/* 统一主题：色值/字体/圆角全部来自 /xuexi/nasm-theme.css（→ DC 令牌）。
   本文件只保留布局，勿再写 :root 色值 —— 改配色改 tokens.css。
   2026-09-30 课程页统一：骨架壳（#bar/#view/#inner 排版/#pager）来自 course-shell.css
   （CPT 母版抽取），本文件的业务样式（阶段卡/题面/目录内容）继续在后面生效。 */
@import url("/xuexi/nasm-theme.css");
@import url("/xuexi/course-shell.css?v=2");

/* 密度对齐 CPT（2026-10-01 用户判「不人性化」）：本文件旧体系以 0.8-0.9rem 小字
   为主体（≈13-14px），CPT 主体 16.5px——提升 html 基准 16→18.5px，全 rem 体系
   等比放大到 CPT 密度（含间距，手机留白同步变舒适）。对齐基准见 course-shell/#inner。 */
html { font-size: 18.5px; }

* {
  box-sizing: border-box;
}

html {
  color: var(--ink);
  font-family: var(--sans);
}

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
}

button,
input {
  font: inherit;
}

button {
  color: inherit;
}

button:focus-visible,
input:focus-visible,
a:focus-visible {
  outline: 3px solid var(--sun);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  top: 1rem;
  left: 1rem;
  z-index: 20;
  padding: 0.7rem 1rem;
  color: var(--paper-light);
  background: var(--ink);
  transform: translateY(-200%);
}

.skip-link:focus {
  transform: translateY(0);
}

.page-shell {
  /* 布局已由 course-shell.css 接管（body block + #main 钉高），此容器不再承载布局 */
}

/* 头部 = 一行：徽章 + 章节名 + 切章按钮。
   原设计是「大徽章 + 106px 大标题 + 大留白」共 282px，把正文挤到 493px 才出现 —— 手机首屏只能看到半个标题 */
.site-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 0 12px;
  background: transparent;
  border-bottom: 1px solid var(--n-border);
}

.brand-lockup,
.nasm-logo {
  display: none;              /* 首屏优先给正文，品牌信息页脚已足够 */
}

.chapter-heading {
  flex: 1;
  min-width: 0;
}

.brand-mark {
  display: grid;
  width: 32px;
  height: 32px;
  flex: none;
  color: var(--paper-light);
  background: var(--signal);
  border-radius: 50%;
  place-items: center;
  font-family: var(--display-sans);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.chapter-heading h1 {
  margin: 0;
  font-family: var(--display-sans);
  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: -0.01em;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.eyebrow,
.panel-kicker {
  margin: 0 0 10px;
  color: var(--signal-dark);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.site-header .eyebrow {
  display: none;              /* CHAPTER 01 与切章按钮重复，标题行省下这行高度 */
}

.header-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  justify-content: flex-end;
  padding-bottom: 5px;
}

.chapter-selector {
  position: relative;
}

/* 目录入口加个列表图标 —— 光写「第1章」看不出它是目录 */
.chapter-menu-button::before {
  content: "☰";
  font-size: 0.85em;
  opacity: 0.85;
}

.chapter-menu-button {
  display: flex;
  gap: 6px;
  align-items: center;
  padding: 6px 11px;
  color: var(--on-accent);
  background: var(--accent);
  border: 1px solid var(--accent);
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 700;
  white-space: nowrap;
  cursor: pointer;
  list-style: none;
}

.chapter-menu-button::-webkit-details-marker {
  display: none;
}

.chapter-menu-button::after {
  width: 7px;
  height: 7px;
  border-right: 1px solid currentColor;
  border-bottom: 1px solid currentColor;
  content: "";
  transform: translateY(-2px) rotate(45deg);
  transition: transform 160ms ease;
}

.chapter-selector[open] .chapter-menu-button::after {
  transform: translateY(2px) rotate(225deg);
}

.duration-badge {
  padding: 4px 10px;
  border: 1px solid var(--n-border-2);
  border-radius: var(--radius-full);
  color: var(--text-muted);
  font-size: 0.7rem;
  font-weight: 600;
  white-space: nowrap;
}

.text-button {
  margin-left: auto;
  padding: 4px 2px;
  color: var(--text-muted);
  background: transparent;
  border: 0;
  font-size: 0.72rem;
  cursor: pointer;
}

