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

:root {
  --ink: #1a1208;
  --paper: #f5efe3;
  --red: #c0392b;
  --gold: #b8960c;
  --muted: #7a6e5f;
  --border: #d4c8b0;
  --card-bg: #faf6ee;

  --shadow: rgba(26,18,8,0.09);
  --overlay: rgba(26,18,8,0.85);
  --speaking-bg: #fff8e6;
  --hint-bg: #fff4da;
  --gradient-red: rgba(192,57,43,0.06);
  --gradient-gold: rgba(184,150,12,0.07);
  --intro-gradient: linear-gradient(135deg, rgba(192,57,43,0.08) 0%, rgba(184,150,12,0.06) 100%);
  --lang-shadow: rgba(26,18,8,0.08);
  --focus-ring: rgba(192,57,43,0.12);

  /* System font stacks - no external fonts needed */
  --font-hanzi: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Heiti SC", system-ui, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Menlo", "Monaco", monospace;
  --font-serif: "New York", "Iowan Old Style", Georgia, serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Text", system-ui, sans-serif;
}

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-mono);
  min-height: 100vh;
  padding: calc(env(safe-area-inset-top) + 2rem) calc(env(safe-area-inset-right) + 1rem) calc(env(safe-area-inset-bottom) + 4rem) calc(env(safe-area-inset-left) + 1rem);
  background-image:
    radial-gradient(ellipse at 10% 0%, var(--gradient-red) 0%, transparent 50%),
    radial-gradient(ellipse at 90% 100%, var(--gradient-gold) 0%, transparent 50%);
  -webkit-tap-highlight-color: transparent;
  -webkit-touch-callout: none;
}

header {
  text-align: center;
  margin-bottom: 3rem;
  position: relative;
}

.header-rule {
  width: 60px;
  height: 3px;
  background: var(--red);
  margin: 0 auto 1.2rem;
}

h1 {
  font-family: var(--font-hanzi);
  font-size: clamp(2.2rem, 6vw, 3.5rem);
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--ink);
  line-height: 1.1;
}

.subtitle {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 1rem;
  color: var(--muted);
  margin-top: 0.6rem;
  letter-spacing: 0.03em;
}

.section {
  max-width: 860px;
  margin: 0 auto 2.8rem;
}

.subsection-title {
  max-width: 860px;
  margin: 0 auto 1.5rem;
  font-family: var(--font-hanzi);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--ink);
  padding: 0 0 0.6rem;
  border-bottom: 1px solid var(--ink);
  position: relative;
}
.subsection-title::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 60px;
  height: 3px;
  background: var(--red);
}
.subsection-title + .section { margin-top: 0; }
.subsection:not(:first-child) .subsection-title {
  margin-top: 1rem;
}

.section-title {
  font-family: var(--font-hanzi);
  font-size: 0.7rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--red);
  border-left: 3px solid var(--red);
  padding-left: 0.75rem;
  margin-bottom: 1rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 0.75rem;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1rem 1.1rem;
  position: relative;
  transition: transform 0.15s, box-shadow 0.15s;
  cursor: pointer;
  overflow: hidden;
  user-select: none;
}

.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 3px; height: 100%;
  background: var(--gold);
  opacity: 0;
  transition: opacity 0.2s;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--shadow);
}
.card:hover::before { opacity: 1; }

.card:active { transform: translateY(0); }

.card.speaking {
  background: var(--speaking-bg);
  border-color: var(--gold);
}
.card.speaking::before { opacity: 1; }

.speaker {
  position: absolute;
  top: 0.6rem;
  right: 0.6rem;
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0.35;
  transition: opacity 0.15s;
  color: var(--muted);
}
.card:hover .speaker { opacity: 0.8; }
.card.speaking .speaker { opacity: 1; color: var(--red); }
.speaker svg { width: 14px; height: 14px; }

.favorite-btn {
  position: absolute;
  top: 0.6rem;
  left: 0.6rem;
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  padding: 0;
  margin: 0;
  cursor: pointer;
  color: var(--muted);
  opacity: 0.35;
  transition: opacity 0.15s, color 0.15s;
  -webkit-tap-highlight-color: transparent;
}
.card:hover .favorite-btn,
.phrase-card:hover .favorite-btn { opacity: 0.8; }
.favorite-btn svg { width: 16px; height: 16px; fill: none; stroke: currentColor; stroke-width: 2; }
.favorite-btn.active { opacity: 1; color: var(--gold); }
.favorite-btn.active svg { fill: var(--gold); stroke: var(--gold); }
.phrase-card .favorite-btn { top: 0.75rem; left: 0.75rem; }

