.full-reading-app.is-reading-overview-page .poster-tile.is-challenge {
  border-color: transparent;
  background: #f6e7c1;
}

.full-reading-app.is-reading-overview-page .poster-tile.is-challenge .poster-tile-actions button {
  background: rgba(255, 251, 235, 0.72);
}

.speaking-modal-dialog.is-sentence-challenge .speaking-modal-heading,
.speaking-modal-dialog.is-sentence-challenge .speaking-guided-reading-toggle,
.speaking-modal-dialog.is-sentence-challenge .speaking-mode-picker,
.speaking-modal-dialog.is-sentence-challenge .speaking-panel-head,
.speaking-modal-dialog.is-sentence-challenge .reading-tools,
.speaking-modal-dialog.is-sentence-challenge #speakingInput,
.speaking-modal-dialog.is-sentence-challenge > .reading-feedback,
.speaking-modal-dialog.is-sentence-challenge .speaking-voice-reception,
.speaking-modal-dialog.is-sentence-challenge .word-radar-preheat,
.speaking-modal-dialog.is-sentence-challenge .speaking-immersive-word-scores,
.speaking-modal-dialog.is-sentence-challenge .speaking-translation-hint,
.speaking-modal-dialog.is-sentence-challenge .appreciate-hints {
  display: none !important;
}

.speaking-modal-dialog.is-immersive-reading-mode.is-sentence-challenge .speaking-stage-board {
  padding-bottom: 230px;
}

.speaking-modal-dialog.is-immersive-reading-mode.is-sentence-challenge .speaking-immersive-translation {
  font-size: 22px;
  font-weight: 560;
  letter-spacing: 0.01em;
  color: #fff;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.72);
  cursor: pointer;
  pointer-events: auto;
}

.speaking-modal-dialog.is-sentence-challenge .sc-blank {
  display: inline-block;
  min-width: 1.8em;
  margin: 0 0.16em;
  border-bottom: 3px solid rgba(255, 251, 235, 0.95);
  color: transparent;
  transform: translateY(-0.08em);
  filter: drop-shadow(0 1px 1px rgba(2, 6, 23, 0.65));
}

.speaking-modal-dialog.is-sentence-challenge .sc-filled {
  display: inline-block;
  padding: 0 0.12em;
  border-radius: 0.2em;
  background: rgba(254, 240, 138, 0.72);
  animation: sentence-challenge-fill 520ms ease;
}

@keyframes sentence-challenge-fill {
  from { background: rgba(254, 240, 138, 0); }
  40% { background: rgba(254, 240, 138, 0.95); }
  to { background: rgba(254, 240, 138, 0.72); }
}

.sentence-challenge {
  position: fixed;
  z-index: 16;
  left: 50%;
  bottom: max(16px, env(safe-area-inset-bottom));
  width: min(1080px, calc(100vw - 120px));
  transform: translateX(-50%);
  pointer-events: auto;
}

.sentence-challenge[hidden] {
  display: none !important;
}

.sentence-challenge-options {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}

.sentence-challenge-option {
  position: relative;
  min-width: 0;
  overflow-wrap: anywhere;
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  border: 2px solid rgba(255, 255, 255, 0.42);
  border-radius: 16px;
  background: rgba(255, 251, 235, 0.9);
  color: #1c1917;
  padding: 10px 14px;
  font: inherit;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 28px;
  line-height: 1.15;
  text-align: center;
  box-shadow: 0 10px 24px rgba(28, 25, 23, 0.12);
}

.sentence-challenge-option span {
  flex: none;
  color: rgba(28, 25, 23, 0.48);
  font-family: inherit;
  font-size: 18px;
  font-weight: 750;
}

.sentence-challenge-option:hover:not(:disabled) {
  background: #fff;
}

.sentence-challenge-option.is-armed:not(:disabled) {
  background: #fff;
  border-color: #1c1917;
  box-shadow: 0 0 0 3px rgba(255, 251, 235, 0.9), 0 12px 28px rgba(28, 25, 23, 0.22);
  transform: translateY(-2px);
}

.sentence-challenge-option.is-correct {
  background: #bbf7d0;
  border-color: #15803d;
  color: #14532d;
}

.sentence-challenge-option.is-wrong {
  background: #e11d48;
  border-color: #9f1239;
  color: #fff;
}

