/* 工业刀具学习笔记 - 全局样式 */
:root {
  --color-bg: #f5f6f8;
  --color-white: #ffffff;
  --color-text: #2c3e50;
  --color-text-light: #5a6a7e;
  --color-border: #e2e6ea;
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-dark: #1e293b;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --radius: 8px;
  --max-width: 1100px;
}

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

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s;
}

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

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

/* 头部导航 */
.site-header {
  background: var(--color-dark);
  color: var(--color-white);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-md);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.site-logo {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-white);
  letter-spacing: 0.5px;
}

.site-logo:hover {
  color: #93c5fd;
}

.site-nav {
  display: flex;
  gap: 6px;
  list-style: none;
}

.site-nav a {
  color: #cbd5e1;
  padding: 8px 14px;
  border-radius: 4px;
  font-size: 0.9rem;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--color-white);
  background: rgba(255, 255, 255, 0.1);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-white);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 4px 8px;
}

/* 主内容区 */
.main-content {
  flex: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 32px 20px 48px;
  width: 100%;
}

/* 页脚 */
.site-footer {
  background: var(--color-dark);
  color: #94a3b8;
  padding: 28px 20px;
  font-size: 0.85rem;
  text-align: center;
}

.site-footer a {
  color: #93c5fd;
}

.footer-links {
  margin-bottom: 10px;
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
}

.site-footer p + p {
  margin-top: 6px;
}

/* 页面标题区 */
.page-hero {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px 28px;
  margin-bottom: 28px;
  box-shadow: var(--shadow-sm);
}

.page-hero h1 {
  font-size: 1.75rem;
  color: var(--color-dark);
  margin-bottom: 10px;
}

.page-hero p {
  color: var(--color-text-light);
  font-size: 0.95rem;
}

/* 首页横幅 */
.home-banner {
  background: linear-gradient(135deg, var(--color-dark) 0%, #334155 100%);
  color: var(--color-white);
  border-radius: var(--radius);
  padding: 40px 32px;
  margin-bottom: 32px;
}

.home-banner h1 {
  font-size: 2rem;
  margin-bottom: 12px;
}

.home-banner p {
  color: #cbd5e1;
  font-size: 1rem;
  max-width: 600px;
}

/* 区块标题 */
.section-title {
  font-size: 1.25rem;
  color: var(--color-dark);
  margin-bottom: 18px;
  padding-left: 12px;
  border-left: 4px solid var(--color-primary);
}

/* 卡片网格 */
.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-bottom: 36px;
}

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

.card-grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

.card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.2s, border-color 0.2s;
}

.card:hover {
  box-shadow: var(--shadow-md);
  border-color: #bfdbfe;
}

.card-icon {
  width: 44px;
  height: 44px;
  background: #eff6ff;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  margin-bottom: 14px;
}

.card h2,
.card h3 {
  font-size: 1.05rem;
  color: var(--color-dark);
  margin-bottom: 8px;
}

.card p {
  font-size: 0.88rem;
  color: var(--color-text-light);
  margin-bottom: 14px;
}

.card-link {
  font-size: 0.88rem;
  font-weight: 600;
}

/* 文章列表 */
.article-list {
  list-style: none;
}

.article-item {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 18px 22px;
  margin-bottom: 12px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  transition: border-color 0.2s;
}

.article-item:hover {
  border-color: #bfdbfe;
}

.article-item h3 {
  font-size: 1rem;
  color: var(--color-dark);
  margin-bottom: 4px;
}

.article-item .meta {
  font-size: 0.8rem;
  color: var(--color-text-light);
}

.article-item .tag {
  display: inline-block;
  background: #eff6ff;
  color: var(--color-primary);
  font-size: 0.75rem;
  padding: 2px 8px;
  border-radius: 4px;
  margin-right: 8px;
}

/* 内容页正文 */
.content-section {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  margin-bottom: 24px;
  box-shadow: var(--shadow-sm);
}

.content-section h2 {
  font-size: 1.2rem;
  color: var(--color-dark);
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid #eff6ff;
}

.content-section h3 {
  font-size: 1.05rem;
  color: var(--color-dark);
  margin: 18px 0 10px;
}

.content-section p,
.content-section li {
  color: var(--color-text);
  font-size: 0.95rem;
  margin-bottom: 10px;
}

.content-section ul,
.content-section ol {
  padding-left: 22px;
  margin-bottom: 14px;
}

/* 文章详情 */
.post-header {
  margin-bottom: 24px;
}

.post-header h1 {
  font-size: 1.6rem;
  color: var(--color-dark);
  margin-bottom: 10px;
}

.post-meta {
  font-size: 0.85rem;
  color: var(--color-text-light);
}

.post-body {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px 32px;
  margin-bottom: 28px;
  box-shadow: var(--shadow-sm);
}

.post-body h2 {
  font-size: 1.15rem;
  color: var(--color-dark);
  margin: 24px 0 12px;
}

.post-body h2:first-child {
  margin-top: 0;
}

.post-body p {
  margin-bottom: 14px;
  font-size: 0.95rem;
}

.post-body ul {
  padding-left: 22px;
  margin-bottom: 14px;
}

.post-body li {
  margin-bottom: 6px;
}

.post-contact {
  margin-top: 24px;
  padding-top: 16px;
  border-top: 1px solid var(--color-border);
  color: var(--color-text-light);
  font-size: 0.95rem;
}

.post-contact a {
  color: var(--color-primary);
  font-weight: 600;
}

/* 相关推荐 */
.related-posts {
  margin-top: 8px;
}

.related-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.related-list li a {
  display: block;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 14px 18px;
  font-size: 0.9rem;
  color: var(--color-text);
  transition: border-color 0.2s;
}

.related-list li a:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* 按钮 */
.btn {
  display: inline-block;
  padding: 10px 22px;
  background: var(--color-primary);
  color: var(--color-white);
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: background 0.2s;
}

.btn:hover {
  background: var(--color-primary-dark);
  color: var(--color-white);
}

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

.btn-outline:hover {
  background: #eff6ff;
  color: var(--color-primary-dark);
}

.back-link {
  margin-bottom: 20px;
  display: inline-block;
  font-size: 0.9rem;
}

/* 行业卡片 */
.industry-card {
  text-align: center;
}

.industry-card .card-icon {
  margin: 0 auto 14px;
}

/* 关于页 */
.about-info {
  line-height: 1.9;
}

.about-info p {
  margin-bottom: 14px;
}

/* 微信引流 */
.wechat-tip {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: var(--radius);
  padding: 16px 20px;
  font-size: 0.9rem;
  color: var(--color-text);
  margin-top: 24px;
}

.wechat-tip strong {
  color: var(--color-primary);
}

/* 响应式 */
@media (max-width: 900px) {
  .card-grid,
  .card-grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .nav-toggle {
    display: block;
  }

  .site-nav {
    display: none;
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background: var(--color-dark);
    flex-direction: column;
    padding: 12px 20px 20px;
    box-shadow: var(--shadow-md);
  }

  .site-nav.open {
    display: flex;
  }

  .site-nav a {
    padding: 12px 14px;
  }

  .card-grid,
  .card-grid-2,
  .card-grid-4 {
    grid-template-columns: 1fr;
  }

  .home-banner {
    padding: 28px 20px;
  }

  .home-banner h1 {
    font-size: 1.5rem;
  }

  .article-item {
    flex-direction: column;
    align-items: flex-start;
  }

  .related-list {
    grid-template-columns: 1fr;
  }

  .post-body {
    padding: 20px;
  }
}