/* Vendored fonts — see task-26. woff2 in vendor/fonts/, weights 400/500 only. */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('vendor/fonts/inter-400-latin.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+2074, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('vendor/fonts/inter-400-cyrillic.woff2') format('woff2');
  unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116;
}
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url('vendor/fonts/inter-500-latin.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+2074, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url('vendor/fonts/inter-500-cyrillic.woff2') format('woff2');
  unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116;
}
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('vendor/fonts/inter-400-latin-ext.woff2') format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url('vendor/fonts/inter-500-latin-ext.woff2') format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
@font-face {
  font-family: 'Space Grotesk';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('vendor/fonts/space-grotesk-400-latin.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+2074, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: 'Space Grotesk';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('vendor/fonts/space-grotesk-400-latin-ext.woff2') format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
@font-face {
  font-family: 'Space Grotesk';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url('vendor/fonts/space-grotesk-500-latin.woff2') format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+2074, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: 'Space Grotesk';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url('vendor/fonts/space-grotesk-500-latin-ext.woff2') format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}

/* Mobile-first CSS reset + base styles */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  /* Surfaces */
  --bg: #0E0F1F;
  --surface: #181A2C;
  --surface-hi: #232542;
  /* Brand */
  --accent: #E94560;
  --accent-hi: #F25C77;
  --accent-lo: #C53550;
  --accent-tint: rgba(233, 69, 96, 0.12);
  /* Semantics */
  --success: #5DD49B;
  --success-tint: rgba(93, 212, 155, 0.12);
  --error: #FF6B6B;
  --error-tint: rgba(255, 107, 107, 0.12);
  --warning: #F2C94C;
  --warning-tint: rgba(242, 201, 76, 0.12);
  /* Text */
  --text: #E8E8F0;
  --text-dim: #B6B6C8;
  --text-faint: #A8A8BC;
  /* Borders */
  --border: rgba(255, 255, 255, 0.08);
  --border-hi: rgba(255, 255, 255, 0.15);
  /* Focus ring */
  --focus: var(--accent);
  /* On-color */
  --text-on-accent: #4A1B0C;
  --text-on-success: #04342C;
  /* Layout */
  --radius: 10px;
  --gap: 1rem;
  /* Gender colors */
  --gender-m: #4a9eff;
  --gender-f: #e94560;
  --gender-n: #f5a623;
  /* Topic accent colors */
  --topic-cases: #4a9eff;
  --topic-conjugation: #50c878;
  --topic-genders: #c084fc;
  --topic-vremena: #f59e0b;
  --topic-ostalo: #9ca3af;
  --topic-place-words: #14b8a6;
  /* Font stacks */
  --font-ui: 'Inter', system-ui, -apple-system, sans-serif;
  --font-display: 'Space Grotesk', system-ui, sans-serif;
  --font-mono: ui-monospace, 'SF Mono', Menlo, Consolas, monospace;
}

html { font-size: 16px; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-ui);
  line-height: 1.5;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

/* Header */
.site-header {
  background: var(--surface);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: max(0.75rem, env(safe-area-inset-top)) max(var(--gap), env(safe-area-inset-right)) 0.75rem max(var(--gap), env(safe-area-inset-left));
  border-bottom: 1px solid var(--accent);
}

.logo {
  text-decoration: none;
  min-height: 44px;
  display: inline-flex;
  align-items: baseline;
  gap: 0.35rem;
  padding: 0 0.75rem;
}
.logo-mark {
  font-family: var(--font-display);
  font-weight: 500;
  color: var(--accent);
  font-size: 22px;
  letter-spacing: -0.04em;
}
.logo-descriptor {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--text-dim);
}

.site-nav { display: flex; gap: 1rem; overflow-x: auto; scrollbar-width: none; }
.site-nav::-webkit-scrollbar { display: none; }
.site-nav a {
  color: var(--text);
  text-decoration: none;
  font-size: 0.9rem;
  opacity: 0.85;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  padding: 0 0.75rem;
}
.site-nav a:hover { opacity: 1; color: var(--accent); }
.site-nav a.active,
.site-nav a[aria-current] { opacity: 1; color: var(--accent); }
/* Desktop base: show text labels, hide icons */
.site-nav a i { display: none; }
.site-nav a .nav-label { display: inline; }

