/* =========================================================
   清晨教育 - 非标机械设计培训 首页样式
   蓝白色调 · 简洁大气 · 响应式
   ========================================================= */

:root {
  --blue: #0b63e5;
  --blue-dark: #0a4cb0;
  --blue-deep: #0a2540;
  --blue-light: #e8f1ff;
  --bg-alt: #f5f8fd;
  --text: #1f2d3d;
  --text-sub: #5b6b7f;
  --white: #ffffff;
  --border: #e3eaf3;
  --radius: 14px;
  --shadow: 0 8px 30px rgba(11, 99, 229, 0.08);
  --shadow-hover: 0 14px 40px rgba(11, 99, 229, 0.16);
  --transition: all 0.3s ease;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  line-height: 1.7;
  background: var(--white);
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }

.container {
  width: 100%;
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 24px;
}

.text-blue { color: var(--blue); }
.center { text-align: center; margin-top: 40px; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  border: 2px solid transparent;
  transition: var(--transition);
  white-space: nowrap;
}
.btn-lg { padding: 15px 36px; font-size: 16px; }
.btn-primary {
  background: var(--blue);
  color: var(--white);
  box-shadow: 0 6px 18px rgba(11, 99, 229, 0.28);
}
.btn-primary:hover { background: var(--blue-dark); transform: translateY(-2px); }
.btn-outline {
  border-color: var(--blue);
  color: var(--blue);
  background: var(--white);
}
.btn-outline:hover { background: var(--blue); color: var(--white); transform: translateY(-2px); }
.btn-white { background: var(--white); color: var(--blue); }
.btn-white:hover { transform: translateY(-2px); box-shadow: 0 10px 24px rgba(0,0,0,0.18); }
.btn-ghost { border-color: rgba(255,255,255,0.6); color: var(--white); }
.btn-ghost:hover { background: rgba(255,255,255,0.12); }

/* ---------- 头部导航 ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}
.site-header.scrolled { box-shadow: 0 4px 20px rgba(10, 37, 64, 0.08); }
.header-inner {
  display: flex;
  align-items: center;
  gap: 32px;
  height: 72px;
}
.logo img { height: 44px; width: auto; }
.main-nav { flex: 1; }
.main-nav ul { display: flex; gap: 8px; }
.main-nav a {
  display: block;
  padding: 8px 16px;
  font-size: 15px;
  color: var(--text);
  border-radius: 8px;
  transition: var(--transition);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.nav-toggle span {
  width: 24px; height: 2px;
  background: var(--blue-deep);
  border-radius: 2px;
  transition: var(--transition);
}

/* ---------- 授课模式与教学体系 ---------- */
.teach-flow {
  display: flex;
  align-items: stretch;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 56px;
}
.teach-flow:last-child { margin-bottom: 0; }
.teach-flow li:not(.teach-flow-arrow) {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 24px;
  text-align: center;
  min-width: 160px;
  font-size: 16px;
  font-weight: 600;
  color: var(--blue-deep);
  box-shadow: var(--shadow);
  transition: var(--transition);
}
.teach-flow li:not(.teach-flow-arrow):hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-4px);
}
.teach-flow-num {
  display: block;
  margin-bottom: 6px;
  color: var(--blue);
  font-size: 22px;
  font-weight: 800;
}
.teach-flow-copy strong { font-weight: inherit; }
.teach-flow-copy small { display: none; }
.teach-flow-arrow {
  align-self: center;
  color: var(--blue);
  font-size: 22px;
  font-weight: 700;
}

