/* TypeWords — paper flashcard design system */

:root {
  --paper: #F7F4EE;
  --card: #FDFBF7;
  --raised: #EFE9DF;
  --ink: #1F1B16;
  --ink-2: #5E554A;
  --ink-3: #736A5E;
  --line: rgba(31, 27, 22, 0.09);
  --line-strong: rgba(31, 27, 22, 0.16);
  --accent: #92400E;
  --positive: #4E7A3A;
  --negative: #B0403A;
  --radius-control: 8px;
  --radius-card: 12px;
  --radius-panel: 16px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-serif: "Songti SC", "STSong", "Noto Serif CJK SC", "Source Han Serif SC", SimSun, serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", "SFMono-Regular", Consolas, "Cascadia Mono", monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html, body { height: 100%; }

body {
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 1.5;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  height: 100dvh;
  overflow: hidden;
}

button, input, select { font-family: inherit; font-size: inherit; color: inherit; }
button { cursor: pointer; }
button:disabled { cursor: not-allowed; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.sprite { position: absolute; width: 0; height: 0; overflow: hidden; }

.icon {
  width: 16px;
  height: 16px;
  flex: none;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* ---------- shell ---------- */

.app-container { display: flex; height: 100dvh; width: 100%; }

.sidebar {
  width: 256px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  background: var(--card);
  border-right: 1px solid var(--line);
}
.sidebar.collapsed { width: 64px; }

.sidebar-head {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 24px 20px 20px;
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 8px; white-space: nowrap; }
.brand-mark { width: 20px; height: 20px; flex: none; }
.brand-name { font-size: 17px; font-weight: 500; letter-spacing: 0.01em; }

.lib-selector { display: flex; flex-direction: column; gap: 8px; }
.field-label { font-size: 12px; color: var(--ink-3); }
.lib-selector select {
  width: 100%;
  height: 36px;
  padding: 0 32px 0 12px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-control);
  background-color: var(--card);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%235E554A' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 12px;
  font-size: 13px;
  font-weight: 500;
  outline: none;
  appearance: none;
  transition: border-color 140ms var(--ease);
}
.lib-selector select:hover { border-color: var(--ink-3); }
.lib-selector select:focus-visible { border-color: var(--accent); }

.sidebar nav { display: flex; flex-direction: column; gap: 4px; flex: 1; padding: 24px 12px 16px; }
.nav-btn {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  height: 36px;
  padding: 0 12px;
  border: 0;
  border-radius: var(--radius-control);
  background: transparent;
  color: var(--ink-2);
  font-size: 14px;
  text-align: left;
  white-space: nowrap;
  transition: background-color 140ms var(--ease), color 140ms var(--ease);
}
.nav-btn:hover { background: var(--paper); color: var(--ink); }
.nav-btn.active { background: var(--raised); color: var(--ink); font-weight: 500; box-shadow: inset 2px 0 0 var(--accent); }
.icon-box { display: flex; justify-content: center; width: 18px; flex: none; }

.toggle-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  height: 36px;
  margin: 0 12px 16px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius-control);
  background: transparent;
  color: var(--ink-3);
  font-size: 12px;
  transition: background-color 140ms var(--ease);
}
.toggle-btn:hover { background: var(--paper); }
.toggle-btn .icon { transition: transform 180ms var(--ease); }

.sidebar.collapsed .sidebar-head { align-items: center; padding: 20px 12px; }
.sidebar.collapsed .brand-name,
.sidebar.collapsed .lib-selector { display: none; }
.sidebar.collapsed nav { padding: 24px 8px 16px; }
.sidebar.collapsed .nav-btn { justify-content: center; padding: 0; }
.sidebar.collapsed .nav-btn .text { display: none; }
.sidebar.collapsed .toggle-btn { justify-content: center; padding: 0; margin: 0 8px 16px; }
.sidebar.collapsed .toggle-btn .text { display: none; }
.sidebar.collapsed .toggle-btn .icon { transform: rotate(180deg); }

.main-content { flex: 1; min-width: 0; overflow-y: auto; padding: 32px; }
.view {
  display: none;
  width: 100%;
  max-width: 1440px;
  min-height: 100%;
  margin: 0 auto;
  flex-direction: column;
  gap: 24px;
}
.view.active { display: flex; }