/* Visually hidden utility (accessible to screen readers) */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Responsive nav: icon-on-top layout at ≤560px */
@media (max-width: 560px) {
  .site-nav { gap: 0; justify-content: space-around; flex: 1; }
  .site-nav a {
    flex-direction: column;
    align-items: center;
    gap: 2px;
    padding: 0 0.4rem;
    font-size: 10px;
  }
  .site-nav a i { display: inline-flex; font-size: 22px; }
  .site-nav a .nav-label { font-size: 10px; }
}

/* Responsive nav: icon-only at ≤520px, labels visually hidden (screen-reader accessible) */
@media (max-width: 520px) {
  .site-nav a .nav-label {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
  }
}

/* Main */
.site-main { flex: 1; padding: var(--gap); padding-bottom: calc(var(--gap) + env(safe-area-inset-bottom)); padding-left: max(var(--gap), env(safe-area-inset-left)); padding-right: max(var(--gap), env(safe-area-inset-right)); max-width: 900px; margin: 0 auto; width: 100%; }

/* Hero */
.hero { text-align: center; padding: 2rem 0 1.5rem; }
.hero-wordmark { font-family: var(--font-display); font-weight: 500; color: var(--accent); letter-spacing: -0.04em; font-size: clamp(2.75rem, 7vw, 4rem); margin: 0; }
.hero-tagline { color: var(--text); font-size: 1.4rem; margin-top: 0.5rem; margin-bottom: 0; }
.hero-sub { color: var(--text-dim); margin-top: 0.25rem; }

/* Home nav cards */
.home-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--gap);
  margin-top: 1.5rem;
}

.card-link { flex: 1 1 240px; max-width: 360px; text-decoration: none; color: inherit; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: border-color 0.2s, transform 0.15s;
  cursor: pointer;
}

.card:hover { border-color: var(--accent); transform: translateY(-2px); }
.card-icon { font-size: 2rem; line-height: 1; display: block; margin-bottom: 0.5rem; color: var(--accent); }
.card h2 { font-size: 1.1rem; margin-bottom: 0.35rem; }
.card p { font-size: 0.85rem; color: var(--text-dim); }

/* Tables — no horizontal scroll on mobile */
table { width: 100%; border-collapse: collapse; font-size: clamp(0.75rem, 2vw, 0.95rem); }
th, td { padding: 0.4rem 0.5rem; border: 1px solid var(--border); text-align: left; }
th { background: var(--surface-hi); color: var(--text); }

/* Buttons */
.btn {
  display: inline-block;
  padding: 12px 16px;
  min-height: 44px;
  line-height: 1.2;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  font-size: 0.95rem;
  text-decoration: none;
  transition: opacity 0.15s;
}
.btn-primary { background: var(--accent-lo); color: #fff; padding: 11px 22px; border-radius: 8px; }
.btn-secondary { background: var(--surface-hi); color: var(--text); }
.btn:hover { opacity: 0.85; }

/* Utility */
.mt1 { margin-top: 1rem; }
.mt2 { margin-top: 2rem; }
.text-muted { color: var(--text-dim); }
.text-center { text-align: center; }

/* Rules page */
.page-title { font-size: 1.4rem; margin-bottom: 1rem; color: var(--accent); }

.rules-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--gap);
}

.topic-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  cursor: pointer;
  transition: border-color 0.2s, transform 0.15s, background-color 0.15s;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}
.topic-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}
.topic-card:active {
  background: var(--surface-hi);
  border-color: var(--border-hi);
  transform: translateY(0);
}
.topic-card:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

.topic-card-content {
  flex: 1;
}

.topic-card-chevron {
  color: var(--text-dim);
  font-size: 1.25rem;
  flex-shrink: 0;
  transition: color 0.2s;
}
.topic-card:hover .topic-card-chevron {
  color: var(--accent);
}

.topic-card-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
}
.topic-card-header h2 { font-size: 1rem; }
.topic-count {
  font-size: 0.75rem;
  color: var(--text-dim);
  white-space: nowrap;
}

.topic-examples {
  list-style: none;
  font-size: 0.8rem;
  color: var(--text-dim);
  font-style: italic;
}
.topic-examples li::before { content: "• "; }

