/* ============================================
   CSS VARIABLES
   ============================================ */

:root {
    /* Colors - Enhanced Palette */
    --gradient-start: #0EA5E9;
    --gradient-mid: #3B82F6;
    --gradient-end: #6366F1;
    --gradient-accent: #8B5CF6;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #64748b;
    --bg-white: #ffffff;
    --bg-light: #f8fafc;
    --bg-dark: #0f172a;
    --bg-gradient-light: linear-gradient(180deg, #f0f9ff 0%, #faf5ff 100%);
    --bg-gradient-premium: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 5rem;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    --radius-2xl: 32px;
    --radius-full: 9999px;
    
    /* Shadows - Layered & Sophisticated */
    --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.04), 0 1px 2px rgba(15, 23, 42, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(15, 23, 42, 0.08), 0 2px 4px -1px rgba(15, 23, 42, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(15, 23, 42, 0.1), 0 4px 6px -2px rgba(15, 23, 42, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(15, 23, 42, 0.12), 0 10px 10px -5px rgba(15, 23, 42, 0.04);
    --shadow-2xl: 0 25px 50px -12px rgba(15, 23, 42, 0.25);
    --shadow-inner: inset 0 2px 4px 0 rgba(15, 23, 42, 0.06);
    
    /* Transitions */
    --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}


/* ============================================
   ACCESSIBILITY
   ============================================ */

.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--text-primary);
    color: white;
    padding: 8px 16px;
    text-decoration: none;
    border-radius: 0 0 4px 0;
    z-index: 10000;
    font-weight: 600;
    font-size: 0.875rem;
}

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


/* ============================================
   RESET & BASE STYLES
   ============================================ */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    overflow-x: hidden;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
    width: 100%;
    font-feature-settings: 'cv11', 'ss01';
    font-optical-sizing: auto;
}


/* ============================================
   TYPOGRAPHY
   ============================================ */

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    letter-spacing: -0.02em;
}

h2 {
    font-size: clamp(2.5rem, 5vw, 3.75rem);
    letter-spacing: -0.02em;
}

h3 {
    font-size: clamp(1.5rem, 3vw, 2rem);
}

.gradient-text {
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-mid) 50%, var(--gradient-end) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    background-size: 200% auto;
    animation: gradient-shift 8s ease infinite;
}

@keyframes gradient-shift {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

.text-body {
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text-secondary);
    font-weight: 400;
}

.text-body--bold {
    font-weight: 500;
    color: var(--text-primary);
}


/* ============================================
   NAVIGATION
   ============================================ */

.nav {
    position: fixed;
    top: 1.5rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
    padding: 0.875rem 1.75rem;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-radius: var(--radius-full);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: var(--shadow-lg), 0 0 0 1px rgba(15, 23, 42, 0.03);
    z-index: 1000;
    max-width: 1100px;
    width: 90%;
    transition: var(--transition-base);
}

.nav:hover {
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-xl), 0 0 0 1px rgba(15, 23, 42, 0.05);
}

.nav__logo {
    display: flex;
    align-items: center;
    gap: 0.625rem;
    cursor: pointer;
    transition: opacity var(--transition-base);
    text-decoration: none;
}

.nav__logo:hover {
    opacity: 0.8;
}

.nav__logo-icon {
    width: 48px;
    height: 48px;
    flex-shrink: 0;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    object-fit: contain;
    display: block;
}

.nav__logo:hover .nav__logo-icon {
    transform: rotate(360deg);
}

.nav__logo-text {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    letter-spacing: 0.02em;
}

.nav__links {
    display: flex;
    list-style: none;
    gap: 2rem;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}

.nav__link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 400;
    font-size: 0.95rem;
    transition: color var(--transition-base);
}

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

.nav__actions {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav__signin {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9375rem;
    transition: color var(--transition-base);
    white-space: nowrap;
}

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


/* ============================================
   BUTTONS
   ============================================ */

.btn {
    padding: 0.875rem 2rem;
    border: none;
    border-radius: var(--radius-full);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    display: inline-block;
    position: relative;
    overflow: hidden;
    font-family: 'Inter', sans-serif;
    letter-spacing: -0.01em;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.2), rgba(255, 255, 255, 0));
    opacity: 0;
    transition: opacity var(--transition-base);
}

.btn:hover::before {
    opacity: 1;
}

.btn--primary {
    background: transparent;
    color: white;
    padding: 0.75rem 1.75rem;
    font-size: 0.95rem;
    box-shadow: var(--shadow-md);
    border: none;
    position: relative;
    z-index: 1;
    overflow: hidden;
    isolation: isolate;
}

.btn--primary::after {
    content: '';
    position: absolute;
    inset: -2px;
    border-radius: var(--radius-full);
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-mid) 50%, var(--gradient-end) 100%);
    z-index: -1;
}

.btn--primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl), 0 0 20px rgba(99, 102, 241, 0.3);
}

.btn--secondary {
    background: white;
    color: var(--text-primary);
    border: none;
    position: relative;
    box-shadow: var(--shadow-md);
    z-index: 1;
    overflow: visible;
    transition: background 0.3s ease, color 0.3s ease, transform var(--transition-base), box-shadow var(--transition-base);
}

/* Gradient border using pseudo-element */
.btn--secondary::before {
    content: '';
    position: absolute;
    inset: -3px;
    border-radius: calc(var(--radius-full) + 3px);
    background: linear-gradient(135deg, 
        var(--gradient-start) 0%, 
        var(--gradient-mid) 50%, 
        var(--gradient-end) 100%);
    z-index: -1;
}

.btn--secondary:hover {
    background: linear-gradient(135deg, 
        var(--gradient-start) 0%, 
        var(--gradient-mid) 50%, 
        var(--gradient-end) 100%);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl), 0 0 20px rgba(99, 102, 241, 0.25);
}

.btn--large {
    padding: 1.125rem 2.75rem;
    font-size: 1.0625rem;
}


/* ============================================
   SECTIONS
   ============================================ */

.section {
    padding: 8rem 5%;
}

.section--white {
    background: var(--bg-white);
}

.section--gradient {
    background: var(--bg-gradient-light);
}

.section__title {
    text-align: center;
    margin-bottom: 4rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    position: relative;
    padding-bottom: 2rem;
}

.section__title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, 
        var(--gradient-start), 
        var(--gradient-mid), 
        var(--gradient-end));
    border-radius: 2px;
}


/* ============================================
   RESPONSIVE
   ============================================ */

@media (max-width: 968px) {
    .nav {
        gap: 1rem;
        padding: 0.75rem 1.25rem;
    }
    
    .nav__links {
        display: none;
    }
    
    .nav__actions {
        gap: 1rem;
    }
    
    .nav__signin {
        font-size: 0.875rem;
    }
    
    .section {
        padding: 5rem 5%;
    }
}


/* ============================================
   SCROLL ANIMATIONS
   ============================================ */

.split-section,
.solution-card,
.demo-section {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.animate-in {
    opacity: 1 !important;
    transform: translateY(0) !important;
}