/* ============================================================
   Lingua Spark — стили
   Две темы через [data-theme], адаптив, анимации
   ============================================================ */

/* ---------- Темы ---------- */
:root {
  --radius: 14px;
  --radius-sm: 8px;
  --transition: 200ms cubic-bezier(.4, 0, .2, 1);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "SF Pro Display", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: "SF Mono", "JetBrains Mono", "Fira Code", Menlo, Consolas, monospace;
}

[data-theme="light"] {
  --bg: #faf7f2;
  --bg-elev: #ffffff;
  --bg-soft: #f1ece3;
  --text: #1a1a1a;
  --text-soft: #5b5b5b;
  --text-faint: #8a8a8a;
  --border: #e4ddcf;
  --accent: #2563eb;
  --accent-soft: #dbe7ff;
  --accent-text: #ffffff;
  --good: #16a34a;
  --good-soft: #d6f3df;
  --warn: #d97706;
  --warn-soft: #fce8c8;
  --bad: #dc2626;
  --bad-soft: #fbdedb;
  --shadow: 0 1px 3px rgba(0, 0, 0, .06), 0 8px 24px rgba(0, 0, 0, .05);
  --shadow-lg: 0 4px 12px rgba(0, 0, 0, .08), 0 24px 48px rgba(0, 0, 0, .08);
  --flame: #f97316;
}

[data-theme="dark"] {
  --bg: #0f172a;
  --bg-elev: #1e293b;
  --bg-soft: #1a2438;
  --text: #f8fafc;
  --text-soft: #cbd5e1;
  --text-faint: #94a3b8;
  --border: #334155;
  --accent: #60a5fa;
  --accent-soft: #1e3a5f;
  --accent-text: #0f172a;
  --good: #4ade80;
  --good-soft: #14352a;
  --warn: #fbbf24;
  --warn-soft: #3a2f12;
  --bad: #f87171;
  --bad-soft: #3a1f1f;
  --shadow: 0 1px 3px rgba(0, 0, 0, .3), 0 8px 24px rgba(0, 0, 0, .25);
  --shadow-lg: 0 4px 12px rgba(0, 0, 0, .4), 0 24px 48px rgba(0, 0, 0, .35);
  --flame: #fb923c;
}

/* ---------- Reset ---------- */
* { margin: 0; padding: 0; box-sizing: border-box; }
html, body { height: 100%; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  transition: background var(--transition), color var(--transition);
}
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }
button:disabled { cursor: default; opacity: .4; }

/* ---------- Layout ---------- */
#app {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  max-width: 980px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ---------- Header ---------- */
header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 0 14px;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--bg);
  z-index: 10;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; }
.brand .logo { font-size: 22px; }
.brand .name { letter-spacing: -.02em; }
.brand .name span { color: var(--accent); }

.header-actions { display: flex; align-items: center; gap: 8px; }

/* streak / goal chips */
.stat-chip {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 6px 10px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-soft);
}
.stat-chip .flame { color: var(--flame); }
.stat-chip.done { color: var(--good); border-color: var(--good-soft); background: var(--good-soft); }

.icon-btn {
  width: 38px; height: 38px;
  display: inline-flex; align-items: center; justify-content: center;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--bg-elev);
  font-size: 16px;
  transition: var(--transition);
}
.icon-btn:hover { border-color: var(--accent); color: var(--accent); }

/* ---------- Nav ---------- */
nav.tabs {
  display: flex;
  gap: 4px;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 24px;
}
.tab {
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  color: var(--text-soft);
  transition: var(--transition);
}
.tab:hover { color: var(--text); background: var(--bg-soft); }
.tab.active { color: var(--accent); background: var(--accent-soft); }

/* ---------- Screens ---------- */
.screen { display: none; flex: 1; padding-bottom: 40px; }
.screen.active { display: block; }

/* ---------- Study screen ---------- */
.study-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  padding-top: 12px;
}
.study-meta {
  display: flex;
  gap: 16px;
  font-size: 13px;
  color: var(--text-faint);
  font-weight: 500;
}
.study-meta b { color: var(--text-soft); }

.progress-bar {
  width: 100%;
  max-width: 520px;
  height: 6px;
  background: var(--bg-soft);
  border-radius: 999px;
  overflow: hidden;
}
.progress-bar > div {
  height: 100%;
  background: var(--accent);
  border-radius: 999px;
  transition: width 400ms ease;
}