/* Rules detail panel */
.rules-detail-panel { margin-top: 1.5rem; }

/* ── Bottom-sheet (reusable: rules, future /exercises) ─────────────── */
.bottom-sheet-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  z-index: 200;
  opacity: 0;
  transition: opacity 0.25s ease;
  pointer-events: none;
}
.bottom-sheet-backdrop.is-open {
  opacity: 1;
  pointer-events: auto;
}

.bottom-sheet {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 201;
  max-height: 90dvh;
  background: var(--surface);
  border-top-left-radius: calc(var(--radius) * 2);
  border-top-right-radius: calc(var(--radius) * 2);
  border-top: 1px solid var(--border-hi);
  overflow-y: auto;
  overscroll-behavior: contain;
  transform: translateY(100%);
  transition: transform 0.3s cubic-bezier(0.32, 0.72, 0, 1);
  outline: none;
}
.bottom-sheet.is-open {
  transform: translateY(0);
}
.bottom-sheet[hidden] {
  display: none;
}
.bottom-sheet__panel {
  margin-top: 0;
  padding: 0.25rem 0 1rem;
}
.bottom-sheet--tall { height: 90dvh; max-height: 90dvh; }
.bottom-sheet__close {
  position: absolute;
  top: 0.5rem;
  right: 0.75rem;
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 1.6rem;
  line-height: 1;
  cursor: pointer;
  padding: 0.25rem 0.5rem;
}
.bottom-sheet__close:hover { color: var(--text); }

/* Drag handle visual hint */
.bottom-sheet::before {
  content: '';
  display: block;
  width: 2.5rem;
  height: 0.25rem;
  background: var(--border-hi);
  border-radius: 999px;
  margin: 0.6rem auto 0;
}

.topic-detail { background: var(--surface); border-radius: var(--radius); padding: 1rem; }

.detail-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
  gap: 0.5rem;
}
.detail-header h2 { font-size: 1.1rem; color: var(--accent); }

.rule-block {
  margin-bottom: 1.25rem;
  padding: 0.5rem 0.75rem 1rem;
  border-left: 3px solid var(--border-hi);
  border-bottom: 1px solid var(--border);
}
.rule-block:last-child { border-bottom: none; margin-bottom: 0; }
.rule-block h3 { font-size: 0.95rem; margin-bottom: 0.5rem; color: var(--text); }
.rule-block--padezi { border-left-color: var(--topic-cases); }
.rule-block--glagoli { border-left-color: var(--topic-conjugation); }
.rule-block--rodovi { border-left-color: var(--topic-genders); }
.rule-block--vremena { border-left-color: var(--topic-vremena); }
.rule-block--ostalo { border-left-color: var(--topic-ostalo); }

.rule-text { font-size: 0.85rem; color: var(--text-dim); margin-bottom: 0.25rem; white-space: pre-line; }
.rule-list { padding-left: 1.2rem; font-size: 0.85rem; color: var(--text-dim); }
.rule-table { margin-top: 0.35rem; margin-bottom: 0.35rem; }

/* Vocabulary page */
.vocab-page { padding-bottom: 2rem; }

.vocab-filters { margin-bottom: 1.5rem; }

.filter-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: flex-end;
}

.filter-label {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  font-size: 0.85rem;
  color: var(--text-dim);
}

.filter-select {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.4rem 0.6rem;
  font-size: 0.9rem;
  cursor: pointer;
}
.filter-select:focus { outline: 2px solid var(--accent); outline-offset: 1px; }

/* Card area */
.card-area { min-height: 200px; }

/* Flashcard */
.flashcard {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  max-width: 500px;
  margin: 0 auto;
}

.progress-bar {
  height: 4px;
  background: var(--surface);
  border-radius: 2px;
  margin-bottom: 0.5rem;
  overflow: hidden;
}
.progress-bar-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 2px;
  transition: width 0.3s ease;
}

.progress-text {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-dim);
  margin-bottom: 1.5rem;
  text-align: center;
}

.flashcard-word {
  text-align: center;
  padding: 2rem 1rem;
  cursor: pointer;
  border-radius: var(--radius);
  border: 1px dashed var(--border);
  transition: border-color 0.2s, background 0.15s;
}
.flashcard-word:hover { border-color: var(--accent); background: rgba(233,69,96,0.05); }

.word-serb {
  display: block;
  font-size: clamp(1.6rem, 6vw, 2.2rem);
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.75rem;
  font-family: var(--font-display);
}

