/* ==========================================================
   刷题站 · 设计系统
   ========================================================== */

:root {
  /* 底色与表面 —— 中性浅灰底 + 纯白卡片，参考企业后台 */
  --bg: #f4f6f9;
  --surface: #ffffff;
  --surface-2: #fafbfc;
  --surface-3: #f2f4f7;

  /* 文字 */
  --text: #1f2329;
  --text-2: #52596b;
  --muted: #8a91a0;
  --faint: #a8aeba;

  /* 描边 —— 用边框划结构，不靠阴影 */
  --border: #e9ebf0;
  --border-strong: #d9dee6;

  /* 主色 */
  --primary: #1668dc;
  --primary-600: #0f56ba;
  --primary-soft: #eaf2ff;
  --primary-line: #c3daff;

  /* 语义色 */
  --easy: #129a5f;
  --easy-soft: #e7f7ef;
  --easy-line: #b6e7d0;
  --medium: #c47b06;
  --medium-soft: #fff5e3;
  --medium-line: #f4dcaf;
  --hard: #d63a48;
  --hard-soft: #fdeeef;
  --hard-line: #f6c9cd;

  --ok: #129a5f;
  --ok-soft: #e7f7ef;
  --bad: #d63a48;
  --bad-soft: #fdeeef;

  /* 面试重要程度 —— 四档各占一个色相，避免和难度（绿/橙/红）撞色 */
  --imp-must: #b5266f;
  --imp-must-soft: #fdeaf3;
  --imp-must-line: #f7c6dd;
  --imp-key: #0d8a72;
  --imp-key-soft: #e6f7f2;
  --imp-key-line: #b6e6da;
  --imp-aware: #1668dc;
  --imp-aware-soft: #eaf2ff;
  --imp-aware-line: #c3daff;

  /* 圆角与阴影 —— 后台风格：小圆角、极轻阴影 */
  --r-xs: 4px;
  --r-sm: 6px;
  --r: 8px;
  --r-lg: 10px;
  --r-xl: 12px;

  --sh-1: 0 1px 2px rgba(20, 30, 50, .04);
  --sh-2: 0 2px 8px rgba(20, 30, 50, .07);
  --sh-3: 0 8px 26px rgba(20, 30, 50, .10);
  --sh-4: 0 20px 60px rgba(12, 18, 32, .22);

  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
          "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", sans-serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Consolas, "Cascadia Code", Menlo, monospace;

  --maxw: 1180px;
  --side-w: 208px;
  --top-h: 52px;
}

/* ---------- 基础重置 ---------- */
* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-600); }

button, input, select, textarea { font-family: inherit; font-size: inherit; color: inherit; }

h1, h2, h3, h4 { margin: 0; font-weight: 700; letter-spacing: -.01em; line-height: 1.35; }

::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #d3d8e6; border-radius: 99px; border: 3px solid transparent; background-clip: content-box; }
::-webkit-scrollbar-thumb:hover { background: #b9c0d4; background-clip: content-box; }

.hidden { display: none !important; }

/* ==========================================================
   封面页
   ========================================================== */
.cover-page {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: #0b1020;
}

/* 背景图层：图片 + 兜底渐变 */
.cover-bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  background-color: #0b1020;
  background-image:
    var(--cover-image, none),
    radial-gradient(1200px 700px at 12% 8%, #3a4fd6 0%, rgba(58, 79, 214, 0) 55%),
    radial-gradient(900px 600px at 88% 22%, #7b3fe4 0%, rgba(123, 63, 228, 0) 55%),
    radial-gradient(1000px 800px at 60% 100%, #12b5a4 0%, rgba(18, 181, 164, 0) 55%),
    linear-gradient(160deg, #111a3a 0%, #0a0f22 60%, #05080f 100%);
  background-size: cover, auto, auto, auto, cover;
  background-position: center, center, center, center, center;
  background-repeat: no-repeat;
  transform: scale(1.04);
  transition: transform 1.2s cubic-bezier(.2, .7, .2, 1), filter .3s ease;
}

.cover-bg.is-loaded { transform: scale(1); }

/* 遮罩层 */
.cover-veil {
  position: fixed;
  inset: 0;
  z-index: 1;
  background:
    linear-gradient(180deg, rgba(5, 9, 22, .62) 0%, rgba(5, 9, 22, .30) 32%, rgba(5, 9, 22, .78) 100%),
    radial-gradient(1100px 620px at 50% 26%, rgba(5, 9, 22, 0) 0%, rgba(5, 9, 22, .42) 100%);
  backdrop-filter: blur(var(--cover-blur, 0px)) saturate(1.08);
  -webkit-backdrop-filter: blur(var(--cover-blur, 0px)) saturate(1.08);
}

.cover-topbar {
  position: relative;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 22px 34px;
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 11px;
  color: #fff;
  font-weight: 700;
  letter-spacing: .02em;
}

.brand-mark {
  width: 34px; height: 34px;
  border-radius: 10px;
  display: grid; place-items: center;
  background: linear-gradient(140deg, #6e8bff, #4356e8 55%, #8b5cf6);
  box-shadow: 0 6px 18px rgba(67, 86, 232, .45);
  font-size: 17px;
}

.brand-sub { font-weight: 500; color: rgba(255, 255, 255, .5); font-size: 13px; letter-spacing: .06em; }

.cover-tools { display: flex; align-items: center; gap: 10px; }

.ghost-btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 15px;
  border-radius: 99px;
  border: 1px solid rgba(255, 255, 255, .22);
  background: rgba(255, 255, 255, .08);
  color: #fff;
  font-size: 13.5px;
  cursor: pointer;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: background .2s, border-color .2s, transform .15s;
}
.ghost-btn:hover { background: rgba(255, 255, 255, .17); border-color: rgba(255, 255, 255, .38); }
.ghost-btn:active { transform: translateY(1px); }

.cover-main {
  position: relative;
  z-index: 5;
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 30px 24px 60px;
}

.cover-card {
  position: relative;
  width: min(880px, 100%);
  padding: 54px 56px 46px;
  border-radius: var(--r-xl);
  /* 深色玻璃：背景图再亮也能保证白色文字可读 */
  background: linear-gradient(160deg, rgba(14, 20, 44, .58), rgba(8, 12, 28, .46));
  border: 1px solid rgba(255, 255, 255, .14);
  box-shadow: var(--sh-4);
  backdrop-filter: blur(16px) saturate(1.25);
  -webkit-backdrop-filter: blur(16px) saturate(1.25);
  color: #fff;
  text-align: center;
  animation: rise .8s cubic-bezier(.2, .8, .2, 1) both;
}