.text-button:hover {
  color: var(--accent);
}

.chapter-menu {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  z-index: 20;
  width: min(700px, calc(100vw - 32px));
  padding: 14px;
  color: var(--ink);
  background: var(--paper-light);
  border: 1px solid var(--ink);
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.14);
}

.chapter-menu-header {
  display: flex;
  gap: 12px;
  align-items: center;
  justify-content: space-between;
  padding: 2px 2px 12px;
  border-bottom: 1px solid var(--line);
}

.chapter-menu-header .eyebrow {
  margin: 0;
  font-size: 0.68rem;
}

.chapter-menu-header > span {
  color: var(--ink-soft);
  font-size: 0.65rem;
}













/* 进度行 = 一行元信息 + 满宽细进度条（原设计是两列 grid，手机上多占一行） */
.overall-progress {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 12px;
  padding: 10px 0 12px;
  font-size: 0.74rem;
  font-weight: 700;
}

.overall-progress .progress-track {
  flex: 1 1 100%;
  order: 9;
}

.progress-track {
  height: 5px;
  overflow: hidden;
  background: rgba(0, 0, 0, 0.10);
}

#progress-fill {
  display: block;
  width: 0;
  height: 100%;
  background: var(--signal);
  transition: width 380ms ease;
}

.learning-layout {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 46px;
  padding: 16px 0 40px;
}

.phase-panel {
  display: flex;
  min-height: 100%;
  flex-direction: column;
  border-right: 1px solid var(--line);
  padding-right: 30px;
}

.exam-navigation {
  display: grid;
  gap: 12px;
}

.exam-nav-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  color: var(--ink-soft);
  font-size: 0.68rem;
  font-weight: 700;
}

.exam-question-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(34px, 1fr));
  gap: 7px;
}

.exam-question-button {
  position: relative;
  display: grid;
  min-height: 42px;
  padding: 4px 2px;
  border: 1px solid var(--line);
  cursor: pointer;
  place-items: center;
}

.exam-question-button.is-answered {
  color: var(--accent);
  background: var(--accent-soft);
  border-color: var(--accent);
}

.exam-question-button.is-unanswered {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.72);
}

.exam-question-button.is-current {
  z-index: 1;
  border-color: var(--signal);
  box-shadow: 0 0 0 3px var(--signal);
  transform: translateY(-1px);
}

.exam-question-number {
  font-size: 0.72rem;
  font-weight: 800;
  line-height: 1;
}

.exam-question-state {
  font-size: 0.58rem;
  font-weight: 800;
  line-height: 1;
}

.exam-locked-copy {
  margin: 0;
  color: var(--ink-soft);
  font-size: 0.8rem;
  font-weight: 700;
}

.phase-list {
  display: grid;
  gap: 0;
  padding: 0;
  margin: 0;
  list-style: none;
  counter-reset: phase;
}

.phase-item {
  position: relative;
  display: grid;
  grid-template-columns: 30px 1fr;
  gap: 10px;
  min-height: 72px;
  color: rgba(0, 0, 0, 0.48);
  counter-increment: phase;
}

.phase-link {
  display: block;
  width: 100%;
  padding: 0;
  color: inherit;
  text-align: left;
  background: transparent;
  border: 0;
  cursor: pointer;
}

.phase-link:disabled {
  cursor: not-allowed;
  opacity: 1;
}

.phase-link:not(:disabled):hover strong {
  color: var(--signal-dark);
}

.phase-item::before {
  content: "0" counter(phase);
  z-index: 1;
  display: grid;
  width: 30px;
  height: 30px;
  color: var(--ink-soft);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 50%;
  place-items: center;
  font-family: var(--serif);
  font-size: 0.74rem;
}

.phase-item:not(:last-child)::after {
  position: absolute;
  top: 30px;
  bottom: 0;
  left: 15px;
  width: 1px;
  background: var(--line);
  content: "";
}

.phase-item strong {
  display: block;
  margin-top: 4px;
  font-size: 0.86rem;
}

.phase-item small {
  font-size: 0.68rem;
}

.phase-item.is-active,
.phase-item.is-complete {
  color: var(--ink);
}

.phase-item.is-active::before {
  color: var(--paper-light);
  background: var(--signal);
  border-color: var(--signal);
}

.phase-item.is-complete::before {
  color: var(--paper-light);
  background: var(--moss);
  border-color: var(--moss);
}