/* ---------- progress strip ---------- */

.top-nav-area { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 16px; }
.word-nav { display: flex; gap: 8px; min-width: 0; }
.word-nav-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  height: 36px;
  max-width: 200px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius-control);
  background: var(--card);
  color: var(--ink-3);
  font-size: 13px;
  transition: background-color 140ms var(--ease), border-color 140ms var(--ease);
}
.word-nav-btn span { min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; color: var(--ink-2); font-weight: 500; }
.word-nav-btn:hover:not(:disabled) { background: var(--raised); border-color: var(--line-strong); }
.word-nav-btn:disabled { opacity: 0.45; }

.stats { display: flex; align-items: center; gap: 24px; }
.stat { display: flex; align-items: baseline; gap: 8px; }
.stat-label { font-size: 12px; color: var(--ink-3); }
.stat-value { font-family: var(--font-mono); font-size: 14px; font-weight: 500; font-variant-numeric: tabular-nums; color: var(--ink-2); }
.stat--daily .stat-value { color: var(--accent); }
.daily-track { width: 96px; height: 3px; border-radius: 2px; background: var(--raised); overflow: hidden; }
.daily-fill { width: 100%; height: 100%; background: var(--accent); transform: scaleX(var(--progress, 0)); transform-origin: left; transition: transform 320ms var(--ease); }

/* ---------- practice stage ---------- */

.practice-stage {
  flex: 1;
  min-height: 360px;
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  overflow: hidden;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-panel);
  animation: rise 320ms var(--ease) both;
}
.stage-left, .stage-right { display: flex; flex-direction: column; min-width: 0; padding: 32px; }
.stage-left { background: var(--paper); border-right: 1px solid var(--line); }
.pane-label { flex: none; font-size: 12px; color: var(--ink-3); }
.stage-body { display: flex; flex-direction: column; gap: 16px; margin-block: auto; }
.stage-answer { display: flex; flex-direction: column; gap: 24px; margin-block: auto; }
.stage-foot { display: flex; align-items: center; gap: 8px; flex: none; font-size: 12px; color: var(--ink-3); }
.stage-foot kbd {
  padding: 4px 6px;
  border: 1px solid var(--line); border-bottom-color: var(--line-strong); border-radius: 4px;
  background: var(--card); color: var(--ink-2);
  font-family: var(--font-mono); font-size: 11px; line-height: 1;
}
.foot-sep { color: var(--line-strong); }

.stage-kicker { display: flex; align-items: center; gap: 8px; font-size: 12px; color: var(--ink-3); }
.stage-kicker::before { content: ""; width: 6px; height: 6px; border-radius: 50%; border: 1px solid var(--ink-3); }
.stage-kicker[data-mode="review"]::before { background: var(--negative); border-color: var(--negative); }

.meaning { font-family: var(--font-serif); font-size: 40px; font-weight: 500; line-height: 1.25; color: var(--ink); word-break: break-word; }
.meta-row { display: flex; align-items: center; gap: 12px; min-height: 36px; }
.phonetic { font-family: var(--font-mono); font-size: 14px; color: var(--ink-2); }
.phonetic:empty { display: none; }
.speak-btn {
  display: flex; align-items: center; justify-content: center;
  width: 36px; height: 36px;
  border: 1px solid var(--line); border-radius: var(--radius-control);
  background: var(--card); color: var(--ink-2);
  transition: background-color 140ms var(--ease);
}
.speak-btn:hover { background: var(--raised); }

.stage-steps { display: flex; align-items: center; gap: 8px; font-size: 12px; color: var(--ink-3); }
.stage-steps .step { padding-bottom: 4px; border-bottom: 1px solid transparent; }
.stage-steps .step + .step::before { content: "→"; margin-right: 8px; color: var(--line-strong); }
.stage-steps[data-stage="1"] .step:nth-child(1),
.stage-steps[data-stage="2"] .step:nth-child(2),
.stage-steps[data-stage="3"] .step:nth-child(3) { color: var(--ink); border-bottom-color: var(--accent); }

