:root{--primary: #10b981;--primary-hover: #059669;--secondary: #3b82f6;--accent: #f59e0b;--bg-main: #0f172a;--bg-card: #1e293b;--bg-hover: #334155;--text-main: #f8fafc;--text-muted: #94a3b8;--text-light: #e2e8f0;--border: #334155;--radius: 8px;--shadow: 0 4px 6px -1px rgb(0 0 0 / .1), 0 2px 4px -2px rgb(0 0 0 / .1);--font-sans: "Inter", system-ui, Avenir, Helvetica, Arial, sans-serif}*{box-sizing:border-box;margin:0;padding:0}body{font-family:var(--font-sans);background-color:var(--bg-main);color:var(--text-main);line-height:1.5;-webkit-font-smoothing:antialiased}a{color:var(--primary);text-decoration:none;transition:color .2s}a:hover{color:var(--primary-hover)}button{cursor:pointer;font-family:inherit}.container{max-width:1200px;margin:0 auto;padding:0 1rem}.btn{display:inline-flex;align-items:center;justify-content:center;padding:.5rem 1rem;border-radius:var(--radius);font-weight:500;transition:all .2s;border:none;font-size:.95rem}.btn-primary{background-color:var(--primary);color:#fff}.btn-primary:hover{background-color:var(--primary-hover)}.btn-outline{background-color:transparent;border:1px solid var(--border);color:var(--text-main)}.btn-outline:hover{background-color:var(--bg-hover)}.lesson-container{display:flex;height:100vh;flex-direction:column}.lesson-content-wrapper{display:flex;flex:1;overflow:hidden}.lesson-text-column{flex:1;padding:2rem;overflow-y:auto;border-right:1px solid var(--border);max-width:50%}.lesson-text-full{flex:1;padding:2rem;overflow-y:auto;max-width:100%;border-right:none}.lesson-widget-column{flex:1;padding:2rem;background-color:#0003;display:flex;flex-direction:column;overflow-y:auto}@media(max-width:900px){.lesson-container{height:auto;min-height:100vh}.lesson-content-wrapper{flex-direction:column;overflow:visible}.lesson-text-column{max-width:100%;border-right:none;border-bottom:1px solid var(--border);overflow-y:visible}.lesson-widget-column{overflow-y:visible}}@media(max-width:480px){.container{padding:0 .75rem}.lesson-text-column,.lesson-text-full,.lesson-widget-column{padding:1rem}}.mobile-wrap{flex-wrap:wrap}@media(max-width:600px){.mobile-wrap{flex-direction:column;align-items:stretch;gap:.75rem}}