/* 背景图偏亮时再压一层暗色，保底可读性 */
.cover-card::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: radial-gradient(120% 90% at 50% 0%, rgba(5, 9, 22, .26), rgba(5, 9, 22, .48));
  pointer-events: none;
}

.cover-card > * { position: relative; z-index: 1; }

@keyframes rise {
  from { opacity: 0; transform: translateY(22px); }
  to { opacity: 1; transform: none; }
}

.cover-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 15px;
  border-radius: 99px;
  background: rgba(255, 255, 255, .12);
  border: 1px solid rgba(255, 255, 255, .18);
  font-size: 12.5px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, .86);
  margin-bottom: 24px;
}
.cover-eyebrow .dot { width: 6px; height: 6px; border-radius: 50%; background: #5eead4; box-shadow: 0 0 10px #5eead4; }

.cover-title {
  font-size: clamp(38px, 6.4vw, 66px);
  line-height: 1.06;
  letter-spacing: -.035em;
  font-weight: 800;
  margin-bottom: 8px;
  background: linear-gradient(180deg, #ffffff 22%, rgba(255, 255, 255, .72) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.cover-title-sub {
  font-size: clamp(17px, 2.3vw, 23px);
  font-weight: 600;
  color: rgba(255, 255, 255, .82);
  letter-spacing: .01em;
  margin-bottom: 20px;
}

.cover-desc {
  max-width: 560px;
  margin: 0 auto 34px;
  font-size: 15.5px;
  line-height: 1.85;
  color: rgba(255, 255, 255, .72);
}

/* 统计组 */
.stat-row {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 30px;
}

.stat {
  min-width: 96px;
  padding: 13px 18px;
  border-radius: var(--r);
  background: rgba(255, 255, 255, .08);
  border: 1px solid rgba(255, 255, 255, .13);
  text-align: center;
  transition: background .2s, transform .2s;
}
.stat:hover { background: rgba(255, 255, 255, .14); transform: translateY(-2px); }
.stat-num { font-size: 24px; font-weight: 800; letter-spacing: -.02em; line-height: 1.2; font-variant-numeric: tabular-nums; }
.stat-label { font-size: 12px; color: rgba(255, 255, 255, .6); margin-top: 2px; letter-spacing: .04em; }
.stat.easy .stat-num { color: #4ade9f; }
.stat.medium .stat-num { color: #ffc860; }
.stat.hard .stat-num { color: #ff8d99; }

/* 掌握度进度 */
.mastery-wrap { max-width: 460px; margin: 0 auto 34px; }
.mastery-head {
  display: flex; justify-content: space-between;
  font-size: 12.5px; color: rgba(255, 255, 255, .62);
  margin-bottom: 8px; letter-spacing: .04em;
}
.mastery-track {
  height: 8px; border-radius: 99px;
  background: rgba(255, 255, 255, .13);
  overflow: hidden;
}
.mastery-fill {
  height: 100%; width: 0;
  border-radius: 99px;
  background: linear-gradient(90deg, #6e8bff, #5eead4);
  box-shadow: 0 0 16px rgba(94, 234, 212, .5);
  transition: width .9s cubic-bezier(.2, .8, .2, 1);
}

/* 按钮 */
.cover-actions { display: flex; justify-content: center; flex-wrap: wrap; gap: 14px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 13px 28px;
  border-radius: 99px;
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: transform .16s, box-shadow .22s, background .22s, color .2s, border-color .2s;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px) scale(.995); }

.btn-primary {
  background: linear-gradient(135deg, #5b74ff, #4356e8 55%, #7c4dff);
  color: #fff;
  box-shadow: 0 10px 28px rgba(67, 86, 232, .45);
}
.btn-primary:hover { box-shadow: 0 14px 34px rgba(67, 86, 232, .58); transform: translateY(-1px); color: #fff; }

.btn-glass {
  background: rgba(255, 255, 255, .1);
  border-color: rgba(255, 255, 255, .24);
  color: #fff;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
.btn-glass:hover { background: rgba(255, 255, 255, .18); color: #fff; }

.btn-ink {
  background: var(--text);
  color: #fff;
}
.btn-ink:hover { background: #232a3a; color: #fff; }

.btn-line {
  background: var(--surface);
  border-color: var(--border-strong);
  color: var(--text-2);
  box-shadow: var(--sh-1);
}
.btn-line:hover { border-color: var(--primary-line); color: var(--primary); background: var(--primary-soft); }

.btn-danger {
  background: linear-gradient(135deg, #f2606b, #d93a48 60%, #b32b38);
  color: #fff;
  box-shadow: 0 10px 26px rgba(217, 58, 72, .38);
}
.btn-danger:hover { box-shadow: 0 14px 32px rgba(217, 58, 72, .5); transform: translateY(-1px); color: #fff; }

.btn-ghost-danger {
  background: var(--surface);
  border-color: var(--hard-line);
  color: var(--hard);
}
.btn-ghost-danger:hover { background: var(--hard-soft); border-color: var(--hard); color: var(--hard); }

.btn-sm { padding: 8px 16px; font-size: 13.5px; }
.btn-xs { padding: 6px 12px; font-size: 12.5px; border-radius: 9px; }
.btn-block { width: 100%; }
.btn[disabled] { opacity: .45; cursor: not-allowed; box-shadow: none; transform: none; }

/* 题库板块入口 */
.board-strip {
  position: relative;
  z-index: 5;
  width: min(980px, 100%);
  margin: 0 auto;
  padding: 0 24px 34px;
}

.board-strip-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 14px;
  flex-wrap: wrap;
}
.bs-title {
  font-size: 15px;
  font-weight: 700;
  color: #fff;
  letter-spacing: .02em;
}
.bs-sub { font-size: 12.5px; color: rgba(255, 255, 255, .5); }

.board-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 14px;
}

.board-card {
  position: relative;
  display: block;
  padding: 17px 18px 16px;
  border-radius: var(--r-lg);
  background: rgba(255, 255, 255, .08);
  border: 1px solid rgba(255, 255, 255, .16);
  backdrop-filter: blur(16px) saturate(1.2);
  -webkit-backdrop-filter: blur(16px) saturate(1.2);
  color: #fff;
  text-decoration: none;
  overflow: hidden;
  transition: transform .22s cubic-bezier(.2, .8, .2, 1), background .22s, border-color .22s, box-shadow .22s;
}
.board-card::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(110, 139, 255, .22), transparent 58%);
  opacity: 0;
  transition: opacity .22s;
  pointer-events: none;
}
.board-card:hover {
  transform: translateY(-3px);
  background: rgba(255, 255, 255, .14);
  border-color: rgba(255, 255, 255, .34);
  box-shadow: 0 18px 42px rgba(4, 8, 22, .42);
  color: #fff;
}
.board-card:hover::after { opacity: 1; }

