/**
 * @file learn.css
 * @description 学习中心专用样式：课程目录、课时阅读、随堂测验、学习档案与登录表单。
 *              复用 styles.css 的设计 Token 与 pages.css 的通用组件，不重复定义。
 * @author QQQ Dev Team
 * @created 2026-11-03
 */

/* hidden 属性需高于组件 display 声明 */
[data-learn-page] [hidden] {
  display: none !important;
}

/* ============================================================
 * 学习中心首屏与概览
 * ============================================================ */
.learn-hero-note {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  padding: 14px 18px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--blue);
  background: var(--surface);
}

.learn-hero-note span {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  color: var(--ink-3);
}

.learn-hero-note strong {
  color: var(--ink);
  font-weight: 600;
}

.learn-intro {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  gap: clamp(28px, 4vw, 64px);
  align-items: start;
}

.learn-intro-copy {
  display: grid;
  gap: 16px;
}

.learn-intro-copy p {
  color: var(--ink-3);
  line-height: 1.95;
}

.learn-intro-list {
  display: grid;
  gap: 1px;
  border: 1px solid var(--line);
  background: var(--line);
}

.learn-intro-list div {
  display: grid;
  gap: 3px;
  padding: 15px 18px;
  background: var(--surface);
}

.learn-intro-list dt {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.14em;
  color: var(--blue);
}

.learn-intro-list dd {
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--ink-2);
}

/* ============================================================
 * 课程卡片
 * ============================================================ */
.course-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  border: 1px solid var(--line);
  background: var(--line);
}

.course-card {
  display: grid;
  align-content: start;
  gap: 14px;
  padding: 26px 24px 24px;
  background: var(--surface);
  transition: background 0.25s;
}

.course-card:hover {
  background: #fff;
}

.course-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.course-code {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.14em;
  color: var(--ink-4);
}

.course-level {
  padding: 4px 9px;
  border: 1px solid rgba(44, 107, 168, 0.28);
  border-radius: 2px;
  background: var(--blue-wash);
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.08em;
  color: var(--blue-deep);
}

.course-card h3 {
  font-family: var(--serif);
  font-size: 1.35rem;
  font-weight: 600;
  line-height: 1.35;
}

.course-subtitle {
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--ink-4);
}

.course-summary {
  font-size: 13.5px;
  line-height: 1.85;
  color: var(--ink-3);
}

.course-outcomes {
  display: grid;
  gap: 6px;
  padding: 12px 14px;
  border-left: 2px solid var(--line-strong);
  background: var(--paper);
}

.course-outcomes li {
  position: relative;
  padding-left: 14px;
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--ink-3);
}

.course-outcomes li::before {
  content: '';
  position: absolute;
  top: 8px;
  left: 0;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--blue);
}

.course-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.06em;
  color: var(--ink-4);
}

.course-meta span {
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.course-meta i {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--line-strong);
}

.course-card .btn {
  justify-self: start;
  margin-top: 2px;
}

/* 学习路径 */
.path-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.path-card {
  display: grid;
  align-content: start;
  gap: 12px;
  padding: 24px;
  border: 1px solid var(--line);
  background: var(--surface);
}

.path-index {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  color: var(--blue);
}

.path-card h3 {
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 600;
}

.path-card p {
  font-size: 13px;
  line-height: 1.85;
  color: var(--ink-3);
}

.path-steps {
  display: grid;
  gap: 7px;
  padding-top: 6px;
  border-top: 1px solid var(--line-soft);
}

.path-steps li {
  display: flex;
  gap: 8px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--ink-2);
}

.path-steps span {
  flex-shrink: 0;
  font-family: var(--mono);
  font-size: 10px;
  color: var(--ink-4);
}

/* ============================================================
 * 加载与空状态
 * ============================================================ */
.learn-state {
  display: grid;
  justify-items: center;
  gap: 12px;
  padding: 56px 24px;
  border: 1px dashed var(--line-strong);
  background: var(--surface);
  text-align: center;
}

.learn-state strong {
  font-family: var(--serif);
  font-size: 1.1rem;
}

.learn-state p {
  max-width: 44em;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--ink-3);
}

.learn-state[hidden] {
  display: none;
}

/* 纵向区块堆叠 */
.learn-stack {
  display: grid;
  gap: 26px;
}

.learn-section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 12px 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.learn-section-head .mono-label {
  display: block;
  margin-bottom: 4px;
}