.flip-hint {
  display: block;
  font-size: 0.75rem;
  color: var(--text-dim);
}

/* Back of card */
.flashcard-back {
  text-align: center;
  padding: 1.5rem 1rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.35rem;
}

.word-sep { color: var(--text-dim); font-size: 1rem; }

.word-ru {
  font-size: clamp(1.1rem, 4vw, 1.5rem);
  color: var(--accent);
}

.word-case-req {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-top: 0.1rem;
}

.answer-btns {
  display: flex;
  gap: 1rem;
  justify-content: center;
  margin-top: 1.25rem;
}
.answer-btn { min-width: 110px; text-align: center; }

/* Done screen */
.vocab-done {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  text-align: center;
  max-width: 400px;
  margin: 0 auto;
}
.vocab-done h2 { font-size: 1.5rem; color: var(--accent); margin-bottom: 0.75rem; }
.done-stats { font-size: 1.1rem; margin-bottom: 1.5rem; color: var(--text-dim); }
.done-btns { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }

/* Empty state */
.vocab-empty { padding: 2rem 0; text-align: center; }

/* Exercises page */
.exercises-page { padding-bottom: 2rem; }
.exercises-train-page { padding-bottom: 2rem; }

.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: var(--gap);
  margin-bottom: 1.5rem;
}

.topic-label { font-size: 1rem; font-weight: 600; margin-bottom: 0.25rem; }

.question-area { min-height: 200px; }

.question-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  max-width: 560px;
  margin: 0 auto;
}

.question-prompt {
  font-family: var(--font-display);
  font-size: 24px;
  color: var(--text);
  margin: 1rem 0 1.5rem;
  text-align: center;
}

.options-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.6rem;
}
.options-grid form { display: contents; }

.btn-option {
  width: 100%;
  padding: 0.65rem 0.5rem;
  min-height: 44px;
  background: var(--surface-hi);
  color: var(--text);
  text-align: center;
}
.btn-option:hover { background: var(--accent); color: #fff; opacity: 1; }

.fill-blank-row { display: flex; gap: 0.5rem; align-items: center; }

.fill-input {
  flex: 1;
  background: transparent;
  color: var(--text);
  border: none;
  border-bottom: 2px solid var(--border-hi);
  border-radius: 0;
  padding: 0 6px;
  font-size: 16px;
  min-width: 80px;
  min-height: 44px;
  line-height: 1.2;
}
.fill-input:focus { outline: 2px solid var(--accent); outline-offset: 1px; }

.exercise-action-row {
  display: flex;
  gap: 0.5rem;
  margin-top: 1rem;
  flex-wrap: wrap;
}

.exercise-hint {
  margin-top: 0.75rem;
  padding: 0.6rem 0.9rem;
  background: var(--surface-hi);
  border-left: 3px solid var(--accent-lo);
  border-radius: var(--radius);
  font-size: 14px;
  color: var(--text-dim);
}

.result-card {
  background: var(--surface);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  max-width: 560px;
  margin: 0 auto;
  text-align: center;
}
.result-card--correct { background: var(--success-tint); border-color: var(--success); }
.result-card--wrong { background: var(--error-tint); border-color: var(--error); }

.result-icon { font-size: 2.5rem; margin: 0.5rem 0; }
.result-card--correct .result-icon { color: var(--success); }
.result-card--wrong .result-icon { color: var(--error); }

.result-verdict { font-size: 1.2rem; font-weight: 600; margin-bottom: 0.5rem; }
.result-card--correct .result-verdict { color: var(--success); }
.result-card--wrong .result-verdict { color: var(--error); }
.result-detail { font-size: 0.9rem; color: var(--text-dim); margin-bottom: 0.75rem; }
.result-answer--correct { color: var(--success); font-weight: 600; }
.result-input--correct { color: var(--success); border-bottom-color: var(--success); }
.result-input--wrong { color: var(--error); border-bottom-color: var(--error); }
.result-rule { font-size: 0.85rem; color: var(--text-dim); margin-bottom: 1.25rem; }
.result-rule a { color: var(--accent); }

.exercises-done {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  text-align: center;
  max-width: 500px;
  margin: 0 auto;
}
.exercises-done h2 { font-size: 1.5rem; color: var(--accent); margin-bottom: 0.75rem; }

