/* ===== CDA L1 备考系统 · 浅蓝主题 ===== */
:root {
  --c-primary: #2f93ec;
  --c-primary-2: #5fb4f7;
  --c-success: #2bb673;
  --c-danger: #e0524f;
  --c-warn: #e0a23c;
  --c-bg: #f5fbff;
  --c-surface: #ffffff;
  --c-surface-2: #eaf4ff;
  --c-line: #d6e9fb;
  --c-text: #1f2d3d;
  --c-text-2: #69809a;
  --radius: 14px;
  --shadow: 0 8px 28px rgba(47, 147, 236, .12);
}
* { 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(--c-bg); color: var(--c-text);
  overflow-x: hidden; line-height: 1.6;
  -webkit-text-size-adjust: 100%;
}
.hidden, [hidden] { display: none !important; }

/* ===== 顶栏 ===== */
#topbar {
  position: sticky; top: 0; z-index: 30;
  display: flex; align-items: center; gap: 12px;
  height: 56px; padding: 0 14px;
  background: linear-gradient(90deg, var(--c-primary), var(--c-primary-2));
  color: #fff; box-shadow: 0 2px 10px rgba(0,0,0,.08);
}
#topbar .brand { font-weight: 800; font-size: 17px; letter-spacing: .5px; }
#railToggle { display: none; background: rgba(255,255,255,.2); border: none; color: #fff; font-size: 20px; width: 40px; height: 40px; border-radius: 10px; cursor: pointer; }
#subjbar { display: flex; align-items: center; gap: 8px; margin-left: 8px; }
#subjbar .subj-label { font-size: 13px; opacity: .9; }
#subjbar .subj-select { min-height: 36px; border-radius: 8px; border: none; padding: 0 10px; font-size: 14px; color: var(--c-text); }
#userBox { margin-left: auto; display: flex; align-items: center; gap: 8px; }
#userBox .hi { font-weight: 700; font-size: 14px; }
#userBox .btn.ghost { color: #fff; border-color: rgba(255,255,255,.55); background: rgba(255,255,255,.14); }
#userBox .btn.ghost:hover { background: rgba(255,255,255,.26); }

/* ===== 布局 ===== */
#app { display: flex; align-items: flex-start; min-height: calc(100vh - 56px); }
#sidebar {
  width: 232px; flex: 0 0 232px;
  background: var(--c-surface); border-right: 1px solid var(--c-line);
  position: sticky; top: 56px;
  max-height: calc(100vh - 56px);
  overflow-y: auto;
  padding: 12px 10px;
}
.side-brand { font-weight: 800; color: var(--c-primary); padding: 8px 12px 12px; font-size: 15px; }
#main { flex: 1; min-width: 0; padding: 18px; }
#view { max-width: 1080px; margin: 0 auto; }

/* ===== 侧栏导航 ===== */
.nav-item {
  display: flex; align-items: center; gap: 10px;
  padding: 11px 12px; border-radius: 10px; cursor: pointer;
  color: var(--c-text); font-size: 15px; margin-bottom: 4px; user-select: none;
}
.nav-item:hover { background: var(--c-surface-2); }
.nav-item.active { background: var(--c-surface-2); color: var(--c-primary); font-weight: 700; }
.ni-icon { font-size: 18px; }
.ni-name { flex: 1; }
.ni-caret { font-size: 12px; color: var(--c-text-2); transition: transform .2s; }
/* 两级可折叠侧栏：.has-sub 容器纵向堆叠，.nav-parent 为可点击表头，.nav-sub 为子项（skill 规定结构 .has-sub > .nav-parent + .nav-sub） */
.has-sub { display: block; padding: 0; margin-bottom: 4px; }
.has-sub > .nav-parent {
  display: flex; align-items: center; gap: 10px;
  padding: 11px 12px; border-radius: 10px; cursor: pointer;
  color: var(--c-text); font-size: 15px; user-select: none;
}
.has-sub > .nav-parent:hover { background: var(--c-surface-2); }
.has-sub.open > .nav-parent { color: var(--c-primary); font-weight: 700; }
.has-sub.open > .nav-parent .ni-caret { transform: rotate(180deg); }
.nav-badge { background: var(--c-danger); color: #fff; font-size: 11px; font-weight: 700; border-radius: 10px; padding: 1px 7px; min-width: 18px; text-align: center; }
.nav-sub { display: none; padding: 2px 0 4px 30px; }
.has-sub.open > .nav-parent + .nav-sub { display: block; }
.nav-sub-item { padding: 8px 10px; border-radius: 8px; font-size: 13px; color: var(--c-text-2); cursor: pointer; }
.nav-sub-item:hover { background: var(--c-surface-2); color: var(--c-primary); }

