@import url("https://fonts.googleapis.com/css2?family=Noto+Serif+SC:wght@400;700;900&family=ZCOOL+KuaiLe&display=swap");
/* Fallback: if Google Fonts unavailable (offline/firewall), system CJK fonts cover all characters */
:root {
  --bg: #faf5ec;
  --text: #1a1008;
  --text2: #6b4f2a;
  --accent: #c13b0a;
  --accent2: #e07b20;
  --green: #2a7a52;
  --green-lt: #e8f5ee;
  --red: #b52020;
  --red-lt: #ffebee;
  --gold: #c8941a;
  --card: #ffffff;
  --paper-alt: #f2ead8;
  --radius: 14px;
  --fs-base: 16px;
  --fs-char: clamp(1.9rem, 7.5vw, 2.8rem);
  --fs-opt: clamp(1.3rem, 5.5vw, 1.8rem);
  --shadow-sm: 0 2px 8px rgba(26, 16, 8, 0.08);
  --shadow-md: 0 4px 20px rgba(26, 16, 8, 0.12);
}
.big-font {
  --fs-base: 20px;
  --fs-char: clamp(2.2rem, 9vw, 3.4rem);
  --fs-opt: clamp(1.6rem, 7vw, 2.2rem);
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}
body {
  font-family:
    "Noto Serif SC", "PingFang SC", "Songti SC", "SimSun",
    "Source Han Serif CN", serif;
  background: var(--bg);
  color: var(--text);
  font-size: var(--fs-base);
  min-height: 100dvh;
  overflow-x: hidden;
}
.header {
  background: #c13b0a;
  color: #fff;
  padding: 10px 14px;
  display: flex;
  align-items: center;
  gap: 8px;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 14px rgba(193, 59, 10, 0.4);
}
.header-title {
  font-family: "ZCOOL KuaiLe", cursive;
  font-size: clamp(1rem, 4vw, 1.3rem);
  letter-spacing: 2px;
  flex: 1;
  text-align: center;
}
.header-right {
  display: flex;
  gap: 6px;
  align-items: center;
  flex-shrink: 0;
}
.icon-btn {
  background: rgba(255, 255, 255, 0.18);
  border: none;
  color: #fff;
  min-width: 44px;
  min-height: 44px;
  border-radius: 50%;
  font-size: 1.05rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
  flex-shrink: 0;
}
.icon-btn:active {
  background: rgba(255, 255, 255, 0.38);
}
.icon-btn.active {
  background: rgba(255, 255, 255, 0.45);
}
.back-btn {
  font-size: 1.3rem;
  text-decoration: none;
}
.info-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  background: var(--card);
  border-bottom: 1px solid #e8d8c0;
  padding: 7px 20px;
}
.info-item {
  font-family: "ZCOOL KuaiLe", cursive;
  font-size: 1rem;
  color: var(--text2);
}
.info-item span {
  color: var(--accent);
  font-size: 1.1rem;
}
.info-divider {
  width: 1px;
  height: 16px;
  background: #e0d0b8;
  margin: 0 16px;
}
.info-wb {
  cursor: pointer;
  color: var(--accent2);
  transition: opacity 0.15s;
}
.info-wb:active {
  opacity: 0.6;
}
.wb-badge {
  background: #fff;
  color: var(--red);
  border: 1.5px solid var(--red);
  border-radius: 10px;
  padding: 1px 6px;
  font-size: 0.8rem;
  font-weight: 900;
  font-family: "Noto Serif SC", serif;
  margin-left: 4px;
  vertical-align: middle;
  display: inline-block;
  text-align: center;
}
.wb-badge.empty {
  background: transparent;
  border-color: #c8b89a;
  color: #c8b89a;
}
.wb-body {
  max-height: 52vh;
  overflow-y: auto;
  padding: 10px 16px;
}
.wb-item {
  padding: 12px 0;
  border-bottom: 1px solid #f0e4d0;
}
.wb-item:last-child {
  border-bottom: none;
}
.wb-word {
  font-size: 1.4rem;
  font-weight: 900;
  letter-spacing: 3px;
  color: var(--text);
}
.wb-pinyin {
  font-size: 0.78rem;
  color: var(--text2);
  margin: 2px 0 6px;
}
.wb-explain {
