/* ============================================================
   优师堂 · 课程详情页 专用样式
   与师资频道详情页同属深蓝冷色系，但主色改用「正蓝」区分：
   讲师页 = 青蓝 teal #2CC6D0 ｜ 课程页 = 正蓝 #14B8A6
   Header/Footer 复用品牌红（见 style.css）
   ============================================================ */

:root {
  --course-primary: #14B8A6;          /* 主色：正蓝 */
  --course-primary-dark: #077A70;     /* 深蓝 */
  --course-primary-light: #8FE4D8;    /* 深底高亮蓝 */
  --course-hero-from: #063F3B;        /* Hero 渐变起 */
  --course-hero-to: #052F2B;          /* Hero 渐变止 */
  --course-gold: #FF6B35;             /* 金色点缀（福利/实操提示） */
}

/* ========== 面包屑 ========== */
.breadcrumb {
  background: #F8FAFC;
  border-bottom: 1px solid #EEF1F4;
}
.breadcrumb__inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  font-size: 13px;
  color: #8A94A6;
}
.breadcrumb a { color: #8A94A6; transition: color .2s; }
.breadcrumb a:hover { color: var(--course-primary); }
.breadcrumb__sep { color: #C4CAD4; }
.breadcrumb__current { color: #3F4161; font-weight: 600; }

/* ========== 课程 Hero ========== */
.course-hero {
  position: relative;
  padding: 56px 0 48px;
  background: linear-gradient(135deg, var(--course-hero-from) 0%, var(--course-hero-to) 100%);
  overflow: hidden;
}
.course-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 18% 25%, rgba(74,144,226,.18) 0%, transparent 55%),
              radial-gradient(ellipse at 82% 75%, rgba(74,144,226,.10) 0%, transparent 45%);
}
.course-hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle at 2px 2px, rgba(255,255,255,.06) 1px, transparent 0);
  background-size: 32px 32px;
}
.course-hero .container { position: relative; z-index: 1; }
.course-hero__series {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  background: rgba(74,144,226,.18);
  border: 1px solid rgba(74,144,226,.4);
  border-radius: 999px;
  font-size: 13px;
  color: var(--course-primary-light);
  font-weight: 600;
  margin-bottom: 18px;
}
.course-hero__series::before {
  content: '';
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--course-primary);
}
.course-hero__title {
  font-size: 34px;
  font-weight: 700;
  color: #fff;
  line-height: 1.35;
  margin-bottom: 16px;
  letter-spacing: -0.5px;
}
.course-hero__desc {
  font-size: 16px;
  color: rgba(255,255,255,.82);
  line-height: 1.8;
  margin-bottom: 24px;
  max-width: 760px;
}
.course-hero__actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  align-items: center;
}

/* 讲师卡（Hero 右侧） */
.course-hero__layout {
  display: flex;
  gap: 40px;
  align-items: center;
}
.course-hero__main { flex: 1; min-width: 0; }
.course-teacher {
  flex: 0 0 300px;
  background: rgba(255,255,255,.06);
  border: 1px solid rgba(255,255,255,.14);
  border-radius: 16px;
  padding: 24px;
  text-align: center;
  backdrop-filter: blur(4px);
}
.course-teacher__avatar {
  width: 96px; height: 96px;
  border-radius: 50%;
  overflow: hidden;
  margin: 0 auto 14px;
  border: 3px solid rgba(74,144,226,.6);
  background: #E8F4F8;
}
.course-teacher__avatar img { width: 100%; height: 100%; object-fit: cover; object-position: center top; }
.course-teacher__label { font-size: 12px; color: rgba(255,255,255,.55); margin-bottom: 4px; }
.course-teacher__name { font-size: 20px; font-weight: 700; color: #fff; margin-bottom: 6px; }
.course-teacher__title {
  font-size: 13px;
  color: rgba(255,255,255,.7);
  line-height: 1.5;
  margin-bottom: 16px;
}
.course-teacher__link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 13px;
  color: var(--course-primary-light);
  font-weight: 600;
  transition: color .2s;
}
.course-teacher__link:hover { color: #fff; }