.principle-note {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  margin-top: auto;
  padding: 18px 0 0;
  border-top: 1px solid var(--ink);
}

.principle-note[hidden] {
  display: none;
}

.principle-note span {
  color: var(--signal);
  font-family: var(--serif);
  font-size: 2rem;
  line-height: 1;
}

.principle-note p {
  margin: 0;
  font-family: var(--serif);
  font-size: 1.05rem;
  line-height: 1.4;
}

.app-stage {
  min-width: 0;
}

/* 卡片 = DC 玻璃配方（DESIGN.md §1.2）：半透明白渐变 + 背景模糊 + 内顶高光。
   去掉原 520px 的 min-height —— 那是首屏空白的第二个来源 */
.content-card,
.loading-card,
.error-card {
  position: relative;
  overflow: hidden;
  padding: clamp(20px, 4vw, 34px);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.78), rgba(255, 255, 255, 0.58));
  -webkit-backdrop-filter: blur(var(--glass-blur-md)) saturate(var(--glass-saturate)) brightness(var(--glass-brightness));
  backdrop-filter: blur(var(--glass-blur-md)) saturate(var(--glass-saturate)) brightness(var(--glass-brightness));
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow:
    var(--glass-shadow),
    inset 0 1px 0 rgba(255, 255, 255, 0.5);
  animation: card-enter 420ms var(--ease-apple) both;
}

/* 降级：不支持 backdrop-filter 时近实心 */
@supports not ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .content-card,
  .loading-card,
  .error-card {
    background: rgba(255, 255, 255, 0.94);
  }
}

.content-card::after {
  display: none;   /* 原设计右上角的色块：圆角卡片上像渲染 bug，去掉 */
  position: absolute;
  top: 0;
  right: 0;
  width: 94px;
  height: 12px;
  background: var(--signal);
  content: "";
}

.card-index {
  display: inline-flex;
  gap: 10px;
  align-items: baseline;
  color: var(--signal-dark);
  font-weight: 800;
}

.card-index b {
  font-family: var(--serif);
  font-size: 3rem;
  font-weight: 500;
  line-height: 1;
}

.quiz-card .card-index {
  gap: 8px;
  align-items: center;
}

.quiz-card .card-index b {
  font-size: clamp(1.65rem, 2.2vw, 2.15rem);
}

.quiz-card .card-index span {
  font-size: 0.68rem;
  letter-spacing: 0.05em;
}

.content-card h2,
.loading-card h2,
.error-card h2 {
  max-width: 720px;
  margin: 18px 0 24px;
  font-family: var(--display-sans);
  font-size: clamp(2rem, 4vw, 3.5rem);
  font-weight: 600;
  line-height: 1.08;
  letter-spacing: -0.02em;
}

.learning-card > h2 {
  display: block;
  width: fit-content;
  max-width: 100%;
  margin: 16px 0 18px;
  padding: 6px 10px;
  color: var(--signal-dark);
  background: rgba(10, 132, 255, 0.08);
  border-left: 3px solid var(--signal);
  font-size: clamp(0.9rem, 1.4vw, 1.08rem);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: 0;
}

.learning-tier-note {
  width: fit-content;
  margin: -8px 0 18px;
  color: var(--ink-soft);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.learning-tier-note.is-supplemental {
  padding: 5px 8px;
  color: var(--moss-dark);
  background: rgba(13, 148, 136, 0.12);
  border: 1px solid rgba(13, 148, 136, 0.28);
}

.diagnosis-card > h2,
.feedback-card > h2,
.answer-review-card > h2 {
  display: block;
  width: fit-content;
  max-width: 100%;
  margin: 16px 0 18px;
  padding: 6px 10px;
  color: var(--signal-dark);
  background: rgba(10, 132, 255, 0.08);
  border-left: 3px solid var(--signal);
  font-size: clamp(0.9rem, 1.4vw, 1.08rem);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: 0;
}

.card-lead {
  max-width: 720px;
  margin: -8px 0 26px;
  color: var(--ink-soft);
  font-size: 1.05rem;
  line-height: 1.75;
}

.learning-points {
  display: grid;
  gap: 14px;
  max-width: 760px;
  padding: 0;
  margin: 0;
  list-style: none;
}

.learning-points li {
  position: relative;
  padding: 0 0 0 28px;
  font-size: 1rem;
  line-height: 1.72;
}

