@font-face{
  font-family:'Friends';
  src:url('fonts/FRIENDS.TTF') format('truetype');
  font-weight:400 700;
  font-display:swap;
}
:root{
  --bg1:#fff3e6; --bg2:#ffe0c7;
  --purple:#6d4aa6; --orange:#ef7d3b; --teal:#2bb6a8;
  --ink:#3a2a1f; --muted:#8a7a6d;
  --card-front:#ffffff; --card-back:#fdeede;
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent;}
html,body{margin:0;padding:0;height:100%;}
body{
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Helvetica Neue",Arial,sans-serif;
  background:linear-gradient(160deg,var(--bg1),var(--bg2));
  color:var(--ink);
  min-height:100vh;
  display:flex;justify-content:center;
}
.app{width:100%;max-width:430px;min-height:100vh;display:flex;flex-direction:column;padding:0 18px 28px;}
.topbar{text-align:center;padding:26px 0 10px;}
.logo{
  font-family:'Friends','Caveat',cursive,Bradley Hand,-apple-system,BlinkMacSystemFont,sans-serif;
  font-weight:700;
  font-size:36px;
  color:var(--ink);
  display:flex;
  align-items:center;
  justify-content:center;
  gap:2px;
  line-height:1;
}
.logo .ltr{display:inline-block;line-height:1;}
.logo .dot{
  width:7px;
  height:7px;
  border-radius:50%;
  align-self:center;
  margin:0 2px;
  box-shadow:0 1px 2px rgba(0,0,0,.12);
}
.logo .dot.red{background:#e84a5f;}
.logo .dot.yellow{background:#f9c80e;}
.logo .dot.blue{background:#3a86ff;}
.subtitle{color:var(--muted);font-size:14px;margin-top:4px;}

/* flip card */
.stage{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:18px;padding-top:10px;padding-bottom:56px;}
.flip-card{width:100%;height:400px;perspective:1200px;cursor:pointer;}
.flip-inner{position:relative;width:100%;height:100%;transition:transform .6s;transform-style:preserve-3d;}
.flip-card.flipped .flip-inner{transform:rotateY(180deg);}
.flip-face{position:absolute;inset:0;backface-visibility:hidden;-webkit-backface-visibility:hidden;
  border-radius:22px;padding:34px 24px 24px;display:flex;flex-direction:column;
  box-shadow:0 14px 30px rgba(120,70,30,.18);overflow:hidden;}
.flip-front{background:linear-gradient(155deg,#fff,#fff6ee);border:2px solid #ffe2c4;}
.flip-back{background:linear-gradient(155deg,#fdeede,#fcd9b8);transform:rotateY(180deg);border:2px solid var(--orange);}
.face-header{display:flex;align-items:center;justify-content:space-between;flex:none;}
.face-header-right{display:flex;align-items:center;gap:10px;}
.face-tag{font-size:12px;letter-spacing:3px;color:var(--orange);font-weight:700;}
.flip-back .face-tag{color:var(--purple);}
/* 题卡正面（中文题目 / 英文 Quiz）字号调小两字号：20px → 18px；文本左对齐（不居中）；背面答案保持 20px 居中不变 */
.flip-front .face-text{font-size:18px;text-align:left;justify-content:flex-start;}
.face-text{flex:1;display:flex;align-items:center;justify-content:center;text-align:center;
  font-size:20px;line-height:1.5;font-weight:600;padding:6px 4px;overflow:auto;white-space:pre-wrap;word-break:break-word;}
.face-hint{text-align:center;color:var(--muted);font-size:13px;flex:none;}

/* 正面底部左侧 Hint：默认打码，点击切换明文；表面上看起来就是一行普通灰字 */
.front-hint{margin-top:auto;align-self:flex-start;text-align:left;
  font-size:13px;line-height:1.5;color:var(--muted);cursor:pointer;user-select:none;
  flex:none;padding-top:10px;letter-spacing:1px;word-break:break-word;white-space:pre-wrap;}
.front-hint.revealed{color:var(--ink);cursor:pointer;}

/* 背面底部左侧 Note */
.back-note{margin-top:auto;align-self:flex-start;text-align:left;
  font-size:13px;line-height:1.5;color:var(--muted);flex:none;padding-top:10px;
  word-break:break-word;white-space:pre-wrap;}

