:root{--brand: #38B6FF;--brand-dark: #1a9fe0;--brand-light: #e8f4fd;--bg: #ffffff;--bg-alt: #f8fafc;--text: #1a1a2e;--text-muted: #64748b;--border: #e2e8f0;--success: #22c55e;--error: #ef4444;--line-green: #06C755;--radius: 8px;--radius-lg: 12px;--max-width: 1200px}*{margin:0;padding:0;box-sizing:border-box}body{font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,Noto Sans JP,sans-serif;color:var(--text);background:var(--bg);line-height:1.6}a{color:var(--brand-dark);text-decoration:none}a:hover{text-decoration:underline}.container{max-width:var(--max-width);margin:0 auto;padding:0 24px}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:10px 24px;border-radius:var(--radius);border:none;font-size:15px;font-weight:600;cursor:pointer;transition:all .2s}.btn-primary{background:var(--brand);color:#fff}.btn-primary:hover{background:var(--brand-dark);text-decoration:none}.btn-outline{background:transparent;color:var(--brand-dark);border:2px solid var(--brand)}.btn-outline:hover{background:var(--brand-light);text-decoration:none}.btn-line{background:var(--line-green);color:#fff}.btn-line:hover{background:#05b04d;text-decoration:none}.btn-block{width:100%}.card{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-lg);overflow:hidden;transition:box-shadow .2s}.card:hover{box-shadow:0 4px 12px #00000014}.badge{display:inline-block;padding:2px 8px;border-radius:4px;font-size:12px;font-weight:600}.badge-free{background:var(--brand-light);color:var(--brand-dark)}.badge-sample{background:#fef3c7;color:#92400e}.progress-bar{height:6px;background:var(--border);border-radius:3px;overflow:hidden}.progress-bar-fill{height:100%;background:var(--brand);border-radius:3px;transition:width .3s}.prose{max-width:72ch;line-height:1.8}.prose h1{font-size:28px;margin:32px 0 16px}.prose h2{font-size:22px;margin:28px 0 12px}.prose h3{font-size:18px;margin:24px 0 8px}.prose p{margin:12px 0}.prose ul,.prose ol{margin:12px 0;padding-left:24px}.prose code{background:#f1f5f9;padding:2px 6px;border-radius:4px;font-size:14px}.prose pre{background:#1e293b;color:#e2e8f0;padding:16px;border-radius:var(--radius);overflow-x:auto;margin:16px 0}.prose pre code{background:none;padding:0;color:inherit}.prose blockquote{border-left:3px solid var(--brand);padding-left:16px;color:var(--text-muted);margin:16px 0}.lesson-layout{display:flex;min-height:calc(100vh - 60px)}.lesson-sidebar{width:340px;min-width:340px;border-right:1px solid var(--border);background:var(--bg);overflow-y:auto;position:sticky;top:60px;height:calc(100vh - 60px);transition:margin-left .3s}.lesson-sidebar.closed{margin-left:-340px}.sidebar-header{display:flex;align-items:center;justify-content:space-between;padding:20px 16px;border-bottom:1px solid var(--border)}.sidebar-course-title{font-size:15px;font-weight:700;line-height:1.3;flex:1;margin-right:8px}.sidebar-close{background:none;border:none;font-size:22px;cursor:pointer;color:var(--text-muted);padding:4px 8px;line-height:1}.sidebar-close:hover{color:var(--text)}.sidebar-nav{padding:8px 0}.sidebar-section{border-bottom:1px solid var(--border)}.sidebar-section-header{display:flex;align-items:center;justify-content:space-between;width:100%;padding:14px 