:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --text: #1a1d23;
  --muted: #6b7280;
  --border: #e5e7eb;
  --accent: #2563eb;
  --accent-soft: #dbeafe;
  --danger: #dc2626;
  --shadow: 0 1px 3px rgba(0,0,0,.08);
}
[data-theme="dark"] {
  --bg: #0f172a;
  --card: #1e293b;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --border: #334155;
  --accent: #60a5fa;
  --accent-soft: #1e3a5f;
  --shadow: 0 1px 3px rgba(0,0,0,.4);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  transition: background .2s, color .2s;
}

.topbar {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; gap: 16px;
  padding: 12px 20px;
  background: var(--card);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}
.brand { font-weight: 700; font-size: 18px; }
.tabs { display: flex; gap: 4px; flex: 1; }
.tab {
  border: none; background: transparent; color: var(--muted);
  padding: 8px 14px; border-radius: 8px; cursor: pointer; font-size: 15px;
  display: inline-flex; align-items: center; gap: 6px;
}
.tab.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.badge { background: var(--accent); color: #fff; border-radius: 10px; padding: 1px 7px; font-size: 12px; }
.icon-btn { border: none; background: var(--card); cursor: pointer; font-size: 18px; padding: 6px 10px; border-radius: 8px; border: 1px solid var(--border); }

main { max-width: 720px; margin: 0 auto; padding: 24px 16px 80px; }
.view { display: none; }
.view.active { display: block; }

/* 查词 */
.search-wrap { position: relative; }
#search {
  width: 100%; padding: 16px 18px; font-size: 20px;
  border: 1px solid var(--border); border-radius: 12px;
  background: var(--card); color: var(--text); outline: none;
}
#search:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.dropdown {
  position: absolute; top: calc(100% + 6px); left: 0; right: 0;
  background: var(--card); border: 1px solid var(--border); border-radius: 12px;
  box-shadow: var(--shadow); max-height: 360px; overflow-y: auto; z-index: 20;
}
.autosave { display: flex; align-items: center; gap: 6px; color: var(--muted); font-size: 13px; margin-top: 10px; cursor: pointer; }
.autosave input { accent-color: var(--accent); }
.dropdown-item {
  padding: 10px 16px; cursor: pointer; display: flex; align-items: baseline; gap: 10px;
}
.dropdown-item.active, .dropdown-item:hover { background: var(--accent-soft); }
.dropdown-word { font-weight: 600; font-size: 16px; }
.dropdown-cn { color: var(--muted); font-size: 14px; flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.dropdown-tags { color: var(--accent); font-size: 12px; white-space: nowrap; }

.entry {
  margin-top: 20px; background: var(--card); border: 1px solid var(--border);
  border-radius: 14px; padding: 22px; box-shadow: var(--shadow);
}
.entry-head { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.entry-word { font-size: 30px; font-weight: 800; }
.entry-phonetic { color: var(--muted); font-size: 18px; }
.entry-tags { display: flex; gap: 6px; flex-wrap: wrap; }
.tag { background: var(--accent-soft); color: var(--accent); font-size: 12px; padding: 2px 8px; border-radius: 6px; }
.entry-actions { margin-left: auto; display: flex; gap: 8px; }
.btn {
  border: 1px solid var(--border); background: var(--card); color: var(--text);
  padding: 7px 14px; border-radius: 8px; cursor: pointer; font-size: 14px;
}
.btn:hover { border-color: var(--accent); }
.btn.primary { background: var(--accent); color: #fff; border-color: var(--accent); }
.btn.small { padding: 5px 10px; font-size: 13px; }
.btn.danger:hover { border-color: var(--danger); color: var(--danger); }

.entry-section { margin-top: 18px; }
.entry-section h3 { font-size: 14px; color: var(--muted); margin: 0 0 8px; text-transform: uppercase; letter-spacing: .5px; }
.entry-cn { font-size: 16px; line-height: 1.7; white-space: pre-wrap; }
.entry-en { font-size: 15px; line-height: 1.7; color: var(--text); }
.entry-en .pos { font-style: italic; color: var(--accent); margin-top: 8px; }
.entry-en .def { margin: 2px 0 0 16px; }
.entry-exchange { font-size: 13px; color: var(--muted); margin-top: 12px; }

/* 单词本 */
.toolbar { display: flex; gap: 10px; margin-bottom: 14px; flex-wrap: wrap; }
.toolbar input { flex: 1; min-width: 180px; padding: 12px 14px; border: 1px solid var(--border); border-radius: 10px; background: var(--card); color: var(--text); font-size: 15px; }
.toolbar-actions { display: flex; gap: 8px; }
.file-btn { cursor: pointer; }
.book-list { list-style: none; margin: 0; padding: 0; }
.book-item {
  display: flex; align-items: center; gap: 12px; padding: 14px 16px;
  background: var(--card); border: 1px solid var(--border); border-radius: 10px;
  margin-bottom: 8px; cursor: pointer;
}
.book-item:hover { border-color: var(--accent); }
.book-word { font-weight: 700; font-size: 17px; min-width: 110px; }
.book-cn { flex: 1; color: var(--muted); font-size: 14px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.book-del { border: none; background: transparent; color: var(--muted); cursor: pointer; font-size: 16px; padding: 4px 8px; border-radius: 6px; }
.book-del:hover { color: var(--danger); background: var(--accent-soft); }

/* 复习 */
.review-card { background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 32px; text-align: center; box-shadow: var(--shadow); }
.review-word { font-size: 34px; font-weight: 800; margin-bottom: 6px; }
.review-phonetic { color: var(--muted); margin-bottom: 20px; }
.review-answer { text-align: left; margin: 0 auto 20px; max-width: 480px; }
.review-answer.hidden { display: none; }
.review-actions { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }

/* 覆盖层 / 提示 */
.overlay { position: fixed; inset: 0; background: rgba(0,0,0,.5); display: flex; align-items: center; justify-content: center; z-index: 100; }
.login-box { background: var(--card); padding: 28px; border-radius: 14px; width: 90%; max-width: 320px; display: flex; flex-direction: column; gap: 12px; }
.login-box h2 { margin: 0 0 4px; }
.login-box input { padding: 12px 14px; border: 1px solid var(--border); border-radius: 8px; background: var(--bg); color: var(--text); font-size: 15px; }
.error { color: var(--danger); font-size: 13px; margin: 0; }

.toast {
  position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%);
  background: var(--text); color: var(--bg); padding: 10px 18px; border-radius: 8px;
  font-size: 14px; z-index: 200; opacity: 0; transition: opacity .2s;
}
.toast.show { opacity: 1; }

.empty { color: var(--muted); text-align: center; padding: 60px 20px; line-height: 1.8; }
.hint { font-size: 13px; color: var(--muted); }
.hidden { display: none !important; }

@media (max-width: 480px) {
  .entry-word { font-size: 26px; }
  .book-word { min-width: 88px; }
}