.word-zone { position: relative; width: 100%; min-height: 64px; display: flex; align-items: center; }
.slots { display: flex; flex-wrap: wrap; gap: 8px; }
.slot {
  position: relative;
  width: 48px; height: 56px;
  display: flex; align-items: center; justify-content: center;
  border: 1px solid var(--line);
  border-bottom: 2px solid var(--line-strong);
  border-radius: 6px;
  background: var(--card);
  font-family: var(--font-mono);
  font-size: 28px; font-weight: 500; line-height: 1;
  font-variant-numeric: tabular-nums;
  color: var(--ink);
}
.slot.slot-space { background: transparent; border-color: transparent; color: var(--ink-3); }
.slot.slot-hint { color: #B4A796; }
.slot.typing { color: var(--ink); border-bottom-color: var(--ink-2); }
.slot.correct { color: var(--positive); border-bottom-color: var(--positive); }
.slot.wrong { color: var(--negative); border-bottom-color: var(--negative); }
.slot.active { border-bottom-color: var(--ink-2); }
.slot.active::after {
  content: "";
  position: absolute;
  left: 4px; right: 4px; bottom: -7px;
  height: 2px;
  background: var(--accent);
  border-radius: 60% 40% 55% 45% / 100% 100% 60% 80%;
  transform: rotate(-1deg);
}

.hidden-input {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.01;
  border: none;
  outline: none;
  cursor: pointer;
  z-index: 10;
  font-size: 16px;
  color: transparent;
  background: transparent;
  caret-color: transparent;
  -webkit-appearance: none;
  appearance: none;
  border-radius: 0;
}

.hint { font-size: 13px; color: var(--ink-3); min-height: 20px; }
.hint[data-tone="correct"] { color: var(--positive); }
.hint[data-tone="wrong"] { color: var(--negative); }
.hint[data-tone="accent"] { color: var(--accent); }

/* ---------- controls ---------- */

.actions { display: flex; gap: 12px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  height: 44px; min-width: 120px; padding: 0 20px;
  border: 1px solid var(--line-strong); border-radius: var(--radius-control);
  background: var(--card); color: var(--ink);
  font-size: 14px; font-weight: 500;
  transition: background-color 140ms var(--ease), border-color 140ms var(--ease), color 140ms var(--ease), transform 140ms var(--ease);
}
.btn:hover:not(:disabled) { background: var(--raised); }
.btn:active:not(:disabled) { transform: scale(0.98); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #FFFDF8; }
.btn.primary:hover:not(:disabled) { background: #7C370C; border-color: #7C370C; }
.btn.primary:disabled { background: var(--raised); border-color: var(--line); color: var(--ink-3); }
.actions .btn { flex: 1 1 0; max-width: 200px; }

/* ---------- lists ---------- */

.view-title { font-family: var(--font-serif); font-size: 28px; font-weight: 500; color: var(--ink); }
.view-desc { font-size: 13px; color: var(--ink-3); }
.view-toolbar { display: flex; flex-wrap: wrap; gap: 8px; }
.list-container { display: flex; flex-direction: column; gap: 8px; }
.list-container--scroll { max-height: 60vh; overflow-y: auto; }
.list-item {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 16px 20px;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius-card);
}
.list-info { display: flex; flex-direction: column; gap: 4px; min-width: 0; }
.list-word { font-family: var(--font-mono); font-size: 15px; font-weight: 500; color: var(--ink); }
.list-phonetic { margin-left: 8px; font-size: 12px; font-weight: 400; color: var(--ink-3); }
.list-meaning { font-size: 13px; color: var(--ink-2); }
.list-actions { display: flex; gap: 8px; flex: none; }
.icon-btn {
  display: inline-flex; align-items: center; justify-content: center;
  width: 36px; height: 36px;
  border: 1px solid var(--line); border-radius: var(--radius-control);
  background: var(--card); color: var(--ink-2);
  transition: background-color 140ms var(--ease), color 140ms var(--ease), border-color 140ms var(--ease);
}
.icon-btn:hover { background: var(--raised); }
.btn-delete:hover { color: var(--negative); border-color: var(--negative); }
.empty { padding: 40px 16px; text-align: center; font-size: 13px; color: var(--ink-3); }

