/* ==========================================================
   鲲鹏AI · 首页（课程平台首页）
   ========================================================== */

/* ---------- 顶部导航 ---------- */
.app-nav { display: flex; align-items: center; gap: 30px; }
.app-nav a {
  font-size: 15px; color: #4e5969; position: relative;
  padding: 4px 0; transition: color .2s;
}
.app-nav a:hover { color: var(--blue); }
.app-nav a.is-active { color: var(--blue); font-weight: 600; }
.app-nav a.is-active::after {
  content: ""; position: absolute; left: 50%; bottom: -14px; margin-left: -9px;
  width: 18px; height: 2px; background: var(--blue); border-radius: 2px;
}

/* ---------- Banner ---------- */
.hero {
  background: #0e1524;
  padding: 64px 0 40px;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(ellipse 60% 80% at 20% 10%, rgba(31,118,243,.28), transparent 60%),
    radial-gradient(ellipse 50% 70% at 85% 70%, rgba(122,60,255,.24), transparent 60%);
}
.hero-inner { position: relative; z-index: 2; }

.hero-slide {
  display: none;
  border-radius: 16px;
  padding: 52px 56px;
  color: #fff;
  position: relative;
  overflow: hidden;
  min-height: 300px;
  flex-direction: column; justify-content: center;
}
.hero-slide.is-active { display: flex; animation: heroIn .5s ease; }
@keyframes heroIn { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }

.hero-tag {
  display: inline-block; align-self: flex-start;
  background: rgba(255,255,255,.16);
  padding: 5px 12px; border-radius: 14px;
  font-size: 13px; margin-bottom: 18px;
  backdrop-filter: blur(4px);
}
.hero-slide h2 {
  font-size: 40px; font-weight: 700; margin: 0 0 16px;
  line-height: 1.25; max-width: 640px;
}
.hero-slide p {
  font-size: 17px; margin: 0 0 30px;
  opacity: .88; max-width: 560px; line-height: 1.8;
}
.hero-btn {
  display: inline-flex; align-items: center; gap: 8px;
  background: #fff; color: #1f2329;
  height: 46px; padding: 0 30px; border-radius: 23px;
  font-size: 16px; font-weight: 600; width: fit-content;
  transition: transform .2s, box-shadow .2s;
}
.hero-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.22); }
.hero-btn.is-ghost { background: rgba(255,255,255,.14); color: #fff; backdrop-filter: blur(4px); }

/* 装饰图形 */
.hero-deco {
  position: absolute; right: 60px; top: 50%; transform: translateY(-50%);
  width: 260px; height: 200px; opacity: .16; pointer-events: none;
}
.hero-slide::after {
  content: ""; position: absolute; right: -60px; bottom: -80px;
  width: 280px; height: 280px; border-radius: 50%;
  background: rgba(255,255,255,.07);
}

.hero-dots { display: flex; justify-content: center; gap: 8px; margin-top: 24px; }
.hero-dot {
  width: 28px; height: 4px; border-radius: 2px;
  background: rgba(255,255,255,.25); cursor: pointer; transition: background .2s;
}
.hero-dot.is-active { background: rgba(255,255,255,.85); }

/* ---------- 数据条 ---------- */
.stats { background: #fff; border-bottom: 1px solid var(--line); }
.stats-row { display: flex; padding: 30px 0; }
.stat-item { flex: 1; text-align: center; }
.stat-item b { display: block; font-size: 30px; font-weight: 700; color: #1f2329; line-height: 1.2; }
.stat-item span { font-size: 14px; color: var(--text-sub); }
.stat-item + .stat-item { border-left: 1px solid var(--line); }

/* ---------- 通用区块 ---------- */
.section { padding: 56px 0; }
.section--gray { background: #f7f8fa; }
.section--dark { background: #1b2026; color: #fff; }
.sec-head {
  display: flex; align-items: baseline; justify-content: space-between;
  gap: 20px; margin-bottom: 28px; flex-wrap: wrap;
}
.sec-title { font-size: 26px; font-weight: 700; margin: 0; color: #1f2329; }
.section--dark .sec-title { color: #fff; }
.sec-desc { font-size: 14px; color: var(--text-sub); }
.sec-more { font-size: 14px; color: var(--blue); }

