:root{--primary: #2563eb;--primary-dark: #1d4ed8;--text: #0f172a;--muted: #64748b;--surface: #ffffff;--surface-alt: #f8fafc;--border: #e2e8f0;--danger: #dc2626;--success: #16a34a;--radius: 10px;--radius-lg: 14px;--shadow-sm: 0 1px 2px rgba(15, 23, 42, .05);--shadow: 0 4px 16px rgba(15, 23, 42, .08)}*,*:before,*:after{box-sizing:border-box}html,body{margin:0;padding:0}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;background:var(--surface-alt);color:var(--text);line-height:1.5;-webkit-font-smoothing:antialiased}h1,h2,h3,h4{margin:0 0 .5em;line-height:1.25}h1{font-size:1.875rem}h2{font-size:1.4rem}h3{font-size:1.1rem}p{margin:0 0 1em}a{color:var(--primary)}button,input,textarea{font-family:inherit;font-size:inherit}.btn{display:inline-flex;align-items:center;justify-content:center;padding:.65rem 1.2rem;border-radius:var(--radius);border:1px solid transparent;background:var(--primary);color:#fff;font-weight:600;cursor:pointer;text-decoration:none;transition:background-color .12s ease}.btn:hover{background:var(--primary-dark)}.btn[disabled]{opacity:.6;cursor:not-allowed}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);padding:1.25rem;box-shadow:var(--shadow-sm)}@media (max-width: 640px){h1{font-size:1.5rem}}