/* ============================================
   黄色仓库在线课程与职业技能培训平台 - 主样式表
   ============================================ */

/* === 基础重置 === */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Inter', 'Roboto', 'Noto Sans SC', 'Helvetica Neue', Arial, sans-serif;
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
  background-color: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Montserrat', 'Noto Sans SC', sans-serif;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
  color: var(--primary);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.1rem; }
h6 { font-size: 1rem; }

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover { color: var(--accent); }

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul, ol { list-style: none; }

/* === 容器 === */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.container--wide {
  max-width: var(--container-wide);
}

/* === 顶部导航栏 === */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--bg);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-normal);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-md) var(--spacing-lg);
  max-width: var(--container-wide);
  margin: 0 auto;
}

.header__logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.header__logo img {
  height: 40px;
  width: auto;
}

.header__logo-text {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
}

.header__search {
  flex: 1;
  max-width: 400px;
  margin: 0 var(--spacing-xl);
  position: relative;
}

.header__search input {
  width: 100%;
  padding: 0.6rem 1rem 0.6rem 2.5rem;
  border: 2px solid var(--card-bg);
  border-radius: 24px;
  font-size: 0.9rem;
  transition: border-color var(--transition-fast);
  outline: none;
}

.header__search input:focus {
  border-color: var(--accent);
}

.header__search-icon {
  position: absolute;
  left: 0.8rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
}

.header__nav {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.header__nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text);
  transition: color var(--transition-fast);
  position: relative;
}

.header__nav-link:hover {
  color: var(--primary);
}

.header__nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: width var(--transition-normal);
}

.header__nav-link:hover::after {
  width: 100%;
}

.header__actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

/* === 按钮 === */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: 0.7rem 1.5rem;
  border: none;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.btn--primary {
  background: var(--primary);
  color: #fff;
}
.btn--primary:hover {
  background: var(--secondary);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn--secondary {
  background: var(--secondary);
  color: #fff;
}
.btn--secondary:hover {
  background: var(--primary);
  color: #fff;
  transform: translateY(-2px);
}

.btn--outline {
  background: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
}
.btn--outline:hover {
  background: var(--primary);
  color: #fff;
}

.btn--accent {
  background: var(--accent);
  color: #fff;
}

.btn--lg {
  padding: 1rem 2rem;
  font-size: 1.1rem;
}

/* === 英雄区 === */
.hero {
  position: relative;
  min-height: 600px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
}

.hero__bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.3;
}

.hero__content {
  position: relative;
  z-index: 2;
  max-width: 650px;
  padding: var(--spacing-3xl) var(--spacing-xl);
  margin-left: 8%;
}

.hero__title {
  font-size: 3rem;
  color: #fff;
  margin-bottom: var(--spacing-lg);
  line-height: 1.15;
}

.hero__subtitle {
  font-size: 1.2rem;
  color: rgba(255,255,255,0.9);
  margin-bottom: var(--spacing-xl);
  line-height: 1.6;
}

.hero__actions {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.hero__stats {
  display: flex;
  gap: var(--spacing-2xl);
  margin-top: var(--spacing-2xl);
}

.hero__stat {
  text-align: center;
  color: #fff;
}

.hero__stat-number {
  font-size: 2rem;
  font-weight: 700;
  display: block;
}

.hero__stat-label {
  font-size: 0.9rem;
  opacity: 0.85;
}

/* === 区块通用 === */
.section {
  padding: var(--spacing-3xl) 0;
}

.section--gray {
  background: #F8FAFE;
}

.section__header {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
}

.section__title {
  font-size: 2rem;
  margin-bottom: var(--spacing-sm);
}

.section__subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto;
}

/* === 课程卡片 === */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--spacing-xl);
}

.course-card {
  background: var(--bg);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
  border: 1px solid #E8F0FE;
}

.course-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.course-card__image {
  position: relative;
  padding-top: 56.25%;
  overflow: hidden;
}

.course-card__image img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-normal);
}

.course-card:hover .course-card__image img {
  transform: scale(1.05);
}

.course-card__badge {
  position: absolute;
  top: var(--spacing-sm);
  left: var(--spacing-sm);
  background: var(--accent);
  color: #fff;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
}

.course-card__body {
  padding: var(--spacing-lg);
}

.course-card__category {
  font-size: 0.8rem;
  color: var(--accent);
  font-weight: 600;
  text-transform: uppercase;
  margin-bottom: var(--spacing-xs);
}

.course-card__title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: var(--spacing-sm);
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.course-card__instructor {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
}