.learning-points li::before {
  position: absolute;
  top: 0.66em;
  left: 3px;
  width: 9px;
  height: 9px;
  background: var(--moss);
  border-radius: 50%;
  content: "";
}

.learning-points .learning-definition {
  margin-bottom: 8px;
  padding: 20px 24px;
  background: rgba(13, 148, 136, 0.10);
  border-top: 1px solid rgba(13, 148, 136, 0.28);
  border-bottom: 1px solid rgba(13, 148, 136, 0.28);
  font-size: clamp(1.45rem, 2.5vw, 2rem);
  font-weight: 700;
  line-height: 1.42;
  letter-spacing: -0.01em;
}

.learning-points .learning-definition::before {
  display: none;
}

.trap-note {
  max-width: 760px;
  margin: 30px 0 0;
  padding: 18px 20px;
  background: var(--warning-bg);
  border-left: 5px solid var(--signal);
}

.trap-note strong {
  display: block;
  margin-bottom: 5px;
  color: var(--signal-dark);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
}

.trap-note p {
  margin: 0;
  line-height: 1.65;
}

.card-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: space-between;
  margin-top: 38px;
}

.button-primary,
.button-secondary {
  min-height: 44px;
  padding: 11px 22px;
  border: 0;
  border-radius: var(--radius-full);
  font-weight: 600;
  cursor: pointer;
  transition: transform var(--duration-fast) var(--ease),
              background var(--duration-fast) var(--ease),
              box-shadow var(--duration-fast) var(--ease);
}

.button-primary {
  margin-left: auto;
  color: var(--on-accent);
  background: var(--accent);
  box-shadow: 0 2px 10px rgba(10, 132, 255, 0.3);
}

.button-primary:hover:not(:disabled) {
  background: var(--accent-strong);
}

.button-primary:active:not(:disabled) {
  transform: scale(0.97);
}

.button-secondary {
  color: var(--text);
  background: rgba(255, 255, 255, 0.6);
  border: 1px solid var(--glass-border);
}

.button-secondary:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.85);
}

.button-secondary:active:not(:disabled) {
  transform: scale(0.97);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.42;
}

.question-block {
  max-width: 760px;
  margin: 0 0 20px;
  padding: 16px 20px 18px;
  color: var(--text);
  background: var(--accent-soft);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
}

.question-label {
  display: block;
  margin-bottom: 8px;
  color: var(--accent);
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.question-context {
  margin: 0 0 10px;
  color: var(--text-light);
  font-size: 1rem;
  line-height: 1.65;
}

.question-block .question-prompt {
  margin: 0;
  color: var(--text);
  font-family: var(--display-sans);
  font-size: clamp(1.15rem, 1.5vw, 1.3rem);
  font-weight: 600;
  line-height: 1.5;
  letter-spacing: 0;
}

.option-list {
  display: grid;
  gap: 10px;
  max-width: 780px;
  padding: 0;
  margin: 0;
  border: 0;
}

.option-label {
  display: grid;
  grid-template-columns: 30px 1fr;
  gap: 12px;
  align-items: center;
  padding: 13px 16px;
  background: rgba(255, 255, 255, 0.55);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: border-color var(--duration-fast) var(--ease),
              background var(--duration-fast) var(--ease);
}

.option-label:hover {
  border-color: var(--accent);
  background: rgba(255, 255, 255, 0.8);
}

.option-label:has(input:checked) {
  background: var(--accent-soft);
  border-color: var(--accent);
}

.option-label input {
  width: 20px;
  height: 20px;
  margin: 0;
  accent-color: var(--signal);
}

.answer-options {
  display: grid;
  gap: 8px;
  max-width: 780px;
}

.answer-option {
  padding: 12px 16px;
  background: rgba(255, 255, 255, 0.45);
  border: 1px solid transparent;
  line-height: 1.5;
}

.answer-option.is-correct {
  background: var(--success-bg);
  border-color: var(--moss-dark);
  font-weight: 700;
}

.answer-option.is-correct::after {
  float: right;
  content: "正确答案";
  color: var(--moss-dark);
  font-size: 0.72rem;
  font-weight: 800;
}

.answer-option.is-selected-incorrect {
  background: var(--danger-bg);
  border-color: var(--signal);
}

.answer-option.is-selected-incorrect::after {
  float: right;
  content: "你的选择";
  color: var(--signal-dark);
  font-size: 0.72rem;
  font-weight: 800;
}