.front-stars{text-align:right;color:var(--orange);font-size:12px;letter-spacing:2px;font-weight:700;flex:none;}
.meta-box{display:flex;flex-direction:column;gap:7px;font-size:13px;color:var(--muted);
  overflow:auto;flex:none;max-height:140px;}
.meta-box img{max-width:100%;max-height:120px;border-radius:10px;align-self:center;}
.meta-box .meta-row{line-height:1.4;}
.meta-box .meta-row strong{color:var(--ink);}

/* 翻页方向动画：
   下一张 → 当前卡向左下倒下、移出页面；新卡从右侧滑入。
   上一张 → 当前卡平滑向右划去；新卡从左下反方向进入。
   退场终点与进场起点完全一致，且换内容在卡片屏外（不可见）时完成，故不会露出答案背面。 */
.flip-card.exit-next{transform-origin:bottom left;animation:exitNext .42s cubic-bezier(.55,.06,.68,.19) forwards;}
.flip-card.exit-prev{transform-origin:center right;animation:exitPrev .42s cubic-bezier(.55,.06,.68,.19) forwards;}
.flip-card.enter-next{animation:enterNext .46s cubic-bezier(.22,1,.36,1) forwards;}
.flip-card.enter-prev{animation:enterPrev .46s cubic-bezier(.22,1,.36,1) forwards;}
@keyframes exitNext{
  0%{transform:translate(0,0) rotate(0);opacity:1;}
  100%{transform:translate(-60%,65%) rotate(-16deg);opacity:0;}
}
@keyframes exitPrev{
  0%{transform:translate(0,0) rotate(0);opacity:1;}
  100%{transform:translate(60%,0) rotate(6deg);opacity:0;}
}
@keyframes enterNext{
  0%{transform:translate(60%,0) rotate(6deg);opacity:0;}
  100%{transform:translate(0,0) rotate(0);opacity:1;}
}
@keyframes enterPrev{
  0%{transform:translate(-60%,65%) rotate(-16deg);opacity:0;}
  100%{transform:translate(0,0) rotate(0);opacity:1;}
}

.counter{color:var(--muted);font-size:14px;}

/* 答题页操作区：位于卡片下方、页码之下两行 */
.quiz-actions{display:flex;flex-direction:column;gap:10px;width:100%;margin-top:14px;}
.main-actions{display:flex;gap:12px;}
.btn{flex:1;border:none;border-radius:14px;padding:14px;font-size:16px;font-weight:700;cursor:pointer;text-decoration:none;display:flex;align-items:center;justify-content:center;text-align:center;}
.btn-primary{background:var(--purple);color:#fff;}
.btn-ghost{background:rgba(255,255,255,.7);color:var(--purple);border:1px solid #e6d3f2;}
a.btn,a.btn:hover,a.btn:visited,a.btn:active{text-decoration:none;}

.admin-link{display:block;text-align:center;margin-top:16px;color:var(--purple);text-decoration:none;font-size:14px;font-weight:600;}

/* 底部样式切换：浅色 | 深色 居中显示（中文|En 已移至题卡右上角） */
.toggles-row{display:flex;align-items:center;justify-content:center;width:100%;}
.theme-toggle{display:flex;align-items:center;gap:8px;}
.link-btn{background:none;border:none;cursor:pointer;color:var(--ink);font-size:14px;font-weight:400;font-family:inherit;padding:0;line-height:inherit;}
.link-btn.active{color:var(--purple);font-weight:700;text-decoration:none;}
.toggle-sep{color:var(--muted);user-select:none;}

.lang-toggle{display:flex;align-items:center;gap:8px;}
.lang-btn{background:none;border:none;cursor:pointer;color:var(--ink);font-size:14px;font-weight:400;font-family:inherit;padding:0;line-height:inherit;}
.lang-btn.active{color:var(--purple);font-weight:700;text-decoration:none;}
.lang-sep{color:var(--muted);user-select:none;}