.exercises-empty { padding: 2rem 0; text-align: center; }

.kbd-shortcut-footer {
  max-width: 560px;
  margin: 0.5rem auto 0;
  padding: 0.4rem 0.75rem;
  background: var(--surface-hi);
  border-radius: 0 0 var(--radius) var(--radius);
  display: flex;
  gap: 1rem;
  justify-content: center;
}
.kbd-row {
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: var(--text-faint);
  display: flex;
  align-items: center;
  gap: 0.35rem;
}
kbd {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-faint);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 5px;
  line-height: 1.5;
}

.mistakes-list {
  text-align: left;
  margin: 1rem 0;
  background: rgba(255,255,255,0.03);
  border-radius: var(--radius);
  padding: 1rem;
}
.mistakes-list h3 { font-size: 0.95rem; margin-bottom: 0.5rem; color: var(--text-dim); }
.mistakes-list ul { list-style: none; }
.mistakes-list li {
  padding: 0.35rem 0;
  font-size: 0.85rem;
  border-bottom: 1px solid var(--border);
}
.mistakes-list li:last-child { border-bottom: none; }
.mistake-prompt { color: var(--text); font-style: italic; }

/* Level filter on exercises index */
.level-filter {
  display: flex;
  flex-wrap: nowrap;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  gap: 0.5rem;
  align-items: center;
  margin-bottom: 1rem;
}
.level-filter-label { font-size: 0.85rem; color: var(--text-dim); margin-right: 0.25rem; flex-shrink: 0; }
.level-radio-label {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.3rem 0.75rem;
  border-radius: 20px;
  border: 1px solid var(--border);
  cursor: pointer;
  font-size: 0.85rem;
  transition: background 0.15s, border-color 0.15s;
  flex-shrink: 0;
  white-space: nowrap;
}
.level-radio-label input[type="radio"] {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  margin: 0;
  pointer-events: none;
}
.level-radio-label:has(input:checked) { border-color: var(--accent); background: var(--accent-lo); }
.level-radio-label:has(input:focus-visible) { outline: 2px solid var(--focus); outline-offset: 2px; }
.level-radio-label--easy:has(input:checked) { border-color: #4caf50; background: rgba(76,175,80,0.15); }
.level-radio-label--medium:has(input:checked) { border-color: #ff9800; background: rgba(255,152,0,0.15); }
.level-radio-label--hard:has(input:checked) { border-color: var(--accent); background: rgba(233,69,96,0.15); }

/* Level badge in question progress bar */
.level-badge {
  display: inline-block;
  margin-left: 0.5rem;
  padding: 0.1rem 0.45rem;
  border-radius: 10px;
  font-size: 0.7rem;
  font-weight: 600;
  vertical-align: middle;
  text-transform: uppercase;
}
.level-badge--easy { background: rgba(76,175,80,0.2); color: #4caf50; }
.level-badge--medium { background: rgba(255,152,0,0.2); color: #ff9800; }
.level-badge--hard { background: rgba(233,69,96,0.2); color: var(--accent); }

/* Topic tag in question card (§8.2) */
.topic-tag {
  display: inline-block;
  font-size: 11px;
  color: var(--accent-hi);
  background: var(--accent-tint);
  padding: 4px 10px;
  border-radius: 6px;
  margin-bottom: 0.5rem;
}

/* Idioms page */
.idioms-page { padding-bottom: 2rem; }
.idioms-train-page { padding-bottom: 2rem; }

.idioms-filters { margin-bottom: 1.25rem; }

.idioms-tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 1rem;
}

.idiom-tag-chip {
  display: inline-block;
  padding: 0.25rem 0.7rem;
  border-radius: 20px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-dim);
  font-size: 0.8rem;
  text-decoration: none;
  transition: border-color 0.15s, color 0.15s;
}
.idiom-tag-chip:hover { border-color: var(--accent); color: var(--accent); }
.idiom-tag-chip--inline {
  cursor: default;
  background: rgba(255,255,255,0.04);
}

.flashcard--idiom .word-serb {
  font-size: clamp(1.4rem, 4.5vw, 1.8rem);
  font-style: italic;
}

.idiom-example {
  margin-top: 0.75rem;
  padding: 0.5rem 0.75rem;
  background: rgba(255,255,255,0.04);
  border-left: 3px solid var(--border-hi);
  border-radius: 4px;
  text-align: left;
  width: 100%;
}
.idiom-example-serb { font-size: 0.9rem; color: var(--text); font-family: var(--font-display); }
.idiom-example-ru { font-size: 0.82rem; color: var(--text-dim); margin-top: 0.15rem; }