/* ---------- settings ---------- */

.modal-overlay {
  position: fixed; inset: 0;
  background: rgba(31, 27, 22, 0.36);
  display: none; align-items: center; justify-content: center;
  z-index: 1000; padding: 16px;
}
.modal-overlay.show { display: flex; animation: fade 200ms var(--ease) both; }
.modal-content {
  width: 100%; max-width: 420px; padding: 24px;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius-panel);
  box-shadow: 0 8px 24px rgba(31, 27, 22, 0.10);
  animation: rise 200ms var(--ease) both;
}
.modal-title { font-family: var(--font-serif); font-size: 20px; font-weight: 500; margin-bottom: 24px; }
.form-group { display: flex; flex-direction: column; gap: 8px; margin-bottom: 20px; }
.form-group label { font-size: 12px; color: var(--ink-3); }
.form-group input, .text-input {
  width: 100%; height: 40px; padding: 0 12px;
  border: 1px solid var(--line-strong); border-radius: var(--radius-control);
  background: var(--card); font-size: 14px; outline: none;
  transition: border-color 140ms var(--ease);
}
.form-group input:focus, .text-input:focus { border-color: var(--accent); }
.sync-section { display: flex; flex-direction: column; gap: 12px; padding-top: 20px; border-top: 1px solid var(--line); }
.sync-section .field-label { line-height: 1.4; }
.sync-row { display: flex; gap: 8px; }
.sync-row .text-input { flex: 1; min-width: 0; font-family: var(--font-mono); font-size: 12px; }
.sync-row .text-input[readonly] { background: var(--raised); color: var(--ink-2); }
.sync-row .btn { flex: none; height: 40px; min-width: 0; padding: 0 12px; font-size: 13px; }
.modal-actions { display: flex; gap: 12px; margin-top: 24px; }
.modal-actions .btn { flex: 1; }
.danger-zone { margin-top: 24px; padding-top: 20px; border-top: 1px solid var(--line); }
.danger-btn {
  display: flex; align-items: center; justify-content: center; gap: 8px;
  width: 100%; height: 44px;
  border: 1px solid var(--line); border-radius: var(--radius-control);
  background: transparent; color: var(--negative); font-size: 13px;
  transition: background-color 140ms var(--ease), border-color 140ms var(--ease);
}
.danger-btn:hover { background: rgba(176, 64, 58, 0.06); border-color: var(--negative); }

@keyframes rise { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }

/* ---------- mobile ---------- */

@media (max-width: 768px) {
  .app-container { flex-direction: column; }
  .sidebar, .sidebar.collapsed { width: 100%; height: auto; flex-direction: column; border-right: none; border-bottom: 1px solid var(--line); }
  .sidebar-head, .sidebar.collapsed .sidebar-head { flex-direction: row; align-items: center; justify-content: space-between; gap: 12px; padding: 8px 16px; }
  .brand-name, .sidebar.collapsed .brand-name { display: inline; font-size: 15px; }
  .lib-selector, .sidebar.collapsed .lib-selector { display: flex; flex-direction: row; align-items: center; gap: 8px; }
  .lib-selector .field-label { display: none; }
  .lib-selector select { width: auto; max-width: 160px; height: 32px; padding: 0 28px 0 10px; font-size: 12px; background-position: right 8px center; }

  .sidebar nav, .sidebar.collapsed nav { flex-direction: row; gap: 0; padding: 0; }
  .nav-btn, .sidebar.collapsed .nav-btn {
    flex: 1 1 0; min-width: 0; height: 56px;
    flex-direction: column; gap: 4px; justify-content: center; padding: 0 4px;
    border-radius: 0; font-size: 12px;
  }
  .nav-btn .icon-box, .sidebar.collapsed .nav-btn .icon-box { width: auto; }
  .nav-btn .text, .sidebar.collapsed .nav-btn .text { display: block; font-size: 11px; white-space: nowrap; }
  .nav-btn.active, .sidebar.collapsed .nav-btn.active { box-shadow: inset 0 -2px 0 var(--accent); }
  .toggle-btn, .sidebar.collapsed .toggle-btn { display: none; }

  .main-content { padding: 16px; }
  .view { gap: 16px; }
  .top-nav-area { gap: 12px; }
  .word-nav { width: 100%; }
  .word-nav-btn { flex: 1 1 0; min-width: 0; max-width: none; }
  .stats { width: 100%; flex-wrap: wrap; gap: 8px 20px; }
  .daily-track { flex: 1 1 100%; width: 100%; }

  .practice-stage { grid-template-columns: 1fr; gap: 24px; padding: 24px 16px; min-height: 0; align-content: center; grid-auto-rows: auto; }
  .stage-left, .stage-right { padding: 0; background: transparent; border-right: none; }
  .pane-label, .stage-foot { display: none; }
  .stage-body { gap: 12px; margin-block: 0; }
  .stage-answer { gap: 20px; margin-block: 0; }
  .meaning { font-size: 28px; }
  .slots { justify-content: center; gap: 4px; }
  .slot { width: clamp(26px, 8vw, 36px); height: 44px; font-size: 18px; }
  .actions .btn { flex: 1 1 0; max-width: none; min-width: 0; }
  .modal-content { max-width: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}