:root {
  --bg: #faf8f4;
  --bg-alt: #f0ece2;
  --card: #ffffff;
  --text: #2b2621;
  --text-dim: #756e63;
  --border: #ddd5c7;
  --accent: #7a4a2b;
  --accent-dim: #a9754f;
  --good: #3f7d4f;
  --bad: #b3452f;
  --warn: #c8952c;
  --radius: 10px;
  --greek-font: "Gentium Plus", "Cardo", "Noto Serif", "Palatino Linotype", "Times New Roman", serif;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #1c1a17;
    --bg-alt: #262320;
    --card: #2a2622;
    --text: #ece6db;
    --text-dim: #a99f8f;
    --border: #423c34;
    --accent: #d9a066;
    --accent-dim: #b17f4d;
    --good: #6fbf80;
    --bad: #e07a63;
    --warn: #e0b95a;
  }
}

:root[data-theme="dark"] {
  --bg: #1c1a17;
  --bg-alt: #262320;
  --card: #2a2622;
  --text: #ece6db;
  --text-dim: #a99f8f;
  --border: #423c34;
  --accent: #d9a066;
  --accent-dim: #b17f4d;
  --good: #6fbf80;
  --bad: #e07a63;
  --warn: #e0b95a;
}

* { box-sizing: border-box; }

/* Without this, mobile browsers delay (sometimes effectively swallow)
   the first tap on an element while they check whether it's the start
   of a double-tap-to-zoom gesture — every clickable thing in the app
   needs it, not just the drag/match pieces. */
button, .chip, td.drop-target, .mcq-option {
  touch-action: manipulation;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

.greek { font-family: var(--greek-font); }

.topbar {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 0.75rem 1.25rem;
  background: var(--card);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: env(safe-area-inset-top, 0px);
  z-index: 10;
  flex-wrap: wrap;
}

.brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--accent);
  white-space: nowrap;
}

.tabs { display: flex; gap: 0.25rem; flex-wrap: wrap; }

.tab {
  background: none;
  border: 1px solid transparent;
  color: var(--text-dim);
  padding: 0.4rem 0.8rem;
  border-radius: 999px;
  cursor: pointer;
  font-size: 0.9rem;
}

.tab:hover { background: var(--bg-alt); }

.tab.active {
  background: var(--accent);
  color: white;
  font-weight: 600;
}

main#app {
  max-width: 860px;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 4rem;
}

.loading { text-align: center; color: var(--text-dim); padding: 3rem 0; }

h1, h2, h3 { color: var(--text); }
h1 { font-size: 1.4rem; margin-top: 0; }
h2 { font-size: 1.15rem; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  margin-bottom: 1rem;
}

.btn {
  background: var(--accent);
  color: white;
  border: none;
  padding: 0.55rem 1.1rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.95rem;
  font-weight: 600;
}
.btn:hover { background: var(--accent-dim); }
.btn.secondary {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}
.btn.secondary:hover { background: var(--bg-alt); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.row { display: flex; gap: 0.6rem; flex-wrap: wrap; align-items: center; }
.row.between { justify-content: space-between; }

.pill {
  display: inline-block;
  padding: 0.15rem 0.6rem;
  border-radius: 999px;
  background: var(--bg-alt);
  color: var(--text-dim);
  font-size: 0.78rem;
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 0.75rem;
  margin: 1rem 0;
}
.stat-tile {
  background: var(--bg-alt);
  border-radius: var(--radius);
  padding: 0.9rem;
  text-align: center;
}
.stat-tile .num { font-size: 1.6rem; font-weight: 700; color: var(--accent); }
.stat-tile .label { font-size: 0.78rem; color: var(--text-dim); }

.bar-row { display: flex; align-items: center; gap: 0.6rem; margin: 0.4rem 0; }
.bar-label { width: 220px; font-size: 0.85rem; flex-shrink: 0; }
.bar-track {
  flex: 1;
  height: 14px;
  background: var(--bg-alt);
  border-radius: 7px;
  overflow: hidden;
}
.bar-fill { height: 100%; border-radius: 7px; }
.bar-pct { width: 42px; font-size: 0.8rem; text-align: right; color: var(--text-dim); }

input[type="text"], input[type="number"] {
  font-size: 1rem;
  padding: 0.5rem 0.6rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font-family: var(--greek-font);
}

input[type="range"] { width: 100%; }

table.paradigm {
  display: block;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border-collapse: collapse;
  width: 100%;
  max-width: 100%;
  margin: 0.75rem 0;
  font-size: 0.95rem;
}
table.paradigm tbody, table.paradigm thead {
  display: table;
  width: 100%;
}
table.paradigm th, table.paradigm td {
  border: 1px solid var(--border);
  padding: 0.35rem 0.5rem;
  text-align: center;
}
table.paradigm th { background: var(--bg-alt); font-size: 0.78rem; }
table.paradigm td.label { font-weight: 600; background: var(--bg-alt); }
table.paradigm .greek { font-size: 1.05rem; }
table.paradigm input.blank {
  width: 100%;
  min-width: 60px;
  text-align: center;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.2rem;
}
table.paradigm input.blank.correct { border-color: var(--good); background: color-mix(in srgb, var(--good) 15%, var(--card)); }
table.paradigm input.blank.incorrect { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 15%, var(--card)); }