.course-card__instructor img {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-full);
  object-fit: cover;
}

.course-card__instructor-name {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.course-card__meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: var(--spacing-md);
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--card-bg);
}

.course-card__rating {
  display: flex;
  align-items: center;
  gap: 0.2rem;
}

.course-card__rating .stars {
  color: var(--warning);
  font-size: 0.85rem;
}

.course-card__rating .score {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text);
  margin-left: 0.3rem;
}

.course-card__students {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.course-card__price {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--primary);
}

.course-card__price--free {
  color: var(--success);
}

/* === 学习路径 === */
.paths-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: var(--spacing-xl);
}

.path-card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  transition: all var(--transition-normal);
  border: 2px solid transparent;
}

.path-card:hover {
  border-color: var(--primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.path-card__icon {
  width: 60px;
  height: 60px;
  background: var(--primary);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-lg);
  font-size: 1.5rem;
  color: #fff;
}

.path-card__title {
  font-size: 1.2rem;
  color: var(--text);
  margin-bottom: var(--spacing-sm);
}

.path-card__desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: var(--spacing-lg);
  line-height: 1.6;
}

.path-card__meta {
  display: flex;
  gap: var(--spacing-lg);
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* === 讲师卡片 === */
.instructors-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--spacing-xl);
}

.instructor-card {
  text-align: center;
  padding: var(--spacing-xl);
  background: var(--bg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.instructor-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.instructor-card__avatar {
  width: 100px;
  height: 100px;
  border-radius: var(--radius-full);
  object-fit: cover;
  margin: 0 auto var(--spacing-lg);
  border: 3px solid var(--card-bg);
}

.instructor-card__name {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: var(--spacing-xs);
}

.instructor-card__title {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: var(--spacing-md);
}

.instructor-card__stats {
  display: flex;
  justify-content: center;
  gap: var(--spacing-lg);
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* === 评价卡片 === */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--spacing-xl);
}

.testimonial-card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  position: relative;
}

.testimonial-card__quote {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--text);
  margin-bottom: var(--spacing-lg);
  font-style: italic;
}

.testimonial-card__author {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.testimonial-card__avatar {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
  object-fit: cover;
}

.testimonial-card__name {
  font-weight: 600;
  font-size: 0.95rem;
}

.testimonial-card__role {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* === 平台优势 === */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: var(--spacing-xl);
}

.feature-item {
  text-align: center;
  padding: var(--spacing-xl);
}

.feature-item__icon {
  width: 72px;
  height: 72px;
  background: var(--card-bg);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--spacing-lg);
  font-size: 2rem;
  color: var(--primary);
  transition: all var(--transition-normal);
}

.feature-item:hover .feature-item__icon {
  background: var(--primary);
  color: #fff;
  transform: scale(1.1);
}

.feature-item__title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: var(--spacing-sm);
}

.feature-item__desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* === 合作伙伴 === */
.partners {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--spacing-2xl);
  padding: var(--spacing-xl) 0;
}

.partners__logo {
  height: 40px;
  opacity: 0.5;
  filter: grayscale(100%);
  transition: all var(--transition-normal);
}

.partners__logo:hover {
  opacity: 1;
  filter: grayscale(0%);
}

/* === 倒计时组件 === */
.countdown {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
}

.countdown__item {
  text-align: center;
  background: var(--primary);
  color: #fff;
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--radius-md);
  min-width: 70px;
}

.countdown__number {
  font-size: 2rem;
  font-weight: 700;
  font-family: 'Courier New', monospace;
  display: block;
}

.countdown__label {
  font-size: 0.75rem;
  text-transform: uppercase;
  opacity: 0.85;
}

/* === 进度环形图 === */
.progress-ring {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.progress-ring__circle {
  transform: rotate(-90deg);
}

.progress-ring__bg {
  fill: none;
  stroke: var(--card-bg);
  stroke-width: 8;
}

.progress-ring__fill {
  fill: none;
  stroke: var(--accent);
  stroke-width: 8;
  stroke-linecap: round;
  transition: stroke-dashoffset 1s ease;
}

.progress-ring__text {
  position: absolute;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
}

/* === 页脚 === */
.footer {
  background: var(--secondary);
  color: #fff;
  padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1.5fr;
  gap: var(--spacing-2xl);
  margin-bottom: var(--spacing-2xl);
}

.footer__brand p {
  font-size: 0.9rem;
  opacity: 0.8;
  line-height: 1.7;
  margin-top: var(--spacing-md);
}

.footer__title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: var(--spacing-lg);
  color: #fff;
}

