/* 背单词 App - 青绿主色 */
:root {
  --safe-top: env(safe-area-inset-top, 20px);
  --safe-bottom: env(safe-area-inset-bottom, 34px);
  --app-bg: #f0fdfa;
  --card-bg: #ffffff;
  --primary: #0d9488;
  --primary-light: #2dd4bf;
  --primary-bg: #ccfbf1;
}

body { -webkit-tap-highlight-color: transparent; }
.page { min-height: 100vh; padding-bottom: calc(80px + var(--safe-bottom)); }
.nav-bar { padding-top: var(--safe-top); }
.bottom-nav { padding-bottom: var(--safe-bottom); }
.card-shadow { box-shadow: 0 2px 12px rgba(0,0,0,.06); }
.word-card { transition: transform 0.25s ease; }
.word-card:active { transform: scale(0.98); }
.btn-primary { background: linear-gradient(135deg, #0d9488, #14b8a6); color: #fff; }
.btn-primary:active { opacity: 0.9; }
.icon { width: 24px; height: 24px; flex-shrink: 0; }
.icon-sm { width: 20px; height: 20px; }