.answer-summary {
  display: grid;
  gap: 10px;
  max-width: 780px;
  margin-top: 22px;
  padding: 18px 20px;
  background: var(--paper);
  border-left: 5px solid var(--moss);
}

.answer-summary p {
  display: grid;
  grid-template-columns: 92px 1fr;
  gap: 12px;
  margin: 0;
  line-height: 1.55;
}

.answer-summary strong {
  color: var(--ink-soft);
}

.answer-summary .answer-explanation {
  display: block;
  padding-top: 10px;
  border-top: 1px solid var(--line);
}

.review-result {
  width: fit-content;
  padding: 5px 9px;
  font-size: 0.78rem;
}

.review-result.is-correct {
  color: var(--moss-dark);
  background: var(--success-bg);
}

.review-result.is-incorrect {
  color: var(--signal-dark);
  background: var(--danger-bg);
}

.score-stamp {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 6px 12px;
  align-items: baseline;
  padding: 10px 16px;
  color: var(--paper-light);
  background: var(--signal);
  transform: rotate(-1.5deg);
}

.score-stamp b {
  font-family: var(--serif);
  font-size: 2.8rem;
  line-height: 1;
}

.score-stamp .score-ratio {
  font-size: 0.9rem;
  font-weight: 800;
}

.score-stamp .score-label {
  flex-basis: 100%;
  font-size: 0.72rem;
  font-weight: 700;
}

.final-exam-actions {
  gap: 10px;
}

.final-exam-actions .button-primary {
  margin-left: auto;
}

.final-score {
  display: grid;
  grid-template-columns: auto auto;
  gap: 2px 10px;
  align-items: baseline;
  justify-content: start;
  max-width: 780px;
  padding: 22px 24px;
  background: var(--ink);
  color: var(--paper-light);
  border-radius: var(--radius-md);
}

.final-score b {
  color: var(--sun);
  font-family: var(--serif);
  font-size: clamp(3.8rem, 8vw, 6.6rem);
  font-weight: 500;
  line-height: 0.9;
}

.final-score > span {
  font-family: var(--serif);
  font-size: 1.35rem;
}

.final-answer-heading {
  margin: 30px 0 12px;
  font-family: var(--display-sans);
  font-size: 1.3rem;
}

.final-answer-list {
  display: grid;
  max-width: 820px;
  padding: 0;
  margin: 0;
  list-style: none;
  border-top: 2px solid var(--signal);
}

.final-answer-item {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
  padding: 12px 10px;
  border-bottom: 1px solid var(--line);
  line-height: 1.55;
  scroll-margin-top: 24px;
}

.final-answer-item b {
  color: var(--signal-dark);
  font-family: var(--serif);
  font-size: 1.18rem;
  font-weight: 500;
}

.diagnosis-card .score-stamp {
  display: flex;
  width: fit-content;
  margin-top: 18px;
}

.diagnosis-list {
  display: grid;
  gap: 14px;
  max-width: 780px;
  margin-top: 28px;
}

.diagnosis-item {
  padding: 20px;
  background: rgba(255, 255, 255, 0.45);
  border-top: 3px solid var(--signal);
}

.diagnosis-item h3 {
  margin: 0 0 8px;
  font-family: var(--display-sans);
  font-size: 1.4rem;
}

.diagnosis-item p {
  margin: 6px 0;
  line-height: 1.65;
}

.diagnosis-item .misconception {
  color: var(--signal-dark);
  font-size: 0.82rem;
  font-weight: 700;
}

.diagnosis-card-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

.button-card-link {
  padding: 9px 12px;
  color: var(--moss-dark);
  background: var(--paper-light);
  border: 1px solid var(--moss);
  cursor: pointer;
}

.button-card-link:hover {
  color: var(--paper-light);
  background: var(--moss-dark);
}

.next-action {
  color: var(--moss-dark);
  font-weight: 700;
}

.feedback-panel {
  max-width: 780px;
  padding: 24px;
  background: var(--success-bg);
  border-left: 6px solid var(--moss);
}

.feedback-card .feedback-panel {
  margin-top: 18px;
}

.feedback-panel p {
  margin: 0 0 12px;
  font-size: 1.06rem;
  line-height: 1.7;
}

