.mobile-keyboard-wrap {
  --mk-key: #2b2d33;
  --mk-key-active: #50545d;
  --mk-key-special: #23252b;
  --mk-text: #f2f2f2;
  --mk-line: rgba(255, 255, 255, 0.08);
  --mk-safe-bottom: env(safe-area-inset-bottom, 0px);
  --mk-z: 50;

  --mk-max: min(96vw, 900px);
  --mk-gap: clamp(4px, 1.2vw, 10px);
  --mk-radius: clamp(10px, 1.8vw, 16px);
  --mk-key-h: clamp(42px, 7vw, 60px);

  --mk-font-key: clamp(14px, 2.6vw, 18px);
  --mk-font-key-small: clamp(12px, 2.2vw, 15px);
  --mk-font-key-tiny: clamp(11px, 2vw, 13px);

  --mk-candidate-h: clamp(34px, 5.6vw, 40px);
  --mk-candidate-font: clamp(16px, 3vw, 20px);
  --mk-candidate-key-font: clamp(9px, 1.8vw, 11px);
  --mk-candidate-page-font: clamp(10px, 1.9vw, 12px);

  --mk-compose-h: clamp(34px, 5.6vw, 40px);
  --mk-compose-font: clamp(15px, 2.7vw, 18px);

  --mk-nav-size: clamp(34px, 5.6vw, 40px);

  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: var(--mk-z);
  background: linear-gradient(to top, rgba(17, 18, 20, 1), rgba(17, 18, 20, 0.98));
  border-top: 1px solid var(--mk-line);
  padding:
    clamp(8px, 1.5vw, 12px)
    clamp(8px, 1.5vw, 12px)
    calc(clamp(8px, 1.5vw, 12px) + var(--mk-safe-bottom));
  box-shadow: 0 -10px 30px rgba(0, 0, 0, 0.35);
  color: var(--mk-text);
  font-family: "Noto Sans TC", "Microsoft JhengHei", Arial, sans-serif;
  box-sizing: border-box;
}

.mobile-keyboard-wrap,
.mobile-keyboard-wrap *,
.mobile-keyboard-wrap *::before,
.mobile-keyboard-wrap *::after {
  box-sizing: border-box;
}

.mobile-keyboard {
  width: var(--mk-max);
  margin: 0 auto;
  user-select: none;
  -webkit-user-select: none;
  touch-action: none;
}

.mobile-keyboard .kb-row {
  display: flex;
  gap: var(--mk-gap);
  margin-bottom: var(--mk-gap);
}

.mobile-keyboard .kb-row:last-child {
  margin-bottom: 0;
}

.mobile-keyboard button {
  font: inherit;
}

.mobile-keyboard .mk-key {
  appearance: none;
  -webkit-appearance: none;
  border: 0;
  min-width: 0;
  min-height: var(--mk-key-h);
  height: var(--mk-key-h);
  border-radius: var(--mk-radius);
  background: var(--mk-key);
  color: var(--mk-text);
  font-size: var(--mk-font-key);
  line-height: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  position: relative;
  flex: 1 1 0;
  cursor: pointer;
  transition: transform 0.04s ease, background 0.08s ease;
  box-shadow: inset 0 -1px 0 rgba(255, 255, 255, 0.05);
  -webkit-tap-highlight-color: transparent;
}

.mobile-keyboard .mk-key--special {
  background: var(--mk-key-special);
  font-size: clamp(13px, 2.4vw, 17px);
}

.mobile-keyboard .mk-key.is-active,
.mobile-keyboard .mk-key.is-pressed {
  background: var(--mk-key-active);
  transform: translateY(1px) scale(0.985);
}

.mobile-keyboard .mk-key.is-lock {
  box-shadow:
    inset 0 -1px 0 rgba(255, 255, 255, 0.05),
    0 0 0 2px rgba(110, 168, 255, 0.35);
}

.mobile-keyboard .mk-key:focus-visible,
.mobile-keyboard .mk-candidate:focus-visible,
.mobile-keyboard .mk-candidate-nav:focus-visible {
  outline: 2px solid rgba(110, 168, 255, 0.85);
  outline-offset: 2px;
}

