* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; line-height: 1.7; color: #2d3748; background: #f7fafc; }
.container { max-width: 900px; margin: 0 auto; padding: 2rem 1.5rem; }
h1 { font-size: 2rem; color: #1a202c; margin-bottom: 0.5rem; }
h2 { font-size: 1.5rem; color: #2d3748; margin-top: 2rem; margin-bottom: 0.75rem; border-bottom: 2px solid #e2e8f0; padding-bottom: 0.3rem; }
h3 { font-size: 1.2rem; color: #4a5568; margin-top: 1.5rem; margin-bottom: 0.5rem; }
h4 { font-size: 1.05rem; color: #4a5568; margin-top: 1.2rem; margin-bottom: 0.4rem; }
p { margin-bottom: 1rem; }
a { color: #3182ce; text-decoration: none; }
a:hover { text-decoration: underline; }
ul, ol { margin: 0.5rem 0 1rem 1.5rem; }
li { margin-bottom: 0.3rem; }
table { width: 100%; border-collapse: collapse; margin: 1rem 0; }
th, td { padding: 0.5rem 0.75rem; border: 1px solid #e2e8f0; text-align: left; }
th { background: #edf2f7; font-weight: 600; }
tr:nth-child(even) { background: #f7fafc; }
blockquote { border-left: 4px solid #3182ce; padding: 0.5rem 1rem; margin: 1rem 0; background: #ebf8ff; color: #2a4365; font-style: italic; }
code { background: #edf2f7; padding: 0.15rem 0.4rem; border-radius: 4px; font-size: 0.9em; }
hr { border: none; border-top: 2px solid #e2e8f0; margin: 2rem 0; }
.nav { background: #2d3748; padding: 1rem 1.5rem; }
.nav a { color: #e2e8f0; margin-right: 1.5rem; font-weight: 500; }
.nav a:hover { color: #fff; text-decoration: none; }
.card { background: #fff; border-radius: 8px; padding: 1.5rem; margin-bottom: 1rem; box-shadow: 0 1px 3px rgba(0,0,0,0.1); }
.card h3 { margin-top: 0; }
.section-label { font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.05em; color: #718096; font-weight: 600; margin-bottom: 0.5rem; }
input[type="checkbox"] { margin-right: 0.5rem; }