@media (max-width: 768px) {
  .teach-system-sec .section-head { margin-bottom: 18px; }
  .teach-flow {
    position: relative;
    display: flex;
    flex-direction: column;
    flex-wrap: nowrap;
    align-items: stretch;
    justify-content: flex-start;
    gap: 0;
    margin-bottom: 16px;
    padding: 12px 14px;
    background: linear-gradient(180deg, #f6faff 0%, #ffffff 100%);
    border: 1px solid #e6eef9;
    border-radius: 16px;
    box-shadow: 0 10px 28px rgba(10, 76, 176, 0.07);
  }
  .teach-flow:last-child { margin-bottom: 0; }
  .teach-flow::before {
    content: "";
    position: absolute;
    top: 34px;
    bottom: 34px;
    left: 30px;
    width: 2px;
    background: linear-gradient(180deg, var(--blue) 0%, #9bc8ff 100%);
    opacity: 0.42;
  }
  .teach-flow-arrow { display: none; }
  .teach-flow li:not(.teach-flow-arrow) {
    display: grid;
    grid-template-columns: 32px minmax(0, 1fr);
    align-items: center;
    gap: 12px;
    width: 100%;
    max-width: none;
    min-width: 0;
    min-height: 52px;
    padding: 6px 0;
    background: transparent;
    border: 0;
    border-radius: 0;
    box-shadow: none;
    text-align: left;
    font-size: 14px;
    line-height: 1.45;
  }
  .teach-flow li:not(.teach-flow-arrow):hover {
    box-shadow: none;
    transform: none;
  }
  .teach-flow-num {
    position: relative;
    z-index: 1;
    display: flex;
    flex: 0 0 32px;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    margin: 0;
    border: 3px solid var(--white);
    border-radius: 50%;
    background: linear-gradient(135deg, #2e83f6 0%, var(--blue) 55%, var(--blue-dark) 100%);
    box-shadow: 0 5px 14px rgba(11, 99, 229, 0.24);
    color: var(--white);
    font-size: 11px;
    font-weight: 800;
    line-height: 1;
  }
  .teach-flow-copy {
    display: flex;
    min-width: 0;
    flex-direction: column;
    gap: 2px;
  }
  .teach-flow-copy strong {
    color: var(--blue-deep);
    font-size: 14px;
    line-height: 1.35;
  }
  .teach-flow-copy small {
    display: block;
    color: var(--text-sub);
    font-size: 12px;
    line-height: 1.45;
  }
}

/* ---------- 小屏能力清单：两列紧凑排布 ---------- */
@media (max-width: 768px) {
  #skills.section {
    padding: 32px 0;
  }

  #skills .section-head {
    margin-bottom: 20px;
  }

  #skills .section-head h2 {
    text-wrap: balance;
  }

  #skills .section-head h2::after {
    margin-top: 10px;
  }

  .grid.skill-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
  }

  .skill-list .skill-item {
    padding: 12px 14px;
    border-left-width: 3px;
  }

  .skill-list .skill-item b {
    font-size: 14px;
    line-height: 1.45;
  }
}

@media (max-width: 480px) {
  #skills.section {
    padding: 24px 0;
  }

  #skills .section-head {
    margin-bottom: 16px;
  }

  #skills .section-head h2::after {
    margin-top: 8px;
  }

  .grid.skill-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px;
  }

  .skill-list .skill-item {
    padding: 10px 12px;
  }
}




/* ---------- 导航搜索框（与导航链接同一水平线，位于"联系我们"之后） ---------- */
.main-nav { display: flex; align-items: center; gap: 12px; }
.main-nav ul { flex: 1; justify-content: flex-end; }
.nav-search {
  display: flex;
  align-items: center;
  flex-shrink: 0;
  border: 1px solid var(--border);
  border-radius: 999px;
  overflow: hidden;
  background: var(--bg-alt);
  transition: var(--transition);
}
.nav-search:focus-within { border-color: var(--blue); background: var(--white); }
.nav-search input {
  border: none;
  outline: none;
  background: transparent;
  padding: 8px 4px 8px 16px;
  font-size: 14px;
  width: 150px;
  font-family: inherit;
  color: var(--text);
}
.nav-search button {
  border: none;
  background: transparent;
  cursor: pointer;
  padding: 8px 12px 8px 6px;
  font-size: 14px;
}