.bc-name {
  position: relative;
  z-index: 1;
  font-size: 16.5px;
  font-weight: 800;
  letter-spacing: -.01em;
  margin-bottom: 3px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.bc-desc {
  position: relative;
  z-index: 1;
  font-size: 12.5px;
  color: rgba(255, 255, 255, .62);
  line-height: 1.6;
  margin-bottom: 13px;
  min-height: 20px;
}
.bc-foot {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12.5px;
  color: rgba(255, 255, 255, .78);
}
.bc-foot .n { font-weight: 800; font-size: 15px; font-variant-numeric: tabular-nums; }
.bc-dots { display: inline-flex; gap: 4px; margin-left: auto; }
.bc-dots i {
  width: 7px; height: 7px; border-radius: 50%; display: block;
}
.bc-dots i.e { background: #4ade9f; }
.bc-dots i.m { background: #ffc860; }
.bc-dots i.h { background: #ff8d99; }

.bc-bar {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 3px;
  background: linear-gradient(90deg, #6e8bff, #5eead4);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .4s cubic-bezier(.2, .8, .2, 1);
}
.board-card:hover .bc-bar { transform: scaleX(1); }

@media (max-width: 720px) {
  .board-strip { padding: 0 14px 28px; }
  .board-grid { grid-template-columns: 1fr; gap: 11px; }
}

.cover-foot {
  position: relative;
  z-index: 5;
  padding: 18px 34px 26px;
  display: flex;
  justify-content: center;
  gap: 22px;
  flex-wrap: wrap;
  font-size: 12.5px;
  color: rgba(255, 255, 255, .42);
  letter-spacing: .04em;
}
.cover-foot kbd {
  font-family: var(--mono);
  font-size: 11px;
  padding: 2px 6px;
  border-radius: 5px;
  background: rgba(255, 255, 255, .12);
  border: 1px solid rgba(255, 255, 255, .18);
  color: rgba(255, 255, 255, .8);
}

/* ==========================================================
   应用内页（刷题 / 管理）
   ========================================================== */
.app-page {
  min-height: 100vh;
  background: var(--bg);
}

.app-page.has-bg::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  background-image: var(--app-image, none);
  background-size: cover;
  background-position: center;
  opacity: var(--bg-opacity, .10);
  filter: blur(var(--bg-blur, 3px)) saturate(1.15);
  pointer-events: none;
}

.app-shell { position: relative; z-index: 1; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 0 26px;
  height: 62px;
  background: rgba(255, 255, 255, .84);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(16px) saturate(1.4);
  -webkit-backdrop-filter: blur(16px) saturate(1.4);
}

.topbar .brand { color: var(--text); gap: 10px; }
.topbar .brand-mark { width: 30px; height: 30px; border-radius: 9px; font-size: 15px; }
.topbar .brand-sub { color: var(--muted); font-size: 12.5px; }

.topbar-spacer { flex: 1; }

.nav-tabs { display: flex; gap: 4px; background: var(--surface-3); padding: 4px; border-radius: 11px; }
.nav-tab {
  padding: 7px 16px;
  border-radius: 8px;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--muted);
  cursor: pointer;
  border: none;
  background: transparent;
  transition: all .18s;
}
.nav-tab:hover { color: var(--text-2); }
.nav-tab.active { background: var(--surface); color: var(--primary); box-shadow: var(--sh-1); }

.topbar-stat {
  display: flex; align-items: center; gap: 8px;
  font-size: 13px; color: var(--muted);
  padding-left: 18px; border-left: 1px solid var(--border);
}
.topbar-stat b { color: var(--text); font-variant-numeric: tabular-nums; font-weight: 700; }

/* 布局 */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 26px 26px 90px; }

.layout {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 26px;
  align-items: start;
}

/* ---------- 侧栏 ---------- */
.side {
  position: sticky;
  top: 84px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r);
  box-shadow: var(--sh-1);
  overflow: hidden;
}

.panel-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 13px 16px;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
  font-weight: 700;
  color: var(--text-2);
  letter-spacing: .02em;
  background: var(--surface-2);
}
.panel-body { padding: 14px 16px 16px; }
.panel-head .micro { font-weight: 500; font-size: 12px; color: var(--faint); }

/* 筛选条目 */
.filter-group + .filter-group { margin-top: 18px; }
.filter-label {
  font-size: 12px; font-weight: 700; color: var(--faint);
  letter-spacing: .09em; text-transform: uppercase;
  margin-bottom: 9px;
}

.chip-list { display: flex; flex-wrap: wrap; gap: 7px; }

.chip {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 6px 12px;
  border-radius: 99px;
  border: 1px solid var(--border-strong);
  background: var(--surface);
  font-size: 13px;
  color: var(--text-2);
  cursor: pointer;
  transition: all .16s;
  user-select: none;
}
.chip:hover { border-color: var(--primary-line); color: var(--primary); background: var(--primary-soft); }
.chip.active { background: var(--primary); border-color: var(--primary); color: #fff; font-weight: 600; box-shadow: 0 4px 12px rgba(63, 86, 224, .3); }
.chip .cnt { font-size: 11px; opacity: .7; font-variant-numeric: tabular-nums; }
.chip.diff-easy.active { background: var(--easy); border-color: var(--easy); box-shadow: 0 4px 12px rgba(15, 157, 99, .3); }
.chip.diff-medium.active { background: var(--medium); border-color: var(--medium); box-shadow: 0 4px 12px rgba(209, 131, 0, .3); }
.chip.diff-hard.active { background: var(--hard); border-color: var(--hard); box-shadow: 0 4px 12px rgba(217, 58, 72, .3); }