.hanzi {
  font-family: var(--font-hanzi);
  font-size: 2rem;
  font-weight: 700;
  color: var(--ink);
  line-height: 1;
  margin-bottom: 0.35rem;
  padding-left: 1.8rem;
}

.pinyin {
  font-size: 0.72rem;
  color: var(--red);
  letter-spacing: 0.08em;
  margin-bottom: 0.3rem;
  font-weight: 500;
}

.meaning {
  font-size: 0.78rem;
  color: var(--muted);
  font-family: var(--font-serif);
  font-style: italic;
}

.tip-box {
  max-width: 860px;
  margin: 0 auto;
  background: var(--ink);
  color: var(--paper);
  border-radius: 4px;
  padding: 1.2rem 1.5rem;
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  font-size: 0.78rem;
  line-height: 1.7;
}
.tip-box .icon { font-size: 1.3rem; flex-shrink: 0; }
.tip-box strong { color: var(--gold); }

@media (max-width: 500px) {
  .grid { grid-template-columns: 1fr 1fr; }
  .phrase-grid { grid-template-columns: 1fr; }
}

/* Phrase cards - wider, different layout */
.phrase-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 0.75rem;
}

.phrase-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-left: 3px solid var(--gold);
  border-radius: 4px;
  padding: 1rem 1.2rem;
  position: relative;
  transition: transform 0.15s, box-shadow 0.15s;
  cursor: pointer;
  overflow: hidden;
  user-select: none;
}

.phrase-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--shadow);
  border-left-color: var(--red);
}
.phrase-card:active { transform: translateY(0); }
.phrase-card.speaking {
  background: var(--speaking-bg);
  border-left-color: var(--red);
}

.phrase-hanzi {
  font-family: var(--font-hanzi);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--ink);
  line-height: 1.3;
  margin-bottom: 0.35rem;
  padding-right: 1.8rem;
  padding-left: 1.8rem;
}

.phrase-pinyin {
  font-size: 0.72rem;
  color: var(--red);
  letter-spacing: 0.06em;
  margin-bottom: 0.4rem;
  font-weight: 500;
}

.phrase-meaning {
  font-size: 0.8rem;
  color: var(--muted);
  font-family: var(--font-serif);
  font-style: italic;
  line-height: 1.4;
}

.phrase-card .speaker {
  top: 0.75rem;
  right: 0.75rem;
}

/* Tabs */
.tabs {
  max-width: 860px;
  margin: 0 auto 2rem;
  display: flex;
  gap: 0.3rem;
  padding: 0.3rem;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.tab {
  flex: 1 1 auto;
  min-width: 0;
  background: transparent;
  border: none;
  padding: 0.5rem 0.4rem;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  cursor: pointer;
  border-radius: 4px;
  transition: all 0.2s;
  font-weight: 500;
  text-align: center;
  white-space: nowrap;
}

.tab:hover { color: var(--ink); }

.tab.active {
  background: var(--ink);
  color: var(--paper);
}

.tab .tab-hanzi {
  font-family: var(--font-hanzi);
  margin-right: 0.25rem;
  font-size: 0.85rem;
  letter-spacing: 0;
  display: block;
}

.tab-panel { display: none; }
.tab-panel.active { display: block; animation: fadeIn 0.25s ease-out; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Install hint banner (shown on iOS/Android, not when standalone or dismissed) */
.install-hint {
  max-width: 860px;
  margin: 0 auto 1.5rem;
  background: var(--hint-bg);
  border: 1px solid var(--gold);
  border-radius: 6px;
  padding: 0.85rem 1rem;
  font-size: 0.78rem;
  color: var(--ink);
  line-height: 1.5;
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
  position: relative;
}
.install-hint strong { color: var(--red); }
.install-hint .close-hint {
  position: absolute;
  top: 0.5rem; right: 0.6rem;
  background: transparent;
  border: none;
  font-size: 1rem;
  color: var(--muted);
  cursor: pointer;
  padding: 0.2rem 0.4rem;
}
.install-hint .install-btn {
  flex-shrink: 0;
  align-self: center;
  background: var(--ink);
  color: var(--paper);
  border: none;
  border-radius: 4px;
  padding: 0.35rem 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  cursor: pointer;
  white-space: nowrap;
  -webkit-tap-highlight-color: transparent;
}
.install-hint .install-btn:hover { background: var(--red); }
/* Hide when in standalone mode */
@media (display-mode: standalone) {
  .install-hint { display: none !important; }
}

.favorites-empty {
  max-width: 860px;
  margin: 0 auto;
  padding: 3rem 1rem;
  text-align: center;
  font-family: var(--font-serif);
  font-style: italic;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

.load-error {
  max-width: 860px;
  margin: 0 auto;
  padding: 1rem;
  color: var(--red);
  font-size: 0.85rem;
  text-align: center;
}