/* difficulty modal */
.modal{position:fixed;inset:0;background:rgba(58,42,31,.55);backdrop-filter:blur(2px);
  display:flex;align-items:center;justify-content:center;padding:24px;z-index:50;}
.modal.hidden{display:none;}
.modal-card{background:#fff;border-radius:22px;width:100%;max-width:360px;padding:26px 22px;
  box-shadow:0 20px 50px rgba(80,40,10,.3);text-align:center;}
.modal-title{font-size:20px;font-weight:800;color:var(--ink);}
.modal-sub{font-size:13px;color:var(--muted);margin:6px 0 18px;}
.diff-options{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;margin-bottom:20px;}
.diff-chip{border:1px solid #ecdcc9;background:#fffaf4;color:var(--muted);border-radius:999px;
  padding:9px 14px;font-size:14px;font-weight:600;cursor:pointer;transition:all .15s;letter-spacing:1px;}
.diff-chip.on{background:var(--purple);color:#fff;border-color:var(--purple);}
.diff-chip.all{background:#fffaf4;}
.diff-chip.all.on{background:var(--orange);border-color:var(--orange);}
.modal-start{width:100%;}
.modal-start:disabled{background:var(--muted);cursor:not-allowed;opacity:.7;}
.modal-count{font-size:13px;color:var(--purple);font-weight:700;margin:0 0 14px;}
.modal-back{display:block;text-align:center;margin-top:16px;color:var(--muted);font-size:14px;text-decoration:none;font-weight:500;}
.modal-back:hover{color:var(--orange);}

/* admin */
.admin{flex:1;overflow:visible;}
.card-form{background:#fff;border-radius:18px;padding:18px;box-shadow:0 10px 24px rgba(120,70,30,.12);display:flex;flex-direction:column;gap:4px;transition:flex-basis .28s ease,max-width .28s ease,opacity .2s ease,padding .2s ease;}
.card-form label{font-size:13px;color:var(--muted);font-weight:600;margin-top:10px;display:flex;justify-content:space-between;align-items:center;}
.card-form .req{color:#e0573e;font-size:11px;font-weight:700;}
.card-form textarea,.card-form input[type=text]{
  border:1px solid #ecdcc9;border-radius:12px;padding:12px;font-size:15px;font-family:inherit;resize:none;background:#fffaf4;
  line-height:1.5;white-space:pre-wrap;word-break:break-word;min-height:56px;max-height:340px;overflow-y:auto;}
.card-form input[type=file]{font-size:13px;margin-top:2px;}

/* 出处：二级联动 + 多条目 */
.source-list{display:flex;flex-wrap:wrap;gap:6px;margin:4px 0 2px;}
.source-chip{display:inline-flex;align-items:center;gap:6px;background:#e7e0f7;color:#6d4aa6;border-radius:999px;padding:4px 10px;font-size:13px;}
.source-chip button{border:none;background:none;color:#6d4aa6;cursor:pointer;font-size:15px;line-height:1;padding:0;}
.source-add{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin-top:2px;}
.src-select,.src-other{border:1px solid #ecdcc9;border-radius:10px;padding:8px 10px;font-size:14px;font-family:inherit;background:#fffaf4;}
.src-select:disabled{background:#f1ece4;color:#b3a797;cursor:not-allowed;opacity:.85;}
.src-other{flex:1;min-width:150px;}

.img-preview{margin-top:6px;}
.img-preview img{max-width:120px;border-radius:10px;border:1px solid #ecdcc9;}

/* star selector */
.star-widget{display:flex;gap:6px;margin-top:4px;}
.star-widget button{background:none;border:none;cursor:pointer;font-size:26px;line-height:1;padding:0;color:#d9c2a8;transition:color .15s;}
.star-widget button.on{color:var(--orange);}

/* 列表「难度」列的可点击星星 */
.diff-stars{display:inline-flex;gap:1px;align-items:center;}
.diff-stars button{background:none;border:none;cursor:pointer;font-size:15px;line-height:1;padding:0 1px;color:#d9c2a8;transition:color .15s;}
.diff-stars button.on{color:var(--orange);}
.diff-stars button:hover{color:#f3a35d;}

.form-actions{display:flex;gap:10px;margin-top:14px;}
.btn-sm{padding:8px 14px;font-size:13px;flex:none;}

.list-tools{display:flex;flex-wrap:wrap;align-items:center;gap:10px;margin:18px 4px 8px;}

/* 录入卡收起/展开图标按钮（位于操作行最右侧） */
.panel-toggle{
  margin-left:auto;display:inline-flex;align-items:center;justify-content:center;
  width:38px;height:34px;padding:0;border-radius:10px;
  border:1px solid #ecdcc9;background:#fffaf4;color:var(--muted);cursor:pointer;
  transition:color .15s,border-color .15s,background .15s;
}
.panel-toggle:hover{color:var(--purple);border-color:var(--purple);}
.panel-toggle.is-open{background:var(--orange);border-color:var(--orange);color:#fff;}
.panel-toggle svg{width:18px;height:18px;display:block;}