.feedback-panel p:last-child {
  margin-bottom: 0;
}

.memory-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 1px;
  max-width: 820px;
  margin-top: 28px;
  background: var(--line);
  border: 1px solid var(--line);
}

.memory-strip span {
  padding: 15px;
  background: var(--paper-light);
  font-size: 0.78rem;
  font-weight: 700;
  line-height: 1.5;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding-top: 16px;
  color: var(--ink-soft);
  border-top: 1px solid var(--line);
  font-size: 0.72rem;
}

@keyframes card-enter {
  from {
    opacity: 0;
    transform: translateY(14px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 920px) {
  .chapter-menu {
    right: auto;
    left: 0;
    width: min(680px, calc(100vw - 24px));
    padding: 14px;
  }
}

@media (max-width: 760px) {
  body {
    background-position: center, center, 62% top;
    background-attachment: scroll, scroll, scroll;
  }

  .page-shell {
    width: min(100% - 24px, 680px);
    padding-top: 16px;
  }

  .chapter-menu {
    width: min(390px, calc(100vw - 24px));
  }


  .exam-navigation {
    gap: 8px;
  }

  .exam-nav-legend {
    justify-content: flex-end;
  }

  .exam-question-grid {
    grid-template-columns: repeat(10, minmax(28px, 1fr));
    gap: 5px;
  }

  .exam-question-button {
    min-height: 36px;
  }

  .final-score {
    grid-template-columns: auto auto;
    padding: 18px;
  }

  .final-score b {
    font-size: 4rem;
  }

  .final-answer-item {
    grid-template-columns: 34px minmax(0, 1fr);
    padding-right: 0;
    padding-left: 0;
  }

  .content-card,
  .loading-card,
  .error-card {
    min-height: 0;
    padding: 26px 20px;
  }

  .content-card::after {
    width: 68px;
    height: 8px;
  }

  .question-block {
    padding: 16px;
  }

  .card-actions {
    position: sticky;
    bottom: 0;
    z-index: 3;
    margin-right: -20px;
    margin-bottom: -26px;
    margin-left: -20px;
    padding: 12px 20px 16px;
    background: rgba(255, 255, 255, 0.96);
    border-top: 1px solid var(--line);
  }

  .memory-strip {
    grid-template-columns: 1fr 1fr;
  }

  .site-footer {
    flex-direction: column;
  }
}

/* ══════════════════════════════════════════════════════════════════
   页面外壳（2026-09-26 重做 · DC 玻璃拟态）
   ──────────────────────────────────────────────────────────────────
   旧外壳（.site-header 大标题区 / .overall-progress 横杠 / .learning-layout
   侧栏 + .phase-panel 竖排时间轴）在新结构里已不存在，对应规则成了死代码，
   保留在文件前半部分不参与渲染。以下规则覆盖同名残留（.phase-* / .progress-*）。
   ══════════════════════════════════════════════════════════════════ */

.page-shell {
  width: min(720px, calc(100% - 24px));
  margin: 0 auto;
  padding: 12px 0 calc(40px + var(--sb-nav-h, 0px));
}

/* ── 章节头卡：章节名 + 进度 + 四阶段，全收进一张玻璃卡 ── */
.chapter-hero {
  /* backdrop-filter 会创建层叠上下文，不抬 z-index 的话里面的目录面板
     会被后面带 transform 动画的内容卡盖住（实测：面板只露出两行） */
  position: relative;
  z-index: 10;
  margin-bottom: 12px;
  padding: 14px 16px 12px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.72), rgba(255, 255, 255, 0.5));
  -webkit-backdrop-filter: blur(var(--glass-blur-lg)) saturate(var(--glass-saturate)) brightness(var(--glass-brightness));
  backdrop-filter: blur(var(--glass-blur-lg)) saturate(var(--glass-saturate)) brightness(var(--glass-brightness));
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow:
    var(--glass-shadow),
    inset 0 1px 0 rgba(255, 255, 255, 0.55);
}

.hero-top {
  display: flex;
  align-items: center;
  gap: 10px;
}

#chapter-title {
  flex: 1;
  min-width: 0;
  margin: 0;
  font-size: 1.06rem;
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.01em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.hero-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 8px;
  color: var(--text-muted);
  font-size: 0.75rem;
}

.hero-sep {
  opacity: 0.45;
}

/* 进度条：圆角细条 + 渐变填充（旧的 5px 方角实心条） */
.progress-track {
  height: 6px;
  margin-top: 10px;
  background: rgba(0, 0, 0, 0.07);
  border-radius: var(--radius-full);
  overflow: hidden;
}