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(160deg, #f2f7ff 0%, #ffffff 55%, #eaf2ff 100%);
  padding: 72px 0 0;
  overflow: hidden;
}
.hero-inner {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 56px;
  align-items: center;
}
.hero-tag {
  display: inline-block;
  background: var(--blue-light);
  color: var(--blue);
  font-size: 14px;
  font-weight: 600;
  padding: 6px 16px;
  border-radius: 999px;
  margin-bottom: 22px;
}
.hero h1 {
  font-size: 44px;
  line-height: 1.3;
  color: var(--blue-deep);
  letter-spacing: 1px;
  margin-bottom: 18px;
}
.hero-sub { font-size: 16px; color: var(--text-sub); margin-bottom: 32px; }
/* Hero 副标题列表：保留圆点，不使用全局 ul 的无序列表重置 */
.hero-sub-list { list-style: disc; padding-left: 1.2em; color: var(--text); }
.hero-sub-list li::marker { color: var(--blue-deep); }
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 30px; }
.hero-points { display: flex; gap: 24px; flex-wrap: wrap; }
.hero-points li {
  position: relative;
  padding-left: 22px;
  font-size: 14px;
  color: var(--text-sub);
}
.hero-points li::before {
  content: "";
  position: absolute;
  left: 0; top: 7px;
  width: 12px; height: 12px;
  border-radius: 50%;
  background: var(--blue);
  box-shadow: 0 0 0 4px var(--blue-light);
}
/* 1. 容器：锁定比例，防止高度塌陷、变形 */
.hero-media {
  width: 100%;
  max-width: 720px;      /* 与原图最大宽度一致 */
  aspect-ratio: 3 / 2;   /* 720 : 480，锁定原始比例 */
  overflow: hidden;      /* 配合圆角裁剪 */
  border-radius: 20px;   /* 圆角放到容器上更稳妥 */
  line-height: 0;        /* 消除 inline 元素底部空隙 */
}

/* 2. 视频：填满容器，不拉伸 */
.hero-media video,
.hero-media img {
  display: block;        /* 关键：去掉 inline 造成的底部间隙 */
  width: 100%;
  height: 100%;
  object-fit: cover;     /* 保持比例裁剪填充；不想裁剪就改成 contain */
  border-radius: inherit;/* 继承容器圆角 */
}

/* ---------- 数据统计条 ---------- */
.stats-bar {
  margin: 56px 0;
  background: var(--blue-deep);
  border-radius: var(--radius);
  padding: 30px 40px 34px;
  color: var(--white);
}
.stats-title {
  text-align: center;
  font-size: 14px;
  letter-spacing: 4px;
  color: rgba(255,255,255,0.65);
  margin-bottom: 20px;
}
.stats-list {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 20px;
  text-align: center;
}
.stats-list strong {
  display: block;
  font-size: 22px;
  color: #5ea2ff;
  line-height: 1.2;
}
.stats-list span { font-size: 13px; color: rgba(255,255,255,0.78); }

/* ---------- 通用版块 ---------- */
.section { padding: 48px 0; }
.section-alt { background: var(--bg-alt); }
.section-head { text-align: center; max-width: 760px; margin: 0 auto 36px; }
.section-head h2 {
  font-size: 32px;
  color: var(--blue-deep);
  margin-bottom: 12px;
  position: relative;
  display: inline-block;
}
.section-head h2::after {
  content: "";
  display: block;
  width: 56px; height: 4px;
  background: var(--blue);
  border-radius: 2px;
  margin: 14px auto 0;
}
.section-head p { color: var(--text-sub); font-size: 16px; }

/* ---------- 栅格 ---------- */
.grid { display: grid; gap: 24px; }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-5 { grid-template-columns: repeat(5, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

/* ---------- 四项核心能力 ---------- */
.ability-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 26px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}
.ability-card::before {
  content: "";
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 4px;
  background: linear-gradient(90deg, var(--blue), #5ea2ff);
  transform: scaleX(0);
  transform-origin: left;
  transition: var(--transition);
}
.ability-card:hover { box-shadow: var(--shadow-hover); transform: translateY(-6px); }
.ability-card:hover::before { transform: scaleX(1); }
.ability-num {
  font-size: 34px;
  font-weight: 800;
  color: var(--blue-light);
  -webkit-text-stroke: 1px var(--blue);
  display: block;
  margin-bottom: 12px;
}
.ability-card h3 { font-size: 20px; color: var(--blue-deep); margin-bottom: 10px; }
.ability-card p { font-size: 14px; color: var(--text-sub); }
.formula {
  text-align: center;
  margin-top: 44px;
  font-size: 18px;
  font-weight: 600;
  color: var(--blue-deep);
  border-radius: 999px;
  padding: 16px 28px;
}