/* ===== 备考中心 ===== */
.login-banner {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  background: linear-gradient(90deg, #eaf4ff, #f5fbff);
  border: 1px solid var(--c-line); border-radius: var(--radius);
  padding: 14px 18px; margin-bottom: 16px;
}
.login-banner span { font-weight: 600; color: var(--c-text); }
.hero { background: linear-gradient(135deg, var(--c-primary), var(--c-primary-2)); color: #fff; border-radius: var(--radius); padding: 22px 22px; box-shadow: var(--shadow); margin-bottom: 18px; }
.hero-hi { font-size: 22px; font-weight: 800; }
.hero-date { opacity: .9; margin: 6px 0 14px; font-size: 14px; }
.mod-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 14px; }
.mod-card {
  position: relative; background: var(--c-surface); border: 1px solid var(--c-line); border-radius: var(--radius);
  padding: 20px 16px; cursor: pointer; text-align: center; transition: transform .15s, box-shadow .15s, border-color .15s; box-shadow: var(--shadow);
}
.mod-card:hover { transform: translateY(-3px); border-color: var(--c-primary); }
.mc-icon { font-size: 32px; }
.mc-name { font-weight: 700; margin-top: 8px; font-size: 15px; }
.mc-badge { position: absolute; top: 10px; right: 10px; background: var(--c-surface-2); color: var(--c-primary); font-size: 11px; font-weight: 700; border-radius: 10px; padding: 1px 8px; }

/* ===== 章节 / 试卷卡片 ===== */
.page-title { font-size: 20px; margin: 4px 0 16px; }
.rail-wide { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 14px; }
.chapter-card {
  text-align: left; background: var(--c-surface); border: 1px solid var(--c-line); border-radius: var(--radius);
  padding: 16px; cursor: pointer; box-shadow: var(--shadow); transition: transform .15s, border-color .15s;
}
.chapter-card:hover { transform: translateY(-3px); border-color: var(--c-primary); }
.cc-name { font-weight: 700; font-size: 15px; }
.cc-meta { color: var(--c-text-2); font-size: 13px; margin: 8px 0; }
.cc-progress { height: 7px; background: var(--c-surface-2); border-radius: 6px; overflow: hidden; }
.cc-progress i { display: block; height: 100%; background: linear-gradient(90deg, var(--c-primary), var(--c-primary-2)); }
.cc-cta { margin-top: 10px; color: var(--c-primary); font-weight: 700; font-size: 14px; }
.paper-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 14px; }
.paper-card { text-align: left; background: var(--c-surface); border: 1px solid var(--c-line); border-radius: var(--radius); padding: 16px; cursor: pointer; box-shadow: var(--shadow); transition: transform .15s, border-color .15s; }
.paper-card:hover { transform: translateY(-3px); border-color: var(--c-primary); }
.pc-name { font-weight: 700; font-size: 15px; }
.pc-meta { color: var(--c-text-2); font-size: 13px; margin: 8px 0; }
.pc-cta { color: var(--c-primary); font-weight: 700; font-size: 14px; }

/* ===== 答题卡 ===== */
.q-card { background: var(--c-surface); border: 1px solid var(--c-line); border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow); }
.q-stem { font-size: 16px; font-weight: 600; margin-bottom: 14px; line-height: 1.8; }
.q-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 12px; }
.q-type { background: var(--c-surface-2); color: var(--c-primary); font-size: 12px; font-weight: 700; padding: 2px 10px; border-radius: 8px; }
.q-idx { color: var(--c-text-2); font-size: 13px; }
.q-body { display: flex; flex-direction: column; gap: 10px; }
.opt {
  display: flex; align-items: flex-start; gap: 12px; text-align: left; width: 100%;
  background: var(--c-surface); border: 1px solid var(--c-line); border-radius: 12px;
  padding: 14px 16px; cursor: pointer; font-size: 15px; transition: border-color .15s, background .15s;
}
.opt:hover { border-color: var(--c-primary); }
.opt.sel { border-color: var(--c-primary); background: var(--c-surface-2); }
.opt.correct { border-color: var(--c-success); background: #e8f8f0; }
.opt.wrong { border-color: var(--c-danger); background: #fdecec; }
.opt-label { flex: 0 0 26px; width: 26px; height: 26px; border-radius: 50%; background: var(--c-surface-2); color: var(--c-primary); display: grid; place-items: center; font-weight: 700; font-size: 14px; }
.opt.correct .opt-label { background: var(--c-success); color: #fff; }
.opt.wrong .opt-label { background: var(--c-danger); color: #fff; }
.opt-text { flex: 1; }
.q-actions { margin-top: 16px; }
.q-fav { margin-top: 12px; }
.fav-btn { background: none; border: 1px solid var(--c-line); border-radius: 10px; padding: 8px 14px; cursor: pointer; font-size: 14px; color: var(--c-text-2); }
.fav-btn:hover { border-color: var(--c-warn); color: var(--c-warn); }