16px;background:none;border:none;cursor:pointer;text-align:left;gap:8px}.sidebar-section-header:hover{background:var(--bg-alt)}.sidebar-section-info{display:flex;flex-direction:column;gap:2px;flex:1}.sidebar-section-label{font-size:12px;color:var(--brand-dark);font-weight:600;text-transform:uppercase;letter-spacing:.02em}.sidebar-section-title{font-size:14px;font-weight:600;color:var(--text);line-height:1.3}.sidebar-chevron{font-size:12px;color:var(--text-muted);transition:transform .2s;flex-shrink:0}.sidebar-chevron.up{transform:rotate(180deg)}.sidebar-lessons{list-style:none;padding:0 0 8px}.sidebar-lesson{margin:0}.sidebar-lesson.current{background:var(--brand-light);border-left:3px solid var(--brand)}.sidebar-lesson-link{display:flex;align-items:flex-start;gap:10px;padding:10px 16px 10px 20px;text-decoration:none!important;color:inherit}.sidebar-lesson.current .sidebar-lesson-link{padding-left:17px}.sidebar-lesson-status{flex-shrink:0;width:20px;height:20px;display:flex;align-items:center;justify-content:center;border-radius:50%;font-size:12px;margin-top:2px;color:var(--text-muted);border:2px solid var(--border);background:var(--bg)}.sidebar-lesson-status.completed{background:var(--success);color:#fff;border-color:var(--success);font-weight:700}.sidebar-lesson-info{display:flex;flex-direction:column;gap:2px;min-width:0}.sidebar-lesson-title{font-size:13px;font-weight:500;color:var(--text);line-height:1.3}.sidebar-lesson-meta{font-size:12px;color:var(--text-muted)}.sidebar-lesson-link:hover .sidebar-lesson-title{color:var(--brand-dark)}.sidebar-toggle{position:fixed;left:0;top:80px;z-index:50;background:var(--bg);border:1px solid var(--border);border-left:none;border-radius:0 var(--radius) var(--radius) 0;padding:10px 12px;cursor:pointer;font-size:18px;color:var(--text-muted);box-shadow:2px 2px 8px #0000000f}.sidebar-toggle:hover{background:var(--bg-alt);color:var(--text)}.lesson-main{flex:1;min-width:0}.lesson-main.with-sidebar{max-width:calc(100% - 340px)}.lesson-content{max-width:800px;margin:0 auto;padding:40px 40px 64px}.prose table{width:100%;border-collapse:collapse;margin:16px 0;font-size:14px}.prose th,.prose td{border:1px solid var(--border);padding:8px 12px;text-align:left}.prose th{background:var(--bg-alt);font-weight:600}@media(max-width:1024px){.lesson-sidebar{position:fixed;left:0;top:60px;z-index:90;box-shadow:4px 0 16px #0000001a}.lesson-sidebar.closed{margin-left:-340px}.lesson-main.with-sidebar{max-width:100%}.lesson-content{padding:32px 24px 64px}}@media(max-width:768px){.container{padding:0 16px}.prose h1{font-size:24px}.lesson-sidebar{width:300px;min-width:300px}.lesson-sidebar.closed{margin-left:-300px}.lesson-content{padding:24px 16px 48px}}.nav[data-astro-cid-dmqpwcec]{border-bottom:1px solid var(--border);background:var(--bg);position:sticky;top:0;z-index:100}.nav-inner[data-astro-cid-dmqpwcec]{display:flex;align-items:center;justify-content:space-between;height:60px}.nav-logo[data-astro-cid-dmqpwcec]{font-size:20px;font-weight:700;color:var(--text);display:flex;align-items:center;gap:8px}.nav-logo[data-astro-cid-dmqpwcec]:hover{text-decoration:none}.nav-logo-icon[data-astro-cid-dmqpwcec]{color:var(--brand);font-size:16px}.nav-links[data-astro-cid-dmqpwcec]{display:flex;align-items:center;gap:24px}.nav-link[data-astro-cid-dmqpwcec]{color:var(--text-muted);font-size:14px;font-weight:500}.nav-link[data-astro-cid-dmqpwcec]:hover{color:var(--text);text-decoration:none}