }
.c-acc { --c: var(--acc); } .c-ins { --c: var(--ins); } .c-pre { --c: var(--pre); }

/* ---------- Top ---------- */

.topbar {
  display: flex; align-items: center; gap: 18px; flex-wrap: wrap; padding: 10px 20px;
  background: var(--card); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 5;
}
.brand { font: 700 19px var(--ru); white-space: nowrap; }
.brand small { font: 400 13px -apple-system, sans-serif; color: var(--muted); margin-left: 6px; }
.logo {
  display: inline-block; background: var(--text); color: var(--card); border-radius: 6px;
  padding: 0 6px; margin-right: 4px; font-size: 15px;
}
.tabs { display: flex; gap: 4px; }
.tabs button { border: 0; background: none; padding: 7px 14px; border-radius: 999px; color: var(--muted); }
.tabs button.on { background: var(--text); color: var(--card); }
.toggles { margin-left: auto; display: flex; gap: 14px; color: var(--muted); font-size: 13.5px; }
.toggles label { display: flex; align-items: center; gap: 5px; cursor: pointer; }
.toggles input { accent-color: var(--accent); }

.legend { display: flex; gap: 6px; flex-wrap: wrap; padding: 12px 20px 0; max-width: 1280px; margin: 0 auto; }
.chip {
  display: flex; align-items: center; gap: 6px; border-radius: 999px; padding: 4px 12px; font-size: 13.5px;
  background: var(--card);
}
.chip i { width: 10px; height: 10px; border-radius: 50%; background: var(--c); }
.chip small { color: var(--muted); font-family: var(--ru); }
.chip.on { border-color: var(--c, var(--text)); box-shadow: inset 0 0 0 1px var(--c, var(--text)); font-weight: 600; }

main { max-width: 1280px; margin: 0 auto; padding: 14px 20px 60px; }
.tab { display: none; }
.tab.on { display: block; }
.toolbar { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; margin-bottom: 14px; font-size: 14px; }
.toolbar label { display: flex; align-items: center; gap: 6px; color: var(--muted); }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(380px, 1fr)); gap: 14px; }
.card { background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 16px 18px; box-shadow: var(--shadow); }
h3 { font-size: 11.5px; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); margin: 16px 0 6px; }

.case-head { border-left: 4px solid var(--c, var(--text)); padding-left: 12px; margin-bottom: 8px; }
.case-head h2 { margin: 0; font-size: 18px; color: var(--c, var(--text)); }
.case-head .ru-name { font: 400 14px var(--ru); color: var(--muted); margin-left: 6px; }
.case-head .q { font-family: var(--ru); font-size: 15px; }
.case-head p { margin: 2px 0 0; font-size: 13.5px; }
.more { margin-top: 6px; font-size: 13px; padding: 4px 10px; }

/* ---------- Sentences and words ---------- */

.sent { padding: 10px 0; border-top: 1px dashed var(--border); }
.sent:first-child { border-top: 0; }
.ru { font: 21px/1.7 var(--ru); margin: 0; }
.es { margin: 2px 0 0; color: var(--muted); font-size: 14px; font-style: italic; }
.no-trans .sent .es { display: none; }
.sent-tools { display: flex; align-items: center; gap: 6px; margin-top: 2px; }
.rule { font-size: 11.5px; color: var(--muted); background: var(--bg); border-radius: 4px; padding: 0 6px; }