/* 面试重要程度：四档各用一个色相，和难度（绿/橙/红）区分开 */
.chip.imp-must { color: var(--imp-must); border-color: var(--imp-must-line); }
.chip.imp-must.active { background: var(--imp-must); border-color: var(--imp-must); color: #fff; box-shadow: 0 4px 12px rgba(181, 38, 111, .3); }
.chip.imp-key { color: var(--imp-key); border-color: var(--imp-key-line); }
.chip.imp-key.active { background: var(--imp-key); border-color: var(--imp-key); color: #fff; box-shadow: 0 4px 12px rgba(13, 138, 114, .3); }
.chip.imp-aware { color: var(--imp-aware); border-color: var(--imp-aware-line); }
.chip.imp-aware.active { background: var(--imp-aware); border-color: var(--imp-aware); color: #fff; box-shadow: 0 4px 12px rgba(63, 86, 224, .3); }
.chip.imp-normal { color: var(--muted); }
.chip.imp-normal.active { background: var(--muted); border-color: var(--muted); color: #fff; box-shadow: none; }

.sel {
  width: 100%;
  padding: 9px 12px;
  border-radius: var(--r-sm);
  border: 1px solid var(--border-strong);
  background: var(--surface);
  font-size: 13.5px;
  color: var(--text);
  cursor: pointer;
  outline: none;
  transition: border-color .18s, box-shadow .18s;
}
.sel:focus { border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-soft); }

/* 进度环 / 小统计 */
.mini-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 9px; }
.mini-stat {
  padding: 11px 12px;
  border-radius: var(--r-sm);
  background: var(--surface-3);
  text-align: center;
}
.mini-stat b { display: block; font-size: 19px; font-weight: 800; letter-spacing: -.02em; font-variant-numeric: tabular-nums; }
.mini-stat span { font-size: 11.5px; color: var(--muted); }

/* ---------- 主区 ---------- */
.main-col { min-width: 0; display: flex; flex-direction: column; gap: 18px; }

.bar {
  display: flex; align-items: center; gap: 14px; flex-wrap: wrap;
  padding: 14px 18px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r);
  box-shadow: var(--sh-1);
}
.bar-info { display: flex; align-items: center; gap: 10px; font-size: 13.5px; color: var(--muted); }
.bar-info b { color: var(--text); font-variant-numeric: tabular-nums; }
.bar-spacer { flex: 1; }

.progress-line {
  height: 6px; border-radius: 99px; background: var(--surface-3);
  overflow: hidden; flex: 1; min-width: 120px; max-width: 260px;
}
.progress-line > i {
  display: block; height: 100%; width: 0;
  background: linear-gradient(90deg, #6e8bff, #4356e8);
  border-radius: 99px;
  transition: width .45s cubic-bezier(.2, .8, .2, 1);
}

/* 题目卡 */
.q-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: var(--sh-2);
  overflow: hidden;
  animation: rise .45s cubic-bezier(.2, .8, .2, 1) both;
}

.q-head {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  padding: 18px 26px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, var(--surface-2), var(--surface));
}

.q-index {
  font-family: var(--mono);
  font-size: 12.5px;
  font-weight: 700;
  color: var(--primary);
  background: var(--primary-soft);
  border: 1px solid var(--primary-line);
  padding: 4px 10px;
  border-radius: 8px;
  font-variant-numeric: tabular-nums;
}

.q-head-spacer { flex: 1; }

.tag {
  display: inline-flex; align-items: center;
  padding: 4px 10px;
  border-radius: 99px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .02em;
  background: var(--surface-3);
  color: var(--text-2);
  border: 1px solid var(--border);
}
.tag.d-easy { background: var(--easy-soft); color: var(--easy); border-color: var(--easy-line); }
.tag.d-medium { background: var(--medium-soft); color: var(--medium); border-color: var(--medium-line); }
.tag.d-hard { background: var(--hard-soft); color: var(--hard); border-color: var(--hard-line); }
.tag.type { background: var(--primary-soft); color: var(--primary); border-color: var(--primary-line); }
.tag.board { background: #f3ecff; color: #6d3fc4; border-color: #ddc9ff; }

/* 面试重要程度标签（卡片头部） */
.tag.imp-must { background: var(--imp-must-soft); color: var(--imp-must); border-color: var(--imp-must-line); font-weight: 700; }
.tag.imp-key { background: var(--imp-key-soft); color: var(--imp-key); border-color: var(--imp-key-line); font-weight: 700; }
.tag.imp-aware { background: var(--imp-aware-soft); color: var(--imp-aware); border-color: var(--imp-aware-line); }

.icon-btn {
  width: 32px; height: 32px;
  display: grid; place-items: center;
  border-radius: 9px;
  border: 1px solid var(--border-strong);
  background: var(--surface);
  color: var(--muted);
  cursor: pointer;
  font-size: 15px;
  transition: all .16s;
  line-height: 1;
}
.icon-btn:hover { color: var(--primary); border-color: var(--primary-line); background: var(--primary-soft); }
.icon-btn.on { color: #e0a800; border-color: #f2d58a; background: #fff9e8; }

.q-body { padding: 26px 26px 8px; }

.q-stem {
  font-size: 17.5px;
  font-weight: 600;
  line-height: 1.82;
  color: var(--text);
  letter-spacing: .002em;
  white-space: pre-wrap;
  word-break: break-word;
}

/* 标签 + 来源：来源靠右、弱化，不再和主标签抢注意力 */
.q-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 15px;
  padding-top: 13px;
  border-top: 1px dashed var(--border);
}
.q-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.q-tags .tag { font-weight: 500; font-size: 11.5px; background: transparent; color: var(--muted); }
.q-source {
  margin-left: auto;
  font-size: 12px;
  color: var(--faint);
  white-space: nowrap;
}

/* 选项 */
.options { display: flex; flex-direction: column; gap: 15px; padding: 20px 26px 6px; }
/* 选项 + 它的解析绑成一组，组内紧凑、组间留白，视觉上不会糊成一片 */
.opt-group { display: flex; flex-direction: column; gap: 7px; }

.opt {
  display: flex;
  align-items: flex-start;
  gap: 13px;
  width: 100%;
  text-align: left;
  padding: 15px 17px;
  border-radius: var(--r);
  border: 1.5px solid var(--border);
  background: var(--surface);
  cursor: pointer;
  transition: border-color .16s, background .16s, transform .16s, box-shadow .16s;
  font-size: 15px;
  line-height: 1.7;
  color: var(--text-2);
}
.opt:hover:not(.locked) { border-color: var(--primary-line); background: var(--primary-soft); transform: translateX(2px); }
.opt-key {
  flex: none;
  width: 26px; height: 26px;
  border-radius: 8px;
  display: grid; place-items: center;
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 700;
  background: var(--surface-3);
  color: var(--text-2);
  border: 1px solid var(--border);
  margin-top: 1px;
  transition: all .16s;
}
.opt-text { flex: 1; min-width: 0; white-space: pre-wrap; word-break: break-word; }