.lang-switch {
  position: fixed;
  top: calc(env(safe-area-inset-top) + 0.75rem);
  right: calc(env(safe-area-inset-right) + 0.75rem);
  z-index: 100;
  display: flex;
  gap: 0.1rem;
  padding: 0.2rem;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 999px;
  box-shadow: 0 2px 8px var(--lang-shadow);
}
.lang-switch button {
  background: transparent;
  border: none;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--muted);
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
  -webkit-tap-highlight-color: transparent;
}
.lang-switch button:hover { color: var(--ink); }
.lang-switch button.active {
  background: var(--ink);
  color: var(--paper);
}

.app-version {
  position: fixed;
  bottom: calc(env(safe-area-inset-bottom) + 0.6rem);
  right: calc(env(safe-area-inset-right) + 0.9rem);
  z-index: 100;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--muted);
  letter-spacing: 0.1em;
  opacity: 0.55;
  pointer-events: none;
  user-select: none;
}

.search-wrap {
  position: relative;
  max-width: 860px;
  margin: 0 auto 1.2rem;
  display: flex;
  justify-content: center;
}

.toolbar {
  max-width: 860px;
  margin: 0 auto 1.2rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.search-input {
  flex: 1;
  max-width: 260px;
  padding: 0.42rem 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--ink);
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 999px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
  -webkit-appearance: none;
}

.search-input:focus {
  border-color: var(--red);
  box-shadow: 0 0 0 2px var(--focus-ring);
}

.search-input::placeholder { color: var(--muted); opacity: 0.7; }

/* remove native clear button on webkit */
.search-input::-webkit-search-cancel-button { -webkit-appearance: none; }

.search-field {
  position: relative;
  display: flex;
  align-items: center;
}

.search-input { padding-right: 1.6rem; }

.search-clear {
  position: absolute;
  right: 0.55rem;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  cursor: pointer;
  color: var(--muted);
  font-size: 0.8rem;
  line-height: 1;
  padding: 0.2rem 0.3rem;
  border-radius: 50%;
  transition: color 0.15s;
}
.search-clear:hover { color: var(--ink); }

.fav-btn {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 50%;
  cursor: pointer;
  color: var(--muted);
  transition: all 0.2s;
}

.fav-btn:hover, .fav-btn.active {
  color: var(--gold);
  border-color: var(--gold);
}

.fav-btn svg {
  width: 18px;
  height: 18px;
}

.favorites-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--overlay);
  z-index: 1000;
  display: none;
  overflow-y: auto;
  padding: 2rem 1rem;
}

.favorites-overlay.active {
  display: block;
  animation: fadeIn 0.2s ease-out;
}

body.fav-open {
  overflow: hidden;
}

.favorites-panel {
  max-width: 860px;
  margin: 0 auto;
  background: var(--paper);
  border-radius: 12px;
  min-height: 60vh;
}

.favorites-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 1.2rem;
  border-bottom: 1px solid var(--border);
}

.favorites-header h2 {
  font-family: var(--font-hanzi);
  font-size: 1.4rem;
  font-weight: 700;
  margin: 0;
}

.fav-close {
  background: none;
  border: none;
  font-size: 1.2rem;
  cursor: pointer;
  color: var(--muted);
  padding: 0.3rem;
}

.fav-close:hover {
  color: var(--ink);
}

.favorites-content {
  padding: 1rem;
}

/* App cards */
.app-intro {
  max-width: 860px;
  margin: 0 auto 1.5rem;
  background: var(--intro-gradient);
  border-left: 3px solid var(--red);
  padding: 0.9rem 1rem;
  font-size: 0.82rem;
  line-height: 1.5;
  color: var(--ink);
  border-radius: 0 8px 8px 0;
}

.app-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.9rem;
}

.app-card {
  display: flex;
  gap: 0.9rem;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1rem;
  transition: box-shadow 0.2s, transform 0.15s;
}

.app-card:hover {
  box-shadow: 0 4px 12px var(--shadow);
  transform: translateY(-1px);
}

.app-icon {
  font-size: 2.2rem;
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--paper);
  border-radius: 10px;
}

.app-content {
  flex: 1;
  min-width: 0;
}

.app-name-row {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.app-name {
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 1rem;
  color: var(--ink);
}

.app-hanzi {
  font-family: var(--font-hanzi);
  font-size: 0.9rem;
  color: var(--red);
  font-weight: 500;
}

.app-pinyin {
  font-size: 0.75rem;
  color: var(--muted);
  margin-top: 0.15rem;
}

.app-desc {
  font-size: 0.8rem;
  line-height: 1.45;
  color: var(--ink);
  margin-top: 0.4rem;
  opacity: 0.85;
}

