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

/* ===== 主题变量（与词典/学习站一致）===== */
body[data-theme="white"] {
  --bg: linear-gradient(135deg, #f0f4ff 0%, #e8f4fd 100%);
  --card-bg: #ffffff; --text: #1f2937; --sub: #6b7280;
  --input-bg: #f3f4f6; --input-text: #374151;
  --btn-bg: #2563eb; --btn-text: #ffffff; --btn-hover: #1d4ed8;
  --phonetic: #7c3aed; --pinyin: #b45309; --pos: #059669;
  --tag-bg: #eff6ff; --tag-text: #1d4ed8; --tag-border: #bfdbfe;
  --exchange: #6b7280; --def: #374151; --meta: #9ca3af;
  --shadow: rgba(31,41,55,.08); --shadow-item: rgba(31,41,55,.06);
  --btn-border: #e5e7eb; --btn-active: #dbeafe;
  --topbar-bg: rgba(255,255,255,.86);
}
body[data-theme="black"] {
  --bg: #141414;
  --card-bg: #1f1f1f; --text: #f3f4f6; --sub: #9ca3af;
  --input-bg: #2a2a2a; --input-text: #e5e7eb;
  --btn-bg: #3b82f6; --btn-text: #ffffff; --btn-hover: #2563eb;
  --phonetic: #a78bfa; --pinyin: #f59e0b; --pos: #34d399;
  --tag-bg: #1e293b; --tag-text: #93c5fd; --tag-border: #334155;
  --exchange: #9ca3af; --def: #d1d5db; --meta: #6b7280;
  --shadow: rgba(0,0,0,.4); --shadow-item: rgba(0,0,0,.3);
  --btn-border: #333; --btn-active: #2b3a52;
  --topbar-bg: rgba(20,20,20,.86);
}
body[data-theme="green"] {
  --bg: #c7edcc;
  --card-bg: #ddf2df; --text: #2c4834; --sub: #55705c;
  --input-bg: #e7f6e9; --input-text: #2f4f3a;
  --btn-bg: #5aa469; --btn-text: #f2faf3; --btn-hover: #4a9258;
  --phonetic: #4f7a5c; --pinyin: #8a7a3c; --pos: #4f7a5c;
  --tag-bg: #e2f1e3; --tag-text: #3e6b4a; --tag-border: #bfdcc2;
  --exchange: #55705c; --def: #3a5c45; --meta: #6b8a73;
  --shadow: rgba(46,75,55,.12); --shadow-item: rgba(46,75,55,.08);
  --btn-border: #b6d9bb; --btn-active: #c4e5c9;
  --topbar-bg: rgba(221,242,223,.86);
}
body[data-theme="gray"] {
  --bg: #3b3a38;
  --card-bg: #464442; --text: #d4d0ca; --sub: #9e9a93;
  --input-bg: #524f4c; --input-text: #c9c6c1;
  --btn-bg: #6b655d; --btn-text: #efece7; --btn-hover: #7a736a;
  --phonetic: #b3a88f; --pinyin: #c2b280; --pos: #b3a88f;
  --tag-bg: #4a4844; --tag-text: #b8b0a4; --tag-border: #5a574f;
  --exchange: #9e9a93; --def: #b5b1ab; --meta: #8a867f;
  --shadow: rgba(0,0,0,.25); --shadow-item: rgba(0,0,0,.2);
  --btn-border: #55524d; --btn-active: #57534e;
  --topbar-bg: rgba(70,68,66,.86);
}

/* ===== 基础 ===== */
body {
  font-family: "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  background: var(--bg); min-height: 100vh; color: var(--text);
}
.container { max-width: 720px; margin: 0 auto; padding: 18px 20px 80px; }

/* ===== 顶部（固定 + 滚动缩小）===== */
.topbar {
  position: sticky; top: 0; z-index: 20;
  background: var(--topbar-bg);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  padding: 18px 20px 14px;
  transition: padding .25s ease, box-shadow .25s ease;
  border-bottom: 1px solid transparent;
}
.topbar.compact { padding: 8px 20px; box-shadow: 0 4px 16px var(--shadow); border-bottom-color: var(--btn-border); }
.brand-row { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 8px; }
.brand { font-size: 24px; transition: font-size .25s ease; }
.topbar.compact .brand { font-size: 17px; }
.brand-actions { display: flex; align-items: center; gap: 8px; }
.subtitle { text-align: center; color: var(--sub); font-size: 13px; margin-bottom: 10px; transition: all .25s ease; }
.topbar.compact .subtitle { opacity: 0; height: 0; margin: 0; overflow: hidden; }
.search-box { display: flex; gap: 8px; background: var(--card-bg); padding: 10px; border-radius: 14px; box-shadow: 0 8px 24px var(--shadow); transition: padding .25s ease; }
.topbar.compact .search-box { padding: 6px; }
.search-box input { flex: 1; border: none; outline: none; font-size: 16px; padding: 10px 12px; border-radius: 8px; background: var(--input-bg); color: var(--input-text); transition: all .25s ease; }
.topbar.compact .search-box input { padding: 7px 10px; font-size: 14px; }
.search-box select { border: none; outline: none; background: var(--input-bg); border-radius: 8px; padding: 0 8px; font-size: 14px; color: var(--input-text); }
.search-box button { border: none; background: var(--btn-bg); color: var(--btn-text); padding: 0 22px; border-radius: 8px; font-size: 15px; cursor: pointer; transition: all .25s ease; }
.topbar.compact .search-box button { padding: 0 14px; font-size: 13px; }
.search-box button:hover { background: var(--btn-hover); }