.sentence-challenge-option.is-wrong span {
  color: rgba(255, 255, 255, 0.86);
}

.sentence-challenge-option.is-correct.is-feedback {
  animation: sentence-challenge-pop 460ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.sentence-challenge-option.is-wrong.is-feedback {
  animation: sentence-challenge-shake 460ms ease;
}

.sentence-challenge-lottie {
  position: absolute;
  left: 50%;
  top: 0;
  width: 84px;
  height: 84px;
  transform: translate(-50%, -78%);
  pointer-events: none;
  z-index: 2;
}

@keyframes sentence-challenge-pop {
  0% { transform: scale(1); }
  38% { transform: scale(1.1); }
  100% { transform: scale(1); }
}

@keyframes sentence-challenge-shake {
  0%, 100% { transform: translateX(0); }
  18% { transform: translateX(-9px); }
  36% { transform: translateX(9px); }
  54% { transform: translateX(-6px); }
  72% { transform: translateX(4px); }
}

.sentence-challenge-misses {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  max-width: min(280px, 46vw);
  pointer-events: none;
}

.sentence-challenge-misses[hidden] {
  display: none !important;
}

.sentence-challenge-miss {
  width: 10px;
  height: 10px;
  flex: none;
  border-radius: 2px;
  background: #e11d48;
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.78), 0 1px 4px rgba(2, 6, 23, 0.4);
  transition: transform 220ms ease, opacity 220ms ease;
}

.sentence-challenge-miss.is-gone {
  transform: scale(0);
  opacity: 0;
}

.sentence-challenge-option:disabled {
  cursor: default;
}

.sentence-challenge-note,
.sentence-challenge-toolbar {
  margin: 8px 0 0;
  color: rgba(255, 255, 255, 0.92);
  font-size: 14px;
  line-height: 1.4;
  text-align: center;
  text-shadow: 0 1px 8px rgba(2, 6, 23, 0.72);
}

.sentence-challenge-note[hidden] {
  display: none !important;
}

.sentence-challenge-toolbar {
  display: flex;
  justify-content: center;
  gap: 8px;
}

.sentence-challenge-toolbar button,
.sentence-challenge-summary button {
  border: 0;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.38);
  color: #fff;
  padding: 6px 12px;
  font: inherit;
  font-size: 13px;
}

.sentence-challenge-summary {
  padding: 16px 16px 12px;
  border-radius: 18px;
  background: rgba(28, 25, 23, 0.62);
  color: #fff;
  backdrop-filter: blur(10px);
}

.sentence-challenge-summary[hidden] {
  display: none !important;
}

.sentence-challenge-kicker,
.sentence-challenge-lead,
.sentence-challenge-coach {
  margin: 0;
  text-align: center;
}

.sentence-challenge-kicker {
  font-size: 13px;
  letter-spacing: 0.08em;
  opacity: 0.78;
}

.sentence-challenge-score {
  margin: 4px 0 8px;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 32px;
  text-align: center;
}

.sentence-challenge-lead,
.sentence-challenge-clusters p,
.sentence-challenge-coach {
  font-size: 14px;
  line-height: 1.45;
}

.sentence-challenge-clusters {
  display: grid;
  gap: 8px;
  margin: 12px 0;
}

.sentence-challenge-clusters section {
  padding: 8px 10px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.08);
}

.sentence-challenge-clusters header {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  font-size: 13px;
  letter-spacing: 0.04em;
}

.sentence-challenge-clusters p {
  margin: 4px 0 8px;
}

.sentence-challenge-clusters button,
.sentence-challenge-summary > button {
  margin-top: 4px;
}

@media (max-width: 720px) {
  .speaking-modal-dialog.is-immersive-reading-mode.is-sentence-challenge .speaking-immersive-bgm {
    bottom: calc(max(10px, env(safe-area-inset-bottom)) + 200px);
  }

  .speaking-modal-dialog.is-immersive-reading-mode.is-sentence-challenge .speaking-immersive-translation {
    font-size: 20px;
  }

  .sentence-challenge {
    width: min(100vw - 24px, 720px);
  }

  .sentence-challenge-option {
    min-height: 56px;
    gap: 6px;
    padding: 8px 8px;
    font-size: 20px;
  }

  .sentence-challenge-option span {
    font-size: 14px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .sentence-challenge-option.is-feedback {
    animation: none;
  }

  .sentence-challenge-lottie,
  .sentence-challenge-miss {
    transition: none;
  }
}