*, *::before, *::after { box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; max-width: 860px; margin: 0 auto; padding: 24px 20px 60px; color: #1a1a2e; line-height: 1.7; }
a { color: #1a6bb5; text-decoration: none; }
.breadcrumb { font-size: 13px; color: #888; margin-bottom: 24px; }
.breadcrumb a { color: #888; }
.breadcrumb a:hover { text-decoration: underline; }
.badge { display: inline-block; font-size: 11px; font-weight: 600; padding: 2px 8px; border-radius: 10px; margin-bottom: 12px; text-transform: uppercase; letter-spacing: .5px; }
.badge-theory { background: #e8f4fd; color: #1a6bb5; }
.badge-task { background: #fff0e0; color: #c75a00; }
.badge-video { background: #f0e8ff; color: #6b1ab5; }
.badge-quiz { background: #e8fff0; color: #1ab55a; }
h1 { font-size: 1.8rem; margin: 0 0 24px; }
.content img { max-width: 100%; border-radius: 6px; margin: 12px 0; }
.content h1, .content h2, .content h3 { margin-top: 1.5em; }
.content pre { background: #f4f4f4; padding: 16px; border-radius: 6px; overflow-x: auto; font-size: 14px; }
.content code { background: #f4f4f4; padding: 2px 5px; border-radius: 3px; font-size: 13px; }
.content blockquote { border-left: 3px solid #ccc; margin: 0; padding-left: 16px; color: #555; }
.content table { border-collapse: collapse; width: 100%; margin: 16px 0; }
.content th, .content td { border: 1px solid #ddd; padding: 8px 12px; text-align: left; }
.content th { background: #f5f5f5; }
details { border: 1px solid #e5e7eb; border-radius: 6px; margin: 12px 0; padding: 12px 16px; }
summary { cursor: pointer; font-weight: 600; }
nav.pager { display: flex; justify-content: space-between; margin-top: 48px; padding-top: 20px; border-top: 1px solid #eee; gap: 12px; }
nav.pager a { text-decoration: none; color: #1a6bb5; font-size: 14px; max-width: 45%; }
nav.pager a:hover { text-decoration: underline; }
.pager-next { text-align: right; margin-left: auto; }