/* ---------- 分类卡片 ---------- */
.cat-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.cat-card {
  background: #fff; border: 1px solid var(--line); border-radius: 12px;
  padding: 26px 24px; cursor: pointer;
  transition: transform .2s, box-shadow .2s, border-color .2s;
  position: relative; overflow: hidden;
}
.cat-card:hover { transform: translateY(-3px); box-shadow: 0 10px 28px rgba(0,0,0,.08); border-color: transparent; }
.cat-card__ico {
  width: 44px; height: 44px; border-radius: 11px;
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; color: #fff; margin-bottom: 16px;
}
.cat-card h3 { font-size: 17px; margin: 0 0 8px; color: #1f2329; }
.cat-card p { font-size: 13px; color: var(--text-sub); margin: 0; line-height: 1.7; }
.cat-card__count { margin-top: 16px; font-size: 13px; color: var(--blue); font-weight: 600; }

/* ---------- 课程筛选 ---------- */
.cat-filter { display: flex; gap: 8px; flex-wrap: wrap; }
.filter-chip {
  padding: 7px 16px; border-radius: 16px; font-size: 14px;
  background: #f2f3f5; color: #4e5969; cursor: pointer;
  transition: background .2s, color .2s;
}
.filter-chip:hover { background: #e8eaee; }
.filter-chip.is-active { background: var(--blue); color: #fff; }
.section--gray .filter-chip { background: #e9ebef; }

/* ---------- 课程卡片 ---------- */
.course-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.course-card {
  background: #fff; border-radius: 12px; overflow: hidden;
  cursor: pointer; display: flex; flex-direction: column;
  box-shadow: 0 1px 3px rgba(0,0,0,.06);
  transition: transform .22s, box-shadow .22s;
}
.course-card:hover { transform: translateY(-4px); box-shadow: 0 12px 30px rgba(0,0,0,.1); }
.course-card__cover {
  aspect-ratio: 16/9; position: relative;
  display: flex; align-items: flex-end; padding: 14px;
}
.course-card__tags { display: flex; gap: 6px; }
.course-card__tag {
  font-size: 11px; padding: 3px 8px; border-radius: 3px;
  background: rgba(255,255,255,.9); color: #1f2329; font-weight: 600;
}
.course-card__play {
  position: absolute; right: 12px; bottom: 12px;
  width: 34px; height: 34px; border-radius: 50%;
  background: rgba(0,0,0,.35); backdrop-filter: blur(3px);
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-size: 12px;
}
.course-card__body { padding: 16px 16px 18px; flex: 1; display: flex; flex-direction: column; }
.course-card__name { font-size: 16px; font-weight: 600; color: #1f2329; margin: 0 0 6px; line-height: 1.5; }
.course-card__sub { font-size: 13px; color: var(--text-sub); margin: 0 0 14px; }
.course-card__meta {
  margin-top: auto; display: flex; align-items: center; gap: 12px;
  font-size: 12px; color: var(--text-sub);
}
.course-card__meta em { font-style: normal; color: #ff8f1f; font-weight: 600; }
.course-card__bar { height: 3px; background: #eef0f3; border-radius: 2px; margin-top: 10px; }
.course-card__bar i { display: block; height: 100%; border-radius: 2px; background: var(--blue); }

/* ---------- 学习路径 ---------- */
.path-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 16px; }
.path-card {
  background: #fff; border: 1px solid var(--line); border-radius: 12px;
  padding: 24px 20px; position: relative;
  transition: transform .2s, box-shadow .2s;
}
.path-card:hover { transform: translateY(-3px); box-shadow: 0 10px 26px rgba(0,0,0,.07); }
.path-card__step {
  font-size: 26px; font-weight: 700; color: #c9d4e4;
  line-height: 1; margin-bottom: 14px;
}
.path-card h3 { font-size: 16px; margin: 0 0 10px; color: #1f2329; }
.path-card p { font-size: 13px; color: var(--text-sub); line-height: 1.75; margin: 0 0 12px; }
.path-card__hours { font-size: 12px; color: var(--blue); font-weight: 600; }
.path-card::after {
  content: "→"; position: absolute; right: -14px; top: 50%;
  transform: translateY(-50%); color: #d0d5dd; font-size: 18px; z-index: 3;
}
.path-card:last-child::after { display: none; }

