:root {
    
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary: #64748b;
    --accent: #0ea5e9;
    
    
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #3b82f6;
    
    
    --dark: #0f172a;
    --dark-light: #1e293b;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --gray-900: #0f172a;
    
    
    --bg-primary: #ffffff;
    --bg-secondary: var(--gray-50);
    --bg-dark: var(--dark);
    
    
    --text-primary: var(--dark);
    --text-secondary: var(--gray-600);
    --text-muted: var(--gray-500);
    
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    
    
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    
    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-full: 9999px;
    
    
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    
    
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    
    
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
}



*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    overflow-x: hidden;
}




*:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
    border-radius: var(--radius-sm);
}


.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary);
    color: white;
    padding: var(--spacing-sm) var(--spacing-md);
    text-decoration: none;
    z-index: var(--z-tooltip);
    border-radius: 0 0 var(--radius) 0;
}

.skip-link:focus {
    top: 0;
}


[aria-hidden="true"] {
    display: none;
}



h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--primary-dark);
}



.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: 0.9375rem;
    font-weight: 600;
    line-height: 1.5;
    border: 1px solid transparent;
    border-radius: var(--radius);
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    position: relative;
    overflow: hidden;
    user-select: none;
    white-space: nowrap;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:active::before {
    width: 300px;
    height: 300px;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    pointer-events: none;
}


.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    background: var(--primary-dark);
    box-shadow: var(--shadow-lg);
    transform: translateY(-1px);
}

.btn-primary:active {
    transform: translateY(0);
    box-shadow: var(--shadow);
}


.btn-secondary {
    background: white;
    color: var(--primary);
    border-color: var(--gray-300);
    box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
    background: var(--gray-50);
    border-color: var(--primary);
    box-shadow: var(--shadow);
}


.btn-ghost {
    background: transparent;
    color: var(--primary);
    border-color: transparent;
}

.btn-ghost:hover {
    background: var(--gray-100);
}


.btn-danger {
    background: var(--danger);
    color: white;
}

.btn-danger:hover {
    background: #dc2626;
}


.btn-sm {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: 0.875rem;
}

.btn-lg {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1rem;
}



.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.form-label.required::after {
    content: ' *';
    color: var(--danger);
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.9375rem;
    line-height: 1.5;
    color: var(--text-primary);
    background-color: white;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    transition: all var(--transition-fast);
    font-family: inherit;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-input:invalid:not(:placeholder-shown),
.form-select:invalid:not(:placeholder-shown) {
    border-color: var(--danger);
}

.form-input:valid:not(:placeholder-shown) {
    border-color: var(--success);
}

.form-textarea {
    min-height: 120px;
    resize: vertical;
}

.form-help {
    display: block;
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-top: var(--spacing-xs);
}

.form-error {
    display: block;
    font-size: 0.875rem;
    color: var(--danger);
    margin-top: var(--spacing-xs);
}


.form-check {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.form-check-input {
    width: 1.25rem;
    height: 1.25rem;
    margin-top: 0.125rem;
    cursor: pointer;
    accent-color: var(--primary);
}

.form-check-label {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    cursor: pointer;
}



.card {
    background: white;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: all var(--transition-base);
}

.card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.card-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--gray-200);
    background: var(--gray-50);
}

.card-body {
    padding: var(--spacing-lg);
}

.card-footer {
    padding: var(--spacing-lg);
    border-top: 1px solid var(--gray-200);
    background: var(--gray-50);
}



.alert {
    padding: var(--spacing-md);
    border-radius: var(--radius);
    border: 1px solid;
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
}

.alert-icon {
    flex-shrink: 0;
    font-size: 1.25rem;
}

.alert-success {
    background: #ecfdf5;
    border-color: #a7f3d0;
    color: #065f46;
}

.alert-danger {
    background: #fff1f2;
    border-color: #fecdd3;
    color: #991b1b;
}

.alert-warning {
    background: #fffbeb;
    border-color: #fde68a;
    color: #92400e;
}

.alert-info {
    background: #eff6ff;
    border-color: #bfdbfe;
    color: #1e40af;
}


.toast-container {
    position: fixed;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: var(--z-tooltip);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    max-width: 400px;
}

.toast {
    background: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow-xl);
    padding: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    animation: slideInRight 0.3s ease-out;
    border-left: 4px solid;
}

.toast-success { border-left-color: var(--success); }
.toast-error { border-left-color: var(--danger); }
.toast-warning { border-left-color: var(--warning); }
.toast-info { border-left-color: var(--info); }

@keyframes slideInRight {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}



.loading-spinner {
    display: inline-block;
    width: 1.5rem;
    height: 1.5rem;
    border: 3px solid var(--gray-200);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.skeleton {
    background: linear-gradient(
        90deg,
        var(--gray-200) 25%,
        var(--gray-100) 50%,
        var(--gray-200) 75%
    );
    background-size: 200% 100%;
    animation: loading 1.5s ease-in-out infinite;
    border-radius: var(--radius);
}

@keyframes loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}



.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-md);
    }
    
    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.5rem; }
}



.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing-md); }
.mt-3 { margin-top: var(--spacing-lg); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-md); }
.mb-3 { margin-bottom: var(--spacing-lg); }

.hidden { display: none; }
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}