  font-size: 0.85rem;
  color: #5d4e37;
  line-height: 1.6;
  background: #fff8f0;
  border-radius: 6px;
  padding: 8px 10px;
  border-left: 3px solid var(--accent2);
}
.wb-meta {
  font-size: 0.75rem;
  color: var(--red);
  margin-top: 6px;
  font-family: "Noto Serif SC", serif;
}
.wb-empty {
  text-align: center;
  padding: 32px 16px;
  color: var(--text2);
  font-size: 1rem;
}
.wb-actions {
  display: flex;
  gap: 10px;
  padding: 12px 16px;
  border-top: 1px solid #f0e4d0;
}
.wb-actions .action-btn {
  flex: 1;
  padding: 12px 0;
  text-align: center;
}
.wn-item {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  padding: 12px 0;
  border-bottom: 1px solid #f0e4d0;
}
.wn-item:last-child {
  border-bottom: none;
}
.wn-icon {
  font-size: 1.6rem;
  flex-shrink: 0;
  margin-top: 2px;
}
.wn-desc {
  font-size: 0.85rem;
  color: var(--text2);
  margin-top: 3px;
  line-height: 1.6;
}
.diff-control {
  display: flex;
  background: var(--paper-alt);
  border-bottom: 1px solid #ddd0b8;
  padding: 8px 16px;
  gap: 8px;
  justify-content: center;
}
.diff-btn {
  flex: 1;
  max-width: 110px;
  border: none;
  background: transparent;
  color: var(--text2);
  padding: 7px 0;
  border-radius: 20px;
  font-size: 0.9rem;
  font-family: "Noto Serif SC", serif;
  cursor: pointer;
  transition: all 0.2s;
  font-weight: 700;
  min-height: 38px;
}
.diff-btn.active {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 2px 8px rgba(193, 59, 10, 0.3);
}
.game-area {
  padding: 16px;
  max-width: 480px;
  margin: 0 auto;
}
.progress-bar {
  display: flex;
  gap: 4px;
  margin-bottom: 20px;
  height: 6px;
}
.progress-dot {
  flex: 1;
  border-radius: 3px;
  height: 6px;
  background: #e0d0b8;
  transition: background 0.3s;
}
.progress-dot.done {
  background: var(--green);
}
.progress-dot.current {
  background: var(--accent);
  box-shadow: 0 0 8px rgba(193, 59, 10, 0.45);
}
.progress-dot.skip {
  background: var(--red);
  opacity: 0.55;
}
.idiom-display {
  display: flex;
  justify-content: center;
  gap: clamp(6px, 2.5vw, 14px);
  margin-bottom: 28px;
  position: relative;
}
.char-box {
  width: clamp(58px, 17vw, 80px);
  height: clamp(58px, 17vw, 80px);
  background: var(--card);
  border: 2.5px solid #e0d0b8;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--fs-char);
  font-weight: 900;
  color: var(--text);
  box-shadow: var(--shadow-sm);
  transition: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  position: relative;
  background-image:
    linear-gradient(rgba(160, 130, 90, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(160, 130, 90, 0.07) 1px, transparent 1px);
  background-size: 50% 50%;
}
.char-box.blank {
  border-color: var(--accent);
  border-style: dashed;
  background-color: #fff5ee;
  background-image:
    linear-gradient(rgba(193, 59, 10, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(193, 59, 10, 0.05) 1px, transparent 1px);
  background-size: 50% 50%;
  animation: blankPulse 2.5s ease-in-out infinite;
  cursor: pointer;
}
.char-box.blank.selected {
  border-style: solid;
  border-width: 3px;
  background-color: #ffeedd;
  transform: scale(1.1);
  box-shadow: 0 0 0 4px rgba(193, 59, 10, 0.18);
  animation: none;
}
.char-box.blank.selected::after {
  content: "";
  position: absolute;
  bottom: -9px;