/* 解析（渐进披露） */
.reveal { margin-top: 14px; background: var(--c-surface-2); border-radius: 12px; padding: 14px 16px; display: none; }
.reveal.show { display: block; }
.rv-correct { font-weight: 700; color: var(--c-success); margin-bottom: 6px; }
.rv-analysis { font-size: 14px; color: var(--c-text); }
.rv-analysis b { color: var(--c-primary); }

/* ===== 按钮 ===== */
.btn { border: none; border-radius: 12px; padding: 12px 20px; font-size: 15px; font-weight: 700; cursor: pointer; background: var(--c-surface-2); color: var(--c-text); transition: opacity .15s, transform .1s; }
.btn:active { transform: scale(.98); }
.btn.primary { background: linear-gradient(90deg, var(--c-primary), var(--c-primary-2)); color: #fff; }
.btn.danger { background: var(--c-danger); color: #fff; }
.btn.ghost { background: transparent; border: 1px solid var(--c-line); color: var(--c-text-2); }
.btn.tiny { padding: 8px 14px; font-size: 13px; min-height: 36px; }
.btn.block { display: block; width: 100%; }

/* ===== 考试模式 ===== */
.exambar { display: flex; align-items: center; justify-content: space-between; background: var(--c-surface); border: 1px solid var(--c-line); border-radius: 12px; padding: 10px 16px; margin-bottom: 14px; box-shadow: var(--shadow); position: sticky; top: 56px; z-index: 10; }
.exam-timer-wrap { font-size: 15px; color: var(--c-text-2); }
.exam-timer { font-size: 22px; font-weight: 800; font-variant-numeric: tabular-nums; color: var(--c-primary); }
.exam-timer.warn { color: var(--c-danger); }
.exam-layout { display: flex; gap: 16px; align-items: flex-start; }
.exam-palette { flex: 0 0 110px; display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; position: sticky; top: 126px; max-height: calc(100vh - 140px); overflow-y: auto; align-self: flex-start; }
.pal-btn { width: 100%; aspect-ratio: 1; border: 1px solid var(--c-line); background: var(--c-surface); border-radius: 8px; cursor: pointer; font-size: 13px; color: var(--c-text-2); }
.pal-btn.answered { background: var(--c-surface-2); color: var(--c-primary); }
.pal-btn.current { background: var(--c-primary); color: #fff; border-color: var(--c-primary); }
.exam-main { flex: 1; min-width: 0; }
.exam-wait { color: var(--c-success); font-weight: 700; padding: 10px 0; }

/* ===== 成绩单 ===== */
.complete-page { display: grid; place-items: center; padding: 10px; }
.complete-card { background: var(--c-surface); border: 1px solid var(--c-line); border-radius: var(--radius); padding: 26px; text-align: center; box-shadow: var(--shadow); width: min(520px, 100%); }
.complete-card h2 { margin: 0 0 10px; }
.ring { position: relative; width: 140px; height: 140px; border-radius: 50%; background: conic-gradient(var(--c-primary) calc(var(--p) * 1%), #e3edf7 0); margin: 18px auto; display: grid; place-items: center; }
.ring::before { content: ''; position: absolute; width: 104px; height: 104px; border-radius: 50%; background: var(--c-surface); }
.ring span { position: relative; font-size: 30px; font-weight: 800; color: var(--c-primary); }
.ring span small { font-size: 18px; font-weight: 500; }
.complete-stat { color: var(--c-text-2); margin-bottom: 10px; font-size: 14px; }
.complete-level { display: flex; align-items: center; justify-content: center; gap: 10px; font-size: 18px; font-weight: 700; margin-bottom: 16px; }
.complete-level.pass { color: var(--c-success); }
.complete-level.fail { color: var(--c-danger); }
.level-badge { display: inline-block; width: 38px; height: 38px; line-height: 38px; border-radius: 50%; font-weight: 900; font-size: 20px; color: #fff; text-align: center; }
.complete-level.pass .level-badge { background: var(--c-success); }
.complete-level.fail .level-badge { background: var(--c-danger); }
.weak-title { font-weight: 700; text-align: left; margin: 6px 0; }
.weak-list { text-align: left; color: var(--c-text-2); font-size: 14px; padding-left: 20px; margin: 0 0 8px; }
.weak-list li { margin: 4px 0; }
.action-group { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; margin-top: 16px; }

