/**
 * Page 03 · 大屏可读字号（英文例句 + 题目）
 */
#l13-book {
  --l13-fs-en: clamp(1.08rem, 1.2vw + 0.72rem, 1.42rem);
  --l13-fs-quiz-stem: clamp(1rem, 1.1vw + 0.65rem, 1.22rem);
  --l13-fs-quiz-opt: clamp(0.96rem, 1.05vw + 0.6rem, 1.14rem);
  --l13-fs-zh: clamp(0.9rem, 0.95vw + 0.5rem, 1.05rem);
}

@media (min-width: 900px) {
  #l13-book {
    --l13-fs-en: clamp(1.15rem, 1.35vw + 0.65rem, 1.5rem);
    --l13-fs-quiz-stem: clamp(1.05rem, 1.2vw + 0.58rem, 1.28rem);
    --l13-fs-quiz-opt: clamp(1rem, 1.1vw + 0.55rem, 1.2rem);
  }
}

#l13-book .en-line {
  font-size: var(--l13-fs-en) !important;
  line-height: 1.48 !important;
}

#l13-book .zh-hint {
  font-size: var(--l13-fs-zh);
  line-height: 1.45;
}

#l13-book .rule-box,
#l13-book .panel-lead {
  font-size: var(--l13-fs-zh);
}

/* 屏 1 · 总览 */
#l13-book .lesson-page[data-page="1"] .marker-banner .big {
  font-size: clamp(1.28rem, 2.6vw + 0.5rem, 1.85rem);
  line-height: 1.35;
}

#l13-book .lesson-page[data-page="1"] .marker-banner .sub {
  font-size: var(--l13-fs-zh);
}

/* 屏 2 · 锚点听音揭示 */
#l13-book .lesson-page[data-page="2"] .anchor-rule-hint {
  font-size: var(--l13-fs-zh);
}

#l13-book .lesson-page[data-page="2"] .anchor-scenario {
  font-size: var(--l13-fs-zh);
  line-height: 1.45;
}

#l13-book .lesson-page[data-page="2"] .anchor-reveal-slot .en-line {
  font-size: var(--l13-fs-en) !important;
}

#l13-book .lesson-page[data-page="2"] .anchor-use {
  font-size: var(--l13-fs-zh);
  line-height: 1.4;
}

/* 屏 3 · by 轮播 */
#l13-book .lesson-page[data-page="3"] .carousel-card .en-line {
  font-size: var(--l13-fs-en) !important;
}

/* 屏 4–6 · 例句列表 */
#l13-book .lesson-page[data-page="4"] .ex-item .en-line,
#l13-book .lesson-page[data-page="5"] .ex-item .en-line,
#l13-book .lesson-page[data-page="6"] .ex-item .en-line {
  font-size: var(--l13-fs-en) !important;
}

/* 屏 7 · 配对（字号随视口高度伸缩，配合无滚动铺满布局） */
#l13-book .lesson-page[data-page="7"] .match-chip {
  font-size: clamp(0.78rem, 1.15vh + 0.38rem, 1rem);
  line-height: 1.32;
}

#l13-book .lesson-page[data-page="7"] #match-right .match-chip-en {
  font-size: clamp(0.7rem, 1.05vh + 0.32rem, 0.88rem) !important;
  line-height: 1.28 !important;
}

#l13-book .lesson-page[data-page="7"] #match-right .match-chip-zh {
  font-size: clamp(0.62rem, 0.82vh + 0.2rem, 0.72rem) !important;
}

/* 屏 8 · 填空（每题一屏，随视口伸缩） */
#l13-book .lesson-page[data-page="8"] .fill-stem {
  font-size: clamp(0.92rem, 1.75vh + 0.42rem, 1.18rem) !important;
  line-height: 1.38 !important;
}

#l13-book .lesson-page[data-page="8"] .fill-opts button {
  font-size: clamp(0.8rem, 1.25vh + 0.35rem, 0.98rem) !important;
  min-height: clamp(38px, 5.5vh, 50px) !important;
  padding: clamp(0.28rem, 0.65vh, 0.45rem) clamp(0.4rem, 0.9vw, 0.65rem) !important;
}

/* 屏 9 · 快选（每题一屏 + 倒计时） */
#l13-book .lesson-page[data-page="9"] .quiz-stem {
  font-size: clamp(0.92rem, 1.75vh + 0.42rem, 1.18rem) !important;
  line-height: 1.38 !important;
}

#l13-book .lesson-page[data-page="9"] .opt-row button {
  font-size: clamp(0.8rem, 1.25vh + 0.35rem, 0.98rem) !important;
  line-height: 1.28 !important;
  min-height: clamp(38px, 5.5vh, 50px) !important;
  padding: clamp(0.28rem, 0.65vh, 0.45rem) clamp(0.45rem, 1vw, 0.7rem) !important;
}

#l13-book .quiz-item .fb,
#l13-book .fill-item .fb,
#l13-book #match-fb {
  font-size: var(--l13-fs-zh);
  line-height: 1.4;
}

/* 屏 10 · 合句 */
#l13-book .lesson-page[data-page="10"] .merge-clause .en-line {
  font-size: clamp(0.85rem, 1.4vh + 0.4rem, 1.08rem) !important;
}

#l13-book .lesson-page[data-page="10"] .merge-result .en-line {
  font-size: clamp(0.92rem, 1.55vh + 0.45rem, 1.15rem) !important;
}