:root{--color-primary: #3f51b5;--color-primary-dark: #303f9f;--color-primary-light: #c5cae9;--color-accent: #2196f3;--color-warning: #ff9800;--color-success: #4caf50;--color-background: #f5f5f5;--color-border: #e0e0e0;--color-text: #212121;--color-text-secondary: #757575}*{box-sizing:border-box;margin:0;padding:0}body{font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif;background:var(--color-background);color:var(--color-text)}.btn{padding:.75rem 1.5rem;border:none;border-radius:8px;font-size:1rem;font-weight:600;cursor:pointer;transition:all .3s;display:flex;align-items:center;justify-content:center;gap:.5rem}.btn:disabled{opacity:.6;cursor:not-allowed}