/* ============================================
   CSS Variables - Design System
   ============================================ */
:root {
    /* Colors */
    --color-navy: #1D3557;
    --color-slate: #4C607B;
    --color-blue: #4A90E2;
    --color-charcoal: #2D3436;
    --color-text-primary: #2D3436;
    --color-text-secondary: #4C607B;
    --color-white: #FFFFFF;
    --color-off-white: #FAFAFA;
    --color-light-grey: #F8F9FA;
    --color-border: #E5E7EB;
    --color-light-grey-text: #9CA3AF;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-base: 18px;
    --font-size-h1: 56px;
    --font-size-h2: 40px;
    --font-size-h3: 28px;
    --font-size-h4: 20px;
    --line-height-base: 1.7;
    --line-height-heading: 1.2;

    /* Spacing */
    --spacing-xs: 8px;
    --spacing-sm: 16px;
    --spacing-md: 24px;
    --spacing-lg: 32px;
    --spacing-xl: 48px;
    --spacing-2xl: 64px;
    --spacing-3xl: 96px;

    /* Layout */
    --container-max-width: 1200px;
    --header-height: 80px;
    --header-height-scrolled: 72px;

    /* Effects */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --transition-speed: 200ms;
    --transition-easing: ease-in-out;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: var(--line-height-base);
    color: var(--color-text-primary);
    background-color: var(--color-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

h1 {
    font-size: var(--font-size-h1);
    font-weight: 700;
}

h2 {
    font-size: var(--font-size-h2);
    font-weight: 600;
}

h3 {
    font-size: var(--font-size-h3);
    font-weight: 600;
}

h4 {
    font-size: var(--font-size-h4);
    font-weight: 600;
}

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

a {
    color: var(--color-navy);
    text-decoration: none;
    transition: color var(--transition-speed) var(--transition-easing);
}

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

ul {
    list-style: none;
}

/* ============================================
   Utility Classes
   ============================================ */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-xl);
}

.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-navy);
    color: var(--color-white);
    padding: var(--spacing-sm);
    z-index: 100;
}

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

.placeholder-image {
    width: 100%;
    height: auto;
    background: var(--color-light-grey);
    display: flex;
    align-items: center;
    justify-content: center;
}

/* ============================================
   Buttons
   ============================================ */
.btn {
    display: inline-block;
    padding: 12px 32px;
    font-family: var(--font-family);
    font-size: 16px;
    font-weight: 500;
    text-align: center;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-speed) var(--transition-easing);
    border: 2px solid transparent;
    white-space: nowrap;
}

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

.btn-primary:hover {
    background-color: #3A7BC8;
    color: var(--color-white);
    box-shadow: var(--shadow-md);
}

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

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

.btn-cta {
    background-color: var(--color-blue);
    color: var(--color-white);
    padding: 16px 40px;
    font-size: 18px;
    font-weight: 600;
}

.btn-cta:hover {
    background-color: #3A7BC8;
    color: var(--color-white);
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

/* ============================================
   Header
   ============================================ */
.site-header {
    position: sticky;
    top: 0;
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
    transition: all var(--transition-speed) var(--transition-easing);
}

.site-header.scrolled {
    height: var(--header-height-scrolled);
    box-shadow: var(--shadow-sm);
}

.header-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-xl);
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

/* Logo */
.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
}

.logo-icon {
    width: 32px;
    height: 32px;
    background-color: var(--color-navy);
    color: var(--color-blue);
    font-family: var(--font-family);
    font-weight: 700;
    font-size: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 2px;
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
    color: var(--color-navy);
}

/* Main Navigation */
.main-nav ul {
    display: flex;
    gap: 40px;
    align-items: center;
}

.main-nav a {
    font-size: 16px;
    font-weight: 500;
    color: var(--color-navy);
    position: relative;
    padding: 8px 0;
}

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-blue);
    transition: width var(--transition-speed) var(--transition-easing);
}

.main-nav a:hover::after,
.main-nav a.active::after {
    width: 100%;
}

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

.main-nav a:focus {
    outline: 2px solid var(--color-blue);
    outline-offset: 2px;
}

/* Menu Toggle (Mobile) */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--color-navy);
    transition: all var(--transition-speed) var(--transition-easing);
}

/* Mobile Menu */
.mobile-menu {
    position: fixed;
    top: 0;
    right: -320px;
    width: 320px;
    height: 100vh;
    background-color: var(--color-white);
    z-index: 2000;
    padding: var(--spacing-xl);
    transition: right 300ms ease-out;
    box-shadow: var(--shadow-lg);
}

.mobile-menu.active {
    right: 0;
}

.mobile-menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1500;
    opacity: 0;
    visibility: hidden;
    transition: all 300ms ease-out;
}

.mobile-menu-overlay.active {
    opacity: 1;
    visibility: visible;
}

.menu-close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: none;
    border: none;
    font-size: 32px;
    color: var(--color-navy);
    cursor: pointer;
    padding: 8px;
    line-height: 1;
}