.idiom-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin-top: 0.75rem;
  justify-content: center;
}

/* Infographic system */
.ig-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.4rem;
  margin: 0.5rem 0;
}
@media (max-width: 540px) {
  .ig-grid { grid-template-columns: 1fr; }
}

.ig-cell {
  background: rgba(255,255,255,0.04);
  border-radius: 6px;
  padding: 0.4rem 0.6rem;
  font-size: 0.85rem;
  border-left: 3px solid var(--border-hi);
}
.ig-cell--m { border-left-color: var(--gender-m); }
.ig-cell--f { border-left-color: var(--gender-f); }
.ig-cell--n { border-left-color: var(--gender-n); }

.ig-label {
  display: block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-dim);
  margin-bottom: 0.1rem;
}

.ig-badge {
  display: inline-block;
  padding: 0.15rem 0.5rem;
  border-radius: 20px;
  font-size: 0.7rem;
  font-weight: 600;
  background: var(--surface-hi);
  color: var(--text);
  letter-spacing: 0.04em;
}

.ig-pronoun-row {
  background: rgba(255,255,255,0.06);
  border-radius: 4px;
}

.ig-case-block {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  margin-bottom: 0.75rem;
}

.ig-case-header {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
  flex-wrap: wrap;
}

.ig-case-badge {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text);
}

.ig-usage {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin: 0.25rem 0 0.5rem;
  font-style: italic;
}

.ig-cell-sub {
  font-size: 0.7rem;
  color: var(--text-dim);
  display: block;
  margin-top: 0.15rem;
}

.ig-examples {
  margin-top: 0.5rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.2rem 0.5rem;
}

.ig-example-row {
  display: contents;
}

.ig-serb {
  font-style: italic;
  font-size: 0.82rem;
  color: var(--text);
  font-family: var(--font-display);
}

.exercise-serb {
  font-family: var(--font-display);
}

.ig-ru {
  font-size: 0.82rem;
  color: var(--text-dim);
}

/* Conjugation infographic */
.ig-verb-badge {
  background: rgba(80, 200, 120, 0.15);
  border-color: var(--topic-conjugation);
  color: var(--topic-conjugation);
}

.ig-conj-table {
  width: 100%;
  border-collapse: collapse;
  margin: 0.5rem 0;
  font-size: 0.88rem;
}

.ig-conj-row td {
  padding: 0.25rem 0.4rem;
  border-bottom: 1px solid rgba(255,255,255,0.04);
}

.ig-conj-pronoun {
  color: var(--text-dim);
  width: 30%;
  font-size: 0.82rem;
}

.ig-conj-form {
  width: 70%;
  font-weight: 600;
  color: var(--text);
}

.ig-conj-form-header {
  text-align: left;
  padding: 0.25rem 0.4rem;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-dim);
  text-transform: lowercase;
  letter-spacing: 0.02em;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.ig-pronoun-row td {
  background: rgba(255,255,255,0.06);
  border-radius: 4px;
}

/* Poster grid layout */
.poster-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--gap);
}
@media (min-width: 640px) {
  .poster-grid { grid-template-columns: repeat(3, 1fr); }
}

.poster-tagline {
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 1.25rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.75rem;
}

/* Poster card upgrades */
.poster-card {
  display: block;
  text-decoration: none;
  color: inherit;
  background: var(--surface);
  border: 1px solid var(--border);
  border-top: 4px solid var(--accent);
  border-radius: var(--radius);
  padding: 1.25rem 1rem;
  cursor: pointer;
  transition: border-color 0.2s, transform 0.15s;
}
.poster-card:hover { transform: translateY(-2px); }
.poster-card-icon { font-size: 2.2rem; display: block; margin-bottom: 0.6rem; color: var(--accent); }
.poster-card-title { font-size: 1rem; font-weight: 600; margin-bottom: 0.25rem; }
.poster-card-sub { font-size: 0.8rem; color: var(--text-dim); margin-bottom: 0.5rem; }
.poster-card-count {
  display: inline-block;
  font-size: 0.7rem;
  background: var(--surface-hi);
  color: var(--text-dim);
  border-radius: 99px;
  padding: 0.1rem 0.5rem;
  margin-top: 0.25rem;
}