/* ===== 知识卡（3D 翻转） ===== */
.flashcard-page { max-width: 760px; margin: 0 auto; }
.kb-curpos { font-weight: 700; margin-bottom: 10px; color: var(--c-text-2); }
.flashcard { perspective: 1200px; }
.flashcard-inner {
  display: grid; grid-template: 1fr / 1fr;
  width: 100%; min-height: 280px;
  transform-style: preserve-3d;
  transition: transform .5s, min-height .35s ease;
  cursor: pointer;
}
.flashcard-inner.flipped { transform: rotateY(180deg); }
.flashcard-face {
  grid-row: 1; grid-column: 1;
  backface-visibility: hidden; -webkit-backface-visibility: hidden;
  border-radius: 16px; padding: 24px;
  background: var(--c-surface); border: 1px solid var(--c-line);
  box-shadow: var(--shadow);
  display: flex; flex-direction: column; justify-content: center;
  overflow: hidden;
}
.fc-front { align-items: center; text-align: center; }
.fc-title { font-size: 20px; font-weight: 800; color: var(--c-primary); }
.fc-hint { color: var(--c-text-2); margin-top: 14px; font-size: 14px; }
.fc-back {
  transform: rotateY(180deg);
  overflow-y: auto; overflow-x: hidden;
  justify-content: flex-start;
  max-height: 70vh;
}
.article-body { line-height: 1.85; font-size: 15px; }
.article-body table { border-collapse: collapse; margin: 12px 0; width: 100%; }
.article-body th, .article-body td { border: 1px solid var(--c-line); padding: 8px 10px; text-align: left; font-size: 14px; }
.article-body th { background: var(--c-surface-2); font-weight: 700; }
.article-body h2 { font-size: 18px; font-weight: 800; color: var(--c-primary); margin: 14px 0 10px; }
.article-body h3 { font-size: 16px; font-weight: 700; margin: 12px 0 8px; }
.article-body ul, .article-body ol { margin: 8px 0 12px 24px; }
.article-body li { margin: 4px 0; }
.article-body blockquote { border-left: 4px solid var(--c-primary); padding: 8px 14px; margin: 12px 0; background: var(--c-surface-2); border-radius: 6px; color: var(--c-text-2); }
.article-body strong { color: var(--c-primary); font-weight: 700; }
.article-body p { margin: 8px 0; }
.article-body .kb-code { background: var(--c-surface-2); border: 1px solid var(--c-line); border-radius: 8px; padding: 12px 14px; margin: 12px 0; overflow: auto; font-size: 13px; line-height: 1.6; }
.article-body .kb-code code { background: none; padding: 0; border-radius: 0; color: var(--c-text); white-space: pre; }
.article-body .kb-inline { background: var(--c-surface-2); border: 1px solid var(--c-line); padding: 1px 6px; border-radius: 4px; font-size: 13px; color: #c0392b; }

/* 知识卡彩色标注 */
.article-body mark.hl {
  background: linear-gradient(180deg, transparent 50%, #ffe066 50%);
  padding: 0 2px;
  color: inherit;
  border-radius: 2px;
}
.article-body .ktag {
  display: inline-block;
  background: #eef6ff;
  color: #2f93ec;
  border: 1px solid #c8e3fb;
  border-radius: 6px;
  padding: 1px 8px;
  font-size: 13px;
  font-weight: 600;
  margin: 2px 3px 2px 0;
  white-space: nowrap;
}
.article-body .ktag.red { background: #fff0ef; color: #e0524f; border-color: #f7d0cf; }
.article-body .ktag.green { background: #e8f8f0; color: #2bb673; border-color: #c8e9d6; }
.article-body .ktag.amber { background: #fff8e8; color: #e0a23c; border-color: #f5e3be; }
.article-body .ktag.purple { background: #f3eeff; color: #7c5cbf; border-color: #ddd0f5; }
.fc-actions { display: flex; gap: 12px; margin-top: 14px; }
.fc-btn { flex: 1; min-height: 46px; border-radius: 12px; border: none; font-weight: 700; font-size: 15px; cursor: pointer; }
.fc-btn.yes { background: var(--c-primary); color: #fff; }
.fc-btn.no { background: var(--c-surface-2); color: var(--c-text); }

