/* 理论（/lilun/）页面样式：颜色变量（深蓝主色，品牌红仅作点缀） */
.ll-main {
  --ll-primary: #1D4165;
  --ll-primary-hover: #122F4D;
  --ll-primary-soft: #EDF3F9;
  --ll-primary-line: #9FB5CA;
  --ll-ink: #202E3D;
  --ll-text: #3C4B5C;
  --ll-muted: #576578;
  --ll-line: #D5DEE7;
  --ll-line-soft: #E8EDF2;
  --ll-surface-soft: #F3F6F9;
  --ll-surface-hover: #EAF0F6;
  --ll-brand: #EC2139;
  --ll-success: #17613E;
  --ll-success-soft: #EDF7F0;
  --ll-success-line: #8CBDA0;
  --ll-error: #AC2634;
  --ll-error-soft: #FFF2F3;
  --ll-error-line: #D88C96;
  --ll-on-primary: #FFFFFF;
  --ll-on-status: #FFFFFF;
  --ll-surface: #FFFFFF;
  --ll-focus: #43556C;
  --ll-disabled-text: #59616C;
  --ll-disabled-bg: #E9ECF0;
}

/* 布局与组件：所有选择器以 .ll- 类为根，仅作用于理论频道内容区。 */
.ll-main {
  box-sizing: border-box;
  width: 960px;
  margin: 0 auto;
  padding: 4px 0 64px;
  color: var(--ll-text);
  background: var(--ll-surface);
  font-size: 16px;
  line-height: 1.8;
  font-variant-numeric: tabular-nums;
  -webkit-font-smoothing: antialiased;
}
.ll-main, .ll-main * {
  font-family: "Source Han Sans CN", "PingFang SC", "Microsoft YaHei", sans-serif;
  box-sizing: border-box;
}
.ll-main :where(h1, h2, h3, p, ul, ol, figure) { margin: 0; padding: 0; }
.ll-main :where(ul, ol) { list-style: none; }
.ll-main :where(a) {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--ll-ink);
  text-decoration: none;
  text-underline-offset: 5px;
}
.ll-main :where(a, button, select) {
  transition: background-color .16s ease, border-color .16s ease, color .16s ease;
}
.ll-main :where(a:hover) { color: var(--ll-ink); text-decoration: underline; }
.ll-main :where(a:focus-visible, button:focus-visible, select:focus-visible) {
  outline: 3px solid var(--ll-focus);
  outline-offset: 3px;
  border-radius: 4px;
}
.ll-main :where(button, select) { font-size: 16px; line-height: 1.8; }

/* 路径、页面标题、章节 */
.ll-crumb {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 48px;
  margin-bottom: 8px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ll-muted);
}
.ll-crumb a { flex: none; color: var(--ll-muted); }
.ll-crumb a:hover { color: var(--ll-ink); }
.ll-crumb i { font-style: normal; color: var(--ll-muted); }
.ll-crumb > span { min-width: 0; }
.ll-h1 {
  margin: 2px 0 10px;
  color: var(--ll-ink);
  font-size: 28px;
  font-weight: 700;
  line-height: 1.7;
  letter-spacing: -.4px;
}
.ll-lead { color: var(--ll-text); font-size: 16px; line-height: 1.8; }
.ll-lead a { text-decoration: underline; }
.ll-section { margin-top: 32px; }
.ll-section > h2 {
  position: relative;
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
  color: var(--ll-ink);
  font-size: 21px;
  line-height: 1.8;
  font-weight: 700;
}
.ll-section > h2::before {
  content: "";
  flex: none;
  width: 4px;
  height: 18px;
  border-radius: 1px;
  background: var(--ll-brand);
}
.ll-section > h2::after { content: ""; flex: 1; height: 1px; margin-left: 8px; background: var(--ll-line); }
.ll-group-title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 22px 0 10px;
  color: var(--ll-ink);
  font-size: 18px;
  line-height: 1.8;
  font-weight: 600;
}
.ll-count {
  flex: none;
  color: var(--ll-muted);
  font-size: 14px;
  line-height: 1.8;
  font-weight: 400;
  white-space: nowrap;
}
.ll-group-title .ll-count { padding: 1px 8px; border-radius: 4px; background: var(--ll-surface-soft); }
.ll-nav-back { margin-top: 28px; }
.ll-nav-back a { padding: 0 12px; border: 1px solid var(--ll-line); border-radius: 6px; }
.ll-nav-back a:hover { background: var(--ll-surface-hover); text-decoration: none; }