/* ========== 主体两栏布局：左侧边栏 + 右侧内容 ========== */
.course-main {
  padding: 48px 0 72px;
  background: #F8FAFC;
}
.course-main .container {
  display: flex;
  gap: 32px;
  align-items: flex-start;
}

/* 左侧目录导航 */
.course-toc {
  position: sticky;
  top: 96px;
  flex: 0 0 220px;
  background: #fff;
  border-radius: 12px;
  border: 1px solid #E5E7EB;
  padding: 20px 16px;
  box-shadow: 0 4px 16px rgba(0,0,0,.04);
}
.course-toc__title {
  font-size: 13px;
  font-weight: 700;
  color: #1A2B3C;
  margin-bottom: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid #E5E7EB;
  letter-spacing: .5px;
}
.course-toc__list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.course-toc__item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border-radius: 8px;
  font-size: 14px;
  color: #5A6472;
  font-weight: 500;
  border-left: 3px solid transparent;
  transition: all .2s;
}
.course-toc__item .num {
  font-size: 12px;
  color: #B6BEC9;
  font-weight: 600;
  letter-spacing: .5px;
}
.course-toc__item:hover {
  background: #F8FAFC;
  color: var(--course-primary);
}
.course-toc__item.active {
  background: rgba(74,144,226,.08);
  color: var(--course-primary-dark);
  border-left-color: var(--course-primary);
  font-weight: 600;
}
.course-toc__item.active .num { color: var(--course-primary); }

/* 内容区 */
.course-content { flex: 1; min-width: 0; }

.course-section { margin-bottom: 56px; }
.course-section:last-child { margin-bottom: 0; }
.course-section__title {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 24px;
  font-weight: 700;
  color: #1A2B3C;
  margin-bottom: 24px;
}
.course-section__title .icon {
  flex: 0 0 auto;
  width: 40px; height: 40px;
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, var(--course-primary) 0%, var(--course-primary-dark) 100%);
  color: #fff;
}
.course-section__title .en { font-size: 13px; font-weight: 500; color: #9AA4B2; margin-left: auto; letter-spacing: 1px; }

/* ========== 课程背景 / 痛点 ========== */
.pain-lead {
  font-size: 15px;
  color: #3F4161;
  line-height: 1.9;
  margin-bottom: 20px;
}
.pain-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-bottom: 20px;
}
.pain-card {
  background: #fff;
  border: 1px solid #E8EBEF;
  border-left: 3px solid var(--course-primary);
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 2px 8px rgba(0,0,0,.03);
}
.pain-card__title {
  font-size: 15px;
  font-weight: 700;
  color: #1A2B3C;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.pain-card__title .dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: #077A70;
  flex: 0 0 auto;
}
.pain-card__desc { font-size: 13.5px; color: #5A6472; line-height: 1.75; }
/* 痛点清单卡（纯问句痛点合并） */
.pain-card--list { grid-column: 1 / -1; }
.pain-card__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px 20px;
}
.pain-card__list li {
  position: relative;
  padding-left: 16px;
  font-size: 13.5px;
  color: #5A6472;
  line-height: 1.7;
}
.pain-card__list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 9px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--course-primary);
  opacity: .6;
}
@media (max-width: 560px) {
  .pain-card__list { grid-template-columns: 1fr; }
}
.pain-conclusion {
  background: linear-gradient(135deg, rgba(74,144,226,.08) 0%, rgba(47,107,192,.06) 100%);
  border: 1px solid rgba(74,144,226,.25);
  border-radius: 12px;
  padding: 18px 22px;
  font-size: 14.5px;
  color: #3F4161;
  line-height: 1.85;
}
.pain-conclusion strong { color: var(--course-primary-dark); }