.learn-section-head h2 {
  font-family: var(--serif);
  font-size: 1.5rem;
  font-weight: 600;
  line-height: 1.3;
}

/* 课时页顶部留白 */
.lesson-page {
  padding-top: calc(var(--header-h) + 52px);
  padding-bottom: clamp(48px, 6vw, 80px);
}

/* 登录页顶部留白 */
.auth-page {
  padding-top: calc(var(--header-h) + 60px);
  padding-bottom: clamp(48px, 6vw, 80px);
}

/* ============================================================
 * 课程详情
 * ============================================================ */
.course-detail-head {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
  gap: clamp(28px, 4vw, 60px);
  align-items: start;
}

.course-detail-head h1 {
  font-family: var(--serif);
  font-size: clamp(1.8rem, 3.4vw, 2.8rem);
  font-weight: 600;
  line-height: 1.3;
}

.course-detail-summary {
  margin-top: 14px;
  font-size: 14.5px;
  line-height: 1.9;
  color: var(--ink-3);
}

.course-facts {
  display: grid;
  gap: 1px;
  border: 1px solid var(--line);
  background: var(--line);
}

.course-facts div {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 16px;
  background: var(--surface);
}

.course-facts dt {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.14em;
  color: var(--blue);
}

.course-facts dd {
  font-size: 12.5px;
  color: var(--ink-2);
  text-align: right;
}

.lesson-list-block {
  display: grid;
  gap: 1px;
  border: 1px solid var(--line);
  background: var(--line);
}

.lesson-row {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr) auto;
  gap: 18px;
  align-items: center;
  padding: 18px 20px;
  background: var(--surface);
  transition: background 0.2s;
}

.lesson-row:hover {
  background: #fff;
}

.lesson-row-index {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-4);
}

.lesson-row-body {
  display: grid;
  gap: 4px;
}

.lesson-row-body strong {
  font-family: var(--serif);
  font-size: 1.05rem;
  font-weight: 600;
}

.lesson-row-body span {
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--ink-4);
}

.lesson-row-side {
  display: grid;
  justify-items: end;
  gap: 6px;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 10px;
  border: 1px solid var(--line);
  border-radius: 2px;
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.06em;
  color: var(--ink-4);
}

.status-pill--done {
  border-color: rgba(47, 125, 91, 0.3);
  background: rgba(47, 125, 91, 0.08);
  color: var(--green);
}

.status-pill--doing {
  border-color: rgba(44, 107, 168, 0.3);
  background: var(--blue-wash);
  color: var(--blue-deep);
}

/* 进度条 */
.progress-track {
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: var(--line-soft);
  overflow: hidden;
}

.progress-fill {
  width: 0;
  height: 100%;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--blue-bright), var(--blue-deep));
  transition: width 0.45s var(--ease-out);
}

.progress-line {
  display: flex;
  align-items: center;
  gap: 12px;
}

.progress-line .progress-track {
  flex: 1;
}

.progress-line span {
  flex-shrink: 0;
  font-family: var(--mono);
  font-size: 10px;
  color: var(--ink-3);
}

/* ============================================================
 * 课时阅读
 * ============================================================ */
.lesson-layout {
  display: grid;
  grid-template-columns: 244px minmax(0, 1fr);
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
}

.lesson-side {
  position: sticky;
  top: calc(var(--header-h) + 24px);
  display: grid;
  gap: 14px;
  padding-right: 8px;
}

.lesson-side-title {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.16em;
  color: var(--ink-4);
}

.lesson-side a {
  display: grid;
  gap: 3px;
  padding: 10px 0 10px 14px;
  border-left: 2px solid var(--line);
  transition: border-color 0.2s, color 0.2s;
}

.lesson-side a strong {
  font-size: 13px;
  font-weight: 500;
  line-height: 1.5;
  color: var(--ink-2);
}

.lesson-side a small {
  font-family: var(--mono);
  font-size: 9.5px;
  color: var(--ink-4);
}

.lesson-side a:hover,
.lesson-side a.is-active {
  border-left-color: var(--blue);
}

.lesson-side a:hover strong,
.lesson-side a.is-active strong {
  color: var(--blue);
}