/* 操作：实心主按钮与浅底反馈使用不同的形态 */
.ll-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 7px 22px;
  border: 1px solid var(--ll-primary);
  border-radius: 6px;
  background: var(--ll-primary);
  color: var(--ll-on-primary);
  font-size: 16px;
  line-height: 1.8;
  font-weight: 600;
  text-align: center;
  white-space: nowrap;
  cursor: pointer;
}
.ll-btn:hover { border-color: var(--ll-primary-hover); background: var(--ll-primary-hover); color: var(--ll-on-primary); text-decoration: none; }
.ll-btn:active { transform: translateY(1px); }
.ll-btn:disabled { border-color: var(--ll-line); background: var(--ll-disabled-bg); color: var(--ll-disabled-text); cursor: default; }
.ll-btn-plain { border-color: var(--ll-line); background: var(--ll-surface); color: var(--ll-ink); font-weight: 500; }
.ll-btn-plain:hover { border-color: var(--ll-primary-line); background: var(--ll-primary-soft); color: var(--ll-ink); }
.ll-btn-lg { min-height: 50px; padding: 8px 26px; font-size: 17px; }
.ll-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin-top: 18px; }

/* 首页：紧凑的引导区、整行车型入口 */
.ll-hero {
  padding: 22px 26px 24px;
  border: 1px solid var(--ll-line);
  border-top: 3px solid var(--ll-brand);
  border-radius: 8px;
  background: var(--ll-surface-soft);
}
.ll-hero h1 { margin-bottom: 8px; color: var(--ll-ink); font-size: 26px; line-height: 1.7; font-weight: 700; letter-spacing: -.4px; }
.ll-hero p { color: var(--ll-text); font-size: 16px; line-height: 1.8; }
.ll-cards { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; margin-top: 20px; }
.ll-card { min-width: 0; padding: 20px 22px; border: 1px solid var(--ll-line); border-radius: 8px; background: var(--ll-surface); }
.ll-card h2 { margin-bottom: 6px; color: var(--ll-ink); font-size: 21px; line-height: 1.8; font-weight: 700; }
.ll-card h2 a { min-height: 44px; }
.ll-card-desc { min-height: 58px; margin-bottom: 12px; color: var(--ll-muted); font-size: 16px; line-height: 1.8; }
.ll-driver-grid { display: grid; grid-template-columns: minmax(0, 1fr); gap: 0; }
.ll-driver-grid .ll-tile { border-width: 0 0 1px; border-color: var(--ll-line-soft); border-radius: 0; background: var(--ll-surface); }
.ll-driver-grid .ll-tile:last-child { border-bottom-color: transparent; }
.ll-driver-grid .ll-tile:hover { border-color: var(--ll-line); background: var(--ll-surface-soft); }
.ll-driver-grid .ll-tile a { font-size: 16px; font-weight: 600; white-space: nowrap; }
.ll-cards-4 .ll-card { display: grid; grid-template-columns: minmax(0, 1fr) auto; column-gap: 12px; align-items: center; padding: 20px; }
.ll-cards-4 .ll-card h2 { grid-column: 1; margin: 0; font-size: 18px; white-space: nowrap; }
.ll-cards-4 .ll-card .ll-count { grid-column: 1; font-size: 16px; }
.ll-cards-4 .ll-card > p:last-child { grid-column: 2; grid-row: 1 / span 2; }
.ll-cards-4 .ll-btn { padding-right: 16px; padding-left: 16px; }

