/* AI Education Website Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --background: #0a0a0a;
  --foreground: #fafafa;
  --primary: #3b82f6;
  --primary-light: #60a5fa;
  --muted: #a1a1aa;
  --card: #18181b;
  --border: #27272a;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--background);
  color: var(--foreground);
  line-height: 1.6;
}

/* Navigation */
.navbar {
  position: static; /* 不再固定顶部 */
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(10, 10, 10, 0.8);
  backdrop-filter: blur(12px);
  z-index: 1000;
  border-bottom: 1px solid var(--border);
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--foreground);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* 修复 logo 背景透明 & 大小显示正确 */
.logo-icon {
  width: 36px;            /* Logo 显示大小，可调整 */
  height: 36px;
  border-radius: 6px;
  overflow: hidden;
  background: transparent !important;  /* 关键！彻底移除蓝色背景 */
  display: flex;
  align-items: center;
  justify-content: center;
}

.logo-icon img {
  width: 100%;
  height: 100%;
  object-fit: contain;    /* 不裁切，不变形 */
}

/* Logo + 文字水平对齐 */
.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.3s;
}

.nav-links a:hover {
  color: var(--foreground);
}

.nav-buttons {
  display: flex;
  gap: 1rem;
  align-items: center;
}

.btn {
  padding: 0.6rem 1.25rem;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s;
  text-decoration: none;
}

.btn-ghost {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--foreground);
}

.btn-ghost:hover {
  background: var(--card);
}

.btn-primary {
  background: var(--foreground);
  border: none;
  color: var(--background);
}

.btn-primary:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--foreground);
}

.btn-outline:hover {
  background: var(--card);
}

.btn-large {
  padding: 0.875rem 1.75rem;
  font-size: 1rem;
}

/* Hero Section */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 8rem 2rem 4rem;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -50%;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.15) 0%, transparent 70%);
  pointer-events: none;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 50px;
  font-size: 0.875rem;
  color: var(--primary-light);
  margin-bottom: 2rem;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 700;
  line-height: 1.1;
  max-width: 900px;
  margin-bottom: 1.5rem;
  letter-spacing: -0.02em;
}

.hero p {
  font-size: 1.25rem;
  color: var(--muted);
  max-width: 600px;
  margin-bottom: 2.5rem;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  justify-content: center;
}

/* 添加Hero图片样式 */
.hero-image {
  margin-top: 3rem;
  max-width: 800px;
  width: 100%;
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
}

.hero-image img {
  width: 100%;
  height: auto;
  display: block;
}

/* Trusted By Section */
.trusted-by {
  padding: 4rem 2rem;
  text-align: center;
  border-top: 1px solid var(--border);
}

.trusted-by p {
  color: var(--muted);
  font-size: 0.875rem;
  margin-bottom: 2rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.trusted-logos {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 3rem;
  flex-wrap: wrap;
  opacity: 0.6;
}

.trusted-logos span {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--muted);
}

/* Features Section */
.features {
  padding: 6rem 2rem;
  max-width: 1200px;
  margin: 0 auto;
}

.section-header {
  text-align: center;
  margin-bottom: 4rem;
}

.section-header h2 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.section-header p {
  color: var(--muted);
  font-size: 1.125rem;
  max-width: 600px;
  margin: 0 auto;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.feature-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 2rem;
  transition: all 0.3s;
}

.feature-card:hover {
  border-color: var(--primary);
  transform: translateY(-4px);
}

/* 更新功能图标样式以支持图片 */
.feature-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
  font-size: 1.5rem;
  overflow: hidden;
}

.feature-icon img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

.feature-card p {
  color: var(--muted);
  font-size: 0.95rem;
}

/* Courses Section */
.courses {
  padding: 6rem 2rem;
  background: var(--card);
}

.courses-container {
  max-width: 1200px;
  margin: 0 auto;
}

/* 课程分类标签样式 */
.course-categories {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
}

.category-btn {
  padding: 0.625rem 1.25rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 50px;
  color: var(--muted);
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.3s;
}

.category-btn:hover {
  border-color: var(--primary);
  color: var(--foreground);
}

.category-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
}

/* 增强课程卡片样式 */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 1.75rem;
}

.course-card {
  background: var(--background);
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  transition: all 0.3s;
}

.course-card:hover {
  border-color: var(--primary);
  transform: translateY(-6px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.course-image {
  height: 180px;
  background: linear-gradient(135deg, #1e3a5f, #0f172a);
  position: relative;
  overflow: hidden;
}

