.page { min-height: 100vh; background: #000; padding-bottom: 200rpx; }
.nav-placeholder { width: 100%; }
.header { background: rgba(0,0,0,0.9); border-bottom: 2rpx solid rgba(255,255,255,0.05); }
.header-inner { display: flex; align-items: center; justify-content: space-between; padding: 24rpx 32rpx; }
.header-placeholder { width: 64rpx; }
.header-title { font-size: 36rpx; font-weight: 600; color: #00CED1; }
.header-btn { width: 64rpx; height: 64rpx; border-radius: 50%; background: #2c2c2e; display: flex; align-items: center; justify-content: center; font-size: 32rpx; }
.book-card { margin: 32rpx; padding: 32rpx; border-radius: 32rpx; background: linear-gradient(135deg, #1c1c1e 0%, #2c2c2e 100%); border: 2rpx solid rgba(0,206,209,0.2); display: flex; align-items: center; gap: 24rpx; }
.book-icon { width: 96rpx; height: 96rpx; border-radius: 24rpx; background: linear-gradient(135deg, #00CED1 0%, #20B2AA 100%); display: flex; align-items: center; justify-content: center; font-size: 48rpx; }
.book-info { flex: 1; }
.book-title { font-size: 32rpx; font-weight: 600; color: #fff; display: block; }
.book-desc { font-size: 22rpx; color: rgba(255,255,255,0.4); margin-top: 8rpx; display: block; }
.book-stat { text-align: right; }
.book-num { font-size: 40rpx; font-weight: 700; color: #00CED1; display: block; }
.book-label { font-size: 20rpx; color: rgba(255,255,255,0.4); }
.preface-row { margin: 0 32rpx 24rpx; padding: 24rpx 32rpx; border-radius: 24rpx; background: #1c1c1e; border: 2rpx solid rgba(255,255,255,0.05); display: flex; align-items: center; }
.preface-left { display: flex; align-items: center; gap: 24rpx; flex: 1; }
.preface-icon { width: 64rpx; height: 64rpx; border-radius: 16rpx; background: rgba(0,206,209,0.2); display: flex; align-items: center; justify-content: center; font-size: 32rpx; }
.preface-text { font-size: 28rpx; color: #fff; }
.tag-free { font-size: 22rpx; color: #00CED1; background: rgba(0,206,209,0.1); padding: 6rpx 16rpx; border-radius: 8rpx; margin-right: 16rpx; }
.arrow { font-size: 32rpx; color: rgba(255,255,255,0.4); }
.arrow.expanded { transform: rotate(90deg); }
.parts { margin: 0 32rpx 24rpx; }
.part-head { padding: 24rpx 32rpx; border-radius: 24rpx; background: #1c1c1e; border: 2rpx solid rgba(255,255,255,0.05); display: flex; align-items: center; }
.part-left { display: flex; align-items: center; gap: 24rpx; flex: 1; }
.part-num { width: 64rpx; height: 64rpx; border-radius: 16rpx; background: linear-gradient(135deg, #00CED1 0%, #20B2AA 100%); display: flex; align-items: center; justify-content: center; font-size: 28rpx; font-weight: 700; color: #fff; }
.part-info { }
.part-title { font-size: 28rpx; font-weight: 600; color: #fff; display: block; }
.part-subtitle { font-size: 20rpx; color: rgba(255,255,255,0.4); }
.part-count { font-size: 22rpx; color: rgba(255,255,255,0.4); margin-right: 16rpx; }
.part-body { margin-top: 16rpx; margin-left: 24rpx; padding: 16rpx; border-radius: 16rpx; background: rgba(28,28,30,0.5); border: 2rpx solid rgba(255,255,255,0.05); }
.chapter-block { margin-bottom: 24rpx; }
.chapter-block:last-child { margin-bottom: 0; }
.chapter-title { font-size: 24rpx; color: rgba(255,255,255,0.6); padding: 16rpx 0; border-bottom: 2rpx solid rgba(255,255,255,0.05); margin-bottom: 8rpx; }
.section-row { display: flex; align-items: center; padding: 20rpx 24rpx; border-bottom: 2rpx solid rgba(255,255,255,0.05); }
.section-row:last-child { border-bottom: none; }
.section-lock { font-size: 28rpx; margin-right: 16rpx; }
.section-text { flex: 1; font-size: 24rpx; color: #fff; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.section-text.locked { color: rgba(255,255,255,0.5); }
.section-tag { font-size: 20rpx; color: #00CED1; background: rgba(0,206,209,0.1); padding: 4rpx 12rpx; border-radius: 6rpx; margin-right: 8rpx; }
.section-tag.purchased { background: transparent; }
.section-price { font-size: 20rpx; color: rgba(255,255,255,0.4); margin-right: 8rpx; }
.appendix-block { margin: 0 32rpx 24rpx; padding: 24rpx; border-radius: 24rpx; background: #1c1c1e; border: 2rpx solid rgba(255,255,255,0.05); }
.appendix-label { font-size: 24rpx; font-weight: 500; color: rgba(255,255,255,0.5); display: block; margin-bottom: 16rpx; }
.appendix-item { display: flex; align-items: center; justify-content: space-between; padding: 20rpx 0; border-bottom: 2rpx solid rgba(255,255,255,0.05); }
.appendix-item:last-child { border-bottom: none; }
.appendix-title { font-size: 24rpx; color: rgba(255,255,255,0.8); }
.bottom-space { height: 40rpx; }