/* 录入卡默认收起：折叠其 flex 宽度而非移除，左栏(list-panel)即可响应式占满释放出的空间 */
body.form-collapsed .card-form{
  flex:0 0 0 !important;
  width:0;min-width:0;max-width:0;
  padding:0;border:0;margin:0;
  overflow:hidden;opacity:0;pointer-events:none;
}

/* 上下结构（<1100px，非并排）收起时直接隐藏，避免顶部残留巨大留空 */
@media (max-width:1099.98px){
  body.form-collapsed .card-form{display:none;}
}

.table-scroll{overflow-x:auto;-webkit-overflow-scrolling:touch;border-radius:14px;box-shadow:0 8px 20px rgba(120,70,30,.1);border:1px solid #ede3f7;}
.data-table{min-width:1180px;width:100%;border-collapse:separate;border-spacing:0;table-layout:fixed;background:#fff;font-size:13px;overflow:visible;}
.data-table th{background:#e7e0f7;color:var(--purple);text-align:left;padding:11px 10px;font-size:12px;font-weight:800;white-space:nowrap;letter-spacing:.5px;}
.data-table td{padding:11px 10px;border-top:1px solid #f3e7da;vertical-align:top;max-width:none;white-space:pre-wrap;word-break:break-word;}
.data-table tbody tr{height:48px;}
.data-table tbody tr.pad-row td{color:transparent;border-top:1px solid #f3e7da;}
.data-table tbody tr.pad-row:hover td{background:transparent;}
.data-table tr:hover td{background:#f9f6ff;}
.data-table td:first-child{font-weight:600;}
.data-table .thumb{max-width:60px;max-height:60px;border-radius:8px;display:block;}
.del-btn{border:none;background:#ffdede;color:#d64545;border-radius:8px;padding:6px 10px;font-size:12px;cursor:pointer;white-space:nowrap;}
.edit-btn{border:none;background:#e7e0f7;color:#6d4aa6;border-radius:8px;padding:6px 10px;font-size:12px;cursor:pointer;white-space:nowrap;}
.edit-btn:active{background:#d8cdf0;}

/* admin 宽屏自适应（不再限制为移动端窄列） */
.app--wide{max-width:900px;}
@media (min-width:768px){
  .app--wide .card-form{padding:24px;}
  .app--wide .data-table{min-width:1180px;}
  .app--wide .table-scroll{overflow-x:auto;}
}

/* admin 宽屏：列表在左、新建表单在右（MacBook Air 等约 ≥1100px 视口触发） */
@media (min-width:1100px){
  .app--wide{max-width:1440px;}
  .admin{display:flex;flex-direction:row;align-items:flex-start;gap:28px;}
  .card-form{order:2;flex:0 0 clamp(440px,42%,600px);margin-top:18px;align-self:flex-start;position:sticky;top:18px;max-height:calc(100vh - 36px);overflow-y:auto;}
  .list-panel{order:1;flex:1 1 auto;min-width:0;}
}

/* 列宽：题目 / 答案 / Quiz / Hint / 难度 / Note / 操作；Quiz 列加宽一倍 */
.data-table th,.data-table td{width:auto;}
.data-table th:nth-child(1),.data-table td:nth-child(1){width:180px;}   /* 题目（冻结左） */
.data-table th:nth-child(2),.data-table td:nth-child(2){width:220px;}   /* 答案 */
.data-table th:nth-child(3),.data-table td:nth-child(3){width:360px;}   /* Quiz（加宽一倍） */
.data-table th:nth-child(4),.data-table td:nth-child(4){width:220px;}   /* Hint */
.data-table th:nth-child(5),.data-table td:nth-child(5){width:120px;}   /* 难度 */
.data-table th:nth-child(6),.data-table td:nth-child(6){width:320px;}   /* Note（加宽一倍） */
.data-table th:nth-child(7),.data-table td:nth-child(7){width:180px;}   /* 操作（冻结右） */