.mobile-menu nav ul {
    margin-top: var(--spacing-2xl);
}

.mobile-menu nav li {
    margin-bottom: var(--spacing-lg);
}

.mobile-menu nav a {
    font-size: 20px;
    font-weight: 500;
    color: var(--color-navy);
    display: block;
    padding: var(--spacing-sm);
}

.mobile-menu nav a:hover {
    background-color: var(--color-light-grey);
}

.mobile-menu-contact {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--color-border);
}

.mobile-menu-contact a {
    display: block;
    font-size: 16px;
    color: var(--color-slate);
    margin-bottom: var(--spacing-sm);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    padding: var(--spacing-3xl) 0;
    background-color: var(--color-white);
}

.hero-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-xl);
    display: grid;
    grid-template-columns: 60% 40%;
    gap: var(--spacing-2xl);
    align-items: center;
}

.hero-content h1 {
    margin-bottom: var(--spacing-md);
}

.hero-content p {
    font-size: 20px;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
}

.hero-image {
    width: 100%;
}

.hero-image svg {
    width: 100%;
    height: auto;
}

/* ============================================
   Stats Bar
   ============================================ */
.stats-bar {
    background-color: var(--color-light-grey);
    padding: var(--spacing-2xl) 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
    text-align: center;
}

.stat-number {
    font-size: 48px;
    font-weight: 700;
    color: var(--color-navy);
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    font-size: 16px;
    color: var(--color-slate);
}

/* ============================================
   About Section
   ============================================ */
.about {
    padding: var(--spacing-3xl) 0;
    background-color: var(--color-white);
}

.about h2 {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.about-content {
    max-width: 800px;
    margin: 0 auto var(--spacing-2xl);
    text-align: center;
}

.about-content p {
    font-size: 19px;
    color: var(--color-text-secondary);
}

.value-props {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-lg);
}

.value-prop {
    text-align: center;
}

.value-icon {
    font-size: 48px;
    margin-bottom: var(--spacing-md);
}

.value-prop h3 {
    font-size: 20px;
    margin-bottom: var(--spacing-sm);
}

.value-prop p {
    font-size: 16px;
    color: var(--color-text-secondary);
    margin-bottom: 0;
}

/* ============================================
   Services Section
   ============================================ */
.services {
    padding: var(--spacing-3xl) 0;
    background-color: var(--color-light-grey);
}

.services h2 {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.services-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.service-card {
    background-color: var(--color-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-speed) var(--transition-easing);
    border-left: 3px solid transparent;
}

.service-card:hover {
    border-left-color: var(--color-blue);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.service-number {
    font-size: 14px;
    font-weight: 600;
    color: var(--color-slate);
    margin-bottom: var(--spacing-sm);
}

.service-card h3 {
    margin-bottom: var(--spacing-md);
}

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

.service-link {
    color: var(--color-blue);
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.service-link:hover {
    text-decoration: underline;
}

/* ============================================
   Process Section
   ============================================ */
.process {
    padding: var(--spacing-3xl) 0;
    background-color: var(--color-white);
}

.process h2 {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.process-steps {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
}

.process-step {
    text-align: center;
    flex: 1;
    max-width: 200px;
}

.process-number {
    width: 48px;
    height: 48px;
    background-color: var(--color-navy);
    color: var(--color-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    font-weight: 700;
    margin: 0 auto var(--spacing-md);
}

.process-step h3 {
    font-size: 20px;
    margin-bottom: var(--spacing-sm);
}

.process-step p {
    font-size: 14px;
    color: var(--color-text-secondary);
    margin-bottom: 0;
}

.process-arrow {
    font-size: 24px;
    color: var(--color-blue);
    font-weight: 700;
}

/* ============================================
   Case Study Section
   ============================================ */
.case-study {
    padding: var(--spacing-3xl) 0;
    background-color: var(--color-light-grey);
}

.case-study-content {
    display: grid;
    grid-template-columns: 40% 60%;
    gap: var(--spacing-2xl);
    align-items: start;
}

.case-study-image {
    width: 100%;
}

.case-study-image svg {
    width: 100%;
    height: auto;
}

.case-study-text h3 {
    margin-bottom: var(--spacing-xl);
}

.case-study-section {
    margin-bottom: var(--spacing-lg);
}

.case-study-section h4 {
    font-size: 18px;
    color: var(--color-blue);
    margin-bottom: var(--spacing-sm);
}

.case-study-section p {
    color: var(--color-text-secondary);
}

.results-list {
    list-style: disc;
    padding-left: var(--spacing-md);
    color: var(--color-text-secondary);
}

.results-list li {
    margin-bottom: var(--spacing-xs);
}

.case-study-link {
    color: var(--color-blue);
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    margin-top: var(--spacing-md);
}

.case-study-link:hover {
    text-decoration: underline;
}

/* ============================================
   Insights Section
   ============================================ */
.insights {
    padding: var(--spacing-3xl) 0;
    background-color: var(--color-white);
}

.insights h2 {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.insights-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.insight-card {
    background-color: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    overflow: hidden;
    transition: all var(--transition-speed) var(--transition-easing);
}

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

.insight-image {
    width: 100%;
    aspect-ratio: 16 / 10;
    overflow: hidden;
}

