:root{--brand-mint:#6ee7b7;--brand-mint-strong:#34d399;--bg:#f1f5f9;--surface:#fff;--surface-muted:#f8fafc;--text:#1f2937;--text-muted:#64748b;--text-invert:#fff;--border:#e2e8f0;--shadow:0 10px 28px rgba(0,0,0,.08);--shadow-soft:0 4px 12px rgba(0,0,0,.06);--dark-bg:#0b0f14;--dark-surface:#101826;--dark-border:hsla(0,0%,100%,.12)}body{margin:0;padding:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background:var(--bg);color:var(--text)}*{box-sizing:border-box}.container{max-width:1200px;margin:0 auto;padding:0 20px}.srOnly{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.login-page{display:flex;align-items:center;justify-content:center;min-height:100vh;background-color:#f5f5f5}.login-form{background:#fff;padding:40px;border-radius:8px;box-shadow:0 2px 10px rgba(0,0,0,.1);min-width:300px}.login-form h2{margin-top:0;color:#333}.form-group{margin-bottom:20px}.form-group label{display:block;margin-bottom:8px;color:#333;font-weight:500}.form-group input{width:100%;padding:10px;border:1px solid #ddd;border-radius:4px;font-size:16px}.form-group input:focus{outline:none;border-color:#4caf50}.login-form button{width:100%;padding:12px;background-color:#4caf50;color:#fff;border:none;border-radius:4px;font-size:16px;font-weight:600;cursor:pointer;transition:background-color .3s}.login-form button:hover:not(:disabled){background-color:#45a049}.login-form button:disabled{background-color:#ccc;cursor:not-allowed}.error{color:#d32f2f;margin-top:10px;padding:10px;background-color:#ffebee;border-radius:4px}.dashboard{min-height:100vh;background-color:#f5f5f5}.dashboard-header{background-color:#333;color:#fff;padding:20px;display:flex;justify-content:space-between;align-items:center}.dashboard-header h1{margin:0}.dashboard-header button{padding:10px 20px;background-color:#4caf50;color:#fff;border:none;border-radius:4px;cursor:pointer;font-size:14px}.dashboard-header button:hover{background-color:#45a049}.dashboard-content{padding:40px 20px}.dashboard-content h2{color:#333;margin-bottom:30px}.courses-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));grid-gap:20px;gap:20px}.course-card{background:#fff;padding:20px;border-radius:8px;box-shadow:0 2px 10px rgba(0,0,0,.1)}.course-card h3{margin-top:0;color:#333}.course-card p{color:#666;font-size:14px;margin-bottom:20px}.course-card button{width:100%;padding:10px;background-color:#4caf50;color:#fff;border:none;border-radius:4px;cursor:pointer;font-weight:600}.course-card button:hover{background-color:#45a049}.video-player-container{background:#fff;padding:30px;border-radius:8px;box-shadow:0 2px 10px rgba(0,0,0,.1)}.video-player-container h2{margin-top:0;color:#333}.video-wrapper{margin-bottom:30px}