/* Card */
.card-stage { perspective: 1600px; width: 100%; max-width: 560px; }
.card {
  position: relative;
  width: 100%;
  min-height: 340px;
  transform-style: preserve-3d;
  transition: transform 500ms cubic-bezier(.4, 0, .2, 1);
  cursor: pointer;
}
.card.flipped { transform: rotateY(180deg); }
.card-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 14px;
}
.card-back { transform: rotateY(180deg); }

.card-type {
  position: absolute;
  top: 16px; left: 16px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--text-faint);
}
.card-type.word { color: var(--accent); }
.card-type.phrase { color: var(--warn); }
.card-type.table-row { color: var(--good); }

.card .speak-btn {
  position: absolute;
  top: 14px; right: 14px;
  width: 34px; height: 34px;
  border-radius: 50%;
  background: var(--bg-soft);
  font-size: 15px;
  display: flex; align-items: center; justify-content: center;
  transition: var(--transition);
}
.card .speak-btn:hover { background: var(--accent-soft); }

.card-main {
  font-size: clamp(28px, 5vw, 42px);
  font-weight: 700;
  letter-spacing: -.02em;
}
.card-phon { font-family: var(--mono); font-size: 18px; color: var(--text-faint); }
.card-hint { font-size: 13px; color: var(--text-faint); margin-top: auto; }

.card-back .card-main { font-size: clamp(22px, 4vw, 30px); }
.card-translation { font-size: clamp(18px, 3vw, 22px); color: var(--text-soft); }
.card-example {
  font-size: 16px;
  color: var(--text);
  background: var(--bg-soft);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  width: 100%;
  cursor: text;
}
.card-example .word-span { transition: var(--transition); padding: 1px 1px; border-radius: 3px; }
.card-example .word-span:hover { background: var(--accent-soft); color: var(--accent); }
.card-example-ru { font-size: 14px; color: var(--text-faint); }

/* Answer buttons */
.answer-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  width: 100%;
  max-width: 560px;
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 200ms, transform 200ms;
  pointer-events: none;
}
.answer-row.shown { opacity: 1; transform: translateY(0); pointer-events: auto; }
.ans-btn {
  padding: 14px 8px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-elev);
  display: flex;
  flex-direction: column;
  gap: 2px;
  font-weight: 600;
  transition: var(--transition);
}
.ans-btn .label { font-size: 14px; }
.ans-btn .interval { font-size: 11px; color: var(--text-faint); font-weight: 500; }
.ans-btn .key { font-size: 10px; color: var(--text-faint); }
.ans-btn.again:hover { border-color: var(--bad); color: var(--bad); background: var(--bad-soft); }
.ans-btn.hard:hover { border-color: var(--warn); color: var(--warn); background: var(--warn-soft); }
.ans-btn.good:hover { border-color: var(--accent); color: var(--accent); background: var(--accent-soft); }
.ans-btn.easy:hover { border-color: var(--good); color: var(--good); background: var(--good-soft); }

.show-btn {
  width: 100%;
  max-width: 560px;
  padding: 14px;
  border-radius: var(--radius-sm);
  background: var(--accent);
  color: var(--accent-text);
  font-weight: 700;
  font-size: 15px;
  transition: var(--transition);
}
.show-btn:hover { filter: brightness(1.08); }

/* Empty / done states */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-faint);
}
.empty-state .big { font-size: 48px; margin-bottom: 12px; }
.empty-state h2 { color: var(--text); font-size: 22px; margin-bottom: 8px; }
.done-badge {
  display: inline-block;
  padding: 4px 12px;
  background: var(--good-soft);
  color: var(--good);
  border-radius: 999px;
  font-size: 12px;
  font-weight: 700;
  margin-bottom: 16px;
}

/* ---------- Materials screen ---------- */
.materials-section { margin-bottom: 36px; }
.section-title {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--text-faint);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}
.materials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 12px;
}
.mat-card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 16px;
  transition: var(--transition);
}
.mat-card:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: var(--shadow); }

