:root {
  --bg: #f4f5f8;
  --surface: #ffffff;
  --text: #16213a;
  --muted: #6b7489;
  --line: #e2e5ec;
  --accent: #2f5bea;
  --accent-soft: #e6ecff;
  --on-accent: #ffffff;
  --warn: #b5650d;
  --key: #ffffff;
  --key-fn: #e7e9f0;
  --key-op: #dfe6ff;
  --radius: 14px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1525;
    --surface: #182036;
    --text: #eef1f8;
    --muted: #98a2bb;
    --line: #273152;
    --accent: #7d9bff;
    --accent-soft: #24305a;
    --on-accent: #0f1525;
    --warn: #f0a24a;
    --key: #1d2640;
    --key-fn: #263052;
    --key-op: #2b3a6e;
  }
}

* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; overscroll-behavior: none; }  /* no swipe-to-go-back from the panes */
body {
  background: var(--bg);
  color: var(--text);
  font: 16px/1.4 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  overflow: hidden;
  -webkit-tap-highlight-color: transparent;
}
button { font: inherit; color: inherit; cursor: pointer; }

/* Same phone layout everywhere; on wide screens it is just centered. */
.app {
  height: 100dvh;
  max-width: 480px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  background: var(--bg);
}

/* --- Tabs ------------------------------------------------------------------- */
.tabs {
  position: relative;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  padding-top: env(safe-area-inset-top);
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}
.tabs button {
  border: 0;
  background: none;
  padding: 12px 4px;
  color: var(--muted);
  font-weight: 600;
}
.tabs button[aria-selected="true"] { color: var(--accent); }
.tab-indicator {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 33.333%;
  height: 3px;
  background: var(--accent);
  border-radius: 3px;
  transition: transform .15s ease-out;
}

/* --- Panes: horizontal swipe with scroll snap --------------------------------- */
.panes {
  flex: 1;
  display: flex;
  overflow-x: auto;
  overflow-y: hidden;
  scroll-snap-type: x mandatory;
  scrollbar-width: none;
  overscroll-behavior-x: contain;
}
.panes::-webkit-scrollbar { display: none; }
.pane {
  flex: 0 0 100%;
  scroll-snap-align: start;
  scroll-snap-stop: always;
  overflow-y: auto;
  padding: 0 16px calc(16px + env(safe-area-inset-bottom));
}

.pane-head {
  position: sticky;
  top: 0;
  z-index: 1;
  background: var(--bg);
  padding: 14px 0 8px;
}
.pane-number { font-size: 1.6rem; font-weight: 700; }
.pane-sub { color: var(--muted); font-size: .9rem; }

.chips {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding: 10px 0 2px;
  scrollbar-width: none;
}
.chips::-webkit-scrollbar { display: none; }
.chips button {
  flex: 0 0 auto;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 999px;
  padding: 5px 12px;
  font-size: .85rem;
}
.chips button[aria-pressed="true"] {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--on-accent);
}

/* --- Center: display and keypad ------------------------------------------------ */
.pane-pad {
  display: flex;
  flex-direction: column;
  overflow-y: hidden;
  padding-top: 8px;
}
.display {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  align-items: flex-end;
  text-align: right;
  min-height: 0;
  padding: 8px 4px;
  overflow: hidden;
}
/* Short explanation of the app; hidden when the display gets too low for it. */
.display { container-type: size; }
.intro {
  align-self: stretch;
  text-align: left;
  margin: 4px 0 auto;
  color: var(--muted);
  font-size: .95rem;
  line-height: 1.45;
}
.intro span { display: block; margin-top: 6px; font-size: .85rem; }
@container (max-height: 230px) { .intro { font-size: .8rem; line-height: 1.35; } .intro span { display: none; } }
@container (max-height: 140px) { .intro { display: none; } }
.intro + .clip-note:not([hidden]) { margin-top: 10px; }
.intro:has(+ .clip-note:not([hidden])) { margin-bottom: 0; }
.clip-note {
  align-self: stretch;
  text-align: left;
  font-size: .85rem;
  color: var(--accent);
  background: var(--accent-soft);
  border-radius: 10px;
  padding: 8px 10px;
  margin-bottom: auto;
}
.clip-note button {
  border: 0;
  background: none;
  color: inherit;
  text-decoration: underline;
  padding: 0 0 0 6px;
}
.expr {
  color: var(--muted);
  font-size: 1.1rem;
  min-height: 1.5em;
  word-break: break-all;
}
.result {
  max-width: 100%;
  font-size: 3.2rem;       /* app.js shrinks it so long numbers stay on one line */
  font-weight: 700;
  line-height: 1.1;
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}
.words { color: var(--accent); font-weight: 600; min-height: 1.4em; }