  left: 50%;
  transform: translateX(-50%);
  border: 5px solid transparent;
  border-top-color: var(--accent);
}
.char-box.filled {
  border-color: var(--accent2);
  border-style: solid;
  background: linear-gradient(135deg, #fff5ee, #ffe8d0);
  color: var(--accent);
  animation: popIn 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}
.char-box.correct {
  border-color: var(--green);
  background: linear-gradient(135deg, #e8f5ee, #d4eddf);
  color: var(--green);
  animation: correctPop 0.4s ease;
}
.char-box.wrong {
  border-color: var(--red);
  background: var(--red-lt);
  color: var(--red);
  animation: shake 0.4s ease;
}
.char-box .pinyin-hint {
  position: absolute;
  top: -20px;
  font-size: 0.65rem;
  color: var(--text2);
  font-weight: 400;
  white-space: nowrap;
}
.options-grid {
  display: grid;
  grid-template-columns: repeat(4, clamp(52px, 13vw, 68px));
  gap: clamp(6px, 2vw, 10px);
  margin-bottom: 16px;
  justify-content: center;
}
.option-btn {
  aspect-ratio: 1;
  width: 100%;
  border: 2px solid #e0d0b8;
  background: var(--card);
  border-radius: 10px;
  font-size: var(--fs-opt);
  font-family: "Noto Serif SC", serif;
  font-weight: 700;
  color: var(--text);
  cursor: pointer;
  transition: all 0.15s;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-sm);
}
.option-btn:active {
  transform: scale(0.88);
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}
.option-btn.used {
  opacity: 0.28;
  pointer-events: none;
  background: #f5f0e8;
}
.option-btn.disabled {
  opacity: 0.15;
  pointer-events: none;
}
.action-bar {
  display: flex;
  gap: 10px;
  justify-content: center;
  margin-bottom: 16px;
  flex-wrap: wrap;
}
.action-btn {
  border: none;
  padding: 12px 28px;
  border-radius: 24px;
  font-size: 0.95rem;
  font-family: "Noto Serif SC", serif;
  cursor: pointer;
  transition: all 0.2s;
  min-height: 48px;
}
.action-btn.primary {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff;
  box-shadow: 0 2px 10px rgba(193, 59, 10, 0.3);
  flex: 1;
  max-width: 280px;
}
.action-btn.primary:active {
  transform: scale(0.97);
}
.action-btn.secondary {
  background: var(--card);
  color: var(--text2);
  border: 1.5px solid #e0d0b8;
}
.action-btn.secondary:active {
  transform: scale(0.95);
}
.result-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 20px;
  margin-top: 12px;
  box-shadow: var(--shadow-md);
  animation: slideUp 0.4s ease;
  border-top: 4px solid var(--green);
}
.result-card.wrong-result {
  border-top-color: var(--red);
}
.result-card h3 {
  font-size: 1.15rem;
  margin-bottom: 8px;
  font-family: "ZCOOL KuaiLe", cursive;
}
.result-card .idiom-word {
  font-size: clamp(1.6rem, 6vw, 2.2rem);
  font-weight: 900;
  color: var(--text);
  margin-bottom: 4px;
  letter-spacing: 4px;
}
.result-card .idiom-pinyin {
  font-size: 0.85rem;
  color: var(--text2);
  margin-bottom: 12px;
  letter-spacing: 1px;
}
.result-card .idiom-explain {
  font-size: 0.95rem;
  line-height: 1.8;
  color: #5d4e37;
  padding: 12px 12px 12px 16px;
  background: #fff8f0;
  border-radius: 8px;
  border-left: 3px solid var(--accent2);
}
.combo-toast {
  position: fixed;
  top: 72px;
  left: 50%;
  transform: translateX(-50%) translateY(-8px);
  background: var(--gold);
  color: #fff;
  border-radius: 24px;