/* Table */
.ls-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-bottom: 16px;
}
.ls-table caption {
  caption-side: top;
  text-align: left;
  padding: 12px 0 10px;
  font-weight: 700;
  font-size: 16px;
}
.ls-table th, .ls-table td {
  padding: 11px 14px;
  text-align: left;
  font-size: 14px;
  border-bottom: 1px solid var(--border);
}
.ls-table th {
  background: var(--bg-soft);
  font-weight: 700;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: .04em;
  color: var(--text-soft);
}
.ls-table tbody tr { cursor: pointer; transition: background var(--transition); }
.ls-table tbody tr:hover { background: var(--accent-soft); }
.ls-table tbody tr:last-child td { border-bottom: none; }
.ls-table .row-note { font-size: 11px; color: var(--text-faint); }
.add-srs-btn {
  margin-top: 8px;
  padding: 5px 10px;
  font-size: 11px;
  font-weight: 700;
  border-radius: 6px;
  border: 1px solid var(--accent);
  color: var(--accent);
  background: transparent;
  transition: var(--transition);
}
.add-srs-btn:hover { background: var(--accent); color: var(--accent-text); }
.add-srs-btn.added { background: var(--good-soft); border-color: var(--good); color: var(--good); }

/* Word list */
.word-list { display: flex; flex-direction: column; gap: 6px; }
.word-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
}
.word-row .w-left { display: flex; flex-direction: column; }
.word-row .w-en { font-weight: 600; }
.word-row .w-ipa { font-family: var(--mono); font-size: 12px; color: var(--text-faint); }
.word-row .w-ru { font-size: 14px; color: var(--text-soft); }
.word-row .w-actions { display: flex; gap: 6px; align-items: center; }
.mini-speak { font-size: 14px; opacity: .6; transition: var(--transition); }
.mini-speak:hover { opacity: 1; color: var(--accent); }

/* ---------- Stats screen ---------- */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 12px;
  margin-bottom: 28px;
}
.stat-box {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  text-align: center;
}
.stat-box .num { font-size: 32px; font-weight: 700; color: var(--accent); }
.stat-box .lbl { font-size: 12px; color: var(--text-faint); margin-top: 4px; font-weight: 600; text-transform: uppercase; letter-spacing: .04em; }

.chart-wrap {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 24px;
}
.chart-wrap h3 { font-size: 16px; margin-bottom: 4px; }
.chart-wrap .sub { font-size: 13px; color: var(--text-faint); margin-bottom: 16px; }
canvas { display: block; width: 100%; height: 220px; }

.history-bars {
  display: flex;
  align-items: flex-end;
  gap: 4px;
  height: 80px;
  padding: 8px 0;
}
.history-bars .bar {
  flex: 1;
  background: var(--accent);
  border-radius: 3px 3px 0 0;
  min-height: 2px;
  position: relative;
  transition: var(--transition);
}
.history-bars .bar.empty { background: var(--bg-soft); }
.history-bars .bar.today { background: var(--flame); }

/* ---------- Settings screen ---------- */
.settings-group {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 16px;
}
.settings-group h3 { font-size: 14px; text-transform: uppercase; letter-spacing: .04em; color: var(--text-faint); margin-bottom: 14px; }
.setting-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}
.setting-row:last-child { border-bottom: none; }
.setting-row .s-label { font-weight: 600; }
.setting-row .s-desc { font-size: 13px; color: var(--text-faint); margin-top: 2px; }

/* Deck picker */
.deck-options { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 10px; }
.deck-opt {
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px;
  text-align: left;
  background: var(--bg);
  transition: var(--transition);
}
.deck-opt:hover { border-color: var(--accent); }
.deck-opt.active { border-color: var(--accent); background: var(--accent-soft); }
.deck-opt .icon { font-size: 22px; }
.deck-opt .title { font-weight: 700; margin-top: 6px; }
.deck-opt .desc { font-size: 12px; color: var(--text-faint); margin-top: 4px; line-height: 1.4; }

/* Segmented control */
.seg {
  display: inline-flex;
  background: var(--bg-soft);
  border-radius: var(--radius-sm);
  padding: 3px;
  gap: 2px;
}
.seg button {
  padding: 7px 14px;
  border-radius: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-soft);
  transition: var(--transition);
}
.seg button.active { background: var(--bg-elev); color: var(--accent); box-shadow: var(--shadow); }

/* Range */
input[type="range"] {
  width: 160px;
  accent-color: var(--accent);
}
.range-val { font-weight: 700; color: var(--accent); min-width: 50px; text-align: right; }

/* Danger button */
.btn-danger {
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--bad);
  color: var(--bad);
  font-weight: 600;
  font-size: 13px;
  transition: var(--transition);
}
.btn-danger:hover { background: var(--bad); color: white; }