/* ---------- 优势 ---------- */
.adv-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.adv-card {
  background: rgba(255,255,255,.05);
  border: 1px solid rgba(255,255,255,.08);
  border-radius: 12px; padding: 28px 24px;
  transition: background .2s;
}
.adv-card:hover { background: rgba(255,255,255,.09); }
.adv-ico {
  width: 40px; height: 40px; border-radius: 10px;
  background: linear-gradient(135deg, #1f76f3, #6a3ff0);
  display: flex; align-items: center; justify-content: center;
  font-size: 18px; color: #fff; margin-bottom: 16px;
}
.adv-card h3 { font-size: 16px; margin: 0 0 10px; color: #fff; }
.adv-card p { font-size: 13px; color: #9aa3ae; line-height: 1.8; margin: 0; }

/* ---------- 工具 ---------- */
.tool-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 16px; }
.tool-card {
  background: #fff; border: 1px solid var(--line); border-radius: 10px;
  padding: 20px 18px; cursor: pointer;
  transition: transform .2s, box-shadow .2s;
}
.tool-card:hover { transform: translateY(-3px); box-shadow: 0 8px 22px rgba(0,0,0,.07); }
.tool-card__ico {
  width: 38px; height: 38px; border-radius: 9px; background: #f2f6ff;
  display: flex; align-items: center; justify-content: center;
  font-size: 17px; margin-bottom: 12px;
}
.tool-card h4 { font-size: 14px; margin: 0 0 6px; color: #1f2329; font-weight: 600; }
.tool-card p { font-size: 12px; color: var(--text-sub); margin: 0; line-height: 1.6; }
.tool-card__cat {
  display: inline-block; margin-top: 10px; font-size: 11px;
  color: var(--blue); background: #f2f6ff; padding: 2px 7px; border-radius: 3px;
}

/* ---------- 学员作品 ---------- */
.work-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.work-card {
  border-radius: 12px; overflow: hidden; cursor: pointer;
  background: #1b2026; position: relative;
  transition: transform .22s, box-shadow .22s;
}
.work-card:hover { transform: translateY(-4px); box-shadow: 0 14px 32px rgba(0,0,0,.16); }
.work-card__thumb { aspect-ratio: 16/10; display: flex; align-items: center; justify-content: center; }
.work-card__play {
  width: 46px; height: 46px; border-radius: 50%;
  background: rgba(255,255,255,.2); backdrop-filter: blur(3px);
  display: flex; align-items: center; justify-content: center;
  color: #fff; transition: background .2s;
}
.work-card:hover .work-card__play { background: rgba(255,255,255,.34); }
.work-card__body { padding: 14px 16px 18px; background: #fff; }
.work-card__title { font-size: 15px; font-weight: 600; color: #1f2329; margin: 0 0 6px; }
.work-card__meta { font-size: 12px; color: var(--text-sub); display: flex; justify-content: space-between; }
.work-card__tag { color: var(--blue); }

/* ---------- CTA ---------- */
.cta { padding: 70px 0; background: #0e1524; position: relative; overflow: hidden; }
.cta::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(ellipse 50% 70% at 25% 20%, rgba(31,118,243,.26), transparent 60%),
    radial-gradient(ellipse 50% 70% at 78% 80%, rgba(122,60,255,.22), transparent 60%);
}
.cta-inner { position: relative; z-index: 2; text-align: center; color: #fff; }
.cta h2 { font-size: 34px; margin: 0 0 14px; font-weight: 700; }
.cta p { font-size: 16px; opacity: .82; margin: 0 0 32px; line-height: 1.8; }
.cta-btns { display: flex; gap: 14px; justify-content: center; }
.btn--lg {
  height: 48px; padding: 0 36px; border-radius: 24px;
  font-size: 16px; font-weight: 600;
}
.btn--line { border: 1px solid rgba(255,255,255,.4); color: #fff; }
.btn--line:hover { background: rgba(255,255,255,.12); }

