:root{--color-primary:#3b1e43;--color-primary-rgb:59,30,67;--color-accent:#ddbc91;--color-accent-rgb:221,188,145;--color-bg:#fafafa;--color-surface:#fff;--color-surface-hover:#fcfcfc;--color-text-main:#222;--color-text-muted:#555;--color-border:#e2d9cd;--color-border-hover:#c5b8a5;--color-success:#2e7d32;--color-success-bg:#e8f5e9;--shadow-sm:0 1px 2px #3b1e430d;--shadow-md:0 4px 6px -1px #3b1e431a,0 2px 4px -1px #3b1e430f;--shadow-lg:0 10px 15px -3px #3b1e431a,0 4px 6px -2px #3b1e430d;--radius:8px;--radius-lg:12px}*{box-sizing:border-box;margin:0;padding:0}body{background:var(--color-bg);color:var(--color-text-main);-webkit-font-smoothing:antialiased;min-height:100vh;font-family:Helvetica Neue,Helvetica,Arial,sans-serif;line-height:1.6}a{color:inherit;text-decoration:none;transition:color .2s}.container{max-width:1200px;margin:0 auto;padding:0 1.5rem}h1,h2,h3,h4,h5,h6{color:var(--color-text-main);font-family:Helvetica Neue,Helvetica,Arial,sans-serif;font-weight:700;line-height:1.2}p{color:var(--color-text-muted)}.btn{border-radius:var(--radius);cursor:pointer;text-transform:uppercase;letter-spacing:.05em;border:1px solid #0000;justify-content:center;align-items:center;gap:.5rem;padding:.625rem 1.25rem;font-family:Helvetica Neue,Helvetica,Arial,sans-serif;font-size:.95rem;font-weight:700;transition:all .2s;display:inline-flex}.btn:disabled{opacity:.6;cursor:not-allowed}.btn-primary{background:var(--color-primary);color:#fff;box-shadow:0 2px 4px #3b1e4333}.btn-primary:not(:disabled):hover{background:#2d1633;transform:translateY(-1px)}.btn-secondary{background:var(--color-surface);border:1px solid var(--color-border);color:var(--color-text-main)}.btn-secondary:not(:disabled):hover{border-color:var(--color-border-hover);background:var(--color-surface-hover)}.card{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-lg);box-shadow:var(--shadow-sm);padding:1.5rem;transition:transform .2s,box-shadow .2s}.card:hover{border-color:var(--color-accent)}.card-hover:hover{box-shadow:var(--shadow-md);transform:translateY(-2px)}input,textarea,select{border:1px solid var(--color-border);border-radius:var(--radius);background:var(--color-surface);width:100%;color:var(--color-text-main);padding:.75rem;font-size:1rem;transition:border-color .2s,box-shadow .2s}input:focus,textarea:focus,select:focus{border-color:var(--color-primary);outline:none;box-shadow:0 0 0 3px #3b1e431a}.loader{border:2px solid #ffffff4d;border-top-color:currentColor;border-radius:50%;width:20px;height:20px;animation:.8s linear infinite spin}.loader-dark{border-color:#3b1e431a;border-top-color:var(--color-primary)}@keyframes spin{to{transform:rotate(360deg)}}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.animate-fade-in{animation:.4s ease-out forwards fadeIn}.progress-container{background:var(--color-border);border-radius:4px;height:8px;overflow:hidden}.progress-fill{background:var(--color-primary);height:100%;transition:width .5s ease-out}.video-container{border-radius:var(--radius-lg);width:100%;height:0;box-shadow:var(--shadow-lg);background:#000;margin-bottom:2rem;padding-top:56.25%;position:relative}@supports (aspect-ratio:16 / 9){.video-container{aspect-ratio:16/9;height:auto;padding-top:0}}.video-container iframe{border-radius:var(--radius-lg);border:none;width:100%;height:100%;display:block;position:absolute;top:0;left:0}@keyframes shimmer{0%{background-position:200% 0}to{background-position:-200% 0}}.video-mobile-hint{display:none}@media (max-width:768px){.video-mobile-hint{color:var(--color-text-muted);text-align:center;margin-top:-1.25rem;margin-bottom:1.5rem;font-size:.8rem;display:block}}.course-layout{height:calc(100vh - 64px);margin-top:64px;display:flex}.course-sidebar{background:var(--color-surface);border-right:1px solid var(--color-border);flex-direction:column;width:320px;padding:1.5rem;display:flex;overflow-y:auto}.course-main{background:var(--color-bg);flex:1;padding:2rem 3rem;overflow-y:auto}.navbar-container{background:var(--color-surface);border-bottom:1px solid var(--color-border);z-index:100;width:100%;height:64px;box-shadow:var(--shadow-sm);justify-content:space-between;align-items:center;padding:1rem 2rem;display:flex;position:fixed;top:0}@media (max-width:768px){.course-layout{flex-direction:column;height:auto;margin-top:64px}.course-sidebar{border-right:none;border-bottom:1px solid var(--color-border);order:2;width:100%;height:auto;max-height:250px}.course-main{flex:none;order:1;width:100%;height:auto;padding:1rem;overflow-y:visible}.navbar-container{padding:.5rem 1rem}.navbar-logo-text{font-size:1.1rem}.hide-on-mobile{display:none}}.admin-layout{min-height:100vh;display:flex}.admin-sidebar{background:var(--color-primary);color:#fff;width:250px;padding:2rem 1rem}.admin-main{background:#f5f5f5;flex:1;padding:2rem}@media (max-width:768px){.admin-layout{flex-direction:column}.admin-sidebar{width:100%;height:auto;padding:1rem}.admin-main{padding:1rem}}.desktop-nav{align-items:center;gap:1rem;display:flex}.mobile-menu-btn{cursor:pointer;color:var(--color-text-main);background:0 0;border:none;padding:.5rem;display:none}.mobile-menu-overlay{background:var(--color-surface);border-bottom:1px solid var(--color-border);width:100%;box-shadow:var(--shadow-md);z-index:99;flex-direction:column;gap:1rem;padding:1.5rem;animation:.3s ease-out slideDown;display:none;position:fixed;top:64px;left:0}.mobile-menu-overlay.open{display:flex}@keyframes slideDown{0%{opacity:0;transform:translateY(-10px)}to{opacity:1;transform:translateY(0)}}@media (max-width:768px){.desktop-nav{display:none}.mobile-menu-btn{justify-content:center;align-items:center;display:flex}}