/* ========== 课程安排 ========== */
.arrange-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.arrange-card {
  background: #fff;
  border: 1px solid #E8EBEF;
  border-radius: 14px;
  padding: 22px;
  text-align: center;
}
.arrange-card__icon {
  width: 44px; height: 44px;
  margin: 0 auto 12px;
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  background: rgba(74,144,226,.12);
  color: var(--course-primary-dark);
}
.arrange-card__title {
  font-size: 13px;
  color: #9AA4B2;
  margin-bottom: 6px;
}
.arrange-card__value {
  font-size: 15px;
  color: #1A2B3C;
  font-weight: 600;
  line-height: 1.5;
}
.arrange-card__value .big {
  font-size: 24px;
  color: var(--course-primary);
  font-weight: 700;
}

/* ========== 课程收益 ========== */
.benefit-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.benefit-card {
  background: #fff;
  border: 1px solid #E8EBEF;
  border-radius: 14px;
  padding: 22px;
  transition: transform .25s, box-shadow .25s, border-color .25s;
}
.benefit-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 28px rgba(0,0,0,.08);
  border-color: rgba(74,144,226,.4);
}
.benefit-card__icon {
  width: 44px; height: 44px;
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  background: rgba(74,144,226,.12);
  color: var(--course-primary-dark);
  margin-bottom: 14px;
}
.benefit-card__title { font-size: 16px; font-weight: 700; color: #1A2B3C; margin-bottom: 8px; }
.benefit-card__desc { font-size: 13.5px; color: #5A6472; line-height: 1.75; }
/* 无标题收益卡：图标+描述横向紧凑布局 */
.benefit-card--plain {
  display: flex;
  align-items: center;
  gap: 14px;
}
.benefit-card--plain .benefit-card__icon {
  margin-bottom: 0;
  flex: 0 0 auto;
}
.benefit-card--plain .benefit-card__desc {
  margin: 0;
  flex: 1;
}

/* ========== 课程大纲（手风琴） ========== */
.outline-item {
  background: #fff;
  border: 1px solid #E8EBEF;
  border-radius: 14px;
  margin-bottom: 16px;
  overflow: hidden;
  transition: border-color .25s, box-shadow .25s;
}
.outline-item:last-child { margin-bottom: 0; }
.outline-item.open { border-color: rgba(74,144,226,.4); box-shadow: 0 6px 20px rgba(0,0,0,.05); }
.outline-item__header {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 20px 22px;
  cursor: pointer;
  text-align: left;
  background: #fff;
  transition: background .2s;
}
.outline-item__header:hover { background: #F7FAFB; }
.outline-item__num {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 4px 14px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--course-primary) 0%, var(--course-primary-dark) 100%);
  color: #fff;
  font-size: 13px;
  font-weight: 700;
  white-space: nowrap;
}
.outline-item__title {
  flex: 1;
  font-size: 16px;
  font-weight: 700;
  color: #1A2B3C;
  line-height: 1.5;
}
.outline-item__toggle {
  flex: 0 0 auto;
  width: 28px; height: 28px;
  display: flex; align-items: center; justify-content: center;
  color: #8A94A6;
  transition: transform .25s;
}
.outline-item.open .outline-item__toggle { transform: rotate(180deg); color: var(--course-primary-dark); }
.outline-item__body {
  display: none;
  padding: 4px 22px 24px;
  border-top: 1px dashed #E8EBEF;
}
.outline-item.open .outline-item__body { display: block; }