.w { cursor: help; border-radius: 4px; padding: 0 1px; transition: background .1s; outline: none; }
.w[class*="c-"] { border-bottom: 2px solid color-mix(in srgb, var(--c) 55%, transparent); }
.w .end { color: var(--c, inherit); font-weight: 700; }
.w .zero { color: var(--c); font-size: .55em; vertical-align: super; opacity: .7; margin-left: 1px; }
.sent .w .zero, .quiz-card .w .zero, .dict-ru .w .zero { display: none; }
.w.k-prep, .w.k-verb, .w.k-num { color: color-mix(in srgb, var(--text) 75%, var(--muted)); }
.w.k-prep { font-style: italic; }
.w:hover, .w.cur { background: color-mix(in srgb, var(--c, var(--accent)) 16%, transparent); }
.w.rel { background: color-mix(in srgb, var(--c, var(--accent)) 9%, transparent); box-shadow: 0 0 0 1px color-mix(in srgb, var(--c, var(--accent)) 40%, transparent); }
.no-color .w { border-bottom-color: transparent; }
.no-color .w .end, .no-color .w .zero { color: inherit; font-weight: inherit; }
.no-color .w:hover { background: color-mix(in srgb, var(--accent) 12%, transparent); }

/* ---------- Tooltip ---------- */

.tip {
  position: absolute; z-index: 20; width: 340px; max-width: calc(100vw - 16px);
  background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 12px 14px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, .18); font-size: 13.5px; pointer-events: none;
}
.tip.pinned { pointer-events: auto; border-color: var(--accent); }
.tip-head { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; margin-bottom: 6px; }
.tip-word { font: 700 24px var(--ru); }
.tip-word .end { color: var(--c, var(--accent)); }
.tip-tr { color: var(--muted); font-style: italic; }
.tip dl { display: grid; grid-template-columns: auto 1fr; gap: 3px 12px; margin: 0; }
.tip dt { color: var(--muted); }
.tip dd { margin: 0; }
.tip dd b { font-family: var(--ru); font-size: 15px; }
.badge { display: inline-block; background: var(--c); color: #fff; border-radius: 5px; padding: 0 7px; font-size: 12.5px; font-weight: 600; }
.end-pill { font-family: var(--ru); font-weight: 700; color: var(--c, var(--text)); }
.tip-why { margin-top: 9px; padding: 7px 9px; background: var(--bg); border-radius: 8px; }
.tip-info { margin-top: 7px; color: var(--muted); }
.tip-notes { margin: 8px 0 0; padding-left: 18px; color: var(--muted); }
.tip-notes li { margin: 2px 0; }
.tip-hint { margin-top: 8px; font-size: 12px; color: var(--muted); }
.tip-actions { margin-top: 10px; }
.tip-actions button { font-size: 13px; padding: 4px 10px; }

/* ---------- Tables ---------- */

.table-layout { display: grid; grid-template-columns: minmax(0, 1.6fr) minmax(260px, 1fr); gap: 14px; align-items: start; }
@media (max-width: 860px) { .table-layout { grid-template-columns: 1fr; } }
table.decl { width: 100%; border-collapse: collapse; }
.decl th, .decl td { text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--border); vertical-align: middle; }
.decl thead th { font-size: 12px; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); }
.decl tbody th { border-left: 4px solid var(--c); white-space: nowrap; }
.decl .case-name { color: var(--c); display: block; }
.decl th small { color: var(--muted); font: 400 13px var(--ru); }
.decl td.q { font-family: var(--ru); color: var(--muted); white-space: nowrap; }
.decl .ru { font-size: 19px; }
.decl td.focus { background: color-mix(in srgb, var(--c) 12%, transparent); box-shadow: inset 0 0 0 2px var(--c); border-radius: 6px; }
#table-info p { margin: 0 0 10px; }
#table-info b { font-family: var(--ru); font-size: 17px; }
#table-info ul { padding-left: 18px; margin: 0; color: var(--muted); font-size: 14px; }
#table-info li { margin: 4px 0; }