.flash-front, .flash-back {
  text-align: center;
  padding: 2rem 1rem;
}
.flash-front .greek, .flash-back .greek { font-size: 2.2rem; }
.flash-meta { color: var(--text-dim); font-size: 0.85rem; margin-top: 0.5rem; }

.grade-row { display: flex; gap: 0.5rem; justify-content: center; margin-top: 1rem; flex-wrap: wrap; }
.grade-btn {
  flex: 1;
  min-width: 80px;
  padding: 0.6rem;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  color: white;
  font-weight: 600;
}
.grade-btn.again { background: var(--bad); }
.grade-btn.hard { background: var(--warn); }
.grade-btn.good { background: var(--good); }
.grade-btn.easy { background: var(--accent); }

.mcq-options { display: grid; gap: 0.5rem; margin-top: 1rem; }
.mcq-option {
  text-align: left;
  padding: 0.7rem 1rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  cursor: pointer;
  font-size: 1rem;
}
.mcq-option:hover { background: var(--bg-alt); }
.mcq-option.correct { border-color: var(--good); background: color-mix(in srgb, var(--good) 18%, var(--card)); }
.mcq-option.incorrect { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 18%, var(--card)); }

.greek-kbd {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin: 0.6rem 0;
  padding: 0.6rem;
  background: var(--bg-alt);
  border-radius: 8px;
}
.greek-kbd button {
  font-family: var(--greek-font);
  font-size: 1rem;
  padding: 0.35rem 0.5rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  cursor: pointer;
  min-width: 2.1rem;
}
.greek-kbd button:hover { background: var(--accent); color: white; }
.greek-kbd .kbd-group-label { width: 100%; font-size: 0.72rem; color: var(--text-dim); margin-top: 0.3rem; }

.feedback {
  margin-top: 0.75rem;
  padding: 0.6rem 0.9rem;
  border-radius: 8px;
  font-size: 0.95rem;
}
.feedback.correct { background: color-mix(in srgb, var(--good) 20%, var(--card)); color: var(--good); }
.feedback.incorrect { background: color-mix(in srgb, var(--bad) 20%, var(--card)); color: var(--bad); }

.chapter-list { display: flex; flex-direction: column; gap: 0.4rem; margin-top: 0.5rem; }
.chapter-item {
  display: flex;
  justify-content: space-between;
  padding: 0.5rem 0.75rem;
  border-radius: 8px;
  background: var(--bg-alt);
}
.chapter-item.locked { opacity: 0.45; }

.reference-text {
  white-space: pre-wrap;
  font-family: var(--greek-font);
  font-size: 0.95rem;
  line-height: 1.5;
  background: var(--bg-alt);
  border-radius: 8px;
  padding: 1rem;
  max-height: 480px;
  overflow-y: auto;
}

td.drop-target {
  min-width: 70px;
  height: 2.4rem;
  border: 2px dashed var(--border);
  border-radius: 6px;
  text-align: center;
  vertical-align: middle;
}
td.drop-target.hover { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 12%, var(--card)); }
td.drop-target.filled { border-style: solid; border-color: var(--good); background: color-mix(in srgb, var(--good) 12%, var(--card)); }
td.drop-target .placed-chip { font-family: var(--greek-font); font-size: 1.05rem; }

.chip-bank {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 0.75rem;
  background: var(--bg-alt);
  border-radius: var(--radius);
  min-height: 3rem;
  margin: 0.75rem 0;
}
.chip {
  font-family: var(--greek-font);
  font-size: 1.05rem;
  padding: 0.4rem 0.8rem;
  border-radius: 8px;
  background: var(--card);
  border: 1px solid var(--border);
  cursor: grab;
  user-select: none;
}
.chip:active { cursor: grabbing; }

/* iOS Safari decides whether a non-native element (a div/td with only a
   JS click listener, no real <button>/<a>) is "clickable" partly from its
   cursor style. Without cursor:pointer, the first tap just simulates
   hover/focus and a second tap is needed to actually fire the click —
   which is exactly the "tap twice" symptom on the match games. Scoped to
   coarse-pointer (touchscreen) so desktop keeps the grab/pointer cursors
   that make sense for a mouse. */
@media (pointer: coarse) {
  .chip, td.drop-target {
    cursor: pointer;
  }
}
.chip.dragging { opacity: 0.4; }
.chip.selected { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 20%, var(--card)); box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent) 40%, transparent); }
.chip.wrong-shake { animation: shake 0.3s; border-color: var(--bad); }
@keyframes shake {
  25% { transform: translateX(-4px); }
  75% { transform: translateX(4px); }
}

textarea.import-box {
  width: 100%;
  min-height: 100px;
  font-family: monospace;
  font-size: 0.8rem;
}