.lesson-main {
  min-width: 0;
}

.lesson-head {
  display: grid;
  gap: 12px;
  padding-bottom: 22px;
  border-bottom: 1px solid var(--line);
}

.lesson-breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.06em;
  color: var(--ink-4);
}

.lesson-breadcrumb a {
  color: var(--ink-4);
}

.lesson-breadcrumb a:hover {
  color: var(--blue);
}

.lesson-head h1 {
  font-family: var(--serif);
  font-size: clamp(1.65rem, 3vw, 2.35rem);
  font-weight: 600;
  line-height: 1.35;
}

.lesson-head-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.lesson-objectives {
  display: grid;
  gap: 7px;
  margin-top: 18px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  background: var(--surface);
}

.lesson-objectives strong {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.14em;
  color: var(--blue);
}

.lesson-objectives li {
  position: relative;
  padding-left: 16px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--ink-3);
}

.lesson-objectives li::before {
  content: '';
  position: absolute;
  top: 9px;
  left: 0;
  width: 6px;
  height: 1px;
  background: var(--ink-4);
}

/* 正文排版 */
.lesson-body {
  padding-top: 8px;
  font-size: 15px;
  line-height: 1.95;
  color: var(--ink-2);
}

.lesson-body p {
  margin: 14px 0;
}

.lesson-body h3 {
  margin: 30px 0 4px;
  font-family: var(--serif);
  font-size: 1.2rem;
  font-weight: 600;
  line-height: 1.45;
  color: var(--ink);
}

.lesson-body h3::before {
  content: '';
  display: block;
  width: 28px;
  height: 2px;
  margin-bottom: 10px;
  background: var(--blue);
}

.lesson-body strong {
  font-weight: 600;
  color: var(--ink);
}

.lesson-body a {
  color: var(--blue);
  border-bottom: 1px solid rgba(44, 107, 168, 0.35);
}

.lesson-list,
.lesson-steps {
  display: grid;
  gap: 8px;
  margin: 16px 0;
  padding: 18px 20px;
  border: 1px solid var(--line-soft);
  background: var(--surface);
}

.lesson-list li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  line-height: 1.8;
}

.lesson-list li::before {
  content: '';
  position: absolute;
  top: 11px;
  left: 0;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--blue);
}

.lesson-steps {
  counter-reset: lesson-step;
}

.lesson-steps li {
  position: relative;
  padding-left: 34px;
  font-size: 14px;
  line-height: 1.8;
  counter-increment: lesson-step;
}

.lesson-steps li::before {
  content: counter(lesson-step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 0;
  font-family: var(--mono);
  font-size: 10px;
  color: var(--blue);
}

.lesson-note {
  margin: 22px 0;
  padding: 16px 20px;
  border-left: 3px solid var(--seal);
  background: rgba(168, 69, 58, 0.06);
  font-size: 13.5px;
  line-height: 1.85;
  color: var(--ink-2);
}

.lesson-note strong {
  color: var(--seal);
}

/* 课时操作区 */
.lesson-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-top: 28px;
  padding: 18px 20px;
  border: 1px solid var(--line);
  background: var(--surface);
}

.lesson-actions p {
  flex: 1;
  min-width: 220px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--ink-3);
}

.lesson-pager {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-top: 20px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.lesson-pager a {
  display: grid;
  gap: 3px;
  max-width: 46%;
}

.lesson-pager a:last-child {
  justify-items: end;
  text-align: right;
}

.lesson-pager span {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.1em;
  color: var(--ink-4);
}

.lesson-pager strong {
  font-family: var(--serif);
  font-size: 1rem;
  font-weight: 600;
}

.lesson-pager a:hover strong {
  color: var(--blue);
}

/* ============================================================
 * 随堂测验
 * ============================================================ */
.quiz-panel {
  margin-top: 36px;
  padding: 24px;
  border: 1px solid var(--line);
  border-top: 2px solid var(--blue);
  background: var(--surface);
}

.quiz-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line-soft);
}

.quiz-head h2 {
  font-family: var(--serif);
  font-size: 1.25rem;
  font-weight: 600;
}

.quiz-head span {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  color: var(--ink-4);
}

.quiz-question {
  display: grid;
  gap: 12px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line-soft);
}

.quiz-question > strong {
  font-size: 14.5px;
  font-weight: 600;
  line-height: 1.7;
}