  padding: 7px 20px;
  font-family: "ZCOOL KuaiLe", cursive;
  font-size: 1.05rem;
  box-shadow: var(--shadow-md);
  opacity: 0;
  pointer-events: none;
  z-index: 150;
  transition:
    opacity 0.25s,
    transform 0.25s;
  white-space: nowrap;
}
.combo-toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 200;
  padding: 20px;
}
.modal-overlay.show {
  display: flex;
}
.modal {
  background: var(--card);
  border-radius: 20px;
  overflow: hidden;
  max-width: 360px;
  width: 100%;
  animation: slideUp 0.3s ease;
  box-shadow: 0 8px 32px rgba(26, 16, 8, 0.2);
}
.modal-header {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff;
  padding: 22px 24px 18px;
  text-align: center;
}
.modal-header .streak-display {
  font-size: 3.5rem;
  font-weight: 900;
  font-family: "ZCOOL KuaiLe", cursive;
  line-height: 1;
}
.modal-header .streak-label {
  font-size: 0.9rem;
  opacity: 0.92;
  margin-top: 4px;
}
.modal-body {
  padding: 18px 20px 20px;
}
.modal .calendar {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 4px;
  margin-bottom: 14px;
}
.modal .cal-day {
  width: 100%;
  aspect-ratio: 1;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.72rem;
  background: var(--paper-alt);
  color: var(--text2);
}
.modal .cal-day.checked {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff;
  font-weight: 700;
}
.modal .cal-day.today {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}
.daily-goal {
  background: var(--paper-alt);
  border-radius: 10px;
  padding: 10px 14px;
  margin-bottom: 14px;
}
.daily-goal-label {
  font-size: 0.82rem;
  color: var(--text2);
  margin-bottom: 7px;
}
.daily-goal-bar {
  height: 8px;
  background: #ddd0b8;
  border-radius: 4px;
  overflow: hidden;
}
.daily-goal-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--green), #4caf50);
  border-radius: 4px;
  transition: width 0.5s ease;
}
.close-modal {
  display: block;
  width: 100%;
  border: none;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff;
  padding: 14px;
  font-size: 1rem;
  font-family: "Noto Serif SC", serif;
  cursor: pointer;
  min-height: 50px;
}
@keyframes popIn {
  0% {
    transform: scale(0.8);
    opacity: 0.5;
  }
  100% {
    transform: scale(1);
    opacity: 1;
  }
}
@keyframes correctPop {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.18);
  }
  100% {
    transform: scale(1);
  }
}
@keyframes shake {
  0%,
  100% {
    transform: translateX(0);
  }
  25% {
    transform: translateX(-7px);
  }
  75% {
    transform: translateX(7px);
  }
}
@keyframes slideUp {
  0% {
    transform: translateY(20px);
    opacity: 0;
  }
  100% {
    transform: translateY(0);
    opacity: 1;
  }
}
@keyframes blankPulse {
  0%,
  100% {
    box-shadow: 0 0 0 0 rgba(193, 59, 10, 0.08);
  }
  50% {
    box-shadow: 0 0 0 6px rgba(193, 59, 10, 0.13);
  }
}
@keyframes comboIn {
  0% {
    transform: scale(0.5);
    opacity: 0;
  }
  100% {
    transform: scale(1);
    opacity: 1;
  }
}
@media (max-width: 380px) {
  .header-title {
    font-size: 0.95rem;
    letter-spacing: 1px;
  }
  .icon-btn {
    min-width: 40px;
    min-height: 40px;
  }
}
@media (min-width: 600px) {
  .game-area {
    padding: 24px 32px;
  }
  .char-box {
    width: 88px;
    height: 88px;
  }
  .options-grid {
    gap: 16px;
  }
}