.insight-image svg {
    width: 100%;
    height: 100%;
}

.insight-content {
    padding: var(--spacing-lg);
}

.insight-category {
    display: inline-block;
    background-color: var(--color-blue);
    color: var(--color-white);
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    padding: 4px 12px;
    border-radius: 12px;
    margin-bottom: var(--spacing-sm);
}

.insight-content h3 {
    font-size: 22px;
    margin-bottom: var(--spacing-sm);
}

.insight-content p {
    color: var(--color-text-secondary);
    font-size: 16px;
    margin-bottom: var(--spacing-sm);
}

.insight-meta {
    font-size: 14px;
    color: var(--color-slate);
}

.insights-cta {
    text-align: center;
}

/* ============================================
   Testimonials Section
   ============================================ */
.testimonials {
    padding: var(--spacing-3xl) 0;
    background-color: var(--color-light-grey);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.testimonial-card {
    background-color: var(--color-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-sm);
}

.testimonial-quote {
    font-size: 18px;
    font-style: italic;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.6;
}

.testimonial-author strong {
    display: block;
    font-weight: 600;
    color: var(--color-navy);
    margin-bottom: 4px;
}

.testimonial-author span {
    font-size: 14px;
    color: var(--color-slate);
}

/* ============================================
   CTA Section
   ============================================ */
.cta {
    padding: var(--spacing-3xl) 0;
    background-color: var(--color-navy);
    text-align: center;
}

.cta h2 {
    color: var(--color-white);
    margin-bottom: var(--spacing-md);
}

.cta p {
    color: var(--color-white);
    font-size: 20px;
    margin-bottom: var(--spacing-xl);
}

/* ============================================
   Footer
   ============================================ */
.site-footer {
    background-color: var(--color-charcoal);
    color: var(--color-white);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-xl);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: var(--spacing-xl);
}

.footer-logo .logo-icon {
    background-color: var(--color-white);
    color: var(--color-blue);
}

.footer-logo span {
    font-size: 20px;
    font-weight: 700;
    color: var(--color-white);
}

.footer-columns {
    display: grid;
    grid-template-columns: 25% 40% 35%;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-col h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--color-white);
    margin-bottom: var(--spacing-md);
}

.footer-col ul {
    list-style: none;
}

.footer-col li {
    margin-bottom: 12px;
}

.footer-col a {
    color: var(--color-light-grey-text);
    font-size: 15px;
    transition: color var(--transition-speed) var(--transition-easing);
}

.footer-col a:hover {
    color: var(--color-blue);
}

.tagline {
    text-align: center;
    color: var(--color-light-grey-text);
    font-size: 16px;
    margin: var(--spacing-xl) 0 var(--spacing-md);
}

.copyright {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.copyright p {
    font-size: 14px;
    color: var(--color-light-grey-text);
    margin: 0;
}

.legal-nav {
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
}

.legal-nav a {
    font-size: 14px;
    color: var(--color-light-grey-text);
}

.legal-nav span {
    color: var(--color-light-grey-text);
}

/* ============================================
   Responsive Design - Tablet
   ============================================ */
@media (max-width: 1024px) {
    :root {
        --font-size-h1: 48px;
        --font-size-h2: 36px;
        --font-size-h3: 24px;
        --font-size-base: 17px;
        --spacing-xl: 32px;
        --spacing-2xl: 48px;
        --spacing-3xl: 72px;
    }

    .hero-container {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }

    .hero-image {
        order: -1;
    }

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

    .process-steps {
        flex-wrap: wrap;
    }

    .process-arrow {
        display: none;
    }

    .case-study-content {
        grid-template-columns: 1fr;
    }

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

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

/* ============================================
   Responsive Design - Mobile
   ============================================ */
@media (max-width: 768px) {
    :root {
        --font-size-h1: 36px;
        --font-size-h2: 28px;
        --font-size-h3: 22px;
        --font-size-base: 16px;
        --spacing-xl: 20px;
        --spacing-2xl: 40px;
        --spacing-3xl: 56px;
        --header-height: 64px;
    }

    .container {
        padding: 0 var(--spacing-md);
    }

    .header-container {
        padding: 0 var(--spacing-md);
        height: var(--header-height);
    }

    .logo-text {
        font-size: 16px;
    }

    /* Hide desktop nav, show mobile menu */
    .main-nav {
        display: none;
    }

    .menu-toggle {
        display: flex;
    }

    /* Hero */
    .hero {
        padding: var(--spacing-2xl) 0;
    }

    .hero-content h1 {
        font-size: 32px;
    }

    .hero-content p {
        font-size: 18px;
    }

    .hero-cta {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .hero-cta .btn {
        width: 100%;
    }

    /* Stats */
    .stats-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }

    /* About */
    .value-props {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }

    /* Process */
    .process-steps {
        flex-direction: column;
    }

    /* Insights */
    .insights-grid {
        grid-template-columns: 1fr;
    }

    /* Footer */
    .footer-columns {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }

    .copyright {
        flex-direction: column;
        gap: var(--spacing-sm);
        text-align: center;
    }

    .legal-nav {
        flex-direction: column;
        gap: var(--spacing-xs);
    }

    .legal-nav span {
        display: none;
    }
}