.quiz-question > strong em {
  margin-right: 8px;
  font-family: var(--mono);
  font-size: 10px;
  font-style: normal;
  color: var(--blue);
}

.quiz-options {
  display: grid;
  gap: 8px;
}

.quiz-option {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 11px 14px;
  border: 1px solid var(--line);
  background: var(--paper);
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--ink-2);
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s;
}

.quiz-option:hover {
  border-color: var(--line-strong);
}

.quiz-option input {
  margin-top: 3px;
  accent-color: var(--blue);
}

.quiz-option.is-correct {
  border-color: rgba(47, 125, 91, 0.45);
  background: rgba(47, 125, 91, 0.08);
}

.quiz-option.is-wrong {
  border-color: rgba(168, 69, 58, 0.4);
  background: rgba(168, 69, 58, 0.07);
}

.quiz-explain {
  display: none;
  margin-top: 4px;
  padding: 10px 12px;
  border-left: 2px solid var(--line-strong);
  background: var(--paper);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--ink-3);
}

.quiz-question.is-graded .quiz-explain {
  display: block;
}

.quiz-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  padding-top: 18px;
}

.quiz-footer p {
  flex: 1;
  min-width: 200px;
  font-size: 12.5px;
  color: var(--ink-4);
}

.quiz-result {
  margin-top: 16px;
  padding: 14px 16px;
  border: 1px solid var(--line);
  background: var(--paper);
  font-size: 13.5px;
  line-height: 1.8;
}

.quiz-result strong {
  font-family: var(--serif);
  font-size: 1.05rem;
}

.quiz-result[hidden] {
  display: none;
}

/* ============================================================
 * 登录 / 注册
 * ============================================================ */
.auth-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: clamp(32px, 5vw, 72px);
  align-items: start;
}

.auth-info {
  display: grid;
  gap: 18px;
}

.auth-info h1 {
  font-family: var(--serif);
  font-size: clamp(1.8rem, 3.2vw, 2.6rem);
  font-weight: 600;
  line-height: 1.3;
}

.auth-info p {
  font-size: 14px;
  line-height: 1.95;
  color: var(--ink-3);
}

.auth-benefits {
  display: grid;
  gap: 12px;
  padding-top: 8px;
}

.auth-benefits li {
  display: grid;
  grid-template-columns: 26px minmax(0, 1fr);
  gap: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-2);
}

.auth-benefits span {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--blue);
}

.auth-card {
  display: grid;
  gap: 18px;
  padding: 26px;
  border: 1px solid var(--line);
  border-top: 2px solid var(--blue);
  background: var(--surface);
}

.auth-oauth {
  justify-content: center;
  width: 100%;
}

.auth-oauth[hidden],
.auth-oauth-hint[hidden],
.auth-divider[hidden] {
  display: none;
}

.auth-oauth-hint {
  margin-top: -6px;
}

.auth-divider {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  color: var(--ink-4);
}

.auth-divider::before,
.auth-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--line);
}

.auth-tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border: 1px solid var(--line);
}

.auth-tab {
  padding: 11px 12px;
  border: 0;
  background: var(--paper);
  font-size: 13px;
  color: var(--ink-3);
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}

.auth-tab[aria-selected='true'] {
  background: var(--surface);
  color: var(--blue-deep);
  font-weight: 600;
  box-shadow: inset 0 -2px 0 var(--blue);
}

.learn-form {
  display: grid;
  gap: 14px;
}

.learn-field {
  display: grid;
  gap: 5px;
}

.learn-field label {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.12em;
  color: var(--ink-3);
}

.learn-field input {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--line-strong);
  background: var(--surface);
  font-size: 14px;
  color: var(--ink);
  transition: border-color 0.2s;
}

.learn-field input:focus {
  border-color: var(--blue);
  outline: none;
}

.learn-field input[aria-invalid='true'] {
  border-color: var(--seal);
}

.learn-field small {
  min-height: 15px;
  font-size: 11.5px;
  color: var(--seal);
}

.learn-field-hint {
  font-size: 11.5px;
  line-height: 1.6;
  color: var(--ink-4);
}

.learn-form .btn {
  justify-content: center;
  width: 100%;
}

.learn-form-message {
  display: none;
  padding: 11px 13px;
  border: 1px solid var(--line);
  background: var(--paper);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--ink-2);
}

