/* ========== 快乐旅行英语 · 全局样式 ========== */
:root {
  --coral: #ff6b6b;
  --orange: #ffa502;
  --sun: #ffd93d;
  --mint: #2ed573;
  --teal: #1bc6b4;
  --sea: #54a0ff;
  --violet: #9b59b6;
  --ink: #2d3436;
  --ink-soft: #636e72;
  --bg: #fff8f0;
  --card: #ffffff;
  --radius: 18px;
  --shadow: 0 8px 24px rgba(45, 52, 54, 0.08);
}

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

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  background: linear-gradient(160deg, #fff8f0 0%, #eef6ff 100%);
  background-attachment: fixed;
  color: var(--ink);
  line-height: 1.7;
  min-height: 100vh;
}

/* ---------- 顶部导航 ---------- */
header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 2px solid var(--sun);
  padding: 0 20px;
}
.nav {
  max-width: 1080px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
  padding: 12px 0;
}
.brand {
  font-size: 22px;
  font-weight: 800;
  background: linear-gradient(135deg, var(--coral), var(--sea));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-right: 16px;
  white-space: nowrap;
}
.brand .sub { font-size: 12px; color: var(--ink-soft); font-weight: 500; margin-left: 6px; }
.nav a {
  text-decoration: none;
  color: var(--ink-soft);
  font-weight: 600;
  padding: 8px 14px;
  border-radius: 999px;
  transition: all 0.2s;
  font-size: 15px;
}
.nav a:hover { color: var(--coral); background: #fff0f0; }
.nav a.active { background: var(--sea); color: #fff; }

/* ---------- 通用布局 ---------- */
main { max-width: 1080px; margin: 0 auto; padding: 28px 20px 60px; }
.page-title { font-size: 30px; font-weight: 800; margin-bottom: 6px; }
.page-sub { color: var(--ink-soft); margin-bottom: 24px; font-size: 16px; }

/* ---------- 卡片 ---------- */
.card {
  background: var(--card);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 20px;
  border-top: 6px solid var(--sea);
}
.card:hover { transform: translateY(-3px); box-shadow: 0 12px 30px rgba(45,52,54,0.12); }
.card { transition: all 0.25s; }

.grid { display: grid; gap: 18px; }
.grid-2 { grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); }

/* 场景卡片 */
.scene-card { text-decoration: none; color: inherit; display: block; }
.scene-card .icon { font-size: 40px; margin-bottom: 8px; }
.scene-card h3 { font-size: 20px; margin-bottom: 6px; }
.scene-card p { color: var(--ink-soft); font-size: 14px; }

/* ---------- 按钮 / 徽章 ---------- */
.btn {
  display: inline-block;
  border: none;
  border-radius: 999px;
  padding: 10px 20px;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  color: #fff;
  background: var(--sea);
  transition: all 0.2s;
}
.btn:hover { opacity: 0.88; transform: translateY(-2px); }
.btn-sun { background: var(--sun); color: var(--ink); }
.btn-coral { background: var(--coral); }

.badge {
  display: inline-block;
  padding: 3px 12px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 700;
  background: #eef3ff;
  color: var(--sea);
}

/* ---------- 句型卡片 ---------- */
.phrase {
  background: #fafcff;
  border-radius: 14px;
  padding: 14px 16px;
  margin-bottom: 12px;
  border-left: 5px solid var(--sea);
  display: flex;
  align-items: center;
  gap: 12px;
}
.phrase .en { font-size: 18px; font-weight: 700; color: var(--sea); }
.phrase .cn { color: var(--ink-soft); font-size: 15px; }
.phrase .info { flex: 1; }

/* 朗读按钮 */
.speak {
  width: 42px; height: 42px;
  border-radius: 50%;
  border: none;
  background: linear-gradient(135deg, var(--sun), var(--coral));
  color: #fff;
  font-size: 18px;
  cursor: pointer;
  flex-shrink: 0;
  transition: all 0.2s;
  box-shadow: 0 4px 10px rgba(255, 107, 107, 0.3);
}
.speak:hover { transform: scale(1.1); }
.speak:active { transform: scale(0.95); }

/* ---------- 单词卡片（翻转） ---------- */
.flip-area { perspective: 1000px; }
.flip-card {
  position: relative;
  width: 100%;
  height: 200px;
  cursor: pointer;
  transition: transform 0.6s;
  transform-style: preserve-3d;
}
.flip-card.flipped { transform: rotateY(180deg); }
.flip-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  border-radius: 18px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 16px;
  text-align: center;
}
.flip-front { background: linear-gradient(135deg, var(--sea), var(--violet)); color: #fff; }
.flip-front .word { font-size: 28px; font-weight: 800; }
.flip-front .hint { font-size: 13px; opacity: 0.85; margin-top: 8px; }
.flip-back { background: #fff; border: 2px solid var(--sea); transform: rotateY(180deg); }
.flip-back .cn { font-size: 24px; font-weight: 800; color: var(--coral); }
.flip-back .sample { color: var(--ink-soft); font-size: 13px; margin-top: 6px; }
.flip-back .speak { margin-top: 12px; }

/* ---------- 对话 ---------- */
.dlg {
  display: flex;
  gap: 12px;
  margin-bottom: 14px;
  align-items: flex-start;
}
.dlg .who {
  width: 46px; height: 46px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; color: #fff; flex-shrink: 0;
}
.dlg.traveler .who { background: var(--sea); }
.dlg.local .who { background: var(--coral); }
.dlg .bubble {
  flex: 1;
  background: #fff;
  border-radius: 14px;
  padding: 12px 16px;
  box-shadow: var(--shadow);
}
.dlg .en { font-size: 17px; font-weight: 700; color: var(--ink); }
.dlg .cn { color: var(--ink-soft); font-size: 14px; margin-top: 4px; }
.dlg .speak { width: 34px; height: 34px; font-size: 14px; margin-top: 4px; }

/* ---------- 速查手册 ---------- */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; margin-top: 12px; }
th, td { padding: 10px 12px; text-align: left; font-size: 15px; }
th { background: linear-gradient(135deg, var(--sea), var(--teal)); color: #fff; }
tr:nth-child(even) { background: #f4f9ff; }
td .speak { width: 30px; height: 30px; font-size: 13px; }

/* ---------- 每日一句 ---------- */
.daily {
  background: linear-gradient(135deg, var(--coral), var(--violet));
  color: #fff;
  border-radius: 18px;
  padding: 22px;
  text-align: center;
  box-shadow: var(--shadow);
  margin-bottom: 26px;
}
.daily .label { font-size: 13px; opacity: 0.9; }
.daily .en { font-size: 24px; font-weight: 800; margin: 6px 0; }
.daily .cn { font-size: 16px; opacity: 0.95; }

/* ---------- 页脚 ---------- */
footer {
  text-align: center;
  color: var(--ink-soft);
  font-size: 13px;
  padding: 24px;
}

/* ---------- 响应式 ---------- */
@media (max-width: 640px) {
  .page-title { font-size: 24px; }
  .nav { justify-content: center; }
  .brand { margin-right: 0; }
}