/* 冻结列：左=题目，右=操作；中间 5 列随 .table-scroll 横向滚动 */
.data-table th:nth-child(1),.data-table td:nth-child(1){position:sticky;left:0;z-index:2;}
.data-table th:nth-child(7),.data-table td:nth-child(7){position:sticky;right:0;z-index:2;}
.data-table th:nth-child(1),.data-table th:nth-child(7){z-index:3;background:#e7e0f7;}
.data-table td:nth-child(1),.data-table td:nth-child(7){background:#fff;}
.data-table td:nth-child(1),.data-table th:nth-child(1){border-right:1px solid #ece9f3;}
.data-table td:nth-child(7),.data-table th:nth-child(7){border-left:1px solid #ece9f3;}

@media (max-width:767px){
  /* 卡片外观移到可滚动容器上；.data-table 解除 overflow，否则 sticky 失效 */
  .table-scroll{
    border:1px solid #ede3f7;border-radius:14px;
    box-shadow:0 8px 20px rgba(120,70,30,.1);
    overflow-x:auto;-webkit-overflow-scrolling:touch;
  }
  .data-table{border:none;border-radius:0;box-shadow:none;overflow:visible;min-width:1180px;}
}

.filter-bar{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin:16px 0 10px;}
.filter-label{font-size:13px;color:var(--muted);}
.filter-chip{border:1px solid #ecdcc9;background:#fffaf4;color:var(--muted);border-radius:999px;
  padding:6px 12px;font-size:13px;font-weight:600;cursor:pointer;letter-spacing:1px;}
.filter-chip.on{background:var(--purple);color:#fff;border-color:var(--purple);}

/* 列表顶部导航：左侧页码（靠左）、右侧关键词检索 */
.list-nav{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:14px 0 22px;flex-wrap:wrap;}
.pager{display:flex;align-items:center;justify-content:flex-start;gap:14px;margin-top:0;}
.page-info{font-size:13px;color:var(--muted);}
.pager .btn:disabled{opacity:.45;cursor:not-allowed;}

.search-box{display:flex;align-items:center;}
#searchInput{
  width:280px;max-width:60vw;padding:8px 14px;border-radius:999px;
  border:1px solid #ecdcc9;background:#fffaf4;color:var(--ink);font-size:14px;outline:none;
  transition:border-color .15s ease,box-shadow .15s ease;
}
#searchInput::placeholder{color:#b6a691;}
#searchInput:focus{border-color:var(--purple);box-shadow:0 0 0 3px rgba(109,74,166,.15);}

.empty-tip{text-align:center;color:var(--muted);font-size:14px;margin-top:14px;}

/* 题目编号与左右提示（卡片下方一行） */
.counter-row{display:flex;align-items:center;justify-content:space-between;width:100%;margin-top:2px;padding:0 2px;}
.hint-side{font-size:12px;color:var(--muted);white-space:nowrap;cursor:default;user-select:none;}
.counter{flex:none;text-align:center;min-width:54px;}

/* 主题切换按钮：当前选中项高亮为橙色 */
.btn.active{background:var(--orange);color:#fff;border-color:var(--orange);box-shadow:0 4px 12px rgba(239,125,59,.35);}

/* ===== admin 深色（固定启用，无切换） ===== */
body.admin-dark{
  --bg1:#241d18; --bg2:#140f0b;
  --ink:#f4ede2; --muted:#b6a692;
  --purple:#9b78e0; --orange:#ff9a52; --teal:#3fd0c0;
}
body.admin-dark .card-form{
  background:#2a221b;
  box-shadow:0 10px 24px rgba(0,0,0,.45);
}
body.admin-dark .card-form textarea,
body.admin-dark .card-form input[type=text]{
  background:#1f1812;
  border:1px solid #4a3a2c;
  color:var(--ink);
}
body.admin-dark .card-form textarea::placeholder,
body.admin-dark .card-form input[type=text]::placeholder{color:rgba(244,237,226,.45);}
body.admin-dark #searchInput{
  background:#1f1812;border:1px solid #4a3a2c;color:var(--ink);
}
body.admin-dark #searchInput::placeholder{color:rgba(244,237,226,.45);}
body.admin-dark #searchInput:focus{border-color:var(--purple);box-shadow:0 0 0 3px rgba(155,120,224,.22);}
body.admin-dark .panel-toggle{background:#1f1812;border-color:#4a3a2c;color:var(--muted);}
body.admin-dark .panel-toggle:hover{color:var(--purple);border-color:var(--purple);}
body.admin-dark .panel-toggle.is-open{background:var(--orange);border-color:var(--orange);color:#fff;}
body.admin-dark .src-select,
body.admin-dark .src-other{
  background:#1f1812;
  border:1px solid #4a3a2c;
  color:var(--ink);
}
body.admin-dark .src-select:disabled{background:#241c15;color:#8c7d6c;}
body.admin-dark .source-chip{background:rgba(155,120,224,.18);color:#c9b3f0;border:1px solid rgba(155,120,224,.4);}
body.admin-dark .source-chip button{color:#c9b3f0;}