.learn-form-message.is-visible {
  display: block;
}

.learn-form-message.is-error {
  border-color: rgba(168, 69, 58, 0.35);
  background: rgba(168, 69, 58, 0.07);
  color: var(--seal);
}

.learn-form-message.is-success {
  border-color: rgba(47, 125, 91, 0.35);
  background: rgba(47, 125, 91, 0.07);
  color: var(--green);
}

.auth-session {
  display: grid;
  gap: 14px;
}

.auth-session-user {
  display: grid;
  gap: 3px;
  padding: 14px 16px;
  border: 1px solid var(--line);
  background: var(--paper);
}

.auth-session-user span {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.12em;
  color: var(--ink-4);
}

.auth-session-user strong {
  font-family: var(--serif);
  font-size: 1.05rem;
}

.auth-session-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.auth-foot {
  font-size: 12px;
  line-height: 1.75;
  color: var(--ink-4);
}

/* ============================================================
 * 我的学习
 * ============================================================ */
.record-stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  border: 1px solid var(--line);
  background: var(--line);
}

.record-stat {
  display: grid;
  gap: 4px;
  padding: 20px;
  background: var(--surface);
}

.record-stat span {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.12em;
  color: var(--ink-4);
}

.record-stat strong {
  font-family: var(--serif);
  font-size: 1.7rem;
  font-weight: 600;
  line-height: 1.2;
}

.record-stat small {
  font-size: 11.5px;
  color: var(--ink-3);
}

.record-list {
  display: grid;
  gap: 14px;
}

.record-course {
  display: grid;
  gap: 12px;
  padding: 20px;
  border: 1px solid var(--line);
  background: var(--surface);
}

.record-course-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
}

.record-course-head strong {
  font-family: var(--serif);
  font-size: 1.1rem;
  font-weight: 600;
}

.record-course-head span {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--ink-4);
}

.record-course-foot {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 16px;
  font-size: 12px;
  color: var(--ink-3);
}

.record-course-foot a {
  color: var(--blue);
}

.record-course-foot a:hover {
  text-decoration: underline;
}

.attempt-table td,
.attempt-table th {
  white-space: nowrap;
}

.attempt-score {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--green);
}

.attempt-score.is-low {
  color: var(--seal);
}

/* ============================================================
 * 响应式
 * ============================================================ */
@media (max-width: 1024px) {
  .course-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .path-grid {
    grid-template-columns: 1fr;
  }

  .learn-intro,
  .course-detail-head,
  .auth-layout {
    grid-template-columns: 1fr;
  }

  .lesson-layout {
    grid-template-columns: 1fr;
  }

  .lesson-side {
    position: static;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    padding-right: 0;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--line);
  }

  .lesson-side-title {
    width: 100%;
  }

  .lesson-side a {
    padding: 8px 11px;
    border: 1px solid var(--line);
    background: var(--surface);
  }

  .lesson-side a.is-active {
    border-color: var(--blue);
  }

  .record-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  .course-grid {
    grid-template-columns: 1fr;
  }

  .lesson-row {
    grid-template-columns: 38px minmax(0, 1fr);
    gap: 12px;
  }

  .lesson-row-side {
    grid-column: 2;
    justify-items: start;
  }

  .lesson-body {
    font-size: 14.5px;
  }

  .lesson-body h3 {
    font-size: 1.1rem;
  }

  .quiz-panel {
    padding: 18px 16px;
  }

  .auth-card {
    padding: 20px 16px;
  }

  .record-stats {
    grid-template-columns: 1fr 1fr;
  }

  .lesson-pager {
    flex-direction: column;
  }

  .lesson-pager a,
  .lesson-pager a:last-child {
    max-width: none;
    justify-items: start;
    text-align: left;
  }
}

/* ============================================================
 * 修复：.auth-benefits 的 li 为两列栅格，但内部是「编号 + 标题 + 正文」
 * 三部分，正文（文本节点）会被当成第三个 grid item 塞进 26px 的
 * 编号列，导致每行仅一个字。改为「绝对定位编号 + 块级正文」。
 * ============================================================ */
.auth-benefits li {
  display: block;
  position: relative;
  padding-left: 34px;
  font-size: 13px;
  line-height: 1.75;
  color: var(--ink-2);
}

