:root {
    /* Colors - Premium B2B Palette */
    --color-primary: #0f172a;
    /* Slate 900 */
    --color-primary-light: #1e293b;
    /* Slate 800 */
    --color-accent: #0284c7;
    /* Sky 600 - Trust & Tech */
    --color-accent-hover: #0369a1;
    /* Sky 700 */
    --color-secondary: #0ea5e9;
    /* Sky 500 - Vibrant highlight */

    --color-bg: #ffffff;
    --color-bg-alt: #f8fafc;
    /* Slate 50 */
    --color-text: #334155;
    /* Slate 700 */
    --color-text-heading: #0f172a;
    /* Slate 900 */
    --color-text-light: #64748b;
    /* Slate 500 */
    --color-border: #e2e8f0;
    /* Slate 200 */

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 8rem;

    /* Typography */
    --font-family-base: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;
    --font-size-hero: 3.5rem;

    --line-height-base: 1.6;
    --line-height-heading: 1.2;

    /* Layout */
    --container-width: 1200px;
    --header-height: 80px;
    --radius-sm: 4px;
    --radius-md: 8px;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
}

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

html {
    font-family: var(--font-family-base);
    font-size: 16px;
    line-height: var(--line-height-base);
    color: var(--color-text);
    background-color: var(--color-bg);
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

img,
svg {
    display: block;
    max-width: 100%;
    height: auto;
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--color-accent-hover);
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    color: var(--color-text-heading);
    line-height: var(--line-height-heading);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

h1 {
    font-size: var(--font-size-4xl);
    letter-spacing: -0.025em;
}

h2 {
    font-size: var(--font-size-3xl);
    letter-spacing: -0.025em;
}

h3 {
    font-size: var(--font-size-2xl);
}

p {
    margin-bottom: var(--spacing-sm);
}

p.lead {
    font-size: var(--font-size-lg);
    color: var(--color-text-light);
}

/* Layout Utilities */
.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

.section {
    padding: var(--spacing-lg) 0;
}

.bg-light {
    background-color: var(--color-bg-alt);
}

.bg-dark {
    background-color: var(--color-primary);
    color: white;
}

.bg-dark h2,
.bg-dark p {
    color: white;
}

.grid {
    display: grid;
    gap: var(--spacing-md);
}

.grid-2 {
    grid-template-columns: 1fr;
}

.grid-3 {
    grid-template-columns: 1fr;
}

.grid-4 {
    grid-template-columns: 1fr;
}

@media (min-width: 768px) {
    .grid-2 {
        grid-template-columns: 1fr 1fr;
    }

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

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

    h1 {
        font-size: var(--font-size-hero);
    }
}

/* Header */
.header {
    height: var(--header-height);
    display: flex;
    align-items: center;
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(8px);
    z-index: 1000;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--color-text-heading);
}

.logo img {
    height: 32px;
    width: auto;
}

.nav ul {
    display: none;
    /* Mobile hidden by default */
    list-style: none;
    gap: var(--spacing-md);
}

.nav a {
    color: var(--color-text);
    font-weight: 500;
}

.nav a:hover,
.nav a.active {
    color: var(--color-accent);
}

/* Mobile Menu Toggle */
.mobile-toggle {
    display: block;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text-heading);
    margin-bottom: 5px;
    transition: 0.3s;
}

/* Desktop Nav */
@media (min-width: 768px) {
    .nav ul {
        display: flex;
    }

    .mobile-toggle {
        display: none;
    }
}

/* Mobile Nav Overlay */
.nav.is-open ul {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: var(--header-height);
    left: 0;
    width: 100%;
    background: white;
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-secondary) 100%);
    color: white;
    box-shadow: 0 4px 6px -1px rgba(2, 132, 199, 0.3), 0 2px 4px -1px rgba(2, 132, 199, 0.15);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--color-accent-hover) 0%, var(--color-accent) 100%);
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(2, 132, 199, 0.4), 0 4px 6px -2px rgba(2, 132, 199, 0.2);
}

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

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

.btn-secondary:hover {
    background-color: var(--color-accent);
    color: white;
}

.btn-large {
    padding: 1rem 2rem;
    font-size: var(--font-size-lg);
}

/* Cards & Content */
.card {
    background: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    transition: box-shadow 0.3s ease;
}

.card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-accent);
}

.feature-icon {
    width: 48px;
    height: 48px;
    background: var(--color-bg-alt);
    color: var(--color-accent);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    margin-bottom: var(--spacing-sm);
}

/* Footer */
.footer {
    background: var(--color-primary);
    color: white;
    padding: var(--spacing-xl) 0 var(--spacing-lg);
    margin-top: auto;
}

.footer h3 {
    color: white;
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
}

.footer a {
    color: #94a3b8;
    /* Slate 400 */
    display: block;
    margin-bottom: 0.5rem;
}

.footer a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid #334155;
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-md);
    text-align: center;
    color: #94a3b8;
    font-size: 0.875rem;
}

/* 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: 0;
}

/* Hero Section Specifics */
.hero {
    padding: var(--spacing-xl) 0;
    text-align: center;
}

.hero h1 span {
    color: var(--color-accent);
    display: block;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}