.course-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s;
}

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

.course-badge {
  position: absolute;
  top: 12px;
  left: 12px;
  padding: 0.25rem 0.75rem;
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 600;
}

.course-badge.hot {
  background: #ef4444;
  color: white;
}

.course-badge.new {
  background: #22c55e;
  color: white;
}

.course-badge.live {
  background: #f97316;
  color: white;
}

.course-badge.free {
  background: var(--primary);
  color: white;
}

.course-play-btn {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 56px;
  height: 56px;
  background: rgba(0, 0, 0, 0.6);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: all 0.3s;
}

.course-card:hover .course-play-btn {
  opacity: 1;
}

.course-play-btn:hover {
  background: var(--primary);
  transform: translate(-50%, -50%) scale(1.1);
}

.course-content {
  padding: 1.25rem;
}

.course-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.75rem;
}

.course-tag {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  background: rgba(59, 130, 246, 0.15);
  color: var(--primary-light);
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 500;
}

.course-tag.coding {
  background: rgba(34, 197, 94, 0.15);
  color: #4ade80;
}

.course-tag.data {
  background: rgba(168, 85, 247, 0.15);
  color: #c084fc;
}

.course-tag.design {
  background: rgba(236, 72, 153, 0.15);
  color: #f472b6;
}

.course-tag.business {
  background: rgba(251, 191, 36, 0.15);
  color: #fbbf24;
}

.course-price {
  font-size: 1.125rem;
  font-weight: 700;
  color: #ef4444;
}

.course-price.free {
  color: #22c55e;
}

.course-content h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  line-height: 1.4;
}

.course-content > p {
  color: var(--muted);
  font-size: 0.875rem;
  margin-bottom: 1rem;
  line-height: 1.5;
}

.course-instructor {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border);
}

.course-instructor img {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  object-fit: cover;
}

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

.course-meta {
  display: flex;
  gap: 1rem;
  color: var(--muted);
  font-size: 0.8rem;
  margin-bottom: 1rem;
}

.course-meta span {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.course-actions {
  display: flex;
  gap: 0.75rem;
}

.btn-enroll {
  flex: 1;
  padding: 0.75rem 1rem;
  background: var(--primary);
  border: none;
  border-radius: 8px;
  color: white;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s;
}

.btn-enroll:hover {
  background: var(--primary-light);
}

.btn-favorite {
  width: 44px;
  height: 44px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s;
  color: var(--muted);
}

.btn-favorite:hover {
  border-color: #ef4444;
  color: #ef4444;
}

.courses-more {
  text-align: center;
  margin-top: 3rem;
}

.courses-more .btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

/* Stats Section */
.stats {
  padding: 6rem 2rem;
  max-width: 1200px;
  margin: 0 auto;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  text-align: center;
}

.stat-item h3 {
  font-size: 3rem;
  font-weight: 700;
  color: var(--primary-light);
  margin-bottom: 0.5rem;
}

.stat-item p {
  color: var(--muted);
  font-size: 1rem;
}

/* Testimonials Section */
.testimonials {
  padding: 6rem 2rem;
  background: var(--card);
}

.testimonials-container {
  max-width: 1200px;
  margin: 0 auto;
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.testimonial-card {
  background: var(--background);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 2rem;
}

.testimonial-card p {
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 1.5rem;
  color: var(--muted);
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* 更新用户头像样式以支持图片 */
.author-avatar {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  overflow: hidden;
}

.author-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.author-info h4 {
  font-size: 1rem;
  font-weight: 600;
}

.author-info span {
  font-size: 0.875rem;
  color: var(--muted);
}

/* CTA Section */
.cta {
  padding: 6rem 2rem;
  text-align: center;
}

.cta-container {
  max-width: 800px;
  margin: 0 auto;
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), transparent);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 4rem 2rem;
}

.cta h2 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.cta p {
  color: var(--muted);
  font-size: 1.125rem;
  margin-bottom: 2rem;
}

/* Footer */
.footer {
  padding: 4rem 2rem 2rem;
  border-top: 1px solid var(--border);
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-brand p {
  color: var(--muted);
  font-size: 0.95rem;
  margin-top: 1rem;
  max-width: 300px;
}

.footer-links h4 {
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-links ul {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.75rem;
}

.footer-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.3s;
}

.footer-links a:hover {
  color: var(--foreground);
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-bottom p {
  color: var(--muted);
  font-size: 0.875rem;
}

.footer-social {
  display: flex;
  gap: 1rem;
}

.footer-social a {
  width: 40px;
  height: 40px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  text-decoration: none;
  transition: all 0.3s;
}