/* —— 录入卡预览弹层（复刻 Quiz 页题卡）—— */
.pv-modal{position:fixed;inset:0;background:rgba(20,15,11,.62);backdrop-filter:blur(3px);
  display:flex;align-items:center;justify-content:center;padding:24px;z-index:60;}
.pv-modal[hidden]{display:none;}
.pv-card{width:100%;max-width:480px;display:flex;flex-direction:column;align-items:center;gap:14px;}
.pv-actions{display:flex;justify-content:center;}
.pv-close{width:46px;height:46px;border-radius:50%;border:none;cursor:pointer;
  background:rgba(255,255,255,.92);color:var(--purple);
  display:flex;align-items:center;justify-content:center;
  box-shadow:0 6px 18px rgba(0,0,0,.28);transition:transform .15s ease,background .15s ease;}
.pv-close:hover{transform:scale(1.06);background:#fff;}
.pv-close svg{width:20px;height:20px;}

/* 列表「操作」列：预览按钮（置于修改 / 删除之间） */
.pv-btn{border:none;background:#def2ef;color:#1f9c8b;border-radius:8px;padding:6px 10px;font-size:12px;cursor:pointer;white-space:nowrap;}
.pv-btn:active{background:#c9e8e3;}
body.admin-dark .pv-btn{background:#22413a;color:#5fd6c2;}
body.admin-dark .pv-btn:active{background:#2c5048;}

/* 预览卡片强制深色（与 Quiz 页深色题卡一致，且不提供切换） */
#previewModal .flip-front{background:linear-gradient(155deg,#3b3127,#2b231c);border-color:#5b4631;}
#previewModal .flip-back{background:linear-gradient(155deg,#3a2f24,#4a3829);border-color:var(--orange);}
#previewModal .face-text{color:var(--ink);}
#previewModal .front-hint,#previewModal .back-note{color:var(--muted);}
#previewModal .front-hint.revealed{color:var(--ink);}
body.admin-dark .data-table{
  background:#2a221b;
  border:1px solid rgba(255,255,255,.1);
  box-shadow:0 8px 20px rgba(0,0,0,.4);
}
body.admin-dark .data-table th{background:#3a2f24;color:var(--purple);}
body.admin-dark .data-table td{border-top:1px solid rgba(255,255,255,.08);}
body.admin-dark .data-table tbody tr.pad-row td{border-top:1px solid rgba(255,255,255,.08);}
body.admin-dark .data-table tr:hover td{background:#332a22;}
body.admin-dark .data-table tbody tr.pad-row:hover td{background:transparent;}
body.admin-dark .del-btn{background:rgba(214,69,69,.18);color:#ff9a9a;border:1px solid rgba(214,69,69,.4);}
body.admin-dark .edit-btn{background:rgba(155,120,224,.18);color:#c9b3f0;border:1px solid rgba(155,120,224,.4);}
body.admin-dark .edit-btn:active{background:rgba(155,120,224,.3);}
body.admin-dark .filter-chip{background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.14);color:var(--muted);}
body.admin-dark .filter-chip.on{background:var(--purple);color:#fff;border-color:var(--purple);}
body.admin-dark .btn-ghost{background:rgba(255,255,255,.08);color:var(--ink);border:1px solid rgba(255,255,255,.16);}
body.admin-dark .btn-ghost:hover{background:rgba(255,255,255,.14);}
/* 冻结列：深色背景，避免白底刺眼 */
body.admin-dark .table-scroll{border:1px solid rgba(255,255,255,.1);box-shadow:0 8px 20px rgba(0,0,0,.4);}
body.admin-dark .data-table th:nth-child(1),
body.admin-dark .data-table th:nth-child(7){background:#3a2f24;}
body.admin-dark .data-table td:nth-child(1),
body.admin-dark .data-table td:nth-child(7){background:#2a221b;}