/* ---------- Tab 切换 ---------- */
.tab-btns {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 36px;
}
.tab-btn {
  padding: 12px 26px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text-sub);
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 999px;
  cursor: pointer;
  transition: var(--transition);
}
.tab-btn:hover { color: var(--blue); border-color: var(--blue); }
.tab-btn.active {
  background: var(--blue);
  color: var(--white);
  border-color: var(--blue);
  box-shadow: 0 6px 16px rgba(11, 99, 229, 0.3);
}
.tab-panel {
  display: none;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--shadow);
}
.tab-panel.active { display: grid; animation: fadeUp 0.45s ease; }
.tab-media img { border-radius: 10px; }
.tab-body h3 { font-size: 24px; color: var(--blue-deep); margin-bottom: 12px; }
.tab-body > p { color: var(--text-sub); margin-bottom: 18px; }
.case-req { background: var(--blue-light); border-radius: 10px; padding: 12px 16px; }

.check-list { margin-bottom: 26px; }
.check-list.cols-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px 20px;
}
.check-list li {
  position: relative;
  padding-left: 24px;
  font-size: 15px;
  color: var(--text);
  line-height: 1.9;
}
.check-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--blue);
  font-weight: 700;
}

/* ---------- 职业晋升 ---------- */
.career { background: linear-gradient(135deg, var(--blue-deep) 0%, #123a6b 100%); }
.career .section-head h2 { color: var(--white); }
.career .section-head p { color: rgba(255,255,255,0.7); }
.career-path {
  display: flex;
  align-items: stretch;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}
.career-path li:not(.career-arrow) {
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.18);
  border-radius: var(--radius);
  padding: 26px 30px;
  text-align: center;
  min-width: 180px;
  backdrop-filter: blur(6px);
  transition: var(--transition);
}
.career-path li:not(.career-arrow):hover {
  background: rgba(255,255,255,0.16);
  transform: translateY(-4px);
}
.career-step { display: block; color: rgba(255,255,255,0.85); font-size: 15px; margin-bottom: 8px; }
.career-path strong { font-size: 26px; color: #6fb0ff; }
.career-arrow {
  align-self: center;
  color: #6fb0ff;
  font-size: 24px;
  font-weight: 700;
}

/* ---------- 能力清单 ---------- */
.skill-list { counter-reset: skill; }
.skill-item {
  background: #e8f1ff;
  border: 1px solid var(--border);
  border-left: 4px solid var(--blue);
  border-radius: 10px;
  padding: 20px 22px;
  font-size: 15px;
  font-weight: 500;
  transition: var(--transition);
}
.skill-item:hover { box-shadow: var(--shadow-hover); transform: translateX(4px); }

/* ---------- 学员作业 ---------- */
.work-card {
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--white);
  border: 1px solid var(--border);
  transition: var(--transition);
}
.work-card:hover { box-shadow: var(--shadow-hover); transform: translateY(-6px); }
.work-card img { aspect-ratio: 3/2; object-fit: cover; width: 100%; }
.work-card figcaption {
  padding: 16px 20px;
  font-size: 15px;
  font-weight: 600;
  color: var(--blue-deep);
  text-align: center;
}

/* ---------- 为什么选择我们 ---------- */
.why-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: var(--transition);
}
.why-card:hover { box-shadow: var(--shadow-hover); transform: translateY(-6px); border-color: transparent; }
.why-icon {
  width: 56px; height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  background: var(--blue-light);
  border-radius: 14px;
  margin-bottom: 18px;
}
.why-card h3 { font-size: 19px; color: var(--blue-deep); margin-bottom: 10px; }
.why-card p { font-size: 14px; color: var(--text-sub); }