.opt.picked { border-color: var(--primary); background: var(--primary-soft); }
.opt.picked .opt-key { background: var(--primary); border-color: var(--primary); color: #fff; }

.opt.locked { cursor: default; }

.opt.correct { border-color: var(--easy); background: var(--easy-soft); }
.opt.correct .opt-key { background: var(--easy); border-color: var(--easy); color: #fff; }

.opt.wrong { border-color: var(--hard); background: var(--hard-soft); }
.opt.wrong .opt-key { background: var(--hard); border-color: var(--hard); color: #fff; }

.opt-mark { flex: none; font-size: 13px; font-weight: 700; margin-top: 2px; }
.opt-mark.c { color: var(--easy); }
.opt-mark.w { color: var(--hard); }

.opt-why {
  margin-left: 39px;
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
  padding: 8px 13px;
  border-radius: var(--r-xs);
  background: var(--surface-2);
  border-left: 2px solid var(--border-strong);
}

/* 简答题输入 */
.text-answer { padding: 20px 26px 6px; }
.textarea {
  width: 100%;
  min-height: 110px;
  padding: 14px 16px;
  border-radius: var(--r);
  border: 1.5px solid var(--border-strong);
  background: var(--surface-2);
  font-size: 14.5px;
  line-height: 1.75;
  resize: vertical;
  outline: none;
  transition: border-color .18s, box-shadow .18s, background .18s;
}
.textarea:focus { border-color: var(--primary); background: var(--surface); box-shadow: 0 0 0 3px var(--primary-soft); }

/* 操作条 */
.actions {
  display: flex; align-items: center; gap: 12px; flex-wrap: wrap;
  padding: 20px 26px 24px;
  border-top: 1px solid var(--border);
  margin-top: 16px;
  background: var(--surface-2);
}
.actions-spacer { flex: 1; }

.hint-key { font-size: 12px; color: var(--faint); display: flex; align-items: center; gap: 6px; }
.hint-key kbd {
  font-family: var(--mono); font-size: 11px;
  padding: 2px 6px; border-radius: 5px;
  background: var(--surface);
  border: 1px solid var(--border-strong);
  color: var(--text-2);
  box-shadow: 0 1px 0 var(--border-strong);
}

/* 判定横幅 */
.verdict {
  display: flex; align-items: center; gap: 12px;
  margin: 0 26px;
  padding: 14px 18px;
  border-radius: var(--r);
  font-size: 15px;
  font-weight: 700;
  animation: rise .3s ease both;
}
.verdict.ok { background: var(--ok-soft); color: var(--ok); border: 1px solid var(--easy-line); }
.verdict.bad { background: var(--bad-soft); color: var(--bad); border: 1px solid var(--hard-line); }
.verdict.info { background: var(--primary-soft); color: var(--primary); border: 1px solid var(--primary-line); }
.verdict-detail { font-weight: 500; font-size: 13.5px; opacity: .85; }

/* ---------- 讲解 ---------- */
.explain { padding: 4px 26px 26px; }

.explain-block {
  border-radius: var(--r);
  border: 1px solid var(--border);
  overflow: hidden;
  margin-top: 16px;
  background: var(--surface);
}

.explain-head {
  display: flex; align-items: center; gap: 10px;
  width: 100%;
  padding: 15px 18px;
  background: var(--surface-2);
  border: none;
  cursor: pointer;
  text-align: left;
  transition: background .18s;
}
.explain-head:hover { background: var(--surface-3); }

.explain-badge {
  flex: none;
  width: 30px; height: 30px;
  border-radius: 9px;
  display: grid; place-items: center;
  font-size: 15px;
}
.plain-block .explain-badge { background: #fff2d6; }
.pro-block .explain-badge { background: var(--primary-soft); }

.explain-title { font-size: 14.5px; font-weight: 700; color: var(--text); }
.explain-title small { display: block; font-weight: 500; font-size: 12px; color: var(--muted); letter-spacing: .02em; }

.explain-head-spacer { flex: 1; }

.explain-caret {
  font-size: 12px; color: var(--muted);
  transition: transform .25s cubic-bezier(.2, .8, .2, 1);
}
.explain-block.open .explain-caret { transform: rotate(180deg); }

.explain-body {
  display: none;
  padding: 20px 22px 22px;
  font-size: 15px;
  line-height: 1.95;
  color: var(--text-2);
  border-top: 1px solid var(--border);
  word-break: break-word;
}
.explain-block.open .explain-body { display: block; animation: rise .3s ease both; }

.plain-block { border-color: #f2dcae; }
.plain-block .explain-body { background: linear-gradient(180deg, #fffdf7, #ffffff); }

.pro-block { border-color: var(--primary-line); }
.pro-block .explain-body { background: linear-gradient(180deg, #fafbff, #ffffff); }

/* ---- 讲解正文的结构化排版 ----
   原文是 \n\n 分段 + · 列表 + 编号小标题，
   渲染成真正的 p / ul / 小标题，读起来才不糊成一片。 */
.explain-body p { margin: 0 0 13px; }
.explain-body p:last-child { margin-bottom: 0; }

/* 编号行做小标题：左侧细线 + 稍重字色，形成阅读节奏 */
.explain-body p.exp-sub {
  margin: 17px 0 11px;
  padding-left: 11px;
  border-left: 3px solid var(--border-strong);
  font-weight: 600;
  color: var(--text);
  line-height: 1.8;
}
.explain-body p.exp-sub:first-child { margin-top: 2px; }
.plain-block .explain-body p.exp-sub { border-left-color: #e8c87f; }
.pro-block .explain-body p.exp-sub { border-left-color: var(--primary-line); }

/* 项目符号列表：自定义圆点，行距比正文略紧，视觉上是一"块" */
.explain-body ul {
  list-style: none;
  margin: 4px 0 14px;
  padding: 0;
}
.explain-body ul li {
  position: relative;
  padding-left: 18px;
  margin: 7px 0;
  line-height: 1.85;
}
.explain-body ul li::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 0.75em;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--border-strong);
}
.plain-block .explain-body ul li::before { background: #e8c87f; }
.pro-block .explain-body ul li::before { background: var(--primary-line); }

