/* ===== 英语乐园 共用样式 ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --orange: #ff8a3d;
  --orange-dark: #f0711e;
  --blue: #4a90e2;
  --purple: #8b6cef;
  --green: #4cc38a;
  --ink: #33303e;
  --gray: #7a7585;
  --card: #fff;
}

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  background: linear-gradient(160deg, #fff2e0 0%, #ffe9f3 55%, #eaf4ff 100%);
  color: var(--ink);
  line-height: 1.7;
  min-height: 100vh;
  -webkit-tap-highlight-color: transparent;
}

/* 顶栏 */
.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px clamp(16px, 5vw, 48px);
  background: rgba(255, 249, 242, .94);
  backdrop-filter: blur(8px);
  border-bottom: 2px solid #ffe9d1;
}

.topbar-title { font-size: 20px; font-weight: 900; }

.topbar-nav { display: flex; gap: 10px; }

.tab-link {
  padding: 8px 18px;
  border-radius: 999px;
  background: #fff;
  color: var(--gray);
  text-decoration: none;
  font-size: 15px;
  font-weight: 700;
  box-shadow: 0 4px 12px rgba(120, 90, 150, .10);
  transition: .2s;
}

.tab-link:hover { color: var(--orange); transform: translateY(-2px); }

.tab-link.active { background: var(--orange); color: #fff; box-shadow: 0 6px 16px rgba(255, 138, 61, .35); }

.page { max-width: 880px; margin: 0 auto; padding: clamp(24px, 5vw, 48px) clamp(16px, 5vw, 32px) 60px; }

.page-head { text-align: center; margin-bottom: 28px; }

.page-head h1 { font-size: clamp(24px, 4.4vw, 34px); font-weight: 900; margin-bottom: 8px; }

.page-head p { color: var(--gray); font-size: 15px; }

/* 通用按钮 */
.btn {
  padding: 12px 30px;
  border: none;
  border-radius: 999px;
  background: var(--orange);
  color: #fff;
  font-size: 16px;
  font-weight: 800;
  font-family: inherit;
  cursor: pointer;
  box-shadow: 0 8px 20px rgba(255, 138, 61, .35);
  transition: .2s;
}

.btn:hover { background: var(--orange-dark); transform: translateY(-2px); }

.btn:disabled { background: #dcd8e0; box-shadow: none; cursor: not-allowed; transform: none; }

.btn-ghost {
  background: #fff;
  color: var(--ink);
  box-shadow: 0 4px 14px rgba(120, 90, 150, .12);
}

.btn-ghost:hover { background: #fff; color: var(--orange); }

/* 单元筛选条 */
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  margin-bottom: 26px;
}

.chip {
  padding: 9px 20px;
  border: 2px solid #ffe0c2;
  border-radius: 999px;
  background: #fff;
  color: var(--gray);
  font-size: 14px;
  font-weight: 700;
  font-family: inherit;
  cursor: pointer;
  transition: .2s;
}

.chip:hover { border-color: var(--orange); color: var(--orange); }

.chip.active { background: var(--orange); border-color: var(--orange); color: #fff; box-shadow: 0 6px 16px rgba(255, 138, 61, .32); }

/* 空状态 */
.empty {
  text-align: center;
  color: var(--gray);
  padding: 50px 20px;
  font-size: 16px;
}

@media (max-width: 640px) {
  .topbar { flex-direction: column; gap: 10px; padding: 12px 16px; }
  .topbar-title { font-size: 18px; }
  .tab-link { padding: 7px 14px; font-size: 14px; }
}