.teacher { margin-top: 72px; text-align: center; }
.teacher-title {
  font-size: 28px;
  color: var(--blue-deep);
  margin-bottom: 16px;
  position: relative;
  display: inline-block;
}
.teacher-title::after {
  content: "";
  display: block;
  width: 56px; height: 4px;
  background: var(--blue);
  border-radius: 2px;
  margin: 12px auto 0;
}
.teacher-desc {
  max-width: 760px;
  margin: 0 auto 44px;
  color: var(--text-sub);
  font-size: 16px;
}
.teacher-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 28px;
}
.teacher-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
  text-align: left;
}
.teacher-card:hover { box-shadow: var(--shadow-hover); transform: translateY(-6px); }
.teacher-card img {
  width: 100%;
  aspect-ratio: 1/1;
  object-fit: cover;
}
.teacher-info { padding: 22px 24px 26px; }
.teacher-info h4 { font-size: 19px; color: var(--blue-deep); margin-bottom: 6px; }
.teacher-role {
  display: inline-block;
  font-size: 13px;
  color: var(--blue);
  background: var(--blue-light);
  border-radius: 999px;
  padding: 3px 12px;
  margin-bottom: 12px;
}
.teacher-bio { font-size: 14px; color: var(--text-sub); }

/* ---------- 师资展示轮播（首页 / 关于我们公共） ---------- */
.teacher-carousel { overflow: hidden; }
.teacher-track {
  display: flex;
  gap: 24px;
  transition: transform 0.5s ease;
  will-change: transform;
}
.teacher-slide {
  flex: 0 0 calc((100% - 72px) / 4);
  min-width: 0;
}
.teacher-photo {
  position: relative;
  margin: 0;
  border-top-left-radius: var(--radius);
  border-top-right-radius: var(--radius);
  overflow: hidden;
  line-height: 0;
  background: var(--bg-alt);
}
.teacher-photo img {
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
}
.teacher-tag {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  background: var(--blue);
  color: var(--white);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 3px;
  padding: 10px 12px;
  border-radius: 8px;
  writing-mode: vertical-rl;
  box-shadow: 0 4px 12px rgba(11, 99, 229, 0.35);
}
.teacher-bar {
  background: var(--blue);
  color: var(--white);
  border-bottom-left-radius: var(--radius);
  border-bottom-right-radius: var(--radius);
  padding: 14px 12px 16px;
  text-align: center;
}
.teacher-bar p {
  font-size: 14px;
  line-height: 1.9;
  white-space: nowrap;
}
.teacher-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin-top: 32px;
}

/* ---------- 学员评价轮播（Trustpilot 风格） ---------- */
.review-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
  max-width: 1400px;
  margin: 0 auto 36px;
  padding: 0 4px;
}
.review-score { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.review-brand {
  background: var(--blue);
  color: var(--white);
  font-weight: 700;
  font-size: 15px;
  padding: 8px 18px;
  border-radius: 8px;
}
.review-rating .stars { font-size: 22px; letter-spacing: 2px; }
.review-rating strong { font-size: 22px; color: var(--blue-deep); margin-left: 8px; }
.review-rating p { font-size: 13px; color: var(--text-sub); }