.hint {
  display: flex;
  justify-content: space-between;
  padding: 4px 0 10px;
}
.hint-btn {
  border: 0;
  background: none;
  color: var(--accent);
  font-size: .9rem;
  padding: 6px 2px;
}

.keypad {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}
.keypad button {
  height: clamp(52px, 8.5dvh, 68px);
  border: 0;
  border-radius: var(--radius);
  background: var(--key);
  font-size: 1.45rem;
  box-shadow: 0 1px 0 var(--line);
  touch-action: manipulation;
  user-select: none;
}
.keypad button:active { filter: brightness(.92); transform: scale(.97); }
.keypad .k-fn { background: var(--key-fn); }
.keypad .k-op { background: var(--key-op); color: var(--accent); font-weight: 600; }
.keypad .k-eq { background: var(--accent); color: var(--on-accent); font-weight: 600; }

/* --- Big Numbers list ------------------------------------------------------------- */
.bn-list, .m2m-list { list-style: none; margin: 0; padding: 0; }
.bn-list li {
  background: var(--surface);
  border-radius: var(--radius);
  margin: 6px 0;
  padding: 10px 12px;
  cursor: pointer;
}
.bn-row { display: flex; gap: 10px; align-items: baseline; }
.bn-title { flex: 1; min-width: 0; }

/* List marks: each list brings its own color (--lc / --lc-dark) and line icon. */
.lc { color: var(--lc); }
@media (prefers-color-scheme: dark) { .lc { color: var(--lc-dark); } }
.list-icon { width: 15px; height: 15px; vertical-align: -2px; margin-right: 6px; flex: none; }
.chips .list-chip { display: inline-flex; align-items: center; }
.chips .list-chip[aria-pressed="true"] { border-color: currentColor; background: var(--surface); color: var(--lc); }
@media (prefers-color-scheme: dark) { .chips .list-chip[aria-pressed="true"] { color: var(--lc-dark); } }
.chips .list-chip .list-icon { margin-right: 5px; }
.bn-list li.open { padding: 0; overflow: hidden; }
.bn-list li.open .bn-row { padding: 10px 12px 0; }
.bn-list li.open .bn-detail { padding: 0 12px 12px; }
.bn-figure { margin: 0; }
.bn-figure img { display: block; width: 100%; height: auto; max-height: 240px; object-fit: cover; }
.bn-figure figcaption { font-size: .7rem; color: var(--muted); text-align: right; padding: 4px 12px 0; }
.bn-figure figcaption a { color: inherit; }
.bn-panel {
  display: flex; align-items: center; justify-content: center; gap: 12px;
  height: 96px; font-weight: 700; font-size: 1.05rem;
  background: color-mix(in srgb, currentColor 12%, var(--surface));
}
.bn-panel-icon { width: 44px; height: 44px; stroke-width: 1.5; }
.bn-title small { color: var(--muted); margin-left: 4px; }
.bn-value { font-weight: 700; white-space: nowrap; font-variant-numeric: tabular-nums; }
.bn-ratio { color: var(--muted); font-size: .8rem; text-align: right; }
.bn-list li.mine {
  background: var(--accent);
  color: var(--on-accent);
  cursor: default;
}
.bn-detail { margin-top: 8px; font-size: .9rem; color: var(--muted); }
.bn-detail p { margin: 6px 0; }
.bn-detail a { color: var(--accent); }
.badge {
  display: inline-block;
  font-size: .7rem;
  font-weight: 600;
  border-radius: 6px;
  padding: 1px 6px;
  margin-right: 4px;
  background: var(--key-fn);
  color: var(--muted);
}
.badge.warn { color: var(--warn); }
.more {
  width: 100%;
  border: 1px dashed var(--line);
  background: none;
  color: var(--accent);
  border-radius: var(--radius);
  padding: 10px;
  margin: 6px 0;
}
.more[hidden] { display: none; }
.legal { margin: 18px 0 8px; text-align: center; font-size: 13px; color: var(--muted); }
.legal a { color: inherit; }

/* --- Mean2Me ---------------------------------------------------------------------------- */
.m2m-list li {
  background: var(--surface);
  border-radius: var(--radius);
  margin: 8px 0;
  padding: 12px 14px;
}
.m2m-value { font-size: 1.5rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.m2m-label { font-weight: 600; }
.m2m-source { color: var(--muted); font-size: .8rem; margin-top: 4px; }

