* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue", sans-serif;
  background: #f5f7fa;
  color: #2c3e50;
  -webkit-font-smoothing: antialiased;
}

.screen {
  max-width: 480px;
  margin: 0 auto;
  min-height: 100vh;
  padding: 24px 16px 40px;
}

.hidden {
  display: none !important;
}

/* ===== 通用 ===== */
.card {
  background: #fff;
  border-radius: 16px;
  box-shadow: 0 4px 20px rgba(47, 128, 237, 0.06);
}

.btn {
  border: none;
  border-radius: 999px;
  font-size: 17px;
  font-weight: 600;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

.btn:active {
  opacity: 0.85;
  transform: scale(0.98);
}

.btn-primary {
  background: linear-gradient(135deg, #2f80ed, #56a3f5);
  color: #fff;
  box-shadow: 0 8px 20px rgba(47, 128, 237, 0.28);
}

.btn-ghost {
  background: #fff;
  color: #2f80ed;
  border: 1px solid #d6e6fb;
}

.big {
  width: 100%;
  height: 52px;
}

/* ===== 首页 ===== */
.hero {
  background: linear-gradient(150deg, #2f80ed 0%, #56a3f5 55%, #6fc3f0 100%);
  border-radius: 20px;
  padding: 48px 24px 40px;
  text-align: center;
  color: #fff;
  box-shadow: 0 12px 30px rgba(47, 128, 237, 0.3);
}

.hero-emoji { font-size: 56px; line-height: 1; margin-bottom: 14px; }
.hero-title { font-size: 28px; font-weight: 700; letter-spacing: 1px; }
.hero-sub { font-size: 15px; opacity: 0.92; margin-top: 8px; }
.hero-tag {
  display: inline-block;
  margin-top: 16px;
  background: rgba(255,255,255,0.2);
  padding: 4px 16px;
  border-radius: 999px;
  font-size: 13px;
}

.actions {
  margin-top: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.section-title {
  margin: 28px 0 12px;
  font-size: 16px;
  font-weight: 700;
  color: #5a6b7d;
  padding-left: 4px;
}

.chapter-list { display: flex; flex-direction: column; gap: 12px; }

.chapter-item {
  display: flex;
  align-items: center;
  padding: 16px;
  background: #fff;
  border-radius: 16px;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(47, 128, 237, 0.06);
}
.chapter-item:active { background: #f7faff; }

.chapter-icon {
  font-size: 28px;
  width: 52px; height: 52px;
  line-height: 52px;
  text-align: center;
  background: #eef5fe;
  border-radius: 12px;
  margin-right: 14px;
  flex-shrink: 0;
}

.chapter-body { flex: 1; min-width: 0; }
.chapter-title { font-size: 17px; font-weight: 600; }
.chapter-desc { font-size: 13px; color: #8a9aab; margin-top: 3px; }
.chapter-arrow { font-size: 26px; color: #c3cfdc; }

.footer { margin-top: 28px; text-align: center; font-size: 12px; color: #b0bcc8; }

/* ===== 顶栏 ===== */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 4px 16px;
}
.chapter {
  font-size: 13px; color: #2f80ed;
  background: #eef5fe;
  padding: 5px 14px;
  border-radius: 999px;
  font-weight: 600;
}
.pageind { font-size: 13px; color: #8a9aab; }

/* ===== 阅读页 ===== */
.stage { display: flex; flex-direction: column; }
.picbox {
  width: 100%;
  background: #fff;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 6px 24px rgba(47,128,237,0.08);
  display: flex; align-items: center; justify-content: center;
}
.pic { width: 100%; display: block; }
.title { margin-top: 18px; font-size: 22px; font-weight: 700; }
.text { margin-top: 10px; font-size: 16px; line-height: 1.75; color: #4a5a6a; }

.controls {
  position: sticky;
  bottom: 0;
  margin-top: 20px;
  padding: 14px 16px;
  background: #fff;
  border-radius: 16px;
  box-shadow: 0 -2px 16px rgba(0,0,0,0.05);
}
.btnrow { display: flex; gap: 10px; }
.btnrow .btn { height: 48px; font-size: 15px; }
.nav { flex: 1; background: #f2f6fb; color: #5a6b7d; }
.play {
  flex: 1.2;
  background: linear-gradient(135deg,#2f80ed,#56a3f5);
  color: #fff;
  box-shadow: 0 6px 16px rgba(47,128,237,0.3);
}
.homelink {
  margin-top: 12px;
  text-align: center;
  font-size: 13px;
  color: #2f80ed;
  cursor: pointer;
}

/* ===== 答题 ===== */
.qcard { padding: 22px 18px; }
.qtext { font-size: 19px; font-weight: 700; line-height: 1.5; margin-bottom: 20px; }
.options { display: flex; flex-direction: column; gap: 12px; }
.opt {
  display: flex; align-items: center;
  padding: 14px;
  border: 1px solid #e8eef6;
  border-radius: 12px;
  background: #fbfcfe;
  cursor: pointer;
}
.opt-tag {
  width: 30px; height: 30px; line-height: 30px;
  text-align: center; border-radius: 50%;
  background: #eef2f7; color: #5a6b7d;
  font-size: 14px; font-weight: 700;
  margin-right: 12px; flex-shrink: 0;
}
.opt-text { font-size: 16px; color: #4a5a6a; }
.opt.correct { border-color: #22a06b; background: #e8f7ee; }
.opt.correct .opt-tag { background: #22a06b; color: #fff; }
.opt.wrong { border-color: #e5533c; background: #fdeeee; }
.opt.wrong .opt-tag { background: #e5533c; color: #fff; }

.explain {
  margin-top: 18px; padding: 16px;
  background: #f7f9fc; border-radius: 12px;
}
.explain-label { font-size: 15px; font-weight: 700; }
.explain-text { font-size: 14px; color: #5a6b7d; line-height: 1.6; margin-top: 8px; }
.nextbtn {
  margin-top: 16px; width: 100%; height: 48px;
  background: linear-gradient(135deg,#2f80ed,#56a3f5);
  color: #fff; border: none; border-radius: 999px;
  font-size: 16px; font-weight: 600; cursor: pointer;
}

/* ===== 弹层 ===== */
.overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.45);
  display: flex; align-items: center; justify-content: center;
  padding: 24px;
  z-index: 100;
}
.overlay-card {
  width: 100%; max-width: 400px;
  background: #fff; border-radius: 20px;
  padding: 32px 24px 20px;
  text-align: center;
  max-height: 86vh; overflow-y: auto;
}
.o-emoji { font-size: 60px; }
.o-title { font-size: 22px; font-weight: 700; margin-top: 12px; }
.o-sub { font-size: 14px; color: #8a9aab; margin-top: 8px; }
.o-score { font-size: 40px; font-weight: 800; color: #2f80ed; margin-top: 10px; }
.rhyme {
  margin-top: 18px; padding: 16px;
  background: #f7f9fc; border-radius: 12px;
  text-align: left;
  font-size: 15px; line-height: 1.9; color: #4a5a6a;
}
.rhyme b { color: #2f80ed; font-size: 13px; display: block; margin-bottom: 8px; }
.o-btns { margin-top: 20px; display: flex; gap: 10px; }
.o-btns .btn { flex: 1; height: 48px; font-size: 15px; }
.o-close { margin-top: 16px; font-size: 13px; color: #8a9aab; cursor: pointer; }