#progress-fill {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent-strong));
  border-radius: inherit;
  transition: width 380ms var(--ease-apple);
}

/* ── 四阶段：iOS 分段控制器（全屏宽统一，不再用竖排时间轴） ── */
#phase-nav {
  margin-top: 12px;
}

.phase-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 4px;
  margin: 0;
  padding: 4px;
  background: rgba(0, 0, 0, 0.04);
  border-radius: var(--radius-full);
  list-style: none;
  counter-reset: none;
}

.phase-item {
  position: relative;
  display: block;
  min-height: 0;
  color: var(--text-muted);
  font-size: 0.76rem;
  font-weight: 600;
  text-align: center;
}

/* 去掉原时间轴的数字圆点和连接线 */
.phase-item::before,
.phase-item::after {
  content: none;
}

.phase-link {
  display: block;
  width: 100%;
  padding: 7px 2px;
  color: inherit;
  background: transparent;
  border: 0;
  border-radius: var(--radius-full);
  font: inherit;
  text-align: center;
  cursor: pointer;
  transition: background var(--duration-fast) var(--ease), box-shadow var(--duration-fast) var(--ease);
}

.phase-link strong {
  font-weight: inherit;
}

.phase-item small {
  display: none;            /* 「12张短卡」这类副标题在分段控制器里放不下 */
}

.phase-item.is-active .phase-link {
  color: var(--text);
  background: var(--white);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.1);
}

.phase-item.is-complete .phase-link {
  color: var(--success);
}

.phase-link:disabled {
  cursor: default;
  opacity: 0.5;
}

/* ══════════════════════════════════════════════════════════════════
   章节目录面板
   ──────────────────────────────────────────────────────────────────
   旧实现是 position:absolute + right:0 + width:min(700px, …)：
   面板从右侧按钮往左展开，手机上直接撑出视口左边界 → 页面横向滚动
   （用户报「一点开画面就漂移」）。
   改成 fixed + 左右各留 12px，任何屏宽都不溢出。
   ══════════════════════════════════════════════════════════════════ */
.chapter-menu {
  position: fixed;
  top: 60px;
  right: 12px;
  left: 12px;
  z-index: 90;
  width: auto;
  max-height: calc(100vh - 96px);
  margin: 0;
  padding: 14px;
  background: rgba(255, 255, 255, 0.98);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--glass-shadow-lg);
  overflow-y: auto;
  overscroll-behavior: contain;
}

.chapter-menu-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--glass-border);
  color: var(--text-muted);
  font-size: 0.72rem;
}

.chapter-menu-header .eyebrow {
  margin: 0;
  color: var(--text);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: none;
}














@media (min-width: 760px) {
  .chapter-menu {
    right: auto;
    left: auto;
    width: min(480px, 60vw);
    transform: translateX(-50%);
    margin-left: 50%;
  }
}

/* app.js 会主动显示这几个装饰节点（原则提示条 / 侧栏标题 / 章节眉标），
   新结构里不再有它们的位置 —— 用 CSS 按住，避免每次渲染又冒出来 */
#principle-note,
#side-panel-title,
#chapter-eyebrow {
  display: none;
}

/* ── 内容卡内部：卡片头 / 标题 / 要点行 / 误区提示 ──
   原来是一整坨文字堆在白卡里；改成「小标签头 + 独立要点行」，
   和 DC 的卡片语言一致（每块信息有自己的边界） */

.card-index {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 14px;
  padding: 3px 11px;
  color: var(--accent);
  background: var(--accent-soft);
  border-radius: var(--radius-full);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.card-index b {
  font-size: 0.82rem;
  font-weight: 800;
}

.content-card h2 {
  margin: 0 0 16px;
  font-family: var(--display-sans);
  font-size: 1.24rem;
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.01em;
}

.learning-points {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.learning-points li {
  position: relative;
  padding: 12px 15px 12px 35px;
  background: rgba(255, 255, 255, 0.55);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  line-height: 1.68;
}

.learning-points li::before {
  position: absolute;
  top: 19px;
  left: 15px;
  width: 7px;
  height: 7px;
  background: var(--accent);
  border-radius: 50%;
  content: "";
}