.explain-body b, .explain-body strong { color: var(--text); font-weight: 700; }
.explain-body code {
  font-family: var(--mono);
  font-size: 13px;
  padding: 2px 6px;
  border-radius: 5px;
  background: var(--surface-3);
  border: 1px solid var(--border);
  color: #c0276b;
}
.pro-block .explain-body code { color: var(--primary-600); }

.pro-locked {
  margin-top: 16px;
  padding: 15px 18px;
  border-radius: var(--r);
  border: 1px dashed var(--border-strong);
  background: var(--surface-2);
  display: flex; align-items: center; gap: 12px;
  font-size: 13.5px;
  color: var(--muted);
}

/* 代码块 */
.code-wrap { margin-top: 16px; border-radius: var(--r); overflow: hidden; border: 1px solid #23305a; }
.code-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 8px 14px;
  background: #1b2444;
  color: #8fa3d9;
  font-size: 12px;
  font-family: var(--mono);
  letter-spacing: .06em;
  border-bottom: 1px solid #2a3660;
}
.code-body {
  margin: 0;
  padding: 16px 18px;
  background: #131a33;
  color: #d5deff;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.75;
  overflow-x: auto;
  white-space: pre;
  tab-size: 2;
}

/* 空状态 */
.empty {
  padding: 80px 30px;
  text-align: center;
  color: var(--muted);
}
.empty-icon {
  width: 66px; height: 66px;
  margin: 0 auto 20px;
  border-radius: 20px;
  display: grid; place-items: center;
  background: var(--surface-3);
  font-size: 28px;
}
.empty h3 { font-size: 17px; color: var(--text-2); margin-bottom: 8px; }
.empty p { font-size: 14px; margin: 0 0 22px; }

/* ==========================================================
   管理页
   ========================================================== */
.sec-head {
  display: flex; align-items: flex-end; justify-content: space-between;
  gap: 16px; flex-wrap: wrap; margin-bottom: 20px;
}
.sec-title { font-size: 22px; font-weight: 800; letter-spacing: -.02em; }
.sec-desc { font-size: 13.5px; color: var(--muted); margin-top: 5px; }

.search-box {
  position: relative;
  flex: 1;
  min-width: 200px;
  max-width: 340px;
}
.search-box input {
  width: 100%;
  padding: 10px 14px 10px 38px;
  border-radius: 99px;
  border: 1px solid var(--border-strong);
  background: var(--surface);
  font-size: 14px;
  outline: none;
  transition: border-color .18s, box-shadow .18s;
}
.search-box input:focus { border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-soft); }
.search-box .si {
  position: absolute; left: 14px; top: 50%; transform: translateY(-50%);
  color: var(--faint); font-size: 14px; pointer-events: none;
}

.q-rows { display: flex; flex-direction: column; gap: 10px; }

.q-row {
  display: flex; align-items: center; gap: 14px;
  padding: 15px 18px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r);
  box-shadow: var(--sh-1);
  transition: border-color .18s, box-shadow .18s, transform .18s, background .18s;
}
.q-row:hover { border-color: var(--primary-line); box-shadow: var(--sh-2); transform: translateY(-1px); }
.q-row.selected { border-color: var(--primary); background: var(--primary-soft); box-shadow: 0 0 0 3px rgba(63, 86, 224, .10); }
.q-row.trashed { opacity: .78; }
.q-row.trashed:hover { opacity: 1; }

.q-row-idx {
  flex: none;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--faint);
  width: 34px;
  text-align: right;
  font-variant-numeric: tabular-nums;
}
.q-row-main { flex: 1; min-width: 0; }
.q-row-title {
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.q-row-meta { display: flex; gap: 7px; margin-top: 6px; flex-wrap: wrap; align-items: center; }
.q-row-ops { display: flex; gap: 7px; flex: none; }
.q-row-idx.wide { width: 26px; }
.q-row-sub { font-size: 12px; color: var(--faint); margin-top: 4px; }

/* 复选框 */
.cbx {
  flex: none;
  width: 18px; height: 18px;
  appearance: none;
  -webkit-appearance: none;
  border: 1.5px solid var(--border-strong);
  border-radius: 5px;
  background: var(--surface);
  cursor: pointer;
  position: relative;
  transition: all .16s;
  margin: 0;
}
.cbx:hover { border-color: var(--primary); }
.cbx:checked { background: var(--primary); border-color: var(--primary); }
.cbx:checked::after {
  content: "";
  position: absolute;
  left: 5px; top: 1.5px;
  width: 5px; height: 9px;
  border: solid #fff;
  border-width: 0 2px 2px 0;
  transform: rotate(43deg);
}
.cbx:indeterminate { background: var(--primary); border-color: var(--primary); }
.cbx:indeterminate::after {
  content: "";
  position: absolute;
  left: 3px; top: 7px;
  width: 8px; height: 2px;
  background: #fff;
  border-radius: 2px;
  border: none;
  transform: none;
}

/* 批量操作条 */
.bulk-bar {
  position: sticky;
  top: 74px;
  z-index: 30;
  display: flex; align-items: center; gap: 12px; flex-wrap: wrap;
  padding: 12px 18px;
  margin-bottom: 14px;
  border-radius: var(--r);
  background: linear-gradient(135deg, #2b3352, #1c2340);
  color: #fff;
  box-shadow: var(--sh-3);
  animation: rise .28s cubic-bezier(.2, .8, .2, 1) both;
}
.bulk-bar .cnt { font-size: 14px; font-weight: 700; }
.bulk-bar .cnt b { font-size: 17px; font-variant-numeric: tabular-nums; }
.bulk-bar .sp { flex: 1; }
.bulk-bar .sel {
  width: auto; min-width: 108px;
  background: rgba(255, 255, 255, .10);
  border-color: rgba(255, 255, 255, .22);
  color: #fff;
  font-size: 13px;
}
.bulk-bar .sel option { color: var(--text); background: #fff; }
.bulk-bar .btn-line {
  background: rgba(255, 255, 255, .10);
  border-color: rgba(255, 255, 255, .24);
  color: #fff;
  box-shadow: none;
}
.bulk-bar .btn-line:hover { background: rgba(255, 255, 255, .2); border-color: rgba(255, 255, 255, .4); color: #fff; }
.bulk-bar .btn-danger { box-shadow: none; }
.bulk-sep { width: 1px; height: 22px; background: rgba(255, 255, 255, .18); }