.stars { color: #00b67a; }

.carousel { position: relative; overflow: hidden; }
.carousel-track {
  display: flex;
  gap: 24px;
  transition: transform 0.5s ease;
}
.review-card {
  flex: 0 0 30.5%;
  min-width: 0;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 26px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
}
.review-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}
.review-top .stars { font-size: 18px; letter-spacing: 2px; }
.verified {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 12px;
  color: #00b67a;
  background: rgba(0, 182, 122, 0.1);
  border-radius: 999px;
  padding: 3px 10px;
  white-space: nowrap;
}
.review-card h3 {
  font-size: 17px;
  color: var(--blue-deep);
  margin-bottom: 10px;
  line-height: 1.5;
}
.review-card > p {
  font-size: 14px;
  color: var(--text-sub);
  margin-bottom: 22px;
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 6;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.review-card footer { display: flex; align-items: center; gap: 12px; }
.avatar {
  width: 44px; height: 44px;
  border-radius: 50%;
  background: var(--blue);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  font-weight: 700;
  flex-shrink: 0;
}
.review-card footer strong { display: block; font-size: 14px; color: var(--blue-deep); }
.review-card footer time { font-size: 12px; color: var(--text-sub); }
.carousel-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin-top: 28px;
}
.carousel-btn {
  width: 42px; height: 42px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--white);
  color: var(--blue);
  font-size: 22px;
  cursor: pointer;
  transition: var(--transition);
  line-height: 1;
}
.carousel-btn:hover { background: var(--blue); color: var(--white); border-color: var(--blue); }
.carousel-dots { display: flex; gap: 8px; }
.carousel-dots button {
  width: 10px; height: 10px;
  border-radius: 50%;
  border: none;
  background: #c9d9f2;
  cursor: pointer;
  transition: var(--transition);
  padding: 0;
}
.carousel-dots button.active { background: var(--blue); width: 26px; border-radius: 5px; }

/* ---------- 兼职反馈 ---------- */
.part-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
}
.part-card:hover { box-shadow: var(--shadow-hover); transform: translateY(-6px); }
.part-card img { aspect-ratio: 3/2; object-fit: cover; width: 100%; }
.part-body { padding: 22px 24px; }
.part-body h3 { font-size: 17px; color: var(--blue-deep); margin-bottom: 8px; }
.part-pay { font-size: 14px; color: var(--text-sub); }
.part-pay strong { color: var(--blue); font-size: 20px; }

/* ---------- 知识库 ---------- */
.tab-panel > .kb-grid { grid-column: 1 / -1; }
.kb-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}
.kb-card {
  display: grid;
  grid-template-columns: 200px 1fr;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
}
.kb-card:hover { box-shadow: var(--shadow-hover); transform: translateY(-4px); }
.kb-card img { width: 100%; height: 100%; object-fit: cover; }
.kb-body { padding: 22px 24px; }
.kb-body h3 { font-size: 16px; line-height: 1.5; margin-bottom: 8px; }
.kb-body h3 a:hover { color: var(--blue); }
.kb-body time { font-size: 12px; color: var(--text-sub); display: block; margin-bottom: 10px; }
.kb-body p { font-size: 13px; color: var(--text-sub); display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }

/* ---------- CTA 横幅 ---------- */
.cta-band {
  background: linear-gradient(120deg, var(--blue) 0%, var(--blue-dark) 60%, var(--blue-deep) 100%);
  padding: 80px 0;
  text-align: center;
  color: var(--white);
}
.cta-inner h2 { font-size: 34px; margin-bottom: 12px; }
.cta-inner p { font-size: 17px; color: rgba(255,255,255,0.85); margin-bottom: 32px; }
.cta-inner .hero-actions { justify-content: center; margin-bottom: 0; }

/* ---------- 页脚 ---------- */
.site-footer { background: var(--blue-deep); color: rgba(255,255,255,0.75); }
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.4fr;
  gap: 40px;
  padding: 64px 24px 48px;
}
.footer-brand img { height: 52px; width: auto; border-radius: 8px; padding: 4px 10px; margin-bottom: 16px; }
.footer-brand p { font-size: 14px; line-height: 1.9; }
.footer-col h3 { color: var(--white); font-size: 16px; margin-bottom: 18px; }
.footer-col ul li { margin-bottom: 10px; font-size: 14px; }
.footer-col a:hover { color: #6fb0ff; }

/* 页脚二维码展示区 */
.footer-qr {
  display: flex;
  gap: 20px;
  margin-top: 22px;
  padding-top: 20px;
  border-top: 1px solid rgba(255,255,255,0.12);
}
.footer-qr-item { text-align: center; }
.footer-qr-item img {
  width: 96px; height: 96px;
  background: #fff;
  border-radius: 10px;
  padding: 6px;
  margin-bottom: 8px;
}
.footer-qr-item p { font-size: 12px; color: rgba(255,255,255,0.65); line-height: 1.5; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.12);
  padding: 20px 0;
  text-align: center;
  font-size: 13px;
  color: rgba(255,255,255,0.5);
}

