/* 4. DESIGN SYSTEM & CSS VARIABLES */
:root {
    /* Colors */
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary: #f8fafc;
    --secondary-hover: #e2e8f0;
    --accent: #38bdf8;
    
    --bg-main: #ffffff;
    --bg-light: #f1f5f9;
    --bg-dark: #0f172a;
    
    --text-main: #0f172a;
    --text-muted: #475569;
    --text-light: #f8fafc;
    
    --border: #e2e8f0;
    --success: #10b981;
    --error: #ef4444;

    /* A/B Badge Colors */
    --badge-a-bg: #dbeafe;
    --badge-a-text: #1e40af;
    --badge-b-bg: #d1fae5;
    --badge-b-text: #065f46;
    --badge-c-bg: #fef3c7;
    --badge-c-text: #92400e;

    /* Glassmorphism */
    --glass-bg: rgba(255, 255, 255, 0.85);
    --glass-border: rgba(255, 255, 255, 0.4);
    --glass-shadow: 0 8px 32px rgba(15, 23, 42, 0.1);

    /* Spacing & Layout */
    --container-width: 1200px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* RESET & BASE */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    color: var(--text-main);
    background-color: var(--bg-main);
    line-height: 1.6;
    overflow-x: hidden;
}

h1, h2, h3, h4 {
    font-weight: 800;
    line-height: 1.2;
    color: var(--text-main);
}

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

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
}

.text-center { text-align: center; }
.text-left { text-align: left; }
.bg-light { background-color: var(--bg-light); }
.section-padding { padding: 100px 0; }
.hidden { display: none !important; }

/* TYPOGRAPHY */
.section-title {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-muted);
    font-weight: 500;
    max-width: 600px;
    margin: 0 auto 48px;
}

/* BUTTONS */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: var(--transition);
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

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

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

.btn-secondary {
    background-color: transparent;
    border: 2px solid white;
    color: white;
}

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

.btn-sm { padding: 10px 20px; font-size: 0.875rem; }
.btn-large { padding: 16px 32px; font-size: 1.125rem; }
.btn-full { width: 100%; }

/* NAVBAR */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 24px 0;
    z-index: 1000;
    transition: var(--transition);
}

.navbar.scrolled {
    padding: 16px 0;
    background-color: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 4px 20px rgba(0,0,0,0.05);
    border-bottom: 1px solid var(--border);
}

.nav-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: white;
    letter-spacing: -0.5px;
}

.navbar.scrolled .logo {
    color: var(--text-main);
}

.logo span {
    color: var(--accent);
}

.navbar.scrolled .logo span {
    color: var(--primary);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-links a:not(.btn) {
    color: white;
    font-weight: 500;
    font-size: 0.95rem;
}

.navbar.scrolled .nav-links a:not(.btn) {
    color: var(--text-muted);
}

.navbar.scrolled .nav-links a:not(.btn):hover {
    color: var(--primary);
}

/* HERO SECTION */
.hero {
    position: relative;
    height: 100vh;
    min-height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background-image: url('assets/images/hero_bg.png');
    background-size: cover;
    background-position: center;
    color: white;
    padding: 0 20px;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, rgba(15, 23, 42, 0.4), rgba(15, 23, 42, 0.8));
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
}

.stars {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
    margin-bottom: 24px;
}

.star-icon {
    width: 20px;
    height: 20px;
    color: #fbbf24;
}

.rating-text {
    margin-left: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.hero-headline {
    font-size: 4rem;
    margin-bottom: 24px;
    letter-spacing: -1px;
    color: white;
}

.hero-subtitle {
    font-size: 1.25rem;
    font-weight: 400;
    margin-bottom: 40px;
    opacity: 0.9;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
}

/* SOCIAL PROOF */
.social-proof {
    background-color: var(--bg-main);
    padding: 32px 0;
    border-bottom: 1px solid var(--border);
}

.social-proof-desc {
    font-size: 0.875rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
    margin-bottom: 16px;
}

.logo-bar {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 40px;
    opacity: 0.6;
}

.mock-logo {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--text-main);
    letter-spacing: -0.5px;
    filter: grayscale(100%);
    transition: var(--transition);
}

.mock-logo:hover {
    filter: grayscale(0%);
    opacity: 1;
}

/* SERVICES GRID */
.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
    margin-top: 48px;
}

