/* ===== Темы ===== */
:root, [data-theme="dark"] {
  --bg: #0f1419;
  --panel: #1a2028;
  --panel-2: #232b35;
  --panel-3: #2a333f;
  --border: #2d3744;
  --text: #e6edf3;
  --muted: #7d8590;
  --accent: #58a6ff;
  --accent-text: white;
  --success: #3fb950;
  --success-bg: rgba(63,185,80,.18);
  --danger: #f85149;
  --danger-bg: rgba(248,81,73,.18);
  --warn: #d29922;
  --warn-bg: rgba(210,153,34,.18);
  --shadow: 0 8px 24px rgba(0,0,0,.4);
}

[data-theme="light"] {
  --bg: #f6f8fa;
  --panel: #ffffff;
  --panel-2: #f0f3f6;
  --panel-3: #e6ebf0;
  --border: #d0d7de;
  --text: #1f2328;
  --muted: #59636e;
  --accent: #0969da;
  --accent-text: white;
  --success: #1a7f37;
  --success-bg: rgba(26,127,55,.12);
  --danger: #cf222e;
  --danger-bg: rgba(207,34,46,.12);
  --warn: #9a6700;
  --warn-bg: rgba(154,103,0,.12);
  --shadow: 0 4px 12px rgba(0,0,0,.08);
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  font-size: 16px;
  min-height: 100dvh;
  overscroll-behavior-y: none;
}

#app {
  max-width: 900px;
  margin: 0 auto;
  padding: 10px 12px;
  padding-bottom: calc(78px + env(safe-area-inset-bottom, 0px));
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-height: 100dvh;
}

.muted { color: var(--muted); }
.small { font-size: 12px; }

/* ===== Верхняя панель ===== */
.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  background: color-mix(in srgb, var(--panel) 92%, transparent);
  backdrop-filter: saturate(140%) blur(8px);
  -webkit-backdrop-filter: saturate(140%) blur(8px);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 6px 8px 0;
  display: flex;
  flex-direction: column;
}

.topbar-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.brand {
  font-weight: 700;
  font-size: 16px;
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.progress-pill {
  font-size: 12px;
  color: var(--muted);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}

.icon-btn {
  background: transparent;
  border: none;
  color: var(--text);
  width: 44px;
  height: 44px;
  border-radius: 10px;
  cursor: pointer;
  font-size: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.icon-btn:active { background: var(--panel-2); }

/* ===== Прогресс ===== */
.progress-bar {
  height: 3px;
  background: transparent;
  margin-top: 4px;
  border-radius: 0 0 12px 12px;
  overflow: hidden;
}
#progressFill {
  height: 100%;
  background: var(--success);
  width: 0;
  transition: width .3s;
}

/* ===== Sidebar ===== */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: 320px;
  max-width: 88vw;
  background: var(--panel);
  border-right: 1px solid var(--border);
  padding: 16px;
  overflow-y: auto;
  transform: translateX(-100%);
  transition: transform .25s;
  z-index: 100;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.sidebar.open { transform: translateX(0); box-shadow: var(--shadow); }

.sidebar-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.sidebar-section {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}
.sidebar-section:last-child { border-bottom: none; }

.section-title {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--muted);
  margin-bottom: 4px;
  padding: 0 4px;
}

.mode-btn {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text);
  padding: 10px 12px;
  border-radius: 10px;
  cursor: pointer;
  text-align: left;
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 15px;
}
.mode-btn:hover { background: var(--panel-2); }
.mode-btn.active { background: var(--panel-2); border-color: var(--accent); }
.mode-btn .mode-emoji { font-size: 22px; }

.pill {
  display: inline-block;
  background: var(--panel-3);
  color: var(--muted);
  padding: 1px 7px;
  border-radius: 10px;
  font-size: 11px;
  margin-left: 4px;
  vertical-align: middle;
}
.mode-btn[data-mode="mistakes"] .pill { background: var(--danger); color: white; }
.mode-btn[data-mode="hard"] .pill { background: var(--warn); color: white; }
.mode-btn[data-mode="bookmarks"] .pill { background: var(--warn); color: white; }

.setting {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 4px;
  cursor: pointer;
  font-size: 14px;
  user-select: none;
}
.setting input { width: 18px; height: 18px; cursor: pointer; accent-color: var(--accent); }

.ghost-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
  padding: 9px 12px;
  border-radius: 8px;
  cursor: pointer;
  text-align: left;
  font-size: 14px;
}
.ghost-btn:active { background: var(--panel-2); }
.ghost-btn.danger { color: var(--danger); border-color: var(--danger); }
.ghost-btn.danger:active { background: var(--danger-bg); }

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.5);
  opacity: 0;
  pointer-events: none;
  transition: opacity .2s;
  z-index: 99;
}
.overlay.show { opacity: 1; pointer-events: auto; }

/* ===== Поиск (внутри сайдбара) ===== */
.search-row {
  display: flex;
  gap: 8px;
}
.search-row input[type="search"] {
  flex: 1;
  min-width: 0;
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 10px 12px;
  border-radius: 10px;
  font-size: 15px;
  -webkit-appearance: none;
}
.search-row input[type="number"] {
  width: 64px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 10px;
  border-radius: 10px;
  text-align: center;
  font-size: 15px;
  -moz-appearance: textfield;
}
.search-row input[type="number"]::-webkit-outer-spin-button,
.search-row input[type="number"]::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }

/* ===== Карточка ===== */
.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 14px 14px 16px;
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 280px;
  position: relative;
}

.q-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  margin-bottom: 10px;
}
.q-head .meta { display: flex; gap: 6px; flex-wrap: wrap; align-items: center; }
.badge-id, .q-type-badge, .mastered-badge {
  display: inline-block;
  padding: 3px 8px;
  border-radius: 6px;
  font-size: 11px;
  background: var(--panel-2);
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .5px;
  font-weight: 600;
}
.q-type-badge.multi { background: var(--warn-bg); color: var(--warn); }
.mastered-badge { background: var(--success-bg); color: var(--success); }

.bookmark-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--muted);
  font-size: 28px;
  padding: 0;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.bookmark-btn.on { color: var(--warn); }

.q-text {
  font-size: 16px;
  line-height: 1.5;
  margin-bottom: 12px;
  white-space: pre-wrap;
}

.options { display: flex; flex-direction: column; gap: 6px; }

.option {
  background: var(--panel-2);
  border: 2px solid transparent;
  border-radius: 12px;
  padding: 10px 12px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 10px;
  user-select: none;
  transition: background .12s, border-color .12s;
  min-height: 48px;  /* удобная тач-цель */
}
.option:active { background: var(--panel-3); }

.option .num {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  width: 30px;
  height: 30px;
  min-width: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 600;
  flex-shrink: 0;
}
.option .txt { flex: 1; line-height: 1.4; font-size: 15px; }

.option.selected { border-color: var(--accent); background: rgba(88,166,255,.08); }
.option.correct {
  border-color: var(--success);
  background: var(--success-bg);
}
.option.wrong {
  border-color: var(--danger);
  background: var(--danger-bg);
}
.option.reveal-correct {
  border-color: var(--success);
  background: var(--success-bg);
}
.option.correct .num,
.option.reveal-correct .num { background: var(--success); border-color: var(--success); color: white; }
.option.wrong .num { background: var(--danger); border-color: var(--danger); color: white; }

.option.disabled { cursor: default; }

/* Подсказка после ответа */
.feedback {
  margin-top: 14px;
  padding: 10px 14px;
  border-radius: 10px;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
}
.feedback.ok { background: var(--success-bg); color: var(--success); }
.feedback.fail { background: var(--danger-bg); color: var(--danger); }

/* Доп. подсказка-кнопка (в test-режиме) */
.inline-actions {
  margin-top: 14px;
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}
.inline-actions button {
  background: var(--accent);
  color: var(--accent-text);
  border: none;
  padding: 11px 18px;
  border-radius: 10px;
  cursor: pointer;
  font-size: 15px;
  font-weight: 500;
}
.inline-actions button.secondary {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
}

.empty {
  color: var(--muted);
  text-align: center;
  padding: 60px 20px;
  font-size: 15px;
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
}
.empty .big-emoji { font-size: 48px; }
.loading { color: var(--muted); text-align: center; padding: 40px 0; }

/* ===== Экзамен — итоги ===== */
.exam-result[hidden] { display: none !important; }
.exam-result {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 32px 20px;
  text-align: center;
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 20px;
}
.exam-score-num { font-size: 48px; font-weight: 700; }
.exam-score-percent { font-size: 24px; color: var(--muted); }
.exam-verdict { font-size: 18px; margin-top: 12px; }
.exam-verdict.ok { color: var(--success); }
.exam-verdict.fail { color: var(--danger); }
.primary {
  background: var(--accent);
  color: var(--accent-text);
  border: none;
  padding: 12px 20px;
  border-radius: 10px;
  cursor: pointer;
  font-size: 15px;
  font-weight: 500;
}
.primary.big { padding: 14px 28px; font-size: 16px; }

/* ===== Нижняя навигация ===== */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: color-mix(in srgb, var(--panel) 92%, transparent);
  backdrop-filter: saturate(140%) blur(8px);
  -webkit-backdrop-filter: saturate(140%) blur(8px);
  border-top: 1px solid var(--border);
  padding: 8px 12px;
  padding-bottom: calc(8px + env(safe-area-inset-bottom, 0px));
  display: flex;
  gap: 10px;
  z-index: 50;
}
.nav-btn.primary {
  flex: 1;
  background: var(--accent);
  color: var(--accent-text);
  border: 1px solid var(--accent);
  padding: 14px;
  border-radius: 12px;
  cursor: pointer;
  font-size: 16px;
  font-weight: 600;
  min-height: 50px;
}
.nav-btn.primary:active { filter: brightness(.92); }
.nav-btn.primary.fail { background: var(--danger); border-color: var(--danger); }
.nav-btn.primary.ok { background: var(--success); border-color: var(--success); }
.nav-btn:disabled { opacity: .5; cursor: not-allowed; }

kbd {
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 5px;
  font-size: 11px;
  font-family: ui-monospace, monospace;
}

/* ===== Десктоп (≥720px) ===== */
@media (min-width: 720px) {
  #app { padding: 18px; padding-bottom: 18px; gap: 14px; }
  .topbar { position: static; }
  .bottom-nav {
    position: static;
    background: var(--panel);
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 12px;
    padding-bottom: 12px;
  }
  .brand { font-size: 18px; }
  .q-text { font-size: 17px; }
  .option .txt { font-size: 15.5px; }
}

/* анимация */
@keyframes slideIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}
.card.animate-in > * { animation: slideIn .2s ease-out; }