/* ---------- Quiz ---------- */

.quiz-stats { display: flex; align-items: center; gap: 22px; flex-wrap: wrap; margin-bottom: 14px; padding: 12px 18px; }
.stat b { font-size: 20px; }
.bars { display: flex; gap: 8px; align-items: flex-end; height: 44px; }
.bar { position: relative; width: 30px; height: 30px; background: var(--bg); border-radius: 4px; }
.bar span { position: absolute; bottom: 0; left: 0; right: 0; background: var(--c); opacity: .8; border-radius: 4px; }
.bar i { position: absolute; top: 32px; left: 0; right: 0; font-size: 10px; text-align: center; font-style: normal; color: var(--muted); }
.bars { margin-bottom: 12px; }
.quiz-card { max-width: 820px; margin: 0 auto; padding: 22px 26px; }
.quiz-q { margin: 0 0 6px; font-size: 13px; text-transform: uppercase; letter-spacing: .06em; }
.quiz-card .ru { font-size: 26px; }
.blank .gap { color: var(--accent); letter-spacing: 2px; }
.blank .lemma { color: var(--muted); font-size: .7em; }
.options { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin: 18px 0 4px; }
.opt { font: 20px var(--ru); padding: 12px 14px; text-align: left; border-radius: 10px; }
.opt kbd { margin-right: 6px; vertical-align: middle; }
.opt.right { border-color: var(--ok); background: color-mix(in srgb, var(--ok) 14%, var(--card)); }
.opt.wrong { border-color: var(--ko); background: color-mix(in srgb, var(--ko) 12%, var(--card)); }
.opt:disabled { cursor: default; color: var(--text); }
.explain { margin-top: 16px; padding: 14px 16px; border-radius: 10px; background: var(--bg); }
.explain.ok { border-left: 4px solid var(--ok); }
.explain.ko { border-left: 4px solid var(--ko); }
.explain p { margin: 0 0 8px; }
.explain .verdict { font-size: 17px; font-weight: 600; }
.explain .verdict b { font-family: var(--ru); }
.explain ul { margin: 0 0 10px; padding-left: 18px; color: var(--muted); }

/* ---------- Guide ---------- */

.guide-card ul { margin: 0; padding-left: 18px; }
.guide-card li { margin: 3px 0; }
.preps { display: flex; gap: 6px; flex-wrap: wrap; }
.prep-chip { font-family: var(--ru); border: 1px solid var(--c); color: var(--c); border-radius: 6px; padding: 0 8px; }
table.mini { width: 100%; border-collapse: collapse; font-size: 13px; }
.mini th, .mini td { padding: 4px 6px; border-bottom: 1px solid var(--border); text-align: left; }
.mini thead th { color: var(--muted); font-weight: 500; }
.mini tbody th { color: var(--muted); font-weight: 500; width: 34px; }
.mini .ru { font-size: 16px; line-height: 1.5; }
.rules ul li { margin: 6px 0; }

/* ---------- Dictionary ---------- */

#d-q { font: inherit; width: min(520px, 100%); padding: 8px 12px; border: 1px solid var(--border); border-radius: 8px; background: var(--card); color: var(--text); }
#d-q:focus { outline: none; border-color: var(--accent); }
.dict-kinds { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 14px; }
#dict-list h3:first-child { margin-top: 0; }
.dict-row { display: grid; grid-template-columns: minmax(150px, 220px) minmax(0, 1fr) auto; gap: 4px 16px; align-items: start; padding: 10px 0; border-top: 1px solid var(--border); }
#dict-list h3 + .dict-row, .dict-row:first-child { border-top: 0; }
.dict-ru { display: flex; align-items: baseline; gap: 6px; }
.dict-ru .ru { font-size: 20px; line-height: 1.4; }
.dict-g { font-size: 11.5px; color: var(--muted); font-style: italic; }
.dict-body p { margin: 0 0 3px; }
.dict-es { font-size: 15px; }
.dict-forms { font: 16px/1.6 var(--ru); }
.dict-forms .badge { font: 600 10.5px -apple-system, sans-serif; padding: 0 5px; margin-left: 4px; vertical-align: 2px; }
.dict-forms .muted { font: 12px -apple-system, sans-serif; }
.dict-ex .ru { font-size: 16px; }
.dict-ex .es { display: block; margin: 0; }
.dict-act { display: flex; gap: 6px; align-items: center; }
.dict-act button:not(.icon) { font-size: 13px; padding: 4px 10px; }
@media (max-width: 600px) {
  .dict-row { grid-template-columns: 1fr auto; }
  .dict-body { grid-column: 1 / -1; grid-row: 2; }
}