.footer-social a:hover {
  background: var(--primary);
  color: var(--foreground);
  border-color: var(--primary);
}

/* Mobile Menu */
.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--foreground);
  font-size: 1.5rem;
  cursor: pointer;
}

/* Responsive */
@media (max-width: 768px) {
  .nav-links,
  .nav-buttons {
    display: none;
  }

  .mobile-menu-btn {
    display: block;
  }

  .mobile-menu {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--background);
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
    z-index: 2000;
    transform: translateX(100%);
    transition: transform 0.3s;
  }

  .mobile-menu.active {
    transform: translateX(0);
  }

  .mobile-menu-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
  }

  .mobile-menu-close {
    background: none;
    border: none;
    color: var(--foreground);
    font-size: 1.5rem;
    cursor: pointer;
  }

  .mobile-menu-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
  }

  .mobile-menu-links a {
    color: var(--foreground);
    text-decoration: none;
    font-size: 1.25rem;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .hero h1 {
    font-size: 2rem;
  }
}

/* 平台功能区域样式 */
.platform-features {
  padding: 6rem 2rem;
  max-width: 1200px;
  margin: 0 auto;
}

.platform-container {
  max-width: 1200px;
  margin: 0 auto;
}

.platform-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.75rem;
}

.platform-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 2rem;
  position: relative;
  transition: all 0.3s;
}

.platform-card:hover {
  border-color: var(--primary);
  transform: translateY(-4px);
}

.platform-card.featured {
  border-color: var(--primary);
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), transparent);
}

.platform-badge {
  position: absolute;
  top: -10px;
  right: 20px;
  padding: 0.35rem 1rem;
  background: var(--primary);
  color: white;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 50px;
}

.platform-icon {
  width: 64px;
  height: 64px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
}

.platform-icon.video {
  background: linear-gradient(135deg, #ef4444, #f97316);
}

.platform-icon.reward {
  background: linear-gradient(135deg, #fbbf24, #f59e0b);
}

.platform-icon.shop {
  background: linear-gradient(135deg, #22c55e, #10b981);
}

.platform-card h3 {
  font-size: 1.35rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

.platform-card > p {
  color: var(--muted);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
  line-height: 1.5;
}

.platform-list {
  list-style: none;
  margin-bottom: 1.5rem;
}

.platform-list li {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.5rem 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.check-icon {
  color: var(--primary-light);
  font-weight: 600;
}

.platform-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--primary-light);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: all 0.3s;
}

.platform-link:hover {
  color: var(--foreground);
  gap: 0.75rem;
}

/* 个人中心区域样式 */
.user-center {
  padding: 6rem 2rem;
  background: var(--card);
}

.user-container {
  max-width: 1200px;
  margin: 0 auto;
}

.user-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.user-badge {
  display: inline-block;
  padding: 0.5rem 1rem;
  background: rgba(59, 130, 246, 0.15);
  color: var(--primary-light);
  border-radius: 50px;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 1rem;
}

.user-text h2 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.user-text > p {
  color: var(--muted);
  font-size: 1.125rem;
  margin-bottom: 2rem;
}

.user-features {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.user-feature {
  display: flex;
  gap: 1rem;
}

.user-feature-icon {
  width: 48px;
  height: 48px;
  background: var(--background);
  border: 1px solid var(--border);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--primary-light);
}

.user-feature h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.user-feature p {
  font-size: 0.85rem;
  color: var(--muted);
}

.user-image {
  position: relative;
}

.user-image img {
  width: 100%;
  max-width: 400px;
  border-radius: 24px;
  border: 1px solid var(--border);
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
}

/* 响应式适配 */
@media (max-width: 768px) {
  .course-categories {
    gap: 0.5rem;
  }

  .category-btn {
    padding: 0.5rem 1rem;
    font-size: 0.8rem;
  }

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

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

  .user-content {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .user-features {
    grid-template-columns: 1fr;
  }

  .user-text h2 {
    font-size: 2rem;
  }

  .user-image {
    order: -1;
  }
}

/* 新增海量题库板块样式 */
/* Question Bank Section */
.question-bank {
  padding: 6rem 2rem;
  background: var(--card);
}

.question-bank-container {
  max-width: 1200px;
  margin: 0 auto;
}

/* 题库统计数据 */
.bank-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  margin-bottom: 3rem;
  padding: 2rem;
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), transparent);
  border: 1px solid var(--border);
  border-radius: 16px; /* Added from update */
}

.bank-stat-item {
  text-align: center;
}

.bank-stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--primary-light);
  margin-bottom: 0.25rem;
}

