/* ========================================
   LINGUAVOICE CORE DESIGN SYSTEM
   Complete rewrite with cohesive design
   ======================================== */

:root {
    /* Brand Colors */
    --navy-900: #0F172A;
    --navy-800: #1E293B;
    --navy-700: #334155;
    --emerald-500: #10B981;
    --emerald-600: #059669;
    --emerald-100: #D1FAE5;
    
    /* UI Colors */
    --bg-primary: #F8FAFC;
    --bg-secondary: #F1F5F9;
    --bg-card: #FFFFFF;
    --border-light: #E2E8F0;
    --text-primary: #1E293B;
    --text-secondary: #64748B;
    --text-muted: #94A3B8;
    
    /* Gradients */
    --gradient-hero: linear-gradient(135deg, #0F172A 0%, #1E293B 50%, #334155 100%);
    --gradient-accent: linear-gradient(135deg, #10B981 0%, #059669 100%);
    --gradient-soft: radial-gradient(at 0% 0%, rgba(16, 185, 129, 0.1) 0px, transparent 50%),
                     radial-gradient(at 100% 100%, rgba(15, 23, 42, 0.1) 0px, transparent 50%);
    
    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-12: 3rem;
    --space-16: 4rem;
    
    /* Typography */
    --font-display: 'Plus Jakarta Sans', system-ui, sans-serif;
    --font-body: 'Inter', system-ui, sans-serif;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
    font-family: var(--font-body);
    background: var(--bg-primary);
    background-image: var(--gradient-soft);
    background-attachment: fixed;
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 800;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

h1 { font-size: 3.5rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 1.875rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }

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

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

/* ========== LAYOUT ========== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.container-narrow {
    max-width: 800px;
}

/* ========== GLASS MORPHISM CARDS ========== */
.glass-card {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 1.5rem;
    box-shadow: var(--shadow-lg);
    padding: var(--space-8);
    transition: var(--transition-base);
}

.glass-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
    border-color: var(--emerald-500);
}

/* ========== BUTTONS ========== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.625rem;
    padding: 1rem 2rem;
    font-family: var(--font-display);
    font-size: 1.0625rem;
    font-weight: 800;
    border-radius: 1.125rem;
    border: none;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-decoration: none;
    white-space: nowrap;
}

.btn-primary {
    background: var(--gradient-accent);
    color: white;
    box-shadow: 0 4px 16px rgba(16, 185, 129, 0.35);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(16, 185, 129, 0.45);
}

.btn-primary:active {
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(16, 185, 129, 0.35);
}

.btn-secondary {
    background: white;
    color: var(--navy-900);
    border: 2.5px solid var(--border-light);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.btn-secondary:hover {
    border-color: var(--emerald-500);
    background: var(--emerald-100);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.15);
}

.btn-large {
    padding: 1.25rem 3rem;
    font-size: 1.1875rem;
}

/* ========== FORMS ========== */
.form-group {
    margin-bottom: var(--space-6);
}

.form-label {
    display: block;
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--navy-900);
    margin-bottom: var(--space-2);
    letter-spacing: 0.025em;
}

.form-input {
    width: 100%;
    padding: var(--space-4);
    font-family: var(--font-body);
    font-size: 1rem;
    border: 2px solid var(--border-light);
    border-radius: 0.75rem;
    background: white;
    transition: var(--transition-base);
}

.form-input:focus {
    outline: none;
    border-color: var(--emerald-500);
    box-shadow: 0 0 0 4px rgba(16, 185, 129, 0.1);
}

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

/* ========== NAVIGATION ========== */
.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 2px solid var(--border-light);
    padding: 1.25rem 0;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
}

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

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.875rem;
    font-family: var(--font-display);
    font-weight: 900;
    font-size: 1.625rem;
    color: var(--navy-900);
    transition: transform 0.2s ease;
}

.nav-brand:hover {
    transform: scale(1.02);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-link {
    padding: 0.75rem 1.5rem;
    font-weight: 700;
    font-size: 1rem;
    color: var(--text-secondary);
    border-radius: 0.875rem;
    transition: all 0.25s ease;
    white-space: nowrap;
}

.nav-link:hover {
    color: var(--navy-900);
    background: var(--emerald-100);
    transform: translateY(-2px);
}

.nav-link.active {
    color: white;
    background: var(--gradient-accent);
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
}

/* ========== UTILITY CLASSES ========== */
.text-center { text-align: center; }
.text-gradient {
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.gap-2 { gap: var(--space-2); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }

.mt-4 { margin-top: var(--space-4); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-8 { margin-bottom: var(--space-8); }
.mb-12 { margin-bottom: var(--space-12); }

/* ========== ANIMATIONS ========== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-in {
    animation: fadeInUp 0.6s ease-out;
}

.animate-delay-1 { animation-delay: 0.1s; }
.animate-delay-2 { animation-delay: 0.2s; }
.animate-delay-3 { animation-delay: 0.3s; }

/* Pulse animation for CTAs */
@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

.animate-pulse {
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

/* ========== RESPONSIVE ========== */
@media (max-width: 768px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }
    
    .container {
        padding: 0 1.25rem;
    }
    
    .navbar {
        padding: 1rem 0;
    }
    
    .nav-brand {
        font-size: 1.375rem;
    }
    
    .nav-links {
        gap: 0.25rem;
    }
    
    .nav-link {
        padding: 0.625rem 1rem;
        font-size: 0.9375rem;
    }
    
    .btn {
        padding: 0.875rem 1.5rem;
        font-size: 1rem;
    }
    
    .btn-large {
        padding: 1rem 2rem;
        font-size: 1.0625rem;
    }
}