.auth-benefits li span {
  position: absolute;
  left: 0;
  top: 2px;
  font-family: var(--mono);
  font-size: 10px;
  color: var(--blue);
}

.auth-benefits li strong {
  margin-right: 2px;
}

/* ============================================================
 * 课时正文排版：代码块、行宽与要点区
 * ============================================================ */

/* 代码块：等宽、可横向滚动、左侧蓝色标记 */
.lesson-body .code-block {
  margin: 18px 0;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--blue);
  border-radius: 2px;
  background: #f2efe7;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.lesson-body .code-block code {
  display: block;
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.8;
  color: var(--ink-2);
  white-space: pre;
  tab-size: 2;
}

/* 正文行宽：中文一行 36–40 字最舒服，避免通栏 */
@media (min-width: 900px) {
  .lesson-body {
    max-width: 74ch;
  }
}

/* 移动端代码块缩小字号，减少横向滚动 */
@media (max-width: 640px) {
  .lesson-body .code-block {
    padding: 12px 12px;
    margin: 14px 0;
  }

  .lesson-body .code-block code {
    font-size: 11px;
    line-height: 1.7;
  }
}

/* 课时正文的要点列表：自定义圆点，避免被全局 ul 重置吃掉 */
.lesson-body .bullet-list {
  margin: 16px 0;
  padding-left: 4px;
  list-style: none;
}

.lesson-body .bullet-list li {
  position: relative;
  padding-left: 18px;
  margin-bottom: 10px;
  font-size: 14px;
  line-height: 1.85;
  color: var(--ink-2);
}

.lesson-body .bullet-list li::before {
  content: '';
  position: absolute;
  left: 2px;
  top: 11px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--blue);
  opacity: 0.5;
}

.lesson-body .bullet-list li:last-child {
  margin-bottom: 0;
}

/* ============================================================
 * 课程目录分组布局
 * 十几门课混排会行尾留空，按类别分组后每组独立成网格。
 * ============================================================ */

/* 外层容器改为纵向堆叠，取消原来的三列 */
#courseGrid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) !important;
  gap: clamp(34px, 4vw, 52px);
  border: 0;
  background: transparent;
}

/* 组标题 */
.course-group-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.course-group-head h3 {
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  margin-bottom: 6px;
}

.course-group-head p {
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--ink-3);
}

.course-group-count {
  flex: none;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  color: var(--ink-4);
  padding-bottom: 3px;
}

/* 组内网格：列数由 JS 按课程数量设定，保证每行排满 */
/* 统一以 3 列为基准，最后一行自动拉伸填满，避免各组宽度不一致 */
.course-rows {
  display: flex;
  flex-wrap: wrap;
  gap: 1px;
  border: 1px solid var(--line);
  background: var(--line);
}

.course-rows .course-card {
  flex: 1 1 calc((100% - 2px) / 3);
  min-width: 0;
}

/* 最后一行被拉伸时，内容保持阅读宽度，不跟着铺满 */
.course-rows .course-card > h3,
.course-rows .course-card > p,
.course-rows .course-card > ul {
  max-width: 46ch;
}

/* 卡片纵向排列，按钮贴底，同一行高度一致 */
#courseGrid .course-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

#courseGrid .course-card > a:last-child {
  margin-top: auto;
  align-self: flex-start;
}

/* 移动端：每组单列，去掉外边框避免拥挤 */
@media (max-width: 860px) {
  #courseGrid {
    gap: 30px;
  }

  .course-rows {
    grid-template-columns: minmax(0, 1fr) !important;
  }

  .course-group-head {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }
}

/* 课时正文的操作步骤：有序列表 */
.lesson-body .step-list {
  margin: 16px 0;
  padding-left: 24px;
  list-style: decimal;
}

.lesson-body .step-list li {
  margin-bottom: 9px;
  font-size: 14px;
  line-height: 1.85;
  color: var(--ink-2);
  padding-left: 2px;
}

.lesson-body .step-list li::marker {
  color: var(--blue);
  font-family: var(--mono);
  font-size: 12px;
}

/* ============================================================
 * 课时正文表格：窄屏下保证每列可读，超出则横向滚动
 * 5 列表格若压进 390px，每列只剩 70px，中文会变成竖排。
 * ============================================================ */
.lesson-body .table-wrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.lesson-body .table-wrap .data-table {
  min-width: 640px;
  width: auto;
}