.empty { color: var(--muted); text-align: center; padding: 40px 10px; }

/* --- List sheet ------------------------------------------------------------------------- */
.sheet {
  width: min(480px, 100%);
  max-width: 100%;
  max-height: 85dvh;
  margin: auto auto 0;
  padding: 0 16px calc(16px + env(safe-area-inset-bottom));
  border: 0;
  border-radius: 18px 18px 0 0;
  background: var(--bg);
  color: var(--text);
}
.sheet::backdrop { background: rgb(0 0 0 / .4); }
.sheet-head {
  position: sticky;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0 6px;
  background: var(--bg);
}
.sheet-head h2 { margin: 0; font-size: 1.2rem; }
.sheet-head button { border: 0; background: none; font-size: 1.2rem; padding: 6px; }
.sheet-intro { color: var(--muted); font-size: .9rem; margin: 0 0 8px; }
.sheet-lists { list-style: none; margin: 0; padding: 0; }
.sheet-lists li { background: var(--surface); border-radius: var(--radius); margin: 8px 0; }
.sheet-lists label { display: flex; gap: 12px; align-items: center; padding: 12px 14px; cursor: pointer; }
.sheet-icon { width: 24px; height: 24px; flex: none; align-self: flex-start; margin-top: 2px; }
.sheet-text { flex: 1; display: flex; flex-direction: column; gap: 2px; }
.sheet-text span { font-size: .9rem; color: var(--muted); }
.sheet-text small { font-size: .75rem; color: var(--muted); }
.sheet-lists input { width: 22px; height: 22px; accent-color: var(--accent); flex: none; }

/* --- Mean2Me: country, own divisors -------------------------------------------------------- */
.m2m-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.country-btn, .country-choice {
  display: inline-flex; align-items: center; gap: 8px;
  border: 1px solid var(--line); background: var(--surface);
  border-radius: 999px; padding: 6px 12px; font-size: .95rem; min-height: 44px;
}
.flag { font-size: 1.4rem; line-height: 1; }
.country-choice { width: 100%; border-radius: var(--radius); padding: 12px 14px; text-align: left; }
.country-choice[aria-pressed="true"] { border-color: var(--accent); box-shadow: inset 0 0 0 1px var(--accent); }
.sheet-lists li:has(.country-choice) { background: none; }
.m2m-label { display: flex; justify-content: space-between; gap: 8px; align-items: flex-start; }
.m2m-remove { border: 0; background: none; color: var(--muted); padding: 0 4px; font-size: 1rem; }
.custom-form { display: flex; flex-direction: column; gap: 12px; padding-bottom: 8px; }
.custom-form label { display: flex; flex-direction: column; gap: 4px; font-weight: 600; font-size: .9rem; }
.custom-form input {
  font: inherit; font-weight: 400; padding: 10px 12px; border-radius: 10px;
  border: 1px solid var(--line); background: var(--surface); color: var(--text);
}
.m2m-list li.m2m-mine { background: var(--accent-soft); box-shadow: inset 0 0 0 1.5px var(--accent); }
.m2m-mine .m2m-value { color: var(--accent); }
.m2m-edit { border: 0; background: none; color: var(--accent); font: inherit; font-size: .85rem; font-weight: 600; padding: 0 2px; min-height: 32px; }
.m2m-list li.m2m-invite { padding: 0; background: none; }
.m2m-invite button {
  width: 100%; text-align: left; display: flex; flex-direction: column; gap: 2px; padding: 12px 14px;
  border: 1.5px dashed var(--accent); border-radius: var(--radius); background: var(--accent-soft); color: var(--text); font: inherit;
}
.m2m-invite strong { color: var(--accent); }
.m2m-invite span { color: var(--muted); font-size: .85rem; }
.tax-remove { border: 0; background: none; color: var(--muted); font: inherit; min-height: 44px; }
.tax-remove[hidden] { display: none; }
.custom-form button[type="submit"] {
  border: 0; border-radius: var(--radius); padding: 12px; font-weight: 600;
  background: var(--accent); color: var(--on-accent); min-height: 44px;
}

/* --- Toast -------------------------------------------------------------------------------- */
.toast {
  position: fixed;
  left: 50%;
  bottom: calc(24px + env(safe-area-inset-bottom));
  transform: translateX(-50%);
  max-width: calc(100% - 32px);
  background: var(--text);
  color: var(--bg);
  padding: 10px 16px;
  border-radius: 12px;
  font-size: .9rem;
  z-index: 10;
}