/* ---------- 继续学习（已购学员入口） ---------- */
.resume-section { padding: 28px 0 0; }
.resume-card {
  background: linear-gradient(120deg, #1b2b6b, #3b1f7a);
  border-radius: 16px; padding: 28px 32px;
  color: #fff; display: flex; align-items: center;
  justify-content: space-between; gap: 28px; position: relative; overflow: hidden;
}
.resume-card::after {
  content: ""; position: absolute; right: -40px; top: -60px;
  width: 220px; height: 220px; border-radius: 50%;
  background: rgba(255,255,255,.06);
}
.resume-card__info { position: relative; z-index: 2; min-width: 0; }
.resume-card__tag {
  display: inline-block; font-size: 12px;
  background: rgba(255,255,255,.16); padding: 3px 10px;
  border-radius: 12px; margin-bottom: 12px;
}
.resume-card__title {
  font-size: 22px; font-weight: 700; margin: 0 0 8px;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.resume-card__meta { font-size: 14px; opacity: .82; margin: 0 0 18px; }
.resume-card__acts { display: flex; gap: 10px; flex-wrap: wrap; }
.resume-card__acts .btn { height: 40px; padding: 0 24px; font-size: 14px; }
.resume-card__acts .btn--ghost {
  background: rgba(255,255,255,.14); color: #fff;
}
.resume-card__acts .btn--ghost:hover { background: rgba(255,255,255,.22); }

.resume-card__stat {
  display: flex; gap: 28px; position: relative; z-index: 2;
  flex-shrink: 0; padding-left: 28px; border-left: 1px solid rgba(255,255,255,.16);
}
.resume-stat { text-align: center; }
.resume-stat b {
  display: block; font-size: 30px; font-weight: 700;
  line-height: 1.2; margin-bottom: 4px;
}
.resume-stat span { font-size: 12px; opacity: .75; }

@media (max-width: 900px) {
  .resume-card { flex-direction: column; align-items: flex-start; padding: 22px 18px; gap: 18px; }
  .resume-card__title { font-size: 18px; white-space: normal; }
  .resume-card__stat { padding-left: 0; border-left: 0; border-top: 1px solid rgba(255,255,255,.16); padding-top: 16px; width: 100%; }
  .resume-stat { flex: 1; }
  .resume-stat b { font-size: 22px; }
  .resume-card__acts { width: 100%; }
  .resume-card__acts .btn { flex: 1; justify-content: center; }
}

/* ---------- 尾部导航 ---------- */
@media (max-width: 1280px) {
  .course-grid { grid-template-columns: repeat(3, 1fr); }
  .tool-grid { grid-template-columns: repeat(4, 1fr); }
  .path-grid { grid-template-columns: repeat(3, 1fr); }
  .path-card::after { display: none; }
}
@media (max-width: 900px) {
  .app-nav { display: none; }
  .cat-grid { grid-template-columns: repeat(2, 1fr); }
  .course-grid { grid-template-columns: repeat(2, 1fr); }
  .adv-grid { grid-template-columns: repeat(2, 1fr); }
  .tool-grid { grid-template-columns: repeat(2, 1fr); }
  .path-grid { grid-template-columns: 1fr; }
  .work-grid { grid-template-columns: repeat(2, 1fr); }
  .hero { padding: 30px 0 24px; }
  .hero-slide { padding: 32px 24px; min-height: auto; }
  .hero-slide h2 { font-size: 26px; }
  .hero-slide p { font-size: 14px; }
  .stats-row { flex-wrap: wrap; }
  .stat-item { flex: 1 0 50%; padding: 14px 0; }
  .stat-item + .stat-item { border-left: 0; }
  .cta h2 { font-size: 24px; }
}