/* 列表头部（全选行） */
.list-head {
  display: flex; align-items: center; gap: 14px;
  padding: 10px 18px;
  font-size: 12.5px;
  color: var(--muted);
  border: 1px dashed var(--border-strong);
  border-radius: var(--r);
  background: var(--surface-2);
  margin-bottom: 10px;
}
.list-head label { display: flex; align-items: center; gap: 8px; cursor: pointer; font-weight: 600; color: var(--text-2); }

/* 分页 */
.pager {
  display: flex; align-items: center; justify-content: center; gap: 7px;
  margin-top: 20px; flex-wrap: wrap;
}
.pager button {
  min-width: 34px; height: 34px;
  padding: 0 10px;
  border-radius: 9px;
  border: 1px solid var(--border-strong);
  background: var(--surface);
  color: var(--text-2);
  font-size: 13.5px;
  font-weight: 600;
  cursor: pointer;
  font-variant-numeric: tabular-nums;
  transition: all .16s;
}
.pager button:hover:not(:disabled) { border-color: var(--primary-line); color: var(--primary); background: var(--primary-soft); }
.pager button.active { background: var(--primary); border-color: var(--primary); color: #fff; }
.pager button:disabled { opacity: .4; cursor: not-allowed; }
.pager .info { font-size: 13px; color: var(--muted); margin-right: 8px; }

/* 删除确认里的题目预览 */
.del-list { display: flex; flex-direction: column; gap: 8px; }
.del-item {
  display: flex; gap: 10px; align-items: flex-start;
  padding: 10px 12px;
  border-radius: var(--r-sm);
  background: var(--surface-3);
  font-size: 13.5px;
  line-height: 1.6;
  border-left: 3px solid var(--border-strong);
}
.del-item .n { color: var(--faint); font-family: var(--mono); font-size: 12px; flex: none; padding-top: 2px; }
.del-item .t { min-width: 0; }
.del-item .t b { display: block; font-weight: 600; color: var(--text); }
.del-item .t span { color: var(--muted); font-size: 12.5px; }

/* 表单校验错误 */
.input.err, .input-area.err, .sel.err {
  border-color: var(--hard) !important;
  background: var(--hard-soft) !important;
  box-shadow: 0 0 0 3px rgba(217, 58, 72, .12) !important;
  animation: shake .38s cubic-bezier(.36, .07, .19, .97);
}
@keyframes shake {
  10%, 90% { transform: translateX(-2px); }
  20%, 80% { transform: translateX(3px); }
  30%, 50%, 70% { transform: translateX(-5px); }
  40%, 60% { transform: translateX(5px); }
}
.field.err label { color: var(--hard); }
.field-err-msg {
  font-size: 12.5px; color: var(--hard); font-weight: 600;
  display: flex; align-items: center; gap: 5px;
}

/* 标签快捷区 */
.tag-picker {
  display: flex; flex-wrap: wrap; gap: 6px;
  margin-top: 8px;
  max-height: 88px;
  overflow-y: auto;
}
.tag-quick {
  padding: 3px 10px;
  border-radius: 99px;
  border: 1px dashed var(--border-strong);
  background: var(--surface-2);
  font-size: 12px;
  color: var(--muted);
  cursor: pointer;
  transition: all .16s;
}
.tag-quick:hover { border-style: solid; border-color: var(--primary-line); color: var(--primary); background: var(--primary-soft); }
.tag-quick.used { opacity: .38; pointer-events: none; }

/* 选项编辑器：数量控制 */
.opt-tools {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  margin-top: 12px;
}
.opt-count { font-size: 12.5px; color: var(--faint); }

/* 草稿提示条 */
.draft-bar {
  display: flex; align-items: center; gap: 12px; flex-wrap: wrap;
  padding: 13px 17px;
  margin-bottom: 18px;
  border-radius: var(--r);
  background: var(--medium-soft);
  border: 1px solid var(--medium-line);
  font-size: 13.5px;
  color: var(--text-2);
}
.draft-bar .ni { font-size: 16px; flex: none; }
.draft-bar .sp { flex: 1; }

/* 回收站空态 */
.trash-note {
  display: flex; align-items: center; gap: 10px;
  padding: 13px 17px;
  border-radius: var(--r);
  background: var(--surface-2);
  border: 1px dashed var(--border-strong);
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 18px;
}

/* 表单 */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.field { display: flex; flex-direction: column; gap: 7px; }
.field.full { grid-column: 1 / -1; }
.field label { font-size: 13px; font-weight: 700; color: var(--text-2); }
.field label .req { color: var(--hard); margin-left: 3px; }
.field .tip { font-size: 12px; color: var(--faint); font-weight: 400; }

.input, .input-area {
  width: 100%;
  padding: 10px 13px;
  border-radius: var(--r-sm);
  border: 1px solid var(--border-strong);
  background: var(--surface);
  font-size: 14px;
  outline: none;
  transition: border-color .18s, box-shadow .18s;
}
.input:focus, .input-area:focus { border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-soft); }
.input-area { min-height: 96px; resize: vertical; line-height: 1.75; font-size: 14px; }
.input-area.tall { min-height: 140px; }
.input-area.mono { font-family: var(--mono); font-size: 12.5px; line-height: 1.7; }

.form-actions {
  display: flex; gap: 12px; align-items: center;
  padding-top: 20px; margin-top: 22px;
  border-top: 1px solid var(--border);
  flex-wrap: wrap;
}

.opt-editor { display: flex; flex-direction: column; gap: 10px; }
.opt-editor-row { display: flex; gap: 10px; align-items: flex-start; }
.opt-editor-key {
  flex: none;
  width: 40px; height: 40px;
  display: grid; place-items: center;
  border-radius: var(--r-sm);
  background: var(--surface-3);
  border: 1px solid var(--border-strong);
  font-family: var(--mono);
  font-weight: 700;
  font-size: 14px;
  color: var(--text-2);
  cursor: pointer;
  transition: all .16s;
  user-select: none;
}
.opt-editor-key:hover { border-color: var(--primary-line); color: var(--primary); }
.opt-editor-key.correct { background: var(--easy); border-color: var(--easy); color: #fff; box-shadow: 0 4px 12px rgba(15, 157, 99, .3); }
.opt-editor-col { flex: 1; display: flex; flex-direction: column; gap: 7px; min-width: 0; }