/* Gender infographic cards */
.genders-infographic {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.ig-gender-card {
  background: var(--surface);
  border-radius: 10px;
  border-left: 4px solid var(--accent);
  padding: 1rem 1.2rem;
}

.ig-gender-card--m { border-left-color: var(--gender-m); }
.ig-gender-card--f { border-left-color: var(--gender-f); }
.ig-gender-card--n { border-left-color: var(--gender-n); }

.ig-gender-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}

.ig-gender-label {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1;
  min-width: 2rem;
}

.ig-gender-card--m .ig-gender-label { color: var(--gender-m); }
.ig-gender-card--f .ig-gender-label { color: var(--gender-f); }
.ig-gender-card--n .ig-gender-label { color: var(--gender-n); }

.ig-gender-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
}

.ig-gender-endings {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  margin: 0.5rem 0;
}

.ig-gender-ending-row {
  display: flex;
  gap: 0.5rem;
  align-items: baseline;
}

.ig-gender-ending-pattern {
  font-size: 0.92rem;
  color: var(--text);
}

.ig-gender-exceptions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin: 0.5rem 0;
}

.ig-badge--exception {
  background: rgba(245, 166, 35, 0.12);
  color: var(--gender-n);
  border-color: rgba(245, 166, 35, 0.3);
  font-size: 0.72rem;
}

.ig-section-heading {
  margin: 1.5rem 0 0.5rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.ig-plural-card {
  border-left-color: var(--accent);
}

.ig-plural-card .ig-gender-title {
  font-size: 1rem;
}

.ig-usage--pre {
  white-space: pre-wrap;
  font-style: normal;
}

/* Paradigm tables (declensions in "Дополнительные правила") */
.ig-paradigm {
  margin: 0.6rem 0;
  overflow-x: auto;
}

.ig-paradigm-title {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 0.3rem;
}

.ig-paradigm-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}

.ig-paradigm-table th,
.ig-paradigm-table td {
  padding: 0.28rem 0.5rem;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  text-align: left;
}

.ig-paradigm-table thead th {
  font-size: 0.78rem;
  color: var(--text-dim);
  font-weight: 600;
}

.ig-paradigm-case {
  width: 2.4rem;
  color: var(--text-dim);
  font-size: 0.82rem;
}

/* Vremena infographic — sections grouped by tense */
.vremena-infographic {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.ig-tense-section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 4px solid var(--topic-vremena);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
}

.ig-tense-section--prezent { border-left-color: var(--topic-conjugation); }
.ig-tense-section--futur { border-left-color: var(--topic-cases); }
.ig-tense-section--other { border-left-color: var(--topic-ostalo); }

.ig-tense-header {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  margin-bottom: 0.6rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.ig-tense-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
}

.ig-tense-sub {
  font-size: 0.78rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.ig-tense-rule {
  padding: 0.6rem 0;
  border-bottom: 1px dashed rgba(255,255,255,0.05);
}
.ig-tense-rule:last-child { border-bottom: none; }

.ig-tense-rule-header {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.3rem;
}

.ig-tense-formula {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  margin: 0.25rem 0 0.4rem;
  padding: 0.3rem 0.5rem;
  background: rgba(245, 158, 11, 0.08);
  border-radius: 4px;
  font-size: 0.85rem;
}

.ig-tense-formula-text {
  color: var(--text);
  font-style: italic;
}

/* ── htmx loading indicator ──────────────────────────────────────── */
/* htmx hides .htmx-indicator (opacity:0) and shows it when the
   requesting element has .htmx-request (standard htmx mechanism). */
.htmx-indicator {
  display: inline-block;
  width: 1em;
  height: 1em;
  border: 2px solid var(--border-hi);
  border-top-color: var(--accent);
  border-radius: 50%;
  opacity: 0;
  transition: opacity 0.15s;
  vertical-align: middle;
  margin-left: 0.4em;
  animation: htmx-spin 0.7s linear infinite;
}
.htmx-request .htmx-indicator,
.htmx-indicator.htmx-request {
  opacity: 1;
}
@keyframes htmx-spin {
  to { transform: rotate(360deg); }
}