@media (max-width: 600px) {
  .tabs { flex-wrap: wrap; }
  .grid { grid-template-columns: 1fr; }
  .options { grid-template-columns: 1fr; }
  .toggles { margin-left: 0; }
  .ru { font-size: 19px; }
}

/* ---------- Flashcards ---------- */

.tab-badge {
  display: inline-block; min-width: 18px; margin-left: 4px; padding: 0 5px; border-radius: 999px;
  background: var(--acc); color: #fff; font-size: 11px; font-weight: 700; line-height: 18px; text-align: center;
}
.decks { display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); gap: 10px; margin-bottom: 14px; }
.deck { display: flex; flex-direction: column; align-items: flex-start; gap: 2px; text-align: left; padding: 10px 14px; border-radius: 12px; }
.deck span { font-size: 12.5px; }
.deck.on { border-color: var(--accent); box-shadow: inset 0 0 0 1px var(--accent); }
.deck-count { color: var(--muted); }
.deck-count i { font-style: normal; font-weight: 700; color: var(--acc); }
.cards-layout { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 14px; align-items: start; }
@media (max-width: 860px) { .cards-layout { grid-template-columns: 1fr; } }
.flash-progress { margin: 0 0 8px; font-size: 13.5px; }

.flash { display: grid; perspective: 1400px; }
.flash .face {
  grid-area: 1 / 1; backface-visibility: hidden; -webkit-backface-visibility: hidden;
  transition: transform .45s cubic-bezier(.2, .7, .2, 1);
  background: var(--card); border: 1px solid var(--border); border-radius: 16px; box-shadow: var(--shadow);
  min-height: 300px; padding: 26px 30px; display: flex; flex-direction: column; justify-content: center; align-items: center;
  text-align: center;
}
.flash .front { cursor: pointer; }
.flash .back { transform: rotateY(180deg); }
.flash.flipped .front { transform: rotateY(-180deg); pointer-events: none; }
.flash.flipped .back { transform: rotateY(0); }
.flash:not(.flipped) .back { pointer-events: none; }
.face p { margin: 6px 0; }
.face-label { font-size: 12px; text-transform: uppercase; letter-spacing: .07em; color: var(--muted); }
.face-hint { margin-top: 18px !important; }
.face .big { font: 700 40px/1.3 var(--ru); margin: 6px 0; }
.face .ru.big { font-size: 38px; }
.face .ru.plain { font-size: 21px; }
.back-body { width: 100%; }
.back-body .sent { text-align: left; border-top: 1px dashed var(--border); margin-top: 12px; padding-top: 12px; }
.back-body .tip-notes { text-align: left; display: inline-block; }
.flash-controls { display: flex; gap: 10px; justify-content: center; align-items: center; flex-wrap: wrap; margin-top: 14px; }
.flash-controls button { padding: 10px 18px; font-size: 15px; }
.flash-controls small { display: block; font-size: 11.5px; opacity: .8; }
.flash-controls .no { border-color: var(--ko); color: var(--ko); }
.flash-controls .yes { border-color: var(--ok); color: var(--ok); }
.flash-done { text-align: center; padding: 40px 30px; }
.flash-done h2 { margin: 0 0 8px; }

#boxes h3 { margin-top: 0; }
.box-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin-bottom: 10px; }
.lbox { background: var(--bg); border-radius: 10px; padding: 8px; text-align: center; }
.lbox b { display: block; font-size: 22px; }
.lbox span { font-size: 12px; color: var(--muted); }
.lbox small { display: block; font-size: 10.5px; }
.lbox.b5 b { color: var(--ok); }