/* 所有入口复用整块可点击区域；箭头仅作装饰 */
.ll-tile {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  min-width: 0;
  min-height: 52px;
  padding: 4px 32px 4px 14px;
  border: 1px solid var(--ll-line-soft);
  border-radius: 6px;
  background: var(--ll-surface-soft);
  transition: background-color .16s ease, border-color .16s ease;
}
.ll-tile a { flex: 1; min-width: 0; font-size: 16px; line-height: 1.8; }
.ll-tile a::after { content: ""; position: absolute; inset: 0; border-radius: inherit; }
.ll-tile::after {
  content: "";
  position: absolute;
  top: 50%;
  right: 15px;
  width: 6px;
  height: 6px;
  margin-top: -3px;
  border-top: 1.5px solid var(--ll-muted);
  border-right: 1.5px solid var(--ll-muted);
  transform: rotate(45deg);
  pointer-events: none;
}
.ll-tile:hover { border-color: var(--ll-primary-line); background: var(--ll-primary-soft); }
.ll-tile:hover a { color: var(--ll-ink); text-decoration: none; }
.ll-tile:focus-within { outline: 3px solid var(--ll-focus); outline-offset: 2px; }
.ll-tile a:focus-visible { outline: none; }
.ll-tile-col { display: grid; grid-template-rows: 44px 1fr; align-items: start; align-content: start; gap: 8px; min-height: 144px; padding: 16px 18px 18px; }
.ll-tile-col a { align-self: start; font-size: 18px; font-weight: 600; }
.ll-tile-col > span { color: var(--ll-muted); font-size: 16px; line-height: 1.8; }
.ll-tile-col::after { top: 36px; right: 19px; }
.ll-mode-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; }
.ll-mode-grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.ll-mode-grid-3 .ll-tile-col { min-height: 126px; }
.ll-cat-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px 12px; }
.ll-cat-grid-3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.ll-cat-group + .ll-cat-group { margin-top: 24px; padding-top: 4px; border-top: 1px solid var(--ll-line-soft); }
.ll-chips { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-top: 18px; }
.ll-section .ll-chips { margin-top: 0; }
.ll-chips a, .ll-chips .ll-current {
  display: inline-flex;
  align-items: center;
  min-height: 46px;
  padding: 7px 16px;
  border: 1px solid var(--ll-line);
  border-radius: 5px;
  background: var(--ll-surface);
  color: var(--ll-text);
  font-size: 16px;
  line-height: 1.8;
}
.ll-chips a:hover { border-color: var(--ll-primary-line); background: var(--ll-primary-soft); text-decoration: none; }
.ll-chips .ll-current { border-color: var(--ll-ink); background: var(--ll-surface-soft); color: var(--ll-ink); font-weight: 600; }

/* 长列表、说明和数据表 */
.ll-q-list { border: 1px solid var(--ll-line); border-radius: 8px; overflow: visible; }
.ll-q-list li + li { border-top: 1px solid var(--ll-line-soft); }
.ll-q-list li:first-child a { border-radius: 7px 7px 0 0; }
.ll-q-list li:last-child a { border-radius: 0 0 7px 7px; }
.ll-q-list li a { display: flex; align-items: baseline; gap: 14px; min-height: 60px; padding: 15px 20px; color: var(--ll-ink); font-size: 16px; line-height: 1.8; }
.ll-q-list li:nth-child(even) a { background: var(--ll-surface-soft); }
.ll-q-list li a:hover { background: var(--ll-primary-soft); text-decoration: underline; }
.ll-q-type { flex: none; padding: 1px 9px; border: 1px solid var(--ll-line); border-radius: 4px; background: var(--ll-surface); color: var(--ll-muted); font-size: 14px; line-height: 1.8; }
.ll-table, .ll-my-table { width: 100%; border-collapse: collapse; font-size: 16px; line-height: 1.8; }
.ll-table th, .ll-table td, .ll-my-table th, .ll-my-table td { padding: 14px 16px; border: 1px solid var(--ll-line); text-align: left; }
.ll-table th, .ll-my-table th { background: var(--ll-surface-soft); color: var(--ll-ink); font-weight: 600; }
.ll-table td:first-child { color: var(--ll-ink); font-weight: 600; white-space: nowrap; }
.ll-about { padding: 24px 26px; border: 1px solid var(--ll-line); border-radius: 8px; background: var(--ll-surface); }
.ll-about > h2 { margin-bottom: 18px; }
.ll-about p { margin-bottom: 12px; font-size: 16px; line-height: 1.8; color: var(--ll-text); }
.ll-about p:last-child { margin-bottom: 0; }
.ll-about .ll-table + p { margin-top: 16px; }
.ll-steps { counter-reset: ll-step; margin: 8px 0 18px; }
.ll-steps li { position: relative; min-height: 32px; margin-bottom: 10px; padding-left: 40px; color: var(--ll-text); line-height: 1.8; }
.ll-steps li::before { counter-increment: ll-step; content: counter(ll-step); position: absolute; left: 0; top: 0; width: 28px; height: 28px; border: 1px solid var(--ll-line); border-radius: 5px; background: var(--ll-surface-soft); color: var(--ll-ink); font-size: 14px; font-weight: 600; line-height: 26px; text-align: center; }