/* 侧栏子项考试占比徽章 */
.nav-sub-item { display: flex; align-items: center; justify-content: space-between; }
.nav-pct { background: var(--c-primary); color: #fff; font-size: 11px; font-weight: 700; border-radius: 10px; padding: 1px 7px; margin-left: 6px; flex-shrink: 0; }
.fc-master { text-align: center; margin-top: 10px; }

/* ===== 错题 / 收藏 ===== */
.mb-head { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 10px; margin-bottom: 12px; }
.mb-title { font-size: 19px; font-weight: 800; }
.meta-tag { font-size: 12px; font-weight: 700; background: var(--c-surface-2); color: var(--c-primary); border-radius: 8px; padding: 2px 9px; margin-left: 6px; }
.seg { display: flex; gap: 8px; flex-wrap: wrap; }
.seg-btn { border: 1px solid var(--c-line); background: var(--c-surface); border-radius: 10px; padding: 7px 12px; font-size: 13px; cursor: pointer; color: var(--c-text-2); }
.seg-btn.on { background: var(--c-surface-2); color: var(--c-primary); font-weight: 700; border-color: var(--c-primary); }
.seg-btn.danger { color: var(--c-danger); border-color: var(--c-danger); }
.q-meta { color: var(--c-text-2); font-size: 13px; margin-bottom: 8px; }
.mb-actions { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 14px; }
.mb-page { font-size: 13px; color: var(--c-text-2); align-self: center; }

/* ===== 弹窗 / Toast / 状态 ===== */
.modal-mask { position: fixed; inset: 0; background: rgba(0,0,0,.4); display: grid; place-items: center; z-index: 50; padding: 20px; }
.modal { background: var(--c-surface); border-radius: 16px; padding: 22px; width: min(420px, 92vw); box-shadow: 0 20px 60px rgba(0,0,0,.25); }
.modal-title { margin: 0 0 6px; font-size: 18px; }
.modal-sub { margin: 0 0 14px; color: var(--c-text-2); font-size: 13px; }
.modal-input { width: 100%; min-height: 46px; padding: 0 14px; font-size: 16px; border: 1px solid var(--c-line); border-radius: 10px; }
.modal-actions { display: flex; gap: 10px; justify-content: flex-end; margin-top: 14px; }
.modal-err { color: var(--c-danger); font-size: 13px; min-height: 18px; margin: 8px 0 0; }
#toast { position: fixed; left: 50%; bottom: 40px; transform: translateX(-50%) translateY(20px); background: rgba(31,45,61,.92); color: #fff; padding: 10px 20px; border-radius: 24px; font-size: 14px; opacity: 0; pointer-events: none; transition: opacity .2s, transform .2s; z-index: 60; }
#toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }
.state-box { text-align: center; padding: 56px 20px; color: var(--c-text-2); }
.state-box .ico { font-size: 40px; display: block; margin-bottom: 12px; }
.state-box .msg { font-size: 15px; margin-bottom: 6px; color: var(--c-text); }
.state-box .sub { font-size: 13px; margin-bottom: 18px; max-width: 420px; margin-left: auto; margin-right: auto; word-break: break-all; }
.state-actions { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }
.loading-box { text-align: center; padding: 60px 20px; color: var(--c-text-2); }
pre { background: var(--c-surface-2); border-radius: 8px; padding: 10px; overflow: auto; }
code { background: var(--c-surface-2); padding: 1px 5px; border-radius: 4px; font-size: 13px; }

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  #railToggle { display: block; }
  #sidebar {
    position: fixed; top: 56px; left: 0; bottom: 0; z-index: 40;
    transform: translateX(-100%); transition: transform .25s; width: 240px; flex-basis: 240px;
    box-shadow: 0 0 30px rgba(0,0,0,.15);
    max-height: none; overflow-y: auto;
  }
  #sidebar.open { transform: translateX(0); }
  #railOverlay { position: fixed; inset: 56px 0 0 0; background: rgba(0,0,0,.35); z-index: 35; display: none; }
  #railOverlay.show { display: block; }
  .exambar { position: static; }
  .exam-layout { flex-direction: column; }
  .exam-palette { flex: none; grid-template-columns: repeat(8, 1fr); position: static; max-height: none; }
}
@media (max-width: 640px) {
  #main { padding: 12px; }
  .btn { width: 100%; }
  .exam-palette { grid-template-columns: repeat(6, 1fr); position: static; max-height: none; }
  .hero-hi { font-size: 19px; }
}