/* ===== 主题选择器 ===== */
.theme-picker { position: relative; }
.theme-trigger {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--card-bg); color: var(--text);
  border: 1px solid var(--btn-border); border-radius: 999px;
  padding: 5px 12px; font-size: 13px; cursor: pointer;
  box-shadow: 0 2px 8px var(--shadow);
}
.theme-trigger:hover { opacity: .95; }
.theme-dot { width: 14px; height: 14px; border-radius: 50%; border: 1px solid rgba(128,128,128,.4); }
.theme-arrow { font-size: 11px; color: var(--sub); }
.theme-menu {
  position: absolute; top: calc(100% + 8px); right: 0;
  background: var(--card-bg); border: 1px solid var(--btn-border); border-radius: 12px;
  box-shadow: 0 10px 30px var(--shadow); padding: 6px; z-index: 30; min-width: 190px;
  display: none;
}
.theme-menu.open { display: block; }
.theme-option {
  display: flex; align-items: center; gap: 10px; width: 100%;
  background: transparent; border: none; border-radius: 8px; padding: 8px 10px;
  font-size: 13px; color: var(--text); cursor: pointer; text-align: left;
}
.theme-option:hover { background: var(--btn-active); }
.theme-option .dot { width: 16px; height: 16px; border-radius: 50%; border: 1px solid rgba(128,128,128,.4); flex: none; }
.dot-white { background: #f0f4ff; }
.dot-black { background: #141414; }
.dot-green { background: #c7edcc; }
.dot-gray { background: #3b3a38; }

/* ===== 主题浏览 ===== */
.kw-browse { display: block; }
.kw-title { color: var(--sub); font-size: 13px; margin: 6px 2px 8px; }
.kw-browse input {
  width: 100%; border: 1px solid var(--btn-border); outline: none;
  background: var(--card-bg); color: var(--input-text);
  border-radius: 10px; padding: 8px 12px; font-size: 13px; margin-bottom: 10px;
}
.kw-cloud { display: flex; flex-wrap: wrap; gap: 8px; }
.kw-chip {
  border: 1px solid var(--tag-border); background: var(--tag-bg); color: var(--tag-text);
  border-radius: 999px; padding: 4px 12px; font-size: 13px; cursor: pointer;
  transition: all .15s ease;
}
.kw-chip:hover { transform: translateY(-1px); box-shadow: 0 4px 10px var(--shadow); }
.kw-chip.sel { background: var(--btn-bg); color: var(--btn-text); border-color: var(--btn-bg); }

/* ===== 结果 ===== */
.status { margin: 16px 4px 8px; font-size: 14px; color: var(--sub); min-height: 20px; }
.results { list-style: none; }
.item { background: var(--card-bg); border-radius: 12px; padding: 16px 18px; margin-bottom: 12px; box-shadow: 0 4px 14px var(--shadow-item); }
.word { font-size: 19px; font-weight: 700; color: var(--text); }
.word mark { background: #fde68a; color: #92400e; padding: 0 2px; border-radius: 3px; }
body[data-theme="black"] .word mark { background: #78350f; color: #fcd34d; }
body[data-theme="green"] .word mark { background: #fde68a; color: #8a5a00; }
body[data-theme="gray"] .word mark { background: #57534e; color: #fde68a; }
.tags { margin-top: 7px; }
.tag { display: inline-block; background: var(--tag-bg); color: var(--tag-text); border: 1px solid var(--tag-border); border-radius: 999px; padding: 1px 10px; font-size: 12px; margin-right: 6px; }
.def { margin-top: 7px; line-height: 1.7; color: var(--def); font-size: 15px; }
.ex { margin-top: 6px; font-size: 13px; color: var(--exchange); }
.ex::before { content: "例句："; color: var(--meta); }
.meta { margin-top: 8px; font-size: 12px; color: var(--meta); }
.footer { text-align: center; margin-top: 30px; padding-bottom: 26px; color: var(--meta); font-size: 14px; letter-spacing: 1px; }

/* ===== 回到顶部 ===== */
.backtop {
  position: fixed; bottom: 26px; right: 26px; z-index: 50;
  width: 44px; height: 44px; border-radius: 50%; border: none;
  background: var(--btn-bg); color: var(--btn-text); font-size: 18px; cursor: pointer;
  box-shadow: 0 6px 18px var(--shadow);
  opacity: 0; transform: translateY(12px); transition: all .25s ease;
}
.backtop.show { opacity: 1; transform: translateY(0); }
.backtop:hover { background: var(--btn-hover); }

@media (max-width: 520px) {
  .search-box { flex-wrap: wrap; }
  .search-box select { order: 3; flex: 1; padding: 10px; }
  .search-box button { flex: 1; }
  .backtop { bottom: 18px; right: 18px; }
}