.btn-primary {
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  background: var(--accent);
  color: var(--accent-text);
  font-weight: 700;
  font-size: 14px;
  transition: var(--transition);
}
.btn-primary:hover { filter: brightness(1.08); }

/* ---------- Modal ---------- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, .5);
  backdrop-filter: blur(4px);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 20px;
}
.modal-overlay.show { display: flex; animation: fade 200ms; }
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }
.modal {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  max-width: 520px;
  width: 100%;
  max-height: 80vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
}
.modal h2 { margin-bottom: 8px; }
.modal kbd {
  display: inline-block;
  padding: 2px 8px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 5px;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 600;
}
.shortcut-list { list-style: none; margin-top: 14px; }
.shortcut-list li {
  display: flex;
  justify-content: space-between;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
}
.shortcut-list li:last-child { border-bottom: none; }
.modal-close { margin-top: 18px; width: 100%; }

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--text);
  color: var(--bg);
  padding: 12px 20px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 600;
  box-shadow: var(--shadow-lg);
  z-index: 200;
  transition: transform 300ms cubic-bezier(.4, 0, .2, 1);
}
.toast.show { transform: translateX(-50%) translateY(0); }

/* ---------- Responsive ---------- */
@media (max-width: 600px) {
  #app { padding: 0 14px; }
  header { padding: 14px 0 10px; }
  .brand .name { font-size: 16px; }
  .stat-chip { padding: 5px 8px; font-size: 12px; }
  .header-actions { gap: 6px; }
  .icon-btn { width: 34px; height: 34px; }
  .answer-row { grid-template-columns: repeat(2, 1fr); }
  .card-face { padding: 24px 18px; min-height: 280px; }
  .ls-table th, .ls-table td { padding: 9px 10px; font-size: 13px; }
  .tab { padding: 7px 12px; font-size: 13px; }
}

/* RTL-ish: nothing needed */

/* tiny fade-in for screens */
.screen.active { animation: screenIn 250ms ease; }
@keyframes screenIn { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }

/* ---------- Verb forms block ---------- */
.card-forms {
  width: 100%;
  background: var(--bg-soft);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
}
.card-forms .forms-title {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--good);
  margin-bottom: 8px;
}
.card-forms .forms-row {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 6px;
}
.card-forms .form-cell {
  text-align: center;
  padding: 4px 2px;
}
.card-forms .form-tag {
  font-size: 10px;
  font-weight: 700;
  color: var(--text-faint);
}
.card-forms .form-word {
  font-size: 16px;
  font-weight: 700;
  margin: 2px 0;
  cursor: pointer;
  padding: 2px 4px;
  border-radius: 4px;
  transition: var(--transition);
}
.card-forms .form-word:hover { background: var(--accent-soft); color: var(--accent); }
.card-forms .form-label { font-size: 10px; color: var(--text-faint); }

/* verb-form card type color */
.card-type.verb-form { color: var(--good); }

/* ---------- Stats progress lines ---------- */
.stats-progress {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  margin-bottom: 16px;
}
.progress-line {
  display: grid;
  grid-template-columns: 130px 1fr 50px;
  align-items: center;
  gap: 12px;
  padding: 6px 0;
}
.progress-line + .progress-line { margin-top: 4px; }
.progress-line .pl-label { font-size: 14px; font-weight: 600; }
.progress-line .pl-bar {
  display: block;
  height: 10px;
  background: var(--bg-soft);
  border-radius: 999px;
  overflow: hidden;
}
.progress-line .pl-fill {
  display: block;
  height: 100%;
  background: var(--accent);
  border-radius: 999px;
  transition: width 500ms cubic-bezier(.4, 0, .2, 1);
}
.progress-line.mastered .pl-fill { background: var(--good); }
.progress-line.mastered .pl-label { color: var(--good); }
.progress-line .pl-num { font-weight: 700; text-align: right; font-size: 15px; }

.mastered-num { color: var(--good) !important; }

.stats-hint {
  font-size: 12px;
  color: var(--text-faint);
  text-align: center;
  margin-bottom: 24px;
  line-height: 1.6;
}

@media (max-width: 600px) {
  .progress-line { grid-template-columns: 110px 1fr 40px; gap: 8px; }
  .progress-line .pl-label { font-size: 13px; }
  .card-forms .forms-row { grid-template-columns: 1fr; gap: 2px; }
}