@media (max-width: 640px) {
  .lesson-body .table-wrap .data-table {
    min-width: 560px;
    font-size: 11.5px;
  }

  .lesson-body .table-wrap .data-table th,
  .lesson-body .table-wrap .data-table td {
    padding: 9px 12px;
    vertical-align: top;
  }

  /* 首列（编号）不参与换行，避免挤压 */
  .lesson-body .table-wrap .data-table td:first-child {
    white-space: nowrap;
    width: 1%;
  }
}

/* ============================================================
 * 移动端：表格转卡片
 * 5 列长文本在 390px 下必然把中文压成竖排，改为每行一张卡、
 * 字段名在左、内容在右。
 * ============================================================ */
@media (max-width: 640px) {
  .lesson-body .table-wrap {
    overflow: visible;
    border: 0;
    background: transparent;
  }

  .lesson-body .table-wrap .data-table,
  .lesson-body .table-wrap .data-table tbody,
  .lesson-body .table-wrap .data-table tr,
  .lesson-body .table-wrap .data-table td {
    display: block;
    width: 100%;
    min-width: 0;
  }

  .lesson-body .table-wrap .data-table thead {
    display: none;
  }

  .lesson-body .table-wrap .data-table tr {
    border: 1px solid var(--line);
    border-radius: 3px;
    background: var(--surface);
    margin-bottom: 10px;
    padding: 4px 14px;
  }

  .lesson-body .table-wrap .data-table td {
    display: grid;
    grid-template-columns: 74px minmax(0, 1fr);
    gap: 10px;
    padding: 8px 0;
    border: 0;
    border-bottom: 1px dashed var(--line-soft);
    font-size: 12.5px;
    line-height: 1.72;
  }

  .lesson-body .table-wrap .data-table td:last-child {
    border-bottom: 0;
  }

  .lesson-body .table-wrap .data-table td::before {
    content: attr(data-label);
    font-family: var(--mono);
    font-size: 9.5px;
    letter-spacing: 0.06em;
    color: var(--ink-4);
    padding-top: 3px;
  }

  /* 编号列（无字段名）单独一行，蓝色小字 */
  .lesson-body .table-wrap .data-table td[data-label=""] {
    display: block;
    font-family: var(--mono);
    font-size: 10px;
    color: var(--blue);
    letter-spacing: 0.1em;
    padding-bottom: 2px;
  }

  .lesson-body .table-wrap .data-table td[data-label=""]::before {
    content: none;
  }
}

/* 课时正文中的编号小标题（如「（3）<figure> / <figcaption>」） */
.lesson-body .sub-heading {
  margin: 26px 0 10px;
  font-family: var(--serif);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--ink);
  padding-left: 10px;
  border-left: 2px solid var(--blue);
}

/* ============================================================
 * 代码块语法高亮配色（浅色代码底 #f2efe7）
 * ============================================================ */
.tok-k { color: #a03a5e; }                      /* 关键字 */
.tok-s { color: #2f7d4f; }                      /* 字符串 */
.tok-n { color: #b4650a; }                      /* 数字 */
.tok-c { color: #8b9098; font-style: italic; }  /* 注释 */
.tok-t { color: #2c6ba8; font-weight: 600; }    /* 标签名 */
.tok-a { color: #7a4fa3; }                      /* 属性名 */

/* ============================================================
 * 课时配图：系统界面截图
 * ============================================================ */
.lesson-body .lesson-figure {
  margin: 22px 0;
  border: 1px solid var(--line);
  border-radius: 3px;
  overflow: hidden;
  background: var(--surface);
}

.lesson-body .lesson-figure img {
  display: block;
  width: 100%;
  height: auto;
  border-bottom: 1px solid var(--line);
}

.lesson-body .lesson-figure figcaption {
  padding: 10px 14px;
  font-size: 12px;
  line-height: 1.7;
  color: var(--ink-3);
  background: var(--paper-deep);
}

/* 移动端：截图按比例缩放，避免横向溢出 */
@media (max-width: 640px) {
  .lesson-body .lesson-figure {
    margin: 18px 0;
  }

  .lesson-body .lesson-figure figcaption {
    padding: 9px 12px;
    font-size: 11.5px;
  }
}