:root {
    /* Color Palette - Beam.ai Light Theme */
    --bg-dark: #ffffff;
    /* Base background is now white */
    --bg-card: #ffffff;
    --bg-card-hover: #f8fafc;
    --primary: #0055ff;
    /* Stronger Royal Blue */
    --primary-hover: #0044cc;
    --secondary: #64748b;
    --text-main: #020617;
    /* Very dark slate for main text */
    --text-muted: #475569;
    /* Slate 600 for secondary text */
    --border: #e2e8f0;
    /* Slate 200 */
    --success: #22c55e;

    /* Gradient Accents */
    --gradient-hero: radial-gradient(circle at 50% 0%, rgba(0, 85, 255, 0.08) 0%, rgba(255, 255, 255, 0) 60%);
    --gradient-mesh: radial-gradient(at 0% 0%, hsla(253, 16%, 7%, 1) 0, transparent 50%), radial-gradient(at 50% 0%, hsla(225, 39%, 30%, 1) 0, transparent 50%), radial-gradient(at 100% 0%, hsla(339, 49%, 30%, 1) 0, transparent 50%);

    /* Typography */
    --font-main: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

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

    /* Defaults */
    --radius-sm: 0.5rem;
    --radius-md: 1rem;
    --radius-lg: 1.5rem;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --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);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

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

body {
    font-family: var(--font-main);
    background-color: var(--bg-dark);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

button {
    cursor: pointer;
    border: none;
    background: none;
    font-family: inherit;
}

/* Utilities */
.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

.flex {
    display: flex;
}

.flex-col {
    flex-direction: column;
}

.items-center {
    align-items: center;
}

.justify-between {
    justify-content: space-between;
}

.justify-center {
    justify-content: center;
}

.gap-sm {
    gap: var(--spacing-sm);
}

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

.grid {
    display: grid;
}

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

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

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

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

.hidden {
    display: none !important;
}

/* Components */

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    transition: var(--transition);
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--primary);
    color: #fff;
    /* Always white on primary */
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.2), 0 4px 6px -2px rgba(0, 0, 0, 0.1);
}

.btn-outline {
    border: 1px solid var(--border);
    color: var(--text-main);
}

.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
}

/* Navbar */
.navbar {
    position: sticky;
    top: 0;
    z-index: 50;
    background-color: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.05em;
}

.nav-links {
    display: flex;
    gap: var(--spacing-md);
}

.nav-links a {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-muted);
    transition: var(--transition);
}

.nav-links a:hover {
    color: var(--primary);
}

.mobile-menu-btn {
    display: none;
    font-size: 1.5rem;
    color: var(--text-main);
}

/* Hero Section */
.hero {
    padding: var(--spacing-xl) 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: 50%;
    transform: translateX(-50%);
    width: 140vw;
    height: 100vh;
    background: var(--gradient-hero);
    z-index: -1;
    pointer-events: none;
}

.hero h1 {
    font-size: 4rem;
    line-height: 1.1;
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.04em;
    color: var(--text-main);
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto var(--spacing-md);
}

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

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

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

/* Efficiency Matrix (Cards) */
.feature-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.feature-card:hover {
    background-color: var(--bg-card-hover);
    transform: translateY(-4px);
    border-color: var(--primary);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    font-size: 2rem;
    margin-bottom: var(--spacing-sm);
    color: var(--primary);
}

.feature-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

/* Live AI Lab (Tabs) */
.lab-container {
    background-color: #ffffff;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.tabs-header {
    display: flex;
    border-bottom: 1px solid var(--border);
    background-color: #f8fafc;
}

.tab-btn {
    padding: 1rem 1.5rem;
    color: var(--text-muted);
    font-weight: 500;
    border-bottom: 2px solid transparent;
    transition: var(--transition);
}

.tab-btn:hover {
    color: var(--text-main);
    background-color: #f1f5f9;
}

.tab-btn.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

.tab-content {
    padding: var(--spacing-md);
    min-height: 400px;
}

.tab-pane {
    display: none;
    animation: fadeIn 0.4s ease;
}

.tab-pane.active {
    display: block;
}

/* Form Styles */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-muted);
}

.form-input,
.form-textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    background-color: #ffffff;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-main);
    font-family: inherit;
    transition: var(--transition);
}

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.2);
}

/* Footer */
footer {
    border-top: 1px solid var(--border);
    padding: var(--spacing-md) 0;
    margin-top: var(--spacing-lg);
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsiveness */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }

    .grid-3 {
        grid-template-columns: 1fr;
        gap: var(--spacing-sm);
    }

    .nav-links {
        display: none;
        /* Mobile menu logic in JS */
    }

    .mobile-menu-btn {
        display: block;
    }

    .tabs-header {
        flex-direction: column;
    }

    .tab-btn {
        text-align: left;
        border-bottom: 1px solid var(--border);
        border-left: 2px solid transparent;
    }

    .tab-btn.active {
        border-bottom: 1px solid var(--border);
        border-left-color: var(--primary);
    }
}