.mobile-keyboard .mk-key.wide-125 { flex: 1.25 1.25 0; }
.mobile-keyboard .mk-key.wide-150 { flex: 1.5 1.5 0; }
.mobile-keyboard .mk-key.wide-175 { flex: 1.75 1.75 0; }
.mobile-keyboard .mk-key.wide-200 { flex: 2 2 0; }
.mobile-keyboard .mk-key.wide-250 { flex: 2.5 2.5 0; }
.mobile-keyboard .mk-key.wide-300 { flex: 3 3 0; }
.mobile-keyboard .mk-key.wide-400 { flex: 4 4 0; }

.mobile-keyboard .mk-key__sub {
  position: absolute;
  top: 4px;
  right: 6px;
  font-size: clamp(8px, 1.5vw, 10px);
  color: rgba(255, 255, 255, 0.45);
  pointer-events: none;
}

.mobile-keyboard .mk-key__main {
  display: inline-block;
  text-align: center;
  pointer-events: none;
  white-space: nowrap;
  max-width: 100%;
  padding: 0 2px;
}

.mobile-keyboard .mk-key--small .mk-key__main {
  font-size: var(--mk-font-key-small);
}

.mobile-keyboard .mk-key--tiny .mk-key__main {
  font-size: var(--mk-font-key-tiny);
}

/* ========================= 候選字區 ========================= */

.mobile-keyboard .mk-candidate-bar {
  display: flex;
  align-items: center;
  gap: var(--mk-gap);
  margin-bottom: var(--mk-gap);
  padding: clamp(4px, 1vw, 8px) clamp(6px, 1.2vw, 10px);
  border: 1px solid var(--mk-line);
  border-radius: clamp(10px, 1.8vw, 12px);
  background: rgba(255, 255, 255, 0.04);
  overflow: hidden;
}

.mobile-keyboard .mk-candidate-bar[hidden] {
  display: none;
}

.mobile-keyboard .mk-candidate-scroller {
  display: flex;
  align-items: center;
  gap: clamp(4px, 1vw, 6px);
  flex: 1 1 auto;
  min-width: 0;
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

.mobile-keyboard .mk-candidate-scroller::-webkit-scrollbar {
  display: none;
}

.mobile-keyboard .mk-candidate {
  appearance: none;
  -webkit-appearance: none;
  border: 0;
  flex: 0 0 auto;
  min-width: 0;
  height: var(--mk-candidate-h);
  padding: 0 clamp(8px, 1.8vw, 10px);
  border-radius: clamp(8px, 1.6vw, 10px);
  background: var(--mk-key);
  color: var(--mk-text);
  display: inline-flex;
  align-items: center;
  gap: clamp(4px, 1vw, 6px);
  cursor: pointer;
  box-shadow: inset 0 -1px 0 rgba(255, 255, 255, 0.05);
  transition: transform 0.04s ease, background 0.08s ease;
  -webkit-tap-highlight-color: transparent;
}

.mobile-keyboard .mk-candidate.is-active,
.mobile-keyboard .mk-candidate:active {
  background: var(--mk-key-active);
  transform: translateY(1px) scale(0.985);
}

.mobile-keyboard .mk-candidate__key {
  flex: 0 0 auto;
  font-size: var(--mk-candidate-key-font);
  color: rgba(255, 255, 255, 0.5);
  line-height: 1;
}

.mobile-keyboard .mk-candidate__text {
  flex: 0 0 auto;
  font-size: var(--mk-candidate-font);
  line-height: 1;
  white-space: nowrap;
}

.mobile-keyboard .mk-candidate-page {
  flex: 0 0 auto;
  font-size: var(--mk-candidate-page-font);
  color: rgba(255, 255, 255, 0.68);
  white-space: nowrap;
  padding-left: 4px;
}

.mobile-keyboard .mk-candidate-nav {
  appearance: none;
  -webkit-appearance: none;
  flex: 0 0 auto;
  width: var(--mk-nav-size);
  height: var(--mk-nav-size);
  border: 0;
  border-radius: clamp(8px, 1.6vw, 10px);
  background: var(--mk-key-special);
  color: var(--mk-text);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: clamp(13px, 2.3vw, 16px);
  cursor: pointer;
  box-shadow: inset 0 -1px 0 rgba(255, 255, 255, 0.05);
  transition: transform 0.04s ease, background 0.08s ease;
  -webkit-tap-highlight-color: transparent;
}