/* 详情页：左图右选项，所有答案在首屏；解析按原顺序接续 */
.ll-question, .ll-practice { padding: 22px 24px 26px; border: 1px solid var(--ll-line); border-radius: 8px; background: var(--ll-surface); }
.ll-q-title { margin-bottom: 6px; color: var(--ll-ink); font-size: 25px; font-weight: 700; line-height: 1.7; letter-spacing: -.2px; }
.ll-q-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 0 16px; min-height: 44px; margin-bottom: 14px; color: var(--ll-muted); font-size: 14px; line-height: 1.8; }
.ll-q-meta a { color: var(--ll-muted); }
.ll-q-meta a:hover { color: var(--ll-ink); }
.ll-q-main, .ll-p-main { display: block; }
.ll-q-main.has-img, .ll-p-main.has-img { display: grid; grid-template-columns: 340px minmax(0, 1fr); align-items: start; gap: 22px; }
.ll-q-body, .ll-p-body { min-width: 0; }
.ll-q-main.has-img > .ll-q-body, .ll-p-main.has-img > .ll-p-body { grid-column: 2; grid-row: 1; }
.ll-q-figure { display: flex; align-items: center; justify-content: center; min-width: 0; height: 272px; padding: 8px; border: 1px solid var(--ll-line); border-radius: 6px; background: var(--ll-surface-soft); overflow: hidden; }
.ll-q-main.has-img > .ll-q-figure, .ll-p-main.has-img > .ll-q-figure { grid-column: 1; grid-row: 1; }
.ll-q-figure img { display: block; max-width: 100%; max-height: 100%; width: auto; height: auto; object-fit: contain; color: var(--ll-muted); font-size: 14px; }
.ll-q-options, .ll-p-options { display: grid; gap: 8px; }
.ll-q-options li, .ll-p-options li { position: relative; display: grid; grid-template-columns: 30px minmax(0, 1fr) auto; align-items: center; gap: 10px; min-height: 56px; padding: 10px 12px; border: 1px solid var(--ll-line); border-radius: 6px; background: var(--ll-surface); color: var(--ll-ink); font-size: 17px; line-height: 1.8; }
.ll-q-options li i, .ll-p-options li i { display: inline-flex; align-items: center; justify-content: center; flex: none; width: 30px; height: 30px; border: 1px solid var(--ll-line); border-radius: 5px; background: var(--ll-surface); color: var(--ll-text); font-size: 16px; font-style: normal; font-weight: 600; line-height: 1.8; }
.ll-q-options li.is-right, .ll-p-options li.is-right { border-color: var(--ll-success-line); background: var(--ll-success-soft); }
.ll-q-options li.is-right i, .ll-p-options li.is-right i { border-color: var(--ll-success); background: var(--ll-success); color: var(--ll-on-status); }
.ll-right-tag { position: relative; padding-left: 14px; color: var(--ll-success); font-size: 14px; font-style: normal; font-weight: 600; white-space: nowrap; }
.ll-right-tag::before { content: ""; position: absolute; left: 0; top: 8px; width: 8px; height: 4px; border-left: 2px solid var(--ll-success); border-bottom: 2px solid var(--ll-success); transform: rotate(-45deg); }
.ll-q-answer { display: flex; align-items: center; gap: 12px; min-height: 50px; margin-top: 12px; padding: 8px 14px; border-left: 3px solid var(--ll-success); border-radius: 0 5px 5px 0; background: var(--ll-success-soft); color: var(--ll-success); font-size: 17px; line-height: 1.8; }
.ll-q-answer strong { color: var(--ll-success); font-size: 20px; font-weight: 700; }
.ll-q-block { margin-top: 20px; padding: 18px 20px; border-left: 3px solid var(--ll-line); border-radius: 0 6px 6px 0; background: var(--ll-surface-soft); }
.ll-q-block h2 { margin-bottom: 6px; color: var(--ll-ink); font-size: 18px; font-weight: 600; line-height: 1.8; }
.ll-q-block p { color: var(--ll-text); font-size: 16px; line-height: 1.8; }
.ll-q-block audio { display: block; width: 360px; max-width: 100%; height: 54px; }
.ll-q-block video { display: block; max-width: 100%; }
.ll-q-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; }
.ll-q-nav { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 20px; padding-top: 20px; border-top: 1px solid var(--ll-line); }

