:root {
  --bg: #f4f7fb;
  --panel: #ffffff;
  --panel-2: #f8fafc;
  --text: #182230;
  --muted: #5f6b7a;
  --line: #d7dfeb;
  --accent: #2563eb;
  --accent-soft: rgba(37, 99, 235, 0.12);
  --success: #15803d;
  --success-soft: rgba(21, 128, 61, 0.12);
  --danger: #dc2626;
  --danger-soft: rgba(220, 38, 38, 0.12);
  --shadow: 0 10px 24px rgba(15, 23, 42, 0.08);
}

body.dark-theme {
  --bg: #0f172a;
  --panel: #111c34;
  --panel-2: #17233d;
  --text: #e5edf9;
  --muted: #9fb0c9;
  --line: #2b3b5f;
  --accent: #60a5fa;
  --accent-soft: rgba(96, 165, 250, 0.15);
  --success: #4ade80;
  --success-soft: rgba(74, 222, 128, 0.15);
  --danger: #f87171;
  --danger-soft: rgba(248, 113, 113, 0.15);
  --shadow: 0 14px 28px rgba(2, 6, 23, 0.35);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}
a { color: inherit; text-decoration: none; }
button, input, select { font: inherit; }
button { cursor: pointer; }

.skip-link {
  position: absolute;
  left: 16px;
  top: -48px;
  z-index: 1000;
  padding: 10px 14px;
  background: var(--accent);
  color: #fff;
  border: 1px solid var(--accent);
}
.skip-link:focus {
  top: 16px;
}

.site-shell { max-width: 1400px; margin: 0 auto; padding: 24px; }
.home-header, .trainer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.home-header { margin-bottom: 28px; }
.home-header h1, .trainer-header h1 { margin: 0; font-size: clamp(1.3rem, 2vw, 1.7rem); }
.brand-mark {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
}
.brand-logo {
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  border-radius: 14px;
  background: linear-gradient(135deg, var(--accent), #0f3ea8);
  color: #fff;
  font-weight: 800;
  letter-spacing: 0.06em;
  box-shadow: var(--shadow);
}
.brand-copy { display: grid; gap: 2px; }
.eyebrow { margin: 0 0 2px; color: var(--accent); font-weight: 700; font-size: 0.9rem; }
.brand-subtitle { margin: 0; color: var(--muted); font-size: 0.95rem; }
.home-subtitle { max-width: 720px; margin: 10px 0 0; color: var(--muted); }
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}
.exam-card, .sidebar-card, .question-card, .modal-card {
  background: var(--panel);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}
.exam-card {
  border-radius: 0;
  padding: 22px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 300px;
}
.card-badge {
  margin: 0 0 10px;
  color: var(--accent);
  font-weight: 700;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.exam-card h2 { margin: 0 0 10px; font-size: 1.35rem; }
.card-description { margin: 0 0 18px; color: var(--muted); }
.card-stats { margin: 0; display: grid; gap: 12px; }
.card-stats div { padding: 10px 12px; background: var(--panel-2); }
.card-stats dt { font-size: 0.82rem; color: var(--muted); }
.card-stats dd { margin: 4px 0 0; font-weight: 700; }

.primary-link, .primary-button, .ghost-button, .danger-button, .icon-button {
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--text);
  padding: 10px 14px;
  min-height: 42px;
  transition: 0.2s ease;
}
.primary-link, .primary-button {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.primary-link:hover, .primary-button:hover, .ghost-button:hover, .danger-button:hover, .icon-button:hover,
.primary-link:focus-visible, .primary-button:focus-visible, .ghost-button:focus-visible, .danger-button:focus-visible, .icon-button:focus-visible,
.back-link:hover, .back-link:focus-visible {
  transform: translateY(-1px);
  box-shadow: 0 8px 20px rgba(15, 23, 42, 0.08);
}
.primary-link:focus-visible, .primary-button:focus-visible, .ghost-button:focus-visible, .danger-button:focus-visible,
.icon-button:focus-visible, .back-link:focus-visible, .mode-button:focus-visible, .pagination button:focus-visible,
.answer-input:focus-visible, .search-form input:focus-visible, select:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.28);
  outline-offset: 2px;
}
.ghost-button { background: var(--panel); }
.danger-button { color: var(--danger); }
.icon-button { display: inline-flex; align-items: center; gap: 8px; }
.theme-switch, .icon-button { white-space: nowrap; }
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  background: var(--panel);
}

.trainer-shell { display: grid; gap: 18px; }
.trainer-header {
  background: var(--panel);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  padding: 10px 14px;
  flex-wrap: nowrap;
}
.header-left, .header-tools { display: flex; align-items: center; gap: 10px; }
.header-left { min-width: 0; }
.header-left h1 { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; font-size: 1.1rem; }
.compact-brand {
  margin-bottom: 0;
  margin-left: 2px;
}
.compact-brand .brand-logo {
  width: 38px;
  height: 38px;
  border-radius: 12px;
  font-size: 0.88rem;
}
.compact-brand .eyebrow {
  margin: 0;
  font-size: 0.82rem;
}
.header-tools { flex-wrap: nowrap; margin-left: auto; }
.search-form { display: flex; align-items: center; gap: 8px; }
.search-form input {
  width: 130px;
  min-height: 42px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  background: var(--panel-2);
  color: var(--text);
}
.layout-grid {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: 18px;
  align-items: start;
}
.sidebar-card { padding: 18px; }
.sticky-panel { position: sticky; top: 18px; }
.panel-section + .panel-section { margin-top: 18px; }
.panel-section h2 { margin: 0 0 10px; font-size: 1rem; }
.mode-switcher {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}
.mode-button {
  min-height: 42px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--text);
  transition: 0.2s ease;
}
.mode-button:hover,
.mode-button:focus-visible {
  transform: translateY(-1px);
  box-shadow: 0 8px 20px rgba(15, 23, 42, 0.08);
}
.mode-button.is-active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}
select, .panel-section input {