/* ── Collapsible groups ───────────────────────────────────── */
.subsection-title { cursor: pointer; user-select: none; display: flex; align-items: center; justify-content: space-between; }
.section-title    { cursor: pointer; user-select: none; display: flex; align-items: center; justify-content: space-between; }
.collapse-chevron { width: 16px; height: 16px; flex-shrink: 0; transition: transform 0.2s ease; }
.is-collapsed .collapse-chevron { transform: rotate(-90deg); }
.subsection.is-collapsed > .section { display: none; }
.section.is-collapsed > .grid,
.section.is-collapsed > .phrase-grid { display: none; }
.search-active .subsection.is-collapsed > .section,
.search-active .section.is-collapsed > .grid,
.search-active .section.is-collapsed > .phrase-grid { display: block; }

/* ── Dark mode ────────────────────────────────────────────── */
[data-theme="dark"] {
  --ink: #f4ece0;           /* warm white, high contrast */
  --paper: #141210;         /* clean dark warm, less muddy */
  --red: #f07060;           /* brighter — section titles legible */
  --gold: #e0b828;          /* brighter gold */
  --muted: #b8a890;         /* was #9a8e7e — critical readability fix */
  --border: #2e2820;        /* subtle but visible */
  --card-bg: #201c14;       /* clearly distinct from paper */
  --shadow: rgba(0,0,0,0.4);
  --overlay: rgba(0,0,0,0.88);
  --speaking-bg: #2c2416;
  --hint-bg: #261e10;
  --gradient-red: rgba(240,112,96,0.07);
  --gradient-gold: rgba(224,184,40,0.05);
  --intro-gradient: linear-gradient(135deg, rgba(240,112,96,0.1) 0%, rgba(224,184,40,0.08) 100%);
  --lang-shadow: rgba(0,0,0,0.35);
  --focus-ring: rgba(240,112,96,0.3);
}

/* ── Quiz mode ────────────────────────────────────────────── */
[data-quiz="on"] .card:not(.revealed) .pinyin,
[data-quiz="on"] .card:not(.revealed) .meaning,
[data-quiz="on"] .phrase-card:not(.revealed) .phrase-pinyin,
[data-quiz="on"] .phrase-card:not(.revealed) .phrase-meaning { visibility: hidden; }

.quiz-btn {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 50%;
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: 1.1rem;
  font-weight: 600;
  line-height: 1;
  color: var(--muted);
  transition: color 0.2s, border-color 0.2s, background 0.2s;
  -webkit-tap-highlight-color: transparent;
}
.quiz-btn:hover { color: var(--ink); }
.quiz-btn.active {
  color: var(--gold);
  border-color: var(--gold);
  background: rgba(184,150,12,0.1);
}
[data-theme="dark"] .quiz-btn.active { background: rgba(224,184,40,0.12); }

/* ── Hide pinyin mode ─────────────────────────────────────── */
[data-pinyin="hidden"] .pinyin,
[data-pinyin="hidden"] .phrase-pinyin,
[data-pinyin="hidden"] .app-pinyin { display: none; }

.pinyin-btn {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 50%;
  cursor: pointer;
  font-family: var(--font-hanzi);
  font-size: 1rem;
  color: var(--muted);
  transition: color 0.2s, border-color 0.2s, background 0.2s;
  -webkit-tap-highlight-color: transparent;
}
.pinyin-btn:hover:not(:disabled) { color: var(--ink); }
.pinyin-btn:disabled { opacity: 0.3; cursor: not-allowed; }
.pinyin-btn.active {
  color: var(--red);
  border-color: var(--red);
  background: var(--focus-ring);
}

/* ── Global search: show all panels stacked ──────────────── */
#panels.global-search .tab-panel          { display: block; }
#panels.global-search .tab-panel.no-match { display: none; }

/* ── Per-panel tab label (visible in global search only) ─── */
.panel-search-label {
  display: none;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  padding: 1.8rem 0 0.5rem;
  margin-bottom: 0.4rem;
  border-top: 1px solid var(--border);
}
#panels.global-search .tab-panel:first-child .panel-search-label {
  padding-top: 0;
  border-top: none;
}
#panels.global-search .panel-search-label { display: block; }

/* Theme toggle button */
.theme-btn {
  position: fixed;
  top: calc(env(safe-area-inset-top) + 0.75rem);
  left: calc(env(safe-area-inset-left) + 0.75rem);
  z-index: 100;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 999px;
  width: 2.25rem;
  height: 2.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 2px 8px var(--lang-shadow);
  color: var(--ink);
  transition: background 0.2s, border-color 0.2s, color 0.2s;
  -webkit-tap-highlight-color: transparent;
  font-size: 1rem;
  line-height: 1;
}