/* Toast */
.toast-wrap {
  position: fixed;
  right: 24px; bottom: 24px;
  z-index: 999;
  display: flex; flex-direction: column; gap: 10px;
  pointer-events: none;
}
.toast {
  display: flex; align-items: center; gap: 10px;
  padding: 13px 18px;
  border-radius: var(--r);
  background: #1b2233;
  color: #fff;
  font-size: 14px;
  box-shadow: var(--sh-3);
  animation: toastIn .3s cubic-bezier(.2, .8, .2, 1) both;
  max-width: 340px;
}
.toast.ok { background: linear-gradient(135deg, #0f9d63, #0b7a4d); }
.toast.bad { background: linear-gradient(135deg, #d93a48, #b32b38); }
.toast.out { animation: toastOut .25s ease both; }

/* 带操作按钮的 toast（撤销） */
.toast.act {
  pointer-events: auto;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-right: 12px;
}
.toast-btn {
  flex: none;
  padding: 6px 13px;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, .32);
  background: rgba(255, 255, 255, .14);
  color: #fff;
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  transition: background .18s, border-color .18s;
  white-space: nowrap;
}
.toast-btn:hover { background: rgba(255, 255, 255, .28); border-color: rgba(255, 255, 255, .5); }

@keyframes toastIn { from { opacity: 0; transform: translateX(24px) scale(.96); } to { opacity: 1; transform: none; } }
@keyframes toastOut { to { opacity: 0; transform: translateX(24px) scale(.96); } }

/* 模态 */
.modal-mask {
  position: fixed; inset: 0; z-index: 200;
  background: rgba(14, 19, 35, .5);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: grid; place-items: center;
  padding: 24px;
  animation: fade .2s ease both;
}
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }

.modal {
  width: min(560px, 100%);
  max-height: 86vh;
  overflow: auto;
  background: var(--surface);
  border-radius: var(--r-lg);
  box-shadow: var(--sh-4);
  animation: rise .3s cubic-bezier(.2, .8, .2, 1) both;
}
.modal-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
}
.modal-head h3 { font-size: 17px; }
.modal-body { padding: 22px 24px; }
.modal-foot {
  display: flex; justify-content: flex-end; gap: 11px;
  padding: 16px 24px 20px;
  border-top: 1px solid var(--border);
  background: var(--surface-2);
}

/* 背景图选择器 */
.bg-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(104px, 1fr));
  gap: 11px;
}

.bg-pick {
  position: relative;
  aspect-ratio: 16 / 10;
  border: 2px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  cursor: pointer;
  background: var(--surface-3);
  transition: border-color .18s, transform .18s, box-shadow .18s;
}
.bg-pick:hover { border-color: var(--primary-line); transform: translateY(-2px); box-shadow: var(--sh-2); }
.bg-pick.active { border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-soft); }

.bg-pick .ph {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
}
.bg-pick .nm {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  padding: 14px 8px 5px;
  font-size: 11.5px;
  font-weight: 600;
  color: #fff;
  background: linear-gradient(transparent, rgba(4, 8, 20, .78));
  letter-spacing: .02em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.bg-pick .ck {
  position: absolute;
  top: 6px; right: 6px;
  width: 20px; height: 20px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  display: none;
  place-items: center;
  font-size: 11px;
  box-shadow: 0 2px 8px rgba(63, 86, 224, .5);
}
.bg-pick.active .ck { display: grid; }

.bg-pick.tile {
  display: grid;
  place-items: center;
  gap: 4px;
  border-style: dashed;
  border-color: var(--border-strong);
  color: var(--muted);
  font-size: 11.5px;
  font-weight: 600;
  text-align: center;
  padding: 6px;
}
.bg-pick.tile:hover { color: var(--primary); border-color: var(--primary-line); background: var(--primary-soft); }
.bg-pick.tile .ic { font-size: 17px; line-height: 1; }
.bg-pick.none-tile .ph {
  background-image: repeating-linear-gradient(135deg, #eef1f8 0 8px, #e2e7f3 8px 16px);
}

.bg-slot { margin-top: 6px; }
.bg-slot + .bg-slot { margin-top: 24px; }
.bg-slot-head {
  display: flex; align-items: center; gap: 9px;
  margin-bottom: 10px;
}
.bg-slot-head .lab { font-size: 13px; font-weight: 700; color: var(--text-2); }
.bg-slot-head .hint { font-size: 12px; color: var(--faint); }

/* 提示条 */
.notice {
  display: flex; gap: 12px; align-items: flex-start;
  padding: 14px 17px;
  border-radius: var(--r);
  background: var(--primary-soft);
  border: 1px solid var(--primary-line);
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--text-2);
  margin-bottom: 20px;
}
.notice .ni { flex: none; font-size: 16px; }
.notice b { color: var(--primary-600); }
.notice code {
  font-family: var(--mono); font-size: 12.5px;
  padding: 1px 5px; border-radius: 4px;
  background: #fff; border: 1px solid var(--primary-line);
  color: var(--primary-600);
}

/* 响应式 */
@media (max-width: 1024px) {
  .layout { grid-template-columns: 1fr; }
  .side { position: static; }
  .side .panel-body { padding: 12px 14px 14px; }
  .mini-stats { grid-template-columns: repeat(4, 1fr); }
}

@media (max-width: 900px) {
  .bulk-bar { top: 68px; }
  .bulk-bar .cnt b { font-size: 15px; }
}

@media (max-width: 720px) {
  .cover-card { padding: 38px 24px 34px; }
  .q-row { flex-wrap: wrap; gap: 10px; }
  .q-row-main { flex: 1 1 100%; order: 3; }
  .q-row-ops { order: 4; width: 100%; justify-content: flex-end; }
  .bulk-bar { gap: 8px; padding: 11px 13px; }
  .bulk-bar .btn { padding: 6px 11px; font-size: 12.5px; }
  .bulk-sep { display: none; }
  .list-head { padding: 9px 13px; }
  .cover-topbar { padding: 16px 18px; }
  .ghost-btn span { display: none; }
  .ghost-btn { padding: 8px 11px; }
  .wrap { padding: 18px 14px 70px; }
  .topbar { padding: 0 14px; gap: 10px; height: 58px; }
  .topbar .brand-sub { display: none; }
  .topbar-stat { display: none; }
  .nav-tab { padding: 7px 12px; font-size: 13px; }
  .q-head, .q-body, .options, .actions, .explain { padding-left: 18px; padding-right: 18px; }
  .verdict { margin: 0 18px; }
  .q-stem { font-size: 16.5px; }
  .form-grid { grid-template-columns: 1fr; }
  .mini-stats { grid-template-columns: 1fr 1fr; }
  .modal-foot { flex-direction: column-reverse; }
  .modal-foot .btn { width: 100%; }
}