  margin-top: 8px;
  min-height: 42px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  background: var(--panel-2);
  color: var(--text);
}
.full-width { width: 100%; margin-top: 10px; }
.stats-block { font-size: 0.95rem; }
.stat-line, .progress-label-row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 6px 0;
  font-size: 0.92rem;
}
.stat-line span, .progress-label-row span { color: var(--muted); }
.progress-wrap { margin-top: 10px; }
.progress-bar {
  width: 100%; height: 10px; background: var(--panel-2); border: 1px solid var(--line); overflow: hidden;
}
.progress-bar span { display: block; height: 100%; width: 0; background: var(--accent); }

.content-area { min-width: 0; }
.notification, .search-state {
  padding: 12px 14px;
  border: 1px solid var(--line);
  background: var(--panel);
  box-shadow: var(--shadow);
  margin-bottom: 14px;
}
.notification.success { border-color: var(--success); background: var(--success-soft); }
.notification.error { border-color: var(--danger); background: var(--danger-soft); }
.print-variant-title { display: none; }
.print-source-link { display: none; }
.notification:not(.is-hidden), .search-state:not(.is-hidden) { border-left-width: 4px; }
.question-list { display: grid; gap: 14px; }
.question-card { padding: 18px; }
.question-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 12px;
}
.question-id {
  display: inline-flex;
  align-items: center;
  font-size: 0.84rem;
  font-weight: 700;
  color: var(--accent);
  padding: 4px 8px;
  background: var(--accent-soft);
}
.question-text { margin: 0; font-size: 1rem; }
.answer-row {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 14px;
}
.answer-input {
  flex: 1 1 280px;
  min-height: 44px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  background: var(--panel-2);
  color: var(--text);
}
.answer-status {
  min-width: 120px;
  font-weight: 700;
  font-size: 0.95rem;
}
.answer-status.correct { color: var(--success); }
.answer-status.wrong { color: var(--danger); }
.answer-help { margin-top: 10px; font-size: 0.9rem; color: var(--muted); }
.variant-footer {
  display: flex;
  justify-content: center;
  margin-top: 16px;
}
.pagination {
  display: flex;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 16px;
  font-size: 0.84rem;
}
.pagination button {
  min-width: 38px;
  min-height: 36px;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--text);
}
.pagination button.active { background: var(--accent); color: white; border-color: var(--accent); }

.modal {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.55);
  display: grid;
  place-items: center;
  padding: 24px;
}
.modal-card { width: min(520px, 100%); padding: 20px; }
.modal-header {
  display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-bottom: 12px;
}
.modal-header h2 { margin: 0; font-size: 1.1rem; }
.modal-content { display: grid; gap: 10px; }
.modal-metric {
  display: flex; justify-content: space-between; padding: 10px 12px; background: var(--panel-2); border: 1px solid var(--line);
}

.is-hidden { display: none !important; }

@media (max-width: 1200px) {
  .trainer-header { flex-wrap: wrap; }
  .header-tools { flex-wrap: wrap; justify-content: flex-end; }
}

@media (max-width: 992px) {
  .layout-grid { grid-template-columns: 1fr; }
  .sticky-panel { position: static; }
}

@media (max-width: 768px) {
  .site-shell { padding: 14px; }
  .home-header, .trainer-header, .header-left, .header-tools, .search-form { flex-wrap: wrap; }
  .header-tools { margin-left: 0; }
  .compact-brand { order: -1; }
  .search-form input { width: 100%; }
  .search-form { width: 100%; }
  .search-form > * { flex: 1 1 auto; }
  .answer-row { flex-direction: column; align-items: stretch; }
  .answer-status { min-width: 0; }
  .mode-switcher { grid-template-columns: 1fr; }
}

@media (max-width: 576px) {
  .trainer-header { padding: 12px; }
  .header-left h1 { white-space: normal; }
  .question-card { padding: 14px; }
  .pagination { gap: 6px; }
}

@media print {
  body { background: white; color: black; }
  .sidebar-card, .header-tools, .pagination, .variant-footer, .notification, .search-state, .modal { display: none !important; }
  .site-shell { max-width: none; padding: 0; }
  .trainer-header {
    display: block;
    border: none;
    box-shadow: none;
    padding: 0 0 12px;
  }
  .trainer-header h1 { display: none !important; }
  .layout-grid { display: block; }
  .back-link { display: none !important; }
  .content-area {
    position: relative;
    z-index: 1;
  }
  .print-variant-title {
    display: block !important;
    margin: 0 0 8px;
    font-size: 1.15rem;
    font-weight: 700;
  }
  .print-source-link {
    display: block !important;
    margin: 0 0 14px;
    font-size: 0.95rem;
    color: #333;
  }
  .question-card {
    position: relative;
    z-index: 1;
    box-shadow: none;
    border: 1px solid #999;
    margin-bottom: 12px;
    break-inside: avoid;
  }
  .answer-row {
    display: block;
    margin-top: 10px;
  }
  .answer-row button, .answer-status { display: none !important; }
  .answer-help { display: none !important; }
  .answer-input {
    border: 1px solid #666;
    min-height: 34px;
    width: 100%;
    padding: 6px 8px;
    background: white;
  }
}