/* ---------- 返回顶部 ---------- */
.back-top {
  position: fixed;
  right: 28px; bottom: 28px;
  width: 46px; height: 46px;
  border-radius: 50%;
  border: none;
  background: var(--blue);
  color: var(--white);
  font-size: 20px;
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(11, 99, 229, 0.4);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: var(--transition);
  z-index: 90;
}
.back-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.back-top:hover { background: var(--blue-dark); }

/* ---------- 滚动入场动画 ---------- */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* =========================================================
   响应式
   ========================================================= */
@media (max-width: 1024px) {
  .hero h1 { font-size: 36px; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-5 { grid-template-columns: repeat(2, 1fr); }
  .stats-list { grid-template-columns: repeat(3, 1fr); row-gap: 28px; }
  .tab-panel { grid-template-columns: 1fr; gap: 28px; padding: 28px; }
  .teacher-grid { grid-template-columns: repeat(2, 1fr); }
  .teacher-slide { flex-basis: calc((100% - 48px) / 3); }
  .kb-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .review-card { flex-basis: 47%; }
}

@media (max-width: 768px) {
  .header-inner { height: 64px; gap: 12px; }
  .header-cta { display: none; }
  .nav-toggle { display: flex; }
  .main-nav {
    position: absolute;
    top: 64px; left: 0; right: 0;
    background: var(--white);
    border-bottom: 1px solid var(--border);
    box-shadow: 0 12px 24px rgba(10,37,64,0.1);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease;
  }
  .main-nav.open { max-height: 400px; }
  .main-nav ul { flex-direction: column; gap: 0; padding: 8px 16px 16px; }
  .main-nav a { padding: 12px 16px; border-radius: 8px; }
  .nav-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav-toggle.active span:nth-child(2) { opacity: 0; }
  .nav-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

  .hero { padding-top: 48px; }
  .hero-inner { grid-template-columns: 1fr; gap: 36px; }
  .hero h1 { font-size: 30px; }
  .hero-sub { font-size: 14px; }
  .section { padding: 30px 0; }
  .section-head h2 { font-size: 25px; }
  .grid-3 { grid-template-columns: 1fr; }
  .stats-bar { padding: 26px 20px 30px; }
  .stats-list { grid-template-columns: repeat(2, 1fr); row-gap: 16px; }
  #home.hero-home .stats-list > li:last-child:nth-child(odd) {
    grid-column: 1 / -1;
    justify-self: center;
    width: calc((100% - 20px) / 2);
  }
  .stats-list strong { font-size: 26px; }
  .kb-card { grid-template-columns: 1fr; }
  .kb-card img { aspect-ratio: 16/9; }
  .review-card { flex-basis: 85%; padding: 24px 20px; }
  .review-summary { flex-direction: column; align-items: flex-start; }
  .teacher-grid { grid-template-columns: 1fr; }
  .teacher-slide { flex-basis: calc((100% - 24px) / 2); }
  .teacher-title { font-size: 23px; }
  .career-arrow { transform: rotate(90deg); }
  .career-path { flex-direction: column; align-items: center; }
  .career-path li:not(.career-arrow) { width: 100%; max-width: 320px; }
  .formula { font-size: 15px; border-radius: var(--radius); }
  .cta-inner h2 { font-size: 26px; }
}

@media (max-width: 480px) {
  .container { padding: 0 26px; }
  .hero h1 { font-size: 26px; }
  .grid-4 { grid-template-columns: 1fr; }
  .grid-5 { grid-template-columns: 1fr; }
  .check-list.cols-2 { grid-template-columns: 1fr; }
  .stats-list { grid-template-columns: 1fr 1fr; }
  .tab-btn { padding: 10px 18px; font-size: 14px; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .teacher-slide { flex-basis: 100%; }
  .teacher-bar p { white-space: normal; }
  .hero-actions { gap: 10px; flex-wrap: wrap; }
  .hero-actions .btn {
    flex: 0 0 auto;
    width: auto;
    min-width: 0;
    padding: 12px 8px;
    font-size: 14px;
    line-height: 1.35;
    text-align: center;
    white-space: nowrap;
  }
}

