:root{--primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);--primary-color: #667eea;--primary-dark: #5a67d8;--primary-light: #7c92ed;--success-color: #10b981;--success-dark: #059669;--warning-color: #f59e0b;--warning-dark: #d97706;--danger-color: #ef4444;--danger-dark: #dc2626;--info-color: #3b82f6;--info-dark: #2563eb;--gray-50: #f9fafb;--gray-100: #f3f4f6;--gray-200: #e5e7eb;--gray-300: #d1d5db;--gray-400: #9ca3af;--gray-500: #6b7280;--gray-600: #4b5563;--gray-700: #374151;--gray-800: #1f2937;--gray-900: #111827;--radius-sm: 6px;--radius-md: 8px;--radius-lg: 12px;--radius-xl: 16px;--radius-full: 999px;--shadow-xs: 0 1px 2px rgba(0, 0, 0, .05);--shadow-sm: 0 1px 3px rgba(0, 0, 0, .1), 0 1px 2px rgba(0, 0, 0, .06);--shadow-md: 0 4px 6px rgba(0, 0, 0, .07), 0 2px 4px rgba(0, 0, 0, .06);--shadow-lg: 0 10px 15px rgba(0, 0, 0, .1), 0 4px 6px rgba(0, 0, 0, .05);--shadow-xl: 0 20px 25px rgba(0, 0, 0, .1), 0 10px 10px rgba(0, 0, 0, .04);--shadow-primary: 0 4px 12px rgba(102, 126, 234, .25);--shadow-primary-lg: 0 8px 20px rgba(102, 126, 234, .3);--transition-fast: .15s cubic-bezier(.4, 0, .2, 1);--transition-base: .2s cubic-bezier(.4, 0, .2, 1);--transition-slow: .3s cubic-bezier(.4, 0, .2, 1)}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:10px 20px;font-size:15px;line-height:1.5;font-weight:600;font-family:inherit;border-radius:var(--radius-md);border:1px solid transparent;background:transparent;cursor:pointer;-webkit-user-select:none;user-select:none;white-space:nowrap;text-decoration:none;transition:all var(--transition-base);-webkit-tap-highlight-color:transparent}.btn:focus-visible{outline:2px solid var(--primary-color);outline-offset:2px}.btn:disabled,.btn.disabled{opacity:.5;cursor:not-allowed;pointer-events:none}.btn-sm{padding:8px 16px;font-size:14px;border-radius:var(--radius-sm);gap:6px}.btn-lg{padding:12px 28px;font-size:16px;border-radius:var(--radius-lg);gap:10px}.btn-xl{padding:16px 36px;font-size:18px;border-radius:var(--radius-xl);gap:12px}.btn-primary{background:var(--primary-gradient);color:#fff;border-color:transparent;box-shadow:var(--shadow-primary)}.btn-primary:hover:not(:disabled){transform:translateY(-1px);box-shadow:var(--shadow-primary-lg)}.btn-primary:active:not(:disabled){transform:translateY(0);box-shadow:var(--shadow-primary)}.btn-secondary{background:var(--gray-100);color:var(--gray-900);border-color:var(--gray-200)}.btn-secondary:hover:not(:disabled){background:var(--gray-200);border-color:var(--gray-300)}.btn-secondary:active:not(:disabled){background:var(--gray-300)}.btn-outline{background:transparent;color:var(--primary-color);border-color:var(--primary-color);border-width:1.5px}.btn-outline:hover:not(:disabled){background:#667eea14;border-color:var(--primary-dark);color:var(--primary-dark)}.btn-outline:active:not(:disabled){background:#667eea1f}.btn-ghost{background:transparent;color:var(--gray-700);border-color:transparent}.btn-ghost:hover:not(:disabled){background:var(--gray-100);color:var(--gray-900)}.btn-ghost:active:not(:disabled){background:var(--gray-200)}.btn-link{background:transparent;color:var(--primary-color);border-color:transparent;padding-left:0;padding-right:0}.btn-link:hover:not(:disabled){color:var(--primary-dark);text-decoration:underline}.btn-success{background:var(--success-color);color:#fff;border-color:transparent}.btn-success:hover:not(:disabled){background:var(--success-dark);transform:translateY(-1px);box-shadow:0 