:root{--color-primary: #0166b4;--color-primary-hover: #01589c;--color-primary-soft: #eaf3fb;--color-text: #212529;--color-text-muted: #6c757d;--color-border: #e5e7eb;--color-background: #ffffff;--color-background-soft: #f8f9fa;--container-width: 960px}*{box-sizing:border-box}html{font-family:Arial,Helvetica,sans-serif;background:var(--color-background);color:var(--color-text);font-size:20px}body{margin:0}main{max-width:var(--container-width);margin:40px auto;padding:0 20px 60px}h1{font-size:2rem}h2{font-size:1.5rem}h3{font-size:1.25rem}p,li{line-height:1.7}a{color:var(--color-primary);text-decoration:none}a:hover{color:var(--color-primary-hover);text-decoration:underline}.btn{display:inline-flex;align-items:center;justify-content:center;padding:.55rem 1rem;border:1px solid transparent;border-radius:6px;font-weight:600;line-height:1.2;text-decoration:none;cursor:pointer;transition:background-color .2s ease,color .2s ease,border-color .2s ease}.btn:hover{text-decoration:none}.btn-primary{background:var(--color-primary);border-color:var(--color-primary);color:#fff}.btn-primary:hover{background:var(--color-primary-hover);border-color:var(--color-primary-hover);color:#fff}.btn-outline-primary{background:transparent;border-color:var(--color-primary);color:var(--color-primary)}.btn-outline-primary:hover{background:var(--color-primary-soft);border-color:var(--color-primary);color:var(--color-primary-hover)}.lesson-content>*{margin-bottom:20px}.lesson-content h2{margin-top:32px}.lesson-content ul{margin-top:10px}.lesson-content>:last-child{margin-bottom:0}.lesson-list{list-style:none;padding:0;margin:0}.lesson-list li{border:1px solid var(--color-border);background:var(--color-background-soft);padding:16px;margin-bottom:12px;border-radius:6px;transition:all .2s ease;cursor:pointer}.lesson-list li:hover{background:var(--color-primary-soft);border-color:var(--color-primary);transform:translateY(-2px)}.lesson-list a{font-weight:600;color:var(--color-text);text-decoration:none;display:block}.lesson-list a:hover{color:var(--color-primary)}.tip-box{background:var(--color-primary-soft);border-left:4px solid var(--color-primary);padding:16px;margin:24px 0}.page-header{margin-bottom:32px;padding-bottom:20px;border-bottom:1px solid var(--color-border)}.page-header h1{margin-bottom:8px}.page-header p{color:var(--color-text-muted);font-size:1rem;margin:0}.lesson-nav{display:flex;justify-content:space-between;gap:16px;margin-top:32px;padding-top:24px;border-top:1px solid var(--color-border)}.lesson-nav div{flex:1}.lesson-nav div:last-child{text-align:right}.site-header{background:#fff;border-bottom:3px solid #dfe5ea}.site-header-inner{max-width:var(--container-width);margin:0 auto;padding:20px 20px 18px;display:flex;align-items:center;justify-content:space-between;gap:40px}.site-header-inner h2{margin:0}.main-nav{display:flex;align-items:center;gap:32px;font-size:18px;flex-shrink:0}.main-nav a{text-decoration:none;color:#333}.main-nav a:hover{color:var(--color-primary)}.main-nav .nav-auth{margin-left:20px;padding-left:20px;border-left:1px solid #ddd}.site-logo img{display:block;height:72px;width:auto}.site-logo-desktop img{height:80px}.site-logo-mobile{display:none}.site-logo-mobile img{height:36px}@media(max-width:600px){.site-logo-desktop{display:none}.site-logo-mobile{display:block}}.module-list{list-style:none;padding:0;margin:0}.module-list li{border:1px solid var(--color-border);background:var(--color-background-soft);padding:18px;margin-bottom:14px;border-radius:8px;transition:all .2s ease;cursor:pointer}.module-list li:hover{background:var(--color-primary-soft);border-color:var(--color-primary);transform:translateY(-2px)}.module-list a{font-weight:600;color:var(--color-text);text-decoration:none;display:block}.module-list a:hover{color:var(--color-primary)}.module-desc{display:block;font-weight:400;font-size:.9rem;color:var(--color-text-muted);margin-top:4px}.breadcrumb-link{display:inline-block;margin-bottom:12px;font-size:.95rem}.course-list{list-style:none;padding:0;margin:0 0 40px;display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:24px}.course-card{margin:0}.course-card a{display:block;background:#fff;border:1px solid var(--color-border);border-radius:12px;padding:16px;height:100%;text-decoration:none;color:var(--color-text);transition:border-color .2s ease,box-shadow .2s ease,transform .2s ease}.course-card a:hover{border-color:var(--color-primary);box-shadow:0 8px 20px #0000000f;transform:translateY(-2px);text-decoration:none}.course-thumb{width:100%;aspect-ratio:16 / 9;border-radius:8px;background:var(--color-background-soft);border:1px solid var(--color-border);display:flex;align-items:center;justify-content:center;color:var(--color-text-muted);font-size:.95rem;margin-bottom:14px}.course-thumb img{width:100%;height:100%;object-fit:cover;border-radius:8px;display:block}.course-card h3{margin:0;font-size:1.15rem;line-height:1.35;color:var(--color-text)}.course-card a:hover h3{color:var(--color-primary)}.video-wrapper{position:relative;padding-bottom:56.25%;height:0}.video-wrapper iframe{position:absolute;top:0;left:0;width:100%;height:100%;border:0}.site-footer[data-astro-cid-sz7xmlte]{border-top:1px solid #e5e7eb;padding:1.5rem 1rem}.site-footer-inner[data-astro-cid-sz7xmlte]{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:.75rem;text-align:center;font-size:.9rem}.site-footer-links[data-astro-cid-sz7xmlte]{display:flex;flex-wrap:wrap;justify-content:center;gap:.75rem}.site-footer-links[data-astro-cid-sz7xmlte] a[data-astro-cid-sz7xmlte]{text-decoration:none}