/* ── iOS install hint banner ─────────────────────────────────────── */
.ios-install-hint {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.65rem 1rem;
  background: var(--surface-hi);
  border-bottom: 1px solid var(--border-hi);
  color: var(--text-dim);
  font-size: 0.875rem;
}
.ios-install-hint[hidden] { display: none; }
.ios-install-hint__msg { flex: 1; }
.ios-install-hint__msg .ti { font-size: 1rem; vertical-align: middle; color: var(--accent); }
.ios-install-hint__close {
  background: none;
  border: none;
  color: var(--text-faint);
  font-size: 1.2rem;
  line-height: 1;
  cursor: pointer;
  padding: 0 0.25rem;
}

/* ── htmx error banner ───────────────────────────────────────────── */
.htmx-error-banner {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.65rem 1rem;
  background: var(--error-tint);
  border-bottom: 1px solid var(--error);
  color: var(--error);
  font-size: 0.9rem;
}
.htmx-error-banner[hidden] { display: none; }
.htmx-error-banner__msg { flex: 1; }
.htmx-error-banner__close {
  background: none;
  border: none;
  color: var(--error);
  font-size: 1.2rem;
  line-height: 1;
  cursor: pointer;
  padding: 0 0.25rem;
}

/* ── Alphabet page ── */
.alphabet-page { max-width: 860px; margin: 0 auto; }
.alphabet-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--gap);
  margin-top: 1.5rem;
}
.alphabet-cell {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  /* Non-interactive reference tile: kill mobile tap-flash and accidental
     text-selection on scroll. On Android Chrome / Samsung Internet both the
     tap-highlight and the text-selection color inherit theme-color (#E94560),
     so a scroll-drag tints letters coral — suppress both. Digraph red border
     below is unaffected (it's border-color, not highlight/selection). */
  -webkit-tap-highlight-color: transparent;
  -webkit-user-select: none;
  user-select: none;
}
.alphabet-cell--digraph {
  border-color: var(--accent);
  background: var(--surface-hi);
  box-shadow: 0 0 0 1px var(--accent-tint);
}
.alphabet-cell__scripts {
  display: flex;
  align-items: baseline;
  gap: 0.4rem;
}
.alphabet-cell__cyr {
  font-size: 2rem;
  font-weight: 500;
  color: var(--text);
  line-height: 1;
}
.alphabet-cell__sep {
  color: var(--text-faint);
  font-size: 1.2rem;
}
.alphabet-cell__lat {
  font-size: 1.5rem;
  font-weight: 500;
  color: var(--text-dim);
  line-height: 1;
}
.alphabet-cell--digraph .alphabet-cell__lat {
  color: var(--accent-hi);
}
.alphabet-cell__pron {
  font-size: 0.8rem;
  color: var(--text-dim);
  line-height: 1.4;
}

/* ── Site footer ── */
.site-footer {
  text-align: center;
  padding: 1.5rem 1rem;
  border-top: 1px solid var(--border);
  margin-top: 2rem;
}
.site-footer__link {
  font-size: 0.85rem;
  color: var(--text-dim);
  text-decoration: none;
}
.site-footer__link:hover { color: var(--accent); }

/* ── Contact page ── */
.contact-page { max-width: 520px; margin: 0 auto; padding: 0 1rem 2rem; }
.contact-intro { color: var(--text-dim); margin-bottom: 1.5rem; }
.contact-form { display: flex; flex-direction: column; gap: 1.25rem; }
.contact-field { display: flex; flex-direction: column; gap: 0.35rem; }
.contact-label { font-size: 0.9rem; font-weight: 500; color: var(--text-dim); }
.contact-input,
.contact-textarea {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-family: inherit;
  font-size: 1rem;
  padding: 0.6rem 0.8rem;
  resize: vertical;
  transition: border-color 0.2s;
}
.contact-input:focus,
.contact-textarea:focus { outline: 2px solid var(--focus); outline-offset: 1px; border-color: var(--accent); }
.contact-submit { align-self: flex-start; }
.contact-error {
  background: rgba(233,69,96,0.1);
  border: 1px solid var(--accent);
  border-radius: 8px;
  color: var(--error);
  font-size: 0.9rem;
  padding: 0.6rem 0.9rem;
}
.contact-sent {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  padding: 3rem 1rem 2rem;
  text-align: center;
}
.contact-sent__icon { font-size: 3rem; color: var(--success); }
.contact-sent__title { font-size: 1.4rem; font-weight: 600; margin: 0; }
.contact-sent__body { color: var(--text-dim); margin: 0 0 0.5rem; }