@media (max-width: 360px) {
  .hero-actions { gap: 8px; }
  .hero-actions .btn {
    padding: 11px 6px;
    font-size: 13px;
  }
}

/* ---------- 小屏：教师内容限宽、两列能力清单 ---------- */
@media (max-width: 560px) {
  #home.hero-home {
    padding-top: 32px;
  }

  #home.hero-home .hero-inner {
    gap: 24px;
  }

  #home.hero-home h1 {
    margin-bottom: 12px;
  }

  #home.hero-home .hero-sub {
    margin-bottom: 20px;
    font-size: 13px;
    line-height: 1.55;
  }

  #home.hero-home .hero-actions {
    gap: 8px 10px;
    margin-bottom: 18px;
  }

  #home.hero-home .hero-points {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px 16px;
  }

  .teacher-carousel {
    max-width: 300px;
    margin-left: auto;
    margin-right: auto;
  }

  .teacher-slide {
    flex-basis: 100%;
  }

  .teacher-photo img {
    aspect-ratio: 4 / 3;
  }

  .teacher-bar {
    padding: 10px 8px 12px;
  }

  .teacher-bar p {
    font-size: 12px;
    line-height: 1.55;
    white-space: normal;
  }

  .teacher-tag {
    right: 8px;
    font-size: 13px;
    letter-spacing: 2px;
    padding: 8px 10px;
  }

  .teacher-nav {
    margin-top: 20px;
    gap: 16px;
  }

  .check-list.cols-2 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 6px 10px;
  }

  .check-list.cols-2 li {
    padding-left: 18px;
    font-size: 13px;
    line-height: 1.55;
  }
}

/* 400–560：Hero 清单两列，减少左侧纵向体量 */
@media (min-width: 400px) and (max-width: 560px) {
  #home.hero-home .hero-sub-list {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 4px 14px;
    padding-left: 1.1em;
  }
}

/* ---------- 导航下拉子菜单（课程介绍） ---------- */
.nav-dropdown { position: relative; }
.nav-dropdown-toggle {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 8px 16px;
  font-size: 15px;
  font-family: inherit;
  line-height: inherit; /* 与导航链接行高一致，保证同一水平线 */
  color: var(--text);
  background: none;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: var(--transition);
}
.nav-dropdown-toggle:hover,
.nav-dropdown.open .nav-dropdown-toggle { color: var(--blue); background: var(--blue-light); }
.nav-caret { font-size: 11px; transition: transform 0.25s ease; }
.nav-dropdown.open .nav-caret { transform: rotate(180deg); }
/* 注：必须用 .nav-dropdown .nav-submenu 提高优先级，
   否则 .main-nav ul 的 display:flex 会覆盖 display:none 导致子菜单常显 */
.nav-dropdown .nav-submenu {
  position: absolute;
  top: calc(100% + 6px);
  left: 50%;
  transform: translateX(-50%);
  min-width: 150px;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 10px;
  box-shadow: 0 16px 36px rgba(10, 37, 64, 0.14);
  padding: 8px;
  display: none;
  z-index: 120;
}
.nav-dropdown.open .nav-submenu { display: block; }
/* 透明桥接区：填充导航与子菜单之间的间隙，避免悬停划过时误收起 */
.nav-dropdown.open .nav-submenu::before {
  content: "";
  position: absolute;
  top: -8px;
  left: 0;
  right: 0;
  height: 8px;
}
.nav-submenu a {
  display: block;
  padding: 10px 14px;
  font-size: 14px;
  color: var(--text);
  border-radius: 8px;
  white-space: nowrap;
}
.nav-submenu a:hover { color: var(--blue); background: var(--blue-light); }
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.nav-toggle span {
  width: 24px; height: 2px;
  background: var(--blue-deep);
  border-radius: 2px;
  transition: var(--transition);
}