.outline-chapter { margin-top: 18px; }
.outline-chapter__title {
  font-size: 15px;
  font-weight: 700;
  color: var(--course-primary-dark);
  margin-bottom: 10px;
  padding-left: 12px;
  border-left: 3px solid var(--course-primary);
  line-height: 1.5;
}
.outline-list { margin-bottom: 8px; }
.outline-list li {
  font-size: 14px;
  color: #3F4161;
  line-height: 1.8;
  padding: 3px 0 3px 4px;
  position: relative;
}
.outline-list > li { font-weight: 500; }
.outline-list ul { margin: 2px 0 4px 18px; }
.outline-list ul li { font-weight: 400; color: #5A6472; }
.outline-list ul li::before {
  content: '';
  position: absolute;
  left: -12px; top: 12px;
  width: 5px; height: 5px;
  border-radius: 50%;
  background: #C4CAD4;
}
.outline-note {
  font-size: 13px;
  color: var(--course-gold);
  background: rgba(201,162,39,.08);
  border: 1px solid rgba(201,162,39,.22);
  border-radius: 8px;
  padding: 8px 14px;
  margin-top: 10px;
  display: inline-block;
}
.outline-deliver {
  margin-top: 18px;
  padding: 14px 18px;
  background: linear-gradient(135deg, rgba(74,144,226,.08) 0%, rgba(47,107,192,.05) 100%);
  border-radius: 10px;
  font-size: 13.5px;
  color: var(--course-primary-dark);
  font-weight: 600;
}

/* ========== 课程福利 ========== */
.welfare-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.welfare-card {
  background: #fff;
  border: 1px solid #E8EBEF;
  border-radius: 14px;
  padding: 22px;
  display: flex;
  gap: 16px;
  align-items: flex-start;
}
.welfare-card__icon {
  flex: 0 0 auto;
  width: 46px; height: 46px;
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  background: rgba(201,162,39,.12);
  color: var(--course-gold);
}
.welfare-card__body { flex: 1; }
.welfare-card__title { font-size: 16px; font-weight: 700; color: #1A2B3C; margin-bottom: 8px; }
.welfare-card__desc { font-size: 13.5px; color: #5A6472; line-height: 1.75; }

/* ========== 其他课程推荐 ========== */
.course-others {
  padding: 56px 0 72px;
  background: #fff;
}
.course-others__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 32px;
}
.course-other-card {
  display: flex;
  flex-direction: column;
  background: #F8FAFC;
  border: 1px solid #E8EBEF;
  border-radius: 14px;
  padding: 22px;
  transition: transform .25s, box-shadow .25s, border-color .25s;
}
.course-other-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 28px rgba(0,0,0,.08);
  border-color: rgba(74,144,226,.4);
}
.course-other-card__tag {
  display: inline-block;
  align-self: flex-start;
  padding: 3px 10px;
  border-radius: 6px;
  background: rgba(74,144,226,.12);
  color: var(--course-primary-dark);
  font-size: 12px;
  font-weight: 600;
  margin-bottom: 12px;
}
.course-other-card__title {
  font-size: 16px;
  font-weight: 700;
  color: #1A2B3C;
  line-height: 1.5;
  margin-bottom: 8px;
}
.course-other-card__desc {
  font-size: 13px;
  color: #5A6472;
  line-height: 1.7;
  margin-bottom: 14px;
  flex: 1;
}
.course-other-card__link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 13px;
  color: var(--course-primary);
  font-weight: 600;
}
.course-other-card__link:hover { color: var(--course-primary-dark); }

/* ========== 响应式 ========== */
@media (max-width: 1024px) {
  .course-hero__layout { flex-direction: column; }
  .course-teacher { flex: 1 1 auto; width: 100%; }
  .course-hero__title { font-size: 26px; }
  .benefit-grid { grid-template-columns: repeat(2, 1fr); }
  .pain-grid { grid-template-columns: 1fr; }
  .welfare-grid { grid-template-columns: 1fr; }
  .course-others__grid { grid-template-columns: 1fr; }
  .course-main .container { flex-direction: column; }
  .course-toc {
    position: relative;
    top: 0;
    flex: 0 0 auto;
    width: 100%;
  }
  .course-toc__list { flex-direction: row; flex-wrap: wrap; }
}
@media (max-width: 560px) {
  .benefit-grid { grid-template-columns: 1fr; }
  .arrange-grid { grid-template-columns: 1fr; }
  .course-hero__title { font-size: 22px; }
  .course-hero__actions { flex-direction: column; align-items: stretch; }
}