:root{--primary-color: #2563eb;--text-color: #1f2937;--light-gray: #f3f4f6;--border-color: #e5e7eb;--max-width: 720px}*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;line-height:1.6;color:var(--text-color);background:white;padding:20px}header{max-width:var(--max-width);margin:0 auto 40px;padding-bottom:20px;border-bottom:1px solid var(--border-color)}header h1{font-size:2.5em;margin-bottom:10px}.subtitle{color:#6b7280;font-size:1.1em}main{max-width:var(--max-width);margin:0 auto}h1,h2,h3{margin-top:30px;margin-bottom:15px}h1{font-size:2em}h2{font-size:1.5em}h3{font-size:1.2em}a{color:var(--primary-color);text-decoration:none}a:hover{text-decoration:underline}ol{list-style:none;counter-reset:principle-counter}ol li{counter-increment:principle-counter;margin:30px 0;padding-left:50px;position:relative}ol li::before{content:counter(principle-counter);position:absolute;left:0;top:0;background:var(--light-gray);width:35px;height:35px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-weight:bold}pre{background:var(--light-gray);padding:20px;border-radius:5px;overflow-x:auto;margin:20px 0;font-size:0.9em}code{background:var(--light-gray);padding:2px 5px;border-radius:3px;font-size:0.9em}.principle{margin-bottom:50px}.tagline{font-size:1.3em;color:#6b7280;font-style:italic;margin-bottom:30px}.principle-nav{display:flex;justify-content:space-between;margin:50px 0;padding-top:30px;border-top:1px solid var(--border-color)}footer{max-width:var(--max-width);margin:60px auto 20px;padding-top:30px;border-top:1px solid var(--border-color);text-align:center;color:#6b7280}footer a{color:#6b7280}.diagram{display:block;max-width:100%;height:auto;margin:30px auto;border:1px solid var(--border-color);border-radius:8px;background:white;padding:20px;box-shadow:0 2px 8px rgba(0,0,0,0.1)}@media (max-width: 768px){header h1{font-size:2em}ol li{padding-left:45px}.diagram{margin:20px auto;padding:15px}}