/* 定义行是这张卡的题眼，给强调底 */
.learning-points li.learning-definition {
  background: var(--accent-soft);
  border-color: transparent;
  font-weight: 500;
}

.learning-points li.learning-definition::before {
  background: var(--accent-strong);
}

/* 误区提示：语义色半透明底 + 左侧色条 */
.trap-note {
  margin-top: 14px;
  padding: 12px 15px;
  background: var(--warning-bg);
  border-left: 3px solid var(--warning);
  border-radius: var(--radius-sm);
}

.trap-note strong {
  display: block;
  color: var(--warning);
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.trap-note p {
  margin: 6px 0 0;
  color: var(--text-light);
  font-size: 0.88rem;
  line-height: 1.65;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Submitted exam review uses the chapter's existing explanation. */
.mock-review-list { list-style: none; padding: 0; }
.mock-review-item { padding: 16px 0; border-top: 1px solid var(--line); line-height: 1.7; overflow-wrap: anywhere; }
.mock-review-item summary { cursor: pointer; font-weight: 600; }
.mock-review-item p { margin: 12px 0; }
.mock-review-item .button-secondary { display: inline-block; margin: 8px 0; }

.mock-review-item .question-context, .final-result-card > .question-context { color: inherit; }

/* ══ 左侧课程目录（2026-09-30 用户定：所有选择收进目录，打开默认欢迎页） ══ */
#side {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: 300px;
  z-index: 50;
  display: flex;
  flex-direction: column;
  background: rgba(255, 255, 255, 0.94);
  -webkit-backdrop-filter: blur(18px) saturate(1.8);
  backdrop-filter: blur(18px) saturate(1.8);
  border-right: 1px solid var(--n-border, rgba(0, 0, 0, 0.08));
  box-shadow: 6px 0 26px rgba(0, 0, 0, 0.08);
  transform: translateX(-102%);
  transition: transform 0.22s ease;
}
#side.open { transform: none; }
.side-head {
  padding: calc(var(--sb-top-h, 50px) + 14px) 18px 12px;
  border-bottom: 1px solid var(--n-border, rgba(0, 0, 0, 0.08));
}
.side-head .homelink {
  display: inline-block;
  margin-bottom: 9px;
  font-size: 12.5px;
  color: var(--text-light, #4e4e56);
  text-decoration: none;
  opacity: 0.9;
}
.side-head .homelink:hover { color: var(--accent); opacity: 1; }
.side-head h1 { margin: 0 0 4px; font-size: 15px; color: var(--text); cursor: pointer; }
.side-head h1:hover { color: var(--accent); }
.side-head p { margin: 0; font-size: 12px; color: var(--text-muted); }
.side-scroll { flex: 1; overflow-y: auto; overscroll-behavior: contain; padding: 8px 0 30px; }
/* 下拉浮层形态 → 侧栏内静态展开：盖掉原 absolute 定位与双列 */
#side .chapter-selector { position: static; }
#side .chapter-selector > summary { list-style: none; display: none; }
#side .chapter-selector > summary::-webkit-details-marker { display: none; }
#side .chapter-menu {
  position: static;
  width: auto;
  max-height: none;
  padding: 6px 10px 10px;
  background: transparent;
  border: 0;
  box-shadow: none;
  color: var(--text);
}
#mask {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 45;
  background: rgba(0, 0, 0, 0.42);
}
#mask.on { display: block; }
#menu {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  padding: 0;
  border: 1px solid var(--n-border, rgba(0, 0, 0, 0.12));
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.8);
  color: var(--text);
  font-size: 16px;
  cursor: pointer;
  flex: 0 0 auto;
}
#menu:hover { border-color: var(--accent); color: var(--accent); }
/* 欢迎首页：隐藏章内专属元素（进章后 is-home 移除即恢复） */
body.is-home .hero-meta,
body.is-home .progress-track,
body.is-home #phase-nav { display: none; }
/* 欢迎页视觉已收编 course-shell.css（2026-10-01，全课程一份）*/
/* 桌面 / 平板横屏：目录常驻，页面整体右移 */
@media (min-width: 821px) and (min-height: 501px) {
  #side { transform: none; box-shadow: none; }
  #menu { display: none; }
  #mask { display: none !important; }
  body { padding-left: 300px; }
}
@media (max-width: 820px), (orientation: landscape) and (max-height: 500px) {
  .side-head { padding-top: 16px; }
}