/* 做题器：选项内的原生按钮将键盘点击冒泡给原有 li 监听器 */
.ll-practice > .ll-h1 { margin: 0 0 12px; }
.ll-p-top { display: flex; flex-wrap: wrap; align-items: center; gap: 16px 24px; margin-bottom: 20px; padding: 12px 16px; border: 1px solid var(--ll-line-soft); border-radius: 6px; background: var(--ll-surface-soft); color: var(--ll-text); font-size: 16px; line-height: 1.8; }
.ll-p-top > span { display: inline-flex; align-items: center; gap: 12px; }
.ll-p-top select { min-width: 112px; height: 46px; padding: 6px 28px 6px 12px; border: 1px solid var(--ll-line); border-radius: 5px; background: var(--ll-surface); color: var(--ll-ink); font-size: 16px; line-height: 1.8; cursor: pointer; }
.ll-p-top .ll-p-progress { margin-left: auto; color: var(--ll-ink); font-size: 17px; font-weight: 600; }
.ll-practice .ll-q-stem { margin-bottom: 18px; color: var(--ll-ink); font-size: 21px; line-height: 1.8; font-weight: 600; }
.ll-p-options li { display: block; padding: 0; cursor: pointer; }
.ll-option { display: grid; grid-template-columns: 30px minmax(0, 1fr); align-items: center; gap: 12px; width: 100%; min-height: 54px; padding: 10px 12px; border: 0; border-radius: 5px; background: transparent; color: var(--ll-ink); font-size: 17px; line-height: 1.8; text-align: left; cursor: pointer; }
.ll-p-options li:hover { border-color: var(--ll-primary-line); background: var(--ll-primary-soft); }
.ll-p-options li.is-selected { border: 2px solid var(--ll-ink); background: var(--ll-surface-hover); }
.ll-p-options li.is-selected .ll-option { padding: 9px 11px; }
.ll-p-options li.is-selected i { border-color: var(--ll-ink); background: var(--ll-ink); color: var(--ll-on-primary); }
.ll-p-options.is-judged li, .ll-p-options.is-judged .ll-option { cursor: default; }
.ll-p-options.is-judged li:hover { border-color: var(--ll-line); background: var(--ll-surface); }
.ll-p-options.is-judged li.is-right, .ll-p-options.is-judged li.is-right:hover { border: 1px solid var(--ll-success-line); background: var(--ll-success-soft); }
.ll-p-options.is-judged li.is-right .ll-option { padding: 10px 12px; }
.ll-p-options.is-judged li.is-right i { border-color: var(--ll-success); background: var(--ll-success); color: var(--ll-on-status); }
.ll-p-options.is-judged li.is-right::after { content: ""; position: absolute; right: 10px; top: 6px; width: 8px; height: 4px; border-left: 2px solid var(--ll-success); border-bottom: 2px solid var(--ll-success); transform: rotate(-45deg); pointer-events: none; }
.ll-p-options.is-judged li.is-wrong, .ll-p-options.is-judged li.is-wrong:hover { border: 1px dashed var(--ll-error); border-left: 4px solid var(--ll-error); background: var(--ll-error-soft); }
.ll-p-options.is-judged li.is-wrong .ll-option { padding: 10px 12px 10px 9px; }
.ll-p-options.is-judged li.is-wrong i { border-color: var(--ll-error); background: var(--ll-error); color: var(--ll-on-status); }
.ll-p-result { margin-top: 16px; padding: 14px 16px; border-radius: 0 6px 6px 0; font-size: 16px; line-height: 1.8; }
.ll-p-result.is-right { border-left: 4px solid var(--ll-success); background: var(--ll-success-soft); color: var(--ll-success); }
.ll-p-result.is-wrong { border: 1px dashed var(--ll-error-line); border-left: 4px solid var(--ll-error); background: var(--ll-error-soft); color: var(--ll-error); }
.ll-p-bottom { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
.ll-practice > .ll-p-bottom { padding-top: 20px; border-top: 1px solid var(--ll-line); }
.ll-p-tip { margin-top: 20px; padding-top: 16px; border-top: 1px solid var(--ll-line-soft); color: var(--ll-muted); font-size: 14px; line-height: 1.8; }
.ll-p-tip a, .ll-p-empty a { margin-left: 4px; text-decoration: underline; }
.ll-p-empty { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: 4px; min-height: 248px; padding: 48px 24px; border: 1px dashed var(--ll-line); border-radius: 6px; background: var(--ll-surface-soft); color: var(--ll-muted); font-size: 16px; line-height: 1.8; text-align: center; }
.ll-my-list { border: 1px solid var(--ll-line); border-radius: 6px; }
.ll-my-list li { display: flex; align-items: center; justify-content: space-between; font-size: 16px; line-height: 1.8; }
.ll-my-list li + li { border-top: 1px solid var(--ll-line-soft); }
.ll-my-list li a { display: flex; flex: 1; min-height: 60px; padding: 14px 18px; }
.ll-my-list li a:hover { background: var(--ll-primary-soft); }
#ll-my .ll-p-top { justify-content: flex-start; }
#ll-my .ll-p-top > .ll-btn { margin-left: auto; }

@media (prefers-reduced-motion: reduce) {
  .ll-main *, .ll-main *::before, .ll-main *::after { transition: none; }
  .ll-btn:active { transform: none; }
}