4px 12px #10b98140}.btn-warning{background:var(--warning-color);color:#fff;border-color:transparent}.btn-warning:hover:not(:disabled){background:var(--warning-dark);transform:translateY(-1px);box-shadow:0 4px 12px #f59e0b40}.btn-danger{background:var(--danger-color);color:#fff;border-color:transparent}.btn-danger:hover:not(:disabled){background:var(--danger-dark);transform:translateY(-1px);box-shadow:0 4px 12px #ef444440}.btn-info{background:var(--info-color);color:#fff;border-color:transparent}.btn-info:hover:not(:disabled){background:var(--info-dark);transform:translateY(-1px);box-shadow:0 4px 12px #3b82f640}.btn-outline-success{background:transparent;color:var(--success-color);border-color:var(--success-color);border-width:1.5px}.btn-outline-success:hover:not(:disabled){background:#10b98114;color:var(--success-dark);border-color:var(--success-dark)}.btn-outline-warning{background:transparent;color:var(--warning-color);border-color:var(--warning-color);border-width:1.5px}.btn-outline-warning:hover:not(:disabled){background:#f59e0b14;color:var(--warning-dark);border-color:var(--warning-dark)}.btn-outline-danger{background:transparent;color:var(--danger-color);border-color:var(--danger-color);border-width:1.5px}.btn-outline-danger:hover:not(:disabled){background:#ef444414;color:var(--danger-dark);border-color:var(--danger-dark)}.btn-outline-info{background:transparent;color:var(--info-color);border-color:var(--info-color);border-width:1.5px}.btn-outline-info:hover:not(:disabled){background:#3b82f614;color:var(--info-dark);border-color:var(--info-dark)}.btn-pill{border-radius:var(--radius-full)}.btn-circle{border-radius:50%;padding:10px;aspect-ratio:1}.btn-circle.btn-sm{padding:8px}.btn-circle.btn-lg{padding:12px}.btn-square{padding:10px;aspect-ratio:1}.btn-square.btn-sm{padding:8px}.btn-square.btn-lg{padding:12px}.btn-block{width:100%;display:flex}.btn-group{display:inline-flex;gap:0}.btn-group .btn{border-radius:0;margin-right:-1px}.btn-group .btn:first-child{border-top-left-radius:var(--radius-md);border-bottom-left-radius:var(--radius-md)}.btn-group .btn:last-child{border-top-right-radius:var(--radius-md);border-bottom-right-radius:var(--radius-md);margin-right:0}.btn-group .btn:hover,.btn-group .btn:focus{z-index:1}.btn-loading{position:relative;color:transparent!important;pointer-events:none}.btn-loading:after{content:"";position:absolute;width:16px;height:16px;top:50%;left:50%;margin-left:-8px;margin-top:-8px;border:2px solid currentColor;border-radius:50%;border-right-color:transparent;animation:btn-spin .6s linear infinite}@keyframes btn-spin{to{transform:rotate(360deg)}}.btn-icon-left{padding-left:16px}.btn-icon-right{padding-right:16px}.btn svg,.btn i{flex-shrink:0}@media(max-width:640px){.btn-lg{padding:10px 24px;font-size:15px}.btn-xl{padding:12px 28px;font-size:16px}}@media(prefers-color-scheme:dark){.btn-secondary{background:var(--gray-700);color:var(--gray-100);border-color:var(--gray-600)}.btn-secondary:hover:not(:disabled){background:var(--gray-600);border-color:var(--gray-500)}.btn-ghost{color:var(--gray-300)}.btn-ghost:hover:not(:disabled){background:var(--gray-800);color:var(--gray-100)}}