/* ===== 深色主题（仅答题页 Friends 风格；admin 页不加 .theme-dark，故不受影响） ===== */
body.theme-dark{
  --bg1:#241d18; --bg2:#140f0b;
  --ink:#f4ede2; --muted:#b6a692;
  --purple:#9b78e0; --orange:#ff9a52; --teal:#3fd0c0;
}
body.theme-dark .flip-front{background:linear-gradient(155deg,#3b3127,#2b231c);border-color:#5b4631;}
body.theme-dark .flip-back{background:linear-gradient(155deg,#3a2f24,#4a3829);border-color:var(--orange);}
body.theme-dark .btn-ghost{background:rgba(255,255,255,.08);color:var(--ink);border:1px solid rgba(255,255,255,.16);}
body.theme-dark .link-btn{color:var(--ink);}
body.theme-dark .link-btn.active{color:var(--purple);}
body.theme-dark .toggle-sep{color:var(--muted);}
body.theme-dark .lang-btn{color:var(--ink);}
body.theme-dark .lang-btn.active{color:var(--purple);}
body.theme-dark .lang-sep{color:var(--muted);}
body.theme-dark .modal{background:rgba(0,0,0,.6);}
body.theme-dark .modal-card{background:#2a221b;box-shadow:0 20px 50px rgba(0,0,0,.5);}
body.theme-dark .diff-chip{background:rgba(255,255,255,.06);color:var(--muted);border-color:rgba(255,255,255,.16);}
body.theme-dark .diff-chip.on{background:var(--purple);color:#fff;border-color:var(--purple);}
body.theme-dark .diff-chip.all.on{background:var(--orange);border-color:var(--orange);}
body.theme-dark .front-hint{color:var(--muted);}
body.theme-dark .front-hint.revealed{color:var(--ink);}
body.theme-dark .back-note{color:var(--muted);}

/* ===== 首页（landing）：两卡入口 ===== */
.app--home{max-width:920px;}
.home{display:flex;flex-direction:column;align-items:center;gap:22px;padding:6px 4px 30px;}
.home-lead{font-size:16px;color:var(--muted);margin:2px 0;line-height:1.6;text-align:center;}
.home-cards{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px;width:100%;max-width:760px;}
.home-card{
  display:flex;flex-direction:column;align-items:center;text-align:center;gap:4px;
  background:linear-gradient(160deg,#ffffff,#fff6ee);
  border:2px solid #ffe2c4;border-radius:24px;padding:18px 20px 16px;
  text-decoration:none;color:var(--ink);cursor:pointer;
  box-shadow:0 14px 30px rgba(120,70,30,.16);
  transition:transform .18s ease,box-shadow .18s ease,border-color .18s ease;
}
.home-card:hover{transform:translateY(-6px);box-shadow:0 22px 46px rgba(120,70,30,.24);border-color:var(--orange);}
.home-card--line:hover{border-color:var(--purple);}
.hc-icon-wrap{
  width:62px;height:62px;border-radius:50%;display:flex;align-items:center;justify-content:center;
  background:rgba(239,125,59,.12);margin-bottom:4px;
}
.home-card--line .hc-icon-wrap{background:rgba(109,74,166,.12);}
.hc-icon{width:34px;height:34px;}
.home-card h2{font-size:20px;line-height:1.45;margin:4px 0 0;font-weight:800;}
.home-card p{font-size:14px;color:var(--muted);margin:2px 0 0;line-height:1.55;}
.home-card-cta{margin-top:8px;font-weight:700;font-size:14px;color:var(--purple);letter-spacing:.5px;}
.home-card--quiz .home-card-cta{color:var(--orange);}
.home-card:hover .home-card-cta{color:var(--orange);}
.home-card--line:hover .home-card-cta{color:var(--purple);}
@media (max-width:640px){
  .home-cards{grid-template-columns:1fr;max-width:420px;}
}

/* 首页深色（复用 .theme-dark 暗色变量） */
body.theme-dark .home-card{
  background:linear-gradient(160deg,#2b231c,#211a14);
  border-color:rgba(255,255,255,.12);
}
body.theme-dark .home-card:hover{border-color:var(--orange);}
body.theme-dark .home-card--line:hover{border-color:var(--purple);}
body.theme-dark .hc-icon-wrap{background:rgba(255,154,82,.18);}
body.theme-dark .home-card--line .hc-icon-wrap{background:rgba(155,120,224,.18);}