@import url("https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@400;500;700&family=Noto+Sans+TC:wght@400;500;700&display=swap");

body {
  font-family: "Noto Sans TC", "Noto Sans JP", sans-serif;
  background-color: #f5f5f5;
}

.japanese-text {
  font-family: "Noto Sans JP", sans-serif;
}

.flat-card {
  background: #ffffff;
  border: 2px solid #d4d4d4;
  transition: border-color 0.2s ease, background-color 0.2s ease;
}

.flat-card:hover {
  background: #fafafa;
  border-color: #404040;
}

.play-button {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: #1a1a1a;
  border: 2px solid #404040;
  cursor: pointer;
  transition: background-color 0.2s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.play-button:hover {
  background: #404040;
}

.play-button:active {
  background: #000000;
}

.play-icon {
  width: 0;
  height: 0;
  border-left: 14px solid white;
  border-top: 9px solid transparent;
  border-bottom: 9px solid transparent;
  margin-left: 3px;
}

.play-button.playing {
  background: #ffffff;
  border-color: #1a1a1a;
}

.play-button.playing .play-icon {
  border: none;
  width: 14px;
  height: 14px;
  background: #1a1a1a;
  margin-left: 0;
}

.play-button.slow {
  background: #f5f5f5;
  border-color: #a3a3a3;
}

.play-button.slow:hover {
  background: #e5e5e5;
}

.play-button.slow:active {
  background: #d4d4d4;
}

.play-button.slow.playing {
  background: #ffffff;
  border-color: #1a1a1a;
}

.play-button.slow span {
  display: flex;
  align-items: center;
  justify-content: center;
}

.romaji-syllable {
  display: inline-block;
  background: linear-gradient(
    to bottom,
    transparent 0%,
    transparent 40%,
    #ffeb3b 40%,
    #ffeb3b 80%,
    transparent 80%
  );
  padding: 0 4px;
  margin: 0 2px;
  font-weight: 500;
}

/* 位置切換按鈕樣式 */
.position-toggle {
  padding: 8px 16px;
  border-radius: 8px;
  background: #ffffff;
  border: 2px solid #d4d4d4;
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 500;
  color: #404040;
  flex-shrink: 0;
  white-space: nowrap;
}

.position-toggle:hover {
  background: #fafafa;
  border-color: #404040;
}

.position-toggle:active {
  background: #f0f0f0;
}

/* 按鈕位置控制 */
.buttons-right .flex.items-start > div:first-child {
  order: 2;
}

.buttons-right .flex.items-start > div:last-child {
  order: 1;
}

/* 區段樣式 */
.section-container {
  margin-bottom: 48px;
}

.section-container:last-child {
  margin-bottom: 0;
}

.section-title {
  font-size: 24px;
  font-weight: 700;
  color: #1a1a1a;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 3px solid #d4d4d4;
}

.section-cards {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

/* 區段導航樣式 */
.section-nav {
  display: flex;
  gap: 8px;
  justify-content: center;
  padding: 16px 0;
  margin-bottom: 24px;
  border-bottom: 2px solid #d4d4d4;
  flex-wrap: wrap;
}

.section-nav-btn {
  padding: 8px 16px;
  background: #ffffff;
  border: 2px solid #d4d4d4;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 16px;
  font-weight: 500;
  color: #404040;
  white-space: nowrap;
}

.section-nav-btn:hover {
  background: #fafafa;
  border-color: #404040;
}

.section-nav-btn:active {
  background: #f0f0f0;
}

.section-nav-btn.active {
  background: #1a1a1a;
  color: #ffffff;
  border-color: #1a1a1a;
}

/* 手機版 RWD */
@media (max-width: 640px) {
  .section-nav {
    justify-content: flex-start;
    overflow-x: auto;
    flex-wrap: nowrap;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

  .section-nav::-webkit-scrollbar {
    display: none;
  }

  .section-nav-btn {
    flex-shrink: 0;
  }
}

/* 回到頂端按鈕 */
.scroll-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 56px;
  height: 56px;
  background: #1a1a1a;
  color: #ffffff;
  border: 2px solid #404040;
  border-radius: 50%;
  font-size: 24px;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.3s ease;
  opacity: 0;
  visibility: hidden;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.scroll-to-top.left {
  right: auto;
  left: 32px;
}

.scroll-to-top.show {
  opacity: 1;
  visibility: visible;
}

.scroll-to-top:hover {
  background: #404040;
  transform: translateY(-4px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
}

.scroll-to-top:active {
  background: #000000;
  transform: translateY(-2px);
}

@media (max-width: 640px) {
  .scroll-to-top {
    width: 48px;
    height: 48px;
    bottom: 24px;
    right: 24px;
    font-size: 20px;
  }

  .scroll-to-top.left {
    right: auto;
    left: 24px;
  }
}