.bank-stat-label {
  color: var(--muted);
  font-size: 0.95rem;
}

/* 学段分类标签 */
.grade-categories {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.grade-btn {
  padding: 0.625rem 1.25rem;
  background: var(--background);
  border: 1px solid var(--border);
  border-radius: 50px;
  color: var(--muted);
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.3s;
}

.grade-btn:hover {
  border-color: var(--primary);
  color: var(--foreground);
}

.grade-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
}

/* 列表式学科布局 */
.subjects-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.subject-item {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 1.25rem 1.5rem;
  background: var(--background);
  border: 1px solid var(--border);
  border-radius: 12px;
  transition: all 0.3s;
}

.subject-item:hover {
  border-color: var(--primary);
  transform: translateX(4px);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

.subject-item .subject-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: white;
}

.subject-icon.chinese {
  background: linear-gradient(135deg, #ef4444, #f97316);
}
.subject-icon.math {
  background: linear-gradient(135deg, #3b82f6, #60a5fa);
}
.subject-icon.english {
  background: linear-gradient(135deg, #22c55e, #4ade80);
}
.subject-icon.physics {
  background: linear-gradient(135deg, #8b5cf6, #a78bfa);
}
.subject-icon.chemistry {
  background: linear-gradient(135deg, #ec4899, #f472b6);
}
.subject-icon.biology {
  background: linear-gradient(135deg, #14b8a6, #2dd4bf);
}
.subject-icon.history {
  background: linear-gradient(135deg, #f59e0b, #fbbf24);
}
.subject-icon.geography {
  background: linear-gradient(135deg, #06b6d4, #22d3ee);
}
.subject-icon.politics {
  background: linear-gradient(135deg, #ef4444, #dc2626);
}

.subject-info {
  flex: 1;
  min-width: 0;
}

.subject-info h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
  color: var(--foreground);
}

.subject-info p {
  font-size: 0.875rem;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.subject-item .subject-grades {
  display: flex;
  gap: 0.5rem;
  flex-shrink: 0;
}

.grade-tag {
  padding: 0.25rem 0.625rem;
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 500;
}

.grade-tag.primary {
  background: rgba(59, 130, 246, 0.15);
  color: #60a5fa;
}

.grade-tag.junior {
  background: rgba(34, 197, 94, 0.15);
  color: #4ade80;
}

.grade-tag.senior {
  background: rgba(168, 85, 247, 0.15);
  color: #c084fc;
}

.subject-count {
  font-size: 0.9rem;
  color: var(--primary-light);
  font-weight: 600;
  flex-shrink: 0;
  min-width: 100px;
  text-align: right;
}

/* 题库特色功能 */
.bank-features {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  margin-top: 3rem;
  margin-bottom: 2rem;
}

.bank-feature-item {
  text-align: center;
  padding: 1.5rem;
  background: var(--background);
  border: 1px solid var(--border);
  border-radius: 12px;
  transition: all 0.3s;
}

.bank-feature-item:hover {
  border-color: var(--primary);
}

.bank-feature-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  color: white;
}

.bank-feature-item h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.bank-feature-item p {
  font-size: 0.85rem;
  color: var(--muted);
}

.bank-more {
  text-align: center;
  margin-top: 2rem;
  display: flex;
  justify-content: center;
  gap: 1rem;
}

/* 响应式适配 */
@media (max-width: 992px) {
  .bank-stats {
    grid-template-columns: repeat(2, 1fr);
  }

  .bank-features {
    grid-template-columns: repeat(2, 1fr);
  }

  .subject-item {
    flex-wrap: wrap;
  }

  .subject-info {
    flex: 1 1 200px;
  }

  .subject-grades {
    order: 5;
    width: 100%;
    margin-top: 0.5rem;
  }

  .subject-count {
    text-align: left;
  }
}

@media (max-width: 768px) {
  .bank-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    padding: 1.5rem;
  }

  .bank-stat-number {
    font-size: 1.75rem;
  }

  .grade-categories {
    gap: 0.5rem;
  }

  .grade-btn {
    padding: 0.5rem 1rem;
    font-size: 0.8rem;
  }

  .subject-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
    padding: 1.25rem;
  }

  .subject-item .subject-icon {
    width: 40px;
    height: 40px;
  }

  .subject-count {
    text-align: left;
    min-width: auto;
  }

  .bank-features {
    grid-template-columns: 1fr;
  }

  .bank-more {
    flex-direction: column;
  }

  .bank-more .btn {
    width: 100%;
  }
}


.logo-icon {
  width: 36px;
  height: 36px;
  border-radius: 6px;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}
.logo-icon img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}
.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}