.service-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0,0,0,0.05);
    border: 1px solid var(--border);
    transition: var(--transition);
    text-align: left;
}

.service-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 30px rgba(0,0,0,0.1);
}

.service-img {
    width: 100%;
    height: 240px;
    object-fit: cover;
}

.service-content {
    padding: 24px;
}

.service-content h3 {
    font-size: 1.25rem;
    margin-bottom: 12px;
}

.service-content p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* BENEFITS SECTION */
.benefits-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
}

.benefits-desc {
    font-size: 1.125rem;
    color: var(--text-muted);
    margin-bottom: 32px;
}

.benefits-list {
    list-style: none;
}

.benefits-list li {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 24px;
}

.check-icon {
    width: 24px;
    height: 24px;
    color: var(--primary);
    flex-shrink: 0;
    margin-top: 2px;
}

.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid white;
    box-shadow: var(--glass-shadow);
    border-radius: 20px;
    padding: 40px;
    position: relative;
}

.quote-mark {
    position: absolute;
    top: 20px;
    left: 20px;
    font-size: 5rem;
    color: var(--primary);
    opacity: 0.1;
    font-family: serif;
    line-height: 1;
}

.testimonial-text {
    font-size: 1.25rem;
    font-style: italic;
    color: var(--text-main);
    margin-bottom: 24px;
    position: relative;
    z-index: 2;
}

.testimonial-author {
    display: flex;
    flex-direction: column;
}

.testimonial-author strong {
    font-size: 1.1rem;
}

.testimonial-author span {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* CONTACT SECTION */
.contact {
    background-color: var(--bg-dark);
    color: white;
}

.contact .section-title,
.contact .section-subtitle {
    color: white;
}

.contact .section-subtitle {
    opacity: 0.8;
}

.contact-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
}

.contact-details {
    margin-top: 40px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 20px;
    font-size: 1.05rem;
}

.contact-icon {
    width: 24px;
    height: 24px;
    color: var(--accent);
}

.contact-form-wrapper {
    position: relative;
}

.glass-form {
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    padding: 40px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.2);
}

.glass-form h3 {
    color: white;
    font-size: 1.5rem;
    margin-bottom: 24px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    color: #e2e8f0;
}

.form-group input {
    width: 100%;
    padding: 14px 16px;
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    background: rgba(255, 255, 255, 0.1);
    color: white;
    font-family: inherit;
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input::placeholder {
    color: rgba(255, 255, 255, 0.4);
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent);
    background: rgba(255, 255, 255, 0.15);
}

.form-success {
    margin-top: 20px;
    padding: 16px;
    background-color: rgba(16, 185, 129, 0.1);
    border: 1px solid var(--success);
    border-radius: 8px;
    color: #34d399;
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 500;
}

.form-success svg {
    width: 24px;
    height: 24px;
    flex-shrink: 0;
}

/* FOOTER */
.footer {
    background-color: #0b1120;
    padding: 40px 0;
    text-align: center;
    color: var(--text-muted);
}

.footer-logo {
    display: inline-block;
    margin-bottom: 16px;
    color: white !important;
}

.copyright {
    font-size: 0.9rem;
}

/* ANIMATIONS & UTILITIES */
.scroll-fade-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.scroll-slide-left {
    opacity: 0;
    transform: translateX(50px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.scroll-slide-right {
    opacity: 0;
    transform: translateX(-50px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.is-visible {
    opacity: 1 !important;
    transform: translate(0, 0) !important;
}

.style-delay-1 { transition-delay: 100ms; }
.style-delay-2 { transition-delay: 200ms; }
.style-delay-3 { transition-delay: 300ms; }

/* Dashboard Badges */
.badge {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}
.variant-a { background: var(--badge-a-bg); color: var(--badge-a-text); }
.variant-b { background: var(--badge-b-bg); color: var(--badge-b-text); }
.variant-c { background: var(--badge-c-bg); color: var(--badge-c-text); }

/* RESPONSIVE */
@media (max-width: 992px) {
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .benefits-layout, .contact-layout {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    .benefits-testimonial {
        order: -1;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none; /* simple hidden mobile nav for MVP */
    }
    .hero-headline {
        font-size: 2.5rem;
    }
    .hero-buttons {
        flex-direction: column;
    }
    .services-grid {
        grid-template-columns: 1fr;
    }
    .section-title {
        font-size: 2rem;
    }
    .glass-card, .glass-form {
        padding: 24px;
    }
}