/* Professional Industrial Design System */
:root {
    /* Color Palette - Professional Industrial */
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary: #1f2937;
    --secondary-light: #374151;
    --accent: #10b981;
    --accent-dark: #059669;
    --warning: #f59e0b;
    --error: #ef4444;
    
    /* Backgrounds */
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --bg-dark: #111827;
    
    /* Text */
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    --text-inverse: #ffffff;
    
    /* Borders */
    --border: #e5e7eb;
    --border-dark: #d1d5db;
    
    /* Shadows */
    --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);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
    
    /* Transitions */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.15s ease-out;
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Container */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.container-narrow {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* Typography */
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: 3.5rem;
    letter-spacing: -0.02em;
}

h2 {
    font-size: 2.5rem;
    letter-spacing: -0.01em;
}

h3 {
    font-size: 1.875rem;
}

h4 {
    font-size: 1.5rem;
}

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

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

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 0.5rem;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    white-space: nowrap;
}

/* Button with multiple text elements (span + small) */
.btn:has(> small),
.btn.btn-multi-line {
    flex-direction: column;
    gap: 0.5rem;
    white-space: normal;
}

.btn > span {
    display: block;
    line-height: 1.2;
    position: relative;
    z-index: 1;
}

.btn > small {
    display: block;
    line-height: 1.2;
    font-weight: 400;
    font-size: 0.75rem;
    opacity: 0.9;
    position: relative;
    z-index: 1;
}

.btn-primary {
    background: var(--primary);
    color: var(--text-inverse);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: var(--bg-tertiary);
    border-color: var(--border-dark);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: var(--text-inverse);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

/* Cards */
.card {
    background: var(--bg-primary);
    border-radius: 1rem;
    padding: var(--spacing-xl);
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: var(--transition);
}

.card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

/* Main Content */
main {
    flex: 1;
    min-height: 0;
}

/* Sections */
.section {
    padding: var(--spacing-xl) 0;
    position: relative;
    z-index: 2;
    scroll-margin-top: 70px;
    background: var(--bg-primary);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.section-subtitle {
    text-align: center;
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* Grids */
.grid {
    display: grid;
    gap: var(--spacing-lg);
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

/* Utilities */
.text-center {
    text-align: center;
}

.text-primary {
    color: var(--primary);
}

.text-secondary {
    color: var(--text-secondary);
}

.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing-md); }
.mt-3 { margin-top: var(--spacing-lg); }
.mt-4 { margin-top: var(--spacing-xl); }

.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-md); }
.mb-3 { margin-bottom: var(--spacing-lg); }
.mb-4 { margin-bottom: var(--spacing-xl); }

/* Loading States */
.loading {
    opacity: 0.6;
    pointer-events: none;
}

/* Accessibility */
.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;
}