.mobile-keyboard .mk-candidate-nav.is-pressed,
.mobile-keyboard .mk-candidate-nav:active {
  background: var(--mk-key-active);
  transform: translateY(1px) scale(0.985);
}

.mobile-keyboard .mk-candidate-nav[hidden] {
  display: none;
}

.mobile-keyboard .mk-candidate-placeholder {
  flex: 1 1 auto;
  min-width: 0;
  height: 1px;
}

/* ========================= 組字預覽 ========================= */

.mobile-keyboard .mk-compose {
  flex: 0 0 auto;
  min-width: clamp(44px, 10vw, 56px);
  max-width: clamp(90px, 24vw, 140px);
  height: var(--mk-compose-h);
  padding: 0 clamp(8px, 1.8vw, 10px);
  border-radius: clamp(8px, 1.6vw, 10px);
  background: rgba(255, 255, 255, 0.06);
  color: var(--mk-text);
  display: inline-flex;
  align-items: center;
  justify-content: flex-start;
  gap: 2px;
  overflow: hidden;
  white-space: nowrap;
  box-shadow: inset 0 -1px 0 rgba(255, 255, 255, 0.05);
}

.mobile-keyboard .mk-compose[hidden] {
  display: none;
}

.mobile-keyboard .mk-compose__text {
  font-size: var(--mk-compose-font);
  line-height: 1;
  white-space: nowrap;
}

.mobile-keyboard .mk-compose__cursor {
  font-size: var(--mk-compose-font);
  line-height: 1;
  opacity: 0.9;
  animation: mkCursorBlink 1s steps(1) infinite;
}

@keyframes mkCursorBlink {
  50% {
    opacity: 0.2;
  }
}

/* ========================= 額外 breakpoint ========================= */

@media (max-width: 380px) {
  .mobile-keyboard-wrap {
    --mk-max: 100%;
    --mk-gap: 4px;
    --mk-radius: 10px;
    --mk-key-h: 40px;
    --mk-font-key: 13px;
    --mk-font-key-small: 11px;
    --mk-font-key-tiny: 10px;
    --mk-candidate-font: 15px;
    --mk-compose-font: 14px;
    padding-left: 6px;
    padding-right: 6px;
  }

  .mobile-keyboard .mk-key__main {
    padding: 0 2px;
  }
}

/* Short viewports (mobile browser chrome + form): keep all key rows visible */
@media (max-height: 750px) {
  .mobile-keyboard-wrap {
    --mk-key-h: clamp(34px, 5.2vh, 42px);
    --mk-gap: 4px;
    --mk-candidate-h: clamp(30px, 4.5vh, 36px);
    --mk-compose-h: clamp(30px, 4.5vh, 36px);
    --mk-nav-size: clamp(30px, 4.5vh, 36px);
    padding-top: 6px;
    padding-bottom: calc(6px + var(--mk-safe-bottom));
  }
}

@media (max-height: 640px) {
  .mobile-keyboard-wrap {
    --mk-key-h: clamp(30px, 4.6vh, 38px);
    --mk-gap: 3px;
    --mk-font-key: clamp(12px, 2.2vw, 15px);
    --mk-font-key-small: clamp(10px, 1.8vw, 12px);
  }
}

@media (min-width: 381px) and (max-width: 767px) {
  .mobile-keyboard-wrap {
    --mk-max: 100%;
  }
}

@media (min-width: 768px) and (max-width: 1024px) {
  .mobile-keyboard-wrap {
    --mk-max: min(94vw, 820px);
    --mk-key-h: clamp(48px, 5.2vw, 58px);
    --mk-font-key: clamp(15px, 2vw, 18px);
  }
}

@media (min-width: 1025px) {
  .mobile-keyboard-wrap {
    --mk-max: min(88vw, 900px);
    --mk-key-h: 60px;
    --mk-gap: 10px;
  }
}

.mobile-keyboard-wrap.is-hidden {
  display: none !important;
}

.function {
  position: fixed;
  top: 0;
  left: 0;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
  overflow: hidden;
}