.footer__links li {
  margin-bottom: var(--spacing-sm);
}

.footer__links a {
  color: rgba(255,255,255,0.75);
  font-size: 0.9rem;
  transition: color var(--transition-fast);
}

.footer__links a:hover {
  color: #fff;
}

.footer__subscribe {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
}

.footer__subscribe input {
  flex: 1;
  padding: 0.6rem 1rem;
  border: 1px solid rgba(255,255,255,0.3);
  border-radius: var(--radius-md);
  background: rgba(255,255,255,0.1);
  color: #fff;
  font-size: 0.9rem;
  outline: none;
}

.footer__subscribe input::placeholder {
  color: rgba(255,255,255,0.5);
}

.footer__subscribe button {
  padding: 0.6rem 1.2rem;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  font-weight: 600;
  transition: background var(--transition-fast);
}

.footer__subscribe button:hover {
  background: #1E88E5;
}

.footer__bottom {
  border-top: 1px solid rgba(255,255,255,0.15);
  padding-top: var(--spacing-xl);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.footer__copyright {
  font-size: 0.85rem;
  opacity: 0.75;
}

.footer__legal {
  display: flex;
  gap: var(--spacing-lg);
}

.footer__legal a {
  font-size: 0.85rem;
  color: rgba(255,255,255,0.7);
}

.footer__legal a:hover {
  color: #fff;
}

/* === 面包屑导航 === */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.breadcrumb a {
  color: var(--text-muted);
}

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

.breadcrumb__separator {
  color: var(--text-muted);
  opacity: 0.5;
}

/* === 筛选器侧边栏 === */
.sidebar-filter {
  background: var(--bg);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  box-shadow: var(--shadow-sm);
}

.sidebar-filter__group {
  margin-bottom: var(--spacing-xl);
}

.sidebar-filter__title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: var(--spacing-md);
}

.sidebar-filter__item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-xs) 0;
  font-size: 0.9rem;
  color: var(--text-muted);
  cursor: pointer;
}

/* === 分页 === */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-2xl);
}

.pagination__btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  border: 1px solid var(--card-bg);
  color: var(--text);
  font-size: 0.9rem;
  cursor: pointer;
  transition: all var(--transition-fast);
  background: var(--bg);
}

.pagination__btn:hover,
.pagination__btn--active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

/* === 移动端菜单 === */
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 5px;
}

.mobile-menu-btn span {
  width: 24px;
  height: 2px;
  background: var(--text);
  transition: all var(--transition-fast);
}

/* === 动画 === */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* === 骨架屏 === */
.skeleton {
  background: linear-gradient(90deg, var(--card-bg) 25%, #D6E9FC 50%, var(--card-bg) 75%);
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s infinite;
  border-radius: var(--radius-md);
}

@keyframes skeleton-loading {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* === 响应式设计 === */
@media (max-width: 1024px) {
  .header__search {
    max-width: 280px;
  }
  
  .footer__grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .hero__title {
    font-size: 2.5rem;
  }
}

@media (max-width: 768px) {
  .mobile-menu-btn {
    display: flex;
  }
  
  .header__nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg);
    flex-direction: column;
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
  }
  
  .header__nav.active {
    display: flex;
  }
  
  .header__search {
    display: none;
  }
  
  .hero {
    min-height: 450px;
  }
  
  .hero__content {
    margin-left: 0;
    padding: var(--spacing-xl);
    text-align: center;
  }
  
  .hero__title {
    font-size: 2rem;
  }
  
  .hero__actions {
    justify-content: center;
  }
  
  .hero__stats {
    justify-content: center;
  }
  
  .courses-grid {
    grid-template-columns: 1fr;
  }
  
  .paths-grid {
    grid-template-columns: 1fr;
  }
  
  .instructors-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .testimonials-grid {
    grid-template-columns: 1fr;
  }
  
  .footer__grid {
    grid-template-columns: 1fr;
  }
  
  .footer__bottom {
    flex-direction: column;
    text-align: center;
  }
  
  h1 { font-size: 1.8rem; }
  h2 { font-size: 1.5rem; }
  
  .section {
    padding: var(--spacing-2xl) 0;
  }
}

@media (max-width: 480px) {
  .instructors-grid {
    grid-template-columns: 1fr;
  }
  
  .countdown {
    gap: var(--spacing-sm);
  }
  
  .countdown__item {
    min-width: 55px;
    padding: var(--spacing-sm) var(